WorldWideScience

Sample records for ps freely traverses

  1. Induced vibrations facilitate traversal of cluttered obstacles

    Science.gov (United States)

    Thoms, George; Yu, Siyuan; Kang, Yucheng; Li, Chen

    When negotiating cluttered terrains such as grass-like beams, cockroaches and legged robots with rounded body shapes most often rolled their bodies to traverse narrow gaps between beams. Recent locomotion energy landscape modeling suggests that this locomotor pathway overcomes the lowest potential energy barriers. Here, we tested the hypothesis that body vibrations induced by intermittent leg-ground contact facilitate obstacle traversal by allowing exploration of locomotion energy landscape to find this lowest barrier pathway. To mimic a cockroach / legged robot pushing against two adjacent blades of grass, we developed an automated robotic system to move an ellipsoidal body into two adjacent beams, and varied body vibrations by controlling an oscillation actuator. A novel gyroscope mechanism allowed the body to freely rotate in response to interaction with the beams, and an IMU and cameras recorded the motion of the body and beams. We discovered that body vibrations facilitated body rolling, significantly increasing traversal probability and reducing traversal time (P probability increased with and traversal time decreased with beam separation. These results confirmed our hypothesis and support the plausibility of locomotion energy landscapes for understanding the formation of locomotor pathways in complex 3-D terrains.

  2. Inflatable traversing probe seal

    Science.gov (United States)

    Trimarchi, Paul A.

    1991-01-01

    An inflatable seal acts as a pressure-tight zipper to provide traversing capability for instrumentation rakes and probes. A specially designed probe segment with a teardrop cross-section in the vicinity of the inflatable seal minimizes leakage at the interface. The probe is able to travel through a lengthwise slot in a pressure vessel or wind tunnel section, while still maintaining pressure integrity. The design uses two commercially available inflatable seals, opposing each other, to cover the probe slot in a wind tunnel wall. Proof-of-concept tests were conducted at vessel pressures up to 30 psig, with seals inflated to 50 psig, showing no measurable leakage along the seal's length or around the probe teardrop cross-section. This seal concept can replace the existing technology of sliding face plate/O-ring systems in applications where lengthwise space is limited.

  3. Term rewriting with traversal functions

    NARCIS (Netherlands)

    J.J. Vinju (Jurgen); M.G.J. van den Brand (Mark); P. Klint (Paul)

    2003-01-01

    htmlabstractTerm rewriting is an appealing technique for performing program analysis and program transformation. Tree (term) traversal is frequently used but is not supported by standard term rewriting. We extend many-sorted, first-order term rewriting with traversal functions that automate tree

  4. Visitor combination and traversal control

    NARCIS (Netherlands)

    J.M.W. Visser (Joost)

    2001-01-01

    textabstractThe emph{Visitor design pattern allows the encapsulation of polymorphic behavior outside the class hierarchy on which it operates. A common application of emph{Visitor is the encapsulation of tree traversals. Unfortunately, visitors resist composition and allow little traversal control.

  5. Diving into traversable wormholes

    Science.gov (United States)

    Maldacena, Juan; Stanford, Douglas; Yang, Zhenbin

    2017-05-01

    We study various aspects of wormholes that are made traversable by an interaction beween the two asymptotic boundaries. We concentrate on the case of nearly-$AdS_2$ gravity and discuss a very simple mechanical picture for the gravitational dynamics. We derive a formula for the two sided correlators that includes the effect of gravitational backreaction, which limits the amount of information we can send through the wormhole. We emphasize that the process can be viewed as a teleportation protocol where the teleportee feels nothing special as he/she goes through the wormhole. We discuss some applications to the cloning paradox for old black holes. We point out that the same formula we derived for $AdS_2$ gravity is also valid for the simple SYK quantum mechanical theory, around the thermofield double state. We present a heuristic picture for this phenomenon in terms of an operator growth model. Finally, we show that a similar effect is present in a completely classical chaotic system with a large number of degrees of freedom.

  6. PS buildings : reinforced concrete structure for shielding "bridge" pillar

    CERN Multimedia

    CERN PhotoLab

    1956-01-01

    The PS ring traverses the region between the experimental halls South and North (buildings Nos 150 and 151) under massive bridge-shaped concrete beams. This pillar stands at the S-W end of the structure.

  7. Generalising tree traversals to DAGs

    DEFF Research Database (Denmark)

    Bahr, Patrick; Axelsson, Emil

    2015-01-01

    We present a recursion scheme based on attribute grammars that can be transparently applied to trees and acyclic graphs. Our recursion scheme allows the programmer to implement a tree traversal and then apply it to compact graph representations of trees instead. The resulting graph traversals avoid...... is not sound. Therefore, we complement our implementation of the recursion scheme with a number of correspondence theorems that ensure soundness for various classes of traversals. We illustrate the practical applicability of the implementation as well as the complementing theory with a number of examples....

  8. Chaotic Traversal (CHAT): Very Large Graphs Traversal Using Chaotic Dynamics

    Science.gov (United States)

    Changaival, Boonyarit; Rosalie, Martin; Danoy, Grégoire; Lavangnananda, Kittichai; Bouvry, Pascal

    2017-12-01

    Graph Traversal algorithms can find their applications in various fields such as routing problems, natural language processing or even database querying. The exploration can be considered as a first stepping stone into knowledge extraction from the graph which is now a popular topic. Classical solutions such as Breadth First Search (BFS) and Depth First Search (DFS) require huge amounts of memory for exploring very large graphs. In this research, we present a novel memoryless graph traversal algorithm, Chaotic Traversal (CHAT) which integrates chaotic dynamics to traverse large unknown graphs via the Lozi map and the Rössler system. To compare various dynamics effects on our algorithm, we present an original way to perform the exploration of a parameter space using a bifurcation diagram with respect to the topological structure of attractors. The resulting algorithm is an efficient and nonresource demanding algorithm, and is therefore very suitable for partial traversal of very large and/or unknown environment graphs. CHAT performance using Lozi map is proven superior than the, commonly known, Random Walk, in terms of number of nodes visited (coverage percentage) and computation time where the environment is unknown and memory usage is restricted.

  9. Five dimensional cosmological traversable wormhole

    Energy Technology Data Exchange (ETDEWEB)

    Najafi, S.; Rostami, T., E-mail: t_rostami@sbu.ac.ir; Jalalzadeh, S., E-mail: s-jalalzadeh@sbu.ac.ir

    2015-03-15

    In this paper, a traversable wormhole in the Friedmann–Lemaître–Robertson–Walker (FLRW) model with one extra spacelike compact dimension is studied. We have chosen dynamical compactification as the evolution of the fifth dimension. In this respect, we study how the existence of the extra dimension affects the behavior of the energy density, the shape function and the scale factor. It is shown that the total matter can be non-exotic and the violation of the weak energy condition can be avoided.

  10. Traversable Schwarzschild-like wormholes

    Science.gov (United States)

    Cataldo, Mauricio; Liempi, Luis; Rodríguez, Pablo

    2017-11-01

    In this paper we study relativistic static traversable wormhole solutions which are a slight generalization of Schwarzschild wormholes. In order to do this we assume a shape function with a linear dependence on the radial coordinate r. This linear shape function generates wormholes whose asymptotic spacetime is not flat: they are asymptotically locally flat, since in the asymptotic limit r → ∞ spacetimes exhibiting a solid angle deficit (or excess) are obtained. In particular, there exist wormholes which connect two asymptotically non-flat regions with a solid angle deficit. For these wormholes the size of their embeddings in a three-dimensional Euclidean space extends from the throat to infinity. A new phantom zero-tidal-force wormhole exhibiting such asymptotic is obtained. On the other hand, if a solid angle excess is present, the size of the wormhole embeddings depends on the amount of this angle excess, and the energy density is negative everywhere. We discuss the traversability conditions and study the impact of the β -parameter on the motion of a traveler when the wormhole throat is crossed. A description of the geodesic behavior for the wormholes obtained is also presented.

  11. Freely rising light solid spheres

    NARCIS (Netherlands)

    Veldhuis, Christian; Biesheuvel, A.; Lohse, Detlef

    2009-01-01

    This paper examines the behavior of spheres rising freely in a Newtonian fluid when the ratio between the density of the spheres and that of the surrounding fluid is about 0.02. High-speed imaging is used to reconstruct three-dimensional trajectories of the rising spheres. From the analysis of the

  12. Typed generic traversals in $S_gamma^'$

    NARCIS (Netherlands)

    R. Lämmel (Ralf)

    2001-01-01

    textabstractA typed model of strategic rewriting is developed. An innovation is that generic traversals are covered. To this end, we define a rewriting calculus $S'_{gamma$. The calculus offers a few strategy combinators for generic traversals. There is, for example, a combinator to apply a strategy

  13. Static traversable wormholes in Lyra manifold

    Science.gov (United States)

    Jahromi, A. Sayahian; Moradpour, H.

    At first, considering the Einstein framework, we introduce some new static traversable wormholes and study the effects of a dark energy-like source on them. Thereinafter, a brief review on Einstein field equations in Lyra manifold is presented, and we address some static traversable wormholes in the Lyra manifold which satisfy the energy conditions. It is also shown that solutions introduced in the Einstein framework may also meet the energy conditions in the Lyra manifold. Finally, we focus on vacuum Lyra manifold and find some traversable asymptotically flat wormholes. In summary, our study shows that it is theoretically possible to find a Lyra displacement vector field in a manner in which traversable wormholes satisfy the energy conditions in a Lyra manifold.

  14. RTSAH Traversal Order for Occlusion Rays

    KAUST Repository

    Ize, Thiago

    2011-04-01

    We accelerate the finding of occluders in tree based acceleration structures, such as a packetized BVH and a single ray kd-tree, by deriving the ray termination surface area heuristic (RTSAH) cost model for traversing an occlusion ray through a tree and then using the RTSAH to determine which child node a ray should traverse first instead of the traditional choice of traversing the near node before the far node. We further extend RTSAH to handle materials that attenuate light instead of fully occluding it, so that we can avoid superfluous intersections with partially transparent objects. For scenes with high occlusion, we substantially lower the number of traversal steps and intersection tests and achieve up to 2× speedups. © 2010 The Author(s).

  15. Traversable wormholes via a double trace deformation

    Science.gov (United States)

    Gao, Ping; Jafferis, Daniel Louis; Wall, Aron C.

    2017-12-01

    After turning on an interaction that couples the two boundaries of an eternal BTZ black hole, we find a quantum matter stress tensor with negative average null energy, whose gravitational backreaction renders the Einstein-Rosen bridge traversable. Such a traversable wormhole has an interesting interpretation in the context of ER=EPR, which we suggest might be related to quantum teleportation. However, it cannot be used to violate causality. We also discuss the implications for the energy and holographic entropy in the dual CFT description.

  16. First-class rules and generic traversal

    NARCIS (Netherlands)

    Dolstra, E.; Visser, Eelco

    2001-01-01

    In this paper we present a functional language supporting first-class rules and generic traversal. This is achieved by generalizing the pattern matching constructs of standard functional languages. The case construct that ties rules together and prevents their reuse, is replaced by separate,

  17. Traverse Planning with Temporal-Spatial Constraints

    Science.gov (United States)

    Bresina, John L.; Morris, Paul H.; Deans, Mathew C.; Cohen, Tamar E.; Lees, David S.

    2017-01-01

    We present an approach to planning rover traverses in a domain that includes temporal-spatial constraints. We are using the NASA Resource Prospector mission as a reference mission in our research. The objective of this mission is to explore permanently shadowed regions at a Lunar pole. Most of the time the rover is required to avoid being in shadow. This requirement depends on where the rover is located and when it is at that location. Such a temporal-spatial constraint makes traverse planning more challenging for both humans and machines. We present a mixed-initiative traverse planner which addresses this challenge. This traverse planner is part of the Exploration Ground Data Systems (xGDS), which we have enhanced with new visualization features, new analysis tools, and new automation for path planning, in order to be applicable to the Re-source Prospector mission. The key concept that is the basis of the analysis tools and that supports the automated path planning is reachability in this dynamic environment due to the temporal-spatial constraints.

  18. Message passing with parallel queue traversal

    Science.gov (United States)

    Underwood, Keith D [Albuquerque, NM; Brightwell, Ronald B [Albuquerque, NM; Hemmert, K Scott [Albuquerque, NM

    2012-05-01

    In message passing implementations, associative matching structures are used to permit list entries to be searched in parallel fashion, thereby avoiding the delay of linear list traversal. List management capabilities are provided to support list entry turnover semantics and priority ordering semantics.

  19. Last PS magnet refurbished

    CERN Document Server

    2009-01-01

    PS Magnet Refurbishment Programme Completed. The 51st and final refurbished magnet was transported to the PS on Tuesday 3 February. The repair and consolidation work on the PS started back in 2003 when two magnets and a busbar connection were found to be faulty during routine high-voltage tests. The cause of the fault was a combination of age and radiation on electrical insulation. After further investigation the decision was taken to overhaul half of the PS’s 100 magnets to reduce the risk of a similar fault. As from 20 February the PS ring will start a five-week test programme to be ready for operation at the end of March.

  20. Traversable asymptotically flat wormholes in Rastall gravity

    Science.gov (United States)

    Moradpour, H.; Sadeghnezhad, N.; Hendi, S. H.

    2017-12-01

    There are some gravitational theories in which the ordinary energy-momentum conservation law is not valid in the curved spacetime. Rastall gravity is one of the known theories in this regard which includes a non-minimal coupling between geometry and matter fields. Equipped with the basis of such theory, we study the properties of traversable wormholes with flat asymptotes. We investigate the possibility of exact solutions by a source with the baryonic matter state parameter. Our survey indicates that Rastall theory has considerable effects on the wormhole characteristics. In addition, we study various case studies and show that the weak energy condition may be met for some solutions. We also give a discussion regarding to traversability of such wormhole geometry with phantom sources.

  1. Traversing the Fantasy of the Heroic Entrepreneur

    DEFF Research Database (Denmark)

    Garmann Johnsen, Christian; Meier Sørensen, Bent

    2017-01-01

    is to traverse the fantasy of the heroic entrepreneur by offering a reading of Richard Branson’s autobiography, Losing My Virginity. Design/methodology/approach: The theoretical approach of this paper is informed by Slavoj Žižek’s concept of fantasy and his critical analytical strategy of “traversing the fantasy...... not only of the economy, but of being as such. Originality/value: Rather than striving towards a processual approach that lays emphasis on the collective effort involved in entrepreneurship, this paper critically engages directly with the heroic entrepreneur by exploring how this figure is a fantasy...... that structures desire. This paper shows how critical entrepreneurship studies could benefit from an approach that analyses how the cultural representation of business celebrates the heroic entrepreneur as a source of value creation. The authors further argue that it is the contradictions and impossibilities...

  2. Ice Velocities Around the 2000 Meter Traverse in Greenland

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains traverse measurements used to infer the mass balance of central parts of the ice sheet upslope from the traverse, and results from this work...

  3. T-transformation: traversability analysis for navigation on rugged terrain

    Science.gov (United States)

    Ye, Cang; Borenstein, Johann

    2004-09-01

    In order to maneuver autonomously on rough terrain, a mobile robot must constantly decide whether to traverse or circumnavigate terrain features ahead. This ability is called Obstacle Negotiation (ON). A critical aspect of ON is the so-called traversability analysis, which evaluates the level of difficulty associated with the traversal of the terrain. This paper presents a new method for traversability analysis, called T-transformation. It is implemented in a local terrain map as follows: (1) For each cell in the local terrain map, a square terrain patch is defined that symmetrically overlays the cell; (2) a plane is fitted to the data points in the terrain patch using a least-square approach and the slope of the least-squares plane and the residual of the fit are computed and used to calculate the Traversability Index (TI) for that cell; (3) after each cell is assigned a TI value, the local terrain map is transformed into a traversability map. The traversability map is further transformed into a traversability field histogram where each element represents the overall level of difficulty to move along the corresponding direction. Based on the traversability field histogram our reactive ON system then computes the steering and velocity commands to move the robot toward the intended goal while avoiding areas of poor traversability. The traversability analysis algorithm and the overall ON system were verified by extensive simulation. We verified our method partially through experiments on a Segway Robotics Mobility Platform (RMP), albeit only on flat terrain.

  4. pinktoe: Semi-automatic Traversal of Trees

    OpenAIRE

    Guy Nason

    2005-01-01

    Tree based methods in S or R are extremely useful and popular. For simple trees and memorable variables it is easy to predict the outcome for a new case using only a standard decision tree diagram. However, for large trees or trees where the variable description is complex the decision tree diagram is often not enough. This article describes pinktoe: an R package containing two tools to assist with the semiautomatic traversal of trees. The PT tool creates a widget for each node to be visited ...

  5. Traversable braneworld wormholes supported by astrophysical observations

    Science.gov (United States)

    Wang, Deng; Meng, Xin-He

    2018-02-01

    In this study, we investigate the characteristics and properties of a traversable wormhole constrained by the current astrophysical observations in the framework of modified theories of gravity (MOG). As a concrete case, we study traversable wormhole space-time configurations in the Dvali-Gabadadze-Porrati (DGP) braneworld scenario, which are supported by the effects of the gravity leakage of extra dimensions. We find that the wormhole space-time structure will open in terms of the 2 σ confidence level when we utilize the joint constraints supernovae (SNe) Ia + observational Hubble parameter data (OHD) + Planck + gravitational wave (GW) and z wormholes can be divided into four classes during the evolutionary processes of the universe based on various energy conditions; (ii) we can offer a strict restriction to the local wormhole space-time structure by using the current astrophysical observations; and (iii) we can clearly identify a physical gravitational resource for the wormholes supported by astrophysical observations, namely the dark energy components of the universe or equivalent space-time curvature effects from MOG. Moreover, we find that the strong energy condition is always violated at low redshifts.

  6. Inside the PS tunnel

    CERN Multimedia

    1974-01-01

    Pre-start work is going on at the end of the PS long shut-down. The photo shows secondary beams drawn from an internal target (bottom) towards South Hall, behind the shielding wall (top) (see also photo 7409012X).

  7. PS Control Room

    CERN Multimedia

    CERN PhotoLab

    1963-01-01

    The good old PS Control Room, all manual. For each parameter, a knob or a button to control it; for each, a light or meter or oscilloscope to monitor it; carefully written pages serve as the data bank; phones and intercom for communication. D.Dekkers is at the microphone, M.Valvini sits in front.

  8. PS auxiliary magnet

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    Units of the PS auxiliary magnet system. The picture shows how the new dipoles, used for vertical and horizontal high-energy beam manipulation, are split for installation and removal so that it is not necessary to break the accelerator vacuum. On the right, adjacent to the sector valve and the windings of the main magnet, is an octupole of the set.

  9. Queen Maud Land Traverses: Surface Glaciology (Invited)

    Science.gov (United States)

    Cameron, R. L.

    2009-12-01

    One of the main tasks of a glaciologist is to determine the mass budget of a glacier; and snow accumulation is the first part of the equation. To do this, a great number of snow pits must be dug to analyze the stratigraphy. A. P. Crary once said “to be a glaciologist one should first of all love to dig snow pits.” Seventy-five snow pits were dug on the SPQMLT traverses. Several experienced glaciologists had difficulty in interpreting the stratigraphic sequences in these pits. Irregular layering, caused by uneven deposition and subsequent erosion, suggested that some of the layers could be missing. However, the fallout of artificial radioactive nuclides released by the first large thermonuclear bomb test, on March 1, 1954, at Castle Bravo on Bikini Atoll, Marshall Islands, produced a datum horizon over the Antarctic ice sheet. This horizon is the summer of 1954-55 and provides the basis for measuring the average accumulation since 1955. Accumulation varied from 6.7 ± 0.2 g cm-2 yr-1 at South Pole Station to a low of 0.6 ± 0.2 g cm-2 yr-1 in a pit on the second leg of SPQMLT 2. The average accumulation along the entire traverse route was 3.7 g cm-2 yr-1. Temperatures at ten meters (considered an approximate mean annual air temperature) varied from -58.4 degrees Centigrade at Plateau Station (elevation 3620 meters) to -38 degrees Centigrade at the terminus of SPQMLT 3 (elevation 2310 meters). The condition of the ice sheet surface varied considerably. Some surface was quite hard and easy to traverse; while other areas that were smooth and soft were troublesome enough to bog down vehicles and sleds. Sastrugi were sporadic with some as high as a meter. A large crevasse field forced a slight change in course toward the end of the first leg of SPQMLT 2. There the ice thickness changed dramatically from 3060 meters to 1852 meters. At the time the geophysicist said, “The ‘bottom’ came up so fast I thought we would hit a nunatak.”

  10. Quantifying Traversability of Terrain for a Mobile Robot

    Science.gov (United States)

    Howard, Ayanna; Seraji, Homayoun; Werger, Barry

    2005-01-01

    A document presents an updated discussion on a method of autonomous navigation for a robotic vehicle navigating across rough terrain. The method involves, among other things, the use of a measure of traversability, denoted the fuzzy traversability index, which embodies the information about the slope and roughness of terrain obtained from analysis of images acquired by cameras mounted on the robot. The improvements presented in the report focus on the use of the fuzzy traversability index to generate a traversability map and a grid map for planning the safest path for the robot. Once grid traversability values have been computed, they are utilized for rejecting unsafe path segments and for computing a traversalcost function for ranking candidate paths, selected by a search algorithm, from a specified initial position to a specified final position. The output of the algorithm is a set of waypoints designating a path having a minimal-traversal cost.

  11. Intracranial neurenteric cyst traversing the brainstem

    Directory of Open Access Journals (Sweden)

    Jasmit Singh

    2015-01-01

    Full Text Available Neurenteric cysts (NECs, also called enterogenous cysts, are rare benign endodermal lesions of the central nervous system that probably result from separation failure of the notochord and upper gastrointestinal tract. Most frequently they are found in the lower cervical spine or the upper thoracic spine. Intracranial occurrence is rare and mostly confined to infratentorial compartment, in prepontine region [51%]. Other common locations are fourth ventricle and cerebellopontine angle. There are few reports of NEC in medulla or the cerebellum. Because of the rarity of the disease and common radiological findings, they are misinterpreted as arachnoid or simple cysts until the histopathological confirmation, unless suspected preoperatively. We herein report a rare yet interesting case of intracranial NEC traversing across the brainstem.

  12. pinktoe: Semi-automatic Traversal of Trees

    Directory of Open Access Journals (Sweden)

    Guy P. Nason

    2005-04-01

    Full Text Available Tree based methods in S or R are extremely useful and popular. For simple trees and memorable variables it is easy to predict the outcome for a new case using only a standard decision tree diagram. However, for large trees or trees where the variable description is complex the decision tree diagram is often not enough. This article describes pinktoe: an R package containing two tools to assist with the semiautomatic traversal of trees. The PT tool creates a widget for each node to be visited in the tree that is needed to make a decision and permits the user to make decisions using radiobuttons. The pinktoe function generates a suite of HTML and Perl files that permit a CGI-enabled website to issue step-by-step questions to a user wishing to make a prediction using a tree.

  13. PS injection area

    CERN Multimedia

    1974-01-01

    Looking against the direction of protons in the main ring (left): the beam coming from the linac 1 either goes to the booster (on the right) or is deflected towards the PS to be directly injected into section 26 (facing the camera). Also shown the start of the TT2 line, ejected from straight section 16 to go towards the ISR passing over the beam line from the linac. (see Photo Archive 7409009)

  14. PS injection area

    CERN Multimedia

    1974-01-01

    To the right is the PS ring viewed along the direction of the protons. At the left the injection line coming from the 50 MeV Linac 1 (bottom) and going towards the 800 MeV booster, or deflected to the right to be injected directly into straight section 16. The drumlike element behind the (blue) dipole magnet is a 'debuncher' (a 200 MHz cavity). See photos 7409014X and 7409009.

  15. A freely-moving monkey treadmill model

    Science.gov (United States)

    Foster, Justin D.; Nuyujukian, Paul; Freifeld, Oren; Gao, Hua; Walker, Ross; Ryu, Stephen I.; Meng, Teresa H.; Murmann, Boris; Black, Michael J.; Shenoy, Krishna V.

    2014-08-01

    Objective. Motor neuroscience and brain-machine interface (BMI) design is based on examining how the brain controls voluntary movement, typically by recording neural activity and behavior from animal models. Recording technologies used with these animal models have traditionally limited the range of behaviors that can be studied, and thus the generality of science and engineering research. We aim to design a freely-moving animal model using neural and behavioral recording technologies that do not constrain movement. Approach. We have established a freely-moving rhesus monkey model employing technology that transmits neural activity from an intracortical array using a head-mounted device and records behavior through computer vision using markerless motion capture. We demonstrate the flexibility and utility of this new monkey model, including the first recordings from motor cortex while rhesus monkeys walk quadrupedally on a treadmill. Main results. Using this monkey model, we show that multi-unit threshold-crossing neural activity encodes the phase of walking and that the average firing rate of the threshold crossings covaries with the speed of individual steps. On a population level, we find that neural state-space trajectories of walking at different speeds have similar rotational dynamics in some dimensions that evolve at the step rate of walking, yet robustly separate by speed in other state-space dimensions. Significance. Freely-moving animal models may allow neuroscientists to examine a wider range of behaviors and can provide a flexible experimental paradigm for examining the neural mechanisms that underlie movement generation across behaviors and environments. For BMIs, freely-moving animal models have the potential to aid prosthetic design by examining how neural encoding changes with posture, environment and other real-world context changes. Understanding this new realm of behavior in more naturalistic settings is essential for overall progress of basic

  16. At PS170 (APPLE)

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    APPLE stands for Antiproton-Proton to Pair of LEptons (an acronym of the ancestor experiment PAPLEP), the PS170 experiment setup at LEAR to study e+e-pair production in antiproton-proton annihilation by Padova-(CEN) Saclay- Torino Collaboration. It consisted of a liquid hydrogen target surrounded by several layers of proportional chambers in the vertical field of a C-magnet (this photo), a gas Cerenkov counter, wire chambers, hodoscopes, and an electromagnetic calorimeter (see photo 8302539X, 8302540X). See also photo 8301539X for the setup assembly at an early stage.

  17. Brainstem neurons responsible for postural, masseter or pharyngeal muscle atonia during paradoxical sleep in freely-moving cats.

    Science.gov (United States)

    Sakai, K; Neuzeret, P-C

    2011-12-01

    In this mini review, we summarize our findings regarding the brainstem neurons responsible for the postural, masseter, or pharyngeal muscle atonia observed during paradoxical sleep (PS) in freely moving cats. Both the pons and medulla contain neurons showing tonic activation selective to PS and atonia, referred to as PS/atonia-on-neurons. The PS/atonia-on neurons, characterized by their most slow conducting property and located in the peri-locus coeruleus alpha (peri-LCa) and adjacent LCa of the mediodorsal pontine tegmentum, play a critical executive role in the somatic and orofacial muscle atonia observed during PS. Slow conducting medullary PS/atonia-on neurons located in the nuclei reticularis magnocellularis (Mc) and parvocellularis (Pc) may play a critical executive role in the generation of, respectively, antigravity or orofacial muscle atonia during PS. In addition, either tonic or phasic cessation of activity of medullary serotonergic neurons may play an important role in the atonia of genioglossus muscles during PS via a mechanism of disfacilitation.

  18. Traversability Analysis for Unmanned Ground Vehicles: Interpreting the Environment

    Science.gov (United States)

    2006-12-01

    a geometric representation of the environment , called a Terrain Map, from exteroceptive and proprioceptive data streams. This Terrain Map can further...Traversability Map interprets geometric data by calculating statistics about the environment to determine whether an area is traversable or not. In doing

  19. Traverse Planning Experiments for Future Planetary Surface Exploration

    Science.gov (United States)

    Hoffman, Stephen J.; Voels, Stephen A.; Mueller, Robert P.; Lee, Pascal C.

    2012-01-01

    The purpose of the investigation is to evaluate methodology and data requirements for remotely-assisted robotic traverse of extraterrestrial planetary surface to support human exploration program, assess opportunities for in-transit science operations, and validate landing site survey and selection techniques during planetary surface exploration mission analog demonstration at Haughton Crater on Devon Island, Nunavut, Canada. Additionally, 1) identify quality of remote observation data sets (i.e., surface imagery from orbit) required for effective pre-traverse route planning and determine if surface level data (i.e., onboard robotic imagery or other sensor data) is required for a successful traverse, and if additional surface level data can improve traverse efficiency or probability of success (TRPF Experiment). 2) Evaluate feasibility and techniques for conducting opportunistic science investigations during this type of traverse. (OSP Experiment). 3) Assess utility of remotely-assisted robotic vehicle for landing site validation survey. (LSV Experiment).

  20. Beyond iPS!

    Directory of Open Access Journals (Sweden)

    Editorial

    2012-01-01

    Full Text Available It’s undoubtedly a jubilant moment for scientists and clinicians working in the stem cell arena as Prof. Gurdon and Prof. Shinya Yamanaka have been chosen for the Nobel Prize in Physiology & Medicine this year. The mystery of cell biology is something unfathomable and probably the work of this duo as well as the other scientists, who have put their hands on in- vitro de-differentiation have opened our eyes to a new window or a new paradigm in cell biology. The iPS invention has brought a lot of hope in terms of potential direct benefits to treat several diseases, which have no definite options at the moment. But, we envisage that several spin-offs could come out of this invention and one very significant spin-off finding recently witnessed is the finding by Prof. Masaharu Seno and his team of researchers at the Okayama University, Japan (Chen L, et al. 2012, PLoS ONE 7(4:e33544.doi:10.1371/journal.pone.0033544. According to Prof. Seno, mouse iPS cells (miPS when cultured in the conditioned medium derived from cancer cell lines, differentiate into cancer stem cells (CSCs. While differentiating into CSCs, they do retain the potential to develop endothelial progenitor cells. Several questions arise here: 1.Are these miPS derived CSCs really pluripotent, even if the terminal differentiation destined to specific phenotypes? 2.Shouldn’t the Cancer Stem Cells be termed as cancer progenitor cells, as till date they are considered to be producing only cancer cells but not pluripotent to yield other types of normal tissues? The spin-offs could be infinite as the process of differentiation and de-differentiation happening due to trillions of signals and pathways, most still remaining not-so-well understood. A special mention should be made to Prof. Shinya Yamanaka as he has several sterling qualities to be a role-model for budding scientists. Apart from his passion for science, which made him shift his career from orthopedics to a cell biologist, his

  1. Mars Rover Curiosity Traverses of Sand Ripples

    Science.gov (United States)

    Stein, N.; Arvidson, R. E.; Zhou, F.; Heverly, M.; Maimone, M.; Hartman, F.; Bellutta, P.; Iagnemma, K.; Senatore, C.

    2014-12-01

    Martian sand ripples present a challenge for rover mobility, with drives over ripples often characterized by high wheel sinkage and slippage that can lead to incipient embedding. Since landing in Gale Crater, Curiosity has traversed multiple sand ripples, including the transverse aeolian ridge (TAR) straddling Dingo Gap on sols 533 and 535. On sol 672, Curiosity crossed backward over a series of sand ripples before ending its drive after high motor currents initiated visual odometry (VO) processing, which detected 77% slip, well in excess of the imposed 60% slip limit. At the end of the drive, the right front wheel was deeply embedded at the base of a ripple flank with >20 cm sinkage and the rear wheels were near a ripple crest. As Curiosity continues its approach to Mount Sharp it will have to cross multiple ripples, and thus it is important to understand Curiosity's performance on sol 672 and over similar ripples. To this end the sol 672 drive was simulated in ARTEMIS (Adams-Based Rover Terramechanics Interaction Simulator), a software tool consisting of realistic rover mechanical models, a wheel-terrain interaction module for deformable and non-deformable surfaces, and realistic terrain models. ARTEMIS results, Dumont Dunes tests performed in the Mojave Desert using the Scarecrow test rover, and single wheel tests performed at MIT indicate that the high slip encountered on sol 672 likely occurred due to a combination of rover attack angle, ripple geometry, and soil properties. When ripple wavelength approaches vehicle length, the rover can reach orientations in which the leading wheels carry minimal normal loads and the trailing wheels sink deeply, resulting in high slippage and insufficient thrust to propel the rover over ripples. Even on relatively benign (i.e. low tilt) terrains, local morphology can impose high sinkage, thus impeding rover motion. Work is underway to quantify Curiosity's drive performance over various ripple geometries to retrieve soil

  2. Proposal of a personal mobility vehicle capable of traversing rough terrain.

    Science.gov (United States)

    Nakajima, Shuro

    2014-05-01

    Personal mobility vehicles (PMVs) are now being actively developed. Most PMVs are wheel-driven, a mode of transport notable for its efficiency. However, such vehicles tend to have little mobility over rough terrain. We propose a new type of PMV, a vehicle that traverses relatively smooth terrain by wheel but is capable of negotiating rough terrain by using its wheel mechanisms as legs. The PMV we propose is intended to provide its user with a degree of outdoor mobility in daily urban life, say when going to a neighbourhood shop or simply taking a stroll. We do not consider elevators and other infrastructural elements that should be barrier-free, but rather focus on unimproved terrains that act as barriers to transport; for example, the steps that often act as de facto boundaries around building entrances. We developed a new type of PMV and implemented a new algorithm to realize the capability to move on rough terrain. We experimentally compared the capability of a commercially available PMV and the developed PMV. Through an experiment involving the traversing of a representative terrain and a comparative experiment using a stock PMV, we demonstrated the features of the proposed PMV. We developed a single-seat personal mobility vehicle, the RT-Mover PType 3, which is capable of traversing steps and other unimproved terrain often found within an urban environment. RT-Mover PType 3 can handle oblique slopes and other terrain that can be quite difficult to negotiate with a conventional electric wheelchair, thus enabling individuals with impaired mobility to move freely about urban environments. The current vehicle is primarily intended for the active elderly and other individuals in fairly good health, although, through further research and development, we do hope to extend its usefulness to those with substantial mobility impairments.

  3. Virtual reality for freely moving animals.

    Science.gov (United States)

    Stowers, John R; Hofbauer, Maximilian; Bastien, Renaud; Griessner, Johannes; Higgins, Peter; Farooqui, Sarfarazhussain; Fischer, Ruth M; Nowikovsky, Karin; Haubensak, Wulf; Couzin, Iain D; Tessmar-Raible, Kristin; Straw, Andrew D

    2017-10-01

    Standard animal behavior paradigms incompletely mimic nature and thus limit our understanding of behavior and brain function. Virtual reality (VR) can help, but it poses challenges. Typical VR systems require movement restrictions but disrupt sensorimotor experience, causing neuronal and behavioral alterations. We report the development of FreemoVR, a VR system for freely moving animals. We validate immersive VR for mice, flies, and zebrafish. FreemoVR allows instant, disruption-free environmental reconfigurations and interactions between real organisms and computer-controlled agents. Using the FreemoVR platform, we established a height-aversion assay in mice and studied visuomotor effects in Drosophila and zebrafish. Furthermore, by photorealistically mimicking zebrafish we discovered that effective social influence depends on a prospective leader balancing its internally preferred directional choice with social interaction. FreemoVR technology facilitates detailed investigations into neural function and behavior through the precise manipulation of sensorimotor feedback loops in unrestrained animals.

  4. Prey capture by freely swimming flagellates

    Science.gov (United States)

    Andersen, Anders; Dolger, Julia; Nielsen, Lasse Tor; Kiorboe, Thomas

    2017-11-01

    Flagellates are unicellular microswimmers that propel themselves using one or several beating flagella. Here, we explore the dependence of swimming kinematics and prey clearance rate on flagellar arrangement and determine optimal flagellar arrangements and essential trade-offs. To describe near-cell flows around freely swimming flagellates we consider a model in which the cell is represented by a no-slip sphere and each flagellum by a point force. For uniflagellates pulled by a single flagellum the model suggests that a long flagellum favors fast swimming, whereas high clearance rate is favored by a very short flagellum. For biflagellates with both a longitudinal and a transversal flagellum we explore the helical swimming kinematics and the prey capture sites. We compare our predictions with observations of swimming kinematics, prey capture, and flows around common marine flagellates. The Centre for Ocean Life is a VKR Centre of Excellence supported by the Villum Foundation.

  5. Machine learning challenges in Mars rover traverse science

    Science.gov (United States)

    Castano, R.; Judd, M.; Anderson, R. C.; Estlin, T.

    2003-01-01

    The successful implementation of machine learning in autonomous rover traverse science requires addressing challenges that range from the analytical technical realm, to the fuzzy, philosophical domain of entrenched belief systems within scientists and mission managers.

  6. APOLLO 17 TRAVERSE GRAVIMETER DATA V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains a table of readings from the Traverse Gravimeter Experiment performed during the Apollo 17 mission. The gravimeter, which recorded relative...

  7. SPS and PS Experiments Committee

    CERN Multimedia

    CERN. Geneva

    2004-01-01

    OPEN SESSION: 09:00 Status report of NA58 / COMPASS: A. Magnon 09:40 Status report of PS212 / DIRAC: L. Tausher 10:10 PS212 / DIRAC Addendum: L. Nemenov CLOSED SESSION on Tuesday, 27 April 2004 after the open session, Main Building, 6th floor conference room

  8. Diffusion processes in freely suspended smectic films

    Science.gov (United States)

    Śliwa, I.; Zakharov, A. V.

    2017-08-01

    A molecular model describing translational diffusion in freely suspended smectic films (FSSFs) in air is proposed. This model is based on the random walk theory and allows calculation of the translational diffusion coefficient (TDC) across smectic layers (along the director). All values necessary for calculating the TDC are obtained within the generalized mean-field model considering not only anisotropic interactions between nearest neighbors of molecules forming FSSFs, but also the stabilizing effect of the smectic/air interface. The spatial inhomogeneity of order parameters over the FSSF section, arising in this case, results in the fact that the surface tension at the smectic/air interface not only suppresses thermal fluctuations in surface layers, but also completely suppresses translational diffusion of molecules from the FSSF to air. The results of calculations of dimensional translational diffusion in the bulk of the FSSF formed by 5- n-alkyl-2-(4- n-(perfluoroalkyl-metyleneoxy))pentyl molecules during its thinning show that the TDC monotonically increases as the smectic film is thinned.

  9. Mechanisms of microbial traversal of the blood-brain barrier.

    Science.gov (United States)

    Kim, Kwang Sik

    2008-08-01

    Central nervous system (CNS) infections continue to be an important cause of morbidity and mortality. Microbial invasion and traversal of the blood-brain barrier is a prerequisite for CNS infections. Pathogens can cross the blood-brain barrier transcellularly, paracellularly and/or in infected phagocytes (the so-called Trojan-horse mechanism). Consequently, pathogens can cause blood-brain barrier dysfunction, including increased permeability, pleocytosis and encephalopathy. A more complete understanding of the microbial-host interactions that are involved in microbial traversal of the blood-brain barrier and the associated barrier dysfunction should help to develop new strategies to prevent CNS infections.

  10. Concurrent reflectance imaging and microdialysis in the freely behaving cat

    DEFF Research Database (Denmark)

    Poe, G R; Nitz, D A; Rector, D M

    1996-01-01

    We present a method to perform simultaneous microdialysis with light reflectance imaging of neural activity in a discrete brain region of the freely behaving animal. We applied this method to the dorsal hippocampus of freely behaving cats to (1) measure extracellular glutamate and reflectance var...

  11. Generalising tree traversals and tree transformations to DAGs

    DEFF Research Database (Denmark)

    Bahr, Patrick; Axelsson, Emil

    2017-01-01

    We present a recursion scheme based on attribute grammars that can be transparently applied to trees and acyclic graphs. Our recursion scheme allows the programmer to implement a tree traversal or a tree transformation and then apply it to compact graph representations of trees instead. The resul...

  12. Traversability analysis for a mine safety inspection robot

    CSIR Research Space (South Africa)

    Senekal, F

    2013-09-01

    Full Text Available A new fast algorithm for traversability analysis of an arbitrary three-dimensional point cloud is presented. The algorithm segments a three-dimensional point cloud into vertical sections; each of which is clustered into bins and further analysed...

  13. psRNATarget: a plant small RNA target analysis server.

    Science.gov (United States)

    Dai, Xinbin; Zhao, Patrick Xuechun

    2011-07-01

    Plant endogenous non-coding short small RNAs (20-24 nt), including microRNAs (miRNAs) and a subset of small interfering RNAs (ta-siRNAs), play important role in gene expression regulatory networks (GRNs). For example, many transcription factors and development-related genes have been reported as targets of these regulatory small RNAs. Although a number of miRNA target prediction algorithms and programs have been developed, most of them were designed for animal miRNAs which are significantly different from plant miRNAs in the target recognition process. These differences demand the development of separate plant miRNA (and ta-siRNA) target analysis tool(s). We present psRNATarget, a plant small RNA target analysis server, which features two important analysis functions: (i) reverse complementary matching between small RNA and target transcript using a proven scoring schema, and (ii) target-site accessibility evaluation by calculating unpaired energy (UPE) required to 'open' secondary structure around small RNA's target site on mRNA. The psRNATarget incorporates recent discoveries in plant miRNA target recognition, e.g. it distinguishes translational and post-transcriptional inhibition, and it reports the number of small RNA/target site pairs that may affect small RNA binding activity to target transcript. The psRNATarget server is designed for high-throughput analysis of next-generation data with an efficient distributed computing back-end pipeline that runs on a Linux cluster. The server front-end integrates three simplified user-friendly interfaces to accept user-submitted or preloaded small RNAs and transcript sequences; and outputs a comprehensive list of small RNA/target pairs along with the online tools for batch downloading, key word searching and results sorting. The psRNATarget server is freely available at http://plantgrn.noble.org/psRNATarget/.

  14. The PS locomotive runs again

    CERN Multimedia

    2001-01-01

    Over forty years ago, the PS train entered service to steer the magnets of the accelerator into place... ... a service that was resumed last Tuesday. Left to right: Raymond Brown (CERN), Claude Tholomier (D.B.S.), Marcel Genolin (CERN), Gérard Saumade (D.B.S.), Ingo Ruehl (CERN), Olivier Carlier (D.B.S.), Patrick Poisot (D.B.S.), Christian Recour (D.B.S.). It is more than ten years since people at CERN heard the rumbling of the old PS train's steel wheels. Last Tuesday, the locomotive came back into service to be tested. It is nothing like the monstrous steel engines still running on conventional railways -just a small electric battery-driven vehicle employed on installing the magnets for the PS accelerator more than 40 years ago. To do so, it used the tracks that run round the accelerator. In fact, it is the grandfather of the LEP monorail. After PS was commissioned in 1959, the little train was used more and more rarely. This is because magnets never break down, or hardly ever! In fact, the loc...

  15. The PS Booster hits 40

    CERN Multimedia

    Joannah Caborn Wengler

    2012-01-01

    Many accelerators’ "round" birthdays are being celebrated at CERN these days – the PS turned 50 in 2009, the SPS was 35 in 2011, and this year it's the turn of the PS Booster to mark its 40th anniversary. Originally designed to accelerate 1013 protons to 800 MeV, it has far exceeded its initial design performance over the years.   The PS Booster in the 1970s. Imagine the scene: a group of accelerator physicists staring expectantly at a monitor, when suddenly a shout of joy goes up as a signal flickers across the screen. Does that sound familiar? Well, turn the clock back 40 years (longer hair, wider trouser legs) and you have the situation at the PS Booster on 26 May 1972. On that day, beam was injected into the Booster for the first time. “It was a real buzz,” says Heribert Koziol, then Chairman of the Running-in Committee. “We were very happy – and also a little relieved – when the beam finally...

  16. Cooperative Three-Robot System for Traversing Steep Slopes

    Science.gov (United States)

    Stroupe, Ashley; Huntsberger, Terrance; Aghazarian, Hrand; Younse, Paulo; Garrett, Michael

    2009-01-01

    Teamed Robots for Exploration and Science in Steep Areas (TRESSA) is a system of three autonomous mobile robots that cooperate with each other to enable scientific exploration of steep terrain (slope angles up to 90 ). Originally intended for use in exploring steep slopes on Mars that are not accessible to lone wheeled robots (Mars Exploration Rovers), TRESSA and systems like TRESSA could also be used on Earth for performing rescues on steep slopes and for exploring steep slopes that are too remote or too dangerous to be explored by humans. TRESSA is modeled on safe human climbing of steep slopes, two key features of which are teamwork and safety tethers. Two of the autonomous robots, denoted Anchorbots, remain at the top of a slope; the third robot, denoted the Cliffbot, traverses the slope. The Cliffbot drives over the cliff edge supported by tethers, which are payed out from the Anchorbots (see figure). The Anchorbots autonomously control the tension in the tethers to counter the gravitational force on the Cliffbot. The tethers are payed out and reeled in as needed, keeping the body of the Cliffbot oriented approximately parallel to the local terrain surface and preventing wheel slip by controlling the speed of descent or ascent, thereby enabling the Cliffbot to drive freely up, down, or across the slope. Due to the interactive nature of the three-robot system, the robots must be very tightly coupled. To provide for this tight coupling, the TRESSA software architecture is built on a combination of (1) the multi-robot layered behavior-coordination architecture reported in "An Architecture for Controlling Multiple Robots" (NPO-30345), NASA Tech Briefs, Vol. 28, No. 10 (October 2004), page 65, and (2) the real-time control architecture reported in "Robot Electronics Architecture" (NPO-41784), NASA Tech Briefs, Vol. 32, No. 1 (January 2008), page 28. The combination architecture makes it possible to keep the three robots synchronized and coordinated, to use data

  17. Malaria Sporozoites Traverse Host Cells within Transient Vacuoles.

    Science.gov (United States)

    Risco-Castillo, Veronica; Topçu, Selma; Marinach, Carine; Manzoni, Giulia; Bigorgne, Amélie E; Briquet, Sylvie; Baudin, Xavier; Lebrun, Maryse; Dubremetz, Jean-François; Silvie, Olivier

    2015-11-11

    Plasmodium sporozoites are deposited in the host skin by Anopheles mosquitoes. The parasites migrate from the dermis to the liver, where they invade hepatocytes through a moving junction (MJ) to form a replicative parasitophorous vacuole (PV). Malaria sporozoites need to traverse cells during progression through host tissues, a process requiring parasite perforin-like protein 1 (PLP1). We find that sporozoites traverse cells inside transient vacuoles that precede PV formation. Sporozoites initially invade cells inside transient vacuoles by an active MJ-independent process that does not require vacuole membrane remodeling or release of parasite secretory organelles typically involved in invasion. Sporozoites use pH sensing and PLP1 to exit these vacuoles and avoid degradation by host lysosomes. Next, parasites enter the MJ-dependent PV, which has a different membrane composition, precluding lysosome fusion. The malaria parasite has thus evolved different strategies to evade host cell defense and establish an intracellular niche for replication.

  18. On Fusing Recursive Traversals of K-d Trees

    Energy Technology Data Exchange (ETDEWEB)

    Rajbhandari, Samyam; Kim, Jinsung; Krishnamoorthy, Sriram; Pouchet, Louis-Noel; Rastello, Fabrice; Harrison, Robert J.; Sadayappan, Ponnuswamy

    2016-03-17

    Loop fusion is a key program transformation for data locality optimization that is implemented in production compilers. But optimizing compilers currently cannot exploit fusion opportunities across a set of recursive tree traversal computations with producer-consumer relationships. In this paper, we develop a compile-time approach to dependence characterization and program transformation to enable fusion across recursively specified traversals over k-ary trees. We present the FuseT source-to-source code transformation framework to automatically generate fused composite recursive operators from an input program containing a sequence of primitive recursive operators. We use our framework to implement fused operators for MADNESS, Multiresolution Adaptive Numerical Environment for Scientific Simulation. We show that locality optimization through fusion can offer more than an order of magnitude performance improvement.

  19. CT-FC: more Comprehensive Traversal Focused Crawler

    Directory of Open Access Journals (Sweden)

    NFN Kuspriyanto

    2012-03-01

    Full Text Available In todays world, people depend more on the WWW information, including professionals who have to analyze the data according their domain to maintain and improve their business. A data analysis would require information that is comprehensive and relevant to their domain. Focused crawler as a topical based Web indexer agent is used to meet this applications information need. In order to increase the precision, focused crawler face the problem of low recall. The study on WWW hyperlink structure characteristics indicates that many Web documents are not strong connected but through co-citation & co-reference. Conventional focused crawler that uses forward crawling strategy could not visit the documents in these characteristics. This study proposes a more comprehensive traversal framework. As a proof, CT-FC (a focused crawler with the new traversal framework ran on DMOZ data that is representative to WWW characteristics. The results show that this strategy can increase the recall significantly.

  20. A visual display aid for planning rover traversals

    Science.gov (United States)

    Bernard, Herbert F.; Ellis, Stephen R.

    1992-01-01

    An interactive graphical planning system has been developed, which allows a human operator to design and check traversals (cross-country paths) for a planetary rover vehicle. The display provides the operator with necessary information about the terrain and indicates violations of operational or dynamic constraints on the rover. The operator can select different kinds of two-dimensional maps as well as a perspective view of the rover environment to plan the traversals. An experiment has been carried out to determine the ability of the operator to estimate the rover attitude in a large variety of situations. It turned out that the estimation error is highly dependent on the rover attitude itself. This result can be used to determine a vertical scale for the perspective representation of the terrain which avoids an underestimation of dangerous rover attitudes.

  1. Terrain traversability analysis methods for unmanned ground vehicles: A survey

    OpenAIRE

    Papadakis, Panagiotis

    2013-01-01

    International audience; Motion planning for unmanned ground vehicles (UGV) constitutes a domain of research where several disciplines meet, ranging from artificial intelligence and machine learning to robot perception and computer vision. In view of the plurality of related applications such as planetary exploration, search and rescue, agriculture, mining and off-road exploration, the aim of the present survey is to review the field of 3D terrain traversability analysis that is employed at a ...

  2. Traversable geometric dark energy wormholes constrained by astrophysical observations

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Deng [Nankai University, Theoretical Physics Division, Chern Institute of Mathematics, Tianjin (China); Meng, Xin-he [Nankai University, Department of Physics, Tianjin (China); Institute of Theoretical Physics, CAS, State Key Lab of Theoretical Physics, Beijing (China)

    2016-09-15

    In this paper, we introduce the astrophysical observations into the wormhole research. We investigate the evolution behavior of the dark energy equation of state parameter ω by constraining the dark energy model, so that we can determine in which stage of the universe wormholes can exist by using the condition ω < -1. As a concrete instance, we study the Ricci dark energy (RDE) traversable wormholes constrained by astrophysical observations. Particularly, we find from Fig. 5 of this work, when the effective equation of state parameter ω{sub X} < -1 (or z < 0.109), i.e., the null energy condition (NEC) is violated clearly, the wormholes will exist (open). Subsequently, six specific solutions of statically and spherically symmetric traversable wormhole supported by the RDE fluids are obtained. Except for the case of a constant redshift function, where the solution is not only asymptotically flat but also traversable, the five remaining solutions are all non-asymptotically flat, therefore, the exotic matter from the RDE fluids is spatially distributed in the vicinity of the throat. Furthermore, we analyze the physical characteristics and properties of the RDE traversable wormholes. It is worth noting that, using the astrophysical observations, we obtain the constraints on the parameters of the RDE model, explore the types of exotic RDE fluids in different stages of the universe, limit the number of available models for wormhole research, reduce theoretically the number of the wormholes corresponding to different parameters for the RDE model, and provide a clearer picture for wormhole investigations from the new perspective of observational cosmology. (orig.)

  3. Evaporation induced traversability of the Einstein--Rosen wormhole

    OpenAIRE

    Krasnikov, S.

    2005-01-01

    Suppose, the Universe comes into existence (as classical spacetime) already with an empty spherically symmetric macroscopic wormhole present in it. Classically the wormhole would evolve into a part of the Schwarzschild space and thus would not allow any signal to traverse it. I consider semiclassical corrections to that picture and build a model of an evaporating wormhole. The model is based on the assumption that the vacuum polarization and its backreaction on the geometry of the wormhole ar...

  4. Mapping, Navigation, and Learning for Off-Road Traversal

    DEFF Research Database (Denmark)

    Konolige, Kurt; Agrawal, Motilal; Blas, Morten Rufus

    2009-01-01

    The challenge in the DARPA Learning Applied to Ground Robots (LAGR) project is to autonomously navigate a small robot using stereo vision as the main sensor. During this project, we demonstrated a complete autonomous system for off-road navigation in unstructured environments, using stereo vision......, online terrain traversability learning, visual odometry, map registration, planning, and control. At the end of 3 years, the system we developed outperformed all nine other teams in final blind tests over previously unseen terrain....

  5. Decentralised and Privacy-Aware Learning of Traversal Time Models

    OpenAIRE

    Le Van, Thanh; Bellet, Aurélien; Ramon, Jan

    2017-01-01

    International audience; Estimating traversal time is an essential problem in urban computing. Traditional methods learn a predictive model from user traces collected in a central server, which potentially threatens the privacy of the users, and which may be hard to realize in an online setting where communication with large amounts of cars is needed. In this paper, we propose a new approach to solve these problems by proposing a a privacy-friendly algorithm requiring only local communication....

  6. Perfusion Imaging with a Freely Diffusible Hyperpolarized Contrast Agent

    OpenAIRE

    Grant, Aaron K.; Vinogradov, Elena; Wang, Xiaoen; Lenkinski, Robert E.; Alsop, David C.

    2011-01-01

    Contrast agents that can diffuse freely into or within tissue have numerous attractive features for perfusion imaging. Here we present preliminary data illustrating the suitability of hyperpolarized 13C labeled 2-methylpropan-2-ol (also known as dimethylethanol, tertiary butyl alcohol and tert-butanol) as a freely diffusible contrast agent for magnetic resonance perfusion imaging. Dynamic 13C images acquired in rat brain with a balanced steady-state free precession (bSSFP) sequence following ...

  7. Footprint traversal by adenosine-triphosphate-dependent chromatin remodeler motor

    Science.gov (United States)

    Garai, Ashok; Mani, Jesrael; Chowdhury, Debashish

    2012-04-01

    Adenosine-triphosphate (ATP)-dependent chromatin remodeling enzymes (CREs) are biomolecular motors in eukaryotic cells. These are driven by a chemical fuel, namely, ATP. CREs actively participate in many cellular processes that require accessibility of specific segments of DNA which are packaged as chromatin. The basic unit of chromatin is a nucleosome where 146 bp ˜ 50 nm of a double-stranded DNA (dsDNA) is wrapped around a spool formed by histone proteins. The helical path of histone-DNA contact on a nucleosome is also called “footprint.” We investigate the mechanism of footprint traversal by a CRE that translocates along the dsDNA. Our two-state model of a CRE captures effectively two distinct chemical (or conformational) states in the mechanochemical cycle of each ATP-dependent CRE. We calculate the mean time of traversal. Our predictions on the ATP dependence of the mean traversal time can be tested by carrying out in vitro experiments on mononucleosomes.

  8. Desert Research and Technology Studies (DRATS) Traverse Planning

    Science.gov (United States)

    Horz, Friedrich

    2012-01-01

    Slide 1] The Desert Research and Technology Studies (DRATS) include large scale field tests of manned lunar surface exploration systems; these tests are sponsored by the Director s Office of Integration (DOI) [sic, Directorate Integration Office (DIO)] within the Constellation Program and they include geological exploration objectives along well designed traverses. These traverses are designed by the Traverse Team, an ad hoc group of some 10 geologists form NASA and academia, as well as experts in mission operation who define the operational constraints applicable to specific simulation scenarios. [Slide 2] These DRATS/DOI tests focus on 1) the performance of major surface systems, such as rovers, mobile habitats, communication architecture, navigation tools, earth-moving equipment, unmanned reconnaissance robots etc. under realistic field conditions and 2) the development of operational concepts that integrate all of these systems into a single, optimized operation. The participation of science is currently concentrating on geological sciences, with the objective of developing suitable tools and documentation protocols to sample representative rocks for Earth return, and to generate some conceptual understanding of the ground support structure that will be needed for the real time science-support of a lunar surface crew. [Slide 3] Major surface systems exercised in the June 2008 analog tests at the Moses Lake site, WA. [Upper left] The Chariot Rover (developed at Johnson Space Center) is an unpressurized vehicle driven by fully suited crews. [Upper right] Mobile Habitat provided by the Jet Propulsion Laboratory. Chariot is the more nimble and mobile vehicle and the idea is to drive the habitat remotely to some rendezvous place where Chariot would catch up - after a lengthy traverse - at the end of the day. [Lower left] The K-10 remotely operated robot (provided by NASA Ames Research Center) conducting scientific/geologic reconnaissance of the prospective traverse

  9. Training Revising Based Traversability Analysis of Complex Terrains for Mobile Robot

    Directory of Open Access Journals (Sweden)

    Rui Song

    2014-05-01

    Full Text Available Traversability analysis is one of the core issues in the autonomous navigation for mobile robots to identify the accessible area by the information of sensors on mobile robots. This paper proposed a model to analyze the traversability of complex terrains based on rough sets and training revising. The model described the traversability for mobile robots by traversability cost. Through the experiment, the paper gets the conclusion that traversability analysis model based on rough sets and training revising can be used where terrain features are rich and complex, can effectively handle the unstructured environment, and can provide reliable and effective decision rules in the autonomous navigation for mobile robots.

  10. Scattering of electromagnetic waves by a traversable wormhole

    Directory of Open Access Journals (Sweden)

    B. Nasr Esfahani

    2005-09-01

    Full Text Available   Replacing the wormhole geometry with an equivalent medium using the perturbation theory of scattering and the Born approximation, we have calculated the differential scattering cross section of electromagnetic waves by a traversable wormhole. It is shown that scattering at long wavelenghts can essentially distinguish wormhole from ordinary scattering object. Some of the zeros of the scattering cross section are determined which can be used for estimating the radius of the throat of wormholes. The known result that in this kind of scattering the linear polarization remains unchanged is verified here.

  11. Conformally symmetric traversable wormholes in f( G) gravity

    Science.gov (United States)

    Sharif, M.; Fatima, H. Ismat

    2016-11-01

    We discuss non-static conformally symmetric traversable wormholes for spherically symmetric spacetime using the model f(G)=α Gn, where n>0 and α is an arbitrary constant. We investigate wormhole solutions by taking two types of shape function and found that physically realistic wormholes exist only for even values of n. We also check the validity of flare-out condition, required for wormhole construction, for the shape functions deduced from two types of equation of state. It is found that this condition is satisfied by these functions in all cases except phantom case with non-static conformal symmetry.

  12. ArcGIS Digitization of Apollo Surface Traverses

    Science.gov (United States)

    Petro, N. E.; Bleacher, J. E.; Gladdis, L. R.; Garry, W. B.; Lam, F.; Mest, S. C.

    2012-01-01

    The Apollo surface activities were documented in extraordinary detail, with every action performed by the astronauts while on the surface recorded either in photo, audio, film, or by written testimony [1]. The samples and in situ measurements the astronauts collected while on the lunar surface have shaped our understanding of the geologic history of the Moon, and the earliest history and evolution of the inner Solar System. As part of an ongoing LASERfunded effort, we are digitizing and georeferencing data from astronaut traverses and spatially associating them to available, co-registered remote sensing data. Here we introduce the products produced so far for Apollo 15, 16, and 17 missions.

  13. High-Performance Plastic Sled Design for Polar Traversing

    Science.gov (United States)

    2015-06-01

    PE sheet that survived two years of service for SPoT. All other specimens were made from new, unused HMW-PE from the same production run as sheets...12-12, “Field Support for GrIT.” The technical monitors were George Blaisdell, Chief Program Manager, NSF-PLR, U.S. Antarctic Program (USAP), and...Division of Polar Programs SPoT South Pole Traverse USAP U.S. Antarctic Program UV Ultraviolet ERDC TR-15-2 viii Unit Conversion Factors

  14. EDH 'Millionaire' in PS Division

    CERN Document Server

    2001-01-01

    Christmas cheer! Left to right: Gerard Lobeau receives a bottle of Champagne from Derek Mathieson and Jurgen De Jonghe in recognition of EDH's millionth document. At 14:33 on Monday 3 December a technician in PS division, Gerard Lobeau, unwittingly became part of an important event in the life of CERN's Electronic Document Handling system (EDH). While ordering some pieces of aluminum for one of the PS's 10Mhz RF cavities, he created EDH document number 1,000,000. To celebrate the event Derek Mathieson (EDH Project Leader) and Jurgen De Jonghe (Original EDH Project Leader) presented Mr Lobeau with a bottle of champagne. As with 93% of material requests, Mr Lobeau's order was delivered within 24 hours. 'I usually never win anything' said Mr Lobeau as he accepted his prize, 'I initially though there may have been a problem with EDH when the document number had so many zeros in it, and was then surprised to get a phone call from you a few minutes later.' The EDH team had been monitoring the EDH document number ...

  15. Lunar Surface Potential Increases during Terrestrial Bow Shock Traversals

    Science.gov (United States)

    Collier, Michael R.; Stubbs, Timothy J.; Hills, H. Kent; Halekas, Jasper; Farrell, William M.; Delory, Greg T.; Espley, Jared; Freeman, John W.; Vondrak, Richard R.; Kasper, Justin

    2009-01-01

    Since the Apollo era the electric potential of the Moon has been a subject of interest and debate. Deployed by three Apollo missions, Apollo 12, Apollo 14 and Apollo 15, the Suprathermal Ion Detector Experiment (SIDE) determined the sunlit lunar surface potential to be about +10 Volts using the energy spectra of lunar ionospheric thermal ions accelerated toward the Moon. We present an analysis of Apollo 14 SIDE "resonance" events that indicate the lunar surface potential increases when the Moon traverses the dawn bow shock. By analyzing Wind spacecraft crossings of the terrestrial bow shock at approximately this location and employing current balancing models of the lunar surface, we suggest causes for the increasing potential. Determining the origin of this phenomenon will improve our ability to predict the lunar surface potential in support of human exploration as well as provide models for the behavior of other airless bodies when they traverse similar features such as interplanetary shocks, both of which are goals of the NASA Lunar Science Institute's Dynamic Response of the Environment At the Moon (DREAM) team.

  16. Insects traversing grass-like vertical compliant beams

    Science.gov (United States)

    Li, Chen; Fearing, Ronald; Full, Robert

    2014-03-01

    Small running animals encounter many challenging terrains. These terrains can be filled with 3D, multi-component obstacles. Here, we study cockroaches (Blaberus discoidalis) moving through grass-like vertical compliant beams during escape. We created an apparatus to control and vary geometric parameters and mechanical properties of model grass including height, width, thickness, lateral and fore-aft spacings, angle, number of layers, stiffness, and damping. We observed a suite of novel locomotor behaviors not previously described on simpler 2D ground. When model grass height was >2 × body length and lateral spacing was animal primarily (probability P = 50%) rolled its body onto its side to rapidly (time t = 2.1 s) maneuver through the gaps between model grass. We developed a simple energy minimization model, and found that body roll reduces the energy barriers that the animal must overcome during traversal. We hypothesized that the animal's ellipsoidal body shape facilitated traversal. To test our hypothesis, we modified body shape by adding either a rectangular or an oval plate onto its dorsal surface, and found that P dropped by an order of magnitude and t more than doubled. Upon removal of either plate, both P and t recovered. Locomotor kinematics and geometry effectively coupled to terrain properties enables negotiation of 3D, multi-component obstacles, and provides inspiration for small robots to navigate such terrain with minimal sensing and control.

  17. Saccadic head and thorax movements in freely walking blowflies

    NARCIS (Netherlands)

    Blaj, G.; Hateren, J.H. van

    2004-01-01

    Visual information processing is adapted to the statistics of natural visual stimuli, and these statistics depend to a large extent on the movements of an animal itself. To investigate such movements in freely walking blowflies, we measured the orientation and position of their head and thorax, with

  18. NAT Traversal Capability and Keep-Alive Functionality with IPSec in IKEv2 Implementation

    OpenAIRE

    CHAMAN SINGH; K.L.Bansal

    2012-01-01

    Since IPv4 Private Networks are behind NAT (Network Address Translation) devices. So, to bypass the Binding Update and Binding Acknowledgment by NAT, we need to encapsulate it in UDP (User datagram Protocol) Packets. Hence, the Dual Stack Mobile IPv6 should support NAT Traversal and Detection. So for proper securing and fully functionality of NAT traversal, it should be IP Security Protected. Paper presents design and implementation of NAT traversal capability and keeps alive functionality wi...

  19. GPU accelerated tandem traversal of blocked bounding volume hierarchy collision detection for multibody dynamics

    DEFF Research Database (Denmark)

    Damkjær, Jesper; Erleben, Kenny

    2009-01-01

    hierarchies. Our approach makes it possible to perform non-convex object versus non-convex object collision on the GPU, using tandem traversals of bounding volume hierarchies. Prior work only supports single traversals on GPUs. We introduce a blocked hierarchy data structure, using imaginary nodes...... and a simultaneous descend in the tandem traversal. The data structure design and traversal are highly specialized for exploiting the parallel threads in the NVIDIA GPUs. As proof-of-concept we demonstrate a GPU implementation for a multibody dynamics simulation, showing an approximate speedup factor of up to 8...

  20. Magnetic tracking of eye position in freely behaving chickens

    Science.gov (United States)

    Schwarz, Jason S.; Sridharan, Devarajan; Knudsen, Eric I.

    2013-01-01

    Research on the visual system of non-primates, such as birds and rodents, is increasing. Evidence that neural responses can differ dramatically between head-immobilized and freely behaving animals underlines the importance of studying visual processing in ethologically relevant contexts. In order to systematically study visual responses in freely behaving animals, an unobtrusive system for monitoring eye-in-orbit position in real time is essential. We describe a novel system for monitoring eye position that utilizes a head-mounted magnetic displacement sensor coupled with an eye-implanted magnet. This system is small, lightweight, and offers high temporal and spatial resolution in real time. We use the system to demonstrate the stability of the eye and the stereotypy of eye position during two different behavioral tasks in chickens. This approach offers a viable alternative to search coil and optical eye tracking techniques for high resolution tracking of eye-in-orbit position in behaving animals. PMID:24312023

  1. Vibration transmission characteristics of the legs of freely standing honeybees

    DEFF Research Database (Denmark)

    Rohrseitz, Kristin; Kilpinen, Ole

    1997-01-01

    The leg vibrations of honeybees standing on a vibrating substrate were measured with laser Doppler vibrometry, both in freely standing bees and in bees attached to a holder. In both cases, no resonances were found. In the fixed bee preparation, the legs moved with approximately the same amplitude...... that the subgenual organ is sensitive mainly to vibrations in the direction of the long axis of the leg....

  2. Ps-atom scattering at low energies

    CERN Document Server

    Fabrikant, I I

    2015-01-01

    A pseudopotential for positronium-atom interaction, based on electron-atom and positron-atom phase shifts, is constructed, and the phase shifts for Ps-Kr and Ps-Ar scattering are calculated. This approach allows us to extend the Ps-atom cross sections, obtained previously in the impulse approximation [Phys. Rev. Lett. 112, 243201 (2014)], to energies below the Ps ionization threshold. Although experimental data are not available in this low-energy region, our results describe well the tendency of the measured cross sections to drop with decreasing velocity at $v<1$ a.u. Our results show that the effect of the Ps-atom van der Waals interaction is weak compared to the polarization interaction in electron-atom and positron-atom scattering. As a result, the Ps scattering length for both Ar and Kr is positive, and the Ramsauer-Townsend minimum is not observed for Ps scattering from these targets. This makes Ps scattering quite different from electron scattering in the low-energy region, in contrast to the inter...

  3. Enhanced personal protection at the PS

    CERN Multimedia

    Samuel Morier Genoud

    2013-01-01

    Pictures 03, 06, 07 08 : Pierre Ninin, deputy group leader of GS-ASE and responsible for the installation of the new PS complex safety system, in front of a new access control system.Pictures 10, 12 ,13 : View of Building 271, the future control centre of the new PS complex safety system.

  4. PS, SL and LHC Auditoria change names

    CERN Document Server

    2003-01-01

    Following the replacement of the PS, SL and LHC Divisions by the AB and AT Divisions, the Auditoria are also changing their names. PS Auditorium is renamed AB Meyrin SL Auditorium is renamed AB Prévessin LHC Auditorium is renamed AT

  5. Operational vibroseis system for long-distance traverses

    Science.gov (United States)

    Eisen, Olaf; Hofstede, Coen; Diez, Anja; Kristoffersen, Yngve; Lambrecht, Astrid; Mayer, Christoph; Blenkner, Rick; Hilmarsson, Sverrir

    2014-05-01

    This poster presents results and performance of an operational vibroseis system used in Antarctica on the Ekströmisen and its catchment area. The about 500 km long overland traverse covered very different surface regimes in the elevation range from sea level up to 1000 m in the austral season 2013/14. The presentation is the successful culmination of a six-year effort to develop an operational vibroseis system for Antarctica and Greenland. Over three weeks the campaign acquired: • 407 km of seismic profiles in total, thereof • 110 km in 6-fold resolution with 125 m shot spacing • 25 km in 3-fold resolution with 250 m shot spacing. The remaining distance was covered in single-fold with 750 m shot spacing. The traverse used a well-established 60 channel 1.5 km streamer and a new setup with a vibroseis Buggy "EnviroVibe" with Mattracks on a polyethylen sled. The sled had a hole in the center to lower the vibrator pad directly onto the snow surface. With this setup data production varied between 20 km/day for 6-fold and 40 km/day for single fold for a decent 9h day of measurements. The combination of Mattracks with the PE-sled was especially advantageous on hard and rough surfaces because of the flexibility of each and the relatively lose mounting by cargo straps and wooden blocks. Production speeds were limited by the snow streamer, which had an increasing damage rate of geophone groups for velocities above 6 km/h. The source system itself could easily accommodate transfer velocities of 15 km/h. In combination with the streamer winch mounted in front of the source on a separate freight sled the channel spacing could be reduced to fractions of the 25 m spacing interval by combining several sweeps at the same location, thus increasing spatial resolution. The vibrator source was operated with a 10-250 Hz sweep over 10 s with 80% of the peak force of 66 kN. On soft surfaces a setup-sweep was utilized. Preliminary data analysis shows that sea floor geomorphology

  6. Climbing Mt. Sharp: Maximizing Curiosity's Science Over Traversable Terrains

    Science.gov (United States)

    Fraeman, A. A.; Arvidson, R. E.; Bellutta, P.; Sletten, R. S.; Team, M.

    2013-12-01

    As Curiosity transitions from the plains of Gale Crater to the flanks of Mt. Sharp, the rover will begin to encounter material and terrains that could present greater mobility challenges. These challenges include the presence of significantly steeper slopes and large dunes that have the potential to embed the vehicle. Strategic path planning during this phase of the mission will therefore require carefully selecting a traversable route that is both time-efficient and that will provide access to the most scientifically rewarding targets. We consider possible solutions to this optimization problem by examining multiple orbital data sets in order to locate likely mobility hazards and to select potential science waypoints for future in situ investigation. High resolution HiRISE monochromatic images and digital elevation models show filled craters, rock fields, areas with slopes too steep for the rover to traverse, and other possible mobility obstacles on the northwest flank of Mt. Sharp. Using this context, we review accessibility to scientific targets on Mt. Sharp that have been previously discussed in landing site workshop presentations and peer-reviewed publications. Additionally, we identify new targets using detailed geologic maps combined with oversampled CRISM observations that provide mineralogical information at unprecedented high spatial resolutions (up to 6 m/pixel). For example, the spatially sharpened CRISM spectral data show a localized hematite deposit that is associated with the upper-most stratum of a ridge which is located ~3km from the rover's entry point to Mt. Sharp. This deposit may represent a previously habitable environment and is therefore a high priority target for in situ investigation. In order to study the hematite and also to eventually access the phyllosilicate-bearing trough that is located directly behind the ridge, Curiosity will have to cross this ridge, but the ridge edges are often defined by regions with slopes that are too steep

  7. Anechoic chamber qualification: traverse method, inverse square law analysis method, and nature of test signal.

    Science.gov (United States)

    Cunefare, Kenneth A; Biesel, Van B; Tran, John; Rye, Ryan; Graf, Aaron; Holdhusen, Mark; Albanese, Anne-Marie

    2003-02-01

    Qualification of anechoic chambers is intended to demonstrate that the chamber supports the intended free-field environment within some permissible tolerance bounds. Key qualification issues include the method used to obtain traverse data, the analysis method for the data, and the use of pure tone or broadband noise as the chamber excitation signal. This paper evaluates the relative merits of continuous versus discrete traverses, of fixed versus optimal reference analysis of the traverse data, and of the use of pure tone versus broadband signals. The current practice of using widely space discrete sampling along a traverse is shown to inadequately sample the complexity of the sound field extant with pure tone traverses, but is suitable for broadband traverses. Continuous traverses, with spatial resolution on the order of 15% of the wavelength at the frequency of interest, are shown to be necessary to fully resolve the spatial complexity of pure tone qualifications. The use of an optimal reference method for computing the deviations from inverse square law is shown to significantly improve the apparent performance of the chamber for pure tone qualifications. Finally, the use of broadband noise as the test signal, as compared to pure tone traverses over the same span, is demonstrated to be a marginal indicator of chamber performance.

  8. A Distributed Election and Spanning Tree Algorithm Based on Depth First Search Traversals

    DEFF Research Database (Denmark)

    Skyum, Sven

    The existence of an effective distributed traversal algorithm for a class of graphs has proven useful in connection with election problems for those classes. In this paper we show how a general traversal algorithm, such as depth first search, can be turned into an effective election algorithm using...... modular techniques. The presented method also constructs a spanning tree for the graph....

  9. Time for pulse traversal through slabs of dispersive and negative ($\\epsilon$, $\\mu$) materials

    CERN Document Server

    Nanda, Lipsa

    2007-01-01

    The traversal times for an electromagnetic pulse traversing a slab of dispersive and dissipative material with negative dielectric permittivity ($\\epsilon$) and magnetic permeability ($\\mu$) have been calculated by using the average flow of electromagnetic energy in the medium. The effects of bandwidth of the pulse and dissipation in the medium have been investigated. While both large bandwidth and large dissipation have similar effects in smoothening out the resonant features that appear due to Fabry-P\\'{e}rot resonances, large dissipation can result in very small or even negative traversal times near the resonant frequencies. We have also investigated the traversal times and Wigner delay times for obliquely incident pulses and evanescent pulses. The coupling to slab plasmon polariton modes in frequency ranges with negative $\\epsilon$ or $\\mu$ is shown to result in large traversal times at the resonant conditions. We also find that the group velocity mainly contributes to the delay times for pulse propagatin...

  10. TiPs: a database of therapeutic targets in pathogens and associated tools.

    KAUST Repository

    Lepore, Rosalba

    2013-05-21

    MOTIVATION: The need for new drugs and new targets is particularly compelling in an era that is witnessing an alarming increase of drug resistance in human pathogens. The identification of new targets of known drugs is a promising approach, which has proven successful in several cases. Here, we describe a database that includes information on 5153 putative drug-target pairs for 150 human pathogens derived from available drug-target crystallographic complexes. AVAILABILITY AND IMPLEMENTATION: The TiPs database is freely available at http://biocomputing.it/tips. CONTACT: anna.tramontano@uniroma1.it or allegra.via@uniroma1.it.

  11. Perfusion imaging with a freely diffusible hyperpolarized contrast agent.

    Science.gov (United States)

    Grant, Aaron K; Vinogradov, Elena; Wang, Xiaoen; Lenkinski, Robert E; Alsop, David C

    2011-09-01

    Contrast agents that can diffuse freely into or within tissue have numerous attractive features for perfusion imaging. Here we present preliminary data illustrating the suitability of hyperpolarized (13)C labeled 2-methylpropan-2-ol (also known as dimethylethanol, tertiary butyl alcohol and tert-butanol) as a freely diffusible contrast agent for magnetic resonance perfusion imaging. Dynamic (13)C images acquired in rat brain with a balanced steady-state free precession sequence following administration of hyperpolarized 2-methylpropan-2-ol show that this agent can be imaged with 2-4 s temporal resolution, 2 mm slice thickness, and 700 μm in-plane resolution while retaining adequate signal-to-noise ratio. (13)C relaxation measurements on 2-methylpropan-2-ol in blood at 9.4 T yield T(1) = 46 ± 4s and T(2) = 0.55 ± 0.03 s. In the rat brain at 4.7 T, analysis of the temporal dynamics of the balanced steady-state free precession image intensity in tissue and venous blood indicate that 2-methylpropan-2-ol has a T(2) of roughly 2-4s and a T(1) of 43 ± 24 s. In addition, the images indicate that 2-methylpropan-2-ol is freely diffusible in brain and hence has a long residence time in tissue; this in turn makes it possible to image the agent continuously for tens of seconds. These characteristics show that 2-methylpropan-2-ol is a promising agent for robust and quantitative perfusion imaging in the brain and body. Copyright © 2011 Wiley-Liss, Inc.

  12. Terradynamically streamlined shapes in animals and robots enhance traversability through densely cluttered terrain.

    Science.gov (United States)

    Li, Chen; Pullin, Andrew O; Haldane, Duncan W; Lam, Han K; Fearing, Ronald S; Full, Robert J

    2015-06-22

    Many animals, modern aircraft, and underwater vehicles use fusiform, streamlined body shapes that reduce fluid dynamic drag to achieve fast and effective locomotion in air and water. Similarly, numerous small terrestrial animals move through cluttered terrain where three-dimensional, multi-component obstacles like grass, shrubs, vines, and leaf litter also resist motion, but it is unknown whether their body shape plays a major role in traversal. Few ground vehicles or terrestrial robots have used body shape to more effectively traverse environments such as cluttered terrain. Here, we challenged forest-floor-dwelling discoid cockroaches (Blaberus discoidalis) possessing a thin, rounded body to traverse tall, narrowly spaced, vertical, grass-like compliant beams. Animals displayed high traversal performance (79 ± 12% probability and 3.4 ± 0.7 s time). Although we observed diverse obstacle traversal strategies, cockroaches primarily (48 ± 9% probability) used a novel roll maneuver, a form of natural parkour, allowing them to rapidly traverse obstacle gaps narrower than half their body width (2.0 ± 0.5 s traversal time). Reduction of body roundness by addition of artificial shells nearly inhibited roll maneuvers and decreased traversal performance. Inspired by this discovery, we added a thin, rounded exoskeletal shell to a legged robot with a nearly cuboidal body, common to many existing terrestrial robots. Without adding sensory feedback or changing the open-loop control, the rounded shell enabled the robot to traverse beam obstacles with gaps narrower than shell width via body roll. Such terradynamically 'streamlined' shapes can reduce terrain resistance and enhance traversability by assisting effective body reorientation via distributed mechanical feedback. Our findings highlight the need to consider body shape to improve robot mobility in real-world terrain often filled with clutter, and to develop better locomotor-ground contact models to understand

  13. Humidity distribution affected by freely exposed water surfaces

    DEFF Research Database (Denmark)

    Hygum, Morten Arnfeldt; Popok, Vladimir

    2014-01-01

    Accurate models for the water vapor flux at a water-air interface are required in various scientific, reliability and civil engineering aspects. Here, a study of humidity distribution in a container with air and freely exposed water is presented. A model predicting a spatial distribution and time...... evolution of relative humidity based on statistical rate theory and computational fluid dynamics is developed. In our approach we use short-term steady-state steps to simulate the slowly evolving evaporation in the system. Experiments demonstrate considerably good agreement with the computer modeling...

  14. Cyclothiazide induces seizure behavior in freely moving rats

    OpenAIRE

    Kong, Shuzhen; Qian, Binbin; Liu, Jianhui; Fan, Mingxin; Chen, Gong; Wang, Yun

    2010-01-01

    We have previously demonstrated that cyclothiazide (CTZ) is a potent convulsant drug inducing robust epileptiform activity in hippocampal neurons both in vitro and in vivo. Here we further establish an animal model for CTZ-induced behavioral seizures in freely moving rats. Microinjection of CTZ into left ventricle dose-dependently induced robust seizure behaviors within three hours after administration. At doses of 0.75 μmol, CTZ induced Racine score IV-V seizure behaviors in 71% (n=14) of th...

  15. Freely chosen cadence during a covert manipulation of ambient temperature.

    Science.gov (United States)

    Hartley, Geoffrey L; Cheung, Stephen S

    2013-01-01

    The present study investigated relationships between changes in power output (PO) to torque (TOR) or freely chosen cadence (FCC) during thermal loading. Twenty participants cycled at a constant rating of perceived exertion while ambient temperature (Ta) was covertly manipulated at 20-min intervals of 20 °C, 35 °C, and 20 °C. The magnitude responses of PO, FCC and TOR were analyzed using repeated-measures ANOVA, while the temporal correlations were analyzed using Auto-Regressive Integrated Moving Averages (ARIMA). Increases in Ta caused significant thermal strain (p stressors.

  16. On the crystallization behavior of syndiotactic-b-atactic polystyrene stereodiblock copolymers, atactic/syndiotactic polystyrene blends, and aPS/sPS blends modified with sPS-b-aPS

    Energy Technology Data Exchange (ETDEWEB)

    Annunziata, Liana, E-mail: liana.annunziatta@univ-rennes1.fr [Organométalliques et Catalyse, UMR 6226 Sciences Chimiques CNRS, Université de Rennes 1, Campus de Beaulieu, F-35042 Rennes Cedex (France); Monasse, Bernard, E-mail: bernard.monasse@mines-paristech.fr [Mines-ParisTech, CEMEF, Centre de Mise en Forme des Matériaux, UMR CNRS 7635, Sophia Antipolis (France); Rizzo, Paola; Guerra, Gaetano [Dipartimento di Chimica e Biologia, Università degli studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano, SA (Italy); Duc, Michel [Total Petrochemicals Research Feluy, Zone Industrielle Feluy C, B-7181 Seneffe (Belgium); Carpentier, Jean-François, E-mail: jean-francois.carpentier@univ-rennes1.fr [Organométalliques et Catalyse, UMR 6226 Sciences Chimiques CNRS, Université de Rennes 1, Campus de Beaulieu, F-35042 Rennes Cedex (France)

    2013-09-16

    Crystallization and morphological features of syndiotactic-b-atactic polystyrene stereodiblock copolymers (sPS-b-aPS), atactic/syndiotactic polystyrene blends (aPS/sPS), and aPS/sPS blends modified with sPS-b-aPS, with different compositions in aPS and sPS, have been investigated using differential scanning calorimetry (DSC), polarized light optical microscopy (POM) and wide angle X-ray diffraction (WAXRD) techniques. For comparative purposes, the properties of parent pristine sPS samples were also studied. WAXRD analyses revealed for all the samples, independently from their composition (aPS/sPS ratio) and structure (blends, block copolymers, blends modified with block copolymers), the same polymorphic β form of sPS. The molecular weight of aPS and sPS showed opposite effects on the crystallization of 50:50 aPS/sPS blends: the lower the molecular weight of aPS, the slower the crystallization while the lower the molecular weight of sPS, the faster the crystallization. DSC studies performed under both isothermal and non-isothermal conditions, independently confirmed by POM studies, led to a clear trend for the crystallization rate at a given sPS/aPS ratio (ca. 50:50 and 20:80): sPS homopolymers > sPS-b-aPS block copolymers ∼sPS/aPS blends modified with sPS-b-aPS copolymers > sPS/aPS blends. Interestingly, sPS-b-aPS block copolymers not only crystallized faster than blends, but also affected positively the crystallization behavior of blends. At 50:50 sPS/aPS ratio, blends (Blend-2), block copolymers (Cop-1) and blends modified with block copolymers (Blend-2-mod) crystallized via spherulitic crystalline growth controlled by an interfacial process. In all cases, an instantaneous nucleation was observed. The density of nuclei in block copolymers (160,000−190,000 nuclei mm{sup −3}) was always higher than that in blends and modified blends (30,000−60,000 nuclei mm{sup −3}), even for quite different sPS/aPS ratio. At 20:80 sPS/aPS ratio, the block copolymers

  17. Ps 22 in Gospels’ interpretation of Passion

    Directory of Open Access Journals (Sweden)

    Sylwester Jędrzejewski

    2012-09-01

    Full Text Available Ps 22 is a piece of artistically high poetry, clear images and metaphors, historical and prophetic references. The conviction of biblical scholars that the New Testament writers has recognized in Ps 22 prophetic witness of passion, accompanies the Church from its beginnings. The words of Jesus on the cross, taken from Ps 22: 2, have a character of lamentable re-symbolization of the prayer of Israel. These words establish a theological answer in the form of suitable credo as well. Dramatic question “why?” is connected with a proclamation and identification “My God”. The personal experience of oppression and death is included by Jesus in the history of his nation and in the experience of God. Ps 22 in the Gospels’ passion context becomes a proclamation form of prayer and a very personal, expressed in such dramatic circumstances confession of the faith.

  18. Self-Supervised Learning of Terrain Traversability from Proprioceptive Sensors

    Science.gov (United States)

    Bajracharya, Max; Howard, Andrew B.; Matthies, Larry H.

    2009-01-01

    Robust and reliable autonomous navigation in unstructured, off-road terrain is a critical element in making unmanned ground vehicles a reality. Existing approaches tend to rely on evaluating the traversability of terrain based on fixed parameters obtained via testing in specific environments. This results in a system that handles the terrain well that it trained in, but is unable to process terrain outside its test parameters. An adaptive system does not take the place of training, but supplements it. Whereas training imprints certain environments, an adaptive system would imprint terrain elements and the interactions amongst them, and allow the vehicle to build a map of local elements using proprioceptive sensors. Such sensors can include velocity, wheel slippage, bumper hits, and accelerometers. Data obtained by the sensors can be compared to observations from ranging sensors such as cameras and LADAR (laser detection and ranging) in order to adapt to any kind of terrain. In this way, it could sample its surroundings not only to create a map of clear space, but also of what kind of space it is and its composition. By having a set of building blocks consisting of terrain features, a vehicle can adapt to terrain that it has never seen before, and thus be robust to a changing environment. New observations could be added to its library, enabling it to infer terrain types that it wasn't trained on. This would be very useful in alien environments, where many of the physical features are known, but some are not. For example, a seemingly flat, hard plain could actually be soft sand, and the vehicle would sense the sand and avoid it automatically.

  19. Acceleration of Sparse Matrix-Vector Multiplication by Region Traversal

    Directory of Open Access Journals (Sweden)

    I. Šimeček

    2008-01-01

    Full Text Available Sparse matrix-vector multiplication (shortly SpM×V is one of most common subroutines in numerical linear algebra. The problem is that the memory access patterns during SpM×V are irregular, and utilization of the cache can suffer from low spatial or temporal locality. Approaches to improve the performance of SpM×V are based on matrix reordering and register blocking. These matrix transformations are designed to handle randomly occurring dense blocks in a sparse matrix. The efficiency of these transformations depends strongly on the presence of suitable blocks. The overhead of reorganization of a matrix from one format to another is often of the order of tens of executions ofSpM×V. For this reason, such a reorganization pays off only if the same matrix A is multiplied by multiple different vectors, e.g., in iterative linear solvers.This paper introduces an unusual approach to accelerate SpM×V. This approach can be combined with other acceleration approaches andconsists of three steps:1 dividing matrix A into non-empty regions,2 choosing an efficient way to traverse these regions (in other words, choosing an efficient ordering of partial multiplications,3 choosing the optimal type of storage for each region.All these three steps are tightly coupled. The first step divides the whole matrix into smaller parts (regions that can fit in the cache. The second step improves the locality during multiplication due to better utilization of distant references. The last step maximizes the machine computation performance of the partial multiplication for each region.In this paper, we describe aspects of these 3 steps in more detail (including fast and time-inexpensive algorithms for all steps. Ourmeasurements prove that our approach gives a significant speedup for almost all matrices arising from various technical areas.

  20. Yasp for LEIR to PS injection

    CERN Document Server

    Kain, V; Bartosik, H; Huschauer, A; Jacquet, D; Nicosia, D; Pasinelli, S; Wenninger, J

    2017-01-01

    The steering program YASP was introduced in the LEIRinjection as well as the extraction lines in 2016 to correctthe trajectories with well-known model based correctionalgorithms such as MICADO or SVD. In addition a YASPconfiguration was prepared to correct the extraction linetogether with the first turn of the PS. In this way the injectionoscillations can be corrected while keeping the trajectoryreasonable in the PS injection line.

  1. PS overcomes two serious magnet failures

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Two magnets and a bus bar connection in the PS were found to be faulty during high-voltage tests at the end of the accelerator shutdown. A five-week repair schedule was quickly devised. A team of mechanics, technicians and engineers worked at full speed to replace the faulty magnets, succeeding in limiting the delay of the accelerators' spring start-up to two weeks. Here we see the PS magnet string awaiting the replacement no. 6 magnet.

  2. Enhanced Central System of the Traversing Rod for High-Performance Rotor Spinning Machines

    Directory of Open Access Journals (Sweden)

    Valtera Jan

    2017-03-01

    Full Text Available The paper deals with the improvement of central traversing system on rotor spinning machines, where rectilinear motion with variable stroke is used. A new system of traversing rod with implemented set of magnetic-mechanical energy accumulators is described. Mathematical model of this system is analysed in the MSC. Software Adams/View and verified by an experimental measurement on a real-length testing rig. Analysis results prove the enhancement of devised traversing system, where the overall dynamic force is reduced considerably. At the same time, the precision of the traversing movement over the machine length is increased. This enables to increase machine operating speed while satisfying both the maximal tensile strength of the traversing rod and also output bobbin size standards. The usage of the developed mathematical model for determination of the optimal number and distribution of accumulators over the traversing rod of optional parameters is proved. The potential of the devised system for high-performance rotor spinning machines with longer traversing rod is also discussed.

  3. Exhaust Emission Traverse Investigation of a JT3D-1 Turbofan Engine.

    Science.gov (United States)

    1979-06-01

    12 Points 4 Area Weighted From Traverse Maps 3 Traverse Emission Indices And Efficiencies 5 I P V S —~~~~~~~~ I r ~~~--i~i...NOTE: NUMBERS fl4D1CATE THE ILLUSTRATION - IN PARTS PER MILU FIGURE 4. CO ~ (ISSI0~ TRAVERSE MAP—2...i-;~~. 16 El ~A T E n W I T H I N noN ARF : V AL U E S 41L LION. 79— 1 f l_ e r, 11 U - p

  4. Low energy o-Ps-o-Ps elastic scattering using a simple model

    Energy Technology Data Exchange (ETDEWEB)

    Himanshu, Sharma [Veer Kunwar Singh Univ., Dept. of Physics, Bihar (India); Kiran, Kumari [R N College, P. G. Dept. of Physics, Bihar (India); Sumana, Chakraborty [Indian Association for the Cultivation of Science, Dept. of Theoretical Physics (India)

    2009-06-15

    A simple model is employed to investigate o-Ps-o-Ps (positronium-positronium) scattering at low energies. This model contains the effect of exchange explicitly and a model long range potential in the framework of static-exchange model. These two physical features are of key importance in Ps-Ps (atom-atom) scattering system. S-wave triplet-triplet and singlet-singlet scattering lengths and corresponding phase shifts up to the incident momentum k = 0.5 a.u. are in excellent agreement with those yielded by most elaborate and theoretically sound predictions. (authors)

  5. Autonomous head-mounted electrophysiology systems for freely behaving primates.

    Science.gov (United States)

    Gilja, Vikash; Chestek, Cindy A; Nuyujukian, Paul; Foster, Justin; Shenoy, Krishna V

    2010-10-01

    Recent technological advances have led to new light-weight battery-operated systems for electrophysiology. Such systems are head mounted, run for days without experimenter intervention, and can record and stimulate from single or multiple electrodes implanted in a freely behaving primate. Here we discuss existing systems, studies that use them, and how they can augment traditional, physically restrained, 'in-rig' electrophysiology. With existing technical capabilities, these systems can acquire multiple signal classes, such as spikes, local field potential, and electromyography signals, and can stimulate based on real-time processing of recorded signals. Moving forward, this class of technologies, along with advances in neural signal processing and behavioral monitoring, have the potential to dramatically expand the scope and scale of electrophysiological studies. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. The near wake of a freely flying European starling

    Science.gov (United States)

    Kirchhefer, Adam J.; Kopp, Gregory A.; Gurka, Roi

    2013-05-01

    The wake of a freely flying European starling (Sturnus vulgaris) has been measured using high speed, time-resolved, particle image velocimetry, simultaneously with high speed cameras which imaged the bird. These have been used to generate vector maps that can be associated with the bird's location and wing configuration in the wind tunnel. Time series of measurements have been expressed as composite wake plots which depict segments of the wing beat cycle for various spanwise locations in the wake. Measurements indicate that downwash is not produced during the upstroke, suggesting that the upstroke does not generate lift. As well, the wake velocities imply the presence of streamwise vortical structures, in addition to tip vortices. These two characteristics indicate similarities between the wake of a bird and the wake of a bat, which may be general features of the wakes of flapping wings.

  7. Chronic detachable headphones for acoustic stimulation in freely moving animals.

    Science.gov (United States)

    Nodal, Fernando R; Keating, Peter; King, Andrew J

    2010-05-30

    A growing number of studies of auditory processing are being carried out in awake, behaving animals, creating a need for precisely controlled sound delivery without restricting head movements. We have designed a system for closed-field stimulus presentation in freely moving ferrets, which comprises lightweight, adjustable headphones that can be consistently positioned over the ears via a small, skull-mounted implant. The invasiveness of the implant was minimized by simplifying its construction and using dental adhesive only for attaching it to the skull, thereby reducing the surgery required and avoiding the use of screws or other anchoring devices. Attaching the headphones to a chronic implant also reduced the amount of contact they had with the head and ears, increasing the willingness of the animals to wear them. We validated sound stimulation via the headphones in ferrets trained previously in a free-field task to localize stimuli presented from one of two loudspeakers. Noise bursts were delivered binaurally over the headphones and interaural level differences (ILDs) were introduced to allow the sound to be lateralized. Animals rapidly transferred from the free-field task to indicate the perceived location of the stimulus presented over headphones. They showed near perfect lateralization with a 5 dB ILD, matching the scores achieved in the free-field task. As expected, the ferrets' performance declined when the ILD was reduced in value. This closed-field system can easily be adapted for use in other species, and provides a reliable means of presenting closed-field stimuli whilst monitoring behavioral responses in freely moving animals. (c) 2010 Elsevier B.V. All rights reserved.

  8. Rapid Traversability Assessment in 2.5D Grid-based Map on Rough Terrain

    Directory of Open Access Journals (Sweden)

    Yi Huang

    2008-11-01

    Full Text Available This paper presents a rapid traversability assessment approach based on an extended 2.5D grid-based representaion of the rough terrain. Stereo vision system is used to perceive the environment surrounding robot. Conventional 2D, 3D and other 2.5D grid maps determine the traversability indices of the grids directly from the sensor feedback, while our approach attempts to address the indices of terrain from multiple grids instead. By analyzing the properties of multiple grids that the robot is to traverse, passable grids are distinguished, which also takes the robot's size into account. Fuzzy logic framework is applied to extract traversabiltiy indices from the terrain characteristics. A soccer robot equipped with a stereo vision system is adopted for experiments. The results show that our map is capable of speeding the process of traversability assessment and providing an autonomous mobile robot with a appropriate representation of 3D uneven terrain profile.

  9. Effects of an Arctic Ocean Ski Traverse on the Protective Capabilities of Expedition Footwear

    National Research Council Canada - National Science Library

    Endrusick, Thomas; Frykman, Peter; O'Brien, Catherine; Giblo, Joseph

    2005-01-01

    A traverse of the Arctic Ocean during a 2000-km unsupported ski expedition provided an opportunity to assess the impact of an extreme cold environment on the protective capabilities of a specialized footwear system (FS...

  10. Vision-Based Real-Time Traversable Region Detection for Mobile Robot in the Outdoors.

    Science.gov (United States)

    Deng, Fucheng; Zhu, Xiaorui; He, Chao

    2017-09-13

    Environment perception is essential for autonomous mobile robots in human-robot coexisting outdoor environments. One of the important tasks for such intelligent robots is to autonomously detect the traversable region in an unstructured 3D real world. The main drawback of most existing methods is that of high computational complexity. Hence, this paper proposes a binocular vision-based, real-time solution for detecting traversable region in the outdoors. In the proposed method, an appearance model based on multivariate Gaussian is quickly constructed from a sample region in the left image adaptively determined by the vanishing point and dominant borders. Then, a fast, self-supervised segmentation scheme is proposed to classify the traversable and non-traversable regions. The proposed method is evaluated on public datasets as well as a real mobile robot. Implementation on the mobile robot has shown its ability in the real-time navigation applications.

  11. LS1 Report: PS beams are back!

    CERN Multimedia

    Katarina Anthony & Anaïs Schaeffer

    2014-01-01

    For the first time in over 15 months, there are beams back in the PS. Making their first tour of the accelerator today, 20 June, their injection marks the end of weeks of cold checkouts and hardware commissioning in the PS.   The CERN Control Centre (CCC) is back in business: people gather to restart the LHC injectors, today the PS. Since hardware commissioning was wrapped up on 23 May, the Operations Group (BE-OP) has been conducting cold checkouts on the PS. This involves switching on all of the machine's systems, verifying that they respond to commands by OP and ensuring they are calibrated to beam timings. "These verifications were done, in part, during the hardware commissioning dry runs," says Rende Steerenberg, PS section leader. "But the cold checkouts are on a much larger scale, as we act as if there is beam in the whole machine. We placed a full load on the controls system, cooling, networks, etc. in order to setup the accelerator in the most realis...

  12. Self Sustained Traversable Wormholes Induced by Gravity’s Rainbow and Noncommutative Geometry

    Directory of Open Access Journals (Sweden)

    Garattini Remo

    2013-09-01

    Full Text Available We compare the effects of Noncommutative Geometry and Gravity’s Rainbow on traversable wormholes which are sustained by their own gravitational quantum fluctuations. Fixing the geometry on a well tested model, we find that the final result shows that the wormhole is of the Planckian size. This means that the traversability of the wormhole is in principle, but not in practice.

  13. Dynamic traversal of high bumps and large gaps by a small legged robot

    Science.gov (United States)

    Gart, Sean; Winey, Nastasia; de La Tijera Obert, Rafael; Li, Chen

    Small animals encounter and negotiate diverse obstacles comparable in size or larger than themselves. In recent experiments, we found that cockroaches can dynamically traverse bumps up to 4 times hip height and gaps up to 1 body length. To better understand the physics that governs these locomotor transitions, we studied a small six-legged robot negotiating high bumps and large gaps and compared it to animal observations. We found that the robot was able to traverse bumps as large as 1 hip height and gaps as wide as 0.5 body length. For the bump, the robot often climbed over to traverse when initial body yaw was small, but was often deflected laterally and failed to traverse when initial body yaw was large. A simple locomotion energy landscape model explained these observations. For the gap, traversal probability decreased with gap width, which was well explained by a simple Lagrangian model of a forward-moving rigid body falling over the gap edge. For both the bump and the gap, animal performance far exceeded that of the robot, likely due to their relatively higher running speeds and larger rotational oscillations prior to and during obstacle traversal. Differences between animal and robot obstacle negotiation behaviors revealed that animals used active strategies to overcome potential energy barriers.

  14. Traversal Caches: A Framework for FPGA Acceleration of Pointer Data Structures

    Directory of Open Access Journals (Sweden)

    James Coole

    2010-01-01

    Full Text Available Field-programmable gate arrays (FPGAs and other reconfigurable computing (RC devices have been widely shown to have numerous advantages including order of magnitude performance and power improvements compared to microprocessors for some applications. Unfortunately, FPGA usage has largely been limited to applications exhibiting sequential memory access patterns, thereby prohibiting acceleration of important applications with irregular patterns (e.g., pointer-based data structures. In this paper, we present a design pattern for RC application development that serializes irregular data structure traversals online into a traversal cache, which allows the corresponding data to be efficiently streamed to the FPGA. The paper presents a generalized framework that benefits applications with repeated traversals, which we show can achieve between 7x and 29x speedup over pointer-based software. For applications without strictly repeated traversals, we present application-specialized extensions that benefit applications with highly similar traversals by exploiting similarity to improve memory bandwidth and execute multiple traversals in parallel. We show that these extensions can achieve a speedup between 11x and 70x on a Virtex4 LX100 for Barnes-Hut n-body simulation.

  15. PS overcomes two serious magnet failures

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Two magnets and a bus bar connection in the PS were found to be faulty during high-voltage tests at the end of the accelerator shutdown. A five-week repair schedule was quickly devised. A team of mechanics, technicians and engineers worked at full speed to replace the faulty magnets, succeeding in limiting the delay of the accelerators' spring start-up to two weeks. These pictures show one of the magnets (no. 19) on the PS locomotive brought back into service for the removal and replacement operations.

  16. Antarctic Exploration Parallels for Future Human Planetary Exploration: The Role and Utility of Long Range, Long Duration Traverses

    Science.gov (United States)

    Hoffman, Stephen J. (Editor); Voels, Stephen A. (Editor)

    2012-01-01

    Topics covered include: Antarctic Exploration Parallels for Future Human Planetary Exploration: Science Operations Lessons Learned, Planning, and Equipment Capabilities for Long Range, Long Duration Traverses; Parallels Between Antarctic Travel in 1950 and Planetary Travel in 2050 (to Accompany Notes on "The Norwegian British-Swedish Antarctic Expedition 1949-52"); My IGY in Antarctica; Short Trips and a Traverse; Geologic Traverse Planning for Apollo Missions; Desert Research and Technology Studies (DRATS) Traverse Planning; Science Traverses in the Canadian High Arctic; NOR-USA Scientific Traverse of East Antarctica: Science and Logistics on a Three-Month Expedition Across Antarctica's Farthest Frontier; A Notional Example of Understanding Human Exploration Traverses on the Lunar Surface; and The Princess Elisabeth Station.

  17. EEG effect of orexin A in freely moving rats.

    Science.gov (United States)

    Toth, A; Balatoni, B; Hajnik, T; Detari, L

    2012-09-01

    Orexin A and orexin B are neuropeptides produced by a group of neurons located in the lateral hypothalamus which send widespread projections virtually to the whole neuraxis. Several studies indicated that orexins play a crucial role in the sleep-wake regulation and in the pathomechanism of the sleep disorder narcolepsy. As no data are available related to the EEG effects of orexin A in healthy, freely moving rats, the aim of the present experiments was to analyze EEG power changes in the generally used frequency bands after intracerebroventricular orexin A administration.Orexin A administration (0.84 and 2.8 nM/rat) differently affected fronto-occipital EEG waves in the different frequency bands recorded for 24 hours. Delta (1-4 Hz) and alpha (10-16 Hz) power decreased, while theta (4-10 Hz) and beta (16-48 Hz) power increased. Decrease of the delta power was followed by a rebound in case of the higher orexin A dose. This complex picture might be explained by the activation of several systems by the orexin A administration. Among these systems, cortical and thalamic circuits as well as the role of the neurons containing corticotrophin-releasing factor might be of significant importance.

  18. Cyclothiazide induces seizure behavior in freely moving rats.

    Science.gov (United States)

    Kong, Shuzhen; Qian, Binbin; Liu, Jianhui; Fan, Mingxin; Chen, Gong; Wang, Yun

    2010-10-08

    We have previously demonstrated that cyclothiazide (CTZ) is a potent convulsant drug inducing robust epileptiform activity in hippocampal neurons both in vitro and in vivo. Here we further establish an animal model for CTZ-induced behavioral seizures in freely moving rats. Microinjection of CTZ into the left ventricle dose-dependently induced robust seizure behaviors within 3h after administration. At a dose of 0.75 μmol, CTZ induced Racine score IV-V seizure behaviors in 71% (n=14) of the rats were tested. In addition, CTZ also induced epileptiform EEG activity accompanying behavioral seizures. The convulsant action of CTZ on both behavior and EEG was blocked by pretreatment with clinical anticonvulsant drug diazepam (n=5). In conclusion, our results demonstrate that CTZ is capable of inducing behavioral seizures in intact animals. Since CTZ acts on both GABAergic and glutamatergic systems, this new animal epilepsy model will be useful for anticonvulsant drug testing and general epilepsy research. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. FREELY DECAYING TURBULENCE IN FORCE-FREE ELECTRODYNAMICS

    Energy Technology Data Exchange (ETDEWEB)

    Zrake, Jonathan; East, William E. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States)

    2016-02-01

    Freely decaying, relativistic force-free turbulence is studied for the first time. We initiate the magnetic field at a short wavelength and simulate its relaxation toward equilibrium on two- and three-dimensional periodic domains in both helical and nonhelical settings. Force-free turbulent relaxation is found to exhibit an inverse cascade in all settings and in three dimensions to have a magnetic energy spectrum consistent with the Kolmogorov 5/3 power law. Three-dimensional relaxations also obey the Taylor hypothesis; they settle promptly into the lowest-energy configuration allowed by conservation of the total magnetic helicity. However, in two dimensions, the relaxed state is a force-free equilibrium whose energy greatly exceeds the Taylor minimum and that contains persistent force-free current layers and isolated flux tubes. We explain this behavior in terms of additional topological invariants that exist only in two dimensions, namely the helicity enclosed within each level surface of the magnetic potential function. The speed and completeness of turbulent magnetic free-energy discharge could help account for rapidly variable gamma-ray emission from the Crab Nebula, gamma-ray bursts, blazars, and radio galaxies.

  20. Locomotor patterns in freely moving crayfish (Procambarus clarkii)

    Science.gov (United States)

    Jamon; Clarac

    1995-01-01

    Freely walking crayfish, Procambarus clarkii, were studied using a video analysis procedure adapted especially for use with crayfish. The animals were placed in a tank and their homing behaviour was filmed as they returned in a straight line to their shelter. Various sequences were studied at the two following levels. First, the trajectory of each pair of legs (from leg 2 to leg 5) during the step cycle (power stroke and return stroke) was studied to measure stride length and to analyse in detail changes in acceleration. Each leg was found to contribute in a specific manner to locomotion. Second, ipsi- and contralateral leg coordination was investigated. Ipsilateral coordination was found to involve a metachronal organization from front to back in all the walking sequences recorded, whereas contralateral coordination involved, in addition to the weak alternate coupling commonly observed in treadmill walking, another coordination pattern where the legs on each side (legs 3 and 4) are in phase. The results obtained in these free-walking sequences are discussed and compared with those obtained previously, in particular in treadmill situations.

  1. Freely suspended nanocomposite membranes as highly sensitive sensors.

    Science.gov (United States)

    Jiang, Chaoyang; Markutsya, Sergiy; Pikus, Yuri; Tsukruk, Vladimir V

    2004-10-01

    Highly sensitive sensor arrays are in high demand for prospective applications in remote sensing and imaging. Measuring microscopic deflections of compliant micromembranes and cantilevers is developing into one of the most versatile approaches for thermal, acoustic and chemical sensing. Here, we report on an innovative fabrication of compliant nanocomposite membranes with nanoscale thickness showing extraordinary sensitivity and dynamic range, which makes them candidates for a new generation of membrane-based sensor arrays. These nanomembranes with a thickness of 25-70 nm, which can be freely suspended over large (hundred micrometres) openings are fabricated with molecular precision by time-efficient, spin-assisted layer-by-layer assembly. They are designed as multilayered molecular composites made of a combination of polymeric monolayers and a metal nanoparticle intralayer. We demonstrate that these nanocomposite membranes possess unparalleled sensitivity and a unique autorecovering ability. The membrane nanostructure that is responsible for these outstanding properties combines multilayered polymer/nanoparticle organization, high polymer-chain orientation, and a pre-stretched state.

  2. Positron Annihilation in the Bipositronium Ps2

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, David H.; Frolov, Alexei M.

    2005-07-01

    The electron-positron-pair annihilation in the bipositronium PS2 is considered. In particular, the two-, three-, one- and zero-photon annihilation rates are determined to high accuracy. The corresponding analytical expressions are also presented. Also, a large number of bound state properties have been determined for this system.

  3. The 4 Ps as a Guiding Perspective

    Science.gov (United States)

    Kalsbeek, David H.

    2013-01-01

    A 4 Ps perspective addresses immediate needs: to help institutions gain traction in their retention strategies by framing and reframing the challenges and the possible responses, by challenging some of the traditional mental models about retention that can distract or dilute those strategies, and by offering focus and coherence to institutional…

  4. 10th Anniversary P.S.

    CERN Multimedia

    Adams,J

    1969-01-01

    John Adams parle de la préhistoire du P.S. avec présentation des dias. Le DG B.Gregory prend la parole. Les organisateurs présentent sous la direction du "Prof.Ocktette"(?) un sketch très humoristique (p.e.existence de Quark etc.....)

  5. Back to work for the PS

    CERN Multimedia

    2006-01-01

    On 22 June, the PS's rotating machine started turning again for the first time since its enforced shutdown one month ago (see Bulletin No. 23-24/2006) - and the PS was back in operation the very next day! A team from Siemens worked their socks off, 6 days a week for one month (including public holidays), to repair the electrical power supply in collaboration with the AB/PO Group's Main Power Converters (MPC) Section. The generator's faulty rotor was dismantled and replaced by the renovated spare rotor. The multitude of electrical and mechanical connections together with the sheer weight of the rotor (80 tonnes) made this an extremely complex job. The AB/PO Group used the shutdown to test a back-up solution for the PS power supply. The accelerator was directly wired up to the 18 kV electrical network via a 13 MVA transformer, installed at the end of the 1970s but never used. This solution succeeded in bringing the PS back into operation but at limited energy and frequency. Just 14 GeV could be achieved, whic...

  6. Which factors determine the freely chosen cadence during submaximal cycling?

    Science.gov (United States)

    Vercruyssen, Fabrice; Brisswalter, Jeanick

    2010-03-01

    The present review of cycling science focuses on the identification of criteria that affect the freely chosen cadence (FCC) during submaximal exercise of short and prolonged durations. Cadence selection during submaximal cycling constitutes a potential parameter affecting the endurance performance in subjects of varying aerobic fitness level and experience. The activity constraints such as specificity (e.g. cycle bout of triathlon) and exercise duration may play an important role in the selection of cadence and must be taken into consideration in the task description. The 'holistic' approach of this review is based on a multifactorial analysis considering the cycling constraints, and the physiological and biomechanical factors of cadence selection so as to establish any interrelationships between these factors. During cycle bouts of short duration (<15 min), it has been well argued that experienced cyclists, trained runners and triathletes adopt high cadences (80-100 rpm) systematically above the energetically optimal cadence (EOC) at which the oxygen uptake is minimal (55-65 rpm). The choice of a high cadence has been shown to be dependent upon several factors, such as the aerobic fitness level, the reduction in forces applied to the cranks, the lower extremity net joint moments and minimal neuromuscular fatigue. However, with increasing exercise duration the FCC has been reported to be close to the EOC exclusively in endurance athletes practising a variety of activities, suggesting an impact of training mode on the muscular adaptations and the organisation of the movement pattern. Copyright 2009 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  7. Navigating freely-available software tools for metabolomics analysis.

    Science.gov (United States)

    Spicer, Rachel; Salek, Reza M; Moreno, Pablo; Cañueto, Daniel; Steinbeck, Christoph

    2017-01-01

    The field of metabolomics has expanded greatly over the past two decades, both as an experimental science with applications in many areas, as well as in regards to data standards and bioinformatics software tools. The diversity of experimental designs and instrumental technologies used for metabolomics has led to the need for distinct data analysis methods and the development of many software tools. To compile a comprehensive list of the most widely used freely available software and tools that are used primarily in metabolomics. The most widely used tools were selected for inclusion in the review by either ≥ 50 citations on Web of Science (as of 08/09/16) or the use of the tool being reported in the recent Metabolomics Society survey. Tools were then categorised by the type of instrumental data (i.e. LC-MS, GC-MS or NMR) and the functionality (i.e. pre- and post-processing, statistical analysis, workflow and other functions) they are designed for. A comprehensive list of the most used tools was compiled. Each tool is discussed within the context of its application domain and in relation to comparable tools of the same domain. An extended list including additional tools is available at https://github.com/RASpicer/MetabolomicsTools which is classified and searchable via a simple controlled vocabulary. This review presents the most widely used tools for metabolomics analysis, categorised based on their main functionality. As future work, we suggest a direct comparison of tools' abilities to perform specific data analysis tasks e.g. peak picking.

  8. Droplet and cluster formation in freely falling granular streams.

    Science.gov (United States)

    Waitukaitis, Scott R; Grütjen, Helge F; Royer, John R; Jaeger, Heinrich M

    2011-05-01

    Particle beams are important tools for probing atomic and molecular interactions. Here we demonstrate that particle beams also offer a unique opportunity to investigate interactions in macroscopic systems, such as granular media. Motivated by recent experiments on streams of grains that exhibit liquid-like breakup into droplets, we use molecular dynamics simulations to investigate the evolution of a dense stream of macroscopic spheres accelerating out of an opening at the bottom of a reservoir. We show how nanoscale details associated with energy dissipation during collisions modify the stream's macroscopic behavior. We find that inelastic collisions collimate the stream, while the presence of short-range attractive interactions drives structure formation. Parameterizing the collision dynamics by the coefficient of restitution (i.e., the ratio of relative velocities before and after impact) and the strength of the cohesive interaction, we map out a spectrum of behaviors that ranges from gaslike jets in which all grains drift apart to liquid-like streams that break into large droplets containing hundreds of grains. We also find a new, intermediate regime in which small aggregates form by capture from the gas phase, similar to what can be observed in molecular beams. Our results show that nearly all aspects of stream behavior are closely related to the velocity gradient associated with vertical free fall. Led by this observation, we propose a simple energy balance model to explain the droplet formation process. The qualitative as well as many quantitative features of the simulations and the model compare well with available experimental data and provide a first quantitative measure of the role of attractions in freely cooling granular streams.

  9. Breaking the Game: The traversal of the emergent narrative in video games

    Directory of Open Access Journals (Sweden)

    Pedro Cardoso

    2013-12-01

    Full Text Available In video games the player’s actions shape the narrative of their personal experience, molding what otherwise would be a linear course. This emergent narrative is in a state of constant transformation, dependent on how the player influences it. This paper explores how the players traverse ergodic media such as video games and how narrative emerges from the interactions between them and the system. In a previous text we have proposed three types of traversal in video games (Cardoso & Carvalhais, 2013: 1 that in which the player has the ability to choose between mutually exclusive paths; 2 that in which the player has the ability to expand the narrative; and 3 that in which the traversal is determined by the disposition of the other actors in the game world towards the player and each other. This paper intends to further contribute by adding another one: 4 a type of traversal that is rooted in the exploitation of any flaws and glitches in the system, allowing the player to traverse the game through an overlooked side of the algorithm, journeying through a world of unpredictable behaviours and events, that may ultimately break the game altogether.  

  10. PS overcomes two serious magnet failures

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Two magnets (no.'s 6 and 19)and a bus bar connection in the PS were found to be faulty during high-voltage tests at the end of the accelerator shutdown. A five-week repair schedule was quickly devised. A team of mechanics, technicians and engineers worked at full speed to replace the faulty magnets, succeeding in limiting the delay of the accelerators' spring start-up to two weeks. Pictured here are members of the PS team with the replacement no. 6 magnet. From left to right: In the back row, Frédéric Roussel (Transport DBS), Yves Bernard (Transport DBS), Luc Moreno (Cegelec), Thierry Battimanza (Transport DBS), Raymond Brown (AB/ABP), Thomas Zickler (AT/MEL); at the front, Steven Southern (AT/VAC), Thierry Gaidon (Brun & Sorensen), Philippe Vidales (Cegelec), Daniel Aubert (Cegelec), Jerome Cachet (Transport DBS), Jose Manual Gomes de Faria (AT/MEL), Eric Page (AT/VAC).

  11. Curve walking in freely moving crayfish (Procambarus clarkii)

    Science.gov (United States)

    Domenici; Jamon; Clarac

    1998-05-01

    The curve walking of freely moving crayfish trained to walk along a curved path during homing behaviour was investigated using a video-analysis system. The leg kinematics and leg phase relationships, as well as the relationship between stepping patterns and body axis rotation measured relative to external references, were studied. The anterior and posterior extreme positions of the power stroke (AEP and PEP, respectively) and step amplitudes were analysed. As in a previous study on crayfish curve walking on a treadmill, PEPs were more posterior in outer legs (the legs on the outside of the turn) than in the inner legs. As a result, outer legs showed larger step amplitudes than inner legs. Leg kinematics varied within each walking sequence. AEP leg angles (the angles between the body and leg axes at the AEP) tended to decrease over time for inner legs and increase for outer legs. This leg angle drift was present mainly in the anterior legs and it suggests that these legs did not completely compensate for the body rotation after each step. In addition, leg angle asymmetries in a direction opposite to that of leg angle drift were observed at the start of each curve-walking sequence, suggesting that the extensive training (3 weeks) may have allowed crayfish to anticipate the leg angle drift. The rotational component of curve walking showed a discontinuous pattern, with the animal's body axis turning towards the inside of the curve only periodically. Analysis of cross-correlation functions showed that the angular acceleration of the body axis in the direction of the turn occurred during the power strokes of inner legs 2 and 5 and outer leg 4. While the tripod formed by these three legs showed in-phase relationships, the legs of the corresponding contralateral tripod (outer legs 2 and 5 and inner leg 4) were not in phase. We hypothesize that inner legs 2 and 5 and outer leg 4 act synergically causing the inward body rotation observed in curve-walking crayfish and that

  12. PS overcomes two serious magnet failures

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Two magnets and a bus bar connection in the PS were found to be faulty during high-voltage tests at the end of the accelerator shutdown. A five-week repair schedule was quickly devised. A team of mechanics, technicians and engineers worked at full speed to replace the faulty magnets, succeeding in limiting the delay of the accelerators´ spring start-up to two weeks. Here we see one of the replacement magnets (no. 19) being prepared.

  13. The PS overcomes two serious magnet failures

    CERN Multimedia

    2003-01-01

    Two magnets and a bus bar connection in the PS were found to be faulty during high-voltage tests at the end of the accelerator shutdown. A five-week repair schedule was quickly devised. A team of mechanics, technicians and engineers worked at full speed to replace the faulty magnets, succeeding in limiting the delay of the accelerators' spring start-up to two weeks.

  14. Motor-Generator Set, PS Main Supply

    CERN Multimedia

    CERN PhotoLab

    1983-01-01

    This is the "new" motor-generator set. It replaced the previous, original, one which had served from the PS start-up in 1959. Ordered in 1965, installed in 1967, it was brought into operation at the beginning of 1968. Regularly serviced and fitted with modern regulation and controls, it still serves at the time of writing (2006) and promises to serve for several more years, as a very much alive museum-piece. See also 6803016 and 0201010.

  15. Measuring target for the PS Booster

    CERN Multimedia

    1971-01-01

    The measuring target for the PS Booster (originally 800 MeV, now 1.4 GeV). It measures the size of the beam by destroying all particles with amplitudes greater than the size of the fork, the position and width of which are adjustable. The plunging time is only 20 ms and the acceleration at the tip of the fork reaches 90 g. The servo-controlled linear motor is shown detached from the mechanism. See also 7602008.

  16. Memories of the PS and of LEP

    CERN Document Server

    Steinberger, Jack

    2012-01-01

    The CERN PS, which started in 1959, and the Brookhaven AGS in 1960, represented an advance by a factor of more than five in the energy of proton accelerators, from the 5 GeV of the Berkeley Bevatron to about 30 GeV. These accelerators made possible the large progress in our understanding of particles and their interactions over the next two decades, culminating in the electroweak and QCD gauge theories.

  17. PS overcomes two serious magnet failures

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Two magnets and a bus bar connection in the PS were found to be faulty during high-voltage tests at the end of the accelerator shutdown. A five-week repair schedule was quickly devised. A team of mechanics, technicians and engineers worked at full speed to replace the faulty magnets, succeeding in limiting the delay of the accelerators' spring start-up to two weeks. Here we see one of the replacement magnets (no. 6) being prepared.

  18. Enhanced personal protection system for the PS

    CERN Multimedia

    Caroline Duc

    2013-01-01

    During the first long shutdown (LS1) a new safety system will be installed in the primary beam areas of the PS complex in order to bring the standard of personnel radiation protection at the PS into line with that of the LHC.   Pierre Ninin, deputy group leader of GS-ASE and responsible for the installation of the new PS complex safety system, in front of a new access control system. The LHC access control systems are state-of-the-art, whereas those of the injection chain accelerators were running the risk of becoming obsolete. For the past two years a project to upgrade the access and safety systems of the first links in the LHC accelerator chain has been underway to bring them into compliance with nuclear safety standards. These systems provide the personnel with automatic protection by limiting access to hazardous areas and by ensuring that nobody is present in the areas when the accelerator is in operation. By the end of 2013, the project teams will ha...

  19. Spin, torsion and violation of null energy condition in traversable wormholes

    Science.gov (United States)

    Di Grezia, Elisabetta; Battista, Emmanuele; Manfredonia, Mattia; Miele, Gennaro

    2017-12-01

    The static spherically symmetric traversable wormholes are analysed in the Einstein-Cartan theory of gravitation. In particular, we computed the torsion tensor for matter fields with different spin S=0, 1/2, 1, 3/2. Interestingly, only for certain values of the spin, the torsion contribution to the Einstein-Cartan field equation allows one to satisfy both flaring-out condition and null energy condition. In this scenario, traversable wormholes can be produced by using usual (non-exotic) spinning matter.

  20. 77 FR 25452 - Applications for New Awards; Territories and Freely Associated States Education Grant Program

    Science.gov (United States)

    2012-04-30

    ... Applications for New Awards; Territories and Freely Associated States Education Grant Program AGENCY: Office of...: Territories and Freely Associated States Education Grant Program; Notice inviting applications for new awards... Education Grant competition at www.Grants.gov . You must search for the downloadable application package for...

  1. 34 CFR 300.701 - Outlying areas, freely associated States, and the Secretary of the Interior.

    Science.gov (United States)

    2010-07-01

    ... Secretary of the Interior. 300.701 Section 300.701 Education Regulations of the Offices of the Department of..., freely associated States, and the Secretary of the Interior. (a) Outlying areas and freely associated... the Interior. From the amount appropriated for any fiscal year under section 611(i) of the Act, the...

  2. Mechanical properties of freely suspended semiconducting graphene-like layers based on MoS2

    NARCIS (Netherlands)

    Castellanos-Gomez, A.; Poot, M.; Steele, G.A.; Van der Zant, H.S.J.; Agrait, N.; Rubio-Bollinger, G.

    2012-01-01

    We fabricate freely suspended nanosheets of molybdenum disulphide (MoS2) which are characterized by quantitative optical microscopy and high-resolution friction force microscopy. We study the elastic deformation of freely suspended nanosheets of MoS2 using an atomic force microscope. The Young’s

  3. Micro-device combining electrophysiology and optical imaging for functional brain monitoring in freely moving animals

    Science.gov (United States)

    Miao, Peng; Wang, Qihong; Zhang, Lingke; Li, Miao; Thakor, Nitish V.

    2017-02-01

    Monitoring brain activities in awake and freely moving status is very important in physiological and pathological studies of brain functions. In this study, we developed a new standalone micro-device combining electrophysiology and optical imaging for monitoring the cerebral blood flow and neural activities with more feasibility for freely moving animals.

  4. Psühhodramaatikud annavad Pärnus eksami

    Index Scriptorium Estoniae

    2008-01-01

    29. maist kuni 1. juunini kestab Pärnus psühhodraama konverents "Geeniuste kohtumine", kus rahvusvahelise koolituse läbinud annavad eksami. Ruuda Palmquist on psühhodraama kui teadusharu rajajaid Eestis. Pärnus on kohal Rootsi Moreno Instituudi juhataja, psühhodraama lavastaja Marc Treadwell

  5. Master Plan for Public Use Development and Resource Management, Lake Traverse, Minnesota - South Dakota.

    Science.gov (United States)

    1979-05-01

    maize and beans which made a sedentary village complex possible. 2.5 The Cheyenne Indians reportedly lived in the Lake Traverse area as agriculturists...Engineering Division A-5 EXHIBIT 1 EXHIBITS OPARTMENT OF THE APMY ST PAUL DISTN’ICT coflSe ’ r m aNNrrtS 1135uU. S POST orrict Uso CICTM OUSE ST. PAUL

  6. Peano—A Traversal and Storage Scheme for Octree-Like Adaptive Cartesian Multiscale Grids

    KAUST Repository

    Weinzierl, Tobias

    2011-01-01

    Almost all approaches to solving partial differential equations (PDEs) are based upon a spatial discretization of the computational domain-a grid. This paper presents an algorithm to generate, store, and traverse a hierarchy of d-dimensional Cartesian grids represented by a (k = 3)- spacetree, a generalization of the well-known octree concept, and it also shows the correctness of the approach. These grids may change their adaptive structure throughout the traversal. The algorithm uses 2d + 4 stacks as data structures for both cells and vertices, and the storage requirements for the pure grid reduce to one bit per vertex for both the complete grid connectivity structure and the multilevel grid relations. Since the traversal algorithm uses only stacks, the algorithm\\'s cache hit rate is continually higher than 99.9 percent, and the runtime per vertex remains almost constant; i.e., it does not depend on the overall number of vertices or the adaptivity pattern. We use the algorithmic approach as the fundamental concept for a mesh management for d-dimensional PDEs and for a matrix-free PDE solver represented by a compact discrete 3 d-point operator. In the latter case, one can implement a Jacobi smoother, a Krylov solver, or a geometric multigrid scheme within the presented traversal scheme which inherits the low memory requirements and the good memory access characteristics directly. © 2011 Society for Industrial and Applied Mathematics.

  7. Proceedings 3rd Workshop on GRAPH Inspection and Traversal Engineering (GRAPHITE 2014)

    DEFF Research Database (Denmark)

    2014-01-01

    These are the proceedings of the Third Workshop on GRAPH Inspection and Traversal Engineering (GRAPHITE 2014), which took place on April 5, 2014 in Grenoble, France, as a satellite event of the 17th European Joint Conferences on Theory and Practice of Software (ETAPS 2014). The aim of GRAPHITE is...

  8. Psychometric properties of the French translation of the reduced KOOS and HOOS (KOOS-PS and HOOS-PS)

    DEFF Research Database (Denmark)

    Ornetti, P; Perruccio, A V; Roos, E M

    2009-01-01

    OBJECTIVE: To evaluate the psychometric properties of the French KOOS physical function (KOOS-PS) and HOOS physical function (HOOS-PS), specifically its feasibility, reliability, construct validity, and responsiveness. METHODS: Consecutive outpatients consulting for primary knee or hip osteoarthr......OBJECTIVE: To evaluate the psychometric properties of the French KOOS physical function (KOOS-PS) and HOOS physical function (HOOS-PS), specifically its feasibility, reliability, construct validity, and responsiveness. METHODS: Consecutive outpatients consulting for primary knee or hip...

  9. Evolving science enhanced with iPS

    Directory of Open Access Journals (Sweden)

    Editor

    2007-11-01

    Full Text Available Dear friends, Greetings from all in the team. With the stage set for online submissions and the review-response-revision-resubmission process standardized, we have come with the first regular issue and from now there will be quarterly issues of the journal. Since the starting of the JSRM in a short span there have been a lot of developments, which we would rather say as "evolutions" keeping in mind, the recent iPS! This evolution we would like you to see from a background of the various developments in the art and science of medicine throughout in the past three centuries. We have come across the era of investigative tools such as bamboo made laryngoscopes to era of vaccines and antibiotics followed by the era of revolutionary non-invasive procedures and recently the nano technology based drugs and now the iPS! Macro to Micro, but still more to go. All through the influence of the society, religions, philosophies have been playing a very important role in every step the science of biology moves ahead. Starting with the contraception, assisted reproduction then the gene modified plants....and now the embryonic stem cells! With the advent of the iPS, though the issues of oncogenes, teratoma yet to be ruled out, we have found there is a way which can bypass the ES cells! Hats off to those scientists who have burnt their midnight oil to have found this way out! The lesson we learn is to explore things with an open mind and continue to proceed further without spending much time fingers crossed. Yours sincerely,The Editorial team.

  10. Position pickup of the PS Booster

    CERN Multimedia

    CERN PhotoLab

    1975-01-01

    The beam position around the 4 rings of the PS Booster (originally 800 MeV, now 1.4 GeV), is measured with electrostatic pickups (PU). They consist of a ceramic cylinder forming part of the vacuum chamber, and, in order to save space, they are located inside the multipole lenses. The inside of the ceramic is coated with a metallic layer, into which the form of the electrodes was cut by computer-controlled micro-sandblasting. Each PU has a pair of horizontal and a pair of vertical electrodes, as well as a separate intensity-sensing circular electrode.

  11. Space charge studies in the PS

    CERN Document Server

    Asvesta, F; Damerau, H; Huschauer, A; Papaphilippou, Y; Serluca, M; Sterbini, G; Zisopoulos, P

    2017-01-01

    In this paper the results of Machine Development (MD)studies conducted at the CERN Proton Sychrotron (PS) arepresented. The main focus was the investigation of newworking points in an effort to characterize and potentiallyimprove the brightness for LHC-type beams in view of theLHC Injectors Upgrade (LIU). Various working points werecompared in terms of losses and emittance evolution. Sincespace charge and the resonances it excites are the main causefor emittance blow-up and losses, tunes close to excitedresonances were carefully studied. Mitigation techniques,such as bunch flattening using a double harmonic RF system,were also tested.

  12. 78 FR 37966 - Safety Zone; National Cherry Festival Air Show and Fireworks Display, West Grand Traverse Bay...

    Science.gov (United States)

    2013-06-25

    ... operators of vessels intending to transit around West Grand Traverse Bay, Traverse City, Michigan, between... small business, organization, or governmental jurisdiction and you have questions concerning its... of power and responsibilities among the various levels of government. We have analyzed this rule...

  13. PAN/PS elctrospun fibers for oil spill cleanup

    Science.gov (United States)

    Ying, Qiao; Lili, Zhao; Haixiang, Sun; Peng, Li

    2014-08-01

    A high-capacity oil sorbent was fabricated by electrospinning using PS/PAN blend. Morphology, contact angle and oil adsorption of PAN/PS fiber and PP nonwoven fabric were studied. It was found that the PAN/PS fiber had a smaller diameter than PP, and the maximum sorption capacities of the PAN/PS sorbent for pump oil, peanut oil, diesel, and gasoline were 194.85, 131.7, 66.75, and 43.38 g/g, which were far higher than those of PP. The sorbent PS/PAN fiber showed a contact angle of water144.32° and diesel oil 0°. The sorption kinetics of PAN/PS and PP sorbent were also investigated. Compared with the commercial PP fabric, the PAN/PS fiber seems to have the ability to be used in oil-spill cleanup application.

  14. Chemotherapy and quality of life in NSCLC PS 2 patients

    DEFF Research Database (Denmark)

    Helbekkmo, Nina; Strøm, Hans H; Sundstrøm, Stein H

    2009-01-01

    INTRODUCTION: Nearly 40% of patients with advanced NSCLC are in performance status (PS) 2. These patients have a shorter life expectancy than PS 0/1 patients and they are underrepresented in clinical trials. Data on how platinum-based combination chemotherapy affects Health Related Quality of Life...... (HRQOL) of patients with PS 2 are scarce and the treatment of this important group of patients is controversial. METHODS: A national multicenter phase III study on platinum based chemotherapy to 432 advanced NSCLC patients included 123 patients with PS 2. To explore the treatment impact on HRQOL......: Whereas the demographic data at baseline were well balanced between the groups, the PS 2 patients had significantly worse function and more severe symptoms than the PS 0/1 patients. In response to combination chemotherapy, the PS 2 patients had a more profound improvement of global QOL, cognitive function...

  15. The PS Booster Fast Wire Scanner

    CERN Document Server

    Burger, S; Priestnall, K; Raich, U

    2003-01-01

    The very tight emittance budget for LHC type beams makes precise emittance measurements in the injector complex a necessity. The PS machine uses 2 fast wire scanners per transverse plane for emittance measurement of the circulating beams. In order to ease comparison the same type of wire scanners have been newly installed in the upstream machine, the PS Booster, where each of the 4 rings is equipped with 2 wire scanners measuring the horizontal and vertical profiles. Those wire scanners use new and more modern control and readout electronics featuring dedicated intelligent motor movement controllers, which relieves the very stringent real time constraints due to the very high speed of 20m/s. In order to be able to measure primary beams at the very low injection energy of the Booster (50MeV) secondary emission currents from the wire can be measured as well as secondary particle flows at higher primary particle energies during and after acceleration. The solution adopted for the control of the devices is descri...

  16. Sofrimento psíquico e trabalho

    Directory of Open Access Journals (Sweden)

    Sarah Rosa Salles Vieira

    2014-03-01

    Full Text Available O presente artigo aprofunda questões clínico-téoricas relacionadas especificamente ao trabalho docente e ao sofrimento psíquico a ele relacionado a partir da observação clínica e vivência grupal nos atendimentos terapêuticos ocupacionais realizados no Hospital do Servidor Público Estadual de São Paulo "Francisco Morato de Oliveira" (HSPE-FMO. Partindo dos estudos acerca da Psicopatologia do Trabalho de Christophe Dejours, do trabalho docente e do relato de um caso clínico, caracteriza a problemática do sofrimento no trabalho, os sistemas de defesa contra este sofrimento, a ameaça à subjetividade do próprio trabalhador, as representações e conflitos vivenciados no trabalho docente, bem como a relação aditiva estabelecida como uma estratégia inconsciente de sobrevivência psíquica.

  17. Action and the representation of distance in cognitive maps acquired through imagined traversal: the development of a new methodology.

    Science.gov (United States)

    Bugmann, Davi; Coventry, Kenny R

    2008-04-01

    A new methodology examined the effects of action on memory for traversed distance using an imagined route traversal task. Blindfolded participants learned environments through auditory verbal description, imagining themselves walking in synchronization with metronome beats. Participants were turned during traversals, and performed an action at midroute. Memory for the newly learned environments was tested through recall (measured with metronome beats). Experiments 1-3 indicated that the number (but not amplitude) of turns while imagining walking a set distance leads to an increase in perceived distance at recall. Additionally, Experiment 2 found that rewalked distance immediately prior to performing an action at midroute was greater than rewalked distance immediately after action. However, Experiment 3 established that the effect was due to time spent at midroute rather than action per se. The similarity between spatial representation derived from imagined traversal and real traversal, and the relationship between distance and time estimation are discussed.

  18. KAJIAN INDUCED PLURIPOTENT STEMCELL (iPS (HARAPAN DAN TANTANGAN

    Directory of Open Access Journals (Sweden)

    Masagus Zainuri

    2014-05-01

    Full Text Available AbstractInduced Pluripotent Stemcell (iPS are adult cells which the genetic information in the nucleus of those cells being reprogrammed (reprogram by inserting exogenous pluripotential genes. The exogenous gene transduction is using vectors, such as lentivirus, retrovirus, or adenovirus, which suppressed the gene expression of the original cells, so they will express the transduced exogenous gene. Viral vectors are then used to reprogramming and producing iPS clones that are pluripotent. iPS derived from adult cells of patient with certain diseases will be used as a tool to study the mechanisms of those specific diseases and the effects of selected drugs against the diseases. Several previous studies have shown that iPS clones developed from specific genetic disease have its original genotype and retain the character of the response to the drug that similar as the original adult cells. Opportunities for the utilization of autologous iPS cell therapy in the future is wide open as expected iPS transplant will not be rejected when transplanted back to the patient. Behind all its potential, iPS production is still facing some problems to be applicable clinically. The use of viruses as vectors may cause problems due to virus gene sequences may be integrated into the genome of the DNA donor cell, thereby causing mutations of the iPS clones. Several subsequent studies have succeeded in replacing the use of viruses as vectors, but the level of efficiency obtained is still very low. Another problem that arises is that epigenetic changes may occur in iPS cultures. Many advanced research related to iPS may be developed in Indonesia and is necessary to improve the production efficiency of iPS and solve iPS clones epigenetic changes problems in the future.Keywords: iPS, pluripotency, transduction, transfection.AbstrakInduced Pluripotent Stemcell (iPS adalah sel somatic dewasa yang informasi genetika dalam inti selnyadiprogram ulang (reprogram dengan cara

  19. Comparison of molecular species of various transphosphatidylated phosphatidylserine (PS) with bovine cortex PS by mass spectrometry

    NARCIS (Netherlands)

    Chen, S.; Li, K.W.

    2008-01-01

    The exogenous introduction of a molecular species mixture of bovine cortex phosphatidylserine (BC-PS) has been claimed to improve memory function in subjects suffering from age-associated memory impairment and dementia. However, it has been also reported that oral administration of another molecular

  20. Passive sampling methods for contaminated sediments: Scientific rationale supporting use of freely dissolved concentrations

    DEFF Research Database (Denmark)

    Mayer, Philipp; Parkerton, Thomas F.; Adams, Rachel G.

    2014-01-01

    Passive sampling methods (PSMs) allow the quantification of the freely dissolved concentration (Cfree ) of an organic contaminant even in complex matrices such as sediments. Cfree is directly related to a contaminant's chemical activity, which drives spontaneous processes including diffusive upta...

  1. Cavity Resonator Wireless Power Transfer System for Freely Moving Animal Experiments.

    Science.gov (United States)

    Mei, Henry; Thackston, Kyle A; Bercich, Rebecca A; Jefferys, John G R; Irazoqui, Pedro P

    2017-04-01

    The goal of this paper is to create a large wireless powering arena for powering small devices implanted in freely behaving rodents. We design a cavity resonator based wireless power transfer (WPT) system and utilize our previously developed optimal impedance matching methodology to achieve effective WPT performance for operating sophisticated implantable devices, made with miniature receive coils (powering fidelity of 93.53% over nine recording sessions across nine weeks, indicating nearly continuous device operation for a freely behaving rat within the large cavity resonator space. We have developed and demonstrated a cavity resonator based WPT system for long term experiments involving freely behaving small animals. This cavity resonator based WPT system offers an effective and simple method for wirelessly powering miniaturized devices implanted in freely moving small animals within the largest space.

  2. View of a stone age adze cutting tool floating freely in the flight deck.

    Science.gov (United States)

    1992-01-01

    View of a stone age adze cutting tool floating freely in the forward flight deck and framed by the forward and side windows. On the Earth below, the big island of Hawaii can be seen through the window.

  3. PS main supply: motor-generator set.

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    In picture 04 the motor is on the right in the background and the main view is of the generator. The peak power in each PS cycle drawn from the generator, up to 96 MW, is taken from the rotational kinetic energy of the rotor (a heavy-weight of 80 tons), which makes the rotational speed drop by only a few percent. The motor replenishes the average power of 2 to 4 MW. Photo 05: The motor-generator set is serviced every year and, in particular, bearings and slip-rings are carefully checked. To the left is the motor with its slip-rings visible. It has been detached from the axle and moved to the side, so that the rotor can be removed from the huge generator, looming at the right.

  4. The Fate of a Normal Human Cell Traversed by a Single Charged Particle

    Science.gov (United States)

    Fournier, C.; Zahnreich, S.; Kraft, D.; Friedrich, T.; Voss, K.-O.; Durante, M.; Ritter, S.

    2012-09-01

    The long-term ``fate'' of normal human cells after single hits of charged particles is one of the oldest unsolved issues in radiation protection and cellular radiobiology. Using a high-precision heavy-ion microbeam we could target normal human fibroblasts with exactly one or five carbon ions and measured the early cytogenetic damage and the late behaviour using single-cell cloning. Around 70% of the first cycle cells presented visible aberrations in mFISH after a single ion traversal, and about 5% of the cells were still able to form colonies. In one third of selected high-proliferative colonies we observed clonal (radiation-induced) aberrations. Terminal differentiation and markers of senescence (PCNA, p16) in the descendants of cells traversed by one carbon ion occurred earlier than in controls, but no evidence of radiation-induced chromosomal instability was found. We conclude that cells surviving single-ion traversal, often carrying clonal chromosome aberrations, undergo accelerated senescence but maintain chromosomal stability.

  5. The Fate of a Normal Human Cell Traversed by a Single Charged Particle

    Science.gov (United States)

    Fournier, C.; Zahnreich, S.; Kraft, D.; Friedrich, T.; Voss, K.-O.; Durante, M.; Ritter, S.

    2012-01-01

    The long-term “fate” of normal human cells after single hits of charged particles is one of the oldest unsolved issues in radiation protection and cellular radiobiology. Using a high-precision heavy-ion microbeam we could target normal human fibroblasts with exactly one or five carbon ions and measured the early cytogenetic damage and the late behaviour using single-cell cloning. Around 70% of the first cycle cells presented visible aberrations in mFISH after a single ion traversal, and about 5% of the cells were still able to form colonies. In one third of selected high-proliferative colonies we observed clonal (radiation-induced) aberrations. Terminal differentiation and markers of senescence (PCNA, p16) in the descendants of cells traversed by one carbon ion occurred earlier than in controls, but no evidence of radiation-induced chromosomal instability was found. We conclude that cells surviving single-ion traversal, often carrying clonal chromosome aberrations, undergo accelerated senescence but maintain chromosomal stability. PMID:22966418

  6. PS: A nonprocedural language with data types and modules

    Science.gov (United States)

    Gokhale, M. B.

    1986-01-01

    The Problem Specification (PS) nonprocedural language is a very high level language for algorithm specification. PS is suitable for nonprogrammers, who can specify a problem using mathematically-oriented equations; for expert programmers, who can prototype different versions of a software system for evaluation; and for those who wish to use specifications for portions (if not all) of a program. PS has data types and modules similar to Modula-2. The compiler generates C code. PS is first shown by example, and then efficiency issues in scheduling and code generation are discussed.

  7. Distinct iPS Cells Show Different Cardiac Differentiation Efficiency.

    Science.gov (United States)

    Ohno, Yohei; Yuasa, Shinsuke; Egashira, Toru; Seki, Tomohisa; Hashimoto, Hisayuki; Tohyama, Shugo; Saito, Yuki; Kunitomi, Akira; Shimoji, Kenichiro; Onizuka, Takeshi; Kageyama, Toshimi; Yae, Kojiro; Tanaka, Tomofumi; Kaneda, Ruri; Hattori, Fumiyuki; Murata, Mitsushige; Kimura, Kensuke; Fukuda, Keiichi

    2013-01-01

    Patient-specific induced pluripotent stem (iPS) cells can be generated by introducing transcription factors that are highly expressed in embryonic stem (ES) cells into somatic cells. This opens up new possibilities for cell transplantation-based regenerative medicine by overcoming the ethical issues and immunological problems associated with ES cells. Despite the development of various methods for the generation of iPS cells that have resulted in increased efficiency, safety, and general versatility, it remains unknown which types of iPS cells are suitable for clinical use. Therefore, the aims of the present study were to assess (1) the differentiation potential, time course, and efficiency of different types of iPS cell lines to differentiate into cardiomyocytes in vitro and (2) the properties of the iPS cell-derived cardiomyocytes. We found that high-quality iPS cells exhibited better cardiomyocyte differentiation in terms of the time course and efficiency of differentiation than low-quality iPS cells, which hardly ever differentiated into cardiomyocytes. Because of the different properties of the various iPS cell lines such as cardiac differentiation efficiency and potential safety hazards, newly established iPS cell lines must be characterized prior to their use in cardiac regenerative medicine.

  8. Traverses for lunar rovers and sample return teleoperated from Earth or cislunar orbit

    Science.gov (United States)

    Kamps, Oscar; Foing, Bernard H.; Flahaut, Jessica

    2016-07-01

    Most interesting sites for exploration are near the poles of the Moon where water and other ices and volatiles could be stable in the permanent shaded regions. Several instruments on multiple orbiters have indicated the presence of hydrogen or hydration but the relation with the illumination conditions are not as clear. Which other variables are involved to trap water near the poles is not known. This ignorance makes it of high interest to do in-situ research on the Moon. ESA, NASA and other agencies are studying a teleoperated mission from cislunar orbit with Orion (eg. HERACLES international lunar exploration architecture) with the possibility of long rover traverses, and human assisted sample return. This mission concept was used for this study on a rover traverse. This study focuses on both the North as South Pole. The site selection for a traverse was based on the temperature map from Diviner. Regions of interests were made as primary selection and cover areas where the maximum temperature is lower than the sublimation temperature of CO2. Data from neutron spectrometer from the Prospector, and crater epoch according to the USGS were used to make a selection of regions of interest. These selected sites where studied on their accessibility for a rover, based on the slope map made from the LOLA elevation model. A landing site was selected based on assumptions that it should be at least one kilometre in diameter and have a slope lower than 5 degrees. The temperature difference (Tmax-Tmin from the Diviner measurements) was used select a scientifically interesting site between the landing site and destination inside a PSR. It was thought that a site with a temperature difference larger than 150K is interesting to study volatile migration processes. Eventually for the traverse planning a tool in ArcGIS was used which calculates the easiest from one location to another where the slope is used as limiting factor. We give the example study of rover traverse planning

  9. Spectral analyses of PGO-on neurons during paradoxical sleep in freely moving cats.

    Science.gov (United States)

    Sei, H; Sakai, K; Yamamoto, M; Jouvet, M

    1993-05-28

    We have investigated the power spectral density (PSD) characteristics of spontaneous neuronal activities during paradoxical sleep (PS), including phasically firing PGO-on and tonically discharging type I-R neurons in the pontine tegmentum. The PSD of lateral geniculate PGO waves and blood pressure (BP) were also examined. During PS, the PSD of PGO-on neurons and PGO waves showed an almost white noise-like pattern, while that of TI-R neurons and BP exhibited a 1/f spectrum. It appears, therefore, that the neuronal and autonomic slow fluctuations found in the 1/f spectrum during PS are not driven by the PGO wave system.

  10. LEADIR-PS: providing unprecedented SMR safety and economics

    Energy Technology Data Exchange (ETDEWEB)

    Hart, R.S., E-mail: N2i2@xplornet.ca [Northern Nuclear Industries Incorporated, Cambridge, ON (Canada)

    2015-07-01

    Northern Nuclear Industries Incorporated (N{sup 2} I{sup 2}) is developing Small Modular Reactors (SMRs) called LEADIR-PS, an acronym for LEAD-cooled Integral Reactor-Passively Safe. LEADIR-PS integrates proven technologies including TRISO fuel, Pebble Bed core and graphite moderator, with molten lead coolant in an integral pool type reactor configuration to achieve unprecedented safety and economics. Plants under development are LEADIR-PS30, producing 30 MWth, LEADIR-PS100 producing 100 MWth and LEADIR-PS300 producing 300 MWth that are focused on serving the energy demands of areas with a small electrical grid and/or process heat applications. A plant consisting of six LEADIR-PS300 reactor modules serving a common turbine-generator, called the LEADIR-PS Six-Pack, is focused on serving areas with higher energy demands and a robust electricity grid. The Gen{sup +} I LEADIR-PS plants are inherently/passively safe. There is no potential for a Loss Of Coolant Accident, a reactivity transient without shutdown, a loss of heat sink, or hydrogen generation. No active systems or operator actions are required to assure safety. The unprecedented safety of LEADIR-PS reactors avoids large exclusion radius and demanding evacuation plan requirements. LEADIR-PS, with steam conditions of 370 {sup o}C and 12 MPa can serve over 85% of the world's non-transportation process heat demands. In Canada, the electricity and process heat demands, ranging from those of remote communities and the oil sands to densely populated areas can be served by LEADIR-PS. (author)

  11. ToPS: a framework to manipulate probabilistic models of sequence data.

    Directory of Open Access Journals (Sweden)

    André Yoshiaki Kashiwabara

    Full Text Available Discrete Markovian models can be used to characterize patterns in sequences of values and have many applications in biological sequence analysis, including gene prediction, CpG island detection, alignment, and protein profiling. We present ToPS, a computational framework that can be used to implement different applications in bioinformatics analysis by combining eight kinds of models: (i independent and identically distributed process; (ii variable-length Markov chain; (iii inhomogeneous Markov chain; (iv hidden Markov model; (v profile hidden Markov model; (vi pair hidden Markov model; (vii generalized hidden Markov model; and (viii similarity based sequence weighting. The framework includes functionality for training, simulation and decoding of the models. Additionally, it provides two methods to help parameter setting: Akaike and Bayesian information criteria (AIC and BIC. The models can be used stand-alone, combined in Bayesian classifiers, or included in more complex, multi-model, probabilistic architectures using GHMMs. In particular the framework provides a novel, flexible, implementation of decoding in GHMMs that detects when the architecture can be traversed efficiently.

  12. The HARP detector at the CERN PS

    CERN Document Server

    Catanesi, M G; Radicioni, E; Simone, S; Edgecock, R; Ellis, M; Robbins, S; Soler, F J P; Gößling, C; Mass, M; Bunyatov, S; Chukanov, A; Klimov, O; Krasin, I; Krasnoperov, A; Kustov, D; Popov, B; Serdiouk, V; Tereshchenko, V; Carassiti, V; Di Capua, E; Evangelisti, F; Vidal-Sitjes, G; Artamonov, A; Arce, P; Brocard, R; Decreuse, G; Friend, B; Giani, S; Gilardoni, S; Gorbunov, p; Grant, A; Grossheim, A; Gruber, P; Ivanchenko, V; Legrand, J C; Kayis-Topaksu,A; Panman, P; Papadopoulos, I; Pasternak, J; Chernyaev, E; Tsukerman, I; van der Vlugt, R; Veenhof, R; Wiebusch, C; Zucchelli, P; Blondel, A; Borghi, S; Campanelli, M; Cervera-Villanueva, A; Morone, M C; Prior, G; Schroeter, R; Kato, I; Gastaldi, Ugo; Mills, G B; Graulich, J S; Grégoire, G; Bonesini, M; Chignoli, F; Ferri, F; Paleari, F; Kirsanov, M; Postoev, V; Bagulya A; Grichine, V; Polukhina, N; Palladino, V; Coney, L; Schmitz, D; Barr, G; De Santo, A; Pattison, C; Zuber, K; Barichello, G; Bobisut, F; Gibin, D; Guglielmi, A; Laveder, M; Menegolli, A; Mezzetto M; Pepato, Adriano; Dumarchez, J; Troquereau, S; Vannucci, F; Dore, U; Iaciofano, A; Lobello, M; Marinilli, F; Orestano, D; Panayotov, D; Pasquali, M; Pastore, F; Tonazzo, A; Tortora, L; Booth, C; Buttar, C; Hodgson, P; Howlett, L; Nicholson, R; Bogomilovw, M; Burin, K; Chizhov, M; Kolev, D; Petev, P; Rusinov, I; Tsenov, R; Piperov, S; Temnikov, P; Apollonio, M; Chimenti, P; Giannini, G; Santin, G; Burguet-Castell, J; Gómez-Cadenas, J J; Novella, P; Sorel, M; Tornero, A

    2007-01-01

    HARP is a high-statistics, large solid angle experiment to measure hadron production using proton and pion beams with momenta between 1.5 and 15 GeV/c impinging on many different solid and liquid targets from low to high Z. The experiment, located in the T9 beam of the CERN PS, took data in 2001 and 2002. For the measurement of momenta of produced particles and for the identification of particle types, the experiment includes a large-angle spectrometer, based on a Time Projection Chamber and a system of Resistive Plate Chambers, and a forward spectrometer equipped with a set of large drift chambers, a threshold Cherenkov detector, a time-of-flight wall and an electromagnetic calorimeter. The large angle system uses a solenoidal magnet, while the forward spectrometer is based on a dipole magnet. Redundancy in particle identification has been sought, to enable the cross-calibration of efficiencies and to obtain a few percent overall accuracy in the cross-section measurements. Detector construction, operation an...

  13. Kevin Traverse-Healy: kommunikatsiooni eesmärk on muuta käitumist / intervjueerinud Annela Laaneots

    Index Scriptorium Estoniae

    Traverse-Healy, Kevin

    2013-01-01

    Intervjuu strateegianõuniku ja rahvusvaheliselt tuntud kommunikatsioonieksperdi Kevin Traverse-Healyga, kes peab eduka kommunikatsioonijuhi töös oluliseks luua õige kommunikatsioon, mille eesmärgiks on sihtrühma käitumise muutus

  14. Interleaving of beam lines inside the PS tunnel

    CERN Multimedia

    1983-01-01

    View against the direction of the proton beams. The PS ring (section 26) is on the left. The injection tunnel for LEAR leaving from here has increased the trafic in this already busy area where the two Linacs and the transfer tunnel leading to the SPS, ISR and AA join the PS ring (cf. photo 7802260, 7802261, Annual Report 1981, p. 89, fig. 12).

  15. Modulation of enzymatic PS synthesis by liposome membrane composition.

    Science.gov (United States)

    Pinsolle, Alexandre; Roy, Philippe; Cansell, Maud

    2014-03-01

    Phosphatidylserine (PS) is a phospholipid known to exert important physiological roles in humans. However, this phospholipid (PL) is poorly available as a natural source and hardly produced by the chemical route. In this work, PS was obtained by transphosphatidylation using phospholipase D (PLD) and PL self-assembled into liposomes as the substrates. The aim was to better understand how the liposome membrane composition could modulate PS yield. Three lecithins were used as PL substrates, one originated from a marine source providing a high amount of n-3 polyunsaturated fatty acids, and two issued from soya differing in their phosphatidylcholine (PC) content. Different parameters such as Ca(2+) content, enzyme and L-serine concentrations modulated PS synthesis. The presence of Ca(2+) increased PS conversion yield. The alcohol acceptor (L-serine) concentration positively acted on PL conversion, by governing the equilibrium between transphosphatidylation and hydrolysis. Beside these specific reaction conditions, it was demonstrated that the membrane composition of the liposomes modulated PS synthesis. A direct correlation between PS accumulation and the amount of cholesterol or α-tocopherol incorporated into the soya lecithins was observed. This result was interpreted in terms of "head" spacers promoting PLD transphosphatidylation. On the whole, this work provided key parameters for the formulation of liposomes using enzymatic PLD technology, to produce lecithins enriched in different proportions of PS and esterified with various types of fatty acids depending on the initial lecithin source. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Spectroscopic Classification of PS16chs with SOAR/Goodman

    Science.gov (United States)

    Miller, J. A.; Hounsell, R. A.; Pan, Y.-C.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

    2016-05-01

    We report the classification of PS16chs from spectroscopic observation with the Goodman spectrograph on the SOAR telescope. The observation was made on 2016 May 08 UT. We classify PS16chs as a SN Ia near maximum light at z = 0.19.

  17. Motor-Generator powering the PS (Proton Synchrotron) main magnets

    CERN Multimedia

    1983-01-01

    This motor-generator,30 MW peak, 1500 r.p.m.,pulsed power supply for the PS main magnet replaced in 1968 the initial 3000 r.p.m. motor-generator-flywheel set which had served from the PS start-up in 1959 until end 1967. See also photo 8302337 and its abstract.

  18. Transfer line TT70 (electrons from PS to SPS)

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    As injectors for LEP, PS and SPS had to be converted to the acceleration of electrons and positrons. So far, only positively charged particles had been transferred from the PS to the SPS, for the negatively charged electrons a new transfer line, TT70, had to be built. Due to the difference in level of the two machines, the transfer line slopes and tilts.

  19. Psühhodraama - spontaansuse kool / Taimi Elenurm

    Index Scriptorium Estoniae

    Elenurm, Taimi

    2010-01-01

    Viinis ja New Yorgis tegutsenud psühhiaatri Jakob Levy Moreno loodud psühhodraamast, mis võimaldab rollimängu kaudu näha ennast läbi teiste silmade, aga ka vabaneda pingetest andes võimaluse käituda teisiti kui tavaelus

  20. Successful online learning – the five Ps

    Directory of Open Access Journals (Sweden)

    Jim FLOOD

    2004-04-01

    Full Text Available Successful online learning – the five Ps Jim FLOOD E-learning Consultant-UK jimflood@btinternet.com Key learning points • An important aspect of design for online learning is visual ergonomics. • Learning theories offer poor predictive power in terms of how learners work and learn. • Success at learning is closely related to emotional engagement–and learning designers tend to ignore this aspect. • Online learning poses a challenging experience for learners–and they need support to cope with it. • A key goal to achieve Praxis – being able to put learning into practice. Many of you will be familiar with the three (or more Ps of marketing and even if not, as trainers or teachers you are likely to have used mnemonics as an aid to retention and recall. Mnemonics are especially useful when you need to get the key points to ‘stick’ in the minds of your audience. With this in mind I offer you the 5 Ps of online learning: Presentation, Pedagogy, Promotion, Preparation and Props. What I offer is not new; in fact much of it results from the eleven years of online teaching and learning at The Open University, the £22 million it has spent on research and evaluation 1, and the worldwide community that have been sharing experience in recent years. You can therefore consider these 5 Ps to be a convenient re-packing of the information and experience that can be found in abundance on the Internet. Presentation Good graphic design appeals to the subtle process by which the brain processes information and, as a result, we decide if we like the ‘look and feel’ of a visual environment. Part of liking this ‘look and feel’ is the way the text and pictorial layout can appear inviting and encouraging–a vital aspect of any online learning environment. Another aspect of presentation is how the text reads in terms of engaging the learner and introducing the story to be told–as well as being written in clear and concise English When browsing through books

  1. Telomere reprogramming and maintenance in porcine iPS cells.

    Directory of Open Access Journals (Sweden)

    Guangzhen Ji

    Full Text Available Telomere reprogramming and silencing of exogenous genes have been demonstrated in mouse and human induced pluripotent stem cells (iPS cells. Pigs have the potential to provide xenotransplant for humans, and to model and test human diseases. We investigated the telomere length and maintenance in porcine iPS cells generated and cultured under various conditions. Telomere lengths vary among different porcine iPS cell lines, some with telomere elongation and maintenance, and others telomere shortening. Porcine iPS cells with sufficient telomere length maintenance show the ability to differentiate in vivo by teratoma formation test. IPS cells with short or dysfunctional telomeres exhibit reduced ability to form teratomas. Moreover, insufficient telomerase and incomplete telomere reprogramming and/or maintenance link to sustained activation of exogenous genes in porcine iPS cells. In contrast, porcine iPS cells with reduced expression of exogenous genes or partial exogene silencing exhibit insufficient activation of endogenous pluripotent genes and telomerase genes, accompanied by telomere shortening with increasing passages. Moreover, telomere doublets, telomere sister chromatid exchanges and t-circles that presumably are involved in telomere lengthening by recombination also are found in porcine iPS cells. These data suggest that both telomerase-dependent and telomerase-independent mechanisms are involved in telomere reprogramming during induction and passages of porcine iPS cells, but these are insufficient, resulting in increased telomere damage and shortening, and chromosomal instability. Active exogenes might compensate for insufficient activation of endogenous genes and incomplete telomere reprogramming and maintenance of porcine iPS cells. Further understanding of telomere reprogramming and maintenance may help improve the quality of porcine iPS cells.

  2. Telomere reprogramming and maintenance in porcine iPS cells.

    Science.gov (United States)

    Ji, Guangzhen; Ruan, Weimin; Liu, Kai; Wang, Fang; Sakellariou, Despoina; Chen, Jijun; Yang, Yang; Okuka, Maja; Han, Jianyong; Liu, Zhonghua; Lai, Liangxue; Gagos, Sarantis; Xiao, Lei; Deng, Hongkui; Li, Ning; Liu, Lin

    2013-01-01

    Telomere reprogramming and silencing of exogenous genes have been demonstrated in mouse and human induced pluripotent stem cells (iPS cells). Pigs have the potential to provide xenotransplant for humans, and to model and test human diseases. We investigated the telomere length and maintenance in porcine iPS cells generated and cultured under various conditions. Telomere lengths vary among different porcine iPS cell lines, some with telomere elongation and maintenance, and others telomere shortening. Porcine iPS cells with sufficient telomere length maintenance show the ability to differentiate in vivo by teratoma formation test. IPS cells with short or dysfunctional telomeres exhibit reduced ability to form teratomas. Moreover, insufficient telomerase and incomplete telomere reprogramming and/or maintenance link to sustained activation of exogenous genes in porcine iPS cells. In contrast, porcine iPS cells with reduced expression of exogenous genes or partial exogene silencing exhibit insufficient activation of endogenous pluripotent genes and telomerase genes, accompanied by telomere shortening with increasing passages. Moreover, telomere doublets, telomere sister chromatid exchanges and t-circles that presumably are involved in telomere lengthening by recombination also are found in porcine iPS cells. These data suggest that both telomerase-dependent and telomerase-independent mechanisms are involved in telomere reprogramming during induction and passages of porcine iPS cells, but these are insufficient, resulting in increased telomere damage and shortening, and chromosomal instability. Active exogenes might compensate for insufficient activation of endogenous genes and incomplete telomere reprogramming and maintenance of porcine iPS cells. Further understanding of telomere reprogramming and maintenance may help improve the quality of porcine iPS cells.

  3. Cockroaches traverse crevices, crawl rapidly in confined spaces, and inspire a soft, legged robot.

    Science.gov (United States)

    Jayaram, Kaushik; Full, Robert J

    2016-02-23

    Jointed exoskeletons permit rapid appendage-driven locomotion but retain the soft-bodied, shape-changing ability to explore confined environments. We challenged cockroaches with horizontal crevices smaller than a quarter of their standing body height. Cockroaches rapidly traversed crevices in 300-800 ms by compressing their body 40-60%. High-speed videography revealed crevice negotiation to be a complex, discontinuous maneuver. After traversing horizontal crevices to enter a vertically confined space, cockroaches crawled at velocities approaching 60 cm⋅s(-1), despite body compression and postural changes. Running velocity, stride length, and stride period only decreased at the smallest crevice height (4 mm), whereas slipping and the probability of zigzag paths increased. To explain confined-space running performance limits, we altered ceiling and ground friction. Increased ceiling friction decreased velocity by decreasing stride length and increasing slipping. Increased ground friction resulted in velocity and stride length attaining a maximum at intermediate friction levels. These data support a model of an unexplored mode of locomotion--"body-friction legged crawling" with body drag, friction-dominated leg thrust, but no media flow as in air, water, or sand. To define the limits of body compression in confined spaces, we conducted dynamic compressive cycle tests on living animals. Exoskeletal strength allowed cockroaches to withstand forces 300 times body weight when traversing the smallest crevices and up to nearly 900 times body weight without injury. Cockroach exoskeletons provided biological inspiration for the manufacture of an origami-style, soft, legged robot that can locomote rapidly in both open and confined spaces.

  4. Cockroaches traverse crevices, crawl rapidly in confined spaces, and inspire a soft, legged robot

    Science.gov (United States)

    Jayaram, Kaushik; Full, Robert J.

    2016-01-01

    Jointed exoskeletons permit rapid appendage-driven locomotion but retain the soft-bodied, shape-changing ability to explore confined environments. We challenged cockroaches with horizontal crevices smaller than a quarter of their standing body height. Cockroaches rapidly traversed crevices in 300–800 ms by compressing their body 40–60%. High-speed videography revealed crevice negotiation to be a complex, discontinuous maneuver. After traversing horizontal crevices to enter a vertically confined space, cockroaches crawled at velocities approaching 60 cm⋅s−1, despite body compression and postural changes. Running velocity, stride length, and stride period only decreased at the smallest crevice height (4 mm), whereas slipping and the probability of zigzag paths increased. To explain confined-space running performance limits, we altered ceiling and ground friction. Increased ceiling friction decreased velocity by decreasing stride length and increasing slipping. Increased ground friction resulted in velocity and stride length attaining a maximum at intermediate friction levels. These data support a model of an unexplored mode of locomotion—“body-friction legged crawling” with body drag, friction-dominated leg thrust, but no media flow as in air, water, or sand. To define the limits of body compression in confined spaces, we conducted dynamic compressive cycle tests on living animals. Exoskeletal strength allowed cockroaches to withstand forces 300 times body weight when traversing the smallest crevices and up to nearly 900 times body weight without injury. Cockroach exoskeletons provided biological inspiration for the manufacture of an origami-style, soft, legged robot that can locomote rapidly in both open and confined spaces. PMID:26858443

  5. Deflection and translation of a ray traversing an optical system, nodal rays and the optical axis

    Directory of Open Access Journals (Sweden)

    W. F. Harris

    2009-12-01

    Full Text Available Expressions are derived for the deflection and transverse translation of a ray as it traverses an arbitrary optical system.  The system may be astigmatic and have relatively decentred refracting elements.  The expressions are in terms of the fundamental properties of the system.  Because nodal rays are rays that undergo no deflection the results lead immediately to expressions that define nodal rays through the system.  An optical axis of an optical system is a nodal ray that is a straight line through the system.  This allows one to write an expression that determines the optical axis of an arbitrary optical system.

  6. Effects of Majorana physics on the UHE ν{sub τ} flux traversing the Earth

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Lucia [Universidad de la Republica, Instituto de Fisica, Facultad de Ingenieria, Montevideo (Uruguay); Romero, Ismael; Zapata, Gabriel; Sampayo, Oscar A. [Universidad Nacional de Mar del Plata, Instituto de Investigaciones Fisicas de Mar del Plata (IFIMAR), CONICET, UNMDP, Departamento de Fisica, Mar del Plata (Argentina)

    2017-02-15

    We study the effects produced by sterile Majorana neutrinos on the ν{sub τ} flux traversing the Earth, considering the interaction between the Majorana neutrinos and the standard matter as modeled by an effective theory. The surviving tau-neutrino flux is calculated using transport equations including Majorana neutrino production and decay. We compare our results with the pure Standard Model interactions, computing the surviving flux for different values of the effective lagrangian couplings, considering the detected flux by IceCube for an operation time of 10 years, and Majorana neutrinos with mass m{sub N} ∝ m{sub τ}. (orig.)

  7. Recognition of traversable areas for mobile robotic navigation in outdoor environments.

    Energy Technology Data Exchange (ETDEWEB)

    Hutchinson, Scott Alan (University of Illinois at Urbana-Champaign, Urbana, IL); Davidson, James C. (University of Illinois at Urbana-Champaign, Urbana, IL)

    2003-06-01

    In this paper we consider the problem of automatically determining whether regions in an outdoor environment can be traversed by a mobile robot. We propose a two-level classifier that uses data from a single color image to make this determination. At the low level, we have implemented three classifiers based on color histograms, directional filters and local binary patterns. The outputs of these low level classifiers are combined using a voting scheme that weights the results of each classifier using an estimate of its error probability. We present results from a large number of trials using a database of representative images acquired in real outdoor environments.

  8. On the propagation of sound waves in a stellar wind traversed by periodic strong shocks

    OpenAIRE

    Pijpers, F. P.

    1994-01-01

    It has been claimed that in stellar winds traversed by strong shocks the mechanism for driving the wind by sound wave pressure cannot operate because sound waves cannot propagate past the shocks. It is shown here that sound waves can propagate through shocks in one direction and that this is a sufficient condition for the sound wave pressure mechanism to work. A strong shock amplifies a sound wave passing through it and can drag the sound wave away from the star. It is immaterial for the soun...

  9. Traversable terrain classification for outdoor autonomous robots using single 2D laser scans

    DEFF Research Database (Denmark)

    Andersen, Jens Christian; Blas, Morten Rufus; Andersen, Nils Axel

    2006-01-01

    , curvature, slope, width and invalid data. These are then used to extract road borders, traversable terrain and identify obstacles. Experimental results are shown and discussed. The results were obtained using a DTU developed mobile robot, and the autonomous tests were conducted in a national park......Interpreting laser data to allow autonomous robot navigation on paved as well as dirt roads using a fixed angle 2D laser scanner is a daunting task. This paper introduces an algorithm for terrain classification that fuses seven distinctly different classifiers: raw height, roughness, step size...

  10. Rim Structure, Stratigraphy, and Aqueous Alteration Exposures Along Opportunity Rover's Traverse of the Noachian Endeavour Crater

    Science.gov (United States)

    Crumpler, L.S.; Arvidson, R. E.; Golombek, M.; Grant, J. A.; Jolliff, B. L.; Mittlefehldt, D. W.

    2017-01-01

    The Mars Exploration Rover Opportunity has traversed 10.2 kilometers along segments of the west rim of the 22-kilometer-diameter Noachian Endeavour impact crater as of sol 4608 (01/09/17). The stratigraphy, attitude of units, lithology, and degradation state of bedrock outcrops exposed on the crater rim have been examined in situ and placed in geologic context. Structures within the rim and differences in physical properties of the identified lithologies have played important roles in localizing outcrops bearing evidence of aqueous alteration.

  11. Predicting Long-Range Traversability from Short-Range Stereo-Derived Geometry

    Science.gov (United States)

    Turmon, Michael; Tang, Benyang; Howard, Andrew; Brjaracharya, Max

    2010-01-01

    Based only on its appearance in imagery, this program uses close-range 3D terrain analysis to produce training data sufficient to estimate the traversability of terrain beyond 3D sensing range. This approach is called learning from stereo (LFS). In effect, the software transfers knowledge from middle distances, where 3D geometry provides training cues, into the far field where only appearance is available. This is a viable approach because the same obstacle classes, and sometimes the same obstacles, are typically present in the mid-field and the farfield. Learning thus extends the effective look-ahead distance of the sensors.

  12. Análise do processo de tomada de consciência de professoras por meio do jogo Traverse Analysis of the teachers awareness process through Traverse game

    Directory of Open Access Journals (Sweden)

    Meire Andersan Fiorot

    2008-12-01

    Full Text Available Esta pesquisa teve por objetivo investigar, em uma perspectiva microgenética, o processo de tomada de consciência de quatro professoras, por meio de um jogo de regras. O procedimento de pesquisa foi organizado em duas fases: de instrução e de experimentação. Em ambas, foi utilizado o jogo Traverse. Vários questionamentos foram propostos de modo que as professoras pudessem refletir sobre as situações vividas no jogo. Os resultados constataram uma evolução nos níveis de compreensão do sistema lógico contido no jogo, com a existência de momentos intermediários que indicaram uma tomada de consciência parcial da ação. A principal dificuldade apresentada, nesse processo, foi a compreensão da dialética intersistêmica existente no jogo. Diante dessa constatação, sugerimos uma reflexão mais ampla sobre os contextos de aprendizagem que têm sido oferecidos aos professores em seus processos de formação, considerando que a profissionalização requer um trabalho de tomada de consciência sobre os próprios processos de aprendizagem.This research aims at investigating, in microgenetics perspective, the awareness process of four teachers through a rules game. The research procedure was organized into two stages: the instruction and experiment. In both of them the Traverse game was used. A lot of questions were offered so that the teachers could make reflections about the situations experienced in the game. The results showed an evolution in the comprehension levels of the logical system of the game, with intermediate moments that indicated a parcial awareness of the action. The main difficulty in this process was the comprehension of the intersystemic dialectics of the game. Faced with this evidence, we suggest a deeper reflection about the learning contexts wich have been offered to the teachers in their instructional processes, considering that ones's profissionalization requires a careful awareness process about his particular

  13. Shallow PS-logging by high frequency wave; Koshuha wo mochiita senbu PS kenso

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, A.; Miyazawa, M.; Azuma, H. [OYO Corp., Tokyo (Japan)

    1996-05-01

    This paper describes the following matters on down-hole PS logging in shallow subsurface. Determining an elastic wave velocity structure in shallow subsurface with high accuracy by using down-hole PS logging requires reduction of errors in reading travel time. Therefore, a high-frequency vibration source was fabricated with an objective to raise frequencies of waves used for the measurement. Measurements were made on two holes, A and B, at a measurement interval of 0.5 m, whereas at the hole A a measurement was performed simultaneously by using a normal type (low-frequency) vibration source. A spectral analysis on the waveform record revealed that the frequencies with each vibration source were 127 Hz and 27 Hz for the hole A, 115 Hz for the hole B, and the S/N ratio was all the same for both holes. When the high-frequency vibration source was used, the velocity was determined at accuracy of 5% over the whole length of the shallow section. When the low-frequency vibration source was used, sections with the velocity determining error greater than 5% were found, and it was not possible to derive the velocity structure in the shallow subsurface in fine segments. 3 refs., 8 figs., 2 tabs.

  14. Emotions in freely varying and mono-pitched vowels, acoustic and EGG analyses.

    Science.gov (United States)

    Waaramaa, Teija; Palo, Pertti; Kankare, Elina

    2015-12-01

    Vocal emotions are expressed either by speech or singing. The difference is that in singing the pitch is predetermined while in speech it may vary freely. It was of interest to study whether there were voice quality differences between freely varying and mono-pitched vowels expressed by professional actors. Given their profession, actors have to be able to express emotions both by speech and singing. Electroglottogram and acoustic analyses of emotional utterances embedded in expressions of freely varying vowels [a:], [i:], [u:] (96 samples) and mono-pitched protracted vowels (96 samples) were studied. Contact quotient (CQEGG) was calculated using 35%, 55%, and 80% threshold levels. Three different threshold levels were used in order to evaluate their effects on emotions. Genders were studied separately. The results suggested significant gender differences for CQEGG 80% threshold level. SPL, CQEGG, and F4 were used to convey emotions, but to a lesser degree, when F0 was predetermined. Moreover, females showed fewer significant variations than males. Both genders used more hypofunctional phonation type in mono-pitched utterances than in the expressions with freely varying pitch. The present material warrants further study of the interplay between CQEGG threshold levels and formant frequencies, and listening tests to investigate the perceptual value of the mono-pitched vowels in the communication of emotions.

  15. A Freely-Available Authoring System for Browser-Based CALL with Speech Recognition

    Science.gov (United States)

    O'Brien, Myles

    2017-01-01

    A system for authoring browser-based CALL material incorporating Google speech recognition has been developed and made freely available for download. The system provides a teacher with a simple way to set up CALL material, including an optional image, sound or video, which will elicit spoken (and/or typed) answers from the user and check them…

  16. Hippocampal activity during transient respiratory events in the freely behaving cat

    DEFF Research Database (Denmark)

    Poe, G R; Kristensen, Morten Pilgaard; Rector, D M

    1996-01-01

    We measured dorsal hippocampal activity accompanying sighs and apnea using reflectance imaging and electrophysiologic measures in freely behaving cats. Reflected 660-nm light from a 1-mm2 area of CA1 was captured during sighs and apnea at 25 Hz through a coherent image conduit coupled to a charge...

  17. "Just Google It"--The Scope of Freely Available Information Sources for Doctoral Thesis Writing

    Science.gov (United States)

    Grigas, Vincas; Juzeniene, Simona; Velickaite, Jone

    2017-01-01

    Introduction: Recent developments in the field of scientific information resource provision lead us to the key research question, namely,what is the coverage of freely available information sources when writing doctoral theses, and whether the academic library can assume the leading role as a direct intermediator for information users. Method:…

  18. 3D-e-Chem-VM : Structural Cheminformatics Research Infrastructure in a Freely Available Virtual Machine

    NARCIS (Netherlands)

    McGuire, Ross; Verhoeven, Stefan; Vass, Márton; Vriend, Gerrit; De Esch, Iwan J P; Lusher, Scott J.; Leurs, Rob; Ridder, Lars; Kooistra, Albert J.; Ritschel, Tina; de Graaf, C.

    2017-01-01

    3D-e-Chem-VM is an open source, freely available Virtual Machine ( http://3d-e-chem.github.io/3D-e-Chem-VM/ ) that integrates cheminformatics and bioinformatics tools for the analysis of protein-ligand interaction data. 3D-e-Chem-VM consists of software libraries, and database and workflow tools

  19. A lightweight telemetry system for recording neuronal activity in freely behaving small animals

    NARCIS (Netherlands)

    Schregardus, D.S.; Pieneman, A.W.; ter Maat, A.; Brouwer, T.J.F.; Gahr, M.L.

    2006-01-01

    A miniature lightweight radio telemetric device is described which is shown to be suitable for recording neuronal activity in freely behaving animals. Its size (12 × 5 × 8 mm) and weight (1.0-1.1 g with batteries, 0.4-0.5 g without) make the device particularly suitable for recording neuronal units

  20. Mars exploration rover geologic traverse by the spirit rover in the plains of Gusev crater, Mars

    Science.gov (United States)

    Crumpler, L.S.; Squyres, S. W.; Arvidson, R. E.; Bell, J.F.; Blaney, D.; Cabrol, N.A.; Christensen, P.R.; DesMarais, D.J.; Farmer, J.D.; Fergason, R.; Golombek, M.P.; Grant, F.D.; Grant, J. A.; Greeley, R.; Hahn, B.; Herkenhoff, K. E.; Hurowitz, J.A.; Knudson, A.T.; Landis, G.A.; Li, R.; Maki, J.; McSween, H.Y.; Ming, D. W.; Moersch, J.E.; Payne, M.C.; Rice, J.W.; Richter, L.; Ruff, S.W.; Sims, M.; Thompson, S.D.; Tosca, N.; Wang, A.; Whelley, P.; Wright, S.P.; Wyatt, M.B.

    2005-01-01

    The Spirit rover completed a 2.5 km traverse across gently sloping plains on the floor of Gusev crater from its location on the outer rim of Bonneville crater to the lower slopes of the Columbia Hills, Mars. Using the Athena suite of instruments in a transect approach, a systematic series of overlapping panoramic mosaics, remote sensing observations, surface analyses, and trenching operations documented the lateral variations in landforms, geologic materials, and chemistry of the surface throughout the traverse, demonstrating the ability to apply the techniques of field geology by remote rover operations. Textures and shapes of rocks within the plains are consistent with derivation from impact excavation and mixing of the upper few meters of basaltic lavas. The contact between surrounding plains and crater ejecta is generally abrupt and marked by increases in clast abundance and decimeter-scale steps in relief. Basaltic materials of the plains overlie less indurated and more altered rock types at a time-stratigraphic contact between the plains and Columbia Hills that occurs over a distance of one to two meters. This implies that regional geologic contacts are well preserved and that Earth-like field geologic mapping will be possible on Mars despite eons of overturn by small impacts. ?? 2005 Geological Society of America.

  1. Traversing the Cell: Agrobacterium T-DNA’s Journey to the Host Genome

    Science.gov (United States)

    Gelvin, Stanton B.

    2012-01-01

    The genus Agrobacterium is unique in its ability to conduct interkingdom genetic exchange. Virulent Agrobacterium strains transfer single-strand forms of T-DNA (T-strands) and several Virulence effector proteins through a bacterial type IV secretion system into plant host cells. T-strands must traverse the plant wall and plasma membrane, traffic through the cytoplasm, enter the nucleus, and ultimately target host chromatin for stable integration. Because any DNA sequence placed between T-DNA “borders” can be transferred to plants and integrated into the plant genome, the transfer and intracellular trafficking processes must be mediated by bacterial and host proteins that form complexes with T-strands. This review summarizes current knowledge of proteins that interact with T-strands in the plant cell, and discusses several models of T-complex (T-strand and associated proteins) trafficking. A detailed understanding of how these macromolecular complexes enter the host cell and traverse the plant cytoplasm will require development of novel technologies to follow molecules from their bacterial site of synthesis into the plant cell, and how these transferred molecules interact with host proteins and sub-cellular structures within the host cytoplasm and nucleus. PMID:22645590

  2. Overview of the Moral Status of iPS Cells.

    Science.gov (United States)

    Martinho, Andreia Martins

    2016-07-01

    The production of induced pluripotent stem (iPS) cells in 2006 by Takahashi and Yamanaka was a major breakthrough in stem cell research. IPS cells technology holds great promise for cell therapy, disease modelling, and drug testing, but it poses ethical questions concerning the moral status of somatic cells, which can re-gain pluripotency (iPS cells). This article provides an overview of the arguments that substantiate the debate on the moral assessment of iPS cells: potentiality argument; relational properties/standard view; and genetic basis for moral status.

  3. New safety training for access to the PS complex areas

    CERN Multimedia

    2012-01-01

    Since 10/08/2012, a new course dedicated to the specific radiological risks in the accelerators of the PS complex has been available on SIR (https://sir.cern.ch/). This course complements the general classroom-based Radiation Safety training. Successful completion of the course will be obligatory and verified by the access system as from 01/11/2012 for access to the following accelerator areas: LINAC2, BOOSTER, PS and TT2. Information and reminder e-mails will be sent to all persons currently authorized to access the accelerators of the PS complex. For questions please contact the HSE unit and in particular, the Radiation Protection Group (+41227672504 or safety-rp-ps-complex@cern.ch).

  4. Determination of slope safety factor with analytical solution and searching critical slip surface with genetic-traversal random method.

    Science.gov (United States)

    Niu, Wen-jie

    2014-01-01

    In the current practice, to determine the safety factor of a slope with two-dimensional circular potential failure surface, one of the searching methods for the critical slip surface is Genetic Algorithm (GA), while the method to calculate the slope safety factor is Fellenius' slices method. However GA needs to be validated with more numeric tests, while Fellenius' slices method is just an approximate method like finite element method. This paper proposed a new method to determine the minimum slope safety factor which is the determination of slope safety factor with analytical solution and searching critical slip surface with Genetic-Traversal Random Method. The analytical solution is more accurate than Fellenius' slices method. The Genetic-Traversal Random Method uses random pick to utilize mutation. A computer automatic search program is developed for the Genetic-Traversal Random Method. After comparison with other methods like slope/w software, results indicate that the Genetic-Traversal Random Search Method can give very low safety factor which is about half of the other methods. However the obtained minimum safety factor with Genetic-Traversal Random Search Method is very close to the lower bound solutions of slope safety factor given by the Ansys software.

  5. Study of Value Co-Creation in CoPS

    OpenAIRE

    Mingli Zhang; Jianhua Ye

    2013-01-01

    Value co-creation is associated with specific investment in the context of CoPS. The feature of CoPS decides that the study of co-creation cannot execute without regarding asset specificity. This study considers that value co-creation will be associated with specific value, which is outcome of relationship value and asset specificity. Supplier and customer have a close relation, which conducts to specific investment and then it turns to obstacle for competitors. Trust, commitment and satisfac...

  6. Motor-generator set of the PS main supply

    CERN Multimedia

    Photographic Service; CERN PhotoLab

    1968-01-01

    Already in 1964, the PS improvement programme included a new main magnet supply with more power for the longer cycles needed for slow extraction at the full energy of 26 GeV. This motor-generator set was installed in 1967 and took up service at the beginning of 1968. Regularly serviced and fitted with modern electronic regulation, it pulses the PS to this day.

  7. The Libera as a PS orbit measurement system building block

    CERN Document Server

    Belleman, J M; CERN. Geneva. AB Department

    2005-01-01

    During the year 2004, extensive tests using a Libera data processor have been made in order to study its suitability as a building block for a complete PS trajectory and orbit measurement system. The Libera consists of four fast 12-bits ADCs, a Virtex II Pro FPGA and a large memory. This note presents some of the results of the analysis of acquisitions made on a position pick-up in the CERN PS.

  8. DiPS: A Unifying Approach for developing System Software

    OpenAIRE

    Michiels, Sam; Matthijs, Frank; Walravens, Dirk; Verbaeten, Pierre

    2002-01-01

    In this paper we unify three essential features for flexible system software: a component oriented approach, self-adaptation and separation of concerns.We propose DiPS (Distrinet Protocol Stack), a component framework, which offers components, an anonymous interaction model and connectors to handle non-functional aspects such as concurrency. DiPS has effectively been used in industrial protocol stacks and device drivers.

  9. The new heart of the PS is beating strongly

    CERN Document Server

    Corinne Pralavorio

    2011-01-01

    The PS has resumed operation with a brand new electrical power system called POPS; this enormous system comprising power electronics and capacitors is crucial because if it broke down practically no particles would be able to circulate at CERN. As soon as it started, POPS passed all the tests with flying colours and is now pulsing at full power.   The new PS power system is made up of 6 containers, each with 60 tonnes of capacitors and 8 power converters. The date 11/02/11 will always be remembered with affection by the engineers in the Electrical Power Converters Group. At 11:11 in the morning (no joke), the first beams powered by the new system began to circulate in the PS. The cutely-named POPS (POwer for PS) took over from the old rotating machine that had been working since 1968. From now on it will be POPS that supplies the PS main magnets with the electrical pulses needed to accelerate the beams for the LHC and all CERN's other facilities. The system is crucial as the PS is one of the lyn...

  10. The PS will soon be back in operation

    CERN Multimedia

    2006-01-01

    The PS's power supply system is undergoing repairs for the accelerator to restart on 26 June. The AB Department's Power Converter Group is working flat out with Siemens to return the PS's power supply system to working order. A problem appeared on the insulation of the power cables of the rotor of the rotating machine (photo) which supplies power to the PS magnets. To prevent more significant damage to the rotating machine, the AB Department, with the approval of the CERN Management, decided to shut down the PS which had started running on 15 May. Everything is being done to restart the accelerator on 26 June. The PS's rotating machine comprises a motor coupled to a generator. The generator's rotor acts like a flywheel, supplying high-power pulses of 40 to 50 megawatts to the PS magnets. The 6 megawatt motor drives the installation at 1000 revolutions per minute and compensates only for variations in speed. It is an essential interface since it would be hard to imagine connecting such an electrical charge, p...

  11. iPS-Cinderella Story in Cell Biology

    Directory of Open Access Journals (Sweden)

    Editorial

    2010-01-01

    Full Text Available As we step through the frontiers of modern Science, we are all witnesses to the Cinderella story repeating itself in the form of the iPS. The process of re-programming adult somatic cells to derive Induced Pluripotent stem cells (iPS with the wand of transcription factors and then differentiating them back to adult somatic cells resembles the transformation of Cinderella from a Cinder girl to princess and back to a Cinder girl after the ball; but the iPS-Cinderella is the most fascinating thing ever in cell biology!From the day iPS first made its headlines when it was first produced by Shinya Yamanaka at Kyoto University in Japan, Stem Cell scientists all over the world are re- doing their experiments so far done using other sources like embryonic and adult Stem cells with the iPS cells exploring their potential to the fullest. A Stem Cell science news page without this magic word of iPS is difficult to imagine these days and Scientists have been successful in growing most of the adult Cell types from iPS cells.iPS cells was the key to solve the problems of Immune rejection and Immunosupression required when using other allogeneic Stem cell types which had baffled scientists previously. But the issues raised by scientists about the use of viruses and Oncogenes in producing iPS cells were made groundless when scientists in February 2008 published the discovery of a technique that could remove oncogenes after the induction of pluripotency and now it is possible to induce pluripotency using plasmid transfection, piggyback transposon system and piggyback transposon system combined with a non viral vector system. The word of the day is pIPS which are protein-induced Pluripotent stem cells which are iPS cells that were generated without any genetic alteration of the adult cell. This research by the group of Sheng Ding in La Jolla, California made public in April 2009 showed that the generation of poly-arginine anchors was sufficient to induce

  12. Simulation of a wide area survey for NEOs with Pan-STARRS PS1 & PS2 Telescopes

    Science.gov (United States)

    Chambers, Kenneth C.; Lilly (Schunova), Eva; Dukes, Martin Todd; Wainscoat, Richard J.

    2017-10-01

    We have performed a new survey simulation for a wide area survey with PS1 & PS2 as part of our quest to optimize the discovery rate of Near Earth Objects with the full Pan-STARRS system. The survey is intended to be as unbiased and as complete as possible given the available sky visibility and the anticipated performance of the PS1 and PS2 telescopes working together. The simulation includes a complete model of both telescopes, camera and slew overhead, sky visibility, moon phase, galactic plane exclusion, and weather. The performance of the resulting survey strategy is then evaluated using the method of Lilly et. al. 2017. This uses the Greenstreet et al. 2012 model with 50 million NEOs with absolute magnitudes 13 < H < 29 and the Moving Object Processing System (MOPS, Denneau et al. 2013) for linkages. The results are compared with other possible strategies.

  13. Exotica ex nihilo: Traversable wormholes & non-singular black holes from the vacuum of quadratic gravity

    CERN Document Server

    Duplessis, Francis

    2015-01-01

    We present new traversable wormhole and non-singular black hole solutions in pure, scale-free $R^2$ gravity. These exotic solutions require no null energy condition violating or "exotic" matter and are supported only by the vacuum of the theory. It is well known that $f(R)$ theories of gravity may be recast as dual theories in the Einstein frame. The solutions we present are found when the conformal transformation required to move to the dual frame is singular. In the specific case of purely quadratic $R^2$ gravity, the required conformal factor is identically zero for spacetimes with $R=0$. Solutions in this case are argued to arise in the strong coupling limit of General Relativity.

  14. Proceedings 3rd Workshop on GRAPH Inspection and Traversal Engineering (GRAPHITE 2014)

    DEFF Research Database (Denmark)

    2014-01-01

    These are the proceedings of the Third Workshop on GRAPH Inspection and Traversal Engineering (GRAPHITE 2014), which took place on April 5, 2014 in Grenoble, France, as a satellite event of the 17th European Joint Conferences on Theory and Practice of Software (ETAPS 2014). The aim of GRAPHITE...... is to foster the convergence on research interests from several communities dealing with graph analysis in all its forms in computer science, with a particular attention to software development and analysis. Graphs are used to represent data and processes in many application areas, and they are subjected...... to various computational algorithms in order to analyze them. Just restricting the attention to the analysis of software, graph analysis algorithms are used, for instance, to verify properties using model checking techniques that explore the system's state space graph or static analysis techniques based...

  15. Water resources of the Lake Traverse Reservation, South and North Dakota, and Roberts County, South Dakota

    Science.gov (United States)

    Thompson, Ryan F.

    2001-01-01

    In 1994, the U.S. Geological Survey, in cooperation with the Sisseton-Wahpeton Sioux Tribe; Roberts County; and the South Dakota Department of Environment and Natural Resources, Geological Survey Program, began a 6-year investigation to describe and quantify the water resources of the area within the 1867 boundary of the Lake Traverse Reservation and adjacent parts of Roberts County. Roberts County is located in extreme northeastern South Dakota, and the 1867 boundary of the Lake Traverse Reservation encompasses much of Roberts County and parts of Marshall, Day, Codington, and Grant Counties in South Dakota and parts of Richland and Sargent Counties in southeast North Dakota. This report includes descriptions of the quantity, quality, and availability of surface and ground water, the extent of the major glacial and bedrock aquifers and named outwash groups, and surface- and ground-water uses within the 1867 boundary of the Lake Traverse Reservation and adjacent parts of Roberts County. The surface-water resources within the 1867 boundary of the Lake Traverse Reservation and adjacent parts of Roberts County include rivers, streams, lakes, and wetlands. The Wild Rice and Bois de Sioux Rivers are tributaries of the Red River within the Souris-Red-Rainy River Basin; the Little Minnesota, Jorgenson, and North Fork Whetstone Rivers are tributaries of the Minnesota River within the Upper Mississippi River Basin, and the James and Big Sioux Rivers are tributaries within the Missouri River Basin. Several of the larger lakes within the study area have been developed for recreation, while many of the smaller lakes and wetlands are used for livestock watering or as wildlife production areas. Statistical summaries are presented for the water-quality data of six selected streams within the study area, and the dominant chemical species are listed for 17 selected lakes within the study area. The glacial history of the study area has led to a rather complex system of glacial

  16. Dynamic response of arch bridges traversed by high-speed trains

    Science.gov (United States)

    Lacarbonara, Walter; Colone, Valerio

    2007-07-01

    A mechanical model describing the planar elasto-dynamics of arch bridges with general arch profiles is presented. The model is amenable to analytical or semi-analytical treatments and is effective for parametric studies, design of control systems or structural optimizations. The Ritz's energy approach is employed to calculate the solutions of the vibration eigenvalue problem—natural frequencies and mode shapes—and the forced responses to external excitations, namely those induced by the passage of trains. A closed-form solution of the bridge dynamic response to the transit of trains with arbitrary load distributions and running speeds is found and the train-induced resonances are accordingly discussed. In particular, three European high-speed trains—the French TGV, the Italian ETR 500, and the German ICE—traversing a lower-deck steel arch bridge are considered and the ensuing responses are investigated.

  17. Identifying time measurement tampering in the traversal time and hop count analysis (TTHCA) wormhole detection algorithm.

    Science.gov (United States)

    Karlsson, Jonny; Dooley, Laurence S; Pulkkis, Göran

    2013-05-17

    Traversal time and hop count analysis (TTHCA) is a recent wormhole detection algorithm for mobile ad hoc networks (MANET) which provides enhanced detection performance against all wormhole attack variants and network types. TTHCA involves each node measuring the processing time of routing packets during the route discovery process and then delivering the measurements to the source node. In a participation mode (PM) wormhole where malicious nodes appear in the routing tables as legitimate nodes, the time measurements can potentially be altered so preventing TTHCA from successfully detecting the wormhole. This paper analyses the prevailing conditions for time tampering attacks to succeed for PM wormholes, before introducing an extension to the TTHCA detection algorithm called ∆T Vector which is designed to identify time tampering, while preserving low false positive rates. Simulation results confirm that the ∆T Vector extension is able to effectively detect time tampering attacks, thereby providing an important security enhancement to the TTHCA algorithm.

  18. Identifying Time Measurement Tampering in the Traversal Time and Hop Count Analysis (TTHCA Wormhole Detection Algorithm

    Directory of Open Access Journals (Sweden)

    Jonny Karlsson

    2013-05-01

    Full Text Available Traversal time and hop count analysis (TTHCA is a recent wormhole detection algorithm for mobile ad hoc networks (MANET which provides enhanced detection performance against all wormhole attack variants and network types. TTHCA involves each node measuring the processing time of routing packets during the route discovery process and then delivering the measurements to the source node. In a participation mode (PM wormhole where malicious nodes appear in the routing tables as legitimate nodes, the time measurements can potentially be altered so preventing TTHCA from successfully detecting the wormhole. This paper analyses the prevailing conditions for time tampering attacks to succeed for PM wormholes, before introducing an extension to the TTHCA detection algorithm called ∆T Vector which is designed to identify time tampering, while preserving low false positive rates. Simulation results confirm that the ∆T Vector extension is able to effectively detect time tampering attacks, thereby providing an important security enhancement to the TTHCA algorithm.

  19. A New MANET wormhole detection algorithm based on traversal time and hop count analysis.

    Science.gov (United States)

    Karlsson, Jonny; Dooley, Laurence S; Pulkkis, Göran

    2011-01-01

    As demand increases for ubiquitous network facilities, infrastructure-less and self-configuring systems like Mobile Ad hoc Networks (MANET) are gaining popularity. MANET routing security however, is one of the most significant challenges to wide scale adoption, with wormhole attacks being an especially severe MANET routing threat. This is because wormholes are able to disrupt a major component of network traffic, while concomitantly being extremely difficult to detect. This paper introduces a new wormhole detection paradigm based upon Traversal Time and Hop Count Analysis (TTHCA), which in comparison to existing algorithms, consistently affords superior detection performance, allied with low false positive rates for all wormhole variants. Simulation results confirm that the TTHCA model exhibits robust wormhole route detection in various network scenarios, while incurring only a small network overhead. This feature makes TTHCA an attractive choice for MANET environments which generally comprise devices, such as wireless sensors, which possess a limited processing capability.

  20. A New MANET Wormhole Detection Algorithm Based on Traversal Time and Hop Count Analysis

    Directory of Open Access Journals (Sweden)

    Göran Pulkkis

    2011-11-01

    Full Text Available As demand increases for ubiquitous network facilities, infrastructure-less and self-configuring systems like Mobile Ad hoc Networks (MANET are gaining popularity. MANET routing security however, is one of the most significant challenges to wide scale adoption, with wormhole attacks being an especially severe MANET routing threat. This is because wormholes are able to disrupt a major component of network traffic, while concomitantly being extremely difficult to detect. This paper introduces a new wormhole detection paradigm based upon Traversal Time and Hop Count Analysis (TTHCA, which in comparison to existing algorithms, consistently affords superior detection performance, allied with low false positive rates for all wormhole variants. Simulation results confirm that the TTHCA model exhibits robust wormhole route detection in various network scenarios, while incurring only a small network overhead. This feature makes TTHCA an attractive choice for MANET environments which generally comprise devices, such as wireless sensors, which possess a limited processing capability.

  1. Defining Long-Duration Traverses of Lunar Volcanic Complexes with LROC NAC Images

    Science.gov (United States)

    Stopar, J. D.; Lawrence, S. J.; Joliff, B. L.; Speyerer, E. J.; Robinson, M. S.

    2016-01-01

    A long-duration lunar rover [e.g., 1] would be ideal for investigating large volcanic complexes like the Marius Hills (MH) (approximately 300 x 330 km), where widely spaced sampling points are needed to explore the full geologic and compositional variability of the region. Over these distances, a rover would encounter varied surface morphologies (ranging from impact craters to rugged lava shields), each of which need to be considered during the rover design phase. Previous rovers including Apollo, Lunokhod, and most recently Yutu, successfully employed pre-mission orbital data for planning (at scales significantly coarser than that of the surface assets). LROC was specifically designed to provide mission-planning observations at scales useful for accurate rover traverse planning (crewed and robotic) [2]. After-the-fact analyses of the planning data can help improve predictions of future rover performance [e.g., 3-5].

  2. Adaptation of Escherichia coli traversing from the faecal environment to the urinary tract

    DEFF Research Database (Denmark)

    Nielsen, Karen L.; Stegger, Marc; Godfrey, Paul A.

    2016-01-01

    The majority of extraintestinal pathogenic Escherichia coli (ExPEC) causing urinary tract infections (UTI) are found in the patient’s own gut flora, but only limited knowledge is available on the potential adaptation that may occur in the bacteria in order to traverse the perineum and successfully......-synonymous mutations (0–12 substitutions in each pair) were primarily associated to genes encoding virulence factors and nutrient metabolism; and indications of parallel evolution were observed in genes encoding the major phase-variable protein antigen 43, a toxin/antitoxin locus and haemolysin B. No differences...... in virulence potential were observed in a mouse UTI model for five matching faecal and UTI isolates with or without mutations in antigen 43 and haemolysin B. Variations in plasmid content were observed in only four of the 42 pairs. Although, we observed mutations in known UTI virulence genes for a few pairs...

  3. Traversing every edge in each direction once, but not at once: Cubic (polyhedral graphs

    Directory of Open Access Journals (Sweden)

    Vladimir R. Rosenfeld

    2017-04-01

    Full Text Available A {\\em retracting-free bidirectional circuit} in a graph $G$ is a closed walk which traverses every edge exactly once in each direction and such that no edge is succeeded by the same edge in the opposite direction. Such a circuit revisits each vertex only in a number of steps. Studying the class $\\mathit{\\Omega}$ of all graphs admitting at least one retracting-free bidirectional circuit was proposed by Ore (1951 and is by now of practical use to nanotechnology. The latter needs in various molecular polyhedra that are constructed from a single chain molecule in the retracting-free way. Some earlier results for simple graphs, obtained by Thomassen and, then, by other authors, are specially refined by us for a cubic graph $Q$. Most of such refinements depend only on the number $n$ of vertices of $Q$.

  4. Profiling the microRNA Expression in Human iPS and iPS-derived Retinal Pigment Epithelium.

    Science.gov (United States)

    Wang, Heuy-Ching; Greene, Whitney A; Kaini, Ramesh R; Shen-Gunther, Jane; Chen, Hung-I H; Cai, Hong; Wang, Yufeng

    2014-01-01

    The purpose of this study is to characterize the microRNA (miRNA) expression profiles of induced pluripotent stem (iPS) cells and retinal pigment epithelium (RPE) derived from induced pluripotent stem cells (iPS-RPE). MiRNAs have been demonstrated to play critical roles in both maintaining pluripotency and facilitating differentiation. Gene expression networks accountable for maintenance and induction of pluripotency are linked and share components with those networks implicated in oncogenesis. Therefore, we hypothesize that miRNA expression profiling will distinguish iPS cells from their iPS-RPE progeny. To identify and analyze differentially expressed miRNAs, RPE was derived from iPS using a spontaneous differentiation method. MiRNA microarray analysis identified 155 probes that were statistically differentially expressed between iPS and iPS-RPE cells. Up-regulated miRNAs including miR-181c and miR-129-5p may play a role in promoting differentiation, while down-regulated miRNAs such as miR-367, miR-18b, and miR-20b are implicated in cell proliferation. Subsequent miRNA-target and network analysis revealed that these miRNAs are involved in cellular development, cell cycle progression, cell death, and survival. A systematic interrogation of temporal and spatial expression of iPS-RPE miRNAs and their associated target mRNAs will provide new insights into the molecular mechanisms of carcinogenesis, eye differentiation and development.

  5. Behavior of a test gyroscope moving towards a rotating traversable wormhole

    Science.gov (United States)

    Chakraborty, Chandrachur; Pradhan, Parthapratim

    2017-03-01

    The geodesic structure of the Teo wormhole is briefly discussed and some observables are derived that promise to be of use in detecting a rotating traversable wormhole indirectly, if it does exist. We also deduce the exact Lense-Thirring (LT) precession frequency of a test gyroscope moving toward a rotating traversable Teo wormhole. The precession frequency diverges on the ergoregion, a behavior intimately related to and governed by the geometry of the ergoregion, analogous to the situation in a Kerr spacetime. Interestingly, it turns out that here the LT precession is inversely proportional to the angular momentum (a) of the wormhole along the pole and around it in the strong gravity regime, a behavior contrasting with its direct variation with a in the case of other compact objects. In fact, divergence of LT precession inside the ergoregion can also be avoided if the gyro moves with a non-zero angular velocity in a certain range. As a result, the spin precession frequency of the gyro can be made finite throughout its whole path, even very close to the throat, during its travel to the wormhole. Furthermore, it is evident from our formulation that this spin precession not only arises due to curvature or rotation of the spacetime but also due to the non-zero angular velocity of the spin when it does not move along a geodesic in the strong gravity regime. If in the future, interstellar travel indeed becomes possible through a wormhole or at least in its vicinity, our results would prove useful in determining the behavior of a test gyroscope which is known to serve as a fundamental navigation device.

  6. The role of photogeologic mapping in traverse planning: lessons learned from DRATS 2010 activities

    Science.gov (United States)

    Skinner, James A.; Fortezzo, Corey M.

    2013-01-01

    We produced a 1:24,000 scale photogeologic map of the Desert Research and Technology Studies (DRATS) 2010 simulated lunar mission traverse area and surrounding environments located within the northeastern part of the San Francisco Volcanic Field (SFVF), north-central Arizona. To mimic an exploratory mission, we approached the region "blindly" by rejecting prior knowledge or preconceived notions of the regional geologic setting and focused instead only on image and topographic base maps that were intended to be equivalent to pre-cursor mission "orbital returns". We used photogeologic mapping techniques equivalent to those employed during the construction of modern planetary geologic maps. Based on image and topographic base maps, we identified 4 surficial units (talus, channel, dissected, and plains units), 5 volcanic units (older cone, younger cone, older flow, younger flow, and block field units), and 5 basement units (grey-toned mottled, red-toned platy, red-toned layered, light-toned slabby, and light-toned layered units). Comparison of our remote-based map units with published field-based map units indicates that the two techniques yield pervasively similar results of contrasting detail, with higher accuracies linked to remote-based units that have high topographic relief and tonal contrast relative to adjacent units. We list key scientific questions that remained after photogeologic mapping and prior to DRATS activities and identify 13 specific observations that the crew and science team would need to make in order to address those questions and refine the interpreted geologic context. We translated potential observations into 62 recommended sites for visitation and observation during the mission traverse. The production and use of a mission-specific photogeologic map for DRATS 2010 activities resulted in strategic and tactical recommendations regarding observational context and hypothesis tracking over the course of an exploratory mission.

  7. The jury and assessment of evidence based on freely judicial beliefs

    Directory of Open Access Journals (Sweden)

    Bugarski Tatjana

    2014-01-01

    Full Text Available In modern criminal procedural legislation, the great attention is paid to the issue of collecting evidence i.e. evidentiary actions as one of the most important issues of criminal proceedings. In most cases, the processing and analysis of this issue comes down to conditions for the application of evidentiary actions, proceedings authorities, the manner of their performance etc. However, the question of the assessment of evidence based on freely judicial beliefs remains as one of the most important questions concerning evidentiary actions, which has an impact on the outcome of the proceedings and the court's decision. This issue is particularly important when one takes into account the existence of the court traditional laic elements within the general criminal proceedings. Therefore the subject of this paper is the assessment of evidence based on juror's freely judicial beliefs, their role in criminal proceedings, their powers and competences, as well as the question of justification of their participation in criminal proceedings.

  8. Autonomous Head-mounted Electrophysiology Systems for Freely-Behaving Primates

    OpenAIRE

    Gilja, Vikash; Chestek, Cindy A.; Nuyujukian, Paul; Foster, Justin; Shenoy, Krishna V.

    2010-01-01

    Recent technological advances have led to new lightweight battery-operated systems for electrophysiology. Such systems are head mounted, run for days without experimenter intervention, and can record and stimulate from single or multiple electrodes implanted in a freely-behaving primates. Here we discuss existing systems, studies that use them, and how they can augment traditional, physically restrained, “in-rig” electrophysiology. With existing technical capabilities these systems can acquir...

  9. An Arbitrary Waveform Wearable Neuro-stimulator System for Neurophysiology Research on Freely Behaving Animals

    OpenAIRE

    Samani, Mohsen Mosayebi; Mahnam, Amin; HOSSEINI, Nasrin

    2014-01-01

    Portable wireless neuro-stimulators have been developed to facilitate long-term cognitive and behavioral studies on the central nervous system in freely moving animals. These stimulators can provide precisely controllable input(s) to the nervous system, without distracting the animal attention with cables connected to its body. In this study, a low power backpack neuro-stimulator was developed for animal brain researches that can provides arbitrary stimulus waveforms for the stimulation, whil...

  10. Preoperative diagnosis and radiographic findings of a freely movable mucocele of the vermiform appendix

    Energy Technology Data Exchange (ETDEWEB)

    Shukunami, K.-I.; Kaneshima, M.; Kotsuji, F. [Fukui Medical Univ., Dept. of Obstetrics and Gynecology, Matsuoka-Cho, Yoshida-Gun, Fukui (Japan)

    2000-10-01

    Mucocele of the vermiform appendix is rarely diagnosed before surgery, although radiologic and ultrasonographic (US) findings have been reported. To our knowledge, there have been no previous reports of 2 different radiologic images of the cyst in the same patient during the preoperative period. We present 2 different shapes and locations of a freely movable mucocele of the appendix as it appeared before surgery. (author)

  11. Characterization of crosslinked polystyrene(PS) beads in SBR matrix

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Yoon-Jong; Choe, Soonja [Inha Univ. (Korea, Republic of)

    1995-12-01

    Monodisperse sized crosslinked polystyrene(PS) beads were prepared by a reaction of semibatch emulsion polymerization with styrene monomer, divinylbenzene(DVB) crosslinking agent and potassium persulfate(K{sub 2}S{sub 2}O{sub 9}) initiator in the absence of emulsifier. The glass transition temperature(T{sub g}) and the mean diameter of the beads were increased from 100{degrees}C to 135{degrees}C and from 402 nm to 532 nm, respectively, for an incorporation of 2 to 10 mol% DVB. Crosslinking density was also linearly increased with DVB content. SEM microphotographs of SBR composite filled with various contents of PS beads revealed that PS beads are relatively well dispersed without changing the spherical shape of the beads in all range of compositions. In stress-strain analysis, elongation at break and tensile strength of SBR composite were increased with the bead content. Applicability of the PS beads as a filler in SBR matrix is tested by plotting Mooney-Rivlin or Guth-Smallwood equations. However, mechanical properties of the composite with the beads were not so excellent as those of the composite with carbon black. Crosslinked PS beads are still tentative as a white color reinforcing filler on SBR matrix.

  12. The PS complex produces the nominal LHC beam

    CERN Document Server

    Benedikt, Michael; Borburgh, J; Cappi, R; Chanel, M; Chohan, V; Cyvoct, G; Garoby, R; Grier, D G; Gruber, J; Hancock, S; Hill, C E; Jensen, E; Krusche, A; Lindroos, M; Métral, Elias; Métral, G; Metzmacher, K D; Olsfors, J; Pedersen, F; Raich, U; Riunaud, J P; Royer, J P; Sassowsky, M; Schindl, Karlheinz; Schönauer, Horst Otto; Thivent, M; Ullrich, H M; Völker, F V; Vretenar, Maurizio; Barnes, M; Blackmore, E W; Cifarelli, F; Clark, G; Jones, F; Koscielniak, Shane Rupert; Mammarella, F; Mitra, A; Poirier, R; Reiniger, K W; Ries, T C

    2000-01-01

    The LHC [1] will be supplied, via the SPS, with protons from the pre-injector chain comprising Linac2, PS Booster (PSB) and PS. These accelerators have under-gone a major upgrading programme [2] during the last five years so as to meet the stringent requirements of the LHC. These imply that many high-intensity bunches of small emittance and tight spacing (25 ns) be available at the PS extraction energy (25 GeV). The upgrading project involved an increase of Linac2 current, new RF systems in the PSB and the PS, raising the PSB energy from 1 to 1.4 GeV, two-batch filling of the PS and the installation of high-resolution beam profile measurement devices. With the project entering its final phase and most of the newly installed hardware now being operational, the emphasis switches to producing the nominal LHC beam and tackling the associated beam physics problems. While a beam with transverse characteristics better than nominal has been obtained, the longitudinal density still needs to be increased. An alternativ...

  13. Pressure Monitoring Using Hybrid fs/ps Rotational CARS

    Science.gov (United States)

    Kearney, Sean P.; Danehy, Paul M.

    2015-01-01

    We investigate the feasibility of gas-phase pressure measurements at kHz-rates using fs/ps rotational CARS. Femtosecond pump and Stokes pulses impulsively prepare a rotational Raman coherence, which is then probed by a high-energy 6-ps pulse introduced at a time delay from the Raman preparation. Rotational CARS spectra were recorded in N2 contained in a room-temperature gas cell for pressures from 0.1 to 3 atm and probe delays ranging from 10-330 ps. Using published self-broadened collisional linewidth data for N2, both the spectrally integrated coherence decay rate and the spectrally resolved decay were investigated as means for detecting pressure. Shot-averaged and single-laser-shot spectra were interrogated for pressure and the accuracy and precision as a function of probe delay and cell pressure are discussed. Single-shot measurement accuracies were within 0.1 to 6.5% when compared to a transducer values, while the precision was generally between 1% and 6% of measured pressure for probe delays of 200 ps or more, and better than 2% as the delay approached 300 ps. A byproduct of the pressure measurement is an independent but simultaneous measurement of the gas temperature.

  14. Defined lipid analogues induce transient channels to facilitate drug-membrane traversal and circumvent cancer therapy resistance

    NARCIS (Netherlands)

    van Hell, Albert J.; Melo, Manuel N.; van Blitterswijk, Wim J.; Gueth, Dayana M.; Braumuller, Tanya M.; Pedrosa, Lilia R. C.; Song, Ji-Ying; Marrink, Siewert J.; Koning, Gerben A.; Jonkers, Jos; Verheij, Marcel

    2013-01-01

    Design and efficacy of bioactive drugs is restricted by their (in) ability to traverse cellular membranes. Therapy resistance, a major cause of ineffective cancer treatment, is frequently due to suboptimal intracellular accumulation of the drug. We report a molecular mechanism that promotes

  15. Bloom syndrome complex promotes FANCM recruitment to stalled replication forks and facilitates both repair and traverse of DNA interstrand crosslinks.

    Science.gov (United States)

    Ling, Chen; Huang, Jing; Yan, Zhijiang; Li, Yongjiang; Ohzeki, Mioko; Ishiai, Masamichi; Xu, Dongyi; Takata, Minoru; Seidman, Michael; Wang, Weidong

    2016-01-01

    The recruitment of FANCM, a conserved DNA translocase and key component of several DNA repair protein complexes, to replication forks stalled by DNA interstrand crosslinks (ICLs) is a step upstream of the Fanconi anemia (FA) repair and replication traverse pathways of ICLs. However, detection of the FANCM recruitment has been technically challenging so that its mechanism remains exclusive. Here, we successfully observed recruitment of FANCM at stalled forks using a newly developed protocol. We report that the FANCM recruitment depends upon its intrinsic DNA translocase activity, and its DNA-binding partner FAAP24. Moreover, it is dependent on the replication checkpoint kinase, ATR; but is independent of the FA core and FANCD2-FANCI complexes, two essential components of the FA pathway, indicating that the FANCM recruitment occurs downstream of ATR but upstream of the FA pathway. Interestingly, the recruitment of FANCM requires its direct interaction with Bloom syndrome complex composed of BLM helicase, Topoisomerase 3α, RMI1 and RMI2; as well as the helicase activity of BLM. We further show that the FANCM-BLM complex interaction is critical for replication stress-induced FANCM hyperphosphorylation, for normal activation of the FA pathway in response to ICLs, and for efficient traverse of ICLs by the replication machinery. Epistasis studies demonstrate that FANCM and BLM work in the same pathway to promote replication traverse of ICLs. We conclude that FANCM and BLM complex work together at stalled forks to promote both FA repair and replication traverse pathways of ICLs.

  16. Perceiving and Traversing In-Class and Out-of-Class Learning: Accounts from Foreign Language Learners in Hong Kong

    Science.gov (United States)

    Lai, Chun

    2015-01-01

    Learning takes place across different social contexts, and understanding how learners perceive and traverse different learning contexts enables educators to gain a more comprehensive view of their learning processes and to support their learning better. This study examined how undergraduate foreign language learners perceived their learning…

  17. Final Results on the CERN PS Electrostatic Septa Consolidation Program

    CERN Document Server

    Borburgh, Jan; Bobbio, Piero; Carlier, Etienne; Hourican, Michael; Masson, Thierry; Müller, Tania; Prost, Antoine; Crescenti, Massimo

    2003-01-01

    The CERN PS electrostatic septum consolidation program is coming to completion after almost 4 years of development. The program was started to fulfil the increased requirements on vacuum performance and the need to reduce the time necessary for maintenance interventions. The new design of septum 31, used for the so-called 'continuous transfer' 5-turn extraction, and the related construction issues will be presented together with the operational experience gained during the PS 2002 run. In addition, the experience of two years of operation with the new generation septum 23, used for a resonant slow extraction, will be briefly discussed. The continued development undertaken since its installation in the PS ring in 2001 will also be described.

  18. A&T Sector Note on the PS transverse feedback

    CERN Document Server

    Coly, Marcel; Blas, Alfred; Sterbini, Guido; CERN. Geneva. ATS Department

    2017-01-01

    In a particle accelerator, several contributions can degrade the beam quality and particularly the beam transverse emittance. In this document we will describe a system used in the CERN Proton Synchrotron (PS) to cope with the injection steering errors and the transverse instabilities: the PS transverse feedback (PS TFB). As time progresses, this system is also being used for other purpose, to increase in a controlled way the beam transverse emittance and to excite the beam for the Multi-Turn-Extraction (MTE). In 2016, it has been successfully used on some operational beams to damp injection oscillations. This allowed to test the reliability of the system for its operational deployment. A piquet service is available in case of problem.

  19. SAFETY: STRICTER CONTROLS IN CONTROLLED AREAS IN THE PS

    CERN Document Server

    G. Daems

    2001-01-01

    The PS accelerators will soon stop for several months. Work will take place in controlled areas in the PS and will involve many people who are not always aware of the risks associated with the work sites. To guarentee the safety of these workers, the following two measures will be applied: everyone working in a controlled zone - Linacs, PSB, and PS machines tunnels, and transfer lines - must wear, visibly, his CERN access card and his film badge. the CERN access card and the film badge will only be issued after following a basic safety course. Regular checks will be carried out during the shutdown. Anyone without these two items on their person will be obliged to leave the area immediately.

  20. Electrophysical properties of PMN-PT-PS-PFN:Li ceramics

    Directory of Open Access Journals (Sweden)

    R. Skulski

    2013-01-01

    Full Text Available We present the technology of obtaining and the electrophysical properties of a multicomponent material 0.61PMN-0.20PT-0.09PS-0.1PFN:Li (PMN-PT-PS-PFN:Li. The addition of PFN into PMN-PT decreases the temperature of final sintering which is very important during technological process (addition of Li decreases electric conductivity of PFN. Addition of PS i.e., PbSnO3 (which is unstable in ceramic form permits to shift the temperature of the maximum of dielectric permittivity. One-step method of obtaining ceramic samples from oxides and carbonates has been used. XRD, microstructure, scanning calorimetry measurements and the main dielectric, ferroelectric and electromechanical properties have been investigated for the obtained samples.

  1. Effect of interfaces on the melting of PEO confined in triblock PS-b-PEO-b-PS copolymers.

    Science.gov (United States)

    Beaudoin, E; Phan, T N T; Robinet, M; Denoyel, R; Davidson, P; Bertin, D; Bouchet, R

    2013-08-27

    Block copolymers form nanostructures that have interesting physical properties because they combine, for a single compound, the complementary features brought by each block. However, in order to fully exploit these properties, the physical state of each kind of domain must be precisely controlled. In this work, triblock PS-b-PEO-b-PS copolymers consisting of a central poly(ethylene oxide) (PEO) block covalently bonded to polystyrene (PS) blocks were synthesized by Atom Transfer Radical Polymerization. Their morphology was investigated by X-ray scattering and TEM experiments whereas their thermodynamic behavior was characterized by DSC. A strong decrease of both the melting temperature and the degree of crystallinity of PEO, due to its confinement between the PS domains, was observed and analyzed with a modified Gibbs-Thomson equation, following the approaches used for fluids confined in porous media. The existence of an amorphous bound layer, a few nanometers thick, at the PEO/PS interface, that does not undergo any phase transition in the temperature range investigated, accounts for both the melting temperature depression and the decrease of crystallinity upon confinement. This interfacial layer may significantly affect the mechanical and transport properties of these block copolymers that find applications as solid polymer electrolytes in batteries for example. Moreover, the value obtained for the solid PEO/liquid PEO surface tension is lower than those previously published but is thermodynamically consistent with the surface tensions of polymers at the solid/vapor and liquid/vapor interfaces.

  2. First Gravity Traverse on the Martian Surface from the Curiosity Rover

    Science.gov (United States)

    Lewis, K. W.; Peters, S. F.; Gonter, K. A.; Vasavada, A. R.

    2016-12-01

    Orbital gravity surveys have been a key tool in understanding planetary interiors and shallow crustal structure, exemplified by recent missions such as GRAIL and Juno. However, due to the loss of spatial resolution with altitude, airborne and ground-based survey methods are typically employed on the Earth. Previously, the Lunar Traverse Gravimeter experiment on the Apollo 17 mission has been the only attempt to collect surface gravity measurements on another planetary body. We will describe the results of the first gravity survey on the Martian surface, using data from the Curiosity rover over its >10 km traverse across the floor of Gale crater and lower slopes of Mount Sharp. These results enable us to estimate bulk rock density, and to search for potential subsurface density anomalies. To measure local gravitational acceleration, we use one of the two onboard Rover Inertial Measurement Units (RIMU-A), designed for rover position and fine attitude determination. The IMU contains three-axis micro-electromechanical (MEMS) accelerometers and fiber-optic gyros, and is used for gyrocompassing by integrating data for several minutes on sols with no drive or arm motions (roughly 50% of sols to date). Raw acceleration data are calibrated for biases induced by temperature effects and rover orientation, along with rover elevation over the course of the mission using multiple regression. We use the best fit linear relationship between topographic height and gravitational acceleration to estimate a Bouguer correction for the observed change in magnitude over the mission as the rover has ascended over 100 meters up the lower slopes of Mount Sharp. We find a relatively low best-fit density of 1600 +/- 500 kg/m^3 for the rocks of Mount Sharp, consistent with rover-based measurements of thermal inertial, and potentially indicating pervasive fracturing, high porosity and/or low compaction within the original sediments at least to depths of order 100 meters. Future measurements

  3. Inauguration of POPS: the new power system of the PS

    CERN Multimedia

    Maximilien Brice

    2010-01-01

    Pictures 03 and 04 : The team from the Electrical Power Converters Group (TE/EPC) is joined by the Director of Accelerators, the heads of the BE, TE and FI departments, CERN managers and Converteam representatives in a group portrait in front of three of the containers that house the capacitor banks of the PS's new power supply system, POPS. Pictures 01, 06 and 07 : Magid-Michel Saikaly, energy and infrastructure director at Converteam, receives a prize from Steve Myers, Director of Accelerators at CERN, for the development and fabrication of the new electrical power system for the PS, called POPS.

  4. The Septa for LEIR Extraction and PS Injection

    CERN Document Server

    Borburgh, J; Masson, T; Prost, A

    2006-01-01

    The Low Energy Ion Ring (LEIR) is part of the CERN LHC injector chain for ions. The LEIR extraction uses a pulsed magnetic septum, clamped around a metallic vacuum chamber. Apart from separating the ultra high vacuum in the LEIR ring from the less good vacuum in the transfer line to the PS this chamber also serves as magnetic screen and retains the septum conductor in place. The PS ion injection septum consists of a pulsed laminated magnet under vacuum, featuring a single-turn water cooled coil and a remote positioning system. The design, the construction and the commissioning of both septa are described.

  5. The OMERACT psoriatic arthritis magnetic resonance imaging scoring system (PsAMRIS): definitions of key pathologies, suggested MRI sequences, and preliminary scoring system for PsA Hands

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; McQueen, Fiona; Wiell, Charlotte

    2009-01-01

    This article describes a preliminary OMERACT psoriatic arthritis magnetic resonance image scoring system (PsAMRIS) for evaluation of inflammatory and destructive changes in PsA hands, which was developed by the international OMERACT MRI in inflammatory arthritis group. MRI definitions of important...... pathologies in peripheral PsA and suggestions concerning appropriate MRI sequences for use in PsA hands are also provided....

  6. Dissociations between the effects of LSD on behavior and raphe unit activity in freely moving cats.

    Science.gov (United States)

    Trulson, M E; Jacobs, B L

    1979-08-03

    The hypothesis that the action of hallucinogenic drugs is mediated by a depression of the activity of brain serotonergic (raphe) neurons was tested by examining the behavioral effects of d-lysergic acid diethylamide (LSD) while studying the activity of raphe neurons in freely moving cats. Although the results provide general support for the hypothesis, there were several important dissociations. (i) Low doses of LSD produced only small decreases in raphe unit activity but significant behavoiral changes; (ii) LSD-induced behavioral changes outlasted the depression of raphe unit activity; and (iii) raphe neurons were at least as responsive to LSD during tolerance as they were in the nontolerant condition.

  7. Estimation of unsteady aerodynamics in the wake of a freely flying European starling

    OpenAIRE

    Hadar Ben-Gida; Adam Kirchhefer; Taylor, Zachary J.; Wayne Bezner-Kerr; Guglielmo, Christopher G.; Kopp, Gregory A.; Roi Gurka

    2013-01-01

    Wing flapping is one of the most widespread propulsion methods found in nature; however, the current understanding of the aerodynamics in bird wakes is incomplete. The role of the unsteady motion in the flow and its contribution to the aerodynamics is still an open question. In the current study, the wake of a freely flying European starling has been investigated using long-duration high-speed Particle Image Velocimetry (PIV) in the near wake. Kinematic analysis of the wings and body of the b...

  8. Deformation and burst of a liquid droplet freely suspended in a linear shear field

    Science.gov (United States)

    Barthes-Biesel, D.; Acrivos, A.

    1973-01-01

    A theoretical method is presented for predicting the deformation and the conditions for breakup of a liquid droplet freely suspended in a general linear shear field. This is achieved by expanding the solution to the creeping-flow equations in powers of the deformation parameter epsilon and using linear stability theory to determine the onset of bursting. When compared with numerical solutions and with the available experimental data, the theoretical results are generally found to be of acceptable accuracy although, in some cases, the agreement is only qualitative.

  9. Biopython: freely available Python tools for computational molecular biology and bioinformatics.

    Science.gov (United States)

    Cock, Peter J A; Antao, Tiago; Chang, Jeffrey T; Chapman, Brad A; Cox, Cymon J; Dalke, Andrew; Friedberg, Iddo; Hamelryck, Thomas; Kauff, Frank; Wilczynski, Bartek; de Hoon, Michiel J L

    2009-06-01

    The Biopython project is a mature open source international collaboration of volunteer developers, providing Python libraries for a wide range of bioinformatics problems. Biopython includes modules for reading and writing different sequence file formats and multiple sequence alignments, dealing with 3D macro molecular structures, interacting with common tools such as BLAST, ClustalW and EMBOSS, accessing key online databases, as well as providing numerical methods for statistical learning. Biopython is freely available, with documentation and source code at (www.biopython.org) under the Biopython license.

  10. $\\Phi$-moment inequalities for independent and freely independent random variables

    OpenAIRE

    Jiao, Yong; Sukochev, Fedor; Xie, Guangheng; Zanin, Dmitriy

    2016-01-01

    This paper is devoted to the study of $\\Phi$-moments of sums of independent/freely independent random variables. More precisely, let $(f_k)_{k=1}^n$ be a sequence of positive (symmetrically distributed) independent random variables and let $\\Phi$ be an Orlicz function with $\\Delta_2$-condition. We provide an equivalent expression for the quantity $\\mathbb{E}(\\Phi(\\sum_{k=1}^n f_k))$ in term of the sum of disjoint copies of the sequence $(f_k)_{k=1}^n.$ We also prove an analogous result in the...

  11. Fabrication of Freely Patterned Aligned Nematic Liquid Crystal Cells Using UV Laser Scanning Photoalignment

    Science.gov (United States)

    Hasegawa, Masaki

    2002-02-01

    We have fabricated freely patterned aligned liquid crystal (LC) cells using photoalignment. Our apparatus has a sample stage and a UV Ar+ laser with a nonlinear optical crystal, and can provide arbitrary orientations of polarized UV light at any point on a substrate. In this paper we describe the fabrication method for the cells and the various patterns of aligned LC cells that can be produced within the resolution limitations of our apparatus. This study shows possible applications of photoalignment for the fabrication of photonic devices.

  12. Vibration suppression of curved beams traversed by off-center moving loads

    Science.gov (United States)

    Rostam, M. R.; Javid, F.; Esmailzadeh, E.; Younesian, D.

    2015-09-01

    In this study six different vibration control strategies are proposed to suppress both the flexural and torsional vibrations of a curved beam traversed by off-center moving loads. The various vibration control strategies employed are: (i) separate tuned-mass-dampers (TMDs), (ii) linked TMDs with a massless connecting rod, (iii) distributed TMDs system, (iv) linked TMDs with intermediate connection, (v) separate TMDs with intermediate dissipating system, and finally (vi) the nonlinear energy sinks (NESs). The curved beam is modeled using finite element model. An optimal design of TMD system is proposed to suppress the effect of non-symmetrical and side-way motion of vehicles traveling on bridges. The dynamic performance of the proposed vibration control strategies are thoroughly evaluated while subjected to different loading conditions: (a) successive moving loads and (b) broadband random excitation. It is shown that while all the proposed strategies can remarkably suppress both types of the vibration, the fifth strategy is the most effective one that provides the largest value of the bending and torsional vibration reduction in the first loading condition.

  13. Thermophysical properties along Curiosity's traverse in Gale crater, Mars, derived from the REMS ground temperature sensor

    Science.gov (United States)

    Vasavada, Ashwin R.; Piqueux, Sylvain; Lewis, Kevin W.; Lemmon, Mark T.; Smith, Michael D.

    2017-03-01

    The REMS instrument onboard the Mars Science Laboratory rover, Curiosity, has measured ground temperature nearly continuously at hourly intervals for two Mars years. Coverage of the entire diurnal cycle at 1 Hz is available every few martian days. We compare these measurements with predictions of surface-atmosphere thermal models to derive the apparent thermal inertia and thermally derived albedo along the rover's traverse after accounting for the radiative effects of atmospheric water ice during fall and winter, as is necessary to match the measured seasonal trend. The REMS measurements can distinguish between active sand, other loose materials, mudstone, and sandstone based on their thermophysical properties. However, the apparent thermal inertias of bedrock-dominated surfaces (∼350-550 J m-2 K-1 s-½) are lower than expected. We use rover imagery and the detailed shape of the diurnal ground temperature curve to explore whether lateral or vertical heterogeneity in the surface materials within the sensor footprint might explain the low inertias. We find that the bedrock component of the surface can have a thermal inertia as high as 650-1700 J m-2 K-1 s-½ for mudstone sites and ∼700 J m-2 K-1 s-½ for sandstone sites in models runs that include lateral and vertical mixing. Although the results of our forward modeling approach may be non-unique, they demonstrate the potential to extract information about lateral and vertical variations in thermophysical properties from temporally resolved measurements of ground temperature.

  14. An FMM based on dual tree traversal for many-core architectures

    KAUST Repository

    Yokota, Rio

    2013-09-01

    The present work attempts to integrate the independent efforts in the fast N-body community to create the fastest N-body library for many-core and heterogenous architectures. Focus is placed on low accuracy optimizations, in response to the recent interest to use FMM as a preconditioner for sparse linear solvers. A direct comparison with other state-of-the-art fast N-body codes demonstrates that orders of magnitude increase in performance can be achieved by careful selection of the optimal algorithm and low-level optimization of the code. The current N-body solver uses a fast multipole method with an efficient strategy for finding the list of cell-cell interactions by a dual tree traversal. A task-based threading model is used to maximize thread-level parallelism and intra-node load-balancing. In order to extract the full potential of the SIMD units on the latest CPUs, the inner kernels are optimized using AVX instructions.

  15. Optimization of protease production by an actinomycete Strain, PS ...

    African Journals Online (AJOL)

    Actinomycetes were isolated from the sediment samples of an estuarine shrimp pond located along the south east coast of India. During the investigation, a total of 28 strains of actinomycetes were isolated and examined for their protease activity. Among them, one strain PS-18A which was tentatively identified as ...

  16. Seismic receiver function interpretation: Ps splitting or anisotropic underplating?

    Science.gov (United States)

    Liu, Zhen; Park, Jeffrey

    2017-03-01

    Crustal anisotropy is crucial to understanding the evolutionary history of Earth's lithosphere. Shear wave splitting of Moho P-to-S converted phases in receiver functions (RFs) have been often used to study crustal anisotropy. Harmonic variation of Moho Ps phases in delay times are used to infer splitting parameters of averaged anisotropy in the crust. However, crustal anisotropy may distribute at various levels within the crust due to complex deformational processes. Layered anisotropy requires careful investigation of the distribution of anisotropy before interpreting Moho Ps splitting. In this study, we show results from stations ARU in Russia, KIP in the Hawaiian Islands and LSA in Tibetan Plateau, where layered anisotropy is constrained well by intracrust Ps conversions at high frequencies using a harmonic-decomposition technique. Anisotropic velocity models are inferred by forward-modeling decomposed RF waveforms. We suggest that the harmonic variation of Moho Ps phases should always be investigated to check for anisotropic layering using RFs with frequency content above 1 Hz, rather than simply reporting averaged anisotropy of the whole crust.

  17. Optimization of protease production by an actinomycete Strain, PS ...

    African Journals Online (AJOL)

    STORAGESEVER

    Isolation Agar Medium in duplicate Petri plates. To minimize ... on the Petri plates were counted from 5th day onwards, up to 28th .... After the dialysis, the volume was measured and analyzed for proteins and stored in deep freezer. Taxonomic investigation. The genus level identification was made for the strain PS-18A using ...

  18. Framing Retention for Institutional Improvement: A 4 Ps Framework

    Science.gov (United States)

    Kalsbeek, David H.

    2013-01-01

    A 4 Ps framework for student retention strategy is a construct for reframing the retention discussion in a way that enables institutional improvement by challenging some conventional wisdom and prevailing perspectives that have characterized retention strategy for years. It opens new possibilities for action and improvement by suggesting that…

  19. Multipole stack for the 4 rings of the PS Booster

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    The PS Booster (originally 800 MeV, now 1.4 GeV) saw first beam in 1972, routine operation began in 1973. The strive for ever higher intensities required the addition of multipoles. Manufacture of 8 stacks of multipoles was launched in 1974, for installation in 1976. For details, see 7511120X.

  20. The Swelling Behaviour of Polystyrene (PS)/ Polyvinylacetate (Pvac ...

    African Journals Online (AJOL)

    The effect of the variation of the type of solvent responsible for the differences in the swelling kinetics of Polystyrene (PS) and Polyvinyl acetate (PVAc) blends was studied. The results showed that the nature of solvent control or affects the degree of swelling. Also, 1-V characteristics at temperature range of 323-363K shows ...

  1. Boiling treatment of ABS and PS plastics for flotation separation.

    Science.gov (United States)

    Wang, Chong-qing; Wang, Hui; Wu, Bao-xin; Liu, Qun

    2014-07-01

    A new physical method, namely boiling treatment, was developed to aid flotation separation of acrylonitrile-butadiene-styrene (ABS) and polystyrene (PS) plastics. Boiling treatment was shown to be effective in producing a hydrophilic surface on ABS plastic. Fourier Transform Infrared analysis was conducted to investigate the mechanism of boiling treatment of ABS. Surface rearrangement of polymer may be responsible for surface change of boiling treated ABS, and the selective influence of boiling treatment on the floatability of boiling treated plastics may be attributed to the difference in the molecular mobility of polymer chains. The effects of flotation time, frother concentration and particle size on flotation behavior of simple plastic were investigated. Based on flotation behavior of simple plastic, flotation separation of boiling treatment ABS and PS with different particle sizes was achieved efficiently. The purity of ABS and PS was up to 99.78% and 95.80%, respectively; the recovery of ABS and PS was up to 95.81% and 99.82%, respectively. Boiling treatment promotes the industrial application of plastics flotation and facilitates plastic recycling. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Calculating Puerto Rico’s Ecological Footprint (1970–2010 Using Freely Available Data

    Directory of Open Access Journals (Sweden)

    Matthew E. Hopton

    2015-07-01

    Full Text Available Ecological Footprint Analysis (EFA is appealing as a metric of sustainability because it is straightforward in theory and easy to conceptualize. However, EFA is difficult to implement because it requires extensive data. A simplified approach to EFA that requires fewer data can serve as a perfunctory analysis allowing researchers to examine a system with relatively little cost and effort. We examined whether a simplified approach using freely available data could be applied to Puerto Rico, a densely populated island with limited land resources. Forty-one years of data were assembled to compute the ecological footprint from 1970 to 2010. According to EFA, individuals in Puerto Rico were moving toward sustainability over time, as the per capita ecological footprint decreased from 3.69 ha per capita (ha/ca in 1970 to 3.05 ha/ca in 2010. However, due to population growth, the population’s footprint rose from 1.00 × 107 ha in 1970 to 1.14 × 107 ha in 2010, indicating Puerto Rico as a whole was moving away from sustainability. Our findings demonstrate the promise for conducting EFA using a simplified approach with freely available data, and we discuss potential limitations on data quality and availability that should be addressed to further improve the science.

  3. Parallel pain processing in freely moving rats revealed by distributed neuron recording.

    Science.gov (United States)

    Wang, Jin-Yan; Luo, Fei; Chang, Jing-Yu; Woodward, Donald J; Han, Ji-Sheng

    2003-12-05

    The present study was designed to examine the possible differential roles of the medial and lateral pain systems in pain perception. We used a microwire array recording technique to record the pain-evoked neural activity of multiple neurons in freely moving rats. Noxious radiant heat was delivered to either hind-paw in a randomized order. A total of 256 single units were recorded in primary somatosensory cortex (SI), anterior cingulate cortex (ACC), and medial dorsal (MD) and ventral posterior (VP) thalamus during the painful stimulation. The results showed that SI neurons displayed a strong pain-related excitatory response with short duration and significant contralateral bias; VP had very similar functional patterns to that of SI. This suggested that SI, together with VP, participate in the processing of the sensory-discriminative aspect of pain. In contrast, ACC and MD shared common characteristics of moderate and longer-lasting increase of neural activity, bilateral receptive fields without contralateral preference, as well as the anticipatory response at the start of a painful stimulus, corresponding to the specific role of ACC and MD in the affective-motivational aspects of pain. The results provide an initial demonstration of distributed activity patterns within different pain systems in awake and freely moving rats, hence, providing confirmation of the existence of the dual pain pathways.

  4. Single-molecule-sensitive fluorescence resonance energy transfer in freely-diffusing attoliter droplets

    Energy Technology Data Exchange (ETDEWEB)

    Rahmanseresht, Sheema; Ramos, Kieran P.; Gamari, Ben D.; Goldner, Lori S., E-mail: lgoldner@physics.umass.edu [Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Milas, Peker [Department of Neuroscience, University of Wisconsin, Madison, Wisconsin 53705 (United States)

    2015-05-11

    Fluorescence resonance energy transfer (FRET) from individual, dye-labeled RNA molecules confined in freely-diffusing attoliter-volume aqueous droplets is carefully compared to FRET from unconfined RNA in solution. The use of freely-diffusing droplets is a remarkably simple and high-throughput technique that facilitates a substantial increase in signal-to-noise for single-molecular-pair FRET measurements. We show that there can be dramatic differences between FRET in solution and in droplets, which we attribute primarily to an altered pH in the confining environment. We also demonstrate that a sufficient concentration of a non-ionic surfactant mitigates this effect and restores FRET to its neutral-pH solution value. At low surfactant levels, even accounting for pH, we observe differences between the distribution of FRET values in solution and in droplets which remain unexplained. Our results will facilitate the use of nanoemulsion droplets as attoliter volume reactors for use in biophysical and biochemical assays, and also in applications such as protein crystallization or nanoparticle synthesis, where careful attention to the pH of the confined phase is required.

  5. Differential Responses of Thalamic Reticular Neurons to Nociception in Freely Behaving Mice

    Science.gov (United States)

    Huh, Yeowool; Cho, Jeiwon

    2016-01-01

    Pain serves an important protective role. However, it can also have debilitating adverse effects if dysfunctional, such as in pathological pain conditions. As part of the thalamocortical circuit, the thalamic reticular nucleus (TRN) has been implicated to have important roles in controlling nociceptive signal transmission. However studies on how TRN neurons, especially how TRN neuronal subtypes categorized by temporal bursting firing patterns—typical bursting, atypical bursting and non-bursting TRN neurons—contribute to nociceptive signal modulation is not known. To reveal the relationship between TRN neuronal subtypes and modulation of nociception, we simultaneously recorded behavioral responses and TRN neuronal activity to formalin induced nociception in freely moving mice. We found that typical bursting TRN neurons had the most robust response to nociception; changes in tonic firing rate of typical TRN neurons exactly matched changes in behavioral nociceptive responses, and burst firing rate of these neurons increased significantly when behavioral nociceptive responses were reduced. This implies that typical TRN neurons could critically modulate ascending nociceptive signals. The role of other TRN neuronal subtypes was less clear; atypical bursting TRN neurons decreased tonic firing rate after the second peak of behavioral nociception and the firing rate of non-bursting TRN neurons mostly remained at baseline level. Overall, our results suggest that different TRN neuronal subtypes contribute differentially to processing formalin induced sustained nociception in freely moving mice. PMID:27917114

  6. Continuous Force Decoding from Local Field Potentials of the Primary Motor Cortex in Freely Moving Rats.

    Science.gov (United States)

    Khorasani, Abed; Heydari Beni, Nargess; Shalchyan, Vahid; Daliri, Mohammad Reza

    2016-10-21

    Local field potential (LFP) signals recorded by intracortical microelectrodes implanted in primary motor cortex can be used as a high informative input for decoding of motor functions. Recent studies show that different kinematic parameters such as position and velocity can be inferred from multiple LFP signals as precisely as spiking activities, however, continuous decoding of the force magnitude from the LFP signals in freely moving animals has remained an open problem. Here, we trained three rats to press a force sensor for getting a drop of water as a reward. A 16-channel micro-wire array was implanted in the primary motor cortex of each trained rat, and obtained LFP signals were used for decoding of the continuous values recorded by the force sensor. Average coefficient of correlation and the coefficient of determination between decoded and actual force signals were r = 0.66 and R(2) = 0.42, respectively. We found that LFP signal on gamma frequency bands (30-120 Hz) had the most contribution in the trained decoding model. This study suggests the feasibility of using low number of LFP channels for the continuous force decoding in freely moving animals resembling BMI systems in real life applications.

  7. An Ambulatory Electroencephalography System for Freely Moving Horses: An Innovating Approach

    Science.gov (United States)

    Cousillas, Hugo; Oger, Martial; Rochais, Céline; Pettoello, Claire; Ménoret, Mathilde; Henry, Séverine; Hausberger, Martine

    2017-01-01

    Electroencephalography (EEG) that has been extensively studied in humans presents also a large interest for studies on animal brain processes. However, since the quality of the recordings is altered by muscular activity, most EEG recordings on animals are obtained using invasive methods with deeply implanted electrodes. This requires anesthesia and can thus only be used in laboratory or clinical settings. As EEG is a very useful tool both for detecting brain alterations due to diseases or accidents and to evaluate the arousal and attentional state of the animal, it seemed crucial to develop a tool that would make such recordings possible in the horse’s home environment, with a freely moving horse. Such a tool should neither be invasive nor cause discomforts to the horse as the usual other practice which consists, after shaving the zone, in gluing the electrodes to the skin. To fulfill these requirements, we developed a novel EEG headset adapted to the horse’s head that allows an easy and fast positioning of the electrodes and that can be used in the home environment on a freely moving horse. In this study, we show that this EEG headset allows to obtain reliable recordings, and we propose an original evaluation of an animal’s “EEG profile” that allows comparisons between individuals and situations. This EEG headset opens new possibilities of investigation on horse cognition, and it can also become a useful tool for veterinarians to evaluate cerebral disorders or check the anesthesia level during a surgery. PMID:28512633

  8. The role of a conserved membrane proximal cysteine in altering αPS2CβPS integrin diffusion

    Science.gov (United States)

    Syed, Aleem; Arora, Neha; Bunch, Thomas A.; Smith, Emily A.

    2016-12-01

    Cysteine residues (Cys) in the membrane proximal region are common post-translational modification (PTM) sites in transmembrane proteins. Herein, the effects of a highly conserved membrane proximal α-subunit Cys1368 on the diffusion properties of αPS2CβPS integrins are reported. Sequence alignment shows that this cysteine is palmitoylated in human α3 and α6 integrin subunits. Replacing Cys1368 in wild-type integrins with valine (Val1368) putatively blocks a PTM site and alters integrins’ ligand binding and diffusion characteristics. Both fluorescence recovery after photobleaching (FRAP) and single particle tracking (SPT) diffusion measurements show Val1368 integrins are more mobile compared to wild-type integrins. Approximately 33% and 8% more Val1368 integrins are mobile as measured by FRAP and SPT, respectively. The mobile Val1368 integrins also exhibit less time-dependent diffusion, as measured by FRAP. Tandem mass spectrometry data suggest that Cys1368 contains a redox or palmitoylation PTM in αPS2CβPS integrins. This membrane proximal Cys may play an important role in the diffusion of other alpha subunits that contain this conserved residue.

  9. Variations in snow and firn chemistry along US ITASE traverses and the effect of surface glazing

    Directory of Open Access Journals (Sweden)

    D. A. Dixon

    2013-03-01

    Full Text Available This study provides a baseline from which changes in the chemistry of the atmosphere over Antarctica can be monitored under expected warming scenarios and continued intensification of industrial activities in the Southern Hemisphere. It is the first study to measure more than 25 chemical constituents in the surface snow and firn across extensive regions of Antarctica. We present major ion, trace element, heavy metal, rare earth element and oxygen isotope data from a series of surface snow samples and shallow firn sections collected along four US ITASE traverses across East and West Antarctica. In each sample we measure dissolved concentrations of Na+, K+, Mg2+, Ca2+, Cl−, NO3+, SO42−, and MS− using ion chromatography and total concentrations of Sr, Cd, Cs, Ba, La, Ce, Pr, Pb, Bi, U, As, Al, S, Ca, Ti, V, Cr, Mn, Fe, Co, Na, Mg, Li, and K using inductively coupled plasma sector field mass spectrometry (ICP-SFMS. We also measure δ18O by isotope ratio mass spectrometry. Satellite remote sensing measurements of microwave backscatter and grain size are used to assist in the identification of glaze/dune areas across Antarctica and determine if these areas can possibly contain useful chemical climate records. The majority of the non-glaze/dune samples in this study exhibit similar, or lower, concentrations to those from previous studies. Consequently, the results presented here comprise a conservative baseline for Antarctic surface snow chemical concentrations. The elements Cd, Pb, As and Bi are enriched across Antarctica relative to both ocean and upper crust elemental ratios. Local and global volcanic outgassing may account for the majority of the Bi measured in East and West Antarctica and for a significant fraction of the Cd and As. However, significant concentrations of Cd, Pb, and As remain across much of Antarctica.

  10. Thermophysical Properties Along Curiosity's Traverse in Gale Crater, Mars, Derived from the REMS Ground Temperature Sensor

    Science.gov (United States)

    Vasavada, Ashwin R.; Piqueux, Sylvain; Lewis, Kevin W.; Lemmon, Mark T.; Smith, Michael Doyle

    2016-01-01

    The REMS instrument onboard the Mars Science Laboratory rover, Curiosity, has measured ground temperature nearly continuously at hourly intervals for two Mars years. Coverage of the entire diurnal cycle at 1 Hz is available every few martian days. We compare these measurements with predictions of surface atmosphere thermal models to derive the apparent thermal inertia and thermally derived albedo along the rovers traverse after accounting for the radiative effects of atmospheric water ice during fall and winter, as is necessary to match the measured seasonal trend. The REMS measurements can distinguish between active sand, other loose materials, mudstone, and sandstone based on their thermophysical properties. However, the apparent thermal inertias of bedrock dominated surfaces [approx. 350-550 J m(exp. -2) K(exp. -1 s(exp. -1/2 )] are lower than expected. We use rover imagery and the detailed shape of the diurnal ground temperature curve to explore whether lateral or vertical heterogeneity in the surface materials within the sensor footprint might explain the low inertias. We find that the bedrock component of the surface can have a thermal inertia as high as 650-1700 J m(exp. -2) K(exp. -1) s(exp. -1/2) for mudstone sites and approx. 700 J m(exp. -2) K(exp. -1) s(exp. - 1/2) for sandstone sites in models runs that include lateral and vertical mixing. Although the results of our forward modeling approach may be non-unique, they demonstrate the potential to extract information about lateral and vertical variations in thermophysical properties from temporally resolved measurements of ground temperature.

  11. A free calcium wave traverses the activating egg of the medaka, Oryzias latipes

    Energy Technology Data Exchange (ETDEWEB)

    Gilkey, J.C.; Jaffee, L.E.; Ridgway, E.B.; Reynolds, G.T.

    1978-02-01

    Aequorin injected eggs of the medaka (a fresh water fish) show an explosive rise in free calcium during fertilization, which is followed by a slow return to the resting level. Image intensification techniques now show a spreading wave of high free calcium during fertilization. The wave starts at the animal pole (where the sperm enters) and then traverses the egg as a shallow, roughly 20/sup 0/-wide band which vanishes at the antipode some minutes later. The peak free calcium concentration within this moving band is estimated to be about 30 ..mu..M (perhaps 100 to 1,000 times the resting level). Eggs activated by ionophore A23187 may show multiple initiation sites. The resulting multiple waves never spread throuh each other, rather, they fuse upon meeting so as to form spreading waves of compound origin. The fertilization wave is nearly independent of extracellular calcium because it is only slightly slowed (by perhaps 15%) in a medium containing 5mM ethylene glycol-bis(..beta..-aminoethyl ether)N,N'-tetraacetic acid (EGTA) and no deliberately added calcium. It is also independent of the large cortical vesicles, which may be centrifugally displaced. Normally, however, it distinctly precedes the well-known wave of cortical vesicle exocytosis. We conclude that the fertilization wave in the medaka egg is propagated by calcium-stimulated calcium release, primarily from some internal sources other than the large cortical vesicles. A comparison of the characteristics of the exocytotic wave in the medaka with that in other eggs, particularly in echinoderm eggs, suggests that such a propagated calcium wave is a general feature of egg activation.

  12. Comparing Geologic Data Sets Collected by Planetary Analog Traverses and by Standard Geologic Field Mapping: Desert Rats Data Analysis

    Science.gov (United States)

    Feng, Wanda; Evans, Cynthia; Gruener, John; Eppler, Dean

    2014-01-01

    Geologic mapping involves interpreting relationships between identifiable units and landforms to understand the formative history of a region. Traditional field techniques are used to accomplish this on Earth. Mapping proves more challenging for other planets, which are studied primarily by orbital remote sensing and, less frequently, by robotic and human surface exploration. Systematic comparative assessments of geologic maps created by traditional mapping versus photogeology together with data from planned traverses are limited. The objective of this project is to produce a geologic map from data collected on the Desert Research and Technology Studies (RATS) 2010 analog mission using Apollo-style traverses in conjunction with remote sensing data. This map is compared with a geologic map produced using standard field techniques.

  13. Detecting Traversable Area and Water Hazards for the Visually Impaired with a pRGB-D Sensor

    Science.gov (United States)

    Yang, Kailun; Wang, Kaiwei; Cheng, Ruiqi; Hu, Weijian; Huang, Xiao; Bai, Jian

    2017-01-01

    The use of RGB-Depth (RGB-D) sensors for assisting visually impaired people (VIP) has been widely reported as they offer portability, function-diversity and cost-effectiveness. However, polarization cues to assist traversability awareness without precautions against stepping into water areas are weak. In this paper, a polarized RGB-Depth (pRGB-D) framework is proposed to detect traversable area and water hazards simultaneously with polarization-color-depth-attitude information to enhance safety during navigation. The approach has been tested on a pRGB-D dataset, which is built for tuning parameters and evaluating the performance. Moreover, the approach has been integrated into a wearable prototype which generates a stereo sound feedback to guide visually impaired people (VIP) follow the prioritized direction to avoid obstacles and water hazards. Furthermore, a preliminary study with ten blindfolded participants suggests its effectivity and reliability. PMID:28817069

  14. An Arduino microcontroller based digitalization of a vertical traversing mechanism used for the analysis of jet flows

    Science.gov (United States)

    Rahman, S. M. Rakibur; Roshid, S. M. Al Mamun Or; Nishan, Ishtiaque Ahmed

    2017-12-01

    This paper deals with the design of a drive system of traversing mechanism used to position the pitot tube in desired position of the jet flow field. In this system a stepper motor is driven by a `dual H bridge' motor driver and programmed Arduino microcontroller. The stepper motor is made to move in precise steps to obtain desired movement of the traversing mechanism. The jet flow is characterized in three distinct zones - initial zone, transition zone and developed zone. Each zone can be divided into required number of segments based on variation of velocity. By assigning number of segments, step range and number of steps in each segment as inputs, it is possible to collect data in all the flow zones according to our programmed schedule. The system will allow taking a large number of readings automatically.

  15. The mechanism of nucleosome traversal by RNA polymerase II: roles for template uncoiling and transcript elongation factors.

    Science.gov (United States)

    Luse, Donal S; Studitsky, Vasily M

    2011-01-01

    RNA polymerase II traverses nucleosomes rapidly and efficiently in the cell but it has not been possible to duplicate this process in the test tube. A single nucleosome has generally been found to provide a strong barrier to transcript elongation in vitro. Recent studies have shown that effective transcript elongation can occur on nucleosomal templates in vitro, but this depends on both facilitated uncoiling of DNA from the octamer surface and the presence of transcription factors that maintain polymerase in the transcriptionally competent state. These findings indicate that the efficiency and rate of transcription through chromatin could be regulated through controlled DNA uncoiling. These studies also demonstrate that nucleosome traversal need not result in nucleosome displacement.

  16. [Retinal Cell Therapy Using iPS Cells].

    Science.gov (United States)

    Takahashi, Masayo

    2016-03-01

    Progress in basic research, starting with the work on neural stem cells in the middle 1990's to embryonic stem (ES) cells and induced pluripotent stem (iPS) cells at present, will lead the cell therapy (regenerative medicine) of various organs, including the central nervous system to a big medical field in the future. The author's group transplanted iPS cell-derived retinal pigment epithelial (RPE) cell sheets to the eye of a patient with exudative age-related macular degeneration (AMD) in 2014 as a clinical research. Replacement of the RPE with the patient's own iPS cell-derived young healthy cell sheet will be one new radical treatment of AMD that is caused by cellular senescence of RPE cells. Since it was the first clinical study using iPS cell-derived cells, the primary endpoint was safety judged by the outcome one year after surgery. The safety of the cell sheet has been confirmed by repeated tumorigenisity tests using immunodeficient mice, as well as purity of the cells, karyotype and genetic analysis. It is, however, also necessary to prove the safety by clinical studies. Following this start, a good strategy considering cost and benefit is needed to make regenerative medicine a standard treatment in the future. Scientifically, the best choice is the autologous RPE cell sheet, but autologous cell are expensive and sheet transplantation involves a risky part of surgical procedure. We should consider human leukocyte antigen (HLA) matched allogeneic transplantation using the HLA 6 loci homozyous iPS cell stock that Prof. Yamanaka of Kyoto University is working on. As the required forms of donor cells will be different depending on types and stages of the target diseases, regenerative medicine will be accomplished in a totally different manner from the present small molecule drugs. Proof of concept (POC) of photoreceptor transplantation in mouse is close to being accomplished using iPS cell-derived photoreceptor cells. The shortest possible course for treatment

  17. A transmissão psíquica geracional

    Directory of Open Access Journals (Sweden)

    Vinícius Oliveira dos Santos

    Full Text Available O artigo seguinte refere-se a um estudo sobre como ocorre a transmissão psíquica entre as gerações e qual sua importância na constituição psíquica do sujeito. É também objetivo deste artigo explicar o que são as transmissões intergeracional e transgeracional. Para buscar respostas para essas questões, fez-se uma pesquisa bibliográfica sobre a transmissão psíquica, pelo viés psicanalítico, principalmente a partir da teoria lacaniana e com conceitos oriundos da linguística saussuriana. Será a partir de uma determinada ordem simbólica, constituída pela linguagem que precede o sujeito, nomeado por Lacan como o Outro, que a transmissão psíquica entre gerações ganhará o seu caráter unívoco, sempre se tendo em mente a importância fundamental do recalcamento e de seus efeitos, bem como do retorno do recalcado nas diferentes gerações. A transmissão psíquica é necessária e concomitante à constituição do sujeito, e ocorre através da linguagem, dos significantes que irão determinar uma ordem simbólica para o ser que nasce através dos diferentes discursos que perpassam as gerações nas figuras dos pais desse novo ser. Essa ordem simbólica continuará a se fazer presente nesse novo sujeito pelo restante de sua existência. Este artigo busca dar nova luz ao aspecto da transmissão psíquica transgeracional, diferenciando-se da recalque s abordagens psicanalíticas contemporâneas por ser uma leitura lacaniana. Serão usados dois exemplos: um de como a transmissão aparece na cultura, outro, na subjetividade do sujeito através da arte.

  18. The effect of laser power, traverse velocity and spot size on the peel resistance of a polypropylene/adhesive bond

    OpenAIRE

    Dowding, Colin; Dowding, Robert; Franceschini, Federica; Griffiths, Jonathan David

    2015-01-01

    Abstract The mean peel resistance force achieved with respect to variation in the laser power, incident spot traverse velocity and incident spot diameter between linear low density polyethylene film backed by a thin commercial adhesive coating that were bonded to a polypropylene substrate via thermal activation provided by a 27W CO 2 laser is discussed in this work. The results gathered for this work have been used to generate a novel empirical tool that predicts the CO...

  19. SNOW SURFACE FEATURES ALONG THE TRAVERSE ROUTE FROM THE COAST TO DOME FUJI STATION, QUEEN MAUD LAND, ANTARCTICA

    OpenAIRE

    フルカワ, テルオ; カミヤマ, コキチ; マエノ, ヒデオ; Teruo, Furukawa; Kokichi, Kamiyama; Hideo, MAENO

    1996-01-01

    Frequencies of snow surface features such as sastrugi, dunes and thermal cracks were measured along the traverse route from the coastal region to the summit of the Queen Maud Land ice sheet, Dome Fuji Station, East Antarctica. The study route can be clearly divided into three regions on the basis of the regional characteristics of snow surface features : coastal region, katabatic wind region and inland plateau region. The coastal region is characterized by high frequency of small sastrugi and...

  20. Efficient implementation of the 3D-DDA ray traversal algorithm on GPU and its application in radiation dose calculation.

    Science.gov (United States)

    Xiao, Kai; Chen, Danny Z; Hu, X Sharon; Zhou, Bo

    2012-12-01

    The three-dimensional digital differential analyzer (3D-DDA) algorithm is a widely used ray traversal method, which is also at the core of many convolution∕superposition (C∕S) dose calculation approaches. However, porting existing C∕S dose calculation methods onto graphics processing unit (GPU) has brought challenges to retaining the efficiency of this algorithm. In particular, straightforward implementation of the original 3D-DDA algorithm inflicts a lot of branch divergence which conflicts with the GPU programming model and leads to suboptimal performance. In this paper, an efficient GPU implementation of the 3D-DDA algorithm is proposed, which effectively reduces such branch divergence and improves performance of the C∕S dose calculation programs running on GPU. The main idea of the proposed method is to convert a number of conditional statements in the original 3D-DDA algorithm into a set of simple operations (e.g., arithmetic, comparison, and logic) which are better supported by the GPU architecture. To verify and demonstrate the performance improvement, this ray traversal method was integrated into a GPU-based collapsed cone convolution∕superposition (CCCS) dose calculation program. The proposed method has been tested using a water phantom and various clinical cases on an NVIDIA GTX570 GPU. The CCCS dose calculation program based on the efficient 3D-DDA ray traversal implementation runs 1.42 ∼ 2.67× faster than the one based on the original 3D-DDA implementation, without losing any accuracy. The results show that the proposed method can effectively reduce branch divergence in the original 3D-DDA ray traversal algorithm and improve the performance of the CCCS program running on GPU. Considering the wide utilization of the 3D-DDA algorithm, various applications can benefit from this implementation method.

  1. Obstacle traversal and self-righting of bio-inspired robots reveal the physics of multi-modal locomotion

    Science.gov (United States)

    Li, Chen; Fearing, Ronald; Full, Robert

    Most animals move in nature in a variety of locomotor modes. For example, to traverse obstacles like dense vegetation, cockroaches can climb over, push across, reorient their bodies to maneuver through slits, or even transition among these modes forming diverse locomotor pathways; if flipped over, they can also self-right using wings or legs to generate body pitch or roll. By contrast, most locomotion studies have focused on a single mode such as running, walking, or jumping, and robots are still far from capable of life-like, robust, multi-modal locomotion in the real world. Here, we present two recent studies using bio-inspired robots, together with new locomotion energy landscapes derived from locomotor-environment interaction physics, to begin to understand the physics of multi-modal locomotion. (1) Our experiment of a cockroach-inspired legged robot traversing grass-like beam obstacles reveals that, with a terradynamically ``streamlined'' rounded body like that of the insect, robot traversal becomes more probable by accessing locomotor pathways that overcome lower potential energy barriers. (2) Our experiment of a cockroach-inspired self-righting robot further suggests that body vibrations are crucial for exploring locomotion energy landscapes and reaching lower barrier pathways. Finally, we posit that our new framework of locomotion energy landscapes holds promise to better understand and predict multi-modal biological and robotic movement.

  2. Does biopsy needle traversing through central portion of lesion increase the risk of hemoptysis during percutaneous transthoracic needle biopsy?

    Science.gov (United States)

    Chen, Chia-Hung; Huang, Wei-Ming; Liang, Shih-Hsuan; Jhou, Zong-Yi; Chen, Chien-Wen; Chien, Yu-Chan; Lin, Hui-Chen; Wang, Chih-Hsin; Huang, Chun-Chao; Liao, Wei-Ni; Huang, Chung-Yao

    2018-01-19

    To evaluate whether traversal through the central part of a pulmonary lesion by a biopsy needle, and other factors, increases the risk of hemoptysis in patients undergoing CT-guided percutaneous transthoracic needle biopsy (PTNB). From July 2012 to November 2016, 227 patients undergoing 233 procedures were recruited as our study population. Patients were classified according to the occurrence of hemoptysis. Radiological assessments were performed by reviewing multiplanar reconstructed CT images. Other factors complicating PTNB-related hemoptysis were classified into (1) patient-related variables: age, gender, presence of emphysema; (2) lesion-related variables: size, location, distance to pleura, characteristics, presence of and degree of enhancement, histopathology of biopsy results; and (3) procedure-related variables: lesion depth, patient's body position. Twenty-two cases (9.4%) experienced hemoptysis. Univariate analysis revealed that subsolid lesions (p = 0.031) and lesion depth > 1 cm (p = 0.049) were risk factors. Traversal through the central part of the lesion by the biopsy needle was not a risk factor. Traversal through the central part of the lesion by the biopsy needle is not a risk factor of PTNB-related hemoptysis, but subsolid lesions and lesion depth > 1 cm increase the risk of hemoptysis.

  3. Multispot single-molecule FRET: High-throughput analysis of freely diffusing molecules.

    Directory of Open Access Journals (Sweden)

    Antonino Ingargiola

    Full Text Available We describe an 8-spot confocal setup for high-throughput smFRET assays and illustrate its performance with two characteristic experiments. First, measurements on a series of freely diffusing doubly-labeled dsDNA samples allow us to demonstrate that data acquired in multiple spots in parallel can be properly corrected and result in measured sample characteristics consistent with those obtained with a standard single-spot setup. We then take advantage of the higher throughput provided by parallel acquisition to address an outstanding question about the kinetics of the initial steps of bacterial RNA transcription. Our real-time kinetic analysis of promoter escape by bacterial RNA polymerase confirms results obtained by a more indirect route, shedding additional light on the initial steps of transcription. Finally, we discuss the advantages of our multispot setup, while pointing potential limitations of the current single laser excitation design, as well as analysis challenges and their solutions.

  4. Switching freely between superluminal and subluminal light propagation in a monolayer MoS2 nanoresonator.

    Science.gov (United States)

    Li, Jian-Bo; Xiao, Si; Liang, Shan; He, Meng-Dong; Kim, Nam-Chol; Luo, Yongfeng; Luo, Jian-Hua; Chen, Li-Qun

    2017-06-12

    We theoretically propose a feasible scheme to advance or slow the propagation of light in a monolayer MoS2 nanoresonator (NR). The scheme allows one to easily turn on or off the fast (superluminal) and slow (subluminal) light effects and switch freely between fast and slow light propagation by only adjusting the frequency or intensity of the pump field. As the exciton interacts strongly with the phonons in MoS2, the slow light effect will appear along with a large dispersion with a very steep negative slope and a sharp absorption peak. Especially, the maximal group velocity index of the slow light in the monolayer MoS2 NR can reach two orders of magnitude larger than that in a carbon nanotube resonator. These results provide a new way to measure the exciton-phonon coupling strength and may prove useful in device applications such as optical switching and optical signal processing.

  5. The organization of prospective thinking: evidence of event clusters in freely generated future thoughts.

    Science.gov (United States)

    Demblon, Julie; D'Argembeau, Arnaud

    2014-02-01

    Recent research suggests that many imagined future events are not represented in isolation, but instead are embedded in broader event sequences-referred to as event clusters. It remains unclear, however, whether the production of event clusters reflects the underlying organizational structure of prospective thinking or whether it is an artifact of the event-cuing task in which participants are explicitly required to provide chains of associated future events. To address this issue, the present study examined whether the occurrence of event clusters in prospective thought is apparent when people are left to think freely about events that might happen in their personal future. The results showed that the succession of events participants spontaneously produced when envisioning their future frequently included event clusters. This finding provides more compelling evidence that prospective thinking involves higher-order autobiographical knowledge structures that organize imagined events in coherent themes and sequences. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. A study of surface semi-geostrophic turbulence: freely decaying dynamics

    CERN Document Server

    Ragone, Francesco

    2015-01-01

    In this study we give a characterization of semi-geostrophic turbulence by performing freely decaying simulations of the semi-geostrophic equations for the case of constant uniform potential vorticity, a set of equations known as surface semi-geostrophic approximation. The equations are formulated as conservation laws for potential temperature and potential vorticity, with a nonlinear Monge-Amp\\'{e}re type inversion equation for the streamfunction, expressed in a transformed coordinate system that follows the geostrophic flow. We perform model studies of turbulent surface semi-geostrophic flows in a doubly-periodic domain in the horizontal limited in the vertical by two rigid lids, allowing for variations of potential temperature at one of the boundaries, and we compare them with the corresponding surface quasi-geostrophic case. Results show that, while surface quasi-geostrophic dynamics is dominated by a symmetric population of cyclones-anticyclones, surface semi-geostrophic dynamics features a prominent rol...

  7. An open access pilot freely sharing cancer genomic data from participants in Texas.

    Science.gov (United States)

    Becnel, Lauren B; Pereira, Stacey; Drummond, Jennifer A; Gingras, Marie-Claude; Covington, Kyle R; Kovar, Christie L; Doddapaneni, Harsha Vardhan; Hu, Jianhong; Muzny, Donna; McGuire, Amy L; Wheeler, David A; Gibbs, Richard A

    2016-02-16

    Genomic data sharing in cancer has been restricted to aggregate or controlled-access initiatives to protect the privacy of research participants. By limiting access to these data, it has been argued that the autonomy of individuals who decide to participate in data sharing efforts has been superseded and the utility of the data as research and educational tools reduced. In a pilot Open Access (OA) project from the CPRIT-funded Texas Cancer Research Biobank, many Texas cancer patients were willing to openly share genomic data from tumor and normal matched pair specimens. For the first time, genetic data from 7 human cancer cases with matched normal are freely available without requirement for data use agreements nor any major restriction except that end users cannot attempt to re-identify the participants (http://txcrb.org/open.html).

  8. Wireless stimulation of antennal muscles in freely flying hawkmoths leads to flight path changes.

    Science.gov (United States)

    Hinterwirth, Armin J; Medina, Billie; Lockey, Jacob; Otten, David; Voldman, Joel; Lang, Jeffrey H; Hildebrand, John G; Daniel, Thomas L

    2012-01-01

    Insect antennae are sensory organs involved in a variety of behaviors, sensing many different stimulus modalities. As mechanosensors, they are crucial for flight control in the hawkmoth Manduca sexta. One of their roles is to mediate compensatory reflexes of the abdomen in response to rotations of the body in the pitch axis. Abdominal motions, in turn, are a component of the steering mechanism for flying insects. Using a radio controlled, programmable, miniature stimulator, we show that ultra-low-current electrical stimulation of antennal muscles in freely-flying hawkmoths leads to repeatable, transient changes in the animals' pitch angle, as well as less predictable changes in flight speed and flight altitude. We postulate that by deflecting the antennae we indirectly stimulate mechanoreceptors at the base, which drive compensatory reflexes leading to changes in pitch attitude.

  9. The olfactory bulb theta rhythm follows all frequencies of diaphragmatic respiration in the freely behaving rat

    Directory of Open Access Journals (Sweden)

    Daniel eRojas-Líbano

    2014-06-01

    Full Text Available Sensory-motor relationships are part of the normal operation of sensory systems. Sensing occurs in the context of active sensor movement, which in turn influences sensory processing. We address such a process in the rat olfactory system. Through recordings of the diaphragm electromyogram (EMG, we monitored the motor output of the respiratory circuit involved in sniffing behavior, simultaneously with the local field potential (LFP of the olfactory bulb (OB in rats moving freely in a familiar environment, where they display a wide range of respiratory frequencies. We show that the OB LFP represents the sniff cycle with high reliability at every sniff frequency and can therefore be used to study the neural representation of motor drive in a sensory cortex.

  10. Transfer line from the PSB to the PS (recombination)

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    After sequential ejection of 5 bunches from each of the 4 rings of the Booster (originally 800 MeV, now 1.4 GeV), the 4 batches are brought to the same vertical level, so as to form a string of 20 bunches, filling the circumference of the PS. This vertical "recombination" is performed in the transfer line, using vertical bending magnets, septa and kickers. Here we see the section where the beam from ring 4 (the top one) is brought down to the level of ring 3, and the beam from ring 1 up to the level of ring 2. Further downstream (to the right, outside this picture), level 2 is brought up to level 3, identical to that of the PS. After this original recombination scheme, other ways of combining the 4 beams, vertically and/or longitudinally, were developed and used in operation.

  11. O Trabalho Psíquico da Intersubjetividade

    Directory of Open Access Journals (Sweden)

    Maria Inês Assumpção Fernandes

    2003-01-01

    Full Text Available O presente trabalho procura refletir sobre o trabalho psíquico da intersubjetividade nos grupos. Trata-se de pensá-lo na relação com a ruptura de investimentos durante o processo de Transformação x Criação, em primeiro lugar. A partir desse ponto, discutiremos a relação entre Transformação, Trabalho e Dispositivo. Neste caso pensamos nas possibilidades de intervenção, refletindo sobre a intervenção inpidual e a intervenção grupal. A questão da Transmissão Psíquica entre gerações será focalizada, fundamentalmente, no que se refere aos tempos lógicos do recalque.

  12. Images of Christ's Saving Work in Ps.-Epiphanius' Homilies

    Directory of Open Access Journals (Sweden)

    H. F. Stander

    1997-12-01

    Full Text Available Images of Christ's Saving Work in Ps.-Epiphanius' Homilies. One cannot really speak of a systematic theology on the subject of atone-ment in the patristic writers. Frances Young once said that 'it is in fact impossible to categorize neatly the thought of the major patristic writers on the subject of atonement'. She adds that one cannot do justice to the range of motifs and images that are found in describing the saving and atoning work of Christ if we merely dismember 'systematic theologies' to illustrate common soteriological themes. One can only appreciate patristic views of atonement if one begins by recognizing the multifaceted unity of imagery that pervades the literature. This then is the goal of this article: to discuss the rich images which Ps: -Epiphanius uses to describe the atoning work of Christ.

  13. Magnetoelectric MnPS3 as a candidate for ferrotoroidicity

    Science.gov (United States)

    Ressouche, E.; Loire, M.; Simonet, V.; Ballou, R.; Stunault, A.; Wildes, A.

    2010-09-01

    We have revisited the magnetic structure of manganese phosphorus trisulfide MnPS3 using neutron diffraction and polarimetry. MnPS3 undergoes a transition toward a collinear antiferromagnetic order at 78 K. The resulting magnetic point-group breaks both the time reversal and the space inversion thus allowing a linear magnetoelectric coupling. Neutron polarimetry was subsequently used to prove that this coupling provides a way to manipulate the antiferromagnetic domains simply by cooling the sample under crossed magnetic and electrical fields, in agreement with the nondiagonal form of the magnetoelectric tensor. In addition, this tensor has, in principle, an antisymmetric part that results in a toroidic moment and provides with a pure ferrotoroidic compound.

  14. PS Dreyer: Bakens op die pad van die wetenskap

    Directory of Open Access Journals (Sweden)

    A. J. Antonites

    1986-01-01

    Full Text Available PS Dreyer: Beacons on the path of science Professor PS Dreyer is an academic who has shown insight and vision into several problems of the human sciences since 1951. He has identified problems, but also contributed solutions to them. In this respect his philosophy on causality and freedom is of utmost importance. The same applies to his investigations into the relationship history-Christianity as well as the unity of sciences and how the concepts scientific, unscientic and nonscientific are related to one another. His contribution to the understanding of Greek philosophy should be of significance for time to come. Two milestones could be distinguished: Dreyer's particular solution to the problem of the criterion on truth, viz meaningfulness and his notion of the knowledge of values in ethics by valuation in contradistinction to knowledge through feeling, reason and will.

  15. Images of Christ's Saving Work in Ps.-Epiphanius' Homilies

    Directory of Open Access Journals (Sweden)

    H. F. Stander

    1997-01-01

    Full Text Available Images of Christ's Saving Work in Ps.-Epiphanius' Homilies. One cannot really speak of a systematic theology on the subject of atone-ment in the patristic writers. Frances Young once said that 'it is in fact impossible to categorize neatly the thought of the major patristic writers on the subject of atonement'. She adds that one cannot do justice to the range of motifs and images that are found in describing the saving and atoning work of Christ if we merely dismember 'systematic theologies' to illustrate common soteriological themes. One can only appreciate patristic views of atonement if one begins by recognizing the multifaceted unity of imagery that pervades the literature. This then is the goal of this article: to discuss the rich images which Ps: -Epiphanius uses to describe the atoning work of Christ.

  16. Longitudinal coupled-bunch instability studies in the PS

    CERN Document Server

    Damerau, H

    2017-01-01

    The main longitudinal limitation for LHC-type beams inthe PS are coupled-bunch instabilities. A dedicated proto-typefeedbacksystemusingaFinemetcavityasalongitudinalkicker has been installed. Extensive tests with beam havebeen performed to explore the intensity reach with this feed-back. The maximum intensity with nominal longitudinalemittance at PS extraction has been measured, as well as theemittance required to keep the beam longitudinally stableat the design intensity for the High-Luminosity LHC (HL-LHC). A higher-harmonic cavity is a complementary op-tion to extend the intensity reach beyond the capabilities ofthe coupled-bunch feedback. Preliminary machine develop-ment (MD) studies operating one20MHzor one40MHzRF system as a higher harmonic at the flat-top indicate thebeneficial effect on longitudinal beam stability

  17. Brain oscillations reflecting pain-related behavior in freely-moving rats.

    Science.gov (United States)

    Peng, W W; Xia, X L; Yi, M; Huang, G; Zhang, Z G; Iannetti, G D; Hu, L

    2017-09-25

    Recording oscillatory brain activity holds great promise in pain research. However, experimental results are variable and often difficult to reconcile. Some of these inconsistencies arise from the use of hypothesis-driven analysis approaches that do not assess the consistency of the observed responses within- and across-individuals, and do not fully exploit information sampled across the entire cortex. Here we address these issues by recording the electrocorticogram directly from the brain surface of 12 freely-moving rats. Using a hypothesis-free approach we isolated brain oscillations induced by graded nociceptive stimuli, and characterized their relation to pain-related behavior. We isolated four responses, one phase-locked event-related potential, two non-phase-locked event-related synchronizations (ERS), and one non-phase-locked desynchronization (ERD), in different frequency bands (δ/θ-ERD, θ/α-ERS, γ-ERS). All responses except the δ/θ-ERD correlated with pain-related behavior at within-subject level. Notably, the γ-ERS was the only response that reliably correlated with pain-related behavior between subjects. These results comprehensively characterize the physiological properties of the brain oscillations elicited by nociceptive stimuli in freely-moving rodents, and provide a foundational work to improve the translation of experimental animal findings to human physiology and pathophysiology.This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

  18. Rodent scope: a user-configurable digital wireless telemetry system for freely behaving animals.

    Science.gov (United States)

    Ball, David; Kliese, Russell; Windels, Francois; Nolan, Christopher; Stratton, Peter; Sah, Pankaj; Wiles, Janet

    2014-01-01

    This paper describes the design and implementation of a wireless neural telemetry system that enables new experimental paradigms, such as neural recordings during rodent navigation in large outdoor environments. RoSco, short for Rodent Scope, is a small lightweight user-configurable module suitable for digital wireless recording from freely behaving small animals. Due to the digital transmission technology, RoSco has advantages over most other wireless modules of noise immunity and online user-configurable settings. RoSco digitally transmits entire neural waveforms for 14 of 16 channels at 20 kHz with 8-bit encoding which are streamed to the PC as standard USB audio packets. Up to 31 RoSco wireless modules can coexist in the same environment on non-overlapping independent channels. The design has spatial diversity reception via two antennas, which makes wireless communication resilient to fading and obstacles. In comparison with most existing wireless systems, this system has online user-selectable independent gain control of each channel in 8 factors from 500 to 32,000 times, two selectable ground references from a subset of channels, selectable channel grounding to disable noisy electrodes, and selectable bandwidth suitable for action potentials (300 Hz-3 kHz) and low frequency field potentials (4 Hz-3 kHz). Indoor and outdoor recordings taken from freely behaving rodents are shown to be comparable to a commercial wired system in sorting for neural populations. The module has low input referred noise, battery life of 1.5 hours and transmission losses of 0.1% up to a range of 10 m.

  19. Rodent scope: a user-configurable digital wireless telemetry system for freely behaving animals.

    Directory of Open Access Journals (Sweden)

    David Ball

    Full Text Available This paper describes the design and implementation of a wireless neural telemetry system that enables new experimental paradigms, such as neural recordings during rodent navigation in large outdoor environments. RoSco, short for Rodent Scope, is a small lightweight user-configurable module suitable for digital wireless recording from freely behaving small animals. Due to the digital transmission technology, RoSco has advantages over most other wireless modules of noise immunity and online user-configurable settings. RoSco digitally transmits entire neural waveforms for 14 of 16 channels at 20 kHz with 8-bit encoding which are streamed to the PC as standard USB audio packets. Up to 31 RoSco wireless modules can coexist in the same environment on non-overlapping independent channels. The design has spatial diversity reception via two antennas, which makes wireless communication resilient to fading and obstacles. In comparison with most existing wireless systems, this system has online user-selectable independent gain control of each channel in 8 factors from 500 to 32,000 times, two selectable ground references from a subset of channels, selectable channel grounding to disable noisy electrodes, and selectable bandwidth suitable for action potentials (300 Hz-3 kHz and low frequency field potentials (4 Hz-3 kHz. Indoor and outdoor recordings taken from freely behaving rodents are shown to be comparable to a commercial wired system in sorting for neural populations. The module has low input referred noise, battery life of 1.5 hours and transmission losses of 0.1% up to a range of 10 m.

  20. A new rapid kindling variant for induction of cortical epileptogenesis in freely moving rats

    Directory of Open Access Journals (Sweden)

    Juan Carlos Morales

    2014-07-01

    Full Text Available Kindling, one of the most used models of experimental epilepsy is based on daily electrical stimulation in several brain structures. Unlike the classic or slow kindling protocols (SK, the rapid kindling types (RK described until now require continuous stimulation at suprathreshold intensities applied directly to the same brain structure used for subsequent electrophysiological and inmunohistochemical studies, usually the hippocampus. However, the cellular changes observed in these rapid protocols, such as astrogliosis and neuronal loss, could be due to experimental manipulation more than to epileptogenesis-related alterations. Here, we developed a new RK protocol in order to generate an improved model of temporal lobe epilepsy (TLE which allows gradual progression of the epilepsy as well as obtaining an epileptic hippocampus, thus avoiding direct surgical manipulation and electric stimulation over this structure. This new protocol consists of basolateral amygdala (BLA stimulation with 10 trains of biphasic pulses (10s;50Hz per day with 20 minutes-intervals, during 3 consecutive days, using a subconvulsive and subthreshold intensity, which guarantees tissue integrity. The progression of epileptic activity was evaluated in freely moving rats through EEG recordings from cortex and amygdala, accompanied with synchronized video recordings. Moreover, we assessed the effectiveness of RK protocol and the establishment of epilepsy by evaluating cellular alterations of hippocampal slices from kindled rats. RK protocol induced convulsive states similar to SK protocols but in 3 days, with persistently lowered threshold to seizure induction and epileptogenic-dependent cellular changes in amygdala projection areas. We concluded that this novel RK protocol introduces a new variant of the chronic epileptogenesis models in freely moving rats, which is faster, highly reproducible and causes minimum cell damage with respect to that observed in other experimental

  1. Limited drug solubility can be decisive even for freely soluble drugs in highly swollen matrix tablets.

    Science.gov (United States)

    Siepmann, F; Karrout, Y; Gehrke, M; Penz, F K; Siepmann, J

    2017-06-30

    The aim of this study was to elucidate the importance of potential limited solubility effects for the control of drug release from hydrophilic matrix tablets loaded with a freely water-soluble drug. It is often assumed that the considerable amounts of water penetrating into this type of advanced drug delivery systems are sufficient to rapidly dissolve the entire drug loading, and that limited drug solubility is not playing a role for the control of drug release. Here, we show that this assumption can be erroneous. HPMC/lactose matrix tablets were loaded with 5 to 60% diprophylline (e.g. solubility in 0.1M HCl at 37°C: 235mg/mL), and drug release was measured at low and neutral pH, respectively. A mechanistically realistic mathematical theory was applied, considering drug diffusion in axial and radial direction in the cylindrical matrices and the potential co-existence of dissolved and non-dissolved drug. Importantly, only dissolved drug is available for diffusion. It is demonstrated that during major parts of the release periods, non-dissolved drug excess exists within tablets containing 30% or more diprophylline, despite of the substantial water contents of the systems. This leads to partially almost linear drug concentration distance profiles within the tablets, and reveals a major contribution of limited drug solubility effects to the control of drug release, even in the case of freely water-soluble diprophylline. It can be expected that also in other types of drug delivery systems, e.g. microparticles and implants (containing much less water), limited drug solubility effects play a much more important role than currently recognized. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Passive sampling methods for contaminated sediments: Scientific rationale supporting use of freely dissolved concentrations

    Science.gov (United States)

    Mayer, Philipp; Parkerton, Thomas F; Adams, Rachel G; Cargill, John G; Gan, Jay; Gouin, Todd; Gschwend, Philip M; Hawthorne, Steven B; Helm, Paul; Witt, Gesine; You, Jing; Escher, Beate I

    2014-01-01

    Passive sampling methods (PSMs) allow the quantification of the freely dissolved concentration (Cfree) of an organic contaminant even in complex matrices such as sediments. Cfree is directly related to a contaminant's chemical activity, which drives spontaneous processes including diffusive uptake into benthic organisms and exchange with the overlying water column. Consequently, Cfree provides a more relevant dose metric than total sediment concentration. Recent developments in PSMs have significantly improved our ability to reliably measure even very low levels of Cfree. Application of PSMs in sediments is preferably conducted in the equilibrium regime, where freely dissolved concentrations in the sediment are well-linked to the measured concentration in the sampler via analyte-specific partition ratios. The equilibrium condition can then be assured by measuring a time series or a single time point using passive samplers with different surface to volume ratios. Sampling in the kinetic regime is also possible and generally involves the application of performance reference compounds for the calibration. Based on previous research on hydrophobic organic contaminants, it is concluded that Cfree allows a direct assessment of 1) contaminant exchange and equilibrium status between sediment and overlying water, 2) benthic bioaccumulation, and 3) potential toxicity to benthic organisms. Thus, the use of PSMs to measure Cfree provides an improved basis for the mechanistic understanding of fate and transport processes in sediments and has the potential to significantly improve risk assessment and management of contaminated sediments. Integr Environ Assess Manag 2014;10:197–209. © 2014 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of SETAC. PMID:24288295

  3. An Ambulatory Electroencephalography System for Freely Moving Horses: An Innovating Approach

    Directory of Open Access Journals (Sweden)

    Hugo Cousillas

    2017-05-01

    Full Text Available Electroencephalography (EEG that has been extensively studied in humans presents also a large interest for studies on animal brain processes. However, since the quality of the recordings is altered by muscular activity, most EEG recordings on animals are obtained using invasive methods with deeply implanted electrodes. This requires anesthesia and can thus only be used in laboratory or clinical settings. As EEG is a very useful tool both for detecting brain alterations due to diseases or accidents and to evaluate the arousal and attentional state of the animal, it seemed crucial to develop a tool that would make such recordings possible in the horse’s home environment, with a freely moving horse. Such a tool should neither be invasive nor cause discomforts to the horse as the usual other practice which consists, after shaving the zone, in gluing the electrodes to the skin. To fulfill these requirements, we developed a novel EEG headset adapted to the horse’s head that allows an easy and fast positioning of the electrodes and that can be used in the home environment on a freely moving horse. In this study, we show that this EEG headset allows to obtain reliable recordings, and we propose an original evaluation of an animal’s “EEG profile” that allows comparisons between individuals and situations. This EEG headset opens new possibilities of investigation on horse cognition, and it can also become a useful tool for veterinarians to evaluate cerebral disorders or check the anesthesia level during a surgery.

  4. Functional characterization of calcineurin homologs PsCNA1/PsCNB1 in Puccinia striiformis f. sp. tritici using a host-induced RNAi system.

    Directory of Open Access Journals (Sweden)

    Hong Zhang

    Full Text Available Calcineurin plays a key role in morphogenesis, pathogenesis and drug resistance in most fungi. However, the function of calcineurin genes in Puccinia striiformis f. sp. tritici (Pst is unclear. We identified and characterized the calcineurin genes PsCNA1 and PsCNB1 in Pst. Phylogenetic analyses indicate that PsCNA1 and PsCNB1 form a calcium/calmodulin regulated protein phosphatase belonging to the calcineurin heterodimers composed of subunits A and B. Quantitative RT-PCR analyses revealed that both PsCNA1 and PsCNB1 expression reached their maximum in the stage of haustorium formation, which is one day after inoculation. Using barely stripe mosaic virus (BSMV as a transient expression vector in wheat, the expression of PsCNA1 and PsCNB1 in Pst was suppressed, leading to slower extension of fungal hyphae and reduced production of urediospores. The immune-suppressive drugs cyclosporin A and FK506 markedly reduced the germination rates of urediospores, and when germination did occur, more than two germtubes were produced. These results suggest that the calcineurin signaling pathway participates in stripe rust morphogenetic differentiation, especially the formation of haustoria during the early stage of infection and during the production of urediospores. Therefore PsCNA1 and PsCNB1 can be considered important pathogenicity genes involved in the wheat-Pst interaction.

  5. Consolidation of the 45-Year Old PS Main Magnet System

    CERN Document Server

    Zickler, Thomas; Kalbreier, Wilhelm; Mess, Karl Hubert; Newborough, Antony

    2006-01-01

    After a major coil insulation breakdown on two of the 47-year-old CERN PS main magnets in 2003, an extensive magnet consolidation program has been launched. This article reviews the analysis of the magnet state be-fore the repair and the applied major improvements. An overview is given of the production of the new compo-nents, the actual refurbishment and the commissioning of the main magnet system after 18 months shutdown.

  6. Specification of the Beam Position Measurement in the PS Machine

    CERN Document Server

    Bravin, Enrico; Chanel, M; Ludwig, M; Métral, Elias; Métral, G; Potier, J P; Raich, U; Scrivens, R; Steerenberg, R; CERN. Geneva. AB Department

    2003-01-01

    This specification, drawn up by the instrumentation specification board 2, describes the requirements concerning orbit and trajectory measurements in the PS machine. The orbit measurement and the trajectory measurement are both indispensable in order to be able to guarantee the correct beam quality for beams like LHC, the future Grand Sasso beam, the nTOF beam and surely the combined operation of the nTOF beam and the East Area beam.

  7. Science spin: iPS cell research in the news.

    Science.gov (United States)

    Caulfield, T; Rachul, C

    2011-05-01

    Big scientific developments have always been spun to meet particular social agendas. We have seen it in the context of global warming, nuclear power, and genetically modified organisms. But few stories illustrate the phenomenon of spin as well as the reaction, and concomitant media coverage, that surrounded the November 2007 announcement regarding the reprogramming of skin cells to produce cells with qualities comparable to those of human embryonic stem cells (hESCs) known as induced pluripotent stem (iPS) cells.

  8. Physics at the AD/PS/SPS (1/4)

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Lecture 1: The CERN injector complex and beams for non-LHC physics. The various machines and beam lines in the CERN injector complex are presented, from the linacs to the SPS. Special emphasis is given to the beam lines at the PS and SPS machines: AD, North and East Areas, nTOF and CNGS and HiRadMad as well as the ion beams. A short outlook is given to possible future upgrades and projects.

  9. Ps18.pdf | sep2002 | jess | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; jess; sep2002; Ps18.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Associates – 2017. Posted on 17 July 2017. Click here to see the list · 28th Mid Year Meeting. Posted on 26 May ...

  10. New Electron Cloud Detectors for the PS Main Magnets

    CERN Document Server

    Yin Vallgren, Ch; Gilardoni, S; Taborelli, M; Neupert, H; Ferreira Somoza, J

    2014-01-01

    Electron cloud (EC) has already been observed during normal operation of the PS, therefore it is necessary to study its in fluence on any beam instability for the future LHC Injector Upgrade (LIU). Two new electron cloud detectors have been discussed, developed and installed during the Long Shutdown (LS1) in one of the PS main magnets. The first measurement method is based on current measurement by using a shielded button-type pick-up. Due to the geometry and space limitation in the PS magnet, the button-type pick-up made of a 96%Al2O3 block coated with a thin layer of solvent-based Ag painting, placed 30 degrees to the bottom part of the vacuum chamber was installed in the horizontal direction where the only opening of the magnet coil is. The other newly developed measurement method is based on detection of photons emitted by the electrons from the electron cloud impinging on the vacuum chamber walls. The emitted photons are reected to a quartz window. A MCP-PMT (Micro-Channel Plate Photomultiplier Tube) wit...

  11. LS1 Report: PS Booster prepares for beam

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    With Linac2 already up and running, the countdown to beam in the LHC has begun! The next in line is the PS Booster, which will close up shop to engineers early next week. The injector will be handed over to the Operations Group who are tasked with getting it ready for active duty.   Taken as we approach the end of LS1 activities, this image shows where protons will soon be injected from Linac2 into the four PS Booster rings. Over the coming two months, the Operations Group will be putting the Booster's new elements through their paces. "Because of the wide range of upgrades and repairs carried out in the Booster, we have a very full schedule of tests planned for the machine," says Bettina Mikulec, PS Booster Engineer in Charge. "We will begin with cold checks; these are a wide range of tests carried out without beam, including system tests with power on/off and with varying settings, as well as verification of the controls system and timings." Amon...

  12. Kultuur isiksuse psühholoogiat ei mõjuta / Tiit Kändler

    Index Scriptorium Estoniae

    Kändler, Tiit, 1948-

    2010-01-01

    Psühholoogia uuemate andmete kohaselt ei sõltu indiviidi seadumus kultuurist, soost, vanusest, haridusest. Eesti psühholoogide Jüri Alliku ja Ann Realo osalusel ajakirjas "Journal Personality and Social Psychology" ilmunud artiklist

  13. Kultuur isiksuse psühholoogiat ei mõjuta / Tiit Kändler

    Index Scriptorium Estoniae

    Kändler, Tiit, 1948-

    2005-01-01

    Psühholoogia uuemate andmete kohaselt ei sõltu indiviidi seadumus kultuurist, soost, vanusest, haridusest. Eesti psühholoogide Jüri Alliku ja Anu Realo osalusel ajakirjas "Journal Personality and Social Psychology" ilmunud artiklist

  14. A novel detachable head-mounted device for simultaneous EEG and photoacoustic monitoring of epilepsy in freely moving rats.

    Science.gov (United States)

    Wang, Bo; Zhou, Junli; Carney, Paul; Jiang, Huabei

    2015-02-01

    The study of neuro-hemodynamic changes in freely moving animals provides for a better understanding of brain dynamics in normal and disease states. While it has been shown that hemodynamic changes are closely related to seizures, methods for detection in freely moving animals are limited. In this work, we integrate photoacoustic sensor technology and electroencephalography into a small portable device that can be attached on the head of wake freely moving animals. We demonstrate chronic simultaneous monitoring of photoacoustic and electroencephalographic signals in an acute seizure model of epilepsy. Our results demonstrate that both the neural and vascular responses during seizures in freely moving rats have characteristics which are observed to be different and more diverse from that of anesthetized rats. This implies that the neurovascular coupling in seizure in free moving animals are more complicated, which calls for more detailed study in future. To the best of our knowledge, this is the first time for hemodynamic monitoring of seizure in free moving animals. This technology also promises for other hemodynamic related research study in freely moving small animals. Copyright © 2014. Published by Elsevier Ireland Ltd.

  15. Comparative, validity and responsiveness of the HOOS-PS and KOOS-PS to the WOMAC physical function subscale in total joint replacement for osteoarthritis

    DEFF Research Database (Denmark)

    Davis, A M; Perruccio, A V; Canizares, M

    2009-01-01

    OBJECTIVE: To evaluate the internal consistency of the Hip disability and Osteoarthritis Outcome Score-Physical Function Short-form (HOOS-PS) and the Knee injury and Osteoarthritis Outcome Score-Physical Function Short-form (KOOS-PS) in total hip replacement (THR) and total knee (TKR) replacement....... Construct validity and responsiveness were compared to the Western Ontario McMaster Universities' Osteoarthritis Index (WOMAC) Likert 3.0 physical function (PF) subscale and the PF excluding the items in the short measures (PF-exclusions). METHODS: Participants completed the full HOOS or KOOS, measures...... of fatigue, anxiety, depression and the Chronic Pain Grade (CPG) pre-surgery and the HOOS or KOOS 6 months post-surgery. Internal consistency for the HOOS-PS and KOOS-PS was calculated using Cronbach's alpha. For construct validity, it was hypothesized that correlations between the HOOS-PS or KOOS-PS and PF...

  16. Analüütilised voolud psühholoogias ja nende rakendamine pedagoogikas / Aleksander Elango

    Index Scriptorium Estoniae

    Elango, Aleksander, 1902-2004

    2001-01-01

    Analüütise psühholoogia kolm koolkonda - S.Freudì koolkond e. päris-psühhoanalüüs, A.Adlerì koolkond e. individuaalpsühholoogia ja C.G.Jungì psühhoanalüüsi ja individuaalpsühholoogia sünteesi luua püüdev koolkond. Analüütise psühholoogia koolkondade ja pedagoogika suhetest

  17. File list: His.PSC.05.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.PSC.05.AllAg.iPS_cells hg19 Histone Pluripotent stem cell iPS cells SRX317576,S...077,SRX317607 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.PSC.05.AllAg.iPS_cells.bed ...

  18. File list: His.PSC.50.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  19. File list: ALL.PSC.50.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  20. File list: His.PSC.10.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  1. File list: ALL.PSC.20.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  3. File list: Pol.PSC.20.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  4. File list: ALL.PSC.05.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  5. File list: Pol.PSC.10.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  6. File list: ALL.PSC.05.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  7. File list: Oth.PSC.50.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.PSC.50.AllAg.iPS_cells mm9 TFs and others Pluripotent stem cell iPS cells SRX97...RX146524 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.PSC.50.AllAg.iPS_cells.bed ...

  8. File list: Pol.PSC.50.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.PSC.50.AllAg.iPS_cells mm9 RNA polymerase Pluripotent stem cell iPS cells SRX97...7435,SRX977434,SRX027462 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.PSC.50.AllAg.iPS_cells.bed ...

  9. File list: DNS.PSC.20.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.PSC.20.AllAg.iPS_cells hg19 DNase-seq Pluripotent stem cell iPS cells SRX040379...,SRX040378,SRX135563,SRX040377,SRX040376,SRX189427,SRX189400,SRX189399 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/DNS.PSC.20.AllAg.iPS_cells.bed ...

  10. File list: DNS.PSC.10.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.PSC.10.AllAg.iPS_cells hg19 DNase-seq Pluripotent stem cell iPS cells SRX040379...,SRX040378,SRX040377,SRX040376,SRX135563,SRX189427,SRX189400,SRX189399 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/DNS.PSC.10.AllAg.iPS_cells.bed ...

  11. File list: Pol.PSC.05.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.PSC.05.AllAg.iPS_cells mm9 RNA polymerase Pluripotent stem cell iPS cells SRX97...7435,SRX027462,SRX977434 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.PSC.05.AllAg.iPS_cells.bed ...

  12. File list: ALL.PSC.10.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.PSC.10.AllAg.iPS_cells hg19 All antigens Pluripotent stem cell iPS cells SRX753...09,SRX189400,SRX189399 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.PSC.10.AllAg.iPS_cells.bed ...

  13. File list: His.PSC.10.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.PSC.10.AllAg.iPS_cells mm9 Histone Pluripotent stem cell iPS cells SRX977417,SR...RX127372,SRX1090869,SRX127376,SRX035977,SRX146530,SRX146547,SRX146522 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.PSC.10.AllAg.iPS_cells.bed ...

  14. File list: Oth.PSC.20.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.PSC.20.AllAg.iPS_cells mm9 TFs and others Pluripotent stem cell iPS cells SRX97...RX146524 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.PSC.20.AllAg.iPS_cells.bed ...

  15. File list: DNS.PSC.05.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.PSC.05.AllAg.iPS_cells hg19 DNase-seq Pluripotent stem cell iPS cells SRX040379...,SRX040378,SRX040377,SRX040376,SRX135563,SRX189427,SRX189400,SRX189399 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/DNS.PSC.05.AllAg.iPS_cells.bed ...

  16. File list: His.PSC.20.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.PSC.20.AllAg.iPS_cells mm9 Histone Pluripotent stem cell iPS cells SRX127389,SR...RX127372,SRX127373,SRX1090869,SRX127376,SRX146530,SRX146522,SRX146547 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.PSC.20.AllAg.iPS_cells.bed ...

  17. Genomic imprinting is variably lost during reprogramming of mouse iPS cells.

    Science.gov (United States)

    Takikawa, Sachiko; Ray, Chelsea; Wang, Xin; Shamis, Yulia; Wu, Tien-Yuan; Li, Xiajun

    2013-09-01

    Derivation of induced pluripotent stem (iPS) cells is mainly an epigenetic reprogramming process. It is still quite controversial how genomic imprinting is reprogrammed in iPS cells. Thus, we derived multiple iPS clones from genetically identical mouse somatic cells. We found that parentally inherited imprint was variably lost among these iPS clones. Concurrent with the loss of DNA methylation imprint at the corresponding Snrpn and Peg3 imprinted regions, parental origin-specific expression of the Snrpn and Zim1 imprinted genes was also lost in these iPS clones. This loss of parental genomic imprinting in iPS cells was likely caused by the reprogramming process during iPS cell derivation because extended culture of iPS cells did not lead to significant increase in the loss of genomic imprinting. Intriguingly, one to several paternal chromosomes appeared to have acquired de novo methylation at the Snrpn and Zac1 imprinted regions in a high percentage of iPS clones. These results might have some implications for future therapeutic applications of iPS cells. Since DNA methylation imprint can be completely erased in some iPS clones at multiple imprinted regions, iPS cell reprogramming may also be employed to dissect the underlying mechanisms of erasure, reacquisition and maintenance of genomic imprinting in mammals. Copyright © 2013. Published by Elsevier B.V.

  18. File list: Oth.PSC.10.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.PSC.10.AllAg.iPS_cells mm9 TFs and others Pluripotent stem cell iPS cells SRX65...RX146524 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.PSC.10.AllAg.iPS_cells.bed ...

  19. File list: His.PSC.05.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.PSC.05.AllAg.iPS_cells mm9 Histone Pluripotent stem cell iPS cells SRX977417,SR...RX127374,SRX127373,SRX1090869,SRX333561,SRX146530,SRX146522,SRX146547 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.PSC.05.AllAg.iPS_cells.bed ...

  20. File list: ALL.PSC.10.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.PSC.10.AllAg.iPS_cells mm9 All antigens Pluripotent stem cell iPS cells SRX9774...30,SRX146524,SRX146547,SRX146522 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.PSC.10.AllAg.iPS_cells.bed ...

  1. File list: ALL.PSC.50.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.PSC.50.AllAg.iPS_cells mm9 All antigens Pluripotent stem cell iPS cells SRX9773...1,SRX035985,SRX1090869 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.PSC.50.AllAg.iPS_cells.bed ...

  2. File list: ALL.PSC.20.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.PSC.20.AllAg.iPS_cells mm9 All antigens Pluripotent stem cell iPS cells SRX9773...30,SRX146522,SRX146547 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.PSC.20.AllAg.iPS_cells.bed ...

  3. File list: His.PSC.20.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.PSC.20.AllAg.iPS_cells hg19 Histone Pluripotent stem cell iPS cells SRX110015,S...315,SRX381309 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.PSC.20.AllAg.iPS_cells.bed ...

  4. File list: Oth.PSC.05.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.PSC.05.AllAg.iPS_cells mm9 TFs and others Pluripotent stem cell iPS cells SRX65...RX146524 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.PSC.05.AllAg.iPS_cells.bed ...

  5. File list: DNS.PSC.50.AllAg.iPS_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.PSC.50.AllAg.iPS_cells hg19 DNase-seq Pluripotent stem cell iPS cells SRX040379...,SRX040378,SRX135563,SRX040376,SRX040377,SRX189427,SRX189400,SRX189399 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/DNS.PSC.50.AllAg.iPS_cells.bed ...

  6. Ser-261 phospho-regulation is involved in pS256 and pS269-mediated aquaporin-2 apical translocation.

    Science.gov (United States)

    Yui, Naofumi; Ando, Fumiaki; Sasaki, Sei; Uchida, Shinichi

    2017-08-26

    Vasopressin catalyzes aquaporin-2 phosphorylation at several serine sites in the C-terminal region. Compared with Ser-256 and Ser-269 phosphorylation, the role of Ser-261 phospho-regulation on vasopressin-regulated AQP2 apical translocation is largely unknown. In addition, recent discovery of transcytotic apical delivery of AQP2 made the concept of its intracellular trafficking even more complicated. In this study, we evaluated how intact phospho-AQP2 signals fit with the transcytosis trafficking model in Madin-Darby canine kidney cells. PS256 and pS269 signals were intracellularly detectable in wild-type AQP2 at the beginning of forskolin stimulation (1 min). These phospho-signals were detectable in basolateral membranes even after 10 min of stimulation. AQP2 stably inserted in the apical membrane increased pS269 and decreased pS261 signals. In an NDI-causing mutant P262L-AQP2, in which Ser-261 phospho-regulation is impaired, the pS256 and pS269 signals were detectable in the basolateral membranes with increased pS261 signals after forskolin stimulation. These results suggest that Ser-261 phospho-regulation is involved in pS256- and pS269-mediated AQP2 apical translocation. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Spatial cognition in a virtual reality home-cage extension for freely moving rodents.

    Science.gov (United States)

    Kaupert, Ursula; Thurley, Kay; Frei, Katja; Bagorda, Francesco; Schatz, Alexej; Tocker, Gilad; Rapoport, Sophie; Derdikman, Dori; Winter, York

    2017-04-01

    Virtual reality (VR) environments are a powerful tool to investigate brain mechanisms involved in the behavior of animals. With this technique, animals are usually head fixed or secured in a harness, and training for cognitively more complex VR paradigms is time consuming. A VR apparatus allowing free animal movement and the constant operator-independent training of tasks would enable many new applications. Key prospective usages include brain imaging of animal behavior when carrying a miniaturized mobile device such as a fluorescence microscope or an optetrode. Here, we introduce the Servoball, a spherical VR treadmill based on the closed-loop tracking of a freely moving animal and feedback counterrotation of the ball. Furthermore, we present the complete integration of this experimental system with the animals' group home cage, from which single individuals can voluntarily enter through a tunnel with radio-frequency identification (RFID)-automated access control and commence experiments. This automated animal sorter functions as a mechanical replacement of the experimenter. We automatically trained rats using visual or acoustic cues to solve spatial cognitive tasks and recorded spatially modulated entorhinal cells. When electrophysiological extracellular recordings from awake behaving rats were performed, head fixation can dramatically alter results, so that any complex behavior that requires head movement is impossible to achieve. We circumvented this problem with the use of the Servoball in open-field scenarios, as it allows the combination of open-field behavior with the recording of nerve cells, along with all the flexibility that a virtual environment brings. This integrated home cage with a VR arena experimental system permits highly efficient experimentation for complex cognitive experiments. NEW & NOTEWORTHY Virtual reality (VR) environments are a powerful tool for the investigation of brain mechanisms. We introduce the Servoball, a VR treadmill for

  8. Microbial methanogenesis in the sulfate-reducing zone of surface sediments traversing the Peruvian margin

    Science.gov (United States)

    Maltby, J.; Sommer, S.; Dale, A. W.; Treude, T.

    2016-01-01

    We studied the concurrence of methanogenesis and sulfate reduction in surface sediments (0-25 cm below sea floor) at six stations (70, 145, 253, 407, 990 and 1024 m) along the Peruvian margin (12° S). This oceanographic region is characterized by high carbon export to the seafloor creating an extensive oxygen minimum zone (OMZ) on the shelf, both factors that could favor surface methanogenesis. Sediments sampled along the depth transect traversed areas of anoxic and oxic conditions in the bottom-near water. Net methane production (batch incubations) and sulfate reduction (35S-sulfate radiotracer incubation) were determined in the upper 0-25 cm b.s.f. of multiple cores from all stations, while deep hydrogenotrophic methanogenesis (> 30 cm b.s.f., 14C-bicarbonate radiotracer incubation) was determined in two gravity cores at selected sites (78 and 407 m). Furthermore, stimulation (methanol addition) and inhibition (molybdate addition) experiments were carried out to investigate the relationship between sulfate reduction and methanogenesis.Highest rates of methanogenesis and sulfate reduction in the surface sediments, integrated over 0-25 cm b.s.f., were observed on the shelf (70-253 m, 0.06-0.1 and 0.5-4.7 mmol m-2 d-1, respectively), while lowest rates were discovered at the deepest site (1024 m, 0.03 and 0.2 mmol m-2 d-1, respectively). The addition of methanol resulted in significantly higher surface methanogenesis activity, suggesting that the process was mostly based on non-competitive substrates - i.e., substrates not used by sulfate reducers. In the deeper sediment horizons, where competition was probably relieved due to the decrease of sulfate, the usage of competitive substrates was confirmed by the detection of hydrogenotrophic activity in the sulfate-depleted zone at the shallow shelf station (70 m).Surface methanogenesis appeared to be correlated to the availability of labile organic matter (C / N ratio) and organic carbon degradation (DIC production

  9. Create and Publish a Hierarchical Progressive Survey (HiPS)

    Science.gov (United States)

    Fernique, P.; Boch, T.; Pineau, F.; Oberto, A.

    2014-05-01

    Since 2009, the CDS promotes a method for visualizing based on the HEALPix sky tessellation. This method, called “Hierarchical Progressive Survey" or HiPS, allows one to display a survey progressively. It is particularly suited for all-sky surveys or deep fields. This visualization method is now integrated in several applications, notably Aladin, the SiTools/MIZAR CNES framework, and the recent HTML5 “Aladin Lite". Also, more than one hundred surveys are already available in this view mode. In this article, we will present the progress concerning this method and its recent adaptation to the astronomical catalogs such as the GAIA simulation.

  10. Electrostatic septum for "Continuous Transfer" from PS to SPS

    CERN Multimedia

    CERN PhotoLab

    1982-01-01

    For "Continuous Transfer" to the SPS, the PS beam, after acceleration, is peeled off in 5 turns. To minimize losses, the magnetic septa are preceded by an electrostatic septum in straight section 31. We see the inner part of it, on a lab-bench. The first part consists of W-wires, the second part is a Mo-foil. The circulating beam passes through the opening, the ejected beam at the outside (above the wires, in this picture). This assembly is the anode-part, the cathode is not shown.

  11. Beam Quality Preservation in the CERN PS-SPS Complex

    CERN Multimedia

    Arduini, Gianluigi

    2004-01-01

    The LHC will require beams of unprecedented transverse and longitudinal brightness. Their production imposes tight constraints on the emittance growth in each element of the LHC injector chain, namely the PS-SPS Accelerator Complex. The problems encountered at the different stages of the acceleration in the complex span a wide range of topics, such as injection matching, RF gymnastics, space charge, transverse and longitudinal single- and coupled-bunch instabilities, and electron cloud effects. The measurement techniques developed and applied to identify and study the various sources of emittance dilution to the high precision required for the LHC beams and the solutions found to control such phenomena are illustrated.

  12. Lo irreductible social y lo irreductible psíquico

    Directory of Open Access Journals (Sweden)

    Vincent Gaulejac, de

    2017-06-01

    Full Text Available Con base en la reconstrucción de las polaridades explicativas -lo irreductible social y lo irreductible psíquico-que atraviesan a las ciencias sociales, este texto propone trascender los modelos antagónicos y excluyentes. El objetivo es instaurar en el centro de la reflexión la idea de la dialktica existencial que restituye al sujeto tanto el contexto socio-histórico en el cual está localizado como el deseo y la singularidad que lo constituyen en productor de la afirmación de su individualidad y su historicidad.

  13. PS potential performance with a higher injection energy

    CERN Document Server

    Gilardoni, S; Borburgh, J; Bodart, D; Chiggiato, P; Damerau, H; Hancock, S; Metral, G; Pittet, S; Rossi, C; Rumolo, G; Steerenberg, R; Widorski, M

    2011-01-01

    In the context of the LHC Injectors upgrade project, the PS has to be brought up to − and to operate reliably at − the level of performance required by the HL-LHC until the end of the LHC lifetime. The study has started on the potential benefits of increasing the injection energy. An overview of the impact of this upgrade will be presented, with a preliminary estimate of the beam characteristics at the SPS entrance and the remaining performance limitations. The necessary hardware modifications will be described, highlighting the critical systems and the risks. The program for the 2011 machine studies and hardware interventions for refining these plans will be presented.

  14. Injection and transfer lines of the PS Booster

    CERN Multimedia

    Photographic Service

    1972-01-01

    In the foreground is the vacuum chamber for the 50 MeV proton beam coming from the Linac. The tank held by white frames houses the "Vertical Distributor", which deflects the Linac beam to the levels of the Booster's 4 superposed rings. After acceleration in the Booster, originally to 800 MeV, today to 1.4 GeV, the beams from the 4 rings are combined in the vertical plane and transfered to the 26 GeV PS. The "Recombination Line", intersecting the injection line, crosses the picture from left to right.

  15. Search for Decays of Heavy Neutrinos with the PS Beam

    CERN Multimedia

    2002-01-01

    The experiment searches for neutrino decay, primarily into the e|+e|-@n^e and @g@g@n^e modes. Neutrino masses in the region between 1 and 400~MeV will be explored. The beam used is the neutrino PS beam used for the oscillation experiments. The apparatus consists of a decay volume @=30~m long and a calorimeter @=8~radiation lengths thick and @=20~m|2 in surface. The detectors are flash-tube modules of the type developed at Saclay for the proton-stability experiment. Scintillator hodoscopes give the timing information necessary for the trigger logic and background rejection.

  16. Reliability and maintenance analysis of the CERN PS booster

    CERN Document Server

    Staff, P S B

    1977-01-01

    The PS Booster Synchrotron being a complex accelerator with four superposed rings and substantial additional equipment for beam splitting and recombination, doubts were expressed at the time of project authorization as to its likely operational reliability. For 1975 and 1976, the average down time was 3.2% (at least one ring off) or 1.5% (all four rings off). The items analysed are: operational record, design features, maintenance, spare parts policy, operating temperature, effects of thunderstorms, fault diagnostics, role of operations staff and action by experts. (15 refs).

  17. Viscometric characterization of PS/POSS hybrid nanocomposites

    OpenAIRE

    Bianchi, Otávio; Repenning, Gustavo B.; Mauler, Raquel S.; Oliveira, Ricardo V. B.; Canto, Leonardo B.

    2012-01-01

    Nanocompósitos híbridos de poliestireno (PS) e poliedros oligoméricos silsesquioxanos (POSS) com diferentes composições e graus de hibridização foram obtidos por processamento reativo no estado fundido utilizando-se peróxido de dicumila (DCP) como iniciador, na presença ou não de estireno como agente de transferência de radical. Os materiais foram caracterizados viscosimetricamente por cromatografia de permeação em gel (GPC) usando detecção tripla por espalhamento de luz, viscosimetria e índi...

  18. A multiturn measurement system for the CERN PS

    CERN Document Server

    Angoletta, Maria Elena

    2002-01-01

    Multiturn beam position measurements on one or more pickups provide very important information needed to derive machine optics parameters. A variety of analyses is possible, such as determination of phase advance, detuning with amplitude, and most important, the exploration of phase space. In this paper we present a new multiturn acquisition system for the CERN proton synchrotron (CERN PS) based on a compact PCI fast digitiser and a new general object-oriented visualisation and analysis tool for the acquired multiturn data. (11 refs).

  19. Behavioral and metabolic contributions to thermoregulation in freely swimming leatherback turtles at high latitudes.

    Science.gov (United States)

    Casey, James P; James, Michael C; Williard, Amanda S

    2014-07-01

    Leatherback turtles in the Northwest Atlantic Ocean have a broad geographic range that extends from nesting beaches near the equator to seasonal foraging grounds as far north as Canada. The ability of leatherbacks to maintain core body temperature (Tb) higher than that of the surrounding water is thought to be a key element of their biology that permits them to exploit productive waters at high latitudes. We provide the first recordings of Tb from freely swimming leatherbacks at a northern foraging ground, and use these data to assess the importance of behavioral adjustments and metabolic sources of heat for maintenance of the thermal gradient (Tg). The mean Tb for individual leatherbacks ranged from 25.4 ± 1.7 to 27.3 ± 0.3 °C, and Tg ranged from 10.7 ± 2.4 to 12.1 ± 1.7 °C. Variation in mean Tb was best explained by the amount of time that turtles spent in the relatively warm surface waters. A diel trend in Tb was apparent, with daytime cooling suggestive of prey ingestion and night-time warming attributable to endogenous heat production. We estimate that metabolic rates necessary to support the observed Tg are ~3 times higher than resting metabolic rate, and that specific dynamic action is an important source of heat for foraging leatherbacks. © 2014. Published by The Company of Biologists Ltd.

  20. Diode probes for spatiotemporal optical control of multiple neurons in freely moving animals

    Science.gov (United States)

    Koos, Tibor; Buzsáki, György

    2012-01-01

    Neuronal control with high temporal precision is possible with optogenetics, yet currently available methods do not enable to control independently multiple locations in the brains of freely moving animals. Here, we describe a diode-probe system that allows real-time and location-specific control of neuronal activity at multiple sites. Manipulation of neuronal activity in arbitrary spatiotemporal patterns is achieved by means of an optoelectronic array, manufactured by attaching multiple diode-fiber assemblies to high-density silicon probes or wire tetrodes and implanted into the brains of animals that are expressing light-responsive opsins. Each diode can be controlled separately, allowing localized light stimulation of neuronal activators and silencers in any temporal configuration and concurrent recording of the stimulated neurons. Because the only connections to the animals are via a highly flexible wire cable, unimpeded behavior is allowed for circuit monitoring and multisite perturbations in the intact brain. The capacity of the system to generate unique neural activity patterns facilitates multisite manipulation of neural circuits in a closed-loop manner and opens the door to addressing novel questions. PMID:22496529

  1. Direct measurement of the ballistic motion of a freely floating colloid in Newtonian and viscoelastic fluids

    Science.gov (United States)

    Hammond, Andrew P.; Corwin, Eric I.

    2017-10-01

    A thermal colloid suspended in a liquid will transition from a short-time ballistic motion to a long-time diffusive motion. However, the transition between ballistic and diffusive motion is highly dependent on the properties and structure of the particular liquid. We directly observe a free floating tracer particle's ballistic motion and its transition to the long-time regime in both a Newtonian fluid and a viscoelastic Maxwell fluid. We examine the motion of the free particle in a Newtonian fluid and demonstrate a high degree of agreement with the accepted Clercx-Schram model for motion in a dense fluid. Measurements of the functional form of the ballistic-to-diffusive transition provide direct measurements of the temperature, viscosity, and tracer radius. We likewise measure the motion in a viscoelastic Maxwell fluid and find a significant disagreement between the theoretical asymptotic behavior and our measured values of the microscopic properties of the fluid. We observe a greatly increased effective mass for a freely moving particle and a decreased plateau modulus.

  2. A wireless power transmission system for implantable devices in freely moving rodents.

    Science.gov (United States)

    Eom, Kyungsik; Jeong, Joonsoo; Lee, Tae Hyung; Kim, Jinhyung; Kim, Junghoon; Lee, Sung Eun; Kim, Sung June

    2014-08-01

    Reliable wireless power delivery for implantable devices in animals is highly desired for safe and effective experimental use. Batteries require frequent replacement; wired connections are inconvenient and unsafe, and short-distance inductive coupling requires the attachment of an exterior transmitter to the animal's body. In this article, we propose a solution by which animals with implantable devices can move freely without attachments. Power is transmitted using coils attached to the animal's cage and is received by a receiver coil implanted in the animal. For a three-dimensionally uniform delivery of power, we designed a columnar dual-transmitter coil configuration. A resonator-based inductive link was adopted for efficient long-range power delivery, and we used a novel biocompatible liquid crystal polymer substrate as the implantable receiver device. Using this wireless power delivery system, we obtain an average power transfer efficiency of 15.2% (minimum efficiency of 10% and a standard deviation of 2.6) within a cage of 15×20×15 cm3.

  3. Estimation of unsteady aerodynamics in the wake of a freely flying European starling (Sturnus vulgaris.

    Directory of Open Access Journals (Sweden)

    Hadar Ben-Gida

    Full Text Available Wing flapping is one of the most widespread propulsion methods found in nature; however, the current understanding of the aerodynamics in bird wakes is incomplete. The role of the unsteady motion in the flow and its contribution to the aerodynamics is still an open question. In the current study, the wake of a freely flying European starling has been investigated using long-duration high-speed Particle Image Velocimetry (PIV in the near wake. Kinematic analysis of the wings and body of the bird has been performed using additional high-speed cameras that recorded the bird movement simultaneously with the PIV measurements. The wake evolution of four complete wingbeats has been characterized through reconstruction of the time-resolved data, and the aerodynamics in the wake have been analyzed in terms of the streamwise forces acting on the bird. The profile drag from classical aerodynamics was found to be positive during most of the wingbeat cycle, yet kinematic images show that the bird does not decelerate. It is shown that unsteady aerodynamics are necessary to satisfy the drag/thrust balance by approximating the unsteady drag term. These findings may shed light on the flight efficiency of birds by providing a partial answer to how they minimize drag during flapping flight.

  4. Dynamics of spontaneous local field potentials in the anterior claustrum of freely moving rats.

    Science.gov (United States)

    Jankowski, Maciej M; Islam, Md Nurul; O'Mara, Shane M

    2017-12-15

    The functions of the claustrum are not well understood. Few studies explore its electrophysiological properties in awake animals. Here, we address this lacuna by recording spontaneous local field potential (LFP) activity in the anterior claustrum of rats freely exploring open field environments under differing conditions (light; dark; with, without an object present). We found three peaks in the LFP power spectral density (PSD) at 1-4Hz, 4-7Hz and 8-12Hz. Two of those peaks, in the 1-4Hz and 8-12Hz bands, were present in almost all recordings and dominated the power spectrum. The power or frequency of detected peaks in some cases changed depending on the environmental context. The power of detected frequency bands of spontaneous LFPs showed varied patterns of distribution across the experimental arena. The 8-12Hz band was predominantly found at running speeds of up to 6cm/s. We suggest that spontaneous LFP activity in the anterior claustrum depends on the environmental context and running speed of the animal. Copyright © 2017. Published by Elsevier B.V.

  5. Flexible Coupling of Respiration and Vocalizations with Locomotion and Head Movements in the Freely Behaving Rat

    Directory of Open Access Journals (Sweden)

    Joseph Andrews Alves

    2016-01-01

    Full Text Available Quadrupedal mammals typically synchronize their respiration with body movements during rhythmic locomotion. In the rat, fast respiration is coupled to head movements during sniffing behavior, but whether respiration is entrained by stride dynamics is not known. We recorded intranasal pressure, head acceleration, instantaneous speed, and ultrasonic vocalizations from male and female adult rats while freely behaving in a social environment. We used high-speed video recordings of stride to understand how head acceleration signals relate to locomotion and developed techniques to identify episodes of sniffing, walking, trotting, and galloping from the recorded variables. Quantitative analysis of synchrony between respiration and head acceleration rhythms revealed that respiration and locomotion movements were coordinated but with a weaker coupling than expected from previous work in other mammals. We have recently shown that rats behaving in social settings produce high rates of ultrasonic vocalizations during locomotion bouts. Accordingly, rats emitted vocalizations in over half of the respiratory cycles during fast displacements. We present evidence suggesting that emission of these calls disrupts the entrainment of respiration by stride. The coupling between these two variables is thus flexible, such that it can be overridden by other behavioral demands.

  6. Effect of cascade remnants on freely migrating defects in Cu-1% Au alloys

    Energy Technology Data Exchange (ETDEWEB)

    Iwase, A.; Rehn, L.E.; Baldo, P.M.; Funk, L. [Argonne National Lab., IL (United States). Materials Science Div.

    1997-03-01

    The effects of cascade remnants on Freely Migrating Defects (FMD) were studied by measuring Radiation-Induced Segregation (RIS) in Cu-1%Au at 400degC during simultaneous irradiation with 1.5-MeV He and (400-800)-keV heavy ions (Ne, Ar or Cu). The large RIS observed during 1.5-MeV He-only irradiation was dramatically suppressed under simultaneous heavy ion irradiation. For Cu simultaneous irradiation, the suppression disappeared immediately after the Cu irradiation ceased, while for simultaneous inert gas (Ne or Ar) irradiation, the suppression persisted after the ion beam was turned off. These results demonstrate that the displacement cascades created by heavy ions introduce additional annihilation sites, which reduce the steady-state FMD concentrations. As the cascade remnants produced by Cu ions are thermally unstable at 400degC, the RIS suppression occurs only during simultaneous irradiation. On the other hand, the inert gas atoms which accumulate in the specimen apparently stabilize the cascade remnants, allowing the suppression to persist. (author)

  7. Experimental study of forces on freely moving spherical particles during resuspension into turbulent flow

    CERN Document Server

    Traugott, Hadar

    2015-01-01

    Turbulent resuspension is the process of lifting solid particles from the bottom by turbulent flow, ubiquitous in natural and industrial problems. The process is a sequence of events that start with an incipient motion when the particle is dislodged from its place, continue as sliding or rolling along the surface, and ending with the detachment of the particle from the surface and lifting it up into the flow. In this study we measure in details the motion of freely moving solid spherical particles along the bottom smooth wall under an oscillating grid turbulence and track them through the lift-off events. We measure simultaneously the Lagrangian trajectories of the particles and the flow tracers around them. We estimate the local flow parameters and extract the different force terms that act on a particle. For the particles of the diameter comparable with the Kolmogorov length scale, either sliding or rolling along the smooth wall under a zero-mean turbulent flow, we find that: i) the lift force is a dominant...

  8. Spike count, spike timing and temporal information in the cortex of awake, freely moving rats

    Science.gov (United States)

    Scaglione, Alessandro; Foffani, Guglielmo; Moxon, Karen A.

    2014-08-01

    Objective. Sensory processing of peripheral information is not stationary but is, in general, a dynamic process related to the behavioral state of the animal. Yet the link between the state of the behavior and the encoding properties of neurons is unclear. This report investigates the impact of the behavioral state on the encoding mechanisms used by cortical neurons for both detection and discrimination of somatosensory stimuli in awake, freely moving, rats. Approach. Neuronal activity was recorded from the primary somatosensory cortex of five rats under two different behavioral states (quiet versus whisking) while electrical stimulation of increasing stimulus strength was delivered to the mystacial pad. Information theoretical measures were then used to measure the contribution of different encoding mechanisms to the information carried by neurons in response to the whisker stimulation. Main results. We found that the behavioral state of the animal modulated the total amount of information conveyed by neurons and that the timing of individual spikes increased the information compared to the total count of spikes alone. However, the temporal information, i.e. information exclusively related to when the spikes occur, was not modulated by behavioral state. Significance. We conclude that information about somatosensory stimuli is modulated by the behavior of the animal and this modulation is mainly expressed in the spike count while the temporal information is more robust to changes in behavioral state.

  9. Spatial and temporal variation of freely dissolved PAHs in an urban river undergoing Superfund remediation

    Science.gov (United States)

    Sower, GJ; Anderson, K.A.

    2014-01-01

    Urban rivers with a history of industrial use can exhibit spatial and temporal variations in contaminant concentrations that may significantly affect risk evaluations and even the assessment of remediation efforts. Concentrations of 15 biologically available priority pollutant polycyclic aromatic hydrocarbons (PAHs) were measured over five years along 18.5 miles of the lower Willamette River using passive sampling devices and HPLC. The study area includes the Portland Harbor Superfund megasite with several PAH sources including remediation operations for coal tar at RM 6.3 west and an additional Superfund site, McCormick and Baxter, at RM 7 east consisting largely of creosote contamination. Study results show that organoclay capping at the McCormick and Baxter Superfund Site reduced PAHs from a pre-cap average of 440 ± 422 ng/L to 8 ± 3 ng/L post-capping. Results also reveal that dredging of submerged coal tar nearly tripled nearby freely dissolved PAH concentrations. For apportioning sources, fluoranthene/ pyrene and phenanthrene/anthracene diagnostic ratios from passive sampling devices were established for creosote and coal tar contamination and compared to published sediment values. PMID:19174872

  10. An implantable device for neuropsychiatric rehabilitation by chronic deep brain stimulation in freely moving rats.

    Science.gov (United States)

    Liu, Hongyu; Wang, Chenguang; Zhang, Fuqiang; Jia, Hong

    2017-02-08

    Successful practice of clinical deep brain stimulation (DBS) calls for basic research on the mechanisms and explorations of new indications in animals. In the article, a new implantable, single-channel, low-power miniature device is proposed, which may transmit pulses chronically into the brain nucleus of freely moving rats. The DBS system consists of an implantable pulse generator (IPG), a bipolar electrode, and an external programmer. The IPG circuit module is assembled as a 20-mm diameter circular board and fixed on a rat's skull together with an electrode and battery. The rigid electrode may make its fabrication and implantation more easy. The external programmer is designed for bidirectional communication with the IPG by a telecontrol transceiver and adjusts stimulation parameters. A biological validation was performed in which the effects of electrical stimulation in brain nucleus accumbens were detected. The programmed parameters were accurate, implant steady, and power sufficient to allow stimulation for more than 3 months. The larger area of the electrode tip provided a moderate current or charge density and minimized the damage from electrochemistry and pyroelectricity. The rats implanted with the device showed a reduction in morphine-induced conditioned place preference after high-frequency stimulation. In conclusion, the DBS device is based on the criteria of simple technology, minimal invasion, low cost, small in size, light-weight, and wireless controlled. This shows that our DBS device is appropriate and can be used for preclinical studies, indicating its potential utility in the therapy and rehabilitation of neuropsychiatric disorders.

  11. Electric field control of a fluid transfer between freely suspended and sessile droplets

    Science.gov (United States)

    Choi, Suhwan; Saveliev, Alexei

    2015-11-01

    This works explore direct fluid transfer between microdroplets using liquid bridges stabilized by ac electric field. Experiments are performed with freely and sessile microdroplets of pure glycerol and water with dye. The droplets are placed along electric field directions in a cell with parallel plate electrodes filled with silicone oil. The electrical conductivity of droplets is changed from 1 to 200 μS/cm by adding dye solutions. Liquid bridges interconnecting two microdroplets can be created using an alternating electric field from 0.3 to 0.7 kV/mm with a frequency of 10.3 kHz. For such bridging fluid can be transferred through the liquid bridge from one droplet to another due to the pressure difference. The process is recorded using a CCD camera. The fluid flowrates in the range from ~ 100 to 10 nL/s are recorded with different electric fields and liquid conductivity. We propose that the manipulation of the liquid bridge will be the method in which small fluid volumes are dispensed.

  12. Whole-brain calcium imaging with cellular resolution in freely behaving Caenorhabditis elegans

    Science.gov (United States)

    Nguyen, Jeffrey; Shipley, Frederick; Linder, Ashley; Plummer, George; Liu, Mochi; Setru, Sagar; Shaevitz, Joshua; Leifer, Andrew

    The ability to acquire large-scale recordings of neuronal activity in awake and unrestrained animals is needed to provide new insights into how populations of neurons generate animal behavior. Acquiring this data, however, is challenging because it is difficult to track and image individual neurons as an animal deforms its posture and moves many body lengths. Here, we present an instrument capable of recording intracellular calcium transients from the majority of neurons in the head of a freely behaving Caenorhabditis elegans with cellular resolution while simultaneously recording the animal's position, posture, and locomotion. 3D volumetric fluorescent images of neurons expressing the calcium indicator GCaMP6s are recorded at 6 head-volumes/s using spinning disk confocal microscopy. At the same time, we record low magnification images of the animal to measure the animals behavior and track its head as it moves. We develop a time independent neuronal matching algorithm that uses non-rigid point set registration and machine learning to correctly match neurons across time. Using this method, we are able to observe calcium transients from up to 90 neurons for over 4 min and correlate the neural activity with the animal's behavior.

  13. Investigation of the freely available easy-to-use software 'EZR' for medical statistics.

    Science.gov (United States)

    Kanda, Y

    2013-03-01

    Although there are many commercially available statistical software packages, only a few implement a competing risk analysis or a proportional hazards regression model with time-dependent covariates, which are necessary in studies on hematopoietic SCT. In addition, most packages are not clinician friendly, as they require that commands be written based on statistical languages. This report describes the statistical software 'EZR' (Easy R), which is based on R and R commander. EZR enables the application of statistical functions that are frequently used in clinical studies, such as survival analyses, including competing risk analyses and the use of time-dependent covariates, receiver operating characteristics analyses, meta-analyses, sample size calculation and so on, by point-and-click access. EZR is freely available on our website (http://www.jichi.ac.jp/saitama-sct/SaitamaHP.files/statmed.html) and runs on both Windows (Microsoft Corporation, USA) and Mac OS X (Apple, USA). This report provides instructions for the installation and operation of EZR.

  14. Estimation of unsteady aerodynamics in the wake of a freely flying European starling

    CERN Document Server

    Ben-Gida, Hadar; Taylor, Zachary J; Bezner-Kerr, Wayne; Guglielmo, Christopher G; Kopp, Gregory A; Gurka, Roi

    2013-01-01

    Wing flapping is one of the most widespread propulsion methods found in nature; however, the current understanding of the aerodynamics in bird wakes is incomplete. The role of the unsteady motion in the flow and its contribution to the aerodynamics is still an open question. In the current study, the wake of a freely flying European starling has been investigated using long-duration high-speed Particle Image Velocimetry (PIV) in the near wake. Kinematic analysis of the wings and body of the bird has been performed using additional high-speed cameras that recorded the bird movement simultaneously with the PIV measurements. The wake evolution of four complete wingbeats has been characterized through reconstruction of the time resolved data, and the aerodynamics in the wake have been analyzed in terms of the streamwise forces acting on the bird. The profile drag from classical aerodynamics was found to be positive during most of the wingbeat cycle, yet kinematic images show that the bird does not decelerate. It ...

  15. Real-time submillisecond single-molecule FRET dynamics of freely diffusing molecules with liposome tethering

    Science.gov (United States)

    Kim, Jae-Yeol; Kim, Cheolhee; Lee, Nam Ki

    2015-04-01

    Single-molecule fluorescence resonance energy transfer (smFRET) is one of the powerful techniques for deciphering the dynamics of unsynchronized biomolecules. However, smFRET is limited in its temporal resolution for observing dynamics. Here, we report a novel method for observing real-time dynamics with submillisecond resolution by tethering molecules to freely diffusing 100-nm-sized liposomes. The observation time for a diffusing molecule is extended to 100 ms with a submillisecond resolution, which allows for direct analysis of the transition states from the FRET time trace using hidden Markov modelling. We measure transition rates of up to 1,500 s-1 between two conformers of a Holliday junction. The rapid diffusional migration of Deinococcus radiodurans single-stranded DNA-binding protein (SSB) on single-stranded DNA is resolved by FRET, faster than that of Escherichia coli SSB by an order of magnitude. Our approach is a powerful method for studying the dynamics and movements of biomolecules at submillisecond resolution.

  16. Estimation of unsteady aerodynamics in the wake of a freely flying European starling (Sturnus vulgaris).

    Science.gov (United States)

    Ben-Gida, Hadar; Kirchhefer, Adam; Taylor, Zachary J; Bezner-Kerr, Wayne; Guglielmo, Christopher G; Kopp, Gregory A; Gurka, Roi

    2013-01-01

    Wing flapping is one of the most widespread propulsion methods found in nature; however, the current understanding of the aerodynamics in bird wakes is incomplete. The role of the unsteady motion in the flow and its contribution to the aerodynamics is still an open question. In the current study, the wake of a freely flying European starling has been investigated using long-duration high-speed Particle Image Velocimetry (PIV) in the near wake. Kinematic analysis of the wings and body of the bird has been performed using additional high-speed cameras that recorded the bird movement simultaneously with the PIV measurements. The wake evolution of four complete wingbeats has been characterized through reconstruction of the time-resolved data, and the aerodynamics in the wake have been analyzed in terms of the streamwise forces acting on the bird. The profile drag from classical aerodynamics was found to be positive during most of the wingbeat cycle, yet kinematic images show that the bird does not decelerate. It is shown that unsteady aerodynamics are necessary to satisfy the drag/thrust balance by approximating the unsteady drag term. These findings may shed light on the flight efficiency of birds by providing a partial answer to how they minimize drag during flapping flight.

  17. Corrosion Behavior of Cast Iron in Freely Aerated Stagnant Arabian Gulf Seawater

    Science.gov (United States)

    Sherif, El-Sayed M.; Abdo, Hany S.; Almajid, Abdulhakim A.

    2015-01-01

    In this work, the results obtained from studying the corrosion of cast iron in freely aerated stagnant Arabian Gulf seawater (AGS) at room temperature were reported. The study was carried out using weight-loss (WL), cyclic potentiodynamic polarization (CPP), open-circuit potential (OCP), and electrochemical impedance spectroscopy (EIS) measurements and complemented by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) investigations. WL experiments between two and 10 days’ immersion in the test electrolyte indicated that the weight-loss the cast iron increases with increasing the time of immersion. CPP measurements after 1 h and 24 h exposure period showed that the increase of time decreases the corrosion via decreasing the anodic and cathodic currents, as well as decreasing the corrosion current and corrosion rate and increasing the polarization resistance of the cast iron. EIS data confirmed the ones obtained by WL and CPP that the increase of immersion time decreases the corrosion of cast iron by increasing its polarization resistance.

  18. Estimation of traversed distance in level walking using a single inertial measurement unit attached to the waist.

    Science.gov (United States)

    Kose, Alper; Cereatti, Andrea; Della Croce, Ugo

    2011-01-01

    A method for estimating step length during level walking using a single inertial measurement unit is proposed. A combination of an optimally filtered direct and reverse integration technique and a velocity update technique for the initial velocity values identification was implemented to reduce the effects of the acceleration signals drift. The method takes advantage of the cyclic nature of gait. The inertial measurement unit was placed at waist level on the right side and the method was validated on eight subjects walking for 75 m while varying their speed. The traversed distance was estimated with an average error equal to 0.8% of the total walking distance.

  19. TRPV-1-mediated elimination of residual iPS cells in bioengineered cardiac cell sheet tissues

    Science.gov (United States)

    Matsuura, Katsuhisa; Seta, Hiroyoshi; Haraguchi, Yuji; Alsayegh, Khaled; Sekine, Hidekazu; Shimizu, Tatsuya; Hagiwara, Nobuhisa; Yamazaki, Kenji; Okano, Teruo

    2016-01-01

    The development of a suitable strategy for eliminating remaining undifferentiated cells is indispensable for the use of human-induced pluripotent stem (iPS) cell-derived cells in regenerative medicine. Here, we show for the first time that TRPV-1 activation through transient culture at 42 °C in combination with agonists is a simple and useful strategy to eliminate iPS cells from bioengineered cardiac cell sheet tissues. When human iPS cells were cultured at 42 °C, almost all cells disappeared by 48 hours through apoptosis. However, iPS cell-derived cardiomyocytes and fibroblasts maintained transcriptional and protein expression levels, and cardiac cell sheets were fabricated after reducing the temperature. TRPV-1 expression in iPS cells was upregulated at 42 °C, and iPS cell death at 42 °C was TRPV-1-dependent. Furthermore, TRPV-1 activation through thermal or agonist treatment eliminated iPS cells in cardiac tissues for a final concentration of 0.4% iPS cell contamination. These findings suggest that the difference in tolerance to TRPV-1 activation between iPS cells and iPS cell-derived cardiac cells could be exploited to eliminate remaining iPS cells in bioengineered cell sheet tissues, which will further reduce the risk of tumour formation. PMID:26888607

  20. TRPV-1-mediated elimination of residual iPS cells in bioengineered cardiac cell sheet tissues.

    Science.gov (United States)

    Matsuura, Katsuhisa; Seta, Hiroyoshi; Haraguchi, Yuji; Alsayegh, Khaled; Sekine, Hidekazu; Shimizu, Tatsuya; Hagiwara, Nobuhisa; Yamazaki, Kenji; Okano, Teruo

    2016-02-18

    The development of a suitable strategy for eliminating remaining undifferentiated cells is indispensable for the use of human-induced pluripotent stem (iPS) cell-derived cells in regenerative medicine. Here, we show for the first time that TRPV-1 activation through transient culture at 42 °C in combination with agonists is a simple and useful strategy to eliminate iPS cells from bioengineered cardiac cell sheet tissues. When human iPS cells were cultured at 42 °C, almost all cells disappeared by 48 hours through apoptosis. However, iPS cell-derived cardiomyocytes and fibroblasts maintained transcriptional and protein expression levels, and cardiac cell sheets were fabricated after reducing the temperature. TRPV-1 expression in iPS cells was upregulated at 42 °C, and iPS cell death at 42 °C was TRPV-1-dependent. Furthermore, TRPV-1 activation through thermal or agonist treatment eliminated iPS cells in cardiac tissues for a final concentration of 0.4% iPS cell contamination. These findings suggest that the difference in tolerance to TRPV-1 activation between iPS cells and iPS cell-derived cardiac cells could be exploited to eliminate remaining iPS cells in bioengineered cell sheet tissues, which will further reduce the risk of tumour formation.

  1. [Induced pluripotent stem (iPS) cell - issues for clinical application - ].

    Science.gov (United States)

    Aoi, Takashi

    2013-01-01

    Induced pluripotent stem (iPS) cells are generated from somatic cells by introducing small sets of transcription factors. iPS cells demonstrate pluripotency and the ability to self-renew. In addition, iPS cells can be generated from donor individuals with particular characteristics. Based on these features, iPS cells are expected to be applicable in drug discovery, the study of disease mechanisms and cell therapy. From a technical point of view, "diversity" is the key word. At present, iPS cells can be derived using various techniques, resulting in diversity in the quality of iPS cells generated. Therefore, optimization of the derivation technology is one of the most important issues. Another "diversity" is in the propensities amongst iPS cell lines derived using similar techniques. Thus, strategies for selecting good quality lines remain to be established. Considering such technical hurdles, establishment of an iPS cell bank consisting of high quality and versatile iPS lines is a promising idea because of the merits of cost and quality control. Now, we are exploring relevant parameters for the quality control of banked cells. The challenges facing clinical application of iPS cells are new but not unprecedented. To realize clinical applications of iPS cells, we need to make these challenges clear and overcome them through partnership not only with industry, governments and universities, but also patients and society at large.

  2. Methods for iPS cell generation for basic research and clinical applications.

    Science.gov (United States)

    Mochiduki, Yuji; Okita, Keisuke

    2012-06-01

    The induction of pluripotency can be achieved by forced expression of defined factors in somatic cells. The established cells, termed induced pluripotent stem (iPS) cells, have pluripotency and an infinite capacity for self-renewal in common with embryonic stem (ES) cells. Patient-specific iPS cells could be a useful source for drug discovery and cell transplantation therapies; however, the original method for iPS cell generation had several issues that were obstacles to their clinical application. Recent studies have brought about various improvements for iPS cell generation and uncovered several characteristics of iPS cells. Here we summarize the current status of iPS cell studies, with a focus on the improved methods that can be used to generate iPS cells, and also refer to the future challenges. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Properties of Extruded PS-212 Type Self-Lubricating Materials

    Science.gov (United States)

    Waters, W. J.; Sliney, H. E.; Soltis, R. F.

    1993-01-01

    Research has been underway at the NASA Lewis Research Center since the 1960's to develop high temperature, self-lubricating materials. The bulk of the research has been done in-house by a team of researchers from the Materials Division. A series of self-lubricating solid material systems has been developed over the years. One of the most promising is the composite material system referred to as PS-212 or PM-212. This material is a powder metallurgy product composed of metal bonded chromium carbide and two solid lubricating materials known to be self-lubricating over a wide temperature range. NASA feels this material has a wide potential in industrial applications. Simplified processing of this material would enhance its commercial potential. Processing changes have the potential to reduce processing costs, but tribological and physical properties must not be adversely affected. Extrusion processing has been employed in this investigation as a consolidation process for PM-212/PS-212. It has been successful in that high density bars of EX-212 (extruded PM-212) can readily be fabricated. Friction and strength data indicate these properties have been maintained or improved over the P.M. version. A range of extrusion temperatures have been investigated and tensile, friction, wear, and microstructural data have been obtained. Results indicate extrusion temperatures are not critical from a densification standpoint, but other properties are temperature dependent.

  4. Phase morphological study on SEBS compatibilized PS/LDPE blends

    Directory of Open Access Journals (Sweden)

    Chatchai Kunyawut

    2014-09-01

    Full Text Available The co-continuous phase morphology of polystyrene (PS/low density polyethylene (LDPE blends compatibilized with poly(styrene-block-ethylene/butylene-block-styrene triblock copolymers (SEBS with varying molecular weights has been investigated. The blend samples were prepared in a mini-twin screw extruder. The barrel length and diameter are 224 and 16 mm, respectively. The diameter of the capillary die is 1 mm. The concentration of the blends was 70/30 wt% of PS/LDPE while that of the SEBS used was 5 wt% of the blend. The mixing temperatures used were 180, 250, and 280o C, and a screw speed of 60 rpm. The morphology of the blends was investigated using an AFM technique. Average droplet diameters of the blend samples were determined using an OM technique. The co-continuous morphology has not been obtained in all the blends, although the mixing temperature used is as high as 280o C. The experimental results indicated that the model prediction of the co-continuous morphology proposed by Willemse and co-worker was not applicable to the blend systems studied. Only droplet-type dispersion was observed. This is considered to arise from the processing conditions and the mixing device used. The blend compatibilized with the high molecular weight SEBS had higher dispersed phase size than that of the blend compatibilized with the medium and low molecular weight SEBSs. This behaviour is likely to arise from coalescence during melt processing.

  5. Preparations for Upgrading the RF Systems of the PS Booster

    CERN Document Server

    Albright, Simon; Shaposhnikova, Elena

    2016-01-01

    The accelerators of the LHC injector chain need to be upgraded to provide the HL-LHC beams. The PS Booster, the first synchrotron in the LHC injection chain, uses three different RF systems (first, second and up to tenth harmonic) in each of its four rings. As part of the LHC Injector Upgrade the current ferrite RF systems will be replaced with broadband Finemet cavities, increasing the flexibility of the RF system. A Finemet test cavity has been installed in Ring 4 to investigate its effect on machine performance, especially beam stability, during extensive experimental studies. Due to large space charge impedance Landau damping is lost through most of the cycle in single harmonic operation, but is recovered when using the second harmonic and controlled longitudinal emittance blow-up. This paper compares beam parameters during acceleration with and without the Finemet test cavity. Comparisons were made using beam measurements and simulations with the BLonD code based on a full PS Booster impedance model. Thi...

  6. KSR-based medium improves the generation of high-quality mouse iPS cells.

    Science.gov (United States)

    Liu, Kai; Wang, Fang; Ye, Xiaoying; Wang, Lingling; Yang, Jiao; Zhang, Jingzhuo; Liu, Lin

    2014-01-01

    Induced pluripotent stem (iPS) cells from somatic cells have great potential for regenerative medicine. The efficiency in generation of iPS cells has been significantly improved in recent years. However, the generation of high-quality iPS cells remains of high interest. Consistently, we demonstrate that knockout serum replacement (KSR)-based medium accelerates iPS cell induction and improves the quality of iPS cells, as confirmed by generation of chimeras and all iPS cell-derived offspring with germline transmission competency. Both alkaline phosphatase (AP) activity assay and expression of Nanog have been used to evaluate the efficiency of iPS cell induction and formation of ES/iPS cell colonies; however, appropriate expression of Nanog frequently indicates the quality of ES/iPS cells. Interestingly, whereas foetal bovine serum (FBS)-based media increase iPS cell colony formation, as revealed by AP activity, KSR-based media increase the frequency of iPS cell colony formation with Nanog expression. Furthermore, inhibition of MAPK/ERK by a specific inhibitor, PD0325901, in KSR- but not in FBS-based media significantly increases Nanog-GFP+ iPS cells. In contrast, addition of bFGF in KSR-based media decreases proportion of Nanog-GFP+ iPS cells. Remarkably, PD can rescue Nanog-GFP+ deficiency caused by bFGF. These data suggest that MAPK/ERK pathway influences high quality mouse iPS cells and that KSR- and PD-based media could enrich homogeneous authentic pluripotent stem cells.

  7. Analyzing freely dissolved concentrations of cationic surfactant utilizing ion-exchange capability of polyacrylate coated solid-phase microextraction fibers

    NARCIS (Netherlands)

    Chen, Y.|info:eu-repo/dai/nl/322994179; Droge, S.T.J.|info:eu-repo/dai/nl/304834017; Hermens, J.L.M.|info:eu-repo/dai/nl/069681384

    2012-01-01

    A 7-μm polyacrylate (PA) coated fiber was successfully employed to determine freely dissolved concentrations of cationic surfactants by solid-phase microextraction (SPME) and utilizing the capability of the PA-coating to sorb organic cations via ion-exchange at carboxylic groups. Measured

  8. Firing properties of dopamine neurons in freely moving dopamine-deficient mice: Effects of dopamine receptor activation and anesthesia

    OpenAIRE

    Robinson, Siobhan; Smith, David M.; Mizumori, Sheri J. Y.; Palmiter, Richard D.

    2004-01-01

    To examine the regulation of midbrain dopamine neurons, recordings were obtained from single neurons of freely moving, genetically engineered dopamine-deficient (DD) mice. DD mice were tested without dopamine signaling (basal state) and with endogenous dopamine signaling (after L-dopa administration). In the basal state, when dopamine concentration in DD mice is

  9. Strong activation of vascular prejunctional beta 2-adrenoceptors in freely moving rats by adrenaline released as a co-transmitter

    NARCIS (Netherlands)

    COPPES, RP; SMIT, J; KHALI, NN; Brouwer, F.; ZAAGSMA, J

    1993-01-01

    The effect of adrenaline on the electrically evoked noradrenaline overflow in the portal vein of adrenal demedullated freely moving rats was studied. Adrenaline (100 ng/min) was infused for 2 h into the portal vein. After a 1-h interval when plasma adrenaline had returned to pre-infusion

  10. Nutritional requirements for methyl orange decolourisation by freely suspended cells and growing cells of Lactobacillus casei TISTR 1500

    Directory of Open Access Journals (Sweden)

    Phisit Seesuriyachan

    2011-01-01

    Full Text Available Lactobacillus casei TISTR 1500 possesses cytoplasmic azoreductase and can breakdown azo bonds under microaerophilic condition. It was found previously that a growing culture is more tolerant to a high initial dye concentration than freely suspended cells supplied only with sucrose. The present study is aimed at investigating the nutritive requirements for decolourisation by the growing cells and the freely suspended cells using Plackett-Burmann experimental design. In this study, the composition of the medium was found to play an important role in methyl orange decolourisation and biomass production. Sucrose, meat extract and peptone increased methyl orange decolourisation by freely suspended cells, whereas sodium acetate exerted a negative effect on decolourisation. In addition, it was observed that the yeast and meat extracts enhanced the degradation of the dye by the growing cells. Sucrose was an important factor in biomass production by freely suspended cells and growing cells. On the other hand, dipotassium hydrogen phosphate and sodium acetate decreased the biomass production. These findings promote the understanding and knowledge about the requirements of azo dye decolourisation by Lactobacillus casei.

  11. Estimation of activity related energy expenditure and resting metabolic rate in freely moving mice from indirect calorimetry data

    NARCIS (Netherlands)

    Klinken, J.B. van; Berg, S.A.A. van den; Havekes, L.M.; Willems Van Dijk, K.

    2012-01-01

    Physical activity (PA) is a main determinant of total energy expenditure (TEE) and has been suggested to play a key role in body weight regulation. However, thus far it has been challenging to determine what part of the expended energy is due to activity in freely moving subjects. We developed a

  12. MicroRNA expression profiles of human iPS cells, retinal pigment epithelium derived from iPS, and fetal retinal pigment epithelium.

    Science.gov (United States)

    Greene, Whitney A; Muñiz, Alberto; Plamper, Mark L; Kaini, Ramesh R; Wang, Heuy-Ching

    2014-06-24

    The objective of this report is to describe the protocols for comparing the microRNA (miRNA) profiles of human induced-pluripotent stem (iPS) cells, retinal pigment epithelium (RPE) derived from human iPS cells (iPS-RPE), and fetal RPE. The protocols include collection of RNA for analysis by microarray, and the analysis of microarray data to identify miRNAs that are differentially expressed among three cell types. The methods for culture of iPS cells and fetal RPE are explained. The protocol used for differentiation of RPE from human iPS is also described. The RNA extraction technique we describe was selected to allow maximal recovery of very small RNA for use in a miRNA microarray. Finally, cellular pathway and network analysis of microarray data is explained. These techniques will facilitate the comparison of the miRNA profiles of three different cell types.

  13. Traversing field of view and AR-PIV for mid-field wake vortex investigation in a towing tank

    Science.gov (United States)

    Scarano, F.; van Wijk, C.; Veldhuis, L. L. M.

    2002-08-01

    Wake vortex flow experiments are performed in a water tank where a 1:48 scaled model of a large transport aircraft A340-300 is towed at the speed of 3 and 5 ms-1 with values of the angle of attack α={2°, 4°, 8°}. Particle image velocimetry (PIV) measurements are performed in a plane perpendicular to the towing direction describing the streamwise component of the wake vorticity. The instantaneous field of view (I-FOV) is traversed vertically with an underwater moving-camera device tracking the vortex core during the downward motion. An adaptive resolution (AR) image-processing technique is introduced that enhances the PIV interrogation in terms of spatial resolution and accuracy. The main objectives of the investigation are to demonstrate the applicability of PIV diagnostics in wake vortex research with towing-tank facilities. The specific implementation of the traversing field-of-view (T-FOV) technique and the AR image processing are driven by the need to characterize the vortex wake global properties as well as the vortex decay phenomenon in the mid- and far-field. Relevant aerodynamic information is obtained in the mid-field where the time evolution of the vortex structure (core radius and tangential velocity) and of the overall vortex wake (vortex trajectory, descent velocity, circulation) are discussed.

  14. Evaluation of freely available ancillary data used for detailed soil mapping in Brazil

    Science.gov (United States)

    Samuel-Rosa, Alessandro; Anjos, Lúcia; Vasques, Gustavo; Heuvelink, Gerard

    2014-05-01

    Brazil is one of the world's largest food producers, and is home of both largest rainforest and largest supply of renewable fresh water on Earth. However, it lacks detailed soil information in extensive areas of the country. The best soil map covering the entire country was published at a scale of 1:5,000,000. Termination of governmental support for systematic soil mapping in the 1980's made detailed soil mapping of the whole country a very difficult task to accomplish. Nowadays, due to new user-driven demands (e.g. precision agriculture), most detailed soil maps are produced for small size areas. Many of them rely on as is freely available ancillary data, although their accuracy is usually not reported or unknown. Results from a validation exercise that we performed using ground control points from a small hilly catchment (20 km²) in Southern Brazil (-53.7995ºE, -29.6355ºN) indicate that most freely available ancillary data needs some type of correction before use. Georeferenced and orthorectified RapidEye imagery (recently acquired by the Brazilian government) has a horizontal accuracy (root-mean-square error, RMSE) of 37 m, which is worse than the value published in the metadata (32 m). Like any remote sensing imagery, RapidEye imagery needs to be correctly registered before its use for soil mapping. Topographic maps produced by the Brazilian Army and derived geological maps (scale of 1:25,000) have a horizontal accuracy of 65 m, which is more than four times the maximum value allowed by Brazilian legislation (15 m). Worse results were found for geological maps derived from 1:50,000 topographic maps (RMSE = 147 m), for which the maximum allowed value is 30 m. In most cases positional errors are of systematic origin and can be easily corrected (e.g., affine transformation). ASTER GDEM has many holes and is very noisy, making it of little use in the studied area. TOPODATA, which is SRTM kriged from originally 3 to 1 arc-second by the Brazilian National

  15. Review of polyoxymethylene passive sampling methods for quantifying freely dissolved porewater concentrations of hydrophobic organic contaminants.

    Science.gov (United States)

    Arp, Hans Peter H; Hale, Sarah E; Elmquist Kruså, Marie; Cornelissen, Gerard; Grabanski, Carol B; Miller, David J; Hawthorne, Steven B

    2015-04-01

    Meth ods involving polyoxymethylene (POM) as a passive sampler are increasing in popularity to assess contaminant freely dissolved porewater concentrations in soils and sediments. These methods require contaminant-specific POM-water partition coefficients, KPOM . Certain methods for determining KPOM perform reproducibly (within 0.2 log units). However, other methods can give highly varying KPOM values (up to 2 log units), especially for polycyclic aromatic hydrocarbons (PAHs). To account for this variation, the authors tested the influence of key methodological components in KPOM determinations, including POM thickness, extraction procedures, and environmental temperature and salinity, as well as uptake kinetics in mixed and static systems. All inconsistencies in the peer-reviewed literature can be accounted for by the likelihood that thick POM materials (500 μm or thicker) do not achieve equilibrium (causing negative biases up to 1 log unit), or that certain POM extraction procedures do not ensure quantitative extraction (causing negative biases up to 2 log units). Temperature can also influence KPOM , although all previous literature studies were carried out at room temperature. The present study found that KPOM values at room temperature are independent (within 0.2 log units) of POM manufacture method, of thickness between 17 μm and 80 μm, and of salinity between 0% and 10%. Regarding kinetics, monochloro- to hexachloro-polychlorinated biphenyls (PCBs) were within 0.2 log units of equilibrium after 28 d in the mixed system, but only dichloro-PCBs achieved near equilibrium after 126 d in the static system. Based on these insights, recommended methods and KPOM values to facilitate interlaboratory reproducibility are presented. © 2015 SETAC.

  16. Identification of behaviour in freely moving dogs (Canis familiaris) using inertial sensors.

    Science.gov (United States)

    Gerencsér, Linda; Vásárhelyi, Gábor; Nagy, Máté; Vicsek, Tamas; Miklósi, Adam

    2013-01-01

    Monitoring and describing the physical movements and body postures of animals is one of the most fundamental tasks of ethology. The more precise the observations are the more sophisticated the interpretations can be about the biology of a certain individual or species. Animal-borne data loggers have recently contributed much to the collection of motion-data from individuals, however, the problem of translating these measurements to distinct behavioural categories to create an ethogram is not overcome yet. The objective of the present study was to develop a "behaviour tracker": a system composed of a multiple sensor data-logger device (with a tri-axial accelerometer and a tri-axial gyroscope) and a supervised learning algorithm as means of automated identification of the behaviour of freely moving dogs. We collected parallel sensor measurements and video recordings of each of our subjects (Belgian Malinois, N=12; Labrador Retrievers, N=12) that were guided through a predetermined series of standard activities. Seven behavioural categories (lay, sit, stand, walk, trot, gallop, canter) were pre-defined and each video recording was tagged accordingly. Evaluation of the measurements was performed by support vector machine (SVM) classification. During the analysis we used different combinations of independent measurements for training and validation (belonging to the same or different individuals or using different training data size) to determine the robustness of the application. We reached an overall accuracy of above 90% perfect identification of all the defined seven categories of behaviour when both training and validation data belonged to the same individual, and over 80% perfect recognition rate using a generalized training data set of multiple subjects. Our results indicate that the present method provides a good model for an easily applicable, fast, automatic behaviour classification system that can be trained with arbitrary motion patterns and potentially be

  17. Mismatch negativity (MMN in freely-moving rats with several experimental controls.

    Directory of Open Access Journals (Sweden)

    Lauren Harms

    Full Text Available Mismatch negativity (MMN is a scalp-recorded electrical potential that occurs in humans in response to an auditory stimulus that defies previously established patterns of regularity. MMN amplitude is reduced in people with schizophrenia. In this study, we aimed to develop a robust and replicable rat model of MMN, as a platform for a more thorough understanding of the neurobiology underlying MMN. One of the major concerns for animal models of MMN is whether the rodent brain is capable of producing a human-like MMN, which is not a consequence of neural adaptation to repetitive stimuli. We therefore tested several methods that have been used to control for adaptation and differential exogenous responses to stimuli within the oddball paradigm. Epidural electroencephalographic electrodes were surgically implanted over different cortical locations in adult rats. Encephalographic data were recorded using wireless telemetry while the freely-moving rats were presented with auditory oddball stimuli to assess mismatch responses. Three control sequences were utilized: the flip-flop control was used to control for differential responses to the physical characteristics of standards and deviants; the many standards control was used to control for differential adaptation, as was the cascade control. Both adaptation and adaptation-independent deviance detection were observed for high frequency (pitch, but not low frequency deviants. In addition, the many standards control method was found to be the optimal method for observing both adaptation effects and adaptation-independent mismatch responses in rats. Inconclusive results arose from the cascade control design as it is not yet clear whether rats can encode the complex pattern present in the control sequence. These data contribute to a growing body of evidence supporting the hypothesis that rat brain is indeed capable of exhibiting human-like MMN, and that the rat model is a viable platform for the further

  18. Simultaneous measurement of surface tension and viscosity using freely decaying oscillations of acoustically levitated droplets

    Science.gov (United States)

    Kremer, J.; Kilzer, A.; Petermann, M.

    2018-01-01

    Oscillations of small liquid drops around a spherical shape have been of great interest to scientists measuring physical properties such as interfacial tension and viscosity, over the last few decades. A powerful tool for contactless positioning is acoustic levitation, which has been used to simultaneously determine the surface tension and viscosity of liquids at ambient pressure. In order to extend this acoustic levitation measurement method to high pressure systems, the method is first evaluated under ambient pressure. To measure surface tension and viscosity using acoustically levitated oscillating drops, an image analysis method has to be developed and factors which may affect measurement, such as sound field or oscillation amplitude, have to be analyzed. In this paper, we describe the simultaneous measurement of surface tension and viscosity using freely decaying shape oscillations of acoustically levitated droplets of different liquids (silicone oils AK 5 and AK 10, squalane, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol) in air. These liquids vary in viscosity from 2 to about 30 mPa s. An acoustic levitation system, including an optimized standing wave acoustic levitator and a high-speed camera, was used for this study. An image analysis was performed with a self-written Matlab® code. The frequency of oscillation and the damping constant, required for the determination of surface tension and viscosity, respectively, were calculated from the evolution of the equatorial and polar radii. The results and observations are compared to data from the literature in order to analyze the accuracy of surface tension and viscosity determination, as well as the effect of non-spherical drop shape or amplitude of oscillation on measurement.

  19. Body appendages fine-tune posture and moments in freely manoeuvring fruit flies.

    Science.gov (United States)

    Berthé, Ruben; Lehmann, Fritz-Olaf

    2015-10-01

    The precise control of body posture by turning moments is key to elevated locomotor performance in flying animals. Although elevated moments for body stabilization are typically produced by wing aerodynamics, animals also steer using drag on body appendages, shifting their centre of body mass, and changing moments of inertia caused by active alterations in body shape. To estimate the instantaneous contribution of each of these components for posture control in an insect, we three-dimensionally reconstructed body posture and movements of body appendages in freely manoeuvring fruit flies (Drosophila melanogaster) by high-speed video and experimentally scored drag coefficients of legs and body trunk at low Reynolds number. The results show that the sum of leg- and abdomen-induced yaw moments dominates wing-induced moments during 17% of total flight time but is, on average, 7.2-times (roll, 3.4-times) smaller during manoeuvring. Our data reject a previous hypothesis on synergistic moment support, indicating that drag on body appendages and mass-shift inhibit rather than support turning moments produced by the wings. Numerical modelling further shows that hind leg extension alters the moments of inertia around the three main body axes of the animal by not more than 6% during manoeuvring, which is significantly less than previously reported for other insects. In sum, yaw, pitch and roll steering by body appendages probably fine-tune turning behaviour and body posture, without providing a significant advantage for posture stability and moment support. Motion control of appendages might thus be part of the insect's trimming reflexes, which reduce imbalances in moment generation caused by unilateral wing damage and abnormal asymmetries of the flight apparatus. © 2015. Published by The Company of Biologists Ltd.

  20. An Arbitrary Waveform Wearable Neuro-stimulator System for Neurophysiology Research on Freely Behaving Animals.

    Science.gov (United States)

    Samani, Mohsen Mosayebi; Mahnam, Amin; Hosseini, Nasrin

    2014-04-01

    Portable wireless neuro-stimulators have been developed to facilitate long-term cognitive and behavioral studies on the central nervous system in freely moving animals. These stimulators can provide precisely controllable input(s) to the nervous system, without distracting the animal attention with cables connected to its body. In this study, a low power backpack neuro-stimulator was developed for animal brain researches that can provides arbitrary stimulus waveforms for the stimulation, while it is small and light weight to be used for small animals including rats. The system consists of a controller that uses an RF link to program and activate a small and light microprocessor-based stimulator. A Howland current source was implemented to produce precise current controlled arbitrary waveform stimulations. The system was optimized for ultra-low power consumption and small size. The stimulator was first tested for its electrical specifications. Then its performance was evaluated in a rat experiment when electrical stimulation of medial longitudinal fasciculus induced circling behavior. The stimulator is capable of delivering programmed stimulations up to ± 2 mA with adjusting steps of 1 μA, accuracy of 0.7% and compliance of 6 V. The stimulator is 15 mm × 20 mm × 40 mm in size, weights 13.5 g without battery and consumes a total power of only 5.l mW. In the experiment, the rat could easily carry the stimulator and demonstrated the circling behavior for 0.1 ms current pulses of above 400 μA. The developed system has a competitive size and weight, whereas providing a wide range of operation and the flexibility of generating arbitrary stimulation patterns ideal for long-term experiments in the field of cognitive and neuroscience research.

  1. Effects of a ketogenic diet on hippocampal plasticity in freely moving juvenile rats.

    Science.gov (United States)

    Blaise, J Harry; Ruskin, David N; Koranda, Jessica L; Masino, Susan A

    2015-05-01

    Ketogenic diets are low-carbohydrate, sufficient protein, high-fat diets with anticonvulsant activity used primarily as a treatment for pediatric epilepsy. The anticonvulsant mechanism is thought to involve elevating inhibition and/or otherwise limiting excitability in the brain. Such a mechanism, however, might also significantly affect normal brain activity and limit synaptic plasticity, effects that would be important to consider in the developing brain. To assess ketogenic diet effects on synaptic transmission and plasticity, electrophysiological recordings were performed at the perforant path/dentate gyrus synapse in awake, freely-behaving juvenile male rats. Electrodes were implanted 1 week prior to recording. Animals were fed regular chow or a ketogenic diet ad libitum for 3 weeks before recording. Although the ketogenic diet did not significantly alter baseline excitability (assessed by input-output curves) or short-term plasticity (using the paired-pulse ratio), it did reduce the magnitude of long-term potentiation at all poststimulation timepoints out to the last time measured (48 h). The results suggest an effect of ketogenic diet-feeding on the induction magnitude but not the maintenance of long-term potentiation. The lack of effect of the diet on baseline transmission and the paired-pulse ratio suggests a mechanism that limits excitation preferentially in conditions of strong stimulation, consonant with clinical reports in which the ketogenic diet alleviates seizures without a major impact on normal brain activity. Limiting plasticity in a seizure-susceptible network may limit seizure-induced epileptogenesis which may subserve the ongoing benefit of the ketogenic diet in epilepsy. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  2. Simultaneous measurement of surface tension and viscosity using freely decaying oscillations of acoustically levitated droplets.

    Science.gov (United States)

    Kremer, J; Kilzer, A; Petermann, M

    2018-01-01

    Oscillations of small liquid drops around a spherical shape have been of great interest to scientists measuring physical properties such as interfacial tension and viscosity, over the last few decades. A powerful tool for contactless positioning is acoustic levitation, which has been used to simultaneously determine the surface tension and viscosity of liquids at ambient pressure. In order to extend this acoustic levitation measurement method to high pressure systems, the method is first evaluated under ambient pressure. To measure surface tension and viscosity using acoustically levitated oscillating drops, an image analysis method has to be developed and factors which may affect measurement, such as sound field or oscillation amplitude, have to be analyzed. In this paper, we describe the simultaneous measurement of surface tension and viscosity using freely decaying shape oscillations of acoustically levitated droplets of different liquids (silicone oils AK 5 and AK 10, squalane, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol) in air. These liquids vary in viscosity from 2 to about 30 mPa s. An acoustic levitation system, including an optimized standing wave acoustic levitator and a high-speed camera, was used for this study. An image analysis was performed with a self-written Matlab® code. The frequency of oscillation and the damping constant, required for the determination of surface tension and viscosity, respectively, were calculated from the evolution of the equatorial and polar radii. The results and observations are compared to data from the literature in order to analyze the accuracy of surface tension and viscosity determination, as well as the effect of non-spherical drop shape or amplitude of oscillation on measurement.

  3. 512-Channel and 13-Region Simultaneous Recordings Coupled with Optogenetic Manipulation in Freely Behaving Mice.

    Science.gov (United States)

    Xie, Kun; Fox, Grace E; Liu, Jun; Tsien, Joe Z

    2016-01-01

    The development of technologies capable of recording both single-unit activity and local field potentials (LFPs) over a wide range of brain circuits in freely behaving animals is the key to constructing brain activity maps. Although mice are the most popular mammalian genetic model, in vivo neural recording has been traditionally limited to smaller channel count and fewer brain structures because of the mouse's small size and thin skull. Here, we describe a 512-channel tetrode system that allows us to record simultaneously over a dozen cortical and subcortical structures in behaving mice. This new technique offers two major advantages - namely, the ultra-low cost and the do-it-yourself flexibility for targeting any combination of many brain areas. We show the successful recordings of both single units and LFPs from 13 distinct neural circuits of the mouse brain, including subregions of the anterior cingulate cortices, retrosplenial cortices, somatosensory cortices, secondary auditory cortex, hippocampal CA1, dentate gyrus, subiculum, lateral entorhinal cortex, perirhinal cortex, and prelimbic cortex. This 512-channel system can also be combined with Cre-lox neurogenetics and optogenetics to further examine interactions between genes, cell types, and circuit dynamics across a wide range of brain structures. Finally, we demonstrate that complex stimuli - such as an earthquake and fear-inducing foot-shock - trigger firing changes in all of the 13 brain regions recorded, supporting the notion that neural code is highly distributed. In addition, we show that localized optogenetic manipulation in any given brain region could disrupt network oscillations and caused changes in single-unit firing patterns in a brain-wide manner, thereby raising the cautionary note of the interpretation of optogenetically manipulated behaviors.

  4. From viscous to elastic sheets: Dynamics of smectic freely floating films

    Science.gov (United States)

    Stannarius, Ralf; Harth, Kirsten; May, Kathrin; Trittel, Torsten

    The dynamics of droplets and bubbles, particularly on microscopic scales, are of considerable importance in biological, environmental, and technical contexts. Soap bubbles, vesicles and components of biological cells are well known examples where the dynamic behavior is significantly influenced by the properties of thin membranes enclosed by fluids. Two-dimensional membrane motions couple to 3D shape transformations. Smectic liquid crystal mesogens form phases with internal molecular layer order. Free-standing films are easily prepared from this class of materials. They represent simple model systems for membrane dynamics and pattern formation in a quasi two-dimensional fluid. These films are usually spanned over a frame, and they can be inflated to bubbles on a support. Recently, closed microscopic shells of liquid-crystalline materials suspended in an outer fluid without contact to a solid support have been introduced and studied. With a special technique, we prepare millimetre to centimetre sized smectic bubbles in air (similar to soap bubbles). Their distinct feature is the fact that any change of surface area is coupled to a restructuring of the layers in the membrane. High-speed cameras are used to observe the shape transformations of freely floating bubbles from a distorted initial shape to a sphere. Bursting dynamics are recorded and compared to models. Most strikingly, an unpreceded cross-over from inviscid to viscous and elastic behaviour with increasing thickness of the membrane is found: Whereas thin bubbles behave almost like inviscid fluids, the relaxation dynamics slows down considerably for larger film thicknesses. Surface wrinkling and formation of extrusions are observed. We will present a characterization and an expalantion for the above phenomena.

  5. Effects of gradient and speed on freely chosen cadence: the key role of crank inertial load.

    Science.gov (United States)

    Sassi, Aldo; Rampinini, Ermano; Martin, David T; Morelli, Andrea

    2009-01-19

    The purpose of this study was to describe the relationship between road gradient (RG) and freely chosen cadence (FCC) in a group of professional cyclists during their normal training. In addition, a calculation of crank inertial load (CIL) was estimated in order to establish the relationship between FCC and CIL. Ten professional cyclists were monitored during training using commercially available power meters (Shoberer Rad Messtechnik (SRM), professional version). For each cyclist, recorded training sessions were reviewed to identify the hardest 6-8 training sessions (approximately 18 h of training). RG was estimated based on the relationship between power output, total mass and speed. The analysis was performed using 2113+/-317 samples of 30 s average data, collected on terrain ranging from -4%RG to 12%RG. The individual relationship between FCC and RG could be described by a linear regression model. There was a moderate correlation between FCC and CIL (group's r=0.42), and a multiple regression including the measured power output (WPO) increased the variance explained (R2=0.24). The correlation was very large between CIL and v (r=0.91), and was not strengthened by adding WPO as an independent variable (r=0.91). In conclusion, this investigation documents that in professional cyclists engaged in training, there is a linear decrease in FCC as RG increases (-4%RG and 12%RG). This decrease in FCC appears to be due to the reduction in v as slope increases. It is surmised that CIL plays a key role in the modulation of FCC.

  6. A low-cost multichannel wireless neural stimulation system for freely roaming animals

    Science.gov (United States)

    Alam, Monzurul; Chen, Xi; Fernandez, Eduardo

    2013-12-01

    Objectives. Electrical stimulation of nerve tissue and recording of neural activity are the basis of many therapies and neural prostheses. Conventional stimulation systems have a number of practical limitations, especially in experiments involving freely roaming subjects. Our main objective was to develop a modular, versatile and inexpensive multichannel wireless system able to overcome some of these constraints. Approach. We have designed and implemented a new multichannel wireless neural stimulator based on commercial components. The system is small (2 cm × 4 cm × 0.5 cm) and light in weight (9 g) which allows it to be easily carried in a small backpack. To test and validate the performance and reliability of the whole system we conducted several bench tests and in vivo experiments. Main results. The performance and accuracy of the stimulator were comparable to commercial threaded systems. Stimulation sequences can be constructed on-the-fly with 251 selectable current levels (from 0 to 250 µA) with 1 µA step resolution. The pulse widths and intervals can be as long as 65 ms in 2 µs time resolution. The system covers approximately 10 m of transmission range in a regular laboratory environment and 100 m in free space (line of sight). Furthermore it provides great flexibility for experiments since it allows full control of the stimulator and the stimulation parameters in real time. When there is no stimulation, the device automatically goes into low-power sleep mode to preserve battery power. Significance. We introduce the design of a powerful multichannel wireless stimulator assembled from commercial components. Key features of the system are their reliability, robustness and small size. The system has a flexible design that can be modified straightforwardly to tailor it to any specific experimental need. Furthermore it can be effortlessly adapted for use with any kind of multielectrode arrays.

  7. Head-mounted LED for optogenetic experiments of freely-behaving animal

    Science.gov (United States)

    Kwon, Ki Yong; Gnade, Andrew G.; Rush, Alexander D.; Patten, Craig D.

    2016-03-01

    Recent developments in optogenetics have demonstrated the ability to target specific types of neurons with sub-millisecond temporal precision via direct optical stimulation of genetically modified neurons in the brain. In most applications, the beam of a laser is coupled to an optical fiber, which guides and delivers the optical power to the region of interest. Light emitting diodes (LEDs) are an alternative light source for optogenetics and they provide many advantages over a laser based system including cost, size, illumination stability, and fast modulation. Their compact size and low power consumption make LEDs suitable light sources for a wireless optogenetic stimulation system. However, the coupling efficiency of an LED's output light into an optical fiber is lower than a laser due to its noncollimated output light. In typical chronic optogenetic experiment, the output of the light source is transmitted to the brain through a patch cable and a fiber stub implant, and this configuration requires two fiber-to-fiber couplings. Attenuation within the patch cable is potential source of optical power loss. In this study, we report and characterize a recently developed light delivery method for freely-behaving animal experiments. We have developed a head-mounted light source that maximizes the coupling efficiency of an LED light source by eliminating the need for a fiber optic cable. This miniaturized LED is designed to couple directly to the fiber stub implant. Depending on the desired optical power output, the head-mounted LED can be controlled by either a tethered (high power) or battery-powered wireless (moderate power) controller. In the tethered system, the LED is controlled through 40 gauge micro coaxial cable which is thinner, more flexible, and more durable than a fiber optic cable. The battery-powered wireless system uses either infrared or radio frequency transmission to achieve real-time control. Optical, electrical, mechanical, and thermal

  8. Freely distributed bed-net use among Chano Mille residents, south Ethiopia: a longitudinal study

    Directory of Open Access Journals (Sweden)

    Loha Eskindir

    2013-01-01

    Full Text Available Abstract Background A huge discrepancy was reported between ownership versus utilization of insecticide-treated bed nets (ITNs. To acquire the benefits of ITNs, households need to use and not merely own them. The objective of this study was to characterize the pattern of, and assess factors related to ITN use in one village in south Ethiopia. Methods A prospective cohort study involving 8,121 residents (in 1,388 households was carried out from April 2009 to April 2011 (101 weeks. Every week, individuals were asked whether they slept under an ITN the night before the interview. Descriptive statistics was used to report the availability and use of ITN. A negative, binomial, probability, distribution model was fitted to find out significant predictors of ITN use. Reasons for not using ITN were summarized. Results The total number of ITNs available at the beginning of the study was 1,631 (1.68 ITNs per household. On week 48, 3,099 new ITNs (PermaNet2.0 were distributed freely (2.3 ITNs per household. The number of households who received at least one new ITN was 1,309 (98.4%. The percentage of children Conclusions The ITN use fraction reached to a maximum of 69% despite near universal coverage (98.4% was achieved. Gender, age differences and distance from vector breeding site were associated with ITN use. Strategies may need to be designed addressing disproportions in ITN use, lack of convenient space to hang more than one ITN (for those receiving more than one, and measures to prolong usable life of ITNs.

  9. A wearable multi-channel fNIRS system for brain imaging in freely moving subjects.

    Science.gov (United States)

    Piper, Sophie K; Krueger, Arne; Koch, Stefan P; Mehnert, Jan; Habermehl, Christina; Steinbrink, Jens; Obrig, Hellmuth; Schmitz, Christoph H

    2014-01-15

    Functional near infrared spectroscopy (fNIRS) is a versatile neuroimaging tool with an increasing acceptance in the neuroimaging community. While often lauded for its portability, most of the fNIRS setups employed in neuroscientific research still impose usage in a laboratory environment. We present a wearable, multi-channel fNIRS imaging system for functional brain imaging in unrestrained settings. The system operates without optical fiber bundles, using eight dual wavelength light emitting diodes and eight electro-optical sensors, which can be placed freely on the subject's head for direct illumination and detection. Its performance is tested on N=8 subjects in a motor execution paradigm performed under three different exercising conditions: (i) during outdoor bicycle riding, (ii) while pedaling on a stationary training bicycle, and (iii) sitting still on the training bicycle. Following left hand gripping, we observe a significant decrease in the deoxyhemoglobin concentration over the contralateral motor cortex in all three conditions. A significant task-related ΔHbO2 increase was seen for the non-pedaling condition. Although the gross movements involved in pedaling and steering a bike induced more motion artifacts than carrying out the same task while sitting still, we found no significant differences in the shape or amplitude of the HbR time courses for outdoor or indoor cycling and sitting still. We demonstrate the general feasibility of using wearable multi-channel NIRS during strenuous exercise in natural, unrestrained settings and discuss the origins and effects of data artifacts. We provide quantitative guidelines for taking condition-dependent signal quality into account to allow the comparison of data across various levels of physical exercise. To the best of our knowledge, this is the first demonstration of functional NIRS brain imaging during an outdoor activity in a real life situation in humans. © 2013.

  10. Discriminating external and internal causes for heading changes in freely flying Drosophila.

    Directory of Open Access Journals (Sweden)

    Andrea Censi

    Full Text Available As animals move through the world in search of resources, they change course in reaction to both external sensory cues and internally-generated programs. Elucidating the functional logic of complex search algorithms is challenging because the observable actions of the animal cannot be unambiguously assigned to externally- or internally-triggered events. We present a technique that addresses this challenge by assessing quantitatively the contribution of external stimuli and internal processes. We apply this technique to the analysis of rapid turns ("saccades" of freely flying Drosophila melanogaster. We show that a single scalar feature computed from the visual stimulus experienced by the animal is sufficient to explain a majority (93% of the turning decisions. We automatically estimate this scalar value from the observable trajectory, without any assumption regarding the sensory processing. A posteriori, we show that the estimated feature field is consistent with previous results measured in other experimental conditions. The remaining turning decisions, not explained by this feature of the visual input, may be attributed to a combination of deterministic processes based on unobservable internal states and purely stochastic behavior. We cannot distinguish these contributions using external observations alone, but we are able to provide a quantitative bound of their relative importance with respect to stimulus-triggered decisions. Our results suggest that comparatively few saccades in free-flying conditions are a result of an intrinsic spontaneous process, contrary to previous suggestions. We discuss how this technique could be generalized for use in other systems and employed as a tool for classifying effects into sensory, decision, and motor categories when used to analyze data from genetic behavioral screens.

  11. Mapping Forest Canopy Height Across Large Areas by Upscaling ALS Estimates with Freely Available Satellite Data

    Directory of Open Access Journals (Sweden)

    Phil Wilkes

    2015-09-01

    Full Text Available Operational assessment of forest structure is an on-going challenge for land managers, particularly over large, remote or inaccessible areas. Here, we present an easily adopted method for generating a continuous map of canopy height at a 30 m resolution, demonstrated over 2.9 million hectares of highly heterogeneous forest (canopy height 0–70 m in Victoria, Australia. A two-stage approach was utilized where Airborne Laser Scanning (ALS derived canopy height, captured over ~18% of the study area, was used to train a regression tree ensemble method; random forest. Predictor variables, which have a global coverage and are freely available, included Landsat Thematic Mapper (Tasselled Cap transformed, Moderate Resolution Imaging Spectroradiometer Normalized Difference Vegetation Index time series, Shuttle Radar Topography Mission elevation data and other ancillary datasets. Reflectance variables were further processed to extract additional spatial and temporal contextual and textural variables. Modeled canopy height was validated following two approaches; (i random sample cross validation; and (ii with 108 inventory plots from outside the ALS capture extent. Both the cross validation and comparison with inventory data indicate canopy height can be estimated with a Root Mean Square Error (RMSE of ≤ 31% (~5.6 m at the 95th percentile confidence interval. Subtraction of the systematic component of model error, estimated from training data error residuals, rescaled canopy height values to more accurately represent the response variable distribution tails e.g., tall and short forest. Two further experiments were carried out to test the applicability and scalability of the presented method. Results suggest that (a no improvement in canopy height estimation is achieved when models were constructed and validated for smaller geographic areas, suggesting there is no upper limit to model scalability; and (b training data can be captured over a small

  12. Identification of Behaviour in Freely Moving Dogs (Canis familiaris) Using Inertial Sensors

    Science.gov (United States)

    Gerencsér, Linda; Vásárhelyi, Gábor; Nagy, Máté; Vicsek, Tamas; Miklósi, Adam

    2013-01-01

    Monitoring and describing the physical movements and body postures of animals is one of the most fundamental tasks of ethology. The more precise the observations are the more sophisticated the interpretations can be about the biology of a certain individual or species. Animal-borne data loggers have recently contributed much to the collection of motion-data from individuals, however, the problem of translating these measurements to distinct behavioural categories to create an ethogram is not overcome yet. The objective of the present study was to develop a “behaviour tracker”: a system composed of a multiple sensor data-logger device (with a tri-axial accelerometer and a tri-axial gyroscope) and a supervised learning algorithm as means of automated identification of the behaviour of freely moving dogs. We collected parallel sensor measurements and video recordings of each of our subjects (Belgian Malinois, N=12; Labrador Retrievers, N=12) that were guided through a predetermined series of standard activities. Seven behavioural categories (lay, sit, stand, walk, trot, gallop, canter) were pre-defined and each video recording was tagged accordingly. Evaluation of the measurements was performed by support vector machine (SVM) classification. During the analysis we used different combinations of independent measurements for training and validation (belonging to the same or different individuals or using different training data size) to determine the robustness of the application. We reached an overall accuracy of above 90% perfect identification of all the defined seven categories of behaviour when both training and validation data belonged to the same individual, and over 80% perfect recognition rate using a generalized training data set of multiple subjects. Our results indicate that the present method provides a good model for an easily applicable, fast, automatic behaviour classification system that can be trained with arbitrary motion patterns and potentially

  13. Comparison of implosion core metrics: A 10 ps dilation X-ray imager vs a 100 ps gated microchannel plate

    Science.gov (United States)

    Nagel, S. R.; Benedetti, L. R.; Bradley, D. K.; Hilsabeck, T. J.; Izumi, N.; Khan, S.; Kyrala, G. A.; Ma, T.; Pak, A.

    2016-11-01

    The dilation x-ray imager (DIXI) [T. J. Hilsabeck et al., Rev. Sci. Instrum. 81, 10E317 (2010); S. R. Nagel et al., ibid. 83, 10E116 (2012); S. R. Nagel et al., ibid. 85, 11E504 (2014)] is a high-speed x-ray framing camera that uses the pulse-dilation technique to achieve a temporal resolution of less than 10 ps. This is a 10 × improvement over conventional framing cameras currently employed on the National Ignition Facility (NIF) (100 ps resolution), and otherwise only achievable with 1D streaked imaging. A side effect of the dramatically reduced gate width is the comparatively lower detected signal level. Therefore we implement a Poisson noise reduction with non-local principal component analysis method [J. Salmon et al., J. Math. Imaging Vision 48, 279294 (2014)] to improve the robustness of the DIXI data analysis. Here we present results on ignition-relevant experiments at the NIF using DIXI. In particular we focus on establishing that/when DIXI gives reliable shape metrics (P0, P2, and P4 Legendre modes, and their temporal evolution/swings).

  14. Role of insulin receptor and insulin signaling on αPS2CβPS integrins' lateral diffusion.

    Science.gov (United States)

    Mainali, Dipak; Syed, Aleem; Arora, Neha; Smith, Emily A

    2014-12-01

    Integrins are ubiquitous transmembrane receptors with adhesion and signaling properties. The influence of insulin receptor and insulin signaling on αPS2CβPS integrins' lateral diffusion was studied using single particle tracking in S2 cells before and after reducing the insulin receptor expression or insulin stimulation. Insulin signaling was monitored by Western blotting for phospho-Akt expression. The expression of the insulin receptor was reduced using RNA interference (RNAi). After insulin receptor RNAi, four significant changes were measured in integrin diffusion properties: (1) there was a 24% increase in the mobile integrin population, (2) 14% of the increase was represented by integrins with Brownian diffusion, (3) for integrins that reside in confined zones of diffusion, there was a 45% increase in the diameter of the confined zone, and (4) there was a 29% increase in the duration integrins spend in confined zones of diffusion. In contrast to reduced expression of the insulin receptor, which alters integrin diffusion properties, insulin stimulation alone or insulin stimulation under conditions of reduced insulin receptor expression have minimal effects on altering the measured integrin diffusion properties. The differences in integrin diffusion measured after insulin receptor RNAi in the presence or absence of insulin stimulation may be the result of other insulin signaling pathways that are activated at reduced insulin receptor conditions. No change in the average integrin diffusion coefficient was measured for any conditions included in this study.

  15. Hydrogen sulfide down-regulates BACE1 and PS1 via activating PI3K/Akt pathway in the brain of APP/PS1 transgenic mouse.

    Science.gov (United States)

    He, Xuan-Li; Yan, Ning; Chen, Xiao-Shan; Qi, Yun-Wen; Yan, Yong; Cai, Zhiyou

    2016-10-01

    Endogenous hydrogen sulfide (H2S) may have multiple physiological functions in brain. Our previous study showed that H2S improved spatial memory impairment and decreased the production of Aβ in APP/PS1 transgenic mice. However, many of the underlying mechanisms are not still being elucidated. The aim of the present study is to investigate the neuroprotective mechanisms of H2S involving in the activity of β-secretase (BACE1), γ-secretase (PS1) and α-secretase (ADAM17). Morris water maze was used to measure the behavior change. The levels of Aβ40 and Aβ42 were quantified using colorimetric ELISA kits and immunohistochemical analysis. The levels of BACE1, PS1, ADAM17, pAkt, pp38MAPK, pERK and pJNK were tested by Western blot analysis in normal mice, APP/PS1 transgenic mice and 50μmol/kg-NaHS-treated transgenic mice. On the basis of exogenous H2S treatment, LY294002 (inhibitors of PI3K/Akt) or PD98059 (inhibitors of MAPK/ERK) was injected into lateral cerebral ventricle. The levels of BACE1, PS1 and pp38MAPK were increased and ADAM17 were decreased in the APP/PS1 transgenic mice. After intraperitoneal administration of an H2S donor (NaHS) into APP/PS1 mice, the levels of BACE1, PS1 and pp38MAPK were reduced and ADAM17 increased. The level of pp38 MAPKs, pAkt and pERK1/2 was increased in APP/PS1 transgenic mice compared with normal mice (ptransgenic mice and normal mice (p>0.05). These results demonstrated that LY294002 inhibited the effect of H2S on decreasing the BACE1 and PS1, reducing the level of Aβ and improving memory impairment in APP/PS1 transgenic mice. PD98059 had no influence on the expression of BACE1 and PS1. H2S inhibits the expression of BACE1 and PS1 by activating PI3K/Akt pathway in AD. Copyright © 2016 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  16. Development and characterization of sub-100 ps photomultiplier tubes.

    Science.gov (United States)

    Horsfield, C J; Rubery, M S; Mack, J M; Young, C S; Herrmann, H W; Caldwell, S E; Evans, S C; Sedilleo, T J; Kim, Y H; McEvoy, A; Milnes, J S; Howorth, J; Davis, B; O'Gara, P M; Garza, I; Miller, E K; Stoeffl, W; Ali, Z

    2010-10-01

    We describe the evaluation of a microchannel plate (MCP) photomultiplier tube (PMT), incorporating a 3 μm pore MCP and constant voltage anode and cathode gaps. The use of the small pore size results in PMTs with response functions of the order of 85 ps full-width-half-maximum, while the constant electric field across the anode and cathode gaps produces a uniform response function over the entire operating range of the device. The PMT was characterized on a number of facilities and employed on gas Cherenkov detectors fielded on various deuterium tritium fuel (DT) implosions on the Omega Laser Facility at the University of Rochester. The Cherenkov detectors are part of diagnostic development to measure Gamma ray reaction history for DT implosions on the National Ignition Facility.

  17. An Antiproton Decelerator in the CERN PS Complex

    CERN Document Server

    Riunaud, J P; Baird, S A; Boillot, J; Bosser, Jacques; Brouet, M; Caspers, Friedhelm; Chanel, M; Chohan, V; Eriksson, T; Garoby, R; Giannini, R; Giovannozzi, Massimo; Gruber, J; Hémery, J Y; Koziol, Heribert; MacCaferri, R; Maury, S; Metzmacher, K D; Möhl, D; Mulder, H; Pedersen, F; Perriollat, F; Poncet, Alain; Riunaud, J P; Serre, C; Simon, Daniel Jean; Tranquille, G; Tuyn, Jan Willem Nicolaas; Williams, B; Williams, D J

    1996-01-01

    The present CERN PS low-energy antiproton complex involves 4 machines to collect, cool, decelerate and supply experiments with up to 1010 antiprotons per pulse and per hour of momenta ranging from 0.1 to 2 GeV/c. In view of a possible future physics programme requiring low energy antiprotons, mainly to carry out studies on antihydrogen, a simplified scheme providing at low cost antiprotons at 100 MeV/c has been studied. It requires only one machine, the present Antiproton Collector (AC) converted into a cooler and decelerator (Antiproton Decelerator, AD) and delivering beam to experiments in the hall of the present Antiproton Accumulator Complex (AAC) [1]. This paper describes the feasibility study of such a scheme [2].

  18. MD on Head-Tail Instability in the PS Booster

    CERN Document Server

    Kornilov, V; Mikulec, B; Aumon, S; Rumolo, G

    2013-01-01

    Machine study experiments on the coherent instabilities appearing along the magnetic ramp have been performed at the CERN PS Booster synchrotron in the week of June 11-15, 2012. The space- and time structure of the head-tail instabilities was recorded by the triggered pick-up signals due to reproducibility of the occurrence time in the shot-by-shot sense. The intensity thresholds, the absolute growth rates and the mode structure have been compared for the bunches in the single-rf and in three types of the double-rf operation. The growth rates are compared to the instantaneous synchrotron frequencies, in the cases of the large corresponding ratio the head-tail mode structure is deformed by the driving impedance. Bunch parameters measurements indicate that the PSB bunches are in the regime of very strong transverse space-charge all along the magnetic ramp.

  19. Migrating the CERN PS control system to IBM workstations

    CERN Document Server

    De Metz-Noblat, N

    1995-01-01

    The workstations used within the control system of the CERN PS accelerator complex are not produced any more. We had therefore to review the software primary used as user interface and we achieved a port to IBM workstations. We are also preparing the maintenance of this code for the next ten years with minimal staff. This implies a clear separation between general computing facilities, control system developments, and operation. In order to share our experience, we will try to summarize various aspects of this migration: - system installation principles used to speed-up error recovery time and long-term maintenance costs, - problems correlated with the coexistence of two different platforms during migration, - software problems due to the platform and operating system changes, - hidden dependencies from a specific manufacturer.

  20. Multipole Stack for the 800 MeV PS Booster

    CERN Multimedia

    1975-01-01

    The 800 MeV PS Booster had seen first beam in its 4 superposed rings in 1972, routine operation began in 1973. In the strive for ever higher beam intensities, the need for additional multipole lenses became evident. After detailed studies, the manufacture of 8 stacks of multipoles was launched in 1974. Each stack consists of 4 superposed multipoles and each multipole has 4 concentric shells. From the innermost to the outermost shell, Type A contains octupole, skew-octupole, sextupole, skew-sextupole. Type B contains skew-octupole, skew-sextupole, vertical dipole, horizontal dipole. Completion of installation in 1976 opened the way to higher beam intensities. M. Battiaz is seen here with a multipole stack and its many electrical connections.

  1. First PS magnet unit, with members of the Magnet Group.

    CERN Multimedia

    CERN PhotoLab

    1956-01-01

    Members of the Magnet Group, sitting atop the first unit of the PS combined-function magnet. The picture was taken at the Institute of Physics of Geneva University, as CERN was still a muddy construction site at that time. All these people have now retired, but all of the magnets are still pulsing away. Front row (left to right): R.Tinguely, C.Germain, G.Plass, D.Neet, B.de Raad, M.Cavallaro, K.H.Reich, G.Kuhn, J.Nilsson, C.A.Ramm, Paillard. Second row: L.Resegotti, M.Niklaus, C.J.Zilverschoon, R.Bertolotto, Marcellin, G.Brianti, P.Collet. Standing behind: B.Kuiper.

  2. Surface morphology of PS-PDMS diblock copolymer films

    DEFF Research Database (Denmark)

    Andersen, T.H.; Tougaard, S.; Larsen, N.B.

    2001-01-01

    Spin coated thin films (∼400 Å) of poly(styrene)–poly(dimethylsiloxane) (PS–PDMS) diblock copolymers have been investigated using X-ray Photoelectron Spectroscopy and Atomic Force Microscopy. Surface segregation of the poly(dimethylsiloxane) blocks was studied for five diblock copolymers which...... by use of peak shape analysis of the X-ray Photoelectron Spectra via the Tougaard Method. The amount of dimethylsiloxane in the uppermost part of the films was quantified as a function of annealing time and temperature. For annealing above the PS glass transition temperature, surface segregation...... of the dimethylsiloxane chain-ends occurs for all the studied PS–PDMS diblock copolymers. At room temperature, surface segregation takes place only when the amount of dimethylsiloxane in the diblock copolymers is small....

  3. Sub-10ps monolithic and low-power photodetector readout

    Energy Technology Data Exchange (ETDEWEB)

    Varner, Gary S.; Ruckman, Larry L.

    2009-02-20

    Recent advances in photon detectors have resulted in high-density imaging arrays that offer many performance and cost advantages. In particular, the excellent transit time spread of certain devices show promise to provide tangible benefits in applications such as Positron Emission Tomography (PET). Meanwhile, high-density, high-performance readout techniques have not kept on pace for exploiting these developments. Photodetector readout for next generation high event rate particle identification and time-resolved PET requires a highly-integrated, low-power, and cost-effective readout technique. We propose fast waveform sampling as a method that meets these criteria and demonstrate that sub-10ps resolution can be obtained for an existing device.

  4. Small-size meshless 50 ps streak tube

    Science.gov (United States)

    Ageeva, N. V.; Andreev, S. V.; Belolipetski, V. S.; Bryukhnevich, G. I.; Greenfield, D. E.; Ivanova, S. R.; Kaverin, A. M.; Khohlova, A. N.; Kuz'menko, E. A.; Levina, G. P.; Makushina, V. A.; Monastyrskiy, M. A.; Schelev, M. Ya.; Semichastnova, Z. M.; Serdyuchenko, Yu. N.; Skaballanovich, T. A.; Sokolov, V. E.

    2008-11-01

    In contrast to the conventional image intensifier with large work area, a streak image tube should possess additional important feature - the comparatively small temporal distortion at the entire work area of the photocathode. With this additional engineering restriction taken into account, a novel small-size meshless streak image tube has been developed by means of numerical optimization. The tube with 25-mm wide work area contains a pair of deflection plates to sweep the electron image along the 25 mm output phosphor screen that is separated by 100 mm from the photocathode. The electron image can be shuttered with a 300 V blanking electric pulse. Electron-optical magnification of the tube is unit; spatial resolution reaches 30 lp/mm over the entire photocathode work area; temporal resolution lies in the 20 - 50 ps range, depending on the accelerating voltage (6 - 15 kV).

  5. Psödohipoparatiroidi Tip 1A: Olgu Sunumu

    Directory of Open Access Journals (Sweden)

    Mehmet Güven

    2017-06-01

    Full Text Available Psödohipoparatiroidizm (PHPT; hedef organın parathormona (PTH yanıt vermediği kalıtımsal bir bozukluktur. Biyokimyasal olarak; hipokalsemi, hiperfosfatemi ve PTH yüksekliği ile karakterizedir. PTH uygulamasına verilen yanıt belirgin derecede düşüktür. Tip 1A, biyokimyasal özelliklere ek olarak Albright herediter osteodistrofisi (AHO olarak bilinen karakteristik somatik bir fenotipe de sahiptir. Bu fenotipin, kısa boy, yuvarlak yüz, frontal bombelik, brakidaktili, obezite özelikleri bulunmaktadır. Burada biz, hipokalsemi ve Albright herediter osteodistrofisi tanısı koyduğumuz; kalsiyum, aktif D vitamini ile tedavi ettiğimiz olgumuzu sunduk.

  6. Updating the Psoriatic Arthritis (PsA) Core Domain Set: A Report from the PsA Workshop at OMERACT 2016.

    Science.gov (United States)

    Orbai, Ana-Maria; de Wit, Maarten; Mease, Philip J; Callis Duffin, Kristina; Elmamoun, Musaab; Tillett, William; Campbell, Willemina; FitzGerald, Oliver; Gladman, Dafna D; Goel, Niti; Gossec, Laure; Hoejgaard, Pil; Leung, Ying Ying; Lindsay, Chris; Strand, Vibeke; van der Heijde, Désirée M; Shea, Bev; Christensen, Robin; Coates, Laura; Eder, Lihi; McHugh, Neil; Kalyoncu, Umut; Steinkoenig, Ingrid; Ogdie, Alexis

    2017-10-01

    To include the patient perspective in accordance with the Outcome Measures in Rheumatology (OMERACT) Filter 2.0 in the updated Psoriatic Arthritis (PsA) Core Domain Set for randomized controlled trials (RCT) and longitudinal observational studies (LOS). At OMERACT 2016, research conducted to update the PsA Core Domain Set was presented and discussed in breakout groups. The updated PsA Core Domain Set was voted on and endorsed by OMERACT participants. We conducted a systematic literature review of domains measured in PsA RCT and LOS, and identified 24 domains. We conducted 24 focus groups with 130 patients from 7 countries representing 5 continents to identify patient domains. We achieved consensus through 2 rounds of separate surveys with 50 patients and 75 physicians, and a nominal group technique meeting with 12 patients and 12 physicians. We conducted a workshop and breakout groups at OMERACT 2016 in which findings were presented and discussed. The updated PsA Core Domain Set endorsed with 90% agreement by OMERACT 2016 participants included musculoskeletal disease activity, skin disease activity, fatigue, pain, patient's global assessment, physical function, health-related quality of life, and systemic inflammation, which were recommended for all RCT and LOS. These were important, but not required in all RCT and LOS: economic cost, emotional well-being, participation, and structural damage. Independence, sleep, stiffness, and treatment burden were on the research agenda. The updated PsA Core Domain Set was endorsed at OMERACT 2016. Next steps for the PsA working group include evaluation of PsA outcome measures and development of a PsA Core Outcome Measurement Set.

  7. Soil Monitor: an advanced and freely accesible platform to challenge soil sealing in Italy

    Science.gov (United States)

    Langella, Giuliano; Basile, Angelo; Giannecchini, Simone; Domenico Moccia, Francesco; Munafò, Michele; Terribile, Fabio

    2017-04-01

    Soil sealing is known to be one of the most serious soil degradation processes since it greatly disturbs or removes essential ecosystem services. Although important policy documents (Roadmap to a Resource Efficient in Europe, SDG'S) promise to mitigate this problem, there are still no signs of change and today soil sealing continues to increase globally. We believe an immediate action is required to reduce the distance between the grand policy declarations and the poor availability of operational - and scientifically robust - tools to challenge soil sealing. These tools must be able to support the decisions made by people who manage and control the soil sealing, namely urban and landscape planning professionals and authorities. In this contribution, we demonstrate that soil sealing can be effectively challenged by the implementation of a dedicated Geospatial Cyberinfrastructure. The platform we are developing - named Soil Monitor - is at now a well-functioning prototype freely available at http://www.soilmonitor.it/. It has been developed by research scientists coming from different disciplines. The national authority for environmental protection (ISPRA) provided the dataset while INU (Italian association of urban planners) tested the soil sealing and the urban planning indicators. More generally, Soil Monitor has been designed to support the Italian policy documents connected to soil sealing: AS 1181, AS 2383, L. 22 May 2015, n. 68; L. 28 December, n. 221). Thus, it connects many different soil sealing aspects including science, community, policy and economy. Soil Monitor performs geospatial computation in real-time to support the decision making in the landscape planning. This aims at measuring soil sealing in order to mitigate it and in particular at recognizing actions to achieve the land degradation neutrality. The web platform covers the entire Italy, even though it is "Country-agnostic". Data are processed at a very high spatial resolution (10-20 m), which

  8. Chemical Composition by the APXS along the Downhill Traverse of the Mars Exploration Rover Spirit at Gusev Crater

    Science.gov (United States)

    Brueckner, J.; Dreibus, G.; Gellert, R.; Clark, B. C.; Cohen, B.; McCoy, T.; Ming, D. W.; Mittlefehldt, D. W.; Yen, A.; Team, A. S.

    2006-12-01

    The Alpha Particle X-ray Spectrometer (APXS) onboard the Mars Exploration Rover Spirit continues to determine the elemental composition of samples at Gusev Crater. Starting around sol 600 the rover descended Husband Hill, which is part of the Columbia Hills, visited the inner basin with a large dune field, called `El Dorado', and parked at `Low Ridge' to conserve energy during the martian winter. Many unique samples were discovered by the instruments onboard Spirit during her downhill traverse. Here, we report only on the chemical data obtained by the APXS. The compositions of some of the soil samples are comparable to the mean soil determined along the earlier traverse. However, a light-toned subsurface sample (disturbed by the rover wheels), called `Dead Sea Samra', showed the highest sulfur content of all soil samples, the lowest Na, Mg, Al, Cl, K, Ca, Ti, Mn, and Zn, among the lowest Si and P, and among the highest Cr, Fe and Ni. Assuming ferric sulfate as a major mineral, large amounts of a pure silica phase must be present. Color and quantity of Dead Sea Samra resemble somewhat an earlier soil called `Paso Robles', though the latter is a mixture of sulfates with phosphate-rich soil. Manganese in Dead Sea Samra is so low that the Fe/Mn ratio exceeds 300, a value that has never been found previously on Mars (Fe/Mn ratio of 46 for Gusev basalts), indicating that only Fe3+ occurs. The dune field El Dorado contained granulated material that exhibited the highest Mg and Ni concentrations and the lowest S and Cl compared to all other soils implying an enrichment of olivine-rich sands. Two outcrops, called `Algonquin' and `Comanche', revealed compositions that differ significantly from those of earlier outcrops as they have the highest concentrations of Mg, Fe, and Ni (except for Ni in `Independence') and the lowest of Al, K (detection limit), Ca, and Ti of all brushed and almost all abraded rocks. Normative estimates assign them the highest olivine contents ever

  9. Chemical Composition by the APXS along the Downhill Traverse of the Mars Exploration Rover Spirit at Gusev Crater

    Science.gov (United States)

    Bruckner, J.; Dreibus, G.; Gellert, R.; Clark, B.C.; Cohen, B.; McCoy, T.; Ming, D.W.; Mittlefehldt, D.W.; Yen, A.; Athena Science Team

    2006-01-01

    The Alpha Particle X-ray Spectrometer (APXS) onboard the Mars Exploration Rover Spirit continues to determine the elemental composition of samples at Gusev Crater. Starting around sol 600 the rover descended Husband Hill, which is part of the Columbia Hills, visited the inner basin with a large dune field, called 'El Dorado', and parked at Low Ridge to conserve energy during the martian winter. Many unique samples were discovered by the instruments onboard Spirit during her downhill traverse. Here, we report only on the chemical data obtained by the APXS. The compositions of some of the soil samples are comparable to the mean soil determined along the earlier traverse. However, a light-toned subsurface sample (disturbed by the rover wheels), called Dead Sea Samra , showed the highest sulfur content of all soil samples, the lowest Na, Mg, Al, Cl, K, Ca, Ti, Mn, and Zn, among the lowest Si and P, and among the highest Cr, Fe and Ni. Assuming ferric sulfate as a major mineral, large amounts of a pure silica phase must be present. Color and quantity of Dead Sea Samra resemble somewhat an earlier soil called Paso Robles , though the latter is a mixture of sulfates with phosphate-rich soil. Manganese in Dead Sea Samra is so low that the Fe/Mn ratio exceeds 300, a value that has never been found previously on Mars (Fe/Mn ratio of 46 for Gusev basalts), indicating that only Fe(3+) occurs. The dune field El Dorado contained granulated material that exhibited the highest Mg and Ni concentrations and the lowest S and Cl compared to all other soils implying an enrichment of olivine-rich sands. Two outcrops, called Algonquin and Comanche , revealed compositions that differ significantly from those of earlier outcrops as they have the highest concentrations of Mg, Fe, and Ni (except for Ni in Independence) and the lowest of Al, K (detection limit), Ca, and Ti of all brushed and almost all abraded rocks. Normative estimates assign them the highest olivine contents ever found for

  10. First observation of o-Ps to p-Ps transition and first direct measurement of positronium hyperfine splitting with sub-THz light

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Takayuki, E-mail: yamazaki@icepp.s.u-tokyo.ac.jp; Miyazaki, Akira; Suehara, Taikan; Namba, Toshio; Asai, Shoji; Kobayashi, Tomio [University of Tokyo, Department of Physics, Graduate School of Science, and International Center for Elementary Particle Physics (Japan); Saito, Haruo [University of Tokyo, Graduate School of Arts and Sciences (Japan); Urushizaki, Yuichi; Ogawa, Isamu; Idehara, Toshitaka [University of Fukui, Research Center for Development of Far-Infrared Region (Japan); Sabchevski, Svilen [Bulgarian Academy of Sciences (Bulgaria)

    2012-12-15

    Positronium is an ideal system for the research of the bound state QED. The hyperfine splitting of positronium (Ps-HFS, about 203 GHz) is an important observable but all previous measurements of Ps-HFS had been measured indirectly using Zeeman splitting. There might be the unknown systematic errors on the uniformity of magnetic field. We are trying to measure Ps-HFS directly using sub-THz radiation. We developed an optical system to accumulate high power (about 10 kW) radiation in a Fabry-Perot resonant cavity and observed the positronium hyperfine transition for the first time.

  11. Delay-line cables for the fast bumpers in the PS.

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    For 'continuous transfer' to the SPS, the beam accelerated in the PS is shaved off over several turns, so as to form a continuous sequence of bunches several times the length of the PS circumference. Fast bumpers, powered in a 'staircase' way, displace the PS beam stepwise towards the ejection septum. Each step lasts 2.1 microsec and the cable drums in this picture contain some of the bumper delay-lines of altogether 10 km.

  12. A DiPS+ case study: a self-healing RADIUS server

    OpenAIRE

    Michiels, Sam; Desmet, Lieven; Verbaeten, Pierre

    2004-01-01

    This report shows performance results of a RADIUS implementation using the DiPS+ software architecture. In addition it compares this implementation with a commercially available RADIUS implementation, and shows that the DiPS+ architecture differentiates between user types and request types. In fact, the DiPS+ prototype prioritizes incoming traffic based on application-specifc preferences, and allocates the available processing resources to the highest priority requests.

  13. Microfabricated device for co-culture of sympathetic neuron and iPS-derived cardiomyocytes.

    Science.gov (United States)

    Takeuchi, Akimasa; Shimba, Kenta; Takayama, Yuzo; Kotani, Kiyoshi; Lee, Jong-Kook; Noshiro, Makoto; Jimbo, Yasuhiko

    2013-01-01

    Induced pluripotent stem (iPS) cell-derived cardiomyocytes (iPS-CMs) has been expected as a cell source for therapy of serious heart failure. However, it is unclear whether the function of iPS-CMs is modulated by the host sympathetic nervous system. Here we developed a device for co-culture of sympathetic neurons and iPS-CMs using microfabrication technique. The device consisted of a culture chamber and a microelectrode-array (MEA) substrate. The superior cervical ganglion (SCG) neurons were co-cultured with iPS-CMs in a microfabricated device, which had multiple compartments. Several days after seeding, synapses were formed between SCG neurons and iPS-CMs, as confirmed by immunostaining. Spontaneous electrical activities of the SCG neurons and the iPS-CMs were observed from the electrode of the MEA substrate. The beat rate of iPS-CMs increased after electrical stimulation of the co-cultured SCG neurons. Such changes in the beat rate were prevented in the presence of propranolol, a β-adrenoreceptor antagonist. These results suggest that the microfabricated device will be utilized for studying the functional modulation of iPS-CMs by connected sympathetic neurons.

  14. Facile Synthesis of Mono-Dispersed Polystyrene (PS/Ag Composite Microspheres via Modified Chemical Reduction

    Directory of Open Access Journals (Sweden)

    Wen Zhu

    2013-12-01

    Full Text Available A modified method based on in situ chemical reduction was developed to prepare mono-dispersed polystyrene/silver (PS/Ag composite microspheres. In this approach; mono-dispersed PS microspheres were synthesized through dispersion polymerization using poly-vinylpyrrolidone (PVP as a dispersant at first. Then, poly-dopamine (PDA was fabricated to functionally modify the surfaces of PS microspheres. With the addition of [Ag(NH32]+ to the PS dispersion, [Ag(NH32]+ complex ions were absorbed and reduced to silver nanoparticles on the surfaces of PS-PDA microspheres to form PS/Ag composite microspheres. PVP acted both as a solvent of the metallic precursor and as a reducing agent. PDA also acted both as a chemical protocol to immobilize the silver nanoparticles at the PS surface and as a reducing agent. Therefore, no additional reducing agents were needed. The resulting composite microspheres were characterized by TEM, field emission scanning electron microscopy (FESEM, energy-dispersive X-ray spectroscopy (EDS, XRD, UV-Vis and surface-enhanced Raman spectroscopy (SERS. The results showed that Ag nanoparticles (NPs were homogeneously immobilized onto the PS microspheres’ surface in the presence of PDA and PVP. PS/Ag composite microspheres were well formed with a uniform and compact shell layer and were adjustable in terms of their optical property.

  15. Lehtmets : psühhiaatria ei ole piisavalt atraktiivne / Andres Lehtmets ; interv. Marika Kusnets

    Index Scriptorium Estoniae

    Lehtmets, Andres

    2004-01-01

    Vestlus Eesti Psühhiaatrite Seltsi aseesimehega rahva vaimsest tervisest. Samas ka sotsiaalministeeriumi rahvatervise osakonna peaspetsialisti Helja Eomoisi kommentaar: Mida teeb ministeerium rahva vaimse tervise parandamiseks?

  16. Non-ionizing radiofrequency electromagnetic waves traversing the head can be used to detect cerebrovascular autoregulation responses.

    Science.gov (United States)

    Oziel, M; Hjouj, M; Gonzalez, C A; Lavee, J; Rubinsky, B

    2016-02-22

    Monitoring changes in non-ionizing radiofrequency electromagnetic waves as they traverse the brain can detect the effects of stimuli employed in cerebrovascular autoregulation (CVA) tests on the brain, without contact and in real time. CVA is a physiological phenomenon of importance to health, used for diagnosis of a number of diseases of the brain with a vascular component. The technology described here is being developed for use in diagnosis of injuries and diseases of the brain in rural and economically underdeveloped parts of the world. A group of nine subjects participated in this pilot clinical evaluation of the technology. Substantial research remains to be done on correlating the measurements with physiology and anatomy.

  17. Sustainable rural learning ecologies- a prolegomenon traversing transcendence of discursive notions of sustainability, social justice, development and food sovereignty

    Directory of Open Access Journals (Sweden)

    Dipane Hlalele

    2013-12-01

    Full Text Available This paper contributes, through traversing contested notions of sustainability, social justice, development and food sovereignty, to discourses around creation of sustainable rural learning ecologies. There has always been at least in the realm of scientific discourse, an attempt to dissociate the natural or physical environment from the social and human environment. This trend did not only affect the two spheres of existence only. It is further imbued and spawned fragmented and pervasive terminology, practices and human thought. Drawing from the ‘creating sustainable rural learning ecologies’ research project that commenced in 2011, I challenge and contest the use of such discourses and argue for the transcendence of such. This would, in my opinion, create space for harmonious and fluid co-existence between nature and humanity, such that the contribution of learning practices exudes and expedites sustainability in rural ecologies.

  18. A case study of the intraseasonal oscillation traversing the TOGA-COARE LSD. [large-scale domain

    Science.gov (United States)

    Vincent, Dayton G.; Schrage, Jon M.; Sliwinski, L. D.

    1993-01-01

    The paper presents examination of tree intraseasonal (30-60 day) oscillations (ISOs) that occurred during the southern summer season (December 1, 1985 - February 28, 1986) traversing the Large-Scale Domain (LSD) TOGA-COARE, the region which also plays an important role in ENSO, Australian monsoon, and extratropical circulations. Data presented include Hovmoeller diagrams of 5-day running means of 250-mb velocity potential anomalies and OLR anomalies; graphs of five-day running means of OLR in precipitable water (W) per sq m, averaged over 10 x 10 deg boxes centered on 5 S and (1) 145 E, (2) 155 E, (3) 165 E, and (4) 165 D, indicating the midpoint of each ISO; and vertical profiles of zonal wind in m/s averaged over the time period that each ISO spends in the 10 x 10 deg box centered at 5 S, and 175 E and 145 E.

  19. Non-contact method to freely control the radiation patterns of antenna with multi-folded transformation optics

    OpenAIRE

    Madni, Hamza Ahmad; Zheng, Bin; Zhu, Rongrong; Shen, Lian; Chen, Hongsheng; Xu, Zhiwei; Dehdashti, Shahram; Zhao, Yaodong; Wang, Huaping

    2017-01-01

    In this paper, we propose to use multi-folded transformation optics method to design a non-contact illusion device that can distantly and freely manipulate the radiation behavior of antenna located at a certain distance and such manipulation is enabled by the use of mapped electromagnetic medium coated with the transformed medium. The proposed design aims to achieve the radiation pattern of our choice from the antenna that does not possess any electromagnetic medium. Based on this, the functi...

  20. Examining the use of evidence-based and social media supported tools in freely accessible physical activity intervention websites

    OpenAIRE

    Vandelanotte, Corneel; Kirwan, Morwenna; Rebar, Amanda; Alley, Stephanie; Short, Camille; Fallon, Luke; Buzza, Gavin; Schoeppe, Stephanie; Maher, Carol; Duncan, Mitch J

    2014-01-01

    Background It has been shown that physical activity is more likely to increase if web-based interventions apply evidence-based components (e.g. self-monitoring) and incorporate interactive social media applications (e.g. social networking), but it is unclear to what extent these are being utilized in the publicly available web-based physical activity interventions. The purpose of this study was to evaluate whether freely accessible websites delivering physical activity interventions use evide...

  1. Exercise prior to a freely requested meal modifies pre and postprandial glucose profile, substrate oxidation and sympathovagal balance

    Directory of Open Access Journals (Sweden)

    Chapelot Didier

    2011-09-01

    Full Text Available Abstract Background The effects of exercise on glucose and metabolic events preceding and following a freely initiated meal have never been assessed. Moreover, the relationship between these events and sympathovagal balance is not known. The objective of this study was to determine whether exercise prior to a freely requested meal modifies the pre- and postprandial glucose profile, substrate oxidation and sympathovagal balance. Methods Nine young active male subjects consumed a standard breakfast (2298 ± 357 kJ. After 120 min, they either performed 75 min of exercise on a cycle ergometer (EX - 70% VO2max or rested (RT. Lunch was freely requested but eaten ad libitum only during the 1st session, and then energy intake was fixed across conditions. Glucose and sympathovagal balance were assessed continuously using a subcutaneous glucose monitoring system and analysis of heart rate variability, respectively. Every 5 min, a mean value was calculated for both glucose and sympathovagal balance. Substrate oxidation was determined by calculating the gas exchange ratio when lunch was requested and 180 min after the onset of eating. Results Preprandial glucose profiles were found in 72% of the sessions and with a similar frequency under both conditions. Meals were requested after a similar delay (40 ± 12 and 54 ± 10 min in EX and RT respectively; ns. At meal request, sympathovagal balance was not different between conditions but CHO oxidation was lower and fat oxidation higher in EX than in RT (-46% and +63%, respectively; both p Conclusions These results show that exercise does not impair preprandial glucose declines at the following meal freely requested, but leads to an increased postprandial glucose response and an elevated fat oxidation, an effect that vagal withdrawal may contribute to explain.

  2. Urocortin 1 administered into the hypothalamic supraoptic nucleus inhibits food intake in freely fed and food-deprived rats.

    Science.gov (United States)

    Fatima, A; Andrabi, S; Wolf, G; Engelmann, M; Spina, M G

    2013-03-01

    Peptides of the corticotropin-releasing hormone/Urocortin (CRH/Ucn) family are known to suppress appetite primarily via CRH(2) receptors. In the rat hypothalamic supraoptic nucleus (SON), synthesis of both Ucn1 and CRH(2) receptors has been reported, yet little is known about the effects of Ucn1 in the SON on feeding behaviour. We first established the dose-related effects of Ucn1 injected into the SON on the feeding response in both freely fed and 24-h food-deprived rats. A conditioned taste avoidance paradigm was performed to investigate possible generalised effects of local Ucn1 treatment. Administration of Ucn1 into the SON at doses equal to or higher than 0.5 μg significantly decreased food intake in both freely fed and food-deprived rats. The Ucn1-mediated suppression of food intake was delayed in freely fed as compared to food-deprived animals. Conditioning for taste aversion to saccharine appeared at 0.5 and 1 μg of Ucn1. Both the early and the delayed onset of anorexia observed after intra-SON injection of Ucn1 under fasting and fed conditions, respectively, suggest the possible involvement of different CRH receptor subtypes in the two conditions, while the conditioned taste aversion seems to be responsible for the initial latency to eat the first meal in these animals.

  3. Molecular characterization of plasmids pS7a and pS7b from Lactococcus lactis subsp. lactis bv. diacetylactis S50 as a base for the construction of mobilizable cloning vectors.

    Science.gov (United States)

    Strahinic, I; Kojic, M; Tolinacki, M; Fira, D; Topisirovic, L

    2009-01-01

    Strain Lactococcus lactis subsp. lactis bv. diacetylactis S50 harbours five theta-replicating plasmids (pS6, pS7a, pS7b, pS80 and pS140). The aim of this study was to characterize domains involved in the replication and conjugative mobilization of the small plasmids pS7a and pS7b, which are structurally very similar. Complete nucleotide sequences of pS7a and pS7b were determined by cloning DNA fragments of different sizes into Escherichia coli vectors. Linearized plasmids and four EcoRI fragments of the pS7a and pS7b were cloned into an origin probe vector. Constructed plasmids (pSEV10, pSK10, pISE1a and pISE1b) were able to replicate in the strain L. lactis subsp. cremoris MG1363. In addition, experiments showed that plasmids pS7a and pS7b contained oriT sequences and their conjugative transfer directly depended on the presence of pS80 in donor cells. Plasmids pS7a and pS7b contained typical lactococcal theta replication origin and repB gene that enable them to replicate in the strain L. lactis subsp. cremoris MG1363. Plasmid pS80 plays a key role in the conjugative transfer of small plasmids. Plasmids pS7a and pS7b-based derivatives could be valuable tools for genetic manipulation, studying processes of plasmid maintenance and horizontal gene transfer in lactococci.

  4. Neural stem cells differentiated from iPS cells spontaneously regain pluripotency.

    Science.gov (United States)

    Choi, Hyun Woo; Kim, Jong Soo; Choi, Sol; Hong, Yean Ju; Kim, Min Jung; Seo, Han Geuk; Do, Jeong Tae

    2014-10-01

    Differentiated somatic cells can be reprogrammed into pluripotent stem cells by transduction of exogenous reprogramming factors. After induced pluripotent stem (iPS) cells are established, exogenous genes are silenced. In the pluripotent state, retroviral genes integrated in the host genome are kept inactive through epigenetic transcriptional regulation. In this study, we tried to determine whether exogenous genes remain silenced or are reactivated upon loss of pluripotency or on differentiation using an in vitro system. We induced differentiation of iPS cells into neural stem cells (NSCs) in vitro; the NSCs appeared morphologically indistinguishable from brain-derived NSCs and stained positive for the NSC markers Nestin and Sox2. These iPS cell-derived NSCs (iPS-NSCs) were also capable of differentiating into all three neural subtypes. Interestingly, iPS-NSCs spontaneously formed aggregates on long-term culture and showed reactivation of the Oct4-GFP marker, which was followed by the formation of embryonic stem cell-like colonies. The spontaneously reverted green fluorescent protein (GFP)-positive (iPS-NSC-GFP(+) ) cells expressed high levels of pluripotency markers (Oct4 and Nanog) and formed germline chimeras, indicating that iPS-NSC-GFP(+) cells had the same pluripotency as the original iPS cells. The reactivation of silenced exogenous genes was tightly correlated with the downregulation of DNA methyltransferases (Dnmts) during differentiation of iPS cells. This phenomenon was not observed in doxycycline-inducible iPS cells, where the reactivation of exogenous genes could be induced only by doxycycline treatment. These results indicate that pluripotency can be regained through reactivation of exogenous genes, which is associated with dynamic change of Dnmt levels during differentiation of iPS cells. © 2014 AlphaMed Press.

  5. Phosphorene-directed self-assembly of asymmetric PS-b-PMMA block copolymer for perpendicularly-oriented sub-10 nm PS nanopore arrays

    Science.gov (United States)

    Zhang, Ziming; Zheng, Lu; Khurram, Muhammad; Yan, Qingfeng

    2017-10-01

    Few-layer black phosphorus, also known as phosphorene, is a new two-dimensional material which is of enormous interest for applications, mainly in electronics and optoelectronics. Herein, we for the first time employ phosphorene for directing the self-assembly of asymmetric polystyrene-block-polymethylmethacrylate (PS-b-PMMA) block copolymer (BCP) thin film to form the perpendicular orientation of sub-10 nm PS nanopore arrays in a hexagonal fashion normal to the interface. We experimentally demonstrate that none of the PS and PMMA blocks exhibit preferential affinity to the phosphorene-modified surface. Furthermore, the perpendicularly-oriented PS nanostructures almost stay unchanged with the variation of number of layers of few-layer phosphorene nanoflakes between 15-30 layers. Differing from the neutral polymer brushes which are widely used for chemical modification of the silicon substrate, phosphorene provides a novel physical way to control the interfacial interactions between the asymmetric PS-b-PMMA BCP thin film and the silicon substrate. Based on our results, it is possible to build a new scheme for producing sub-10 nm PS nanopore arrays oriented perpendicularly to the few-layer phosphorene nanoflakes. Furthermore, the nanostructural microdomains could serve as a promising nanolithography template for surface patterning of phosphorene nanoflakes.

  6. Measuring low picogram per liter concentrations of freely dissolved polychlorinated biphenyls in sediment pore water using passive sampling with polyoxymethylene.

    Science.gov (United States)

    Hawthorne, Steven B; Miller, David J; Grabanski, Carol B

    2009-11-15

    Studies into bioaccumulation of polychlorinated biphenyls (PCBs) have increasingly focused on congeners that are freely dissolved in sediment interstitial pore water. Because of their low water solubilities and their tendency to persist and concentrate as they progress in the food chain, interest has grown in methods capable of measuring individual PCB congeners at low part-per-quadrillion (picogram per liter) concentrations. Obtaining large volumes of pore water is difficult (or impossible), which makes conventional analytical approaches incapable of attaining suitable detection limits. In the present study, nondepletive sampling is used to achieve very low detection limits of freely dissolved PCBs, while requiring no separation of the sediment and water slurry. Commercially available 76 microm thick polyoxymethylene (POM) coupons were placed directly into wet sediments and left to reach equilibrium with the pore water and sediment PCBs for up to 84 days, with 28 days found to be sufficient. Freely dissolved concentrations were then calculated by dividing the PCB concentration found in the POM by its POM/water partitioning coefficient (K(POM)). The K(POM) values required for determining water concentrations were measured using two spiked sediments and two historically contaminated sediments for all 62 PCB congeners that are present at greater than trace concentrations in commercial Aroclors. Log K(POM) values ranged from ca. 4.6 for dichloro-congeners to ca. 7.0 for octachloro-congeners and correlate well with octanol/water coefficients (K(OW)) (r(2) = 0.947) so that a simple linear equation can be used to calculate dissolved concentrations within a factor of 2 or better for congeners having no measured K(POM) value. Detection limits for freely dissolved PCBs ranged from ca. 20 pg/L (part-per-quadrillion) for dichloro-congeners down to ca. 0.2 pg/L for higher-molecular-weight congeners. Sorption isotherms were found to be linear (r(2) > 0.995) over at least 3

  7. Beam lines from Linac 1 to PS and Booster

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    View against the direction of the proton beams. The 50 MeV Linac 1 is behind the concrete wall. Its beam emerges from the hole near the centre of the picture. A switching magnet directs the beam either to the PS (to the right in the sense of the beam; original injection line), or lets it go straight on to the Booster (originally 800 MeV, now 1.4 GeV). The huge drum in the line to the Booster is a "debuncher", driven by the 200 MHz RF of the linac. It reduces the beam's momentum spread. This was the last year of Linac 1 as provider of protons to the Booster. Linac 2, nearly completed at the time of this picture, took up trial delivery at the end of 1978, and routine delivery in 1979. The beam line from Linac 2, barely visible here, can be clearly seen on 7802260. Linac 1 had a second life as an ion accelerator.

  8. The (7,7) optics at CERN PS

    CERN Document Server

    Serluca, M; Efthymiopoulos, I; Sperati, F; Sterbini, G; Tecker, F; Zisopoulos, P

    2017-01-01

    The PS lattice is composed by one hundred combinedfunction magnets, which set the bare tune of the machineto (Qh,Qv) = (6.25, 6.28). Low energy quadrupoles areused at injection to move the tune in a limited working pointarea. In particular the vertical tune is moved below 6.25 toavoid the structural resonance 8Qv= 50 coupled with spacecharge, which leads to strong losses. In view of the highdemands in terms of beam brightness for LIU and HL-LHCprojects, the interest of exploring different integer tune work-ing area started during last years. During 2016, for the firsttime, it has been possible to explore the (7,7) tune workingarea at injection using the auxiliary circuits of the combinedfunction magnets. A finite-element magnetic model, underdevelopment, has been used to predict the required currentsin order to get the desired optical parameters. In this pa-per we present the results and issues encountered duringthe Machine Development (MD) studies about the injectionin the (7,7) area along with optics and be...

  9. Injection Bump Synchronization Study for the CERN PS

    CERN Document Server

    Serluca, Maurizio; Gilardoni, Simone; CERN. Geneva. ATS Department

    2016-01-01

    In the framework of the LHC Injector Upgrade (LIU) project the CERN PS injection kinetic energy will be upgraded from 1.4 to 2 GeV. The present injection bump is made by four bumpers in Straight Section (SS) 40, 42, 43, 44 and it will be converted in a five bumpers system to allow additional flexibility in the bump shape with a reduction of the proton losses during the bump closure. The injection section SS42 has being redesigned to accommodate a new eddy current septum which will host a new bumper magnet in the same vacuum vessel due to reduced longitudinal space availability. The synchronization and amplitude variation of the power converter of the in-vacuum bumper 42 with respect to the remaining outside vacuum bumpers 40, 41, 43, 44 can lead to orbit distortion and consequent losses during injection. In this note we present the experimental results from Machine Development (MD) studies along with simulations for the present system at 1.4 GeV to quantify the acceptable orbit distortion and the performance ...

  10. Scanning SQUID sampler with 40-ps time resolution

    Science.gov (United States)

    Cui, Zheng; Kirtley, John R.; Wang, Yihua; Kratz, Philip A.; Rosenberg, Aaron J.; Watson, Christopher A.; Gibson, Gerald W.; Ketchen, Mark B.; Moler, Kathryn. A.

    2017-08-01

    Scanning Superconducting QUantum Interference Device (SQUID) microscopy provides valuable information about magnetic properties of materials and devices. The magnetic flux response of the SQUID is often linearized with a flux-locked feedback loop, which limits the response time to microseconds or longer. In this work, we present the design, fabrication, and characterization of a novel scanning SQUID sampler with a 40-ps time resolution and linearized response to periodically triggered signals. Other design features include a micron-scale pickup loop for the detection of local magnetic flux, a field coil to apply a local magnetic field to the sample, and a modulation coil to operate the SQUID sampler in a flux-locked loop to linearize the flux response. The entire sampler device is fabricated on a 2 mm × 2 mm chip and can be scanned over macroscopic planar samples. The flux noise at 4.2 K with 100 kHz repetition rate and 1 s of averaging is of order 1 mΦ0. This SQUID sampler will be useful for imaging dynamics in magnetic and superconducting materials and devices.

  11. The directed differentiation of human iPS cells into kidney podocytes.

    Directory of Open Access Journals (Sweden)

    Bi Song

    Full Text Available The loss of glomerular podocytes is a key event in the progression of chronic kidney disease resulting in proteinuria and declining function. Podocytes are slow cycling cells that are considered terminally differentiated. Here we provide the first report of the directed differentiation of induced pluripotent stem (iPS cells to generate kidney cells with podocyte features. The iPS-derived podocytes share a morphological phenotype analogous with cultured human podocytes. Following 10 days of directed differentiation, iPS podocytes had an up-regulated expression of mRNA and protein localization for podocyte markers including synaptopodin, nephrin and Wilm's tumour protein (WT1, combined with a down-regulation of the stem cell marker OCT3/4. In contrast to human podocytes that become quiescent in culture, iPS-derived cells maintain a proliferative capacity suggestive of a more immature phenotype. The transduction of iPS podocytes with fluorescent labeled-talin that were immunostained with podocin showed a cytoplasmic contractile response to angiotensin II (AII. A permeability assay provided functional evidence of albumin uptake in the cytoplasm of iPS podocytes comparable to human podocytes. Moreover, labeled iPS-derived podocytes were found to integrate into reaggregated metanephric kidney explants where they incorporated into developing glomeruli and co-expressed WT1. This study establishes the differentiation of iPS cells to kidney podocytes that will be useful for screening new treatments, understanding podocyte pathogenesis, and offering possibilities for regenerative medicine.

  12. Emission properties of porphyrin compounds in new polymeric PS:CBP host

    Science.gov (United States)

    Jafari, Mohammad Reza; Bahrami, Bahram

    2015-06-01

    In this study, a device with fundamental structure of ITO/PEDOT:PSS (60 nm)/PS:CBP (70 nm)/Al (150 nm) was fabricated. The electroluminescence spectrum of device designated a red shift rather than PS:CBP photoluminescence spectra. It can be suggested that the electroplex emission occurs at PS:CBP interface. By following this step, red light-emitting devices using porphyrin compounds as a red dopant in a new host material PS:CBP with a configuration of ITO/PEDOT:PSS (60 nm)/PS:CBP:porphyrin compounds(70 nm)/Al (150 nm) have been fabricated and investigated. The electroluminescent spectra of the porphyrin compounds were red-shifted as compared with the PS:CBP blend. OLED devices based on doping 3,4PtTPP and TPPNO2 in PS:CBP showed purer red emission compared with ZnTPP and CoTPP doped devices. We believe that the electroluminescence performance of OLED devices based on porphyrin compounds depends on overlaps between the absorption of the porphyrin compounds and the emission of PS:CBP.

  13. Composite Si/PS membrane pressure sensors with micro and macro ...

    Indian Academy of Sciences (India)

    Porous Silicon (PS) is a versatile material with many unique features making it viable in the field of Microelectromechanical Systems (MEMS). In this paper, we discuss the optimization of formation parameters of micro and macro PS with different porosity and thickness for use in pressure sensors. The optimized material is ...

  14. Sonication-assisted synthesis of polystyrene (PS)/organoclay nanocomposites: influence of clay content

    Science.gov (United States)

    Suresh, Kelothu; Kumar, R. Vinoth; Kumar, Manish; Jeyapriya, M.; Anbarasan, R.; Pugazhenthi, G.

    2017-06-01

    This article presents the synthesis of a series of polystyrene (PS)/organoclay nanocomposite films consisting of different contents of clay (1-7 wt%) by sonication-coupled solvent-blending technique. The prepared PS nanocomposite films were characterized using various techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA). The XRD and TEM results revealed the formation of exfoliated nanocomposites at lower loading of organoclay (<5 wt%). The presence of various functional groups in the organoclay and PS/organoclay nanocomposite was verified by FTIR spectra. The thermal stability of PS nanocomposites was significantly improved as compared to pristine PS, which is evident from TGA analysis. When 10% mass loss was chosen as a point of reference, the thermal degradation temperature of PS nanocomposite holding 7 wt% of organoclay was found to be 30 °C more over pristine PS. The thermal kinetic parameters such as activation energy ( E a), pre-exponential factor ( A), and the order of reaction ( n) were determined by employing the Coats-Redfern model. Thermal degradation reaction mechanism of PS nanocomposites was also investigated.

  15. [Methionine metabolism regulates maintenance and differentiation of human ES/iPS cells].

    Science.gov (United States)

    Shiraki, Nobuaki; Kume, Shoen

    2015-05-01

    Embryonic stem (ES) and induced pluripotent stem (iPS) cells are pluripotent and can give rise to all cell types. ES/iPS cells have a unique transcriptional circuit that sustains the pluripotent state. These cells also possess a characteristically high rate of proliferation as well as an abbreviated G1 phase. These unique molecular properties distinguish ES and iPS cells from somatic cells. Mouse ES/iPS cells are in a high-flux metabolic state, with a high dependence on threonine catabolism. However, little is known about amino acid metabolism in human ES/iPS cells. Recently, we reported that human ES/iPS cells require high amounts of methionine (Met) and express high levels of Met metabolism enzymes (Shriaki N, et al: Cell Metabolism, 2014). Met deprivation results in a rapid decrease in intracellular S-adenosyl-methionine (SAM), triggering the activation of p53 signaling, reducing pluripotent marker gene NANOG expression, and poising human ES/iPS cells for differentiation, follow by potentiated differentiation into all three germ layers. However, when exposed to prolonged Met deprivation, the cells went to apoptosis. In this review, we explain the importance of SAM in Met metabolism and its relationship with pluripotency, cell survival, and differentiation of human ES/iPS cells.

  16. Effects of hypoxia on pluripotency in murine iPS cells.

    Science.gov (United States)

    Sugimoto, Kouji; Yoshizawa, Yuu; Yamada, Shizuka; Igawa, Kazunari; Hayashi, Yoshihiko; Ishizaki, Hidetaka

    2013-10-01

    Retroviral transduction of four transcription factors (Oct4, Sox2, Klf4 and c-Myc) or three factors, excluding c-Myc, has been shown to initiate a reprogramming process that results in the transformation of murine fibroblasts to induced pluripotent stem (iPS) cells, and there has been a rapid increase in the number of iPS cell-based preclinical trials. In this study, the effects of these transcription factors were evaluated regarding the growth and differentiation of murine iPS cells under hypoxia. Based on the results of RT-PCR and alizarin red S staining, there were no statistical differences in the growth and differentiation of iPS cells or the induction of iPS cells to osteoblasts under hypoxia between the transcription factor groups. Furthermore, the function of hypoxia inducible factors (HIFs) in murine iPS cells under hypoxia was investigated in relation to the morphology and expression of transcription factors using RT-PCR and Western blotting. The HIF-2α knockdown group exhibited a decrease in the colony size of the iPS cells. The HIF-2α or -3α knockdown group demonstrated a statistically significant decrease in the transcription factor expression compared to that observed in the control group. These results demonstrate that HIF-2α among HIFs is the most influential candidate for the maintenance of the pluripotency of murine iPS cells. Copyright © 2013 Wiley Periodicals, Inc.

  17. 7 CFR 1753.37 - Plans and specifications (P&S).

    Science.gov (United States)

    2010-01-01

    ....37 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE... Installation of Central Office Equipment § 1753.37 Plans and specifications (P&S). (a) General. (1) Prior to... central office equipment. (2) The P&S shall specify the delivery and completion time required for each...

  18. Rahuoperatsioonide Keskuses alustab sotsiaalse ja psühholoogilise toetuse sektsioon / Merle Tihaste, Marge Sillaste

    Index Scriptorium Estoniae

    Parmak, Merle, 1968-

    2008-01-01

    Missioonidel osalevatele või pikaajalises lähetuses viibivatele kaitseväelastele ja nende peredele suunatud sotsiaalse ja psühholoogilise toetuse tagamiseks loodud sektsioonist Rahuoperatsioonide Keskuse koosseisus. Sektsiooni töömudelist, ülesannetest ja koostöövõrgustikust. Skeem: Sotsiaalse ja psühholoogilise toetuse sektsiooni töömudel ja partnerid

  19. PS Dreyer: Bakens op die pad van die wetenskap | Antonites | HTS ...

    African Journals Online (AJOL)

    PS Dreyer: Beacons on the path of science. Professor PS Dreyer is an academic who has shovsm insight and vision into several problems of the human sciences since 1951. He has identified problems, but also contributed solutions to them. In this respect his philosophy on causality and freedom is of utmost importance.

  20. Preliminary Evaluation of PS300: A New Self-Lubricating High Temperature Composite Coating for Use to 800 C

    Science.gov (United States)

    Dellacorte, C.; Edmonds, B. J.

    1995-01-01

    This paper introduces PS300, a plasma sprayed, self-lubricating composite coating for use in sliding contacts at temperatures to 800 C. PS300 is a metal bonded chrome oxide coating with silver and BaF2/CaF2 eutectic solid lubricant additives. PS300 is similar to PS200, a chromium carbide based coating, which is currently being investigated for a variety of tribological applications. In pin-on-disk testing up to 650 C, PS300 exhibited comparable friction and wear properties to PS200. The PS300 matrix, which is predominantly chromium oxide rather than chromium carbide, does not require diamond grinding and polishes readily with silicon carbide abrasives greatly reducing manufacturing costs compared to PS200. It is anticipated that PS300 has potential for sliding bearing and seal applications in both aerospace and general industry.

  1. Retinoid Uptake, Processing, and Secretion in Human iPS-RPE Support the Visual Cycle

    Science.gov (United States)

    Muñiz, Alberto; Greene, Whitney A.; Plamper, Mark L.; Choi, Jae Hyek; Johnson, Anthony J.; Tsin, Andrew T.; Wang, Heuy-Ching

    2014-01-01

    Purpose. Retinal pigmented epithelium derived from human induced pluripotent stem (iPS) cells (iPS-RPE) may be a source of cells for transplantation. For this reason, it is essential to determine the functional competence of iPS-RPE. One key role of the RPE is uptake and processing of retinoids via the visual cycle. The purpose of this study is to investigate the expression of visual cycle proteins and the functional ability of the visual cycle in iPS-RPE. Methods. iPS-RPE was derived from human iPS cells. Immunocytochemistry, RT-PCR, and Western blot analysis were used to detect expression of RPE genes lecithin-retinol acyl transferase (LRAT), RPE65, cellular retinaldehyde-binding protein (CRALBP), and pigment epithelium–derived factor (PEDF). All-trans retinol was delivered to cultured cells or whole cell homogenate to assess the ability of the iPS-RPE to process retinoids. Results. Cultured iPS-RPE expresses visual cycle genes LRAT, CRALBP, and RPE65. After incubation with all-trans retinol, iPS-RPE synthesized up to 2942 ± 551 pmol/mg protein all-trans retinyl esters. Inhibition of LRAT with N-ethylmaleimide (NEM) prevented retinyl ester synthesis. Significantly, after incubation with all-trans retinol, iPS-RPE released 188 ± 88 pmol/mg protein 11-cis retinaldehyde into the culture media. Conclusions. iPS-RPE develops classic RPE characteristics and maintains expression of visual cycle proteins. The results of this study confirm that iPS-RPE possesses the machinery to process retinoids for support of visual pigment regeneration. Inhibition of all-trans retinyl ester accumulation by NEM confirms LRAT is active in iPS-RPE. Finally, the detection of 11-cis retinaldehyde in the culture medium demonstrates the cells' ability to process retinoids through the visual cycle. This study demonstrates expression of key visual cycle machinery and complete visual cycle activity in iPS-RPE. PMID:24255038

  2. Retinoid uptake, processing, and secretion in human iPS-RPE support the visual cycle.

    Science.gov (United States)

    Muñiz, Alberto; Greene, Whitney A; Plamper, Mark L; Choi, Jae Hyek; Johnson, Anthony J; Tsin, Andrew T; Wang, Heuy-Ching

    2014-01-09

    Retinal pigmented epithelium derived from human induced pluripotent stem (iPS) cells (iPS-RPE) may be a source of cells for transplantation. For this reason, it is essential to determine the functional competence of iPS-RPE. One key role of the RPE is uptake and processing of retinoids via the visual cycle. The purpose of this study is to investigate the expression of visual cycle proteins and the functional ability of the visual cycle in iPS-RPE. iPS-RPE was derived from human iPS cells. Immunocytochemistry, RT-PCR, and Western blot analysis were used to detect expression of RPE genes lecithin-retinol acyl transferase (LRAT), RPE65, cellular retinaldehyde-binding protein (CRALBP), and pigment epithelium-derived factor (PEDF). All-trans retinol was delivered to cultured cells or whole cell homogenate to assess the ability of the iPS-RPE to process retinoids. Cultured iPS-RPE expresses visual cycle genes LRAT, CRALBP, and RPE65. After incubation with all-trans retinol, iPS-RPE synthesized up to 2942 ± 551 pmol/mg protein all-trans retinyl esters. Inhibition of LRAT with N-ethylmaleimide (NEM) prevented retinyl ester synthesis. Significantly, after incubation with all-trans retinol, iPS-RPE released 188 ± 88 pmol/mg protein 11-cis retinaldehyde into the culture media. iPS-RPE develops classic RPE characteristics and maintains expression of visual cycle proteins. The results of this study confirm that iPS-RPE possesses the machinery to process retinoids for support of visual pigment regeneration. Inhibition of all-trans retinyl ester accumulation by NEM confirms LRAT is active in iPS-RPE. Finally, the detection of 11-cis retinaldehyde in the culture medium demonstrates the cells' ability to process retinoids through the visual cycle. This study demonstrates expression of key visual cycle machinery and complete visual cycle activity in iPS-RPE.

  3. Inhibition of Ps Formation in Benzene and Cyclohexane by CH3CI and CH3Br

    DEFF Research Database (Denmark)

    Wikander, G.; Mogensen, O. E.; Pedersen, Niels Jørgen

    1983-01-01

    Positron-annihilation lifetime spectra have been measured for mixtures of CH3Cl and CH3Br in cyclohexane and of CH3Cl in benzene. The ortho-positronium (Ps) yield decreased monotonically from 38% and 43% in cyclohexane and benzene respectively to 11% in pure CH3Cl and 6% in pure CH3Br. The strength......− anions to form Ps. while it forms a bound state with the halides. X−. CH3Cl was a roughly three times weaker Ps inhibitor in benzene than in cyclohexane, which shows that CH3Cl− does not dechlorinate in times comparable to or shorter than 400–500 ps in benzene. An improved model for the explanation of Ps...

  4. Chemical resistance of core-shell particles (PS/PMMA polymerized by seeded suspension

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Belchior Ribeiro

    2017-09-01

    Full Text Available Abstract Core-shell particles were produced on seeded suspension polymerization by using polystyrene (PS as polymer core, or seed, and methyl methacrylate (MMA as the shell forming monomer. Two synthesis routes were evaluated by varying the PS seed conversion before MMA addition. The main purpose of this work was to investigate the influence of synthesis routes on the morphology and chemical resistance of the resulting particles. 1H NMR spectroscopy showed that the use of PS seeds with lower conversion led to the formation of higher amount of poly(styrene-co-MMA. The copolymer acted as a compatibilizer, decreasing the interfacial energy between both homopolymers. As a consequence, a larger amount of reduced PMMA cluster were formed, as was revealed by TEM measurements. Samples in this system showed enhanced resistance to cyclohexane attack compared with pure PS, with a PS extraction of only 37% after 54 hours test.

  5. iPS cell technologies: significance and applications to CNS regeneration and disease

    Science.gov (United States)

    2014-01-01

    In 2006, we demonstrated that mature somatic cells can be reprogrammed to a pluripotent state by gene transfer, generating induced pluripotent stem (iPS) cells. Since that time, there has been an enormous increase in interest regarding the application of iPS cell technologies to medical science, in particular for regenerative medicine and human disease modeling. In this review article, we outline the current status of applications of iPS technology to cell therapies (particularly for spinal cord injury), as well as neurological disease-specific iPS cell research (particularly for Parkinson’s disease and Alzheimer’s disease). Finally, future directions of iPS cell research are discussed including a) development of an accurate assay system for disease-associated phenotypes, b) demonstration of causative relationships between genotypes and phenotypes by genome editing, c) application to sporadic and common diseases, and d) application to preemptive medicine. PMID:24685317

  6. Formation of positron-atom bound states in collisions between Rydberg Ps and neutral atoms

    CERN Document Server

    Swann, A R; Deller, A; Gribakin, G F

    2016-01-01

    Predicted twenty years ago, positron binding to neutral atoms has not yet been observed experimentally. A new scheme is proposed to detect positron-atom bound states by colliding Rydberg positronium (Ps) with neutral atoms. Estimates of the charge-transfer-reaction cross section are obtained using the first Born approximation for a selection of neutral atom targets and a wide range of incident Ps energies and principal quantum numbers. We also estimate the corresponding Ps ionization cross section. The accuracy of the calculations is tested by comparison with earlier predictions for Ps charge transfer in collisions with hydrogen and antihydrogen. We describe an existing Rydberg Ps beam suitable for producing positron-atom bound states and estimate signal rates based on the calculated cross sections and realistic experimental parameters. We conclude that the proposed methodology is capable of producing such states and of testing theoretical predictions of their binding energies.

  7. Tribology and Microstructure of PS212 with a Cr2O3 Seal Coat

    Science.gov (United States)

    Sliney, Harold E.; Benoy, Patricia A.; Korenyi-Both, Andras; Dellacorte, Christopher

    1994-01-01

    PS212 is a plasma sprayed metal bonding chrome carbide coating with solid lubricant additives which has lubricating properties at temperatures up to about 900 deg C. The coating is diamond ground to achieve an acceptable tribological surface. But, as with many plasma spray coatings, PS212 is not fully-dense. In this study, a chromium oxide base seal coating is used in an attempt to seal any porosity that is open to the surface of the PS212 coating, and to study the effect of the sealant on the tribological properties of PS212. The results indicate that the seal coating reduces friction and wear when it is applied and then diamond ground leaving a thin layer of seal coating which fills in the surface pits of the PS212 coating.

  8. Effects of Traverse Scanning Speed of Spray Nozzle on the Microstructure and Mechanical Properties of Cold-Sprayed Ti6Al4V Coatings

    Science.gov (United States)

    Tan, Adrian Wei-Yee; Sun, Wen; Phang, Yun Peng; Dai, Minghui; Marinescu, Iulian; Dong, Zhili; Liu, Erjia

    2017-10-01

    Cold spray has the potential to restore damaged aerospace components made from titanium alloy, Ti6Al4V at low temperature (200-400 °C). Traverse scanning speed during deposition is one of the key factors that affect the quality of the Ti6Al4V coatings as it influences the thermal build-up and coating thickness per pass. As there are fewer reported studies on this, this work investigated the effects of different traverse scanning speeds (100, 300 and 500 mm/s) of cold spray nozzle on the microstructure and mechanical properties of cold-sprayed Ti6Al4V coatings. The cross-sectional analysis showed coating porosities reduces with slower traverse speed, from 3.2 to 0.5%. In addition, the microhardness of the coatings increased from about 361-385 HV due to strain hardening. However, the adhesion strength of the coatings to the substrates significantly decreased with reduced traverse speed from about 60 MPa (glue failure) at 500 mm/s to 2.5 MPa (interface failure) at 100 mm/s. Therefore, this study revealed that the control of heat build-up and thickness per pass during the cold spray deposition of the Ti6Al4V coatings is crucial to attain the desirable properties of the coatings.

  9. Proposing an International Collaboration on Lightweight Autonomous Vehicles to Conduct Scientific Traverses and Surveys over Antarctica and the Surrounding Sea Ice

    Science.gov (United States)

    Carsey, Frank; Behar, Alberto

    2004-01-01

    We have continued to develop a concept for use of autonomous rovers, originally developed for use in planetary exploration, in polar science on Earth; the concept was the subject of a workshop, and this report summarizes and extends that workshop. The workshop on Antarctic Autonomous Scientific Vehicles and Traverses met at the National Geographic Society on February 14 and 15, 2001 to discuss scientific objectives and benefits of the use of autonomous rovers. The participants enthusiastically viewed rovers as being uniquely valuable for such tasks as data taking on tedious or repetitive routes, traverses in polar night, difficult or hazardous routes, extremely remote regions, routes requiring only simple instrumentation, traverses that must be conducted at low speed, augments of manned traverses, and scientific procedures not compatible with human presence or combustion engines. The workshop has concluded that instrumented autonomous vehicles, of the type being developed for planetary exploration, have the potential to contribute significantly to the way science in conducted in Antarctica while also aiding planetary technology development, and engaging the public's interest. Specific objectives can be supported in understanding ice sheet mass balance, sea ice heat and momentum exchange, and surface air chemistry processes. In the interval since the workshop, we have concluded that organized program to employ such rovers to perform scientific tasks in the Fourth International Polar Year would serve the objectives of that program well.

  10. Intron-exon organization of the active human protein S gene PS. alpha. and its pseudogene PS. beta. : Duplication and silencing during primate evolution

    Energy Technology Data Exchange (ETDEWEB)

    Ploos van Amstel, H.; Reitsma, P.H.; van der Logt, C.P.; Bertina, R.M. (University Hospital, Leiden (Netherlands))

    1990-08-28

    The human protein S locus on chromosome 3 consists of two protein S genes, PS{alpha} and PS{beta}. Here the authors report the cloning and characterization of both genes. Fifteen exons of the PS{alpha} gene were identified that together code for protein S mRNA as derived from the reported protein S cDNAs. Analysis by primer extension of liver protein S mRNA, however, reveals the presence of two mRNA forms that differ in the length of their 5{prime}-noncoding region. Both transcripts contain a 5{prime}-noncoding region longer than found in the protein S cDNAs. The two products may arise from alternative splicing of an additional intron in this region or from the usage of two start sites for transcription. The intron-exon organization of the PS{alpha} gene fully supports the hypothesis that the protein S gene is the product of an evolutional assembling process in which gene modules coding for structural/functional protein units also found in other coagulation proteins have been put upstream of the ancestral gene of a steroid hormone binding protein. The PS{beta} gene is identified as a pseudogene. It contains a large variety of detrimental aberrations, viz., the absence of exon I, a splice site mutation, three stop codons, and a frame shift mutation. Overall the two genes PS{alpha} and PS{beta} show between their exonic sequences 96.5% homology. Southern analysis of primate DNA showed that the duplication of the ancestral protein S gene has occurred after the branching of the orangutan from the African apes. A nonsense mutation that is present in the pseudogene of man also could be identified in one of the two protein S genes of both chimpanzee and gorilla. This implicates that silencing of one of the two protein S genes must have taken place before the divergence of the three African apes.

  11. PS2013 Satellite Workshop on Photosynthetic Light-Harvesting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Niederman, Robert A. [Rutgers Univ., New Brunswick, NJ (United States); Blankenship, Robert E. [Washington Univ., St. Louis, MO (United States); Frank, Harry A. [Univ. of Connecticut, Storrs, CT (United States)

    2015-02-07

    These funds were used for partial support of the PS2013 Satellite Workshop on Photosynthetic Light-Harvesting Systems, that was held on 8-11 August, 2013, at Washington University, St. Louis, MO. This conference, held in conjunction with the 16th International Congress on Photosynthesis/St. Louis, continued a long tradition of light-harvesting satellite conferences that have been held prior to the previous six international photosynthesis congresses. In this Workshop, the basis was explored for the current interest in replacing fossil fuels with energy sources derived form direct solar radiation, coupled with light-driven electron transport in natural photosynthetic systems and how they offer a valuable blueprint for conversion of sunlight to useful energy forms. This was accomplished through sessions on the initial light-harvesting events in the biological conversion of solar energy to chemically stored energy forms, and how these natural photosynthetic processes serve as a guide to the development of robust bio-hybrid and artificial systems for solar energy conversion into both electricity or chemical fuels. Organized similar to a Gordon Research Conference, a lively, informal and collegial setting was established, highlighting the exchange of exciting new data and unpublished results from ongoing studies. A significant amount of time was set aside for open discussion and interactive poster sessions, with a special session devoted to oral presentations by talented students and postdoctoral fellows judged to have the best posters. This area of research has seen exceptionally rapid progress in recent years, with the availability of a number of antenna protein structures at atomic resolution, elucidation of the molecular surface architecture of native photosynthetic membranes by atomic force microscopy and the maturing of ultrafast spectroscopic and molecular biological techniques for the investigation and manipulation of photosynthetic systems. The conferees

  12. Crevasse Detection and Avoidance for Safe Traversing on the Dynamic and Annually Changing Margin of the Greenland Ice Sheet

    Science.gov (United States)

    Mercer, J. L.; Lever, J. H.; Newman, S. D.; Deeb, E. J.; Tracy, B.; Weale, J. C.; Delaney, A. J.; Davies, R.; Emery, K. S.

    2010-12-01

    The Greenland Inland Traverse (GrIT) is an ~740 mile overland resupply effort to transport fuel and cargo from a deep-water port (Thule) to inland research stations (NEEM and Summit). The current route starts at the margin of the Greenland Ice Sheet where the original Thule Take-Off (Camp TUTO) served as a staging area for the traverse to Camp Century during the 1960’s. Crew safety is of utmost importance, and while a short and efficient route is desirable, this area has historically been known to be crevassed and the first ~70 miles have proven to be increasingly dynamic since GrIT’s initial route assessment in 2007. Through a combination of high-resolution satellite imagery analysis, ground penetrating radar (GPR) analysis, route planning and guidance, precise vehicle maneuvering, and mountaineering safety measures, the GrIT’s Strategic Crevasse Avoidance Team (SCAT) has successfully navigated around and documented newly formed crevasses each operational season. Here, we present our methodology for successful navigation, and show the imagery analysis and field assessment by which we’ve discovered increasing numbers and sizes of crevasses and crevasse fields in the ice margin. Half-meter resolution WorldView 1 satellite imagery is taken each August/September to expose crevasses after summer melting has occurred and bridges are sagging or have failed. While it is not possible to determine crevasse widths or bridge depths with this imagery, it does allow identification of most crevasse locations, their lengths and overall crevasse-field size. This provides a roadmap for SCAT to navigate in-and-around crevasse fields. Field measurements show crevasses ranging in size from several centimeters to large chasms tens of meters across. Bridge depths measured in March 2010 ranged from 1.5 meters up to 9 meters. While the data confirm this area is dynamic and rapidly changing, it is difficult to determine whether increased glacial speeds (i.e. surge), a degree of

  13. Measuring picogram per liter concentrations of freely dissolved parent and alkyl PAHs (PAH-34), using passive sampling with polyoxymethylene.

    Science.gov (United States)

    Hawthorne, Steven B; Jonker, Michiel T O; van der Heijden, Stephan A; Grabanski, Carol B; Azzolina, Nicholas A; Miller, David J

    2011-09-01

    Passive sampling with nondepletive sorbents is receiving increasing interest because of its potential to measure freely dissolved concentrations of hydrophobic organic compounds (HOCs) at very low concentrations, as well as its potential for both laboratory use and field deployment. However, consistent approaches have yet to be developed for the majority of HOCs of environmental and regulatory interest. In the present study, a passive sampling method was developed which allows the freely dissolved concentrations of 18 parent and 16 groups of alkyl polycyclic aromatic hydrocarbons (PAHs) on the U.S. Environmental Protection Agency (USEPA)'s "PAH-34" target compound list to be measured. Commercially available 76-μm-thick polyoxymethylene (POM) was placed in sediment/water slurries and exposed for up to 126 days, with 28 days found to be sufficient to obtain equilibrium among the sediment, water, and POM phases for the target 2- to 6-ring PAHs. The POM/water partition coefficients (K(POM)) necessary to calculate freely dissolved concentrations for parent PAHs were determined in two separate laboratories (one using pure standards, and the other using coal tar/petroleum-contaminated sediments) and agreed very well. Since the so-called "16" alkyl PAHs on the PAH-34 list actually include several hundreds of isomers for which no standards exist, sediments impacted by coal tar, or spiked with a coal tar/petroleum nonaqueous phase liquid (NAPL) were also used to measure K(POM) values for each alkyl PAH cluster. The log K(POM) values ranged from ca. 3.0 to 6.2 for 2- to 6-ring parent PAHs, and correlated well with SPARC octanol/water coefficients (K(OW)) (correlation coefficient of r(2) = 0.986). However, log K(POM) values for alkyl PAHs deviated increasingly from SPARC log K(OW) values with increasing degree of alkylation. A simple empirical model that incorporates the number of carbon atoms in a PAH gave a better fit to the experimental log K(POM) values, and was used to

  14. An HDAC2-TET1 switch at distinct chromatin regions significantly promotes the maturation of pre-iPS to iPS cells.

    Science.gov (United States)

    Wei, Tingyi; Chen, Wen; Wang, Xiukun; Zhang, Man; Chen, Jiayu; Zhu, Songcheng; Chen, Long; Yang, Dandan; Wang, Guiying; Jia, Wenwen; Yu, Yangyang; Duan, Tao; Wu, Minjuan; Liu, Houqi; Gao, Shaorong; Kang, Jiuhong

    2015-06-23

    The maturation of induced pluripotent stem cells (iPS) is one of the limiting steps of somatic cell reprogramming, but the underlying mechanism is largely unknown. Here, we reported that knockdown of histone deacetylase 2 (HDAC2) specifically promoted the maturation of iPS cells. Further studies showed that HDAC2 knockdown significantly increased histone acetylation, facilitated TET1 binding and DNA demethylation at the promoters of iPS cell maturation-related genes during the transition of pre-iPS cells to a fully reprogrammed state. We also found that HDAC2 competed with TET1 in the binding of the RbAp46 protein at the promoters of maturation genes and knockdown of TET1 markedly prevented the activation of these genes. Collectively, our data not only demonstrated a novel intrinsic mechanism that the HDAC2-TET1 switch critically regulates iPS cell maturation, but also revealed an underlying mechanism of the interplay between histone acetylation and DNA demethylation in gene regulation. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  15. Analysis of Double Meridian Distance for a Closed Traverse Area towards Developing a Contour Map and Land Title

    Directory of Open Access Journals (Sweden)

    T. U. Ganiron Jr

    2014-07-01

    Full Text Available This research aimed to analyze double meridian distance for a closed traverse area in developing a land title for a propose gymnasium in Qassim University. Theodolite, leveling rod and steel tape plays an important role in measuring elevations, bearings and distances of the boundaries of a lot. Contour map is necessary to determine the traces of level surfaces of successive elevation. This will enable to identify the type of contour map and type of contour lines necessary for this project. Corel draw software is used to draw contour map and guide to interpret the significance of the variables. It is essential to check the error of closure for interior angles and for both latitude and departure before applying the Double Meridian Distance (DMD method to obtain the total area of the lot. Technical descriptions of the land such as distance, bearing, boundaries and area are necessary to visualize the shape & exact location of the land. Developing a land title will be obtained using the technical descriptions of the lot in preparation for the type of gymnasium necessary for Qassim University.

  16. SO 2 flux from Stromboli during the 2007 eruption: Results from the FLAME network and traverse measurements

    Science.gov (United States)

    Burton, M. R.; Caltabiano, T.; Murè, F.; Salerno, G.; Randazzo, D.

    2009-05-01

    SO 2 fluxes emitted by Stromboli during the 27th February-2nd April 2007 effusive eruption were regularly measured both by an automatic network of scanning ultraviolet spectrometers and by traverse measurements conducted by boat and helicopter. The results from both methodologies agree reasonably well, providing a validation for the automatic flux calculations produced by the network. Approximately 22,000 t of SO 2 were degassed during the course of the 35 day eruption at an average rate of 620 t per day. Such a degassing rate is much higher than that normally observed (150-200 t/d), because the cross-sectional area occupied by ascending degassed magma is much greater than normal during the effusion, as descending, degassed magma that would normally occupy a large volume of the conduit is absent. We propose that the hydrostatically controlled magma level within Stromboli's conduit is the main control on eruptive activity, and that a high effusion rate led to the depressurisation of an intermediate magma reservoir, creating a decrease in the magma level until it dropped beneath the eruptive fissure, causing the rapid end of the eruption. A significant decrease in SO 2 flux was observed prior to a paroxysm on 15th March 2007, suggesting that choking of the gas flowing in the conduit may have induced a coalescence event, and consequent rapid ascent of gas and magma that produced the explosion.

  17. Early temporal short-term memory deficits in double transgenic APP/PS1 mice.

    Science.gov (United States)

    Lagadec, Saioa; Rotureau, Lolita; Hémar, Agnès; Macrez, Nathalie; Delcasso, Sebastien; Jeantet, Yannick; Cho, Yoon H

    2012-01-01

    We tested single APP (Tg2576) transgenic, PS1 (PS1dE9) transgenic, and double APP/PS1 transgenic mice at 3 and 6 months of age on the acquisition of a hippocampal-dependent operant "differential reinforcement of low rate schedule" (DRL) paradigm. In this task mice are required to wait for at least 10 seconds (DRL-10s) between 2 consecutive nose poke responses. Our data showed that while single APP and PS1 transgene expression did not affect DRL learning and performance, mice expressing double APP/PS1 transgenes were impaired in the acquisition of DRL-10s at 6 months, but not at 3 months of age. The same impaired double transgenic mice, however, were perfectly capable of normal acquisition of signaled DRL-10s (SDRL-10s) task, a hippocampal-independent task, wherein mice were required to emit responses when the end of the 10-second delay was signaled by a lighting of the chamber. The age-dependent and early deficits of APP/PS1 mice suggest that the appetitive DRL paradigm is sensitive to the amyloid pathology present in double APP/PS1 mice, and that this mouse line represents a good model with which to study the efficacy of therapeutic strategies against Alzheimer's disease. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Reprogramming in vivo produces teratomas and iPS cells with totipotency features.

    Science.gov (United States)

    Abad, María; Mosteiro, Lluc; Pantoja, Cristina; Cañamero, Marta; Rayon, Teresa; Ors, Inmaculada; Graña, Osvaldo; Megías, Diego; Domínguez, Orlando; Martínez, Dolores; Manzanares, Miguel; Ortega, Sagrario; Serrano, Manuel

    2013-10-17

    Reprogramming of adult cells to generate induced pluripotent stem cells (iPS cells) has opened new therapeutic opportunities; however, little is known about the possibility of in vivo reprogramming within tissues. Here we show that transitory induction of the four factors Oct4, Sox2, Klf4 and c-Myc in mice results in teratomas emerging from multiple organs, implying that full reprogramming can occur in vivo. Analyses of the stomach, intestine, pancreas and kidney reveal groups of dedifferentiated cells that express the pluripotency marker NANOG, indicative of in situ reprogramming. By bone marrow transplantation, we demonstrate that haematopoietic cells can also be reprogrammed in vivo. Notably, reprogrammable mice present circulating iPS cells in the blood and, at the transcriptome level, these in vivo generated iPS cells are closer to embryonic stem cells (ES cells) than standard in vitro generated iPS cells. Moreover, in vivo iPS cells efficiently contribute to the trophectoderm lineage, suggesting that they achieve a more plastic or primitive state than ES cells. Finally, intraperitoneal injection of in vivo iPS cells generates embryo-like structures that express embryonic and extraembryonic markers. We conclude that reprogramming in vivo is feasible and confers totipotency features absent in standard iPS or ES cells. These discoveries could be relevant for future applications of reprogramming in regenerative medicine.

  19. Integration-Free iPS Cells Engineered Using Human Artificial Chromosome Vectors

    Science.gov (United States)

    Hiratsuka, Masaharu; Uno, Narumi; Ueda, Kana; Kurosaki, Hajime; Imaoka, Natsuko; Kazuki, Kanako; Ueno, Etsuya; Akakura, Yutaro; Katoh, Motonobu; Osaki, Mitsuhiko; Kazuki, Yasuhiro; Nakagawa, Masato; Yamanaka, Shinya; Oshimura, Mitsuo

    2011-01-01

    Human artificial chromosomes (HACs) have unique characteristics as gene-delivery vectors, including episomal transmission and transfer of multiple, large transgenes. Here, we demonstrate the advantages of HAC vectors for reprogramming mouse embryonic fibroblasts (MEFs) into induced pluripotent stem (iPS) cells. Two HAC vectors (iHAC1 and iHAC2) were constructed. Both carried four reprogramming factors, and iHAC2 also encoded a p53-knockdown cassette. iHAC1 partially reprogrammed MEFs, and iHAC2 efficiently reprogrammed MEFs. Global gene expression patterns showed that the iHACs, unlike other vectors, generated relatively uniform iPS cells. Under non-selecting conditions, we established iHAC-free iPS cells by isolating cells that spontaneously lost iHAC2. Analyses of pluripotent markers, teratomas and chimeras confirmed that these iHAC-free iPS cells were pluripotent. Moreover, iHAC-free iPS cells with a re-introduced HAC encoding Herpes Simplex virus thymidine kinase were eliminated by ganciclovir treatment, indicating that the HAC safeguard system functioned in iPS cells. Thus, the HAC vector could generate uniform, integration-free iPS cells with a built-in safeguard system. PMID:21998730

  20. Inhibition of the integrin signal constitutes a mouse iPS cell niche.

    Science.gov (United States)

    Higuchi, Sayaka; Yoshina, Sawako; Mitani, Shohei

    2016-09-01

    Stem cells are regulated by their surrounding microenvironments, called niche, such as cell-cell interaction and extracellular matrix. Classically, feeder cells as a niche have been used in the culture of iPS cells from both the mouse and the human. However, the regulation mechanism of stem cells by feeder cells as a niche still have been partially unclear. In this study, we used three murine iPS cell lines, iPS-MEF-Ng-20D-17, iPS-MEF-Ng-178B-5 and iPS-MEF-Fb/Ng-440A-3, which were generated by different reprogramming methods. In general, these cell lines commonly need the feeder cells as a niche to culture. Recently, the effect of substrate stiffness is known in stem cell study. First, we focused on the mechanical properties of feeder cells, and then we speculated that feeder-less culture might be made possible by using molecules in place of the mechanical properties of the niche. Finally, we found that the combination of disintegrin (echistatin) and 2i (GSK3 inhibitor and MEK inhibitor) is a sufficient condition for three murine iPS culture. This novel method of mimicking the murine iPS cell niche may be useful to understand signaling pathways to maintain the pluripotency of stem cells. © 2016 The Authors. Development, Growth & Differentiation published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Developmental Biologists.

  1. [Effects of Different Culture Systems on the Hematopoietic Differentiation Ability of iPS Cells].

    Science.gov (United States)

    Fan, Di; He, Wen-Yin; Niu, Xiao-Hua; Ou, Zhan-Hui; Chen, Yu-Chang; Sun, Xiao-Fang

    2016-12-01

    To investigate the in vitro effects of different culture systems on hematopoietic differentiation ability of induced pluripotent stem (iPS) cells. Two culture systems including E8 and mTESR(freeder-free medium), and the classical ES culture medium were chosen for culture of iPS cells. The iPS cells maintaining in above mentioning culcure systems were co-cultured with OP9 cells(murine bone marrow stromal cells) in vitro to be induced to differentiate into hematopoietic stem/progenitor cells. Flow cytometry and real-time quantitative PCR were used to detect the expression of specific hematopoietic markers and the effects of different culture systems on the differentiation of iPS in vitro. iPS cultured in the 3 selected medium could be differentiated into hematopoietic stem cells. Efficiency of hematopoietic differentiation was up to 28.4% in classical ES culture system, which was significantly higher than that in E8 and mTESR system. Under the co-culture with OP9, iPS can differentiate into hematopoietic stem/progenitor cells, which shows higher efficiency when iPS maintained in the ES medium.

  2. A family of small cyclic amphipathic peptides (SCAmpPs) genes in citrus.

    Science.gov (United States)

    Belknap, William R; McCue, Kent F; Harden, Leslie A; Vensel, William H; Bausher, Michael G; Stover, Ed

    2015-04-16

    Citrus represents a crop of global importance both in economic impact and significance to nutrition. Citrus production worldwide is threatened by the disease Huanglongbing (HLB), caused by the phloem-limited pathogen Candidatus Liberibacter spp.. As a source of stable HLB-resistance has yet to be identified, there is considerable interest in characterization of novel disease-associated citrus genes. A gene family of Small Cyclic Amphipathic Peptides (SCAmpPs) in citrus is described. The citrus genomes contain 100-150 SCAmpPs genes, approximately 50 of which are represented in the citrus EST database. These genes encode small ~50 residue precursor proteins that are post-translationally processed, releasing 5-10 residue cyclic peptides. The structures of the SCAmpPs genes are highly conserved, with the small coding domains interrupted by a single intron and relatively extended untranslated regions. Some family members are very highly transcribed in specific citrus tissues, as determined by representation in tissue-specific cDNA libraries. Comparison of the ESTs of related SCAmpPs revealed an unexpected evolutionary profile, consistent with targeted mutagenesis of the predicted cyclic peptide domain. The SCAmpPs genes are displayed in clusters on the citrus chromosomes, with apparent association with receptor leucine-rich repeat protein arrays. This study focused on three SCAmpPs family members with high constitutive expression in citrus phloem. Unexpectedly high sequence conservation was observed in the promoter region of two phloem-expressed SCAmpPs that encode very distinct predicted cyclic products. The processed cyclic product of one of these phloem SCAmpPs was characterized by LC-MS-MS analysis of phloem tissue, revealing properties consistent with a K(+) ionophore. The SCAmpPs amino acid composition, protein structure, expression patterns, evolutionary profile and chromosomal distribution are consistent with designation as ribosomally synthesized defense

  3. Delayed amyloid plaque deposition and behavioral deficits in outcrossed AβPP/PS1 mice.

    Science.gov (United States)

    Couch, Brian A; Kerrisk, Meghan E; Kaufman, Adam C; Nygaard, Haakon B; Strittmatter, Stephen M; Koleske, Anthony J

    2013-04-15

    Alzheimer's disease (AD) is a progressive neurodegenerative dementia characterized by amyloid plaque accumulation, synapse/dendrite loss, and cognitive impairment. Transgenic mice expressing mutant forms of amyloid-β precursor protein (AβPP) and presenilin-1 (PS1) recapitulate several aspects of this disease and provide a useful model system for studying elements of AD progression. AβPP/PS1 mice have been previously shown to exhibit behavioral deficits and amyloid plaque deposition between 4-9 months of age. We crossed AβPP/PS1 animals with mice of a mixed genetic background (C57BL/6 × 129/SvJ) and investigated the development of AD-like features in the resulting outcrossed mice. The onset of memory-based behavioral impairment is delayed considerably in outcrossed AβPP/PS1 mice relative to inbred mice on a C57BL/6 background. While inbred AβPP/PS1 mice develop deficits in radial-arm water maze performance and novel object recognition as early as 8 months, outcrossed AβPP/PS1 mice do not display defects until 18 months. Within the forebrain, we find that inbred AβPP/PS1 mice have significantly higher amyloid plaque burden at 12 months than outcrossed AβPP/PS1 mice of the same age. Surprisingly, inbred AβPP/PS1 mice at 8 months have low plaque burden, suggesting that plaque burden alone cannot explain the accompanying behavioral deficits. Analysis of AβPP processing revealed that elevated levels of soluble Aβ correlate with the degree of behavioral impairment in both strains. Taken together, these findings suggest that animal behavior, amyloid plaque deposition, and AβPP processing are sensitive to genetic differences between mouse strains. Copyright © 2012 Wiley Periodicals, Inc.

  4. Is an off-task mind a freely-moving mind? Examining the relationship between different dimensions of thought.

    Science.gov (United States)

    Mills, Caitlin; Raffaelli, Quentin; Irving, Zachary C; Stan, Dylan; Christoff, Kalina

    2018-02-01

    Mind wandering is frequently defined as task-unrelated or perceptually decoupled thought. However, these definitions may not capture the dynamic features of a wandering mind, such as its tendency to 'move freely'. Here we test the relationship between three theoretically dissociable dimensions of thought: freedom of movement in thought, task-relatedness, and perceptual decoupling (i.e., lack of awareness of surroundings). Using everyday life experience sampling, thought probes were randomly delivered to participants' phones for ten days. Results revealed weak intra-individual correlations between freedom of movement in thought and task-unrelatedness, as well as perceptual decoupling. Within our dataset, over 40% of thoughts would have been misclassified under the assumption that off-task thought is inherently freely moving. Overall, freedom of movement appears to be an independent dimension of thought that is not captured by the two most common measures of mind wandering. Future work focusing on the dynamics of thought may be crucial for improving our understanding of the wandering mind. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Local field potentials in the ventral tegmental area during cocaine-induced locomotor activation: Measurements in freely moving rats.

    Science.gov (United States)

    Harris Bozer, Amber L; Li, Ai-Ling; Sibi, Jiny E; Bobzean, Samara A M; Peng, Yuan B; Perrotti, Linda I

    2016-03-01

    The ventral tegmental area (VTA) has been established as a critical nucleus for processing behavioral changes that occur during psychostimulant use. Although it is known that cocaine induced locomotor activity is initiated in the VTA, not much is known about the electrical activity in real time. The use of our custom-designed wireless module for recording local field potential (LFP) activity provides an opportunity to confirm and identify changes in neuronal activity within the VTA of freely moving rats. The purpose of this study was to investigate the changes in VTA LFP activity in real time that underlie cocaine induced changes in locomotor behavior. Recording electrodes were implanted in the VTA of rats. Locomotor behavior and LFP activity were simultaneously recorded at baseline, and after saline and cocaine injections. Results indicate that cocaine treatment caused increases in both locomotor behavior and LFP activity in the VTA. Specifically, LFP activity was highest during the first 30 min following the cocaine injection and was most robust in Delta and Theta frequency bands; indicating the role of low frequency VTA activity in the initiation of acute stimulant-induced locomotor behavior. Our results suggest that LFP recording in freely moving animals can be used in the future to provide valuable information pertaining to drug induced changes in neural activity. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. A DFT-based toxicity QSAR study of aromatic hydrocarbons to Vibrio fischeri: Consideration of aqueous freely dissolved concentration.

    Science.gov (United States)

    Wang, Ying; Yang, Xianhai; Wang, Juying; Cong, Yi; Mu, Jingli; Jin, Fei

    2016-05-05

    In the present study, quantitative structure-activity relationship (QSAR) techniques based on toxicity mechanism and density functional theory (DFT) descriptors were adopted to develop predictive models for the toxicity of alkylated and parent aromatic hydrocarbons to Vibrio fischeri. The acute toxicity data of 17 aromatic hydrocarbons from both literature and our experimental results were used to construct QSAR models by partial least squares (PLS) analysis. With consideration of the toxicity process, the partition of aromatic hydrocarbons between water phase and lipid phase and their interaction with the target biomolecule, the optimal QSAR model was obtained by introducing aqueous freely dissolved concentration. The high statistical values of R(2) (0.956) and Q(CUM)(2) (0.942) indicated that the model has good goodness-of-fit, robustness and internal predictive power. The average molecular polarizability (α) and several selected thermodynamic parameters reflecting the intermolecular interactions played important roles in the partition of aromatic hydrocarbons between the water phase and biomembrane. Energy of the highest occupied molecular orbital (E(HOMO)) was the most influential descriptor which dominated the toxicity of aromatic hydrocarbons through the electron-transfer reaction with biomolecules. The results demonstrated that the adoption of freely dissolved concentration instead of nominal concentration was a beneficial attempt for toxicity QSAR modeling of hydrophobic organic chemicals. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Psühholoog Parmak: missioonide vahel peaks sõdur aasta puhkama / Merle Parmak ; intervjueerinud Kadri Ibrus

    Index Scriptorium Estoniae

    Parmak, Merle, 1968-

    2009-01-01

    Intervjuu kaitseväe ühendatud õppeasutuste rakendusuuringute keskuse psühholoogiga sõdurite psühholoogilise nõustamise praegusest olukorrast, posttraumaatilisest stressist, missioonidevahelise puhkeperioodi vajalikkusest

  8. Investigation of the pathogenesis of autoimmune diseases by iPS cells.

    Science.gov (United States)

    Natsumoto, Bunki; Shoda, Hirofumi; Fujio, Keishi; Otsu, Makoto; Yamamoto, Kazuhiko

    2017-01-01

    The pluripotent stem cells have a self-renewal ability and can be differentiated into theoretically all of cell types. The induced pluripotent stem (iPS) cells overcame the ethical problems of the human embryonic stem (ES) cell, and enable pathologic analysis of intractable diseases and drug discovery. The in vitro disease model using disease-specific iPS cells enables repeated analyses of human cells without influence of environment factors. Even though autoimmune diseases are polygenic diseases, autoimmune disease-specific iPS cells are thought to be a promising tool for analyzing the pathogenesis of the diseases and drug discovery in future.

  9. File list: DNS.PSC.10.AllAg.iPS_derived_fibroblasts [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.PSC.10.AllAg.iPS_derived_fibroblasts hg19 DNase-seq Pluripotent stem cell iPS derived... fibroblasts http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/DNS.PSC.10.AllAg.iPS_derived_fibroblasts.bed ...

  10. File list: NoD.PSC.05.AllAg.iPS_derived_fibroblasts [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.PSC.05.AllAg.iPS_derived_fibroblasts hg19 No description Pluripotent stem cell iPS derived... fibroblasts http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/NoD.PSC.05.AllAg.iPS_derived_fibroblasts.bed ...

  11. File list: InP.PSC.10.AllAg.iPS_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.PSC.10.AllAg.iPS_derived_neural_cells hg19 Input control Pluripotent stem cell iPS derived... neural cells SRX702550 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.PSC.10.AllAg.iPS_derived_neural_cells.bed ...

  12. File list: Pol.PSC.20.AllAg.iPS_derived_fibroblasts [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.PSC.20.AllAg.iPS_derived_fibroblasts hg19 RNA polymerase Pluripotent stem cell iPS derived... fibroblasts http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Pol.PSC.20.AllAg.iPS_derived_fibroblasts.bed ...

  13. File list: NoD.PSC.50.AllAg.iPS_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.PSC.50.AllAg.iPS_derived_neural_cells hg19 No description Pluripotent stem cell iPS derived... neural cells http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/NoD.PSC.50.AllAg.iPS_derived_neural_cells.bed ...

  14. File list: DNS.PSC.05.AllAg.iPS_derived_fibroblasts [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.PSC.05.AllAg.iPS_derived_fibroblasts hg19 DNase-seq Pluripotent stem cell iPS derived... fibroblasts http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/DNS.PSC.05.AllAg.iPS_derived_fibroblasts.bed ...

  15. File list: Pol.PSC.20.AllAg.iPS_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.PSC.20.AllAg.iPS_derived_neural_cells hg19 RNA polymerase Pluripotent stem cell iPS derived... neural cells http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Pol.PSC.20.AllAg.iPS_derived_neural_cells.bed ...

  16. File list: Pol.PSC.50.AllAg.iPS_derived_fibroblasts [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.PSC.50.AllAg.iPS_derived_fibroblasts hg19 RNA polymerase Pluripotent stem cell iPS derived... fibroblasts http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Pol.PSC.50.AllAg.iPS_derived_fibroblasts.bed ...

  17. File list: InP.PSC.20.AllAg.iPS_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.PSC.20.AllAg.iPS_derived_neural_cells hg19 Input control Pluripotent stem cell iPS derived... neural cells SRX702550 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.PSC.20.AllAg.iPS_derived_neural_cells.bed ...

  18. File list: Oth.PSC.10.AllAg.iPS_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.PSC.10.AllAg.iPS_derived_neural_cells hg19 TFs and others Pluripotent stem cell iPS derived...X968910 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.PSC.10.AllAg.iPS_derived_neural_cells.bed ...

  19. File list: ALL.PSC.10.AllAg.iPS_derived_fibroblasts [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  20. File list: DNS.PSC.20.AllAg.iPS_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DNS.PSC.20.AllAg.iPS_derived_neural_cells hg19 DNase-seq Pluripotent stem cell iPS derived... neural cells http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/DNS.PSC.20.AllAg.iPS_derived_neural_cells.bed ...