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1

The Space Science Group  

NSDL National Science Digital Library

The Space Science Group is part of the Division of Mathematics and Sciences at Northwestern State University in Natchitoches, La. The mission of The Space Science Group is to provide activities that encourage participation in math and science, build knowledge of basic concepts, teach basic science skill, and positively influence attitudes. The mission of The Space Science Group is to develop and implement programs which use aspects of the space program to motivate students to study mathematics and science. Many Space Science Group programs are described at the URL below.

1997-01-01

2

International Space Exploration Coordination Group  

E-print Network

International Space Exploration Coordination Group The Global Exploration Roadmap September 2011, and stimulating technical and commercial innovation. As more nations undertake space exploration activities agencies participating in the International Space Exploration Coordination Group (ISECG) are developing

3

INTERNATIONAL SPACE EXPLORATION COORDINATION GROUP  

E-print Network

1 INTERNATIONAL SPACE EXPLORATION COORDINATION GROUP WORKPLAN Update following 3rd ISECG Meeting space exploration infrastructure standards facilitating interoperability through an international architecture working group. · Continue development of the INTERnational Space Exploration Coordination Tool

4

International Space Exploration Coordination Group  

E-print Network

International Space Exploration Coordination Group The Global Exploration Roadmap September 2011 participating in the International Space Exploration Coordination Group (ISECG) are developing the Global. Agencies agree that human space exploration will be most successful as an international endeavor because

5

International Space Exploration Coordination Group  

E-print Network

International Space Exploration Coordination Group The Global Exploration Roadmap August 2013 #12 The Global Exploration Roadmap is being developed by space agencies participating in the International Space for collaborative space exploration missions beginning with the International Space Station (ISS) and continuing

Rathbun, Julie A.

6

POTENTIAL MEMBERS OF STELLAR KINEMATIC GROUPS WITHIN 30 pc OF THE SUN  

SciTech Connect

We analyze the kinematic histories of stars within 30 pc of the Sun, for which three-dimensional spatial coordinates and three-dimensional velocity vectors are available. From this sample, we extract members of stellar kinematic groups (SKGs) in the following manner. First, we consider in the three-dimensional velocity space centered on the local standard of rest, a sphere with a radius of 8 km s{sup -1} centered on the mean velocity vector of a particular SKG. Around each SKG velocity center, we have found a significant excess of stars compared to background field stars. For each candidate, in the three-dimensional spatial coordinate space, its trajectory is traced back in time by the age of the relevant SKG to obtain the estimated distance from the SKG center at the time of the SKG's birth by the epicyclic approximation and harmonic vertical motion. It often happens that a star is a candidate member of multiple SKGs. Then we rank the candidacy to multiple SKGs based on the smallness of distance separations. In this manner, we have kinematically selected 238 candidates. We further impose at least one of the following qualitative criteria for being a member: spectral type A or B, variability, or EUV and X-ray emission. We have finally selected 137 candidate members of SKGs out of a sample of 966 stars.

Nakajima, Tadashi; Morino, Jun-Ichi, E-mail: tadashi.nakajima@nao.ac.jp [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

2012-01-15

7

POTENTIAL MEMBERS OF STELLAR KINEMATICAL GROUPS WITHIN 20 pc OF THE SUN  

SciTech Connect

We analyze the kinematical histories of stars within 20 pc of the Sun, for which three-dimensional spatial coordinates and three-dimensional velocity vectors are available. From this sample, we extract members of stellar kinematical groups (SKGs) in the following manner. First, in the three-dimensional velocity space centered on the local standard of rest, we consider a sphere with a radius of 8 km s{sup -1} centered on the mean velocity vector of a particular SKG. Around each SKG velocity center, we have found a significant excess of stars compared to background stars. For each candidate, in the three-dimensional spatial coordinate space, its trajectory is traced back in time by the age of the relevant SKG, to estimate the distance from the SKG center at the time of the SKG's birth by the epicycle approximation and vertical harmonic motion. It often happens that a star is a candidate member of multiple SKGs. Then we rank the candidacy to multiple SKGs based on the smallness of distance separations. In this manner, we have kinematically selected 74 candidate members of SKGs out of a sample of 383 stars. If we take into account stellar properties, the number is reduced to 68.

Nakajima, Tadashi; Morino, Jun-Ichi [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Fukagawa, Misato, E-mail: tadashi.nakajima@nao.ac.j [Department of Physics, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan)

2010-09-15

8

Space group Cc: an update.  

PubMed

A recent survey of the Cambridge Structural Database, CSD [Allen (2002). Acta Cryst. B58, 380-388], shows that the percentage of incorrect assignments of the space group Cc has remained at about 10% since the last survey in 1997. PMID:15017100

Marsh, Richard E

2004-04-01

9

UCL DEPARTMENT OF SPACE & CLIMATE PHYSICS SPACE PLASMA PHYSICS GROUP  

E-print Network

UCL DEPARTMENT OF SPACE & CLIMATE PHYSICS SPACE PLASMA PHYSICS GROUP 18th September 2012 STFC 2012 #12;UCL DEPARTMENT OF SPACE & CLIMATE PHYSICS SPACE PLASMA PHYSICS GROUP 18th September 2012 STFC · Conclusion #12;UCL DEPARTMENT OF SPACE & CLIMATE PHYSICS SPACE PLASMA PHYSICS GROUP 18th September 2012 STFC

10

Renormalization group in internal space  

SciTech Connect

Renormalization group in the internal space consists of the gradual change of the coupling constants. Functional evolution equations corresponding to the change of the mass or the coupling constant are presented in the framework of a scalar model. The evolution in the mass which yields the functional generalization of the Callan-Symanzik equation for the one-particle irreducible effective action is given in its renormalized, cutoff-independent form. The evolution of the coupling constant generates an evolution equation for the two-particle irreducible effective action.

Polonyi, J. [Institute for Theoretical Physics, Louis Pasteur University, Strasbourg (France); Department of Atomic Physics, Lorand Eoetvoes University, Budapest (Hungary); Sailer, K. [Department for Theoretical Physics, University of Debrecen, Debrecen (Hungary)

2005-01-15

11

On Hawaiian Groups of Some Topological Spaces  

E-print Network

The paper is devoted to study the structure of Hawaiian groups of some topological spaces. We present some behaviors of Hawaiian groups with respect to product spaces, weak join spaces, cone spaces, covering spaces and locally trivial bundles. In particular, we determine the structure of the $n$-dimensional Hawaiian group of the $m$-dimensional Hawaiian earring space, for all $1\\leq m\\leq n$.

Babaee, Ameneh; Mirebrahimi, Hanieh

2011-01-01

12

UCL DEPARTMENT OF SPACE & CLIMATE PHYSICS SPACE PLASMA PHYSICS GROUP  

E-print Network

Analyser Langmuir probe/ E-field booms Magnetometer LEIA #12;UCL DEPARTMENT OF SPACE & CLIMATE PHYSICSUCL DEPARTMENT OF SPACE & CLIMATE PHYSICS SPACE PLASMA PHYSICS GROUP ESA Lunar Lander ­ L-DEPP C.J. Owen and D.O. Kataria UCL/MSSL #12;UCL DEPARTMENT OF SPACE & CLIMATE PHYSICS SPACE PLASMA PHYSICS GROUP

Anand, Mahesh

13

The trithorax group and Pc group proteins are differentially involved in heterochromatin formation in Drosophila  

Microsoft Academic Search

In Drosophila, the Polycomb group and trithorax group proteins play a critical role in controlling the expression states of homeotic gene\\u000a complexes during development. The common view is that these two classes of proteins bind to the homeotic complexes and regulate\\u000a transcription at the level of chromatin. In the present work, we tested the involvement of both groups in mitotic

Laura Fanti; Barbara Perrini; Lucia Piacentini; Maria Berloco; Enzo Marchetti; Gioacchino Palumbo; Sergio Pimpinelli

2008-01-01

14

IDENTIFYING THE YOUNG LOW-MASS STARS WITHIN 25 pc. II. DISTANCES, KINEMATICS, AND GROUP MEMBERSHIP  

SciTech Connect

We have conducted a kinematic study of 165 young M dwarfs with ages of {approx}<300 Myr. Our sample is composed of stars and brown dwarfs with spectral types ranging from K7 to L0, detected by ROSAT and with photometric distances of {approx}<25 pc assuming that the stars are single and on the main sequence. In order to find stars kinematically linked to known young moving groups (YMGs), we measured radial velocities for the complete sample with Keck and CFHT optical spectroscopy and trigonometric parallaxes for 75 of the M dwarfs with the CAPSCam instrument on the du Pont 2.5 m Telescope. Due to their youthful overluminosity and unresolved binarity, the original photometric distances for our sample underestimated the distances by 70% on average, excluding two extremely young ({approx}<3 Myr) objects found to have distances beyond a few hundred parsecs. We searched for kinematic matches to 14 reported YMGs and identified 10 new members of the AB Dor YMG and 2 of the Ursa Majoris group. Additional possible candidates include six Castor, four Ursa Majoris, two AB Dor members, and one member each of the Her-Lyr and {beta} Pic groups. Our sample also contains 27 young low-mass stars and 4 brown dwarfs with ages {approx}<150 Myr that are not associated with any known YMG. We identified an additional 15 stars that are kinematic matches to one of the YMGs, but the ages from spectroscopic diagnostics and/or the positions on the sky do not match. These warn against grouping stars together based only on kinematics and that a confluence of evidence is required to claim that a group of stars originated from the same star-forming event.

Shkolnik, Evgenya L. [Lowell Observatory, 1400 W. Mars Hill Road, Flagstaff, AZ 86001 (United States); Anglada-Escude, Guillem [Institut fuer Astrophysik, Universitaet Goettingen, Friedrich-Hund-Platz 1, D-37077 Goettingen (Germany); Liu, Michael C.; Bowler, Brendan P. [Institute for Astronomy, University of Hawaii at Manoa 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Weinberger, Alycia J.; Boss, Alan P. [Department of Terrestrial Magnetism, Carnegie Institution for Science, 5241 Broad Branch Road, NW, Washington, DC 20015 (United States); Reid, I. Neill [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Tamura, Motohide, E-mail: shkolnik@lowell.edu [National Astronomical Observatory of Japan, Tokyo (Japan)

2012-10-10

15

On spaces of Kleinian groups  

Microsoft Academic Search

tinuity f2 of G, modulo the ideal boundary of D. The quasiconformal deformation space T(G) is the set of equivalence classes of M(G), and the strong quasiconformal deformation space T(G) is the set of strong equivalence classes. We shall prove that T(G) is a complex analytic manifold (a result previously obtained by Maskit [17], and under some restrictive assumptions by

Irwin Kra

1972-01-01

16

Noncommutative Phase Spaces on Aristotle group  

E-print Network

We realize noncommutative phase spaces as coadjoint orbits of extensions of the Aristotle group in a two-dimensional space. Through these constructions the momenta of the phase spaces do not commute due to the presence of a naturally introduced magnetic field. These cases correspond to the minimal coupling of the momentum with a magnetic potential.

Ancille Ngendakumana; Joachim Nzotungicimpaye; Leonard Todjihounde

2013-07-26

17

The International Space Life Sciences Working Group.  

PubMed

The International Space Life Sciences Working Group (ISLSWG) is made up of representatives from five space agencies: the National Aeronautics and Space Administration (NASA), the European Space Agency (ESA), the Canadian Space Agency (CSA), the Centre National d'Etudes Spatiale (CNES), the Deutsches Zentrum fur Luft- und Raumfahrt (DLR, formerly the Deutsche Agentur fur Raumfahrtangelegenheiten or DARA), and the National Space Development Agency of Japan (NASDA). The group met for the first time in 1989, and since that time has developed a Strategic Plan and has taken concrete steps to implement this plan. The result is a closely coordinated international program of Space Life Sciences which will enable optimal utilization of space flight opportunities. PMID:11542345

Vernikos, J; Ahlf, P R

1998-07-01

18

Guide to Space groups There are only 230 ways (space groups) to describe how identical objects can be  

E-print Network

Guide to Space groups There are only 230 ways (space groups) to describe how identical objects can but it gets better than that! If your structure contains a chrial center then any space group that has a mirror or an inversion operation can be rejected. Of the 230 space groups only 74 space groups

Meagher, Mary

19

Quantum group gauge theory on quantum spaces  

Microsoft Academic Search

We construct quantum group-valued canonical connections on quantum homogeneous spaces, including aq-deformed Dirac monopole on the quantum sphere of Podles with quantum differential structure coming from the 3D calculus of Woronowicz onSUq(2). The construction is presented within the setting of a general theory of quantum principal bundles with quantum group (Hopf algebra) fibre, associated quantum vector bundles and connection one-forms.

Thomasz Brzezinski; Shahn Majid

1993-01-01

20

Latitudinal structure of Pc 5 waves in space: Magnetic and electric field observations  

Microsoft Academic Search

The occurrence frequency and spatial structure of Pc 5 magnetic pulsations in the dawnside of the plasma trough have been studied using data from the Ogo 5 satellite. The wave magnetic fields were obtained from the University of California, Los Angeles, flux-gate magnetometer measurements, and one component of the wave electric field was inferred from oscillations of the ion flux

Howard J. Singer; Margaret G. Kivelson

1979-01-01

21

UK Space Exploration Working Group Report of the  

E-print Network

UK Space Exploration Working Group Report of the UK Space Exploration Working Group 13 September 2007 #12;UK Space Exploration Working Group The UK Space Exploration Working Group Chair: Prof Frank committee to: · review current global plans for space exploration; · assess what opportunities and benefits

Crowther, Paul

22

Optimal space-time constellations from groups  

Microsoft Academic Search

We consider the design of space-time constellations based on group codes for fading channels with multiple transmit and receive antennas. These codes can be viewed as multiantenna extensions of phase-shift keying (PSK), in the sense that all codewords have equal energy, all are rotations of a fixed codeword, and there is a simple differential transmission rule that allows data to

Brian L. Hughes

2003-01-01

23

DYNAMICS OF PLANETCROSSING ASTEROIDS Space Mechanics Group,  

E-print Network

DYNAMICS OF PLANET­CROSSING ASTEROIDS A. MILANI Space Mechanics Group, Department of Mathematics, including Earth­crossing ones. The dynamics of planet­crossing asteroids/comets is strongly con­ trolled in a satisfactory way most of the dynamical behaviors found in the experiments. 1. THE ASTEROID COMPLEX, NEAR EARTH

Milani, Andrea

24

The latitudinal structure of Pc 5 waves in space - Magnetic and electric field observations  

NASA Technical Reports Server (NTRS)

The occurrence frequency and spatial structure of Pc 5 magnetic pulsations in the dawnside of the plasma trough have been studied using data from the Ogo 5 satellite. The wave magnetic fields were obtained from the University of California, Los Angeles, flux-gate magnetometer measurements, and one component of the wave electric field was inferred from oscillations of the ion flux measured by the Lockheed light ion mass spectrometer. During portions of seven of the 19 passes comprising the survey, Pc 5 oscillations were observed in the ion flux but not in the magnetic field, and in each case the satellite was within 10 deg of the geomagnetic equator. Above 10 deg latitude, transverse magnetic and electric oscillations were both observed. The results are consistent with the model of a standing Alfven wave along a resonant field line with the geomagnetic equator as a node of the magnetic perturbation, that is, an odd mode.

Singer, H. J.; Kivelson, M. G.

1979-01-01

25

Long-range repression by multiple polycomb group (PcG) proteins targeted by fusion to a defined DNA-binding domain in Drosophila.  

PubMed Central

A tethering assay was developed to study the effects of Polycomb group (PcG) proteins on gene expression in vivo. This system employed the Su(Hw) DNA-binding domain (ZnF) to direct PcG proteins to transposons that carried the white and yellow reporter genes. These reporters constituted naive sensors of PcG effects, as bona fide PcG response elements (PREs) were absent from the constructs. To assess the effects of different genomic environments, reporter transposons integrated at nearly 40 chromosomal sites were analyzed. Three PcG fusion proteins, ZnF-PC, ZnF-SCM, and ZnF-ESC, were studied, since biochemical analyses place these PcG proteins in distinct complexes. Tethered ZnF-PcG proteins repressed white and yellow expression at the majority of sites tested, with each fusion protein displaying a characteristic degree of silencing. Repression by ZnF-PC was stronger than ZnF-SCM, which was stronger than ZnF-ESC, as judged by the percentage of insertion lines affected and the magnitude of the conferred repression. ZnF-PcG repression was more effective at centric and telomeric reporter insertion sites, as compared to euchromatic sites. ZnF-PcG proteins tethered as far as 3.0 kb away from the target promoter produced silencing, indicating that these effects were long range. Repression by ZnF-SCM required a protein interaction domain, the SPM domain, which suggests that this domain is not primarily used to direct SCM to chromosomal loci. This targeting system is useful for studying protein domains and mechanisms involved in PcG repression in vivo. PMID:11333237

Roseman, R R; Morgan, K; Mallin, D R; Roberson, R; Parnell, T J; Bornemann, D J; Simon, J A; Geyer, P K

2001-01-01

26

NASA's Internal Space Weather Working Group  

NASA Technical Reports Server (NTRS)

Measurements from many of NASA's scientific spacecraft are used routinely by space weather forecasters, both in the U.S. and internationally. ACE, SOHO (an ESA/NASA collaboration), STEREO, and SDO provide images and in situ measurements that are assimilated into models and cited in alerts and warnings. A number of years ago, the Space Weather laboratory was established at NASA-Goddard, along with the Community Coordinated Modeling Center. Within that organization, a space weather service center has begun issuing alerts for NASA's operational users. NASA's operational user community includes flight operations for human and robotic explorers; atmospheric drag concerns for low-Earth orbit; interplanetary navigation and communication; and the fleet of unmanned aerial vehicles, high altitude aircraft, and launch vehicles. Over the past three years we have identified internal stakeholders within NASA and formed a Working Group to better coordinate their expertise and their needs. In this presentation we will describe this activity and some of the challenges in forming a diverse working group.

St. Cyr, O. C.; Guhathakurta, M.; Bell, H.; Niemeyer, L.; Allen, J.

2011-01-01

27

Cell Groups Reveal Structure of Stimulus Space  

PubMed Central

An important task of the brain is to represent the outside world. It is unclear how the brain may do this, however, as it can only rely on neural responses and has no independent access to external stimuli in order to “decode” what those responses mean. We investigate what can be learned about a space of stimuli using only the action potentials (spikes) of cells with stereotyped—but unknown—receptive fields. Using hippocampal place cells as a model system, we show that one can (1) extract global features of the environment and (2) construct an accurate representation of space, up to an overall scale factor, that can be used to track the animal's position. Unlike previous approaches to reconstructing position from place cell activity, this information is derived without knowing place fields or any other functions relating neural responses to position. We find that simply knowing which groups of cells fire together reveals a surprising amount of structure in the underlying stimulus space; this may enable the brain to construct its own internal representations. PMID:18974826

2008-01-01

28

TOPOLOGICAL SPACES AND THE FUNDAMENTAL GROUP MAXWELL XIONG  

E-print Network

TOPOLOGICAL SPACES AND THE FUNDAMENTAL GROUP MAXWELL XIONG Abstract. This paper provides a basic as a topological space, and what open 1 #12;2 MAXWELL XIONG and closed sets look like within those spaces. We

May, J. Peter

29

UCLA IGPP Space Plasma Simulation Group  

NASA Technical Reports Server (NTRS)

During the past 10 years the UCLA IGPP Space Plasma Simulation Group has pursued its theoretical effort to develop a Mission Oriented Theory (MOT) for the International Solar Terrestrial Physics (ISTP) program. This effort has been based on a combination of approaches: analytical theory, large scale kinetic (LSK) calculations, global magnetohydrodynamic (MHD) simulations and self-consistent plasma kinetic (SCK) simulations. These models have been used to formulate a global interpretation of local measurements made by the ISTP spacecraft. The regions of applications of the MOT cover most of the magnetosphere: the solar wind, the low- and high-latitude magnetospheric boundary, the near-Earth and distant magnetotail, and the auroral region. Most recent investigations include: plasma processes in the electron foreshock, response of the magnetospheric cusp, particle entry in the magnetosphere, sources of observed distribution functions in the magnetotail, transport of oxygen ions, self-consistent evolution of the magnetotail, substorm studies, effects of explosive reconnection, and auroral acceleration simulations.

1998-01-01

30

Actuator grouping optimization on flexible space reflectors  

NASA Astrophysics Data System (ADS)

With the rapid advances in deployable membrane and mesh antenna technologies, the feasibility of developing large, lightweight reflectors has greatly improved. In order to achieve the required accuracy, precision surface control is needed on these lightweight reflectors. While studies have shown that domain control of space reflectors via Polyvinylidene Fluoride (PVDF) actuators is promising, the challenge is to realistically control a large number of distributed actuators with limited number of power supplies. In this research, a new En Mass Elimination method is synthesized to determine the optimal grouping of actuators when the actuator number exceeds the number of power supplies available. An analytical model is developed and the methodology is demonstrated numerically through system simulation on the derived model.

Hill, Jeffrey R.; Wang, K. W.; Fang, Houfei; Quijano, Ubaldo

2011-03-01

31

International Space Station Earth Observations Working Group  

NASA Technical Reports Server (NTRS)

The multilateral Earth Observations Working Group (EOWG) was chartered in May 2012 in order to improve coordination and collaboration of Earth observing payloads, research, and applications on the International Space Station (ISS). The EOWG derives its authority from the ISS Program Science Forum, and a NASA representative serves as a permanent co-chair. A rotating co-chair position can be occupied by any of the international partners, following concurrence by the other partners; a JAXA representative is the current co-chair. Primary functions of the EOWG include, 1) the exchange of information on plans for payloads, from science and application objectives to instrument development, data collection, distribution and research; 2) recognition and facilitation of opportunities for international collaboration in order to optimize benefits from different instruments; and 3) provide a formal ISS Program interface for collection and application of remotely sensed data collected in response to natural disasters through the International Charter, Space and Major Disasters. Recent examples of EOWG activities include coordination of bilateral data sharing protocols between NASA and TsNIIMash for use of crew time and instruments in support of ATV5 reentry imaging activities; discussion of continued use and support of the Nightpod camera mount system by NASA and ESA; and review and revision of international partner contributions on Earth observations to the ISS Program Benefits to Humanity publication.

Stefanov, William L.; Oikawa, Koki

2015-01-01

32

An IBM PC-based math model for space station solar array simulation  

NASA Technical Reports Server (NTRS)

This report discusses and documents the design, development, and verification of a microcomputer-based solar cell math model for simulating the Space Station's solar array Initial Operational Capability (IOC) reference configuration. The array model is developed utilizing a linear solar cell dc math model requiring only five input parameters: short circuit current, open circuit voltage, maximum power voltage, maximum power current, and orbit inclination. The accuracy of this model is investigated using actual solar array on orbit electrical data derived from the Solar Array Flight Experiment/Dynamic Augmentation Experiment (SAFE/DAE), conducted during the STS-41D mission. This simulator provides real-time simulated performance data during the steady state portion of the Space Station orbit (i.e., array fully exposed to sunlight). Eclipse to sunlight transients and shadowing effects are not included in the analysis, but are discussed briefly. Integrating the Solar Array Simulator (SAS) into the Power Management and Distribution (PMAD) subsystem is also discussed.

Emanuel, E. M.

1986-01-01

33

PC Software graphics tool for conceptual design of space/planetary electrical power systems  

NASA Technical Reports Server (NTRS)

This paper describes the Decision Support System (DSS), a personal computer software graphics tool for designing conceptual space and/or planetary electrical power systems. By using the DSS, users can obtain desirable system design and operating parameters, such as system weight, electrical distribution efficiency, and bus power. With this tool, a large-scale specific power system was designed in a matter of days. It is an excellent tool to help designers make tradeoffs between system components, hardware architectures, and operation parameters in the early stages of the design cycle. The DSS is a user-friendly, menu-driven tool with online help and a custom graphical user interface. An example design and results are illustrated for a typical space power system with multiple types of power sources, frequencies, energy storage systems, and loads.

Truong, Long V.

1995-01-01

34

Nature GeNetics VOLUME 46 | NUMBER 9 | SEPTEMBER 2014 973 The Polycomb (PcG) and Trithorax Group (TrxG) proteins are essen-  

E-print Network

Nature GeNetics VOLUME 46 | NUMBER 9 | SEPTEMBER 2014 973 The Polycomb (PcG) and Trithorax Group of a Polycomb/Trithorax response element Veronika A Herzog1,7, Adelheid Lempradl1,2,7, Johanna Trupke1, Helena (TrxG) proteins are essen- tial for development and differentiation in flies and vertebrates1. In flies

Kaski, Samuel

35

Space Telescope Imaging Spectrograph Spectroscopy of the Central 14 pc OF NGC 3998: Evidence for an Inflow  

NASA Astrophysics Data System (ADS)

Prior imaging of the lenticular galaxy, NGC 3998, with the Hubble Space Telescope revealed a small, highly inclined, nuclear ionized gas disk, the kinematics of which indicate the presence of a 270 million solar mass black hole. Plausible kinematic models are used to constrain the size of the broad emission line region (BELR) in NGC 3998 by modeling the shape of the broad H?, H?, and H? emission line profiles. The analysis indicates that the BELR is large with an outer radius ~7 pc, regardless of whether the kinematic model is represented by an accretion disk or a spherically symmetric inflow. The electron temperature in the BELR is <= 28,800 K consistent with photoionization by the active galactic nucleus (AGN). Indeed, the AGN is able to sustain the ionization of the BELR, albeit with a high covering factor ranging between 20% and 100% depending on the spectral energy distribution adopted for the AGN. The high covering factor favors a spherical distribution for the gas as opposed to a thin disk. If the gas density is >=7 × 103 cm-3 as indicated by the broad forbidden [S II] emission line ratio, then interpreting the broad H? emission line in terms of a steady state spherically symmetric inflow leads to a rate <= 6.5 × 10-2 M sun yr-1 which exceeds the inflow requirement to explain the X-ray luminosity in terms of a radiatively inefficient inflow by a factor of <=18.

Devereux, Nick

2011-02-01

36

Space station group activities habitability module study  

NASA Technical Reports Server (NTRS)

This study explores and analyzes architectural design approaches for the interior of the Space Station Habitability Module (originally defined as Habitability Module 1 in Space Station Reference Configuration Decription, JSC-19989, August 1984). In the Research Phase, architectural program and habitability design guidelines are specified. In the Schematic Design Phase, a range of alternative concepts is described and illustrated with drawings, scale-model photographs and design analysis evaluations. Recommendations are presented on the internal architectural, configuration of the Space Station Habitability Module for such functions as the wardroom, galley, exercise facility, library and station control work station. The models show full design configurations for on-orbit performance.

Nixon, David

1986-01-01

37

The CPT Group in the de Sitter Space  

E-print Network

$P$-, $T$-, $C$-transformations of the Dirac field in the de Sitter space are studied in the framework of an automorphism set of Clifford algebras. Finite group structure of the discrete transformations is elucidated. It is shown that $CPT$ groups of the Dirac field in Minkowski and de Sitter spaces are isomorphic.

V. V. Varlamov

2005-08-18

38

1 WJL WJL 3/14/00 revised PC dimensions, requiring LV panels to go to space in a second rack REQUIRED SIGNATURES, DATE  

E-print Network

1 WJL WJL 3/14/00 revised PC dimensions, requiring LV panels to go to space in a second rack INCHES ALL DIMENSIONS ARE TOFp DRAWING NUMBER REV. DATE DATE W.J. Llope 1/26/00 DRWN BY TOFp Rack NUMBER REV. DATECOGNIZANT ENG PRODUCTION APP TOFp/pVPD Rack1 Contents 5U Breaker Panel 15U SM255 Mount

Llope, William J.

39

Exceptional groups, symmetric spaces and applications  

SciTech Connect

In this article we provide a detailed description of a technique to obtain a simple parameterization for different exceptional Lie groups, such as G{sub 2}, F{sub 4} and E{sub 6}, based on their fibration structure. For the compact case, we construct a realization which is a generalization of the Euler angles for SU(2), while for the non compact version of G{sub 2(2)}/SO(4) we compute the Iwasawa decomposition. This allows us to obtain not only an explicit expression for the Haar measure on the group manifold, but also for the cosets G{sub 2}/SO(4), G{sub 2}/SU(3), F{sub 4}/Spin(9), E{sub 6}/F{sub 4} and G{sub 2(2)}/SO(4) that we used to find the concrete realization of the general element of the group. Moreover, as a by-product, in the simplest case of G{sub 2}/SO(4), we have been able to compute an Einstein metric and the vielbein. The relevance of these results in physics is discussed.

Cerchiai, Bianca L.; Cacciatori, Sergio L.

2009-03-31

40

Actuator Grouping Optimization on Flexible Space Reflectors  

NASA Technical Reports Server (NTRS)

With the rapid advances in deployable membrane and mesh antenna technologies, the feasibility of developing large, lightweight reflectors has greatly improved. In order to achieve the required surface accuracy, precision surface control is needed on these lightweight reflectors. For this study, an analytical model is shown which combines a flexible Kapton reflector with Polyvinylidene fluoride (PVDF) actuators for surface control. Surface errors are introduced that are similar to real world scenarios, and a least squares control algorithm is developed for surface control. Experimental results on a 2.4 meter reflector show that while the analytical reflector model is generally correct, due to idiosyncrasies in the reflector it cannot be used for online control. A new method called the En Mass Elimination algorithm is used to determine the optimal grouping of actuators when the number of actuators in the system exceeds the number of power supplies available.

Hill, Jeffrey R.; Wang, K. W.; Fang, Houfei; Quijano, Ubaldo

2011-01-01

41

Group theoretical construction of planar noncommutative phase spaces  

SciTech Connect

Noncommutative phase spaces are generated and classified in the framework of centrally extended anisotropic planar kinematical Lie groups as well as in the framework of noncentrally abelian extended planar absolute time Lie groups. Through these constructions the coordinates of the phase spaces do not commute due to the presence of naturally introduced fields giving rise to minimal couplings. By symplectic realizations methods, physical interpretations of generators coming from the obtained structures are given.

Ngendakumana, Ancille, E-mail: nancille@yahoo.fr; Todjihoundé, Leonard, E-mail: leonardt@imsp.uac.org [Institut de Mathématiques et des Sciences Physiques (IMSP), Porto-Novo (Benin)] [Institut de Mathématiques et des Sciences Physiques (IMSP), Porto-Novo (Benin); Nzotungicimpaye, Joachim, E-mail: kimpaye@kie.ac.rw [Kigali Institute of Education (KIE), Kigali (Rwanda)] [Kigali Institute of Education (KIE), Kigali (Rwanda)

2014-01-15

42

Drosophila O-GlcNAc transferase (OGT) is encoded by the Polycomb group (PcG) gene, super sex combs (sxc).  

PubMed

O-linked N-acetylglucosamine transferase (OGT) reversibly modifies serine and threonine residues of many intracellular proteins with a single beta-O-linked N-acetylglucosamine residue (O-GlcNAc), and has been implicated in insulin signaling, neurodegenerative disease, cellular stress response, and other important processes in mammals. OGT also glycosylates RNA polymerase II and various transcription factors, which suggests that it might be directly involved in transcriptional regulation. We report here that the Drosophila OGT is encoded by the Polycomb group (PcG) gene, super sex combs (sxc). Furthermore, major sites of O-GlcNAc modification on polytene chromosomes correspond to PcG protein binding sites. Our results thus suggest a direct role for O-linked glycosylation by OGT in PcG-mediated epigenetic gene silencing, which is important in developmental regulation, stem cell maintenance, genomic imprinting, and cancer. In addition, we observe rescue of sxc lethality by a human Ogt cDNA transgene; thus Drosophila may provide an ideal model to study important functional roles of OGT in mammals. PMID:19666537

Sinclair, Donald A R; Syrzycka, Monika; Macauley, Matthew S; Rastgardani, Tara; Komljenovic, Ivana; Vocadlo, David J; Brock, Hugh W; Honda, Barry M

2009-08-11

43

SHELXT – Integrated space-group and crystal-structure determination  

PubMed Central

The new computer program SHELXT employs a novel dual-space algorithm to solve the phase problem for single-crystal reflection data expanded to the space group P1. Missing data are taken into account and the resolution extended if necessary. All space groups in the specified Laue group are tested to find which are consistent with the P1 phases. After applying the resulting origin shifts and space-group symmetry, the solutions are subject to further dual-space recycling followed by a peak search and summation of the electron density around each peak. Elements are assigned to give the best fit to the integrated peak densities and if necessary additional elements are considered. An isotropic refinement is followed for non-centrosymmetric space groups by the calculation of a Flack parameter and, if appropriate, inversion of the structure. The structure is assembled to maximize its connectivity and centred optimally in the unit cell. SHELXT has already solved many thousand structures with a high success rate, and is optimized for multiprocessor computers. It is, however, unsuitable for severely disordered and twinned structures because it is based on the assumption that the structure consists of atoms. PMID:25537383

Sheldrick, George M.

2015-01-01

44

The space shuttle payload planning working groups. Volume 2: Atmospheric and space physics  

NASA Technical Reports Server (NTRS)

The findings of the Atmospheric and Space Physics working group of the space shuttle mission planning activity are presented. The principal objectives defined by the group are: (1) to investigate the detailed mechanisms which control the near-space environment of the earth, (2) to perform plasma physics investigations not feasible in ground-based laboratories, and (3) to conduct investigations which are important in understanding planetary and cometary phenomena. The core instrumentation and laboratory configurations for conducting the investigations are defined.

1973-01-01

45

The space shuttle payload planning working groups. Volume 10: Space technology  

NASA Technical Reports Server (NTRS)

The findings and recommendations of the Space Technology group of the space shuttle payload planning activity are presented. The elements of the space technology program are: (1) long duration exposure facility, (2) advanced technology laboratory, (3) physics and chemistry laboratory, (4) contamination experiments, and (5) laser information/data transmission technology. The space technology mission model is presented in tabular form. The proposed experiments to be conducted by each test facility are described. Recommended approaches for user community interfacing are included.

1973-01-01

46

Small-Bias Spaces for Group Products and David Zuckerman  

E-print Network

Small-Bias Spaces for Group Products Raghu Meka and David Zuckerman Department of Computer Science for width w ROPBPs are equivalent to functions P : {0, 1}r {0, 1}n that fool products of group elements and g P(y)1 1 g P(y)2 2 . . . g P(y)n n with y u {0, 1}r are -close in variation distance (for a multi

Zuckerman, David

47

Entanglement renormalization in free bosonic systems: real-space versus momentum-space renormalization group transforms  

E-print Network

The ability of entanglement renormalization (ER) to generate a proper real-space renormalization group (RG) flow in extended quantum systems is analysed in the setting of harmonic lattice systems in D=1 and D=2 spatial dimensions. A conceptual overview of the steps involved in momentum-space RG is provided and contrasted against the equivalent steps in the real-space setting. The real-space RG flow, as generated by ER, is compared against the exact results from momentum-space RG, including an investigation of a critical fixed point and the effect of relevant and irrelevant perturbations.

G. Evenbly; G. Vidal

2010-03-05

48

The Logic of Rotations Lie Groups and Homogeneous Spaces  

E-print Network

The Logic of Rotations Lie Groups and Homogeneous Spaces Jean Gallier CIS Department University(e.~ke, I OJ¥' q cat Figure: Dog Logic Jean Gallier (Upenn) The Logic of Rotations December 3, 2013 2 / 31 #12;Jean Gallier (Upenn) The Logic of Rotations December 3, 2013 3 / 31 #12;Jean Gallier (Upenn

Gallier, Jean

49

CONFIGURATION SPACES AND BRAID GROUPS ON GRAPHS IN ROBOTICS  

E-print Network

CONFIGURATION SPACES AND BRAID GROUPS ON GRAPHS IN ROBOTICS ROBERT GHRIST School of Mathematics control schemes for Automated Guided Vehicles (robots) in industrial settings. In this announcement, we filtered through the robotics community [Lat91, KR90]. Surprisingly, topologists have been generally

Ghrist, Robert W.

50

Symmetry and Space Groups Space groups arranged in order of frequency in the Cambridge Crystallographic Data Base.  

E-print Network

) = I(k, -h, l) Unique Intensity Data Set : 1/8 hemisphere 0 h ; 0 k; 0 l Class Space Groups 4 P41 P43 P4 P42 I41 I4 -4 P -4 I -4 2/m P42/n P4/n P42/m P4/m I4/m I41/a Laue Group : 4/mmm Tetragonal Cell

Meagher, Mary

51

On Topological Homotopy Groups of $n$-Hawaiian like spaces  

E-print Network

By an $n$-Hawaiian like space $X$ we mean the natural inverse limit, $\\displaystyle{\\varprojlim (Y_i^{(n)},y_i^*)}$, where $(Y_i^{(n)},y_i^*)=\\bigvee_{j\\leq i}(X_j^{(n)},x_j^*)$ is the wedge of $X_j^{(n)}$'s in which $X_j^{(n)}$'s are $(n-1)$-connected, locally $(n-1)$-connected, $n$-semilocally simply connected and compact CW spaces. In this paper, first we show that the natural homomorphism $\\displaystyle{\\beta_n:\\pi_n(X,*)\\rightarrow \\varprojlim \\pi_n(Y_i^{(n)},y_i^*)}$ is bijection. Second, using this fact we prove that the topological $n$-homotopy group of an $n$-Hawaiian like space, $\\pi_n^{top}(X,x^*)$, is a topological group for all $n\\geq 2$ which is a partial answer to the open question whether $\\pi_n^{top}(X,x^*)$ is a topological group for any space $X$ and $n\\geq 1$. Moreover, we show that $\\pi_n^{top}(X,x^*)$ is metrizable.

Ghane, Fateme Helen; Mashayekhy, Behrooz; Mirebrahimi, Hanieh

2010-01-01

52

Gaussian distributions, Jacobi group, and Siegel-Jacobi space  

NASA Astrophysics Data System (ADS)

Let N be the space of Gaussian distribution functions over ?, regarded as a 2-dimensional statistical manifold parameterized by the mean ? and the deviation ?. In this paper, we show that the tangent bundle of N , endowed with its natural Kähler structure, is the Siegel-Jacobi space appearing in the context of Number Theory and Jacobi forms. Geometrical aspects of the Siegel-Jacobi space are discussed in detail (completeness, curvature, group of holomorphic isometries, space of Kähler functions, and relationship to the Jacobi group), and are related to the quantum formalism in its geometrical form, i.e., based on the Kähler structure of the complex projective space. This paper is a continuation of our previous work [M. Molitor, "Remarks on the statistical origin of the geometrical formulation of quantum mechanics," Int. J. Geom. Methods Mod. Phys. 9(3), 1220001, 9 (2012); M. Molitor, "Information geometry and the hydrodynamical formulation of quantum mechanics," e-print arXiv (2012); M. Molitor, "Exponential families, Kähler geometry and quantum mechanics," J. Geom. Phys. 70, 54-80 (2013)], where we studied the quantum formalism from a geometric and information-theoretical point of view.

Molitor, Mathieu

2014-12-01

53

The space shuttle payload planning working groups: Volume 9: Materials processing and space manufacturing  

NASA Technical Reports Server (NTRS)

The findings and recommendations of the Materials Processing and Space Manufacturing group of the space shuttle payload planning activity are presented. The effects of weightlessness on the levitation processes, mixture stability, and control over heat and mass transport in fluids are considered for investigation. The research and development projects include: (1) metallurgical processes, (2) electronic materials, (3) biological applications, and (4)nonmetallic materials and processes. Additional recommendations are provided concerning the allocation of payload space, acceptance of experiments for flight, flight qualification, and private use of the space shuttle.

1973-01-01

54

The Lorentzian oscillator group as a geodesic orbit space  

SciTech Connect

We prove that the four-dimensional oscillator group Os, endowed with any of its usual left-invariant Lorentzian metrics, is a Lorentzian geodesic (so, in particular, null-geodesic) orbit space with some of its homogeneous descriptions corresponding to certain homogeneous Lorentzian structures. Each time that Os is endowed with a suitable metric and an appropriate homogeneous Lorentzian structure, it is a candidate for constructing solutions in d-dimensional supergravity with at least 24 of the 32 possible supersymmetries.

Batat, W. [Ecole Normale Superieure d'Enseignement Technologique d'Oran, Departement de Mathematiques et Informatique, B.P. 1523, El M'Naouar, Oran (Algeria); Gadea, P. M. [Instituto de Fisica Fundamental, CSIC, Serrano 113-bis, 28006 Madrid (Spain); Oubina, J. A. [Departamento de Xeometria e Topoloxia, Facultade de Matematicas, Universidade de Santiago de Compostela, 15782 Santiago de Compostela (Spain)

2012-10-15

55

National facilities study. Volume 4: Space operations facilities task group  

NASA Technical Reports Server (NTRS)

The principal objectives of the National Facilities Study (NFS) were to: (1) determine where U.S. facilities do not meet national aerospace needs; (2) define new facilities required to make U.S. capabilities 'world class' where such improvements are in the national interest; (3) define where consolidation and phase-out of existing facilities is appropriate; and (4) develop a long-term national plan for world-class facility acquisition and shared usage. The Space Operations Facilities Task Group defined discrete tasks to accomplish the above objectives within the scope of the study. An assessment of national space operations facilities was conducted to determine the nation's capability to meet the requirements of space operations during the next 30 years. The mission model used in the study to define facility requirements is described in Volume 3. Based on this model, the major focus of the Task Group was to identify any substantive overlap or underutilization of space operations facilities and to identify any facility shortfalls that would necessitate facility upgrades or new facilities. The focus of this initial study was directed toward facility recommendations related to consolidations, closures, enhancements, and upgrades considered necessary to efficiently and effectively support the baseline requirements model. Activities related to identifying facility needs or recommendations for enhancing U.S. international competitiveness and achieving world-class capability, where appropriate, were deferred to a subsequent study phase.

1994-01-01

56

Space station group activities habitability module study: A synopsis  

NASA Technical Reports Server (NTRS)

Space station habitability was studied by investigating crew activity routines, proximities, ergonomic envelopes, and group volumes. Ten alternative schematic interior designs were proposed. Preliminary conclusions include: (1) in-service interior modifications may be necessary and should be planned for; (2) design complexity will be increased if the module cluster is reduced from five to three; (3) the increased crew circulation attendant upon enhancement of space station activity may produce human traffic bottlenecks and should be planned for; (4) a single- or two-person quiet area may be desirable to provide crew members with needed solitude during waking hours; and (5) the decision to choose a two-shift or three-shift daily cycle will have a significant impact on the design configuration and operational efficiency of the human habitat.

Nixon, David; Glassman, Terry

1987-01-01

57

Quantum Circuit Synthesis using Group Decomposition and Hilbert Spaces  

NASA Astrophysics Data System (ADS)

The exponential nature of Moore's law has inadvertently created huge data storage complexes that are scattered around the world. Data elements are continuously being searched, processed, erased, combined and transferred to other storage units without much regard to power consumption. The need for faster searches and power efficient data processing is becoming a fundamental requirement. Quantum computing may offer an elegant solution to speed and power through the utilization of the natural laws of quantum mechanics. Therefore, minimal cost quantum circuit implementation methodologies are greatly desired. This thesis explores the decomposition of group functions and the Walsh spectrum for implementing quantum canonical cascades with minimal cost. Three different methodologies, using group decomposition, are presented and generalized to take advantage of different quantum computing hardware, such as ion traps and quantum dots. Quantum square root of swap gates and fixed angle rotation gates comprise the first two methodologies. The third and final methodology provides further quantum cost reduction by more efficiently utilizing Hilbert spaces through variable angle rotation gates. The thesis then extends the methodology to realize a robust quantum circuit synthesis tool for single and multi-output quantum logic functions.

Saraivanov, Michael S.

58

REQUEST FOR LEASED SPACE 3. FROM: (REQUESTING DIVISION) 4. FOR: (USER GROUP)  

E-print Network

) 1. No. of Employee Spaces 2. No. of Visitor Spaces SIGNATURE (DIVISION HEAD) 3. No. of OfficialREQUEST FOR LEASED SPACE 1. DATE 2. TO: 3. FROM: (REQUESTING DIVISION) 4. FOR: (USER GROUP) CONTACT. SPACE REQUIREMENTS INITIAL EXPANSION REPLACEMENT TYPE OF SPACE NO. OF PERSONNEL SQ. FT. PER PERSON SQ

59

Space Weather Activities of IONOLAB Group: IONOLAB-TEC  

NASA Astrophysics Data System (ADS)

Space Weather (SW) is the concept of changing environmental conditions in outer space and affect Earth and its technological systems. SW is a consequence of the solar activities and the coupling of solar energy on Earth's atmosphere due to the Earth's magnetic field. The monitoring and prediction of SW has utmost importance for HF communication, Satellite communication, navigation and guidance systems, Low Earth Orbit (LEO) satellite systems, Space Craft exit and entry into the atmosphere. Ionosphere is the plasma layer of the atmosphere that is ionized by solar radiation and it is a key player of SW. Ionosphere is a temporally and spatially varying, dispersive, anisotropic and inhomogeneous medium that is characterized primarily by its electron density distribution. IONOLAB is a group of researchers of various disciplines, getting together to handle challenges of the Earth's ionosphere. The team has researchers from Hacettepe University and Bilkent University, Department of Electrical and Electronics Engineering and General Command of Mapping of Turkish Army. One of the most important contributions of IONOLAB group is the automated web-based computation service for Total Electron Content (TEC). TEC corresponds to the line integral of electron density distribution on a given path. TEC can also be expressed as the amount of free electrons within 1 m2 cross-sectional area of the cylinder on the ray path. Global Position System (GPS) provides a cost-effective medium for monitoring of ionosphere using the signals recorded by stationary GPS receivers in estimating TEC. IONOLAB group has developed IONOLAB-TEC for reliable and robust estimates for all latitudes and both calm and disturbed days by using RINEX, IONEX and satellite ephemeris data provided from the IGS centers. IONOLAB-TEC consists of a regularized signal estimation algorithm which combines signals from all GPS satellites for a given instant and a given receiver, for a desired time period or for 24 hours, with 30 s time resolution. IONOLAB-TEC values also include the receiver differential code bias (DCB) for each GPS station estimated uniquely by the IONOLAB-BIAS algorithm. The web based computation program is written in JAVA and it is provided both in Turkish and English at www.ionolab.org. The IONOLAB-TEC computation requires no installation or licensing on the client side. The application has a layered design. Developed components are modular that allows possible changes regarding the estimation method can be easily adapted. Same flexibility is also provided for the data access. Also, presentation of estimation data is architected to support different client types. Currently, the user can login to the IONOLAB-TEC web site and choose the desired location and dates on-line for TEC estimation. The carrier phase leveled TEC estimates of IONOLAB-TEC are provided for the chosen station/s and for the chosen day/s along with two-hourly GIM-TEC estimates of IGS centers. The output is provided in the user designated form either in graphs or an excel data sheet. The IONOLAB-TEC provides robust, reliable, and high resolution TEC estimates and provides a medium for comparison of the GIM-TEC values from the IGS centers.

Arikan, F.; Sezen, U.; Arikan, O.; Ugurlu, O.; Nayir, H.

2009-04-01

60

Urban space as a large-scale group playground Tech Report kmi-04-24  

E-print Network

behaviour and playful group interaction in public spaces through the use of mobile technologies. I discussTag' project is focused on social experiences and group play in public spaces, based on the awareness of other to encourage emergent social behaviours in an urban context. City space is used as a playground and passers

61

The birth of an infant decreases group spacing in a zoo-housed lowland gorilla group (Gorilla gorilla gorilla).  

PubMed

Changes in group composition can alter the behavior of social animals such as gorillas. Although gorilla births are presumed to affect group spacing patterns, there is relatively little data about how these events affect gorilla group cohesion. We investigated how members of a western lowland gorilla group (n?=?6) at Lincoln Park Zoo (Chicago, IL, USA) spaced themselves prior to and after the birth of an infant, to investigate changes in group cohesion. Gorillas were housed in an indoor-outdoor enclosure in which access to the outdoors was permitted when temperatures exceeded 5°C. We recorded spatial locations of each group member using 30-min group scans on tablet computers with an electronic map interface, as well as noting their access to outdoor areas. Data from the 4 months following the birth was compared to a control period corresponding to early pregnancy. We measured distances between all possible group dyads for each scan and subsequently calculated a mean distance between all group members. An ANOVA revealed that access to the outdoors had no effect on group spacing (F(1,56)?=?0.066, P?=?0.799). However, the presence of an infant resulted in a significant reduction in inter-individual distance (F(1,56)?=?23.988, P?=?0.000), decreasing inter-individual spacing by 12.5%. This information helps characterize the behavioral impact of a new birth on captive gorilla social structure and could potentially inform future management of breeding gorilla groups. PMID:25130595

Kurtycz, Laura M; Shender, Marisa A; Ross, Stephen R

2014-01-01

62

ISECG ToR 6 November 2007 INTERNATIONAL SPACE EXPLORATION COORDINATION GROUP  

E-print Network

ISECG ToR 6 November 2007 INTERNATIONAL SPACE EXPLORATION COORDINATION GROUP Terms of Reference In 2006, 14 space agencies1 began a series of discussions on global interests in space exploration, and developed a common set of key space exploration themes. This vision was articulated in `The Global

63

The space shuttle payload planning working groups. Volume 1: Astronomy  

NASA Technical Reports Server (NTRS)

The space astronomy missions to be accomplished by the space shuttle are discussed. The principal instrument is the Large Space Telescope optimized for the ultraviolet and visible regions of the spectrum, but usable also in the infrared. Two infrared telescopes are also proposed and their characteristics are described. Other instruments considered for the astronomical observations are: (1) a very wide angle ultraviolet camera, (2) a grazing incidence telescope, (3) Explorer-class free flyers to measure the cosmic microwave background, and (4) rocket-class instruments which can fly frequently on a variety of missions. The stability requirements of the space shuttle for accomplishing the astronomy mission are defined.

1973-01-01

64

Differential geometry of the space of orbits of a Coxeter group  

E-print Network

Differential-geometric structures on the space of orbits of a finite Coxeter group, determined by Groth\\'endieck residues, are calculated. This gives a construction of a 2D topological field theory for an arbitrary Coxeter group.

Boris Dubrovin

1993-03-27

65

Differential geometry of the space of orbits of a Coxeter group  

Microsoft Academic Search

Differential-geometric structures on the space of orbits of a finite Coxeter group, determined by Groth\\\\'endieck residues, are calculated. This gives a construction of a 2D topological field theory for an arbitrary Coxeter group.

Boris Dubrovin

1993-01-01

66

Pc-facs.  

PubMed

PC-FACS (Fast Article Critical Summaries for Clinicians in Palliative Care) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org. PMID:25614970

Zhukovsky, Donna S

2015-03-01

67

Towards a European vision for space exploration: Recommendations of the Space Advisory Group of the European Commission  

Microsoft Academic Search

As a result of increasing public and political interest in ‘space’ (i.e. solar system) exploration at the global scale, the Space Advisory Group of the European Commission has evaluated the situation in Europe with regard to its potential to participate in this ambitious global enterprise. Aspects of science, technology, environment and safety, society, spin-offs and international cooperation were all considered.

Gerda Horneck; Angioletta Coradini; Gerhard Haerendel; May-Britt Kallenrode; Paul Kamoun; Jean Pierre Swings; Alberto Tobias; Jean-Jacques Tortora

2010-01-01

68

THE WEYL QUANTIZATION AND THE QUANTUM GROUP QUANTIZATION OF THE MODULI SPACE OF  

E-print Network

56, 81T45, 57M25. Key words and phrases. Weyl quantization, quantum groups, topological quantum #12THE WEYL QUANTIZATION AND THE QUANTUM GROUP QUANTIZATION OF THE MODULI SPACE OF FLAT SU(2, for the moduli space of at SU(2)-connections on the 2-dimensional torus, the Weyl quantization

Uribe, Alejandro

69

The NASA EEE parts assurance group (NEPAG) - An evolving approach to maximizing space parts assurance resources  

Microsoft Academic Search

This paper describes the activities of the National Aeronautics and Space Administration's (NASA's) Electrical, Electronic and Electromechanical (EEE) Parts Assurance Group (NEPAG) in its role as a resource sharing and coordinating force in EEE Parts assurance for space flight missions. NEPAG is a new organization, barely two years old. The EEE parts world for space applications faces a number of

M. J. Sampson

2002-01-01

70

Space Weather Activities of IONOLAB Group: TEC Mapping  

Microsoft Academic Search

Being a key player in Space Weather, ionospheric variability affects the performance of both communication and navigation systems. To improve the performance of these systems, ionosphere has to be monitored. Total Electron Content (TEC), line integral of the electron density along a ray path, is an important parameter to investigate the ionospheric variability. A cost-effective way of obtaining TEC is

F. Arikan; A. Yilmaz; O. Arikan; I. Sayin; M. Gurun; K. E. Akdogan; S. A. Yildirim

2009-01-01

71

Teaching with Tablet PC's  

Microsoft Academic Search

Tablet PC's are traditional notebook computers with the ability to process digital ink by writing with a stylus. They have recently attracted attention as a potential tool for educational use. This paper describes the author's experience using the Tablet PC to conduct a CS1 course and a software engineering (SWE) course. The SWE course consisted primarily of PowerPoint lectures while

Kenrick Mock

2004-01-01

72

An orientation for the SU(2) -representation space of knot groups  

Microsoft Academic Search

The aim of this paper is to study the SU(2)-representation spaces of knot groups. For a given a knot k?S3 we denote by R(k) the space of equivalence classes of irreducible representations of the knot group ?1(S3?k) in SU(2) and we denote by Reg(k)?R(k) the space of regular representations. It is well known that Reg(k)?R(k) is a real one-dimensional manifold.The

Michael Heusener; Blaise Pascal

2003-01-01

73

The Picard group of the loop space of the Riemann sphere  

E-print Network

The loop space of the Riemann sphere consisting of all C^k or Sobolev W^{k,p} maps from the circle S^1 to the sphere is an infinite dimensional complex manifold. We compute the Picard group of holomorphic line bundles on this loop space as an infinite dimensional complex Lie group with Lie algebra the first Dolbeault group. The group of Mobius transformations G and its loop group LG act on this loop space. We prove that an element of the Picard group is LG-fixed if it is G-fixed; thus completely answer the question by Millson and Zombro about G-equivariant projective embedding of the loop space of the Riemann sphere.

Ning Zhang

2014-07-12

74

Group calls for space policies to transcend politics  

NASA Astrophysics Data System (ADS)

At a 22 May briefing, the American Institute of Aeronautics and Astronautics (AIAA) called on Congress to “establish space exploration policy goals which transcend partisan political differences.” AIAA president and former NASA administrator Michael Griffin said the “goal of establishing human capability to b e a space-faring species is not a short-term goal,” nor is it a goal that belongs to only one political party. “We will not reach long-term goals without a stable, coherent, sensible plan that transcends elections and leaders,” said Griffin, who has provided advice to Republican U.S. presidential candidate Mitt Romney. Griffin pointed to NASA's 2008 authorization as providing the kind of vision needed for NASA. The act called for human return to the Moon and preparation for the capability for permanent bases on the Moon, among other things, he said. “That's the kind of thing that we need. All of the goals espoused by the 2008 act were long-term, generational, strategic in scope,” Griffin said, adding that the act, which had bipartisan support, demonstrated “the kind of societal support, rather than political support, that I believe our space program deserves.”

Showstack, Randy

2012-06-01

75

Marathons versus Spaced Groups: Skin Conductance and the Effects of Time Distribution on Encounter Group Learning.  

ERIC Educational Resources Information Center

Randomly assigned 41 students to 2 twice-weekly groups, which met for 3 hours eight times; 2 marathons, which met continuously for 24 hours; and nontreatment control group. Treatment groups had significant positive changes on 14 of 15 measured personality variables between pre- and post-test, and positive change on all dependent measures between…

Loomis, Thomas P.

1988-01-01

76

Polyimides Containing Pendent Phosphine Oxide Groups for Space Applications  

NASA Technical Reports Server (NTRS)

As part of an ongoing materials development activity to produce high performance polymers that are durable to the space environment, phosphine oxide containing polyimides have been under investigation. A novel dianhydride was prepared from 2,5-dihydroxyphenyldiphenylphosphine oxide in good yield. The dianhydride was reacted with commercially available diamines, and a previously reported diamine was reacted with commercially available dianhydrides to prepare isomeric polyimides. The physical and mechanical properties, particularly thermal and optical properties, of the polymers were determined. One material exhibited a high glass transition temperature, high tensile properties, and low solar absorptivity. The chemistry, physical, and mechanical properties of these resins will be discussed.

Thompson, C. M.; Smith, J. G., Jr.; Watson, K. A.; Connell, J. W.

2002-01-01

77

PowerPC News  

NSDL National Science Digital Library

PowerPC News: Full text of an independent electronic magazine published every two weeks for users and developers who want the latest news about the IBM/Motorola/Apple microprocessor family and the systems.

78

PC-SPES (PDQ®)  

Cancer.gov

Expert-reviewed information summary about the use of PC-SPES as a treatment for prostate cancer. Note: The information in this summary is no longer being updated and is provided for reference purposes only.

79

Quantum group (CO)actions onG-spaces and quantum modules  

NASA Astrophysics Data System (ADS)

A generalized transformation theory is introduced by using quantum (non-commutative) spaces transformed by quantum Lie groups (Hopf algebras). In our method dual pairs of -quantum groups-comodule algebra. We use the quantized groupSU q (2) as a show case, and we determine its action on modules such as theq-oscillator and the quantum sphere. We also apply our method for the quantized Euclidean groupF q (E(2)) acting on a quantum homogeneous space. For the sphere case the construction leads to an analytic pseudodifferential vector field realization of the deformed algebra su q (2) on the quantum projective plane for north and south pole.

Arvanitoyeorgos, Andreas; Ellinas, Demosthenes

1996-12-01

80

Managing space for managed care: the challenge for a multispecialty group practice.  

PubMed

A project that began as an architectural study to determine space requirements and remedy space deficiencies for an academic medical center's faculty multispecialty group practice led to development of an analytical methodology for assessing real space needs and viable options for solutions in the context of the group's operational policies, physician practice patterns, and business goals. Major facility investments for new or renovated construction demand significant capital expenditure, which can severely affect a group's ability to complete as a financially viable player in a marketplace environment of increasingly competitive managed care delivery systems. The methodology created during this project helped the group practice to understand how they could optimize the use of existing space, minimize capital costs, and provide flexibility for future developments. PMID:10158956

Berkoff, M J; Burns, L A

1996-07-01

81

A corrected space group for Sulfolobus sulfataricus 5'-deoxy-5'-methylthioadenosine phosphorylase II.  

PubMed

5'-deoxy-5'-methylthioadenosine phosphorylase (MTAP) catalyzes the phosphorolytic cleavage of 5'-deoxy-5'-methylthioadenosine (MTA), a byproduct of polyamine biosynthesis. The Sulfolobus sulfataricus genome encodes two MTAPs. SsMTAP I has broad substrate specifity, accepting guanosine, inosine, adenosine and MTA, while SsMTAP II is specific for MTA. SsMTAP I forms a donut-shaped hexamer, while SsMTAP II is a hexamer formed from trimers packed face to face. The structure of SsMTAP II was originally determined in space group P1 (PDB entry 2a8y) and showed R32 pseudosymmetry. Post-analysis using phenix.xtriage showed that the correct space group is C2. Here, the structure refined in space group C2 is reported and the factors that initially led to the incorrect space-group assignment are discussed. PMID:22349226

Zhang, Yang; Zwart, Peter H; Ealick, Steven E

2012-03-01

82

Unusual space-group pseudo symmetry in crystals of human phosphopantothenoylcysteine decarboxylase  

SciTech Connect

Phosphopantothenoylcysteine (PPC) decarboxylase is an essential enzyme in the biosynthesis of coenzyme A and catalyzes the decarboxylation of PPC to phosphopantetheine. Human PPC decarboxylase has been expressed in Escherichia coli, purified and crystallized. The Laue class of the diffraction data appears to be {bar 3}m, suggesting space group R32 with two monomers per asymmetric unit. However, the crystals belong to the space group R3 and the asymmetric unit contains four monomers. The structure has been solved using molecular replacement and refined to a current R factor of 29%. The crystal packing can be considered as two interlaced lattices, each consistent with space group R32 and with the corresponding twofold axes parallel to each other but separated along the threefold axis. Thus, the true space group is R3 with four monomers per asymmetric unit.

Manoj, N.; Ealick, S.E. (Cornell)

2010-12-01

83

Root filtration spaces from Lie algebras and abstract root groups 1  

E-print Network

Root filtration spaces from Lie algebras and abstract root groups 1 Arjeh M. Cohen a, G Academy of Sciences, Kende u. 13-17, 1111 Budapest, Hungary Abstract Both Timmesfeld's abstract root subgroups and simple Lie algebras generated by extremal elements lead to root filtration spaces

Cohen, Arjeh M.

84

Unitary Space-Time Constellations Based on Finite Reflection Group Codes  

E-print Network

1 Unitary Space-Time Constellations Based on Finite Reflection Group Codes Terasan Niyomsataya, Ali diversity unitary space-time constellations for two transmitter antennas. Our proposed constellations unitary constellation designs in the literature. I. INTRODUCTION Consider a multiple-antenna system with M

Nevins, Monica

85

A MODULATED MULTIBAND Pc1 EVENT OBSERVED BY POLAR/EFI AROUND THE PLASMAPAUSE  

E-print Network

in amplitude, corresponding to classical Pc1 pearls. The repetition period was the same on ground and in space. Moreover, the repetition period of Pc1 pearls coincided with the period of simultaneous Pc4 waves observed by POLAR and on ground. The observations suggest that Pc1 pearls (EMIC waves in general) are modulated

California at Berkeley, University of

86

Position and Orientation Distributions for Non-Reversal Random Walks using Space-Group Fourier Transforms  

PubMed Central

This paper presents an efficient group-theoretic approach for computing the statistics of non-reversal random walks (NRRW) on lattices. These framed walks evolve on proper crystallographic space groups. In a previous paper we introduced a convolution method for computing the statistics of NRRWs in which the convolution product is defined relative to the space-group operation. Here we use the corresponding concept of the fast Fourier transform for functions on crystallographic space groups together with a non-Abelian version of the convolution theorem. We develop the theory behind this technique and present numerical results for two-dimensional and three-dimensional lattices (square, cubic and diamond). In order to verify our results, the statistics of the end-to-end distance and the probability of ring closure are calculated and compared with results obtained in the literature for the random walks for which closed-form expressions exist. PMID:21037950

Skliros, Aris; Park, Wooram; Chirikjian, Gregory S.

2010-01-01

87

The Local Population of White Dwarfs within 25 pc  

NASA Astrophysics Data System (ADS)

We have extended the detailed survey of the local white dwarf population from 20 pc to 25 pc, effectively doubling the sample volume to now include 231 stars. The present 25 pc has an estimated completeness of 70% (the corresponding 20 pc sample is now 85% complete). The space density of white dwarfs remains at 4.8 ± 0.5 x 10-3 pc-3. There exists a curious excess of single stars in the sample 70% vs 30% in systems with one or more companions. A pronounced apparent deficiency remains between the eleven known Sirius-like systems present in the 20 pc sample and only a single such system presently known in the extended 25 pc sample. Also demonstrated, using explicit individual white dwarf cooling ages, is the feasibility of estimating the white dwarf birth rates over the last ~ 5 Gyr.This work is supported by NSF grant AST-1413537

Holberg, Jay B.; Oswalt, Terry D.; Sion, Edward M.

2015-01-01

88

Challenges in Teaching Space Physics to Different Target Groups From Space Weather Forecasters to Heavy-weight Theorists  

NASA Astrophysics Data System (ADS)

Plasma physics as the backbone of space physics is difficult and thus the space physics students need to have strong foundations in general physics, in particular in classical electrodynamics and thermodynamics, and master the basic mathematical tools for physicists. In many universities the number of students specializing in space physics at Master's and Doctoral levels is rather small and the students may have quite different preferences ranging from experimental approach to hard-core space plasma theory. This poses challenges in building up a study program that has both the variety and depth needed to motivate the best students to choose this field. At the University of Helsinki we require all beginning space physics students, regardless whether they enter the field as Master's or Doctoral degree students, to take a one-semester package consisting of plasma physics and its space applications. However, some compromises are necessary. For example, it is not at all clear, how thoroughly Landau damping should be taught at the first run or how deeply should the intricacies of collisionless reconnection be discussed. In both cases we have left the details to an optional course in advanced space physics, even with the risk that the student's appreciation of, e.g., reconnection may remain at the level of a magic wand. For learning experimental work, data analysis or computer simulations we have actively pursued arrangements for the Master's degree students to get a summer employments in active research groups, which usually lead to the Master's theses. All doctoral students are members of research groups and participate in experimental work, data analysis, simulation studies or theory development, or any combination of these. We emphasize strongly "learning by doing" all the way from the weekly home exercises during the lecture courses to the PhD theses which in Finland consist typically of 4-6 peer-reviewed articles with a comprehensive introductory part.

Koskinen, H. E.

2008-12-01

89

National facilities study. Volume 5: Space research and development facilities task group  

NASA Technical Reports Server (NTRS)

With the beginnings of the U.S. space program, there was a pressing need to develop facilities that could support the technology research and development, testing, and operations of evolving space systems. Redundancy in facilities that was once and advantage in providing flexibility and schedule accommodation is instead fast becoming a burden on scarce resources. As a result, there is a clear perception in many sectors that the U.S. has many space R&D facilities that are under-utilized and which are no longer cost-effective to maintain. At the same time, it is clear that the U.S. continues to possess many space R&D facilities which are the best -- or among the best -- in the world. In order to remain world class in key areas, careful assessment of current capabilities and planning for new facilities is needed. The National Facility Study (NFS) was initiated in 1992 to develop a comprehensive and integrated long-term plan for future aerospace facilities that meets current and projected government and commercial needs. In order to assess the nation's capability to support space research and development (R&D), a Space R&D Task Group was formed. The Task Group was co-chaired by NASA and DOD. The Task Group formed four major, technologically- and functionally- oriented working groups: Human and Machine Operations; Information and Communications; Propulsion and Power; and Materials, Structures, and Flight Dynamics. In addition to these groups, three supporting working groups were formed: Systems Engineering and Requirements; Strategy and Policy; and Costing Analysis. The Space R&D Task Group examined several hundred facilities against the template of a baseline mission and requirements model (developed in common with the Space Operations Task Group) and a set of excursions from the baseline. The model and excursions are described in Volume 3 of the NFS final report. In addition, as a part of the effort, the group examined key strategic issues associated with space R&D facilities planning for the U.S., and these are discussed in Section 4 of this volume.

1994-01-01

90

PC Expo 2001  

NSDL National Science Digital Library

PC Expo 2001 wrapped up yesterday, and CNET offers a recap and its best of show awards at this site. Best of show categories include personal technology, emerging technology, enterprise product, business solution, and best overall. Each listing contains a brief description and a video segment. Also at the site are numerous short articles on various products and trends at the expo.

91

75 FR 62005 - Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Industries PC-6 airplanes, Fairchild Heli Porter PC-6 airplanes, or Fairchild-Hiller Corporation PC-6 airplanes. Subject (d) Air...ATA) Code 57: Wings. Reason (e) The...failure of the wing structure and subsequent...

2010-10-07

92

The space shuttle payload planning working groups. Volume 3: High energy astrophysics  

NASA Technical Reports Server (NTRS)

The findings of the High Energy Astrophysics working group of the space shuttle payload planning activity are presented. The objectives to be accomplished during space shuttle missions are defined as: (1) X-ray astronomy, (2) hard X-ray and gamma ray astronomy, and (3) cosmic ray astronomy. The instruments and test equipment required to accomplish the mission are identified. Recommendations for managing the installation of the equipment and conducting the missions are included.

1973-01-01

93

Johnson Space Center's Risk and Reliability Analysis Group 2008 Annual Report  

NASA Technical Reports Server (NTRS)

The Johnson Space Center (JSC) Safety & Mission Assurance (S&MA) Directorate s Risk and Reliability Analysis Group provides both mathematical and engineering analysis expertise in the areas of Probabilistic Risk Assessment (PRA), Reliability and Maintainability (R&M) analysis, and data collection and analysis. The fundamental goal of this group is to provide National Aeronautics and Space Administration (NASA) decisionmakers with the necessary information to make informed decisions when evaluating personnel, flight hardware, and public safety concerns associated with current operating systems as well as with any future systems. The Analysis Group includes a staff of statistical and reliability experts with valuable backgrounds in the statistical, reliability, and engineering fields. This group includes JSC S&MA Analysis Branch personnel as well as S&MA support services contractors, such as Science Applications International Corporation (SAIC) and SoHaR. The Analysis Group s experience base includes nuclear power (both commercial and navy), manufacturing, Department of Defense, chemical, and shipping industries, as well as significant aerospace experience specifically in the Shuttle, International Space Station (ISS), and Constellation Programs. The Analysis Group partners with project and program offices, other NASA centers, NASA contractors, and universities to provide additional resources or information to the group when performing various analysis tasks. The JSC S&MA Analysis Group is recognized as a leader in risk and reliability analysis within the NASA community. Therefore, the Analysis Group is in high demand to help the Space Shuttle Program (SSP) continue to fly safely, assist in designing the next generation spacecraft for the Constellation Program (CxP), and promote advanced analytical techniques. The Analysis Section s tasks include teaching classes and instituting personnel qualification processes to enhance the professional abilities of our analysts as well as performing major probabilistic assessments used to support flight rationale and help establish program requirements. During 2008, the Analysis Group performed more than 70 assessments. Although all these assessments were important, some were instrumental in the decisionmaking processes for the Shuttle and Constellation Programs. Two of the more significant tasks were the Space Transportation System (STS)-122 Low Level Cutoff PRA for the SSP and the Orion Pad Abort One (PA-1) PRA for the CxP. These two activities, along with the numerous other tasks the Analysis Group performed in 2008, are summarized in this report. This report also highlights several ongoing and upcoming efforts to provide crucial statistical and probabilistic assessments, such as the Extravehicular Activity (EVA) PRA for the Hubble Space Telescope service mission and the first fully integrated PRAs for the CxP's Lunar Sortie and ISS missions.

Valentine, Mark; Boyer, Roger; Cross, Bob; Hamlin, Teri; Roelant, Henk; Stewart, Mike; Bigler, Mark; Winter, Scott; Reistle, Bruce; Heydorn,Dick

2009-01-01

94

A Hilbert Space Operator Representation of Abelian Po-Groups of Bilinear Forms  

NASA Astrophysics Data System (ADS)

The existence of a non-trivial singular positive bilinear form Simon (J. Funct. Analysis 28, 377-385 (1978)) yields that on an infinite-dimensional complex Hilbert space H the set of bilinear forms F(H) is richer than the set of linear operators {V}(H). We show that there exists an structure preserving embedding of partially ordered groups from the abelian po-group {S}D(H) of symmetric bilinear forms with a fixed domain D on a Hilbert space {H} into the po-group of linear symmetric operators on a dense linear subspace of an infinite dimensional complex Hilbert spacel 2(M). Moreover, if we restrict ourselves to the positive parts of the above mentioned po-groups, we can embed positive bilinear forms into corresponding positive linear operators.

Janda, Ji?í; Paseka, Jan

2015-02-01

95

The IBM PC at NASA Ames  

NASA Technical Reports Server (NTRS)

Like many large companies, Ames relies very much on its computing power to get work done. And, like many other large companies, finding the IBM PC a reliable tool, Ames uses it for many of the same types of functions as other companies. Presentation and clarification needs demand much of graphics packages. Programming and text editing needs require simpler, more-powerful packages. The storage space needed by NASA's scientists and users for the monumental amounts of data that Ames needs to keep demand the best database packages that are large and easy to use. Availability to the Micom Switching Network combines the powers of the IBM PC with the capabilities of other computers and mainframes and allows users to communicate electronically. These four primary capabilities of the PC are vital to the needs of NASA's users and help to continue and support the vast amounts of work done by the NASA employees.

Peredo, James P.

1988-01-01

96

Chromosomal Distribution of PcG Proteins during Drosophila Development  

Microsoft Academic Search

Polycomb group (PcG) proteins are able to maintain the memory of silent transcriptional states of homeotic genes throughout development. In Drosophila, they form multimeric complexes that bind to specific DNA regulatory elements named PcG response elements (PREs). To date, few PREs have been identified and the chromosomal distribution of PcG proteins during development is unknown. We used chromatin immunoprecipitation (ChIP)

Nicolas Nègre; Jérôme Hennetin; Ling V Sun; Sergey Lavrov; Michel Bellis; Kevin P White; Giacomo Cavalli

2006-01-01

97

Nuclear safety policy working group recommendations on nuclear propulsion safety for the space exploration initiative  

Microsoft Academic Search

An interagency Nuclear Safety Working Group (NSPWG) was chartered to recommend nuclear safety policy, requirements, and guidelines for the Space Exploration Initiative (SEI) nuclear propulsion program. These recommendations, which are contained in this report, should facilitate the implementation of mission planning and conceptual design studies. The NSPWG has recommended a top-level policy to provide the guiding principles for the development

Albert C. Marshall; James H. Lee; William H. McCulloch; J. Charles Sawyer Jr.; Robert A. Bari; Hatice S. Cullingford; Alva C. Hardy; George F. Niederauer; Kerry Remp; John W. Rice

1993-01-01

98

Combinatorial R-trees as generalized Cayley graphs for fundamental groups of one-dimensional spaces  

E-print Network

In their study of fundamental groups of one-dimensional path-connected compact metric spaces, Cannon and Conner have asked: Is there a tree-like object that might be considered the topological Cayley graph? We answer this question in the positive and provide a combinatorial description of such an object.

Fischer, Hanspeter

2011-01-01

99

INFLUENCE OF SPAWNING GROUP SIZE AND SPACE ON REPRODUCTION BY SHEEPSHEAD MINNOWS, CYPRINODON VARIEGATUS  

EPA Science Inventory

Cripe, G.M., R.L. Hemmer and L.R. Goodman. In press. Influence of Spawning Group Size and Space on Reproduction Variability of Sheepshead Minnows, Cyprinodon variegatus (Abstract). To be presented at the SETAC Fourth World Congress, 14-18 November 2004, Portland, OR. 1 p. (ERL,GB...

100

School Mathematics Study Group, Unit Number One. Chapter 1 - Structuring Space. Chapter 2 - Functions.  

ERIC Educational Resources Information Center

This is the first unit of a 15-unit School Mathematics Study Group (SMSG) mathematics text for high school students. Topics presented in the first chapter (Structuring Space) include: lines and points; planes; intersections; intersections of lines and planes; betweenness and segments; separation; angles; locating positions and points; coordinates;…

Stanford Univ., CA. School Mathematics Study Group.

101

Group Decision Fiascoes Continue: Space Shuttle Challenger and a Revised Groupthink Framework  

Microsoft Academic Search

This paper reviews the decision situation surrounding the decision to launch the space shuttle Challenger in January 1986 in the light of the groupthink hypothesis. A revised framework is presented that proposes time and leadership style as moderators of the manner in which group characteristics lead to groupthink symptoms.

Gregory Moorhead; Richard Ference; Chris P. Neck

1991-01-01

102

Cooperation Without Memory or Space: Tags, Groups and the Prisoner's Dilemma  

E-print Network

Cooperation Without Memory or Space: Tags, Groups and the Prisoner's Dilemma David Hales Department] model demonstrated that image scoring produces high cooperation between strangers in the Prisoner formalise this kind of encounter using the ubiquitous form of the two player single round Prisoner's Dilemma

Hales, David

103

Environmental interactions in Space Exploration: Announcement of the formation of an Environmental Interactions Working Group  

NASA Technical Reports Server (NTRS)

With the advent of the Space Exploration Initiative, the possibility of designing and using systems on scales not heretofore attempted presents exciting new challenges in systems design and space science. The environments addressed by the Space Exploration Initiative include the surfaces of the Moon and Mars, as well as the varied plasma and field environments which will be encountered by humans and cargo enroute to these destinations. Systems designers will need to understand environmental interactions and be able to model these mechanisms from the earliest conceptual design stages through design completion. To the end of understanding environmental interactions and establishing robotic precursor mission requirements, an Environmental Interactions Working Group has been established as part of the Robotic Missions Working Group. The current paper describes the working group and gives an update of its current activities. Working group charter and operation are reviewed, background information on the environmental interactions and their characteristics is offered, and the current status of the group's activities is presented along with anticipations for the future.

Kolecki, Joseph C.; Hillard, G. Barry

1991-01-01

104

Future In-Space Operations (FISO): A Working Group and Community Engagement  

NASA Technical Reports Server (NTRS)

Long-duration human capabilities beyond low Earth orbit (LEO), either in support of or as an alternative to lunar surface operations, have been assessed at least since the late 1960s. Over the next few months, we will present short histories of concepts for long-duration, free-space human habitation beyond LEO from the end of the Apollo program to the Decadal Planning Team (DPT)/NASA Exploration Team (NExT), which was active in 1999 2000 (see Forging a vision: NASA s Decadal Planning Team and the origins of the Vision for Space Exploration , The Space Review, December 19, 2005). Here we summarize the brief existence of the Future In-Space Operations (FISO) working group in 2005 2006 and its successor, a telecon-based colloquium series, which we co-moderate.

Thronson, Harley; Lester, Dan

2013-01-01

105

Definition of spacecraft standard interfaces by the NASA Space Assembly and Servicing Working Group (SASWG)  

NASA Technical Reports Server (NTRS)

The purpose of the NASA Space Assembly and Servicing Working Group (SASWG) is to study enabling technologies for on-orbit spacecraft maintenance and servicing. One key technology required for effective space logistics activity is the development of standard spacecraft interfaces, including the 'Basic Set' defined by NASA, the U.S. Space Command, and industry panelists to be the following: (1) navigation aids; (2) grasping, berthing, and docking; and (3) utility connections for power, data, and fluids. Draft standards have been prepared and referred to professional standards organizations, including the AIAA, EIA, and SAE space standards committee. The objective of the SASWG is to support these committees with the technical expertise required to prepare standards, guidelines, and recommended practices which will be accepted by the ANSI and international standards organizations, including the ISO, IEC, and PASC.

Radtke, Robert; Woolley, Charles; Arnold, Lana

1993-01-01

106

Graphically oriented method for obtaining atomic displacement fields in crystals from irreducible representations of space groups  

NASA Astrophysics Data System (ADS)

A method for obtaining distortion fields in a crystal from a given irreducible representation of the underlying space group is described. The method, based on projection operators of group theory, is graphically oriented and therefore calculation-free. For an example (space group P4¯21m), complete sets of representation matrices are analytically calculated for all irreducible representations which correspond to all wave vectors of the form k=(q,q,0). All 96 linear independent atomic displacement modes in the (3×3×1) supercell, which are induced by the two irreducible representations with k=(13,13,0), are explicitly determined: the obtained atomic displacement fields are plane waves with wave vector k.

Gutmann, Jürgen K.; Böhm, Horst

2000-06-01

107

Phase-space shapes of clusters and rich groups of galaxies  

NASA Astrophysics Data System (ADS)

Context. Clusters and groups of galaxies are highly aspherical, with shapes approximated by nearly prolate ellipsoids of revolution. An equally fundamental property is the shape of these objects in velocity space which is the anisotropy of the global velocity dispersion tensor. Although many studies address the problem of the shape in position space, there has been no attempt to measure shapes in velocity space. Aims: Here we make use of kinematical data comprising ~600 nearby clusters and rich groups of galaxies from the Sloan Digital Sky Survey to place constraints on the phase-space shapes of these objects, i.e. their shapes in both position and velocity space. Methods: We show that the line of sight velocity dispersion normalised by a mass-dependent velocity scale correlates with the apparent elongation, with circular (elongated) clusters exhibiting an excessive (decremental) normalised velocity dispersion. This correlation holds for dynamically young or old clusters and, therefore, it originates from projecting their intrinsic phase-space shapes rather than from dynamical evolution. It signifies that clusters are preferentially prolate not only in position space, but also in velocity space. This property allows us to break the degeneracy between oblate and prolate models and thus to deproject the apparent elongations and the line of sight velocity dispersions obtaining constraints on the axial ratios of the ellipsoids approximating cluster shapes in 3D position or velocity space. Results: The distribution of the axial ratios in position space is found to be well approximated by a Gaussian with a mean, ? = 0.66 ± 0.01, and a dispersion, ? = 0.07 ± 0.008. The velocity ellipsoids representing the shapes in velocity space are more spherical, with a mean axial ratio of 0.78 ± 0.03. Conclusions: The mean axial ratio of the velocity ellipsoids points to a highly anisotropic velocity distribution and, therefore, to a strong dependance of the observed velocity dispersions on the angle between the line of sight and the semi-principle axes of the clusters. This finding has important implications for mass measurements based on the line of sight velocity dispersion profiles in individual clusters. For typical axial ratios of the velocity ellipsoids in the analysed cluster sample, systematic errors on the mass estimates inferred from the line of sight velocity dispersions become comparable to statistical uncertainties for galaxy clusters with as few as 40 spectroscopic redshifts.

Wojtak, Rados?aw

2013-11-01

108

The space shuttle payload planning working groups. Volume 8: Earth and ocean physics  

NASA Technical Reports Server (NTRS)

The findings and recommendations of the Earth and Ocean Physics working group of the space shuttle payload planning activity are presented. The requirements for the space shuttle mission are defined as: (1) precision measurement for earth and ocean physics experiments, (2) development and demonstration of new and improved sensors and analytical techniques, (3) acquisition of surface truth data for evaluation of new measurement techniques, (4) conduct of critical experiments to validate geophysical phenomena and instrumental results, and (5) development and validation of analytical/experimental models for global ocean dynamics and solid earth dynamics/earthquake prediction. Tables of data are presented to show the flight schedule estimated costs, and the mission model.

1973-01-01

109

Fredholm and spectral properties of Toeplitz operators on H{sup p} spaces over ordered groups  

SciTech Connect

We consider Toeplitz operators on the spaces H{sup p}(G), 1< p<{infinity}, associated with a compact connected Abelian group G whose character group is ordered and, in the case of total order, prove a theorem on the Fredholm index for those operators which have continuous symbols which generalizes the classical Gohberg-Krein theorem. The results thus obtained are applied to the spectral theory of Toeplitz operators and examples where the index is evaluated explicitly are considered. Bibliography: 22 titles.

Mirotin, Adolf R [Gomel State University, Gomel (Belarus)

2011-05-31

110

Planning and managing future space facility projects. [management by objectives and group dynamics  

NASA Technical Reports Server (NTRS)

To learn how ground-based personnel of a space project plan and organize their work and how such planning and organizing relate to work outcomes, longitudinal study of the management and execution of the Space Lab Mission Development Test 3 (SMD 3) was performed at NASA Ames Research Center. A view of the problems likely to arise in organizations and some methods of coping with these problems are presented as well as the conclusions and recommendations that pertain strictly to SMD 3 management. Emphasis is placed on the broader context of future space facility projects and additional problems that may be anticipated. A model of management that may be used to facilitate problem solving and communication - management by objectives (MBO) is presented. Some problems of communication and emotion management that MBO does not address directly are considered. Models for promoting mature, constructive and satisfying emotional relationships among group members are discussed.

Sieber, J. E.; Wilhelm, J. A.; Tanner, T. A.; Helmreich, R. L.; Burgenbauch, S. F.

1979-01-01

111

Range Commanders Council Meteorology Group 88th Meeting: NASA Marshall Space Flight Center Task Report, 2004  

NASA Technical Reports Server (NTRS)

Supported Return-to-Flight activities by providing surface climate data from Kennedy Space Center used primarily for ice and dew formation studies, and upper air wind analysis primarily used for ascent loads analyses. The MSFC Environments Group's Terrestrial and Planetary Environments Team documented Space Shuttle day-of-launch support activities by publishing a document in support of SSP Return-to-Flight activities entitled "Space Shuttle Program Flight Operations Support". The team also formalized the Shuttle Natural Environments Technical Panel and chaired the first special session of the SSP Natural Environments Panel meeting at KSC, November 4-7,2003.58 participants from NASA, DOD and other government agencies from across the country attended the meeting.

Roberts, Barry C.

2004-01-01

112

Cohomologies of Configuration Spaces and Higher-Dimensional Polylogarithms in Renormalization Group Problems  

SciTech Connect

The deviation from commutativity of the renormalization and the action of all linear partial differential operators is the main source of the anomalies in quantum field theory, including the renormalization group action. This deviation is characterized by certain 'renormalization cocycles' that are related to cohomologies of the so called (ordered) configuration spaces. Cohomological differential equations that determine the renormalization cocycles up to the renormalization freedom are obtained. The solution of these equations requires introducing transcendental extensions related to higher-dimensional polylogarithms.

Nikolov, Nikolay M. [Institute for Nuclear Research and Nuclear Energy, Tsarigradsko Chaussee 72, BG-1784 Sofia (Bulgaria)

2010-06-17

113

Report from the MPP Working Group to the NASA Associate Administrator for Space Science and Applications  

NASA Technical Reports Server (NTRS)

NASA's Office of Space Science and Applications (OSSA) gave a select group of scientists the opportunity to test and implement their computational algorithms on the Massively Parallel Processor (MPP) located at Goddard Space Flight Center, beginning in late 1985. One year later, the Working Group presented its report, which addressed the following: algorithms, programming languages, architecture, programming environments, the way theory relates, and performance measured. The findings point to a number of demonstrated computational techniques for which the MPP architecture is ideally suited. For example, besides executing much faster on the MPP than on conventional computers, systolic VLSI simulation (where distances are short), lattice simulation, neural network simulation, and image problems were found to be easier to program on the MPP's architecture than on a CYBER 205 or even a VAX. The report also makes technical recommendations covering all aspects of MPP use, and recommendations concerning the future of the MPP and machines based on similar architectures, expansion of the Working Group, and study of the role of future parallel processors for space station, EOS, and the Great Observatories era.

Fischer, James R.; Grosch, Chester; Mcanulty, Michael; Odonnell, John; Storey, Owen

1987-01-01

114

Inhibition of Prohormone Convertases PC1/3 and PC2 by 2,5-Dideoxystreptamine Derivatives  

PubMed Central

The prohormone convertases PC1/3 and PC2 are eukaryotic serine proteases involved in the proteolytic maturation of peptide hormone precursors and are implicated in a variety of pathological conditions, including obesity, diabetes, and neurodegenerative diseases. In this work, we screened 45 compounds obtained by derivatization of a 2,5-dideoxystreptamine scaffold with guanidinyl and aryl substitutions for convertase inhibition. We identified four promising PC1/3 competitive inhibitors and three PC2 inhibitors that exhibited various inhibition mechanisms (competitive, noncompetitive, and mixed), with sub- and low micromolar inhibitory potency against a fluorogenic substrate. Low micromolar concentrations of certain compounds blocked the processing of the physiological substrate proglucagon. The best PC2 inhibitor effectively inhibited glucagon synthesis, a known PC2-mediated process, in a pancreatic cell line; no cytotoxicity was observed. We also identified compounds that were able to stimulate both 87 kDa PC1/3 and PC2 activity, behavior related to the presence of aryl groups on the dideoxystreptamine scaffold. By contrast, inhibitory activity was associated with the presence of guanidinyl groups. Molecular modeling revealed interactions of the PC1/3 inhibitors with the active site that suggest structural modifications to further enhance potency. In support of kinetic data suggesting that PC2 inhibition probably occurs via an allosteric mechanism, we identified several possible allosteric binding sites using computational searches. It is noteworthy that one compound was found to both inhibit PC2 and stimulate PC1/3. Because glucagon acts in functional opposition to insulin in blood glucose homeostasis, blocking glucagon formation and enhancing proinsulin cleavage with a single compound could represent an attractive therapeutic approach in diabetes. PMID:22169851

Vivoli, Mirella; Caulfield, Thomas R.; Martínez-Mayorga, Karina; Johnson, Alan T.; Jiao, Guan-Sheng

2012-01-01

115

The Scientific Capabilities of the James Webb Space Telescope Jonathan P. Gardner and the JWST Science Working Group  

E-print Network

The Scientific Capabilities of the James Webb Space Telescope Jonathan P. Gardner and the JWST.p.gardner@nasa.gov #12;The Scientific Capabilities of the James Webb Space Telescope Jonathan P. Gardner and the JWST Science Working Group 1. Introduction The James Webb Space Tele- scope (JWST; Figure 1) is a large (25 m2

Sirianni, Marco

116

A systematic method to identify the space group from PED and CBED patterns part II--practical examples.  

PubMed

Precession Electron Diffraction and Convergent-Beam Electron Diffraction are used in a complementary way to determine the space group of three known structures following the general method described in the first part of this paper. The selected structures concern a monoclinic example (coesite SiO(2) with space group C2/c) and two cubic examples (?-Al(4)Cu(9) with space group P43[combining overline]m and pyrite FeS(2) with space group Pa3[combining overline]). For each case, a minimum number of zone axis patterns are used to determine the space group without ambiguity, which illustrates the simplicity and reliability of the method. PMID:22749238

Jacob, D; Ji, G; Morniroli, J P

2012-10-01

117

A Perceptual Phonetic Similarity Space for Languages: Evidence from Five Native Language Listener Groups1  

PubMed Central

The goal of the present study was to devise a means of representing languages in a perceptual similarity space based on their overall phonetic similarity. In Experiment 1, native English listeners performed a free classification task in which they grouped 17 diverse languages based on their perceived phonetic similarity. A similarity matrix of the grouping patterns was then submitted to clustering and multidimensional scaling analyses. In Experiment 2, an independent group of native English listeners sorted the group of 17 languages in terms of their distance from English. Experiment 3 repeated Experiment 2 with four groups of non-native English listeners: Dutch, Mandarin, Turkish and Korean listeners. Taken together, the results of these three experiments represent a step towards establishing an approach to assessing the overall phonetic similarity of languages. This approach could potentially provide the basis for developing predictions regarding foreign-accented speech intelligibility for various listener groups, and regarding speech perception accuracy in the context of background noise in various languages. PMID:21179563

Bradlow, Ann; Clopper, Cynthia; Smiljanic, Rajka; Walter, Mary Ann

2010-01-01

118

NASA PC software evaluation project  

NASA Technical Reports Server (NTRS)

The USL NASA PC software evaluation project is intended to provide a structured framework for facilitating the development of quality NASA PC software products. The project will assist NASA PC development staff to understand the characteristics and functions of NASA PC software products. Based on the results of the project teams' evaluations and recommendations, users can judge the reliability, usability, acceptability, maintainability and customizability of all the PC software products. The objective here is to provide initial, high-level specifications and guidelines for NASA PC software evaluation. The primary tasks to be addressed in this project are as follows: to gain a strong understanding of what software evaluation entails and how to organize a structured software evaluation process; to define a structured methodology for conducting the software evaluation process; to develop a set of PC software evaluation criteria and evaluation rating scales; and to conduct PC software evaluations in accordance with the identified methodology. Communication Packages, Network System Software, Graphics Support Software, Environment Management Software, General Utilities. This report represents one of the 72 attachment reports to the University of Southwestern Louisiana's Final Report on NASA Grant NGT-19-010-900. Accordingly, appropriate care should be taken in using this report out of context of the full Final Report.

Dominick, Wayne D. (editor); Kuan, Julie C.

1986-01-01

119

Wanted: A Solid, Reliable PC  

ERIC Educational Resources Information Center

This article discusses PC reliability, one of the most pressing issues regarding computers. Nearly a quarter century after the introduction of the first IBM PC and the outset of the personal computer revolution, PCs have largely become commodities, with little differentiating one brand from another in terms of capability and performance. Most of…

Goldsborough, Reid

2004-01-01

120

Unfolding of electronic structure through induced representations of space groups: Application to Fe-based superconductors  

NASA Astrophysics Data System (ADS)

We revisit the problem that relevant parts of band structures for a given cell choice can reflect exact or approximate higher symmetries of subsystems in the cell and can therefore be significantly simplified by an unfolding procedure that recovers the higher symmetry. We show that band-structure unfolding can be understood as projection onto induced irreducible representations of a group obtained by extending the original group of translations with a number of additional symmetry operations. The resulting framework allows us to define a generalized unfolding procedure that includes the point group operations and can be applied to any quantity in the reciprocal space. The unfolding of the Brillouin zone follows naturally from the properties of the induced irreducible representations. In this context, we also introduce a procedure to derive tight-binding models of reduced dimensionality by making use of point group symmetries. Further, we show that careful consideration of unfolding has important consequences on the interpretation of angle-resolved photoemission experiments. Finally, we apply the unfolding procedure to various representative examples of Fe-based superconductor compounds and show that the one-iron picture arises as an irreducible representation of the glide-reflection group, and we comment on the consequences for the interpretation of one-iron versus two-iron Brillouin zone representations.

Tomi?, Milan; Jeschke, Harald O.; Valentí, Roser

2014-11-01

121

The space shuttle payload planning working groups. Volume 5: Solar physics  

NASA Technical Reports Server (NTRS)

The findings of the Solar Physics working group of the space shuttle payload planning activity are presented. The areas to be investigated by the solar physics experiments are: (1) the production of mechanical energy in the subphotospheric layers and its transport and dissipation in the upper layers of the atmosphere, (2) the mass flux from the subphotospheric layers into the chromosphere and corona and beyond the solar wind, (3) solar activity and its relationship to magnetic fields, and (4) the production of solar flares. The approach to be followed in conducting the experiments and the equipment required are defined.

1973-01-01

122

A Fun and Effective Exercise for Understanding Lattices and Space Groups  

NSDL National Science Digital Library

This activity uses figures from Francois Brisse as Esher drawings to teach students about 2-dimensional symmetry, especially involving translation. This exercise is based on discovery learning. Students need little introduction to lattices and space groups. They can figure things out for themselves. For example, they will figure out what a glide plane is, and if you tell them ahead of time it takes away from the learning experience. The last question, which asks them to make their own symmetrical drawings, is difficult but often leads to some spectacular results.

Dexter Perkins

123

The space shuttle payload planning working groups. Volume 4: Life sciences  

NASA Technical Reports Server (NTRS)

The findings of the Life Sciences working group of the space shuttle payload planning activity are presented. The objectives of the Life Sciences investigations are: (1) to continue the research directed at understanding the origin of life and the search for extraterrestrial evidence of life, (2) biomedical research to understand mechanisms and provide criteria for support of manned flight, (3) technology development for life support, protective systems, and work aids for providing environmental control, and (4) to study basic biological functions at all levels or organization influenced by gravity, radiation, and circadian rhythms. Examples of candidate experimental schedules and the experimental package functional requirements are included.

1973-01-01

124

Outstanding Student Paper Awards: Atmospheric and Space Electricity Focus Group; Volcanology, Geochemistry, and Petrology  

NASA Astrophysics Data System (ADS)

The following members received Outstanding Student Paper Awards at the 2004 Fall Meeting in San Francisco, California. (Winners in other sections and focus groups will be announced in subsequent issues of Eos).Atmospheric and Space ElectricityToru Adachi, Tohoku University, Spatial and temporal structures of sprites observed with the array photometer on board of the ROCSAT-2 satellite.Robert Marshall, Stanford University, High time resolution telescopic imaging of fine structure in sprites.Robert Olsen, University of Florida, Leader/return-stroke-like processes in the initial stage of rocket-triggered lightning.

2005-02-01

125

A PC based fault diagnosis expert system  

NASA Technical Reports Server (NTRS)

The Integrated Status Assessment (ISA) prototype expert system performs system level fault diagnosis using rules and models created by the user. The ISA evolved from concepts to a stand-alone demonstration prototype using OPS5 on a LISP Machine. The LISP based prototype was rewritten in C and the C Language Integrated Production System (CLIPS) to run on a Personal Computer (PC) and a graphics workstation. The ISA prototype has been used to demonstrate fault diagnosis functions of Space Station Freedom's Operation Management System (OMS). This paper describes the development of the ISA prototype from early concepts to the current PC/workstation version used today and describes future areas of development for the prototype.

Marsh, Christopher A.

1990-01-01

126

Group-galaxy correlations in redshift space as a probe of the growth of structure  

E-print Network

We investigate the use of the cross-correlation between galaxies and galaxy groups to measure redshift-space distortions (RSD) and thus probe the growth rate of cosmological structure. This is compared to the classical approach based on using galaxy auto-correlation. We make use of realistic simulated galaxy catalogues that have been constructed by populating simulated dark matter haloes with galaxies through halo occupation prescriptions. We adapt the classical RSD dispersion model to the case of the group-galaxy cross-correlation function and estimate the RSD parameter {\\beta} by fitting both the full anisotropic correlation function {\\xi}(rp, {\\pi}) and its multipole moments. In addition, we define a modified version of the latter statistics by truncating the multipole moments to exclude strongly non-linear distortions at small transverse scales. We fit these three observable quantities in our set of simulated galaxy catalogues and estimate statistical and systematic errors on {\\beta} for the case of galax...

Mohammad, Faizan G; Bianchi, Davide; Guzzo, Luigi; Peacock, John A

2015-01-01

127

Hubble Space Telescope Images of Stephan's Quintet: Star Cluster Formation in a Compact Group Environment  

E-print Network

Analysis of Hubble Space Telescope/Wide Field Planetary Camera 2 images of Stephan's Quintet, Hickson Compact Group 92, yielded 115 candidate star clusters (with V-I < 1.5). Unlike in merger remants, the cluster candidates in Stephan's Quintet are not clustered in the inner regions of the galaxies; they are spread over the debris and surrounding area. Specifically, these sources are located in the long sweeping tail and spiral arms of NGC 7319, in the tidal debris of NGC 7318B/A, and in the intragroup starburst region north of these galaxies. Analysis of the colors of the clusters indicates several distinct epochs of star formation that appear to trace the complex history of dynamical interactions in this compact group.

S. C. Gallagher; J. C. Charlton; S. D. Hunsberger; D. Zaritsky; B. C. Whitmore

2001-03-31

128

A new verification of Kovalev's tables of irreducible representations of the space groups  

NASA Astrophysics Data System (ADS)

In the application of representation theory to physical and crystallographic problems, Kovalev's tables provide a uniquely reliable and complete source for the required irreducible representations of the space groups. A number of programs based on these tables, designed to automate the lengthy calculations involved, generate non-physical or incorrect solutions to some problems, raising questions over the validity of Kovalev's work. In this work the tables are verified to the point of homomorphism with the groups and subgroups that they represent through the use of the digitized versions of the tables used in SARAh. The results support the correctness of Kovalev's definitions, highlighting difficulties in interpreting the tables themselves and some general failings of the programs used in the application of representation theory to physical problems.

Davies, Z. L.; Wills, A. S.

2008-03-01

129

Alveolar Gas - PC Version  

NSDL National Science Digital Library

Alveolar Gas is a computer program that lets you study some of the physiological factors that affect the composition of alveolar and expired gases. Such factors include dead space, tidal volume, the frequency of breathing, and the rates of oxygen consumption and carbon dioxide production. A worksheet is included.

1998-07-01

130

A Minuet of Galaxies: Hickson Compact Group 87 as Viewed by the Hubble Space Telescope  

NASA Astrophysics Data System (ADS)

HCG 87 was selected from 3 visually, and scientifically, intriguing compact groups for HST WFPC2 imaging by members of the public who visited the Hubble Heritage website (http://heritage.stsci.edu) and registered their votes. The HST exposures in four filters (F450W, F555W, F675W and F814W) of the winning target were used to create a color image, released in September 1999 as part of the Hubble Heritage Team's program to provide images for public outreach and education. Along with these data and image, we present a preliminary determination of colors and brightness profiles for the large galaxies in this group. The pair of apparently interacting galaxies each harbour AGN. One is a ``boxy'' spiral with a prominent dust lane and the other a lenticular galaxy. Another group member is a smaller starbursting spiral galaxy. Our goal is to study their stellar populations and examine the influence of active nuclei on star formation histories. In addition, a similar analysis is being performed on all faint, extended objects distributed throughout the group. For those determined to be tidal dwarf galaxies, we plan to appraise the role gravitational instabilities play during their formation. Support for this work was provided by NASA through grant number GO-07632.01-96A from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under the NASA contract NAS5-26555.

English, J.; Hunsberger, S.; Charlton, J.; Hamilton, F.; Bond, H. E.; Christian, C. A.; Frattare, L.; Levay, Z.; Noll, K.

2000-05-01

131

The Lorentz Group, Noncommutative Space-Time, and Nonlinear Electrodynamics in Majorana-Oppenheimer Formalism  

E-print Network

Non-linear electrodynamics arising in the frames of field theories in non-commutative space-time is examined on the base of the Riemann-Silberstein-Majorana-Oppenheimer formalism. The problem of form-invariance of the non-linear constitutive relations governed by six non-commutative parameters \\theta_{kl} \\sim {\\bf K} = {\\bf n} + i {\\bf m} is explored in detail on the base of the complex orthogonal group theory SO(3.C). Two Abelian 2-parametric small groups, isomorphic to each other in abstract sense, and leaving unchangeable the extended constitutive relations at arbitrary six parameters \\theta_{kl} of effective media have been found, their realization depends explicitly on invariant length {\\bf K}^{2}. In the case of non-vanishing length a special reference frame in which the small group has the structure SO(2) \\otimes SO(1,1) has been found. In isotropic case no such reference frame exists. The way to interpret both Abelian small groups in physical terms consists in factorizing corresponding Lorentz transformations into Euclidean rotations and boosts. In the context of general study of various dual symmetries in non-commutative field theory, it is demonstrated explicitly that the non-linear constitutive equations in non-commutative electrodynamics are not invariant under continuous dual rotations, instead only invariance under discrete dual transformation exists.

V. Red'kov; E. Tolkachev

2011-09-09

132

Intraspecific variation in space use, group size, and mating systems of caviomorph rodents  

PubMed Central

Intraspecific variation in social systems is widely recognized across many taxa, and specific models, including polygamy potential, resource defense, and resource dispersion, have been developed to explain the relationship between ecological variation and social organization. Although mammals from temperate North America and Eurasia have provided many insights into this relationship, rodents from the Neotropics and temperate South America have largely been ignored. In this review we focus on reports documenting intraspecific variation in spacing systems, group size, and mating systems of caviomorphs. This large group of New World hystricognath rodents occupies a diverse array of habitats; thus, members of the same species potentially exhibit different social systems in response to different ecological conditions. Spatial patterns vary in response to a diverse array of factors, including predation, food availability, population density, and soil characteristics. Changes in group size typically correlate with changes in resource availability, particularly food. Mating systems generally reflect the ability of males to control access to females, which may depend on population density or food distribution. In general, social organization in caviomorphs fits predictions of resource-based models; however, most studies have been purely observational, involving small numbers of animals over short time periods and reporting qualitative rather than quantitative levels of ecological correlates. In future studies the use of molecular techniques and controlled, experimental manipulations can increase our understanding of intraspecific variation in caviomorph social systems. This understudied group of rodents offers excellent opportunities to provide insights into the influence of ecological conditions on behavior such as social systems. PMID:22328790

Maher, Christine R.; Burger, Joseph Robert

2012-01-01

133

Structure of human salivary ?-amylase crystallized in a C-centered monoclinic space group  

PubMed Central

Human salivary ?-amylase (HSA) is a major secretory protein component of saliva and has important biological functions, including the initial digestion of starch. HSA acts as a monomer and mediates the hydrolysis of ?-1,4-glucosidic linkages in oligosaccharides. To date, all published crystal structures of HSA have been crystallized as monomers in space group P212121. Here, the serendipitous purification, crystallization and ultimate structure determination of a HSA non-crystallographic symmetry (NCS) dimer, while attempting to purify human carbonic anhydrase VI (HCA VI) from saliva using an affinity resin for ?-class carbonic anhydrases, is presented. On further investigation, it was shown that HSA could only be copurified using the affinity resin in the presence of HCA VI which is glycosylated and not the non-glycosylated HCA II. The identification of the HSA crystals was carried out by peptide mapping and mass spectrometry. HSA was shown to have crystallized as an NCS dimer in space group C2, with unit-cell parameters a = 150.9, b = 72.3, c = 91.3?Å, ? = 102.8°. The NCS dimer crystal structure is reported to 3.0?Å resolution, with a refined R cryst of 0.228. The structure is compared with the previously reported P212121 monomer structures and the crystal packing and dimer interface are discussed. PMID:16511271

Fisher, S. Zoë; Govindasamy, Lakshmanan; Tu, Chingkuang; Agbandje-McKenna, Mavis; Silverman, David N.; Rajaniemi, Hannu J.; McKenna, Robert

2006-01-01

134

Quantization of the optical phase space in terms of the group  

NASA Astrophysics Data System (ADS)

The problem of quantizing properly the canonical pair angle and action variables, and I, is almost as old as quantum mechanics itself and since decades an intensively debated but still unresolved issue in quantum optics. The present paper proposes a new approach to the problem, namely quantization in terms of the group SO(1,2): The crucial point is that the phase space %200%5C%7D%24%5Cend%7Bdocument%7D"> has the global structure (a simple cone) and cannot be quantized in the conventional manner. As the group SO(1,2) acts transitively, effectively and Hamilton-like on that space its irreducible unitary representations of the positive discrete series provide the appropriate quantum theoretical framework. The phase space has the conic structure of an orbifold . That structure is closely related to a Z2 gauge symmetry which corresponds to the center of a 2-fold covering of SO(1,2), the symplectic group . The basic variables on the phase space are the functions h0 = I , h1 = I cos and h2 = -I sin the Poisson brackets of which obey the Lie algebra . In the quantum theory they are represented by the self-adjoint Lie algebra generators K0, K1, and K2 of a unitary representation, where K0 has the spectrum {k + n, n = 0, 1, ...; k > 0}. A crucial prediction is that the classical Pythagorean relation h12 + h22 = h02 can be violated in the quantum theory. For each representation one can define three different types of coherent states the complex phases of which may be measured by means of the operators K1 and K2 alone without introducing any new phase operators! The SO(1,2) structure of optical squeezing and interference properties as well as that of the harmonic oscillator are analyzed in detail. The additional coherent states can be used for the introduction of (Husimi type) Q distributions and (Sudarshan-Glauber type) P representations of the density operator. The three operators K0, K1, and K2 are fundamental in the sense that one can construct composite position and momentum operators out of them! The new framework poses quite a number of fascinating experimental and theoretical challenges.

Kastrup, H. A.

2003-10-01

135

R. Bantges, C. Belotti, H. Brindley, J. Harries and D. Jabry Space and Atmospheric Physics Group, Imperial College London, UK.  

E-print Network

R. Bantges, C. Belotti, H. Brindley, J. Harries and D. Jabry Space and Atmospheric Physics Group. The mission concept represents a new phase in space based monitoring of climate, being specifically designed and monitoring of the critical climate processes that control the radiative balance of the Earth, including

136

PC Guia Online Pas: Portugal  

E-print Network

PC Guia Online País: Portugal Period.: Diária �mbito: Online Pag.: 1 de 3ID: 41187356 09 Multimodais Inteligentes do INESC-ID no contexto da rede de excelência europeia Games and Learning Alliance emprego em tecnologia #12;PC Guia Online País: Portugal Period.: Diária �mbito: Online Pag.: 2 de 3ID

Instituto de Sistemas e Robotica

137

Parallel computing on a PC Linux Cluster  

NASA Astrophysics Data System (ADS)

For numeric calculations we have used since 1999 a homogeneous parallel PC Linux cluster. We have build a system of eight dual Pentium III (600 MHz) nodes with Intel N 440BX motherboards. (total of 16 CPU-s and 4 GB of SDRAM on a homogeneous PC cluster). Each node has 9GB IBM Ultra Wide SCSI disk. The whole parallel system (including its private network) is protected against power failure by an APC Matrix UPS system providing backup energy for up to 60 minutes. The computers are stored in a grounded metal skelet. Nodes of the system are networked by a private 1-Gbit Ethernet network based on a 12 port 1-Gbit 3Com switch. We run several distributed applications on this supercomputer like the computation of the nuclear symplectic model, simulation of space plasmas and reconstruction of geologic profiles by inverse scattering method. We have seen enhanced performance when the calculation is distributed between as many as eight procesessors. However, for more than eight processors the performance saturates and there is little further gain. We build a new PC cluster based on four processor motherboards.

Travnicek, Pavel; Dytrych, T.; Hellinger, P.; Jasensky, V.; Soucek, J.

2001-06-01

138

Facilitated spin models in one dimension: A real-space renormalization group study  

NASA Astrophysics Data System (ADS)

We use a real-space renormalization group (RSRG) to study the low-temperature dynamics of kinetically constrained Ising chains (KCICs). We consider the cases of the Fredrickson-Andersen (FA) model, the East model, and the partially asymmetric KCIC. We show that the RSRG allows one to obtain in a unified manner the dynamical properties of these models near their zero-temperature critical points. These properties include the dynamic exponent, the growth of dynamical length scales, and the behavior of the excitation density near criticality. For the partially asymmetric chain, the RG predicts a crossover, on sufficiently large length and time scales, from East-like to FA-like behavior. Our results agree with the known results for KCICs obtained by other methods.

Whitelam, Stephen; Garrahan, Juan P.

2004-10-01

139

Nuclear safety policy working group recommendations on nuclear propulsion safety for the space exploration initiative  

NASA Technical Reports Server (NTRS)

An interagency Nuclear Safety Working Group (NSPWG) was chartered to recommend nuclear safety policy, requirements, and guidelines for the Space Exploration Initiative (SEI) nuclear propulsion program. These recommendations, which are contained in this report, should facilitate the implementation of mission planning and conceptual design studies. The NSPWG has recommended a top-level policy to provide the guiding principles for the development and implementation of the SEI nuclear propulsion safety program. In addition, the NSPWG has reviewed safety issues for nuclear propulsion and recommended top-level safety requirements and guidelines to address these issues. These recommendations should be useful for the development of the program's top-level requirements for safety functions (referred to as Safety Functional Requirements). The safety requirements and guidelines address the following topics: reactor start-up, inadvertent criticality, radiological release and exposure, disposal, entry, safeguards, risk/reliability, operational safety, ground testing, and other considerations.

Marshall, Albert C.; Lee, James H.; Mcculloch, William H.; Sawyer, J. Charles, Jr.; Bari, Robert A.; Cullingford, Hatice S.; Hardy, Alva C.; Niederauer, George F.; Remp, Kerry; Rice, John W.

1993-01-01

140

Synthesis, structural investigation, and solid-state properties of iodine-doped zirconium diphthalocyanine, [ZrPc2]I3.I2.  

PubMed

Crystals of iodine-doped zirconium(IV) diphthalocyanine, [ZrPc(2)]I(3).I(2) (where Pc = C(32)H(16)N(8)), were grown directly in the reaction of pure zirconium powder with phthalonitrile under a stream of iodine at 260 degrees C. [ZrPc(2)]I(3).I(2) crystallizes in the space group P2(1)/m (No. 11) of the monoclinic system with lattice parameters of a = 6.735(1), b = 25.023(5), and c = 17.440(3) A, beta = 99.43(3) degrees, and Z = 2. The crystals of [ZrPc(2)]I(3).I(2) are built up from two pseudo-monodimensional aggregates: one-electron-oxidized [ZrPc(2)](+) units; weak interacting triiodide I(3)(-) ions with neutral diiodine molecules. The I(3)(-) ions and neutral I(2) molecules in the crystal of [ZrPc(2)]I(3).I(2) have been also detected by Raman spectroscopy. The [ZrPc(2)](+) units form stacks along the a axis, while the polymeric...I(3)(-)...I(2)...I(3)(-)...I(2)(-)... zigzag chains are located in the crystal along the b axis, so both pseudo-monodimensional aggregates are perpendicular to each other. This arrangement is different from that found in the tetragonal crystals of [ZrPc(2)](I(3))(2/3) in which both monodimensional aggregates, i.e., the stacks of partially oxidized [ZrPc(2)](2/3+) units and chains of symmetric triiodide ions, are parallel. EPR experiment together with the X-ray single-crystal analysis clearly shown that oxidation of the diamagnetic ZrPc(2) complex by iodine is ligand centered and homogeneously affecting both phthalocyaninato rings of ZrPc(2); thus, the formal oxidation state of both Pc rings in [ZrPc(2)]I(3).I(2) is nonintegral (-1.5). The UV-vis spectrum of [ZrPc(2)] I(3).I(2) is very similar to the spectrum of unoxidized ZrPc(2) complex in the B Soret and Q spectral region. However, in the spectrum of [ZrPc(2)] I(3).I(2) one additional band at approximately 502 nm is observed, which indicates the existence of the one-electron-oxidized phthalocyaninato(-) radical ligand and is assigned to the electronic transition from a deeper level to the half-occupied HOMO level. The single-crystal electrical conductivity data show anisotropy and nonmetallic character in conductivity (d sigma/dT > 0). The charge transport mainly proceeds along the pseudo-monodimensional stacks of [ZrPc(2)](+) units. The relatively high conductivity along the stacks of one-electron-oxidized [ZrPc(2)](+) units results from the staggering orientation of Pc rings (rotation angle 45.0(2) degrees ) that leads to the short inter-ring C(alpha)(pyrrole)[bond]C(alpha)(pyrrole) contacts (2.839(3)-3.024(3) A). These C(alpha)-pyrrole atoms make appreciable contribution to the partially occupied pi-molecular orbital of Pc macrocycle and the greatest overlap of the HOMO orbitals that form the conduction band of partially oxidized molecular crystals. PMID:12767192

Janczak, Jan

2003-06-01

141

Quantum groups, roots of unity and particles on quantized Anti-de Sitter space  

SciTech Connect

Quantum groups in general and the quantum Anti-de Sitter group U{sub q}(so(2,3)) in particular are studied from the point of view of quantum field theory. The author shows that if q is a suitable root of unity, there exist finite-dimensional, unitary representations corresponding to essentially all the classical one-particle representations with (half) integer spin, with the same structure at low energies as in the classical case. In the massless case for spin {ge} 1, {open_quotes}naive{close_quotes} representations are unitarizable only after factoring out a subspace of {open_quotes}pure gauges{close_quotes}, as classically. Unitary many-particle representations are defined, with the correct classical limit. Furthermore, the author identifies a remarkable element Q in the center of U{sub q}(g), which plays the role of a BRST operator in the case of U{sub q}(so(2,3)) at roots of unity, for any spin {ge} 1. The associated ghosts are an intrinsic part of the indecomposable representations. The author shows how to define an involution on algebras of creation and anihilation operators at roots of unity, in an example corresponding to non-identical particles. It is shown how nonabelian gauge fields appear naturally in this framework, without having to define connections on fiber bundles. Integration on Quantum Euclidean space and sphere and on Anti-de Sitter space is studied as well. The author gives a conjecture how Q can be used in general to analyze the structure of indecomposable representations, and to define a new, completely reducible associative (tensor) product of representations at roots of unity, which generalizes the standard {open_quotes}truncated{close_quotes} tensor product as well as many-particle representations.

Steinacker, H [Univ. of California, Berkeley, CA (United States). Dept. of Physics

1997-05-23

142

Mathematical aspects of molecular replacement. III. Properties of space groups preferred by proteins in the Protein Data Bank.  

PubMed

The main goal of molecular replacement in macromolecular crystallography is to find the appropriate rigid-body transformations that situate identical copies of model proteins in the crystallographic unit cell. The search for such transformations can be thought of as taking place in the coset space ?\\G where ? is the Sohncke group of the macromolecular crystal and G is the continuous group of rigid-body motions in Euclidean space. This paper, the third in a series, is concerned with viewing nonsymmorphic ? in a new way. These space groups, rather than symmorphic ones, are the most common ones for protein crystals. Moreover, their properties impact the structure of the space ?\\G. In particular, nonsymmorphic space groups contain both Bieberbach subgroups and symmorphic subgroups. A number of new theorems focusing on these subgroups are proven, and it is shown that these concepts are related to the preferences that proteins have for crystallizing in different space groups, as observed in the Protein Data Bank. PMID:25727867

Chirikjian, G; Sajjadi, S; Toptygin, D; Yan, Y

2015-03-01

143

The Origin of OB Clusters: From 10 pc to 0.1 pc  

NASA Astrophysics Data System (ADS)

We observe the 1.2 mm continuum emission around the OB cluster-forming region G10.6-0.4, using the MAMBO-2 bolometer array of the IRAM 30 m telescope and the Submillimeter Array (SMA). Comparison of the Spitzer 24 ?m and 8 ?m images with our 1.2 mm continuum maps reveal an ionization front of an H II region, the photon-dominated layer, and several 5 pc scale filaments that follow the outer edge of the photon-dominated layer. The filaments, which are resolved in the MAMBO-2 observations, show regularly spaced parsec-scale molecular clumps, embedded with a cluster of dense molecular cores as shown in the SMA 0.87 mm observations. Toward the center of the G10.6-0.4 region, the combined SMA+IRAM 30 m continuum image reveals several parsec-scale protrusions. They may continue down to within 0.1 pc of the geometric center of a dense 3 pc scale structure, where a 200 M ? OB cluster resides. The observed filaments may facilitate mass accretion onto the central cluster-forming region in the presence of strong radiative and mechanical stellar feedback. Their filamentary geometry may also facilitate fragmentation. We did not detect any significant polarized emission at 0.87 mm in the inner 1 pc region with SMA.

Liu, Hauyu Baobab; Quintana-Lacaci, Guillermo; Wang, Ke; Ho, Paul T. P.; Li, Zhi-Yun; Zhang, Qizhou; Zhang, Zhi-Yu

2012-01-01

144

International Space Station Air Quality Assessed According to Toxicologically-Grouped Compounds  

NASA Technical Reports Server (NTRS)

Scores of compounds are found in the International Space Station (ISS) atmospheric samples that are returned to the Johnson Space Center Toxicology Laboratory for analysis. Spacecraft Maximum Allowable Concentrations (SMACs) are set with the view that each compound is present as if there were no other compounds present. In order to apply SMACs to the interpretation of the analytical data, the toxicologist must employ some method of combining the potential effects of the aggregate of compounds found in the atmospheric samples. The simplest approach is to assume that each quantifiable compound has the potential for some effect in proportion to the applicable SMAC, and then add all the proportions. This simple paradigm disregards the fact that most compounds have potential to adversely affect only a few physiological systems, and their effects would be independent rather than additive. An improved approach to dealing with exposure to mixtures is to add the proportions only for compounds that adversely affect the same physiological system. For example, toxicants that cause respiratory irritation are separated from those that cause neurotoxicity or cardio-toxicity. Herein we analyze ISS air quality data according to toxicological groups with a view that this could be used for understanding any crew symptoms occurring at the time of the sample acquisition. In addition, this approach could be useful in post-flight longitudinal surveys where the flight surgeon may need to identify post-flight, follow-up medical studies because of on-orbit exposures that target specific physiological systems.

James, John T.; Limero, Thomas F.; Beck, Steve; Cheng, Patti F.; deVera, Vanessa J.; Hand, Jennifer; Macatangay, Ariel

2010-01-01

145

International Space Station Air Quality Assessed According to Toxicologically-Grouped Compounds  

NASA Technical Reports Server (NTRS)

Scores of compounds are found in the International Space Station (ISS) atmospheric samples that are returned to the Johnson Space Center Toxicology Laboratory for analysis. Spacecraft Maximum Allowable Concentrations (SMACs) are set with the view that each compound is present as if there were no other compounds present. In order to apply SMACs to the interpretation of the analytical data, the toxicologist must employ some method of combining the potential effects of the aggregate of compounds found in the atmospheric samples. The simplest approach is to assume that each quantifiable compound has the potential for some effect in proportion to the applicable SMAC, and then add all the proportions. This simple paradigm disregards the fact that most compounds have potential to adversely affect only a few physiological systems, and their effects would be independent rather than additive. An improved approach to dealing with exposure to mixtures is to add the proportions only for compounds that adversely affect the same physiological system. For example, toxicants that cause respiratory irritation are separated from those that cause neurotoxicity or cardio-toxicity. Herein we analyze ISS air quality data according to toxicological groups with a view that this could be used for understanding any crew symptoms occurring at the time of the sample. In addition, this approach could be useful in post-flight longitudinal surveys where the flight surgeon may need to identify post-flight, follow-up medical studies because of on-orbit exposures that target specific physiological systems.

James, John T.; Limero, Tom; DeVera, Vanessa; Cheng, Patti; Hand, Jennifer; Macatangay, Ariel; Beck, Steve

2009-01-01

146

Outreach of Astronomy with emphasis to the Solar System by the Space group in Greece  

NASA Astrophysics Data System (ADS)

We have a long tradition in Space and Solar System outreach at the University of Athens (Space Group). We have contributed with many popular science articles in encyclopaedias (a total of some 200000 words), magazines and newspapers, public lectures around Greece and radio and TV programmes. We contribute in exhibitions for the public on many occasions (e.g. The British Exploration of the Planets, an exhibition organized by the British Council, at Eugenides Foundation and The Planetarium, where I prepared some 15 posters). We are preparing an outreach site of Astrophysics with sections for the planets, the exploration of the solar system and solar terrestrial relations. I am preparing several posters for the planets. We organize with the Hellenic Physical Union a series of Astrophysics Lectures at the University of Athens. Together with the Hellenic Physical Union we are planning to produce a theatrical play and CD or DVD concerning the planets. We have excellent collaboration with the amateur astronomers allover Greece and Cyprus. We organize, together with Physics or mathematics teachers in high schools several events related to astronomical observations (e.g. Venus transit, solar eclipe, astronomy nights). 1 We also organize popular science programmes in TV channels. I brief we consider Astronomy and especially the planetary system as a "Great Attractor" of pupil and the general public to science and we use it on every occasion for the benefit of the pupil and science. 2

Moussas, X.; Dialynas, K.; Babasides, G.; Fasoulopoulos, G.; Dimitropoulou, V.; Prassopoulos, D.; Kouphos, S.; Spandagos, E.; Strikis, J.

147

On the reflection type decomposition of the adjoint reduced phase space of a compact semisimple Lie group  

NASA Astrophysics Data System (ADS)

We consider a system with symmetries whose configuration space is a compact Lie group, acted upon by inner automorphisms. The classical reduced phase space of this system decomposes into connected components of orbit type subsets. To investigate hypothetical quantum effects of this decomposition one has to construct the associated costratification of the Hilbert space of the quantum system in the sense of Huebschmann. In the present paper, instead of the decomposition by orbit types, we consider the related decomposition by reflection types (conjugacy classes of reflection subgroups). These two decompositions turn out to coincide, e.g., for the classical groups SU(n) and Sp(n). We derive defining relations for reflection type subsets in terms of irreducible characters and discuss how to obtain from that the corresponding costratification of the Hilbert space of the system. To illustrate the method, we give explicit results for some low rank classical groups.

Hofmann, M.; Rudolph, G.; Schmidt, M.

2013-08-01

148

On the reflection type decomposition of the adjoint reduced phase space of a compact semisimple Lie group  

SciTech Connect

We consider a system with symmetries whose configuration space is a compact Lie group, acted upon by inner automorphisms. The classical reduced phase space of this system decomposes into connected components of orbit type subsets. To investigate hypothetical quantum effects of this decomposition one has to construct the associated costratification of the Hilbert space of the quantum system in the sense of Huebschmann. In the present paper, instead of the decomposition by orbit types, we consider the related decomposition by reflection types (conjugacy classes of reflection subgroups). These two decompositions turn out to coincide, e.g., for the classical groups SU(n) and Sp(n). We derive defining relations for reflection type subsets in terms of irreducible characters and discuss how to obtain from that the corresponding costratification of the Hilbert space of the system. To illustrate the method, we give explicit results for some low rank classical groups.

Hofmann, M. [Naturwissenschaftlich-Technische Fakultät, Universität Siegen, Walter-Flex-Str. 3, 57068 Siegen (Germany)] [Naturwissenschaftlich-Technische Fakultät, Universität Siegen, Walter-Flex-Str. 3, 57068 Siegen (Germany); Rudolph, G.; Schmidt, M. [Institut für Theoretische Physik, Universität Leipzig, Augustusplatz 10/11, 04109 Leipzig (Germany)] [Institut für Theoretische Physik, Universität Leipzig, Augustusplatz 10/11, 04109 Leipzig (Germany)

2013-08-15

149

Using Innovative Outliers to Detect Discrete Shifts in Dynamics in Group-Based State-Space Models  

Microsoft Academic Search

Outliers are typically regarded as data anomalies that should be discarded. However, dynamic or “innovative” outliers can be appropriately utilized to capture unusual but substantively meaningful shifts in a system's dynamics. We extend De Jong and Penzer's 1998 approach for representing outliers in single-subject state-space models to a group-based framework. The group-based model enables model predictions concerning the group as

Sy-Miin Chow; Ellen L. Hamaker; Jason C. Allaire

2009-01-01

150

Hubble Space Telescope Snapshot Search for Planetary Nebulae in Globular Clusters of the Local Group  

NASA Astrophysics Data System (ADS)

Single stars in ancient globular clusters (GCs) are believed incapable of producing planetary nebulae (PNs), because their post-asymptotic-giant-branch evolutionary timescales are slower than the dissipation timescales for PNs. Nevertheless, four PNs are known in Galactic GCs. Their existence likely requires more exotic evolutionary channels, including stellar mergers and common-envelope binary interactions. I carried out a snapshot imaging search with the Hubble Space Telescope (HST) for PNs in bright Local Group GCs outside the Milky Way. I used a filter covering the 5007 Å nebular emission line of [O iii], and another one in the nearby continuum, to image 66 GCs. Inclusion of archival HST frames brought the total number of extragalactic GCs imaged at 5007 Å to 75, whose total luminosity slightly exceeds that of the entire Galactic GC system. I found no convincing PNs in these clusters, aside from one PN in a young M31 cluster misclassified as a GC, and two PNs at such large angular separations from an M31 GC that membership is doubtful. In a ground-based spectroscopic survey of 274 old GCs in M31, Jacoby et al. found three candidate PNs. My HST images of one of them suggest that the [O iii] emission actually arises from ambient interstellar medium rather than a PN; for the other two candidates, there are broadband archival UV HST images that show bright, blue point sources that are probably the PNs. In a literature search, I also identified five further PN candidates lying near old GCs in M31, for which follow-up observations are necessary to confirm their membership. The rates of incidence of PNs are similar, and small but nonzero, throughout the GCs of the Local Group. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, and from the data archive at STScI, which are operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Bond, Howard E.

2015-04-01

151

Target selection and comparison of mission design for space debris removal by DLR's advanced study group  

NASA Astrophysics Data System (ADS)

Space debris is a growing problem. Models show that the Kessler syndrome, the exponential growth of debris due to collisions, has become unavoidable unless an active debris removal program is initiated. The debris population in LEO with inclination between 60° and 95° is considered as the most critical zone. In order to stabilize the debris population in orbit, especially in LEO, 5 to 10 objects will need to be removed every year. The unique circumstances of such a mission could require that several objects are removed with a single launch. This will require a mission to rendezvous with a multitude of objects orbiting on different altitudes, inclinations and planes. Removal models have assumed that the top priority targets will be removed first. However this will lead to a suboptimal mission design and increase the ?V-budget. Since there is a multitude of targets to choose from, the targets can be selected for an optimal mission design. In order to select a group of targets for a removal mission the orbital parameters and political constraints should also be taken into account. Within this paper a number of the target selection criteria are presented. The possible mission targets and their order of retrieval is dependent on the mission architecture. A comparison between several global mission architectures is given. Under consideration are 3 global missions of which a number of parameters are varied. The first mission launches multiple separate deorbit kits. The second launches a mother craft with deorbit kits. The third launches an orbital tug which pulls the debris in a lower orbit, after which a deorbit kit performs the final deorbit burn. A RoM mass and cost comparison is presented. The research described in this paper has been conducted as part of an active debris removal study by the Advanced Study Group (ASG). The ASG is an interdisciplinary student group working at the DLR, analyzing existing technologies and developing new ideas into preliminary concepts.

van der Pas, Niels; Lousada, Joao; Terhes, Claudia; Bernabeu, Marc; Bauer, Waldemar

2014-09-01

152

A New Nearby Candidate Star Cluster in Ophiuchus at d = 170 pc  

E-print Network

The recent discoveries of nearby star clusters and associations within a few hundred pc of the Sun, as well as the order of magnitude difference in the formation rates of the embedded and open cluster populations, suggests that additional poor stellar groups are likely to be found at surprisingly close distances to the Sun. Here I describe a new nearby stellar aggregate found by virtue of the parallel proper motions, similar trigonometric parallaxes, and consistent color-magnitude distribution of its early-type members. The 120 Myr-old group lies in Ophiuchus at $d$ $\\simeq$ 170 pc, with its most massive member being the 4th-magnitude post-MS B8II-III star $\\mu$ Oph. The group may have escaped previous notice due to its non-negligible extinction ($A_V$ $\\simeq$ 0.9 mag). If the group was born with a normal initial mass function, and the nine B- and A-type systems represent a complete system of intermediate-mass stars, then the original population was probably of order $\\sim$200 systems. The age and space motion of the new cluster are very similar to those of the Pleiades, $\\alpha$ Per cluster, and AB Dor Moving Group, suggesting that these aggregates may have formed in the same star-forming complex some $\\sim10^8$ yr ago.

Eric E. Mamajek

2006-09-04

153

Transformation of Air Quality Monitor Data from the International Space Station into Toxicological Effect Groups  

NASA Technical Reports Server (NTRS)

The primary reason for monitoring air quality aboard the International Space Station (ISS) is to determine whether air pollutants have collectively reached a concentration where the crew could experience adverse health effects. These effects could be near-real-time (e.g. headache, respiratory irritation) or occur late in the mission or even years later (e.g. cancer, liver toxicity). Secondary purposes for monitoring include discovery that a potentially harmful compound has leaked into the atmosphere or that air revitalization system performance has diminished. Typical ISS atmospheric trace pollutants consist of alcohols, aldehydes, aromatic compounds, halo-carbons, siloxanes, and silanols. Rarely, sulfur-containing compounds and alkanes are found at trace levels. Spacecraft Maximum Allowable Concentrations (SMACs) have been set in cooperation with a subcommittee of the National Research Council Committee on Toxicology. For each compound and time of exposure, the limiting adverse effect(s) has been identified. By factoring the analytical data from the Air Quality Monitor (AQM), which is in use as a prototype instrument aboard the ISS, through the array of compounds and SMACs, the risk of 16 specific adverse effects can be estimated. Within each adverse-effect group, we have used an additive model proportioned to each applicable 180-day SMAC to estimate risk. In the recent past this conversion has been performed using archival data, which can be delayed for months after an air sample is taken because it must be returned to earth for analysis. But with the AQM gathering in situ data each week, NASA is in a position to follow toxic-effect groups and correlate these with any reported crew symptoms. The AQM data are supplemented with data from real-time CO2 instruments aboard the ISS and from archival measurements of formaldehyde, which the AQM cannot detect.

James, John T.; Zalesak, Selina M.

2011-01-01

154

Detection vs. grouping thresholds for elements differing in spacing, size and luminance. An alternative approach towards the psychophysics of Gestalten.  

PubMed

Three experiments were performed to compare thresholds for the detection of non-uniformity in spacing, size and luminance with thresholds for grouping. In the first experiment a row of 12 black equi-spaced dots was used and the spacing after the 3rd, 6th, and 9th dot increased in random steps to determine the threshold at which the observer detected an irregularity in the size of the gaps. Thereafter, spacing in the same locations was increased further to find the threshold at which the observer perceived four groups of three dots each (triplets). In the second experiment, empty circles were used instead of dots and the diameter of the circles in the first and second triplet increased until the difference in size gave rise either to a detection or grouping response. In the third experiment, the dots in the second and fourth triplet were increased in luminance. The aim again was to compare the difference in brightness required for detection or grouping, respectively. Results demonstrate that the threshold for perceiving stimuli as irregularly spaced or dissimilar in size or brightness is much smaller than the threshold for grouping. In order to perceive stimuli as grouped, stimulus differences had to be 5.2 times (for dot spacing), 7.4 times (for size) and 6.6 times (for luminance) larger than for detection. Two control experiments demonstrated that the difference between the two kinds of thresholds persisted even when only two gaps were used instead of three and when gap position was randomized. PMID:20363241

Gori, Simone; Spillmann, Lothar

2010-06-11

155

Group Dynamics as a Critical Component of Successful Space Exploration: Conceptual Theory and Insights from the Biosphere 2 Closure Experiment  

NASA Astrophysics Data System (ADS)

As space exploration and eventually habitation achieves longer durations, successfully managing group dynamics of small, physically isolated groups will become vital. The paper summarizes important underlying research and conceptual theory and how these manifested in a well-documented example: the closure experiments of Biosphere 2. Key research breakthroughs in discerning the operation of small human groups comes from the pioneering work of W.R. Bion. He discovered two competing modalities of behavior. The first is the “task-oriented” or work group governed by shared acceptance of goals, reality-thinking in relation to time, resources and rational, and intelligent management of challenges presented. The opposing, usually unconscious, modality is what Bion called the “basic-assumption” group and alternates between three “group animal” groups: dependency/kill the leader; fight/flight and pairing. If not dealt with, these dynamics work to undermine and defeat the conscious task group’s goal achievement. The paper discusses crew training and selection, various approaches to structuring the work and hierarchy of the group, the importance of contact with a larger population through electronic communication and dealing with the “us-them” syndrome frequently observed between crew and Mission Control. The experience of the first two year closure of Biosphere 2 is drawn on in new ways to illustrate vicissitudes and management of group dynamics especially as both the inside team of biospherians and key members of Mission Control had training in working with group dynamics. Insights from that experience may help mission planning so that future groups in space cope successfully with inherent group dynamics challenges that arise.

Nelson, Mark; Allen, John P.

156

Computer (PC/Network) Coordinator.  

ERIC Educational Resources Information Center

This publication contains 22 subjects appropriate for use in a competency list for the occupation of computer (PC/network) coordinator, 1 of 12 occupations within the business/computer technologies cluster. Each unit consists of a number of competencies; a list of competency builders is provided for each competency. Titles of the 22 units are as…

Ohio State Univ., Columbus. Center on Education and Training for Employment.

157

D2PC sensitivity analysis  

SciTech Connect

The Chemical Hazard Prediction Model (D2PC) developed by the US Army will play a critical role in the Chemical Stockpile Emergency Preparedness Program by predicting chemical agent transport and dispersion through the atmosphere after an accidental release. To aid in the analysis of the output calculated by D2PC, this sensitivity analysis was conducted to provide information on model response to a variety of input parameters. The sensitivity analysis focused on six accidental release scenarios involving chemical agents VX, GB, and HD (sulfur mustard). Two categories, corresponding to conservative most likely and worst case meteorological conditions, provided the reference for standard input values. D2PC displayed a wide variety of sensitivity to the various input parameters. The model displayed the greatest overall sensitivity to wind speed, mixing height, and breathing rate. For other input parameters, sensitivity was mixed but generally lower. Sensitivity varied not only with parameter, but also over the range of values input for a single parameter. This information on model response can provide useful data for interpreting D2PC output.

Lombardi, D.P.

1992-08-01

158

Differentiation of PC12 Cells  

NSDL National Science Digital Library

This 3-week-long series of collaborative laboratory exercises explores how to use a cultured cell system (PC12 cells) to study signaling pathways involved in cellular differentiation. The laboratory would be useful in a neurobiology or cell biology course for advanced undergraduate students. The background and details for performing the lab are provided along with suggestions for assessing student performance and understanding.

Elizabeth M. Adler (American Association for the Advancement of Science; Associate Editor of Science's STKE REV)

2006-09-05

159

LDEF meteoroid and debris special investigation group investigations and activities at the Johnson Space Center  

NASA Technical Reports Server (NTRS)

Since the return of the Long Duration Exposure Facility (LDEF) in January, 1990, members of the Meteoroid and Debris Special Investigation Group (M&D SIG) at the Johnson Space Center (JSC) in Houston, Texas have been examining LDEF hardware in an effort to expand the knowledge base regarding the low-Earth orbit (LEO) particulate environment. In addition to the various investigative activities, JSC is also the location of the general Meteoroid & Debris database. This publicly accessible database contains information obtained from the various M&D SIG investigations, as well as limited data obtained by individual LDEF Principal Investigators. LDEF exposed approximately 130 m(exp 2) of surface area to the LEO particulate environment, approximately 15.4 m(exp 2) of which was occupied by structural frame components (i.e., longerons and intercoastals) of the spacecraft. The data reported here was obtained as a result of detailed scans of LDEF intercoastals, 68 of which reside at JSC. The limited amount of data presently available on the A0178 thermal control blankets was reported last year and will not be reiterated here. The data presented here are limited to measurements of crater diameters and their frequency of occurrence (i.e., flux).

See, Thomas H.; Warren, Jack L.; Zolensky, Michael E.; Sapp, Clyde A.; Bernhard, Ronald P.; Dardano, Claire B.

1995-01-01

160

Hubble Space Telescope Snapshot Search for Planetary Nebulae in Globular Clusters of the Local Group  

E-print Network

Single stars in ancient globular clusters (GCs) are believed incapable of producing planetary nebulae (PNe), because their post-asymptotic-giant-branch evolutionary timescales are slower than the dissipation timescales for PNe. Nevertheless, four PNe are known in Galactic GCs. Their existence likely requires more exotic evolutionary channels, including stellar mergers and common-envelope binary interactions. I carried out a snapshot imaging search with the Hubble Space Telescope (HST) for PNe in bright Local Group GCs outside the Milky Way. I used a filter covering the 5007 A nebular emission line of [O III], and another one in the nearby continuum, to image 66 GCs. Inclusion of archival HST frames brought the total number of extragalactic GCs imaged at 5007 A to 75, whose total luminosity slightly exceeds that of the entire Galactic GC system. I found no convincing PNe in these clusters, aside from one PN in a young M31 cluster misclassified as a GC, and two PNe at such large angular separations from an M31 ...

Bond, Howard E

2015-01-01

161

Overview of the Space Propulsion Synergy Group (SPSG) strategic planning support efforts for earth to orbit transportation  

NASA Astrophysics Data System (ADS)

An essential requirement of a successful space program is the assurance of a safe affordable routine access to space. In view of this, a national organization known as the Space Propulsion Synergy Group (SPSG) has been directed for the past two years toward supporting strategic planning for earth-to-orbit space transportation and propulsion systems. This paper presents a short description of the approach the SPSG followed in their space transportation and propulsion systems strategic planning support activities. The SPSG study emphasized the identification of the transportation systems users/customers and the characteristics of attributes most valued by them in earth-to-LEO payload transportation services. The study initiated the process known as Quality Function Deployment to ensure that the customer/user real requirements and needs are properly addressed and that the transportation system concepts advocated had the greatest probability of satisfying the custosmer's requirements and desired attributes.

Dankhoff, Walter F.; Hope, William P., Jr.

1993-06-01

162

Rigidity of automorphism groups of invariant domains in homogeneous Stein spaces  

NASA Astrophysics Data System (ADS)

For a large class of Stein manifolds which are homogeneous under a complex reductive Lie group, we prove a rigidity property of the automorphism groups of domains invariant with respect to a compact form of this complex group.

Deng, F.; Zhou, X. Yu

2014-02-01

163

Creating Social Spaces to Tackle AIDS-Related Stigma: Reviewing the Role of Church Groups in Sub-Saharan Africa  

Microsoft Academic Search

An expanding body of literature explores the role of African church groups in facilitating or hindering the support of people\\u000a living with AIDS and challenging or contributing to HIV\\/AIDS-related stigma. Treating church groups as social spaces in which\\u000a HIV\\/AIDS-related stigma may potentially be challenged, we systematically review this literature, identifying five themes that\\u000a highlight the complex and contradictory role of

C. Campbell; M. Skovdal; A. Gibbs

2011-01-01

164

Global space-group optimization problem: Finding the stablest crystal structure without constraints  

NASA Astrophysics Data System (ADS)

Finding the most stable structure of a solid is one of the central problems in condensed matter physics. This entails finding both the lattice type (e.g., fcc, bcc, and orthorhombic) and (for compounds) the decoration of the lattice sites by atoms of types A , B , etc. (“configuration”). Most approaches to this problem either assumed that both lattice type and configuration are known, optimizing instead the cell volume and performing local relaxation. Other approaches assumed that the lattice type is known, searching for the minimum-energy decoration. We present here an approach to the global space-group optimization (GSGO) problem, i.e., the problem of predicting both the lattice structure and the atomic configuration of a crystalline solid. This search method is based on an evolutionary algorithm within which a population of crystal structures is evolved through mating and mutation operations, improving the population by substituting the highest total-energy structures with new ones. The crystal structures are not represented by bit strings as in conventional genetic algorithms. Instead, the evolutionary search is performed directly on the atomic positions and the unit-cell vectors after a similarity transformation is applied to bring structures of different unit-cell shapes to a common basis. Following this transformation, we can define a crossover operation that treats, on the same footing, structures with different unit-cell shapes. Once a new structure has been generated by mating or mutation, it is fully relaxed to the closest local total-energy minimum. We applied our procedure for the GSGO in the context of pseudopotential total-energy calculations to the semiconductor systems Si, SiC, and GaAs and to the metallic alloy AuPd with composition Au8Pd4 . Starting from random unit-cell vectors and random atomic positions, the present search procedure found for all semiconductor systems studied the correct lattice structure and configuration. In the case of Au8Pd4 , the search retrieved the correct underlying fcc lattice, but energetically closely spaced (˜2meV/at.) alloy configurations were not resolved. This approach to GSGO opens the way to predicting unsuspected structures by direct optimization using, in the cases noted above, an order of 100 total-energy ab initio calculations.

Trimarchi, Giancarlo; Zunger, Alex

2007-03-01

165

Mapping of the oat crown rust resistance gene Pc91.  

PubMed

Crown rust is an important disease of oat caused by Puccinia coronata Corda f. sp. avenae Eriks. Crown rust is efficiently and effectively managed through the development of resistant oat varieties. Pc91 is a seedling crown rust resistance gene that is highly effective against the current P. coronata population in North America. The primary objective of this study was to develop DNA markers linked to Pc91 for purposes of marker-assisted selection in oat breeding programs. The Pc91 locus was mapped using a population of F7-derived recombinant inbred lines developed from the cross 'CDC Sol-Fi'/'HiFi' made at the Crop Development Centre, University of Saskatchewan. The population was evaluated for reaction to P. coronata in field nurseries in 2008 and 2009. Pc91 mapped to a linkage group consisting of 44 Diversity Array Technology (DArT) markers. DArTs were successfully converted to sequence characterized amplified region (SCAR) markers. Five robust SCARs were developed from three non-redundant DArTs that co-segregated with Pc91. SCAR markers were developed for different assay systems, such that SCARs are available for agarose gel electrophoresis, capillary electrophoresis, and Taqman single nucleotide polymorphism detection. The SCAR markers accurately postulated the Pc91 status of 23 North American oat breeding lines. PMID:20862449

McCartney, C A; Stonehouse, R G; Rossnagel, B G; Eckstein, P E; Scoles, G J; Zatorski, T; Beattie, A D; Chong, J

2011-02-01

166

The orthogonal projections with respect to a periodic continuous unitary representation of the group (R,+) on a complex Hilbert space  

NASA Astrophysics Data System (ADS)

In this work, a family {Pn?}n?Z of orthogonal projections on a complex Hilbert space H is defined by means of a periodic continuous unitary representation ? of the topological group (R,+) on H, and some properties of this family are given.

Öztürk, Seda

2014-08-01

167

The meteor year of the Meteor Research Group of the European Space Agency's Research and Scientific Support Department  

Microsoft Academic Search

A lot of activities took place in 2007 at the Meteor Research Group (MRG) of the European Space Agency's (ESA) Research and Scientific Support Department (RSSD). Both special observing campaigns as well as continuous observations were performed, mainly with intensified video cameras, but also with still CCD cameras. Over 1400 meteors were observed; about 150 meteors were observed from more

D. V. Koschny; J. McAuliffe; G. Barentsen; F. C. M. Bettonvil; J. P. Hatton; F. Lowiessen; J. J. Zender

2008-01-01

168

Ultraviolet-Optical Space Astronomy Beyond HST Conference (Origins Conference and UV-Optical Working Group Support)  

NASA Technical Reports Server (NTRS)

This grant supported three major activities, from 1997-2001. (1) Origins Conference. The funds from this grant were used, initially, to support a Conference on "Origins", held May 19-23, 1997 at Estes Park, CO and attended by a wide range of astronomers, planetary scientists, and astrobiologists. The scientific proceedings of this meeting were published in 1998 by the Astronomical Society of the Pacific: "Origins" (1998) "Proceedings of the International Origins Conference". (2) UV-Optical Space Astronomy. Conference Additional funds provided by the NASA Office of Space Science were used to support a meeting held August 5-7, 1998 at Boulder, CO and attended by ultraviolet and optical astronomers and instrumentalists interested in a UV-O successor to the Hubble Space Telescope. The scientific proceedings of this meeting were published in 1999: "Ultraviolet-Optical Space Astronomy Beyond the Hubble Space Telescope" (1999), NASA provided funds and commissioned the UVOWG (Ultraviolet-Optical Working Group), charged with recommending a set of fundamental scientific problems and new space missions in the UV/Optical wavelength bands. The working group was chaired by J. M. Shull, and included ten other astrophysicists. Their report was published as a "White Paper" (Nov. 1999) entitled "The Emergence of the Modern Universe: Tracing the Cosmic Web" available. The results of this report were used in the NASA Strategic Planning ("Roadmap") exercise and by the NRC Astronomy/Astrophysics Decade Committee.

Shull, J. Michael; Morse, Jon

2001-01-01

169

Grouping  

NSDL National Science Digital Library

This interactive Flash applet models the measurement interpretation of division. A child or teacher chooses a total number of objects and a divisor representing the size of equal groups. The applet allows the user to move the objects into equal groups and links the process to jumps on a number line. The applet can be used to introduce children to remainders and to reinforce the language and notation of division. It works well on an interactive white board or projector. A teacher's guide to this collection of applets is cataloged separately.

2006-01-01

170

Proceedings of the Space Shuttle Sortie Workshop. Volume 2: Working group reports  

NASA Technical Reports Server (NTRS)

Details are presented on the mission planning progress in each of the working paper reports. The general topics covered are the following: space technology; materials processing and space manufacturing; communications and navigation; earth and ocean physics; oceanography; earth resources and surface environmental quality; meteorology and atmospheric environmental quality; life sciences; atmospheric and space physics; solar physics; high energy cosmic rays; X-ray and gamma ray astronomy; ultraviolet-optical astronomy; planetary astronomy; and infrared astronomy.

1972-01-01

171

The Carina-Near Moving Group  

E-print Network

We identify a group of ~20 co-moving, mostly southern hemisphere, ~200 Myr old stars near Earth. Of the stars likely to be members of this Carina-Near Moving Group, in either its nucleus (~30 pc from Earth) or surrounding stream, all but 3 are plausible members of a multiple star system. The nucleus is (coincidentally) located quite close to the nucleus of the AB Doradus moving group notwithstanding that the two groups have substantially different ages and Galactic space motions, UVW.

B. Zuckerman; M. S. Bessell; Inseok Song; S. Kim

2006-09-01

172

Influence of PC superplasticizers on tricalcium silicate Sylvie Pourchet*1  

E-print Network

to be due to the nucleation-growth of calcium silicate hydrates (C-S-H) resulting from tricalcium silicateInfluence of PC superplasticizers on tricalcium silicate hydration Sylvie Pourchet*1 , Cédric with variations of content of anionic groups was studied on pure tricalcium silicate hydration. The hydration

Boyer, Edmond

173

Time-course of hemispheric preference for processing contralateral relevant shapes: P1pc, N1pc, N2pc, N3pc  

PubMed Central

A most sensitive and specific electrophysiological indicator of selective processing of visual stimuli is the N2pc component. N2pc is a negative EEG potential peaking 250 ms after stimulus onset, recorded from posterior sites contralateral to relevant stimuli. Additional deflections preceding or following N2pc have been obtained in previous studies, possibly produced by specific stimulus features or specific prime-target sequences. To clarify the entire time-course of the contralateral- ipsilateral (C-I) difference recorded from the scalp above visual cortex in response to left-right pairs of targets and distracters, C-I differences were here compared between two types of stimuli and between stimuli that were or were not preceded by masked neutral primes. The C-I difference waveform consisted of several peaks, termed here P1pc (60-100 ms after target onset), N1pc (120-160 ms), N2pc (220-280 ms), and N3pc (360-400 ms). Being markedly enhanced when stimuli were preceded by the neutral primes, P1pc may indicate a response to stimulus change. Also, when stimuli were primed, N2pc reached its peak earlier, thereby tending to merge with N1pc. N3pc seemed to increase when target discrimination was difficult. N1pc, N2pc, and N3pc appear as three periods of one process. N3pc probably corresponds to L400 or SPCN as described in other studies. These observations suggest that the neurophysiological basis of stimulus-driven focusing of attention on target stimuli is a process that lasts for hundreds of milliseconds, with the relevant hemisphere being activated in an oscillating manner as long as required by the task. PMID:22419963

Verleger, Rolf; ?urawska vel Grajewska, Blandyna; Ja?kowski, Piotr

2012-01-01

174

Metric entropy of homogeneous spaces and Finsler geometry of classical Lie groups  

Microsoft Academic Search

For a (compact) subset $K$ of a metric space and $\\\\varepsilon > 0$, the {\\\\em\\u000acovering number} $N(K , \\\\varepsilon )$ is defined as the smallest number of\\u000aballs of radius $\\\\varepsilon$ whose union covers $K$. Knowledge of the {\\\\em\\u000ametric entropy}, i.e., the asymptotic behaviour of covering numbers for\\u000a(families of) metric spaces is important in many areas of

Stanislaw J. Szarek

1997-01-01

175

75 FR 62002 - Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350...  

Federal Register 2010, 2011, 2012, 2013, 2014

...in the Airworthiness Limitations Section (ALS). For PC-6 models other than B2-H2 and B2- H4, no ALS at all is included in the AMM. With the latest...models other than B2-H2 and B2-H4, a new ALS document has been implemented as well....

2010-10-07

176

Group dynamics in a long-term blind endeavor on Earth: An analog for space missions (Lewis & Clark Expedition group dynamic analysis)  

NASA Astrophysics Data System (ADS)

In 1803, President Thomas Jefferson set fourth a military expedition led by Captains M. Lewis and W. Clark (Lewis and Clark Expedition) on an exploration that would become an everlasting part of US national history and pride. Looking back at the events of this exploration, there are many similarities to the experiences future human space explorers will face as we look to colonize the Moon and travel to Mars and beyond (NASA Vision for Space Exploration, 2004): The Lewis and Clark Expedition lasted almost three years and involved a crew of 43 men traveling up the Missouri River to explore the unknown lands and a possible water route to the Pacific Ocean; The Expedition took place far away from customary comfortable environments known to European settlers in the early 18th century; The Expedition involved a remotely confined high-perceived risk environment with high levels of uncertainty providing stresses and every day challenges for the crew; Supplies brought on the mission were limited (mainly a mass/weight issue rather than cost), therefore the discovery and use of environmental resources (In-Situ Resource Utilization approach, including info-resources to mitigate uncertainty) was necessary for crew survival. The environments astronauts will encounter in space and on the Moon and Mars due to high risk and uncertainty will be in many aspects similar to what Lewis and Clark's crew experienced, as environments will be hostile and unforgiving if problems arise and aren't resolved quickly. The analysis provided in this research paper is relevant because the Lewis and Clark Expedition needed to move extensively and with minimal supplies. Polar remote settings, which were analyzed extensively, were different from this expedition due to the fact that these missions did not encompass extensive movement of crew facilities and supplies and were more like space missions orbiting the Earth. Using past space station results of performance on orbit in correlation with a suggested distinguishable mission phase model, the Lewis and Clark Expedition will be analyzed for similarities to these space findings. Factors of consideration in support of this analysis involve an understanding of the leadership qualities of Lewis and Clark (and relations established and maintained with one another), the selection and diversity of their crew, and the group dynamics that were developed and maintained so carefully during the expedition. With this knowledge and understanding one can gain enormous insights useful in the planning and preparation for future long-duration space exploratory missions with high level of autonomy, mobility, minimal primary life support supply and high dependence on material re-circulation and In-Situ Resource Utilization approach.

Allner, M.; Rygalov, V.

2008-12-01

177

Roars of black howler monkeys (Alouatta caraya): evidence for a function in inter-group spacing  

E-print Network

) Summary Loud calls can be expected to play an important role in the lives of howler monkeys, given-group encounters and extreme weather events triggered calling. Roars were given throughout the home range range of the study group, simulating invasions, or in border areas. In response to simulated invasions

178

SELECTION RULES FOR THE DOUBLE SPACE GROUP O1h H. KUNERT, J. POPENDA  

E-print Network

, is represented by several ionic crystals, including CsCI, CsBr, CsI, RbCI, TICI, TIBr, several compounds, is the structure of numerous ternary compounds where the molecules contain a transition metal and three oxygen de représentations irréductibles du groupe double O1h (groupe de symétrie de la structure cubique

Paris-Sud XI, Université de

179

SI PC104 Performance Test Report  

SciTech Connect

The Spectral Instruments (SI) PC104 systems associated with the SI-1000 CCD camera exhibited intermittent power problems during setup, test and operations which called for further evaluation and testing. The SI PC104 System is the interface between the SI-1000 CCD camera and its associated Diagnostic Controller (DC). As such, the SI PC104 must be a reliable, robust system capable of providing consistent performance in various configurations and operating conditions. This SI PC104 system consists of a stackable set of modules designed to meet the PC104+ Industry Standard. The SI PC104 System consists of a CPU module, SI Camera card, Media converter card, Video card and a I/O module. The root cause of power problems was identified as failing solder joints at the LEMO power connector attached to the SI Camera Card. The recommended solution was to provide power to the PC104 system via a PC104+ power supply module configured into the PC104 stack instead of thru the LEMO power connector. Test plans (2) were developed to test SI PC104 performance and identify any outstanding issues noted during extended operations. Test Plan 1 included performance and image acquisition tests. Test Plan 2 verified performance after implementing recommendations. Test Plan 2 also included verifying integrity of system files and driver installation after bootup. Each test plan was implemented to fully test against each set of problems noted. Test Plan presentations and Test Plan results are attached as appendices. Anticipated test results will show successful operation and reliable performance of the SI PC104 system receiving its power via a PC104 power supply module. A SI PC104 Usage Recommendation Memo will be sent out to the SI PC104 User Community. Recommendation memo(s) are attached as appendices.

Montelongo, S

2005-12-16

180

Preliminary Experiences with a Tablet PC Based System to Support Active Learning in Computer Science Courses  

E-print Network

Preliminary Experiences with a Tablet PC Based System to Support Active Learning in Computer. We have developed such a system as an extension to Classroom Presenter [2], a Tablet PC-based presentation system. In our system students (or groups of students) are equipped with tablet computers

Anderson, Richard

181

Space station needs attributes and architectural options study costing working group briefing  

NASA Technical Reports Server (NTRS)

Individuals in the United States who understand the promise of materials processing in space and who also are senior technical personnel associated with commercial firms that process materials: (1) endorsed the concept of a space station as a desirable national asset; (2) stated that a commercial MPS research program is mandatory to extend commericalization of space for materials processing; and (3) described in general terms a national research laboratory and free flying facilities that are needed. Participants agreed that industry R&D is motivated largely by market pull rather than by technology push, that initial interest is low-g materials research; and that to farther, commercial market assurance (a salable product) is a must.

1983-01-01

182

Pathway Controlled Penetration (PcP)  

SciTech Connect

The technical approach employs advanced computational simulation tools to demonstrate how current assets can destroy RWK-RFI-12-0001's HDBT, a tunnel complex with two portals built into the base of a granite mountain. The granite over layer is assumed to be 60 meters thick over both portals and 80 meters over the facility's mission space. Key S&T is the completed development of a highly innovative viscoplastic fracture material model, 3D parallel gas-fracture capabilities into FDEM, and a stochastic handling of the material properties. Phase I - Develop and validate code simulation tools: (1) develop, incorporate and validate AZ-Frac material model for granite; and (2) Develop and incorporate gas-driven-fracture modeling into LANL's FDEM MUNROU code; (3) Develop and incorporate stochastic features into FDEM modeling. Phase II - Conduct PcP analysis on above HDBT: (1) Acquire HDBT design data, develop simulation model; and (2) Evaluate and select most promising defeat alternative. Phase III - Deliver code, train Service target analysts, and conduct simulations against real world HDBTs. PcP uses advanced computer simulations to enhance HDBT functional defeat efforts. Newly developed material models that account for fractural energy coupled with the finite discrete element methodology (FDEM) will provide targeting packages that will create penetration avenues for current or future lethality options. This novel computational approach requires full 3D geologic and structure characterization as well as significant high performance computing capabilities. The goal is to distinctively alter the targeting paradigm by leveraging critical DoD assets along with insitu geologic strata. In other words, assets will utilize underground rock structure to their benefit by creating rubbilization zones that will allow pathway controlled penetration.

Knight, Earl E. [Los Alamos National Laboratory; Rougier, Esteban [Los Alamos National Laboratory; Zubelewicz, Aleksander [Los Alamos National Laboratory

2012-08-29

183

Low cost PC based scanning Kelvin probe  

NASA Astrophysics Data System (ADS)

We have developed a novel, low cost, scanning Kelvin probe (SKP) system that can measure work function (wf) and surface potential (sp) topographies to within 1 meV energy resolution. The control and measurement subcomponents are PC based and incorporate a flexible user interface, permitting software control of major parameters and allowing easy user implementation via automatic setup and scanning procedures. We review the mode of operation and design features of the SKP including the digital oscillator, the compact ambient voice-coil head-stage, and signal processing techniques. This system offers unique tip-to-sample spacing control (to within 40 nm) which provides a method of simultaneously imaging sample height topographies and is essential to avoid spurious or "apparent" wf changes due to scanning-induced spacing changes. We illustrate SKP operation in generating high resolution wf/sp profiles of metal interfaces (as a tip characterization procedure) and operational electronic devices. The SKP potentially has a very wide range of applications ranging from semiconductor quality control thin film and surface analyses to corrosion and biopotential imaging.

Baikie, I. D.; Estrup, P. J.

1998-11-01

184

SPALENDAR: Visualizing a Group's Calendar Events over a Geographic Space on a Public Display  

E-print Network

Science, University of Calgary 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada xiangchen's calendar events as spatiotemporal activities occurring over a geographic space animated over time, all animates people's past, present and forthcoming movements between event locations as well as their static

Greenberg, Saul

185

SPALENDAR: Visualizing a Group's Calendar Events over a Geographic Space on a Public Display  

E-print Network

at a small size, or even completely hidden. Event details may not even be visible until one opens or drills Science, University of Calgary 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada xiangchen's calendar events as spatiotemporal activities occurring over a geographic space animated over time, all

Greenberg, Saul

186

Evaluating a Safe Space Training for School Counselors and Trainees Using a Randomized Control Group Design  

ERIC Educational Resources Information Center

School counselors need to advocate and act as an ally for all students. Safe Space, a training designed to facilitate competency for working with and serving LGBTQ youth (i.e., LGBTQ competency), has received increased attention in the field of school counseling. However, limited empirical support exists for training interventions such as Safe…

Byrd, Rebekah; Hays, Danica G.

2014-01-01

187

INTERNATIONAL CONFERENCE ON COMPOSITE MATERIALS Polycarbonate (PC) is widely used in aerospace  

E-print Network

in aerospace applications, such as airplane windows and space suit helmets due to its superior mechanical optical transparency. It is expected that reinforced PC nanocomposite will make inroads into space Introduction In a manned space activity, a big shift from government to private companies is occurring all over

Guo, John Zhanhu

188

PC/104 Embedded IOCs at Jefferson Lab  

SciTech Connect

Jefferson Lab has developed embedded IOCs based on PC/104 single board computers (SBC) for low level control systems. The PC/104 IOCs run EPICS on top of the RTEMS operating system. Two types of control system configurations are used in different applications, PC/104 SBC with commercial PC/104 I/O cards and PC/104 SBC with custom designed FPGA-based boards. RTEMS was built with CEXP shell to run on the PC/104 SBC. CEXP shell provides the function of dynamic object loading, which is similar to the widely used VxWorks operating system. Standard software configurations were setup for PC/104 IOC application development to provide a familiar format for new projects as well as ease the conversion of applications from VME based IOCs to PC/104 IOCs. Many new projects at Jefferson Lab are going to employ PC/104 SBCs as IOCs and some applications have already been running them for accelerator operations. The PC/104 - RTEMS IOC provides a free open source Real-Time Operating System (RTOS), low cost/maintenance, easily installed/ configured, flexible, and reliable solution for accelerator control and 12GeV Upgrade projects.

Jianxun Yan, Trent Allison, Sue Witherspoon, Anthony Cuffe

2009-10-01

189

Flexible missile autopilot design studies with PC-MATLAB/386  

NASA Technical Reports Server (NTRS)

Development of a responsive, high-bandwidth missile autopilot for airframes which have structural modes of unusually low frequency presents a challenging design task. Such systems are viable candidates for modern, state-space control design methods. The PC-MATLAB interactive software package provides an environment well-suited to the development of candidate linear control laws for flexible missile autopilots. The strengths of MATLAB include: (1) exceptionally high speed (MATLAB's version for 80386-based PC's offers benchmarks approaching minicomputer and mainframe performance); (2) ability to handle large design models of several hundred degrees of freedom, if necessary; and (3) broad extensibility through user-defined functions. To characterize MATLAB capabilities, a simplified design example is presented. This involves interactive definition of an observer-based state-space compensator for a flexible missile autopilot design task. MATLAB capabilities and limitations, in the context of this design task, are then summarized.

Ruth, Michael J.

1989-01-01

190

Learning in Large Learning Spaces: The Academic Engagement of a Diverse Group of Students  

ERIC Educational Resources Information Center

Teaching larger groups of students is a growing phenomenon in HE and this brings with it its own challenges, not least for the students themselves but also for their lecturers. Demographic factors as well as the experiences that characterise us as individuals will impact upon our ability to learn. The pilot study reported here considered the…

Hunt, Clive

2012-01-01

191

Creating Spaces for Critical Transformative Dialogues: Legitimising Discussion Groups as Professional Practice  

ERIC Educational Resources Information Center

Focussed dialogue (as lived and living practices) can have a powerful role in renewing professional practice, advancing its sustainability and development as administrative and political systems colonise the practices of teachers and teacher educators. However, participating in discussion groups for many teachers, including those in academia, is…

Edwards-Groves, Christine J.

2013-01-01

192

Time and space optimization for processing groups of multi-dimensional scientific queries  

Microsoft Academic Search

Data analysis applications in areas as diverse as remote sensing and telepathology require operating on and processing very large datasets. For such applications to execute efficiently, careful attention must be paid to the storage, retrieval, and manipulation of the datasets. This paper addresses the optimizations performed by a high performance database system that processes groups of data analysis requests for

Suresh Aryangat; Henrique Andrade; Alan Sussman

2004-01-01

193

Deep neck space abscesses of dental origin: the impact of Streptococcus group Milleri.  

PubMed

In recent years, there has been rising interest in Streptococcus group Milleri (SM) because high mortality rates have been related to it. In case of deep neck infections (DNI), whatever the origin, mortality rates as high as 26% were reported. But there are no data available for DNI with SM of purely dental origin. The aim of our article was to describe and analyse DNI of purely dental origin involving on one hand SM and on the other hand infections without presence of SM. We compared these two groups and statistically investigated if there were differences in clinical presentation (age, mouth opening, length of hospital stay, laboratory parameters) or clinical behaviour (re-operation, re-hospitalisation, secondary osteomyelitis, stay at intensive care, length of antibiotic treatment, presence of resistances against antibiotics, incapacity to work). For this, we retrospectively searched medical records of our institution for all purulent DNI treated from 2004 till 2012. We found 81 patients meeting all inclusion criteria. Thirty-four patients had involvement of SM, 47 did not. The only statistically significant difference between the SM group and the non-SM group was the length of incapacity to work. All other parameters were non-significant. Furthermore, there were no fatalities. In conclusion, the clinical importance of this article is that patients with deep neck abscesses of purely dental origin involving SM do not need more or different care when compared to all other DNI of dental origin. PMID:24241360

Terzic, Andrej; Scolozzi, Paolo

2014-10-01

194

Plant population and row spacing effects on maturity group III soybean  

Technology Transfer Automated Retrieval System (TEKTRAN)

Maturity group IV and V soybean produced in the upper mid-southern states of Kentucky, Tennessee, eastern Mississippi, and northern Alabama are primarily nonirrigated due to rolling uplands, highly erodible soils, and small fields common to the region. Sole reliance on rainfall and the coinciding o...

195

AMPS/PC - AUTOMATIC MANUFACTURING PROGRAMMING SYSTEM  

NASA Technical Reports Server (NTRS)

The AMPS/PC system is a simulation tool designed to aid the user in defining the specifications of a manufacturing environment and then automatically writing code for the target simulation language, GPSS/PC. The domain of problems that AMPS/PC can simulate are manufacturing assembly lines with subassembly lines and manufacturing cells. The user defines the problem domain by responding to the questions from the interface program. Based on the responses, the interface program creates an internal problem specification file. This file includes the manufacturing process network flow and the attributes for all stations, cells, and stock points. AMPS then uses the problem specification file as input for the automatic code generator program to produce a simulation program in the target language GPSS. The output of the generator program is the source code of the corresponding GPSS/PC simulation program. The system runs entirely on an IBM PC running PC DOS Version 2.0 or higher and is written in Turbo Pascal Version 4 requiring 640K memory and one 360K disk drive. To execute the GPSS program, the PC must have resident the GPSS/PC System Version 2.0 from Minuteman Software. The AMPS/PC program was developed in 1988.

Schroer, B. J.

1994-01-01

196

An HI survey of the Centaurus and Sculptor Groups - Constraints on the space density of low mass galaxies  

E-print Network

We present results of two 21-cm HI surveys performed with the Australia Telescope Compact Array in the nearby Centaurus A and Sculptor galaxy groups. These surveys are sensitive to compact HI clouds and galaxies with HI masses as low as 3E+06 Msun, and are therefore among the most sensitive extragalactic HI surveys to date. The surveys consist of sparsely spaced pointings that sample approximately 2% of the groups' area on the sky. We detected previously known group members, but we found no new HI clouds or galaxies down to the sensitivity limit of the surveys. If the HI mass function had a faint end slope of alpha = 1.5 below M_{HI} = 10^{7.5} Msun in these groups, we would have expected ~3 new objects. Cold dark matter theories of galaxy formation predict the existence of a large number low mass DM sub-halos that might appear as tiny satellites in galaxy groups. Our results support and extend similar conclusions derived from previous HI surveys that a HI rich population of these satellites does not exist.

W. J. G. de Blok; M. A. Zwaan; M. Dijkstra; F. H. Briggs; K. C. Freeman

2001-11-13

197

Two-Dimensional Space-Time Dependent Multi-group Diffusion Equation with SLOR Method  

NASA Astrophysics Data System (ADS)

The research of two-dimensional space-time diffusion equations with SLOR (Successive-Line Over Relaxation) has been done. SLOR method is chosen because this method is one of iterative methods that does not required to defined whole element matrix. The research is divided in two cases, homogeneous case and heterogeneous case. Homogeneous case has been inserted by step reactivity. Heterogeneous case has been inserted by step reactivity and ramp reactivity. In general, the results of simulations are agreement, even in some points there are differences.

Yulianti, Y.; Su'ud, Z.; Waris, A.; Khotimah, S. N.

2010-06-01

198

Between-group behaviour in health care: gaps, edges, boundaries, disconnections, weak ties, spaces and holes. A systematic review  

PubMed Central

Background Gaps are typically regarded as a problem to be solved. People are stimulated to close or plug them. Researchers are moved to fill deficits in the literature in order to realise a more complete knowledge base, health authorities want to bridge policy-practice disconnections, managers to secure resources to remedy shortfalls between poor and idealised care, and clinicians to provide services to patients across the divides of organisational silos. Despite practical and policy work in many health systems to bridge gaps, it is valuable to study research examining them for the insights provided. Structural holes, spaces between social clusters and weak or absent ties represent fissures in networks, located in less densely populated parts of otherwise closely connected social structures. Such gaps are useful as they illustrate how communication potentially breaks down or interactivity fails. This paper discusses empirical and theoretical work on this phenomenon with the aim of analysing a specific exemplar, the structures of silos within health care organisations. Methods The research literature on social spaces, holes, gaps, boundaries and edges was searched systematically, and separated into health [n = 13] and non-health [n = 55] samples. The health literature was reviewed and synthesised in order to understand the circumstances between stakeholders and stakeholder groups that both provide threats to networked interactions and opportunities to strengthen the fabric of organisational and institutional inter-relationships. Results The research examples illuminate various network structure characteristics and group interactions. They explicate a range of opportunities for improved social and professional relations that understanding structural holes, social spaces and absent ties affords. A principal finding is that these kinds of gaps illustrate the conditions under which connections are strained or have been severed, where the limits of integration between groups occurs, the circumstances in which social spaces are or need to be negotiated and the way divides are bridged. The study's limitations are that it is bounded by the focus of attention and the search terms used and there is yet to be developed a probabilistic, predictive model for gaps and how to connect them. Conclusions Gaps offer insights into social structures, and how real world behaviours of participants in workplaces, organisations and institutions are fragile. The paper highlights the circumstances in which network disjunctures and group divides manifest. Knowledge of these phenomenon provides opportunities for working out ways to improve health sector organisational communications, knowledge transmission and relationships. PMID:21134295

2010-01-01

199

The Origin of the ? Pictoris Moving Group  

NASA Astrophysics Data System (ADS)

The ? Pictoris moving group (BPMG) as proposed by Zuckerman et al. is a group of 19 low-mass star systems containing ? Pictoris and its protoplanetary disk. This nearest moving group is at a mean distance of 36 pc from the Earth, and these authors have proposed, by means of an H-R diagram, an evolutionary age of 12+8-4 Myr for this group. Here, by retracing the three-dimensional orbits of all the members of the BPMG and using a realistic Galactic potential, we find that a first maximum concentration of orbits occurs at 11.5 Myr and in a space region having a maximum size of 24 pc, 3 times smaller than its present size. We consider this region to be the birthplace of the BPMG. This interesting similarity of independently obtained evolutionary and kinematical ages indicates that this group could have already been formed as an unbound system, as observed today. The birthplace of the BPMG is located in a three-dimensional space, at ~45 pc from the region where the Lower Centaurus Crux (LCC) and Upper Centaurus Lupus (UCL) subgroups of the Scorpius-Centaurus OB association were when they were between 4 and 6 Myr old. At that age, both subgroups were able to produce supernovae (SNe) capable of triggering the formation of the BPMG. This interaction distance could even be smaller, up to ~26 pc, if SNe exploded in the outer regions of the LCC or UCL near the proposed birthplace of the BPMG. This scenario confirms, at least for the BPMG, the suggestion made by Mamajek & Feigelson and other authors that young unbound nearby stellar associations with ages around ~10 Myr originated in this OB complex. In contrast to the BPMG, for which we propose a coeval formation, the LCC and UCL subgroups appear not to be truly coeval.

Ortega, V. G.; de la Reza, R.; Jilinski, E.; Bazzanella, B.

2002-08-01

200

Anisotropies in the redshift-space correlations of galaxy groups and clusters - I. Simulated catalogues  

NASA Astrophysics Data System (ADS)

We analyse the correlation function of mock galaxy clusters in redshift space. We have constructed several mock catalogues designed to mimic the selection biases inherent in a variety of observational surveys. We explore different effects that contribute to the distortion of the clustering pattern: the pairwise velocity distribution of galaxy systems, coherent bulk motions, redshift errors and systematic effects in cluster identification. Our tests show that the redshift-space clustering pattern of galaxy systems is highly influenced by effects associated with the identification procedure from two-dimensional surveys. These systems show a spuriously large correlation amplitude, an effect that is present and even stronger in a subsample where the angular positions coincide with three-dimensional identified clusters. The effect of a small number of redshift measurements is also that of increasing the correlation amplitude. In a similar fashion, the bias parameter inferred from cluster samples is subject to these observational problems, which induce variations of up to a factor of 2 in such determinations. Also, we find that the estimated mean pairwise velocity dispersion can be up to an order of magnitude larger than the actual value. Errors in the estimated cluster redshift, originating from the use of too few redshift measurements per cluster, have a smaller impact on the measured correlation function. We show that an angular incompleteness in redshift surveys, such as that present in the 2dF Galaxy Redshift Survey 100 k public release, has no significant effect on the results. We suggest that the nature of projection effects arises mainly from structures along the line of sight in the filamentary large-scale clustering pattern. Thus, spectroscopic surveys are the only means of providing unbiased cluster samples. High-resolution plots and information are available at http://star-www.dur.ac.uk/~nelsonp/anisotropies.

Padilla, N. D.; Lambas, D. G.

2003-06-01

201

Space  

NSDL National Science Digital Library

This unit begins by introducing students to the historical motivation for space exploration. They learn about the International Space Station, including current and futuristic ideas that engineers are designing to propel space research. Then they learn about the physical properties of the Moon, and think about what types of products engineers would need to design in order for humans to live on the Moon. Lastly, students learn some descriptive facts about asteroids, such as their sizes and how that relates to the potential danger of an asteroid colliding with the Earth.

2014-09-18

202

Tablet PC Enhanced Curricula University of Washington  

E-print Network

Tablet PC Enhanced Curricula University of Washington Richard Anderson http://www.cs.washington.edu/education/dl/presenter/ 2. Students write answers on slides on their tablets and send them back to the instructor Classroom · Tablet PC based classroom interaction system · Supports inking on slides to integrate slide based content

Anderson, Richard

203

IPEG- IMPROVED PRICE ESTIMATION GUIDELINES (IBM PC VERSION)  

NASA Technical Reports Server (NTRS)

The Improved Price Estimation Guidelines, IPEG, program provides a simple yet accurate estimate of the price of a manufactured product. IPEG facilitates sensitivity studies of price estimates at considerably less expense than would be incurred by using the Standard Assembly-line Manufacturing Industry Simulation, SAMIS, program (COSMIC program NPO-16032). A difference of less than one percent between the IPEG and SAMIS price estimates has been observed with realistic test cases. However, the IPEG simplification of SAMIS allows the analyst with limited time and computing resources to perform a greater number of sensitivity studies than with SAMIS. Although IPEG was developed for the photovoltaics industry, it is readily adaptable to any standard assembly line type of manufacturing industry. IPEG estimates the annual production price per unit. The input data includes cost of equipment, space, labor, materials, supplies, and utilities. Production on an industry wide basis or a process wide basis can be simulated. Once the IPEG input file is prepared, the original price is estimated and sensitivity studies may be performed. The IPEG user selects a sensitivity variable and a set of values. IPEG will compute a price estimate and a variety of other cost parameters for every specified value of the sensitivity variable. IPEG is designed as an interactive system and prompts the user for all required information and offers a variety of output options. The IPEG/PC program is written in TURBO PASCAL for interactive execution on an IBM PC computer under DOS 2.0 or above with at least 64K of memory. The IBM PC color display and color graphics adapter are needed to use the plotting capabilities in IPEG/PC. IPEG/PC was developed in 1984. The original IPEG program is written in SIMSCRIPT II.5 for interactive execution and has been implemented on an IBM 370 series computer with a central memory requirement of approximately 300K of 8 bit bytes. The original IPEG was developed in 1980.

Aster, R. W.

1994-01-01

204

Building Neo-Riemannian Groups of Musical Transformations as Extensions  

E-print Network

Chords in musical harmony can be viewed as objects having shapes (major/minor/etc.) grafted on base spaces (pc-sets). The base space and the shape space are usually given the structure of a group, more particularly a cyclic group. In a more general setting, any object could be defined by its position on a base space and by its internal shape or state. The goal of this paper is to determine the structure of simply transitive groups of transformations acting on such sets of objects with internal symmetries. In the main proposition, we state that, under simple assumptions, these groups can be built as group extensions of the group associated to the base space by the group associated to the shape space, or the other way. By doing so, complex groups of transformations are obtained, including the traditional ones such as the dihedral groups. The knowledge of the group structure and product allows to explicitly build group actions on the objects. In particular we differentiate between left and right group actions an...

Popoff, Alexandre

2011-01-01

205

The Exploration Atmospheres Working Group's Report on Space Radiation Shielding Materials  

NASA Technical Reports Server (NTRS)

This part of Exploration Atmospheres Working Group analyses focuses on the potential use of nonmetallic composites as the interior walls and structural elements exposed to the atmosphere of the spacecraft or habitat. The primary drive to consider nonmetallic, polymer-based composites as an alternative to aluminum structure is due to their superior radiation shielding properties. But as is shown in this analysis, these composites can also be made to combine superior mechanical properties with superior shielding properties. In addition, these composites can be made safe; i.e., with regard to flammability and toxicity, as well as "smart"; i.e., embedded with sensors for the continuous monitoring of material health and conditions. The analysis main conclusions are that (1) smart polymer-based composites are an enabling technology for safe and reliable exploration missions, and (2) an adaptive, synergetic systems approach is required to meet the missions requirements from structure, properties, and processes to crew health and protection for exploration missions.

Barghouty, A. F.; Thibeault, S. A.

2006-01-01

206

Space-group symmetry fractionalization in a family of exactly solvable models with Z2 topological order  

NASA Astrophysics Data System (ADS)

We study square lattice space-group symmetry fractionalization in a family of exactly solvable models with Z2 topological order in two dimensions. In particular, we have obtained a complete understanding of which distinct types of symmetry fractionalization (symmetry classes) can be realized within this class of models, which are generalizations of Kitaev's Z2 toric code to arbitrary lattices. This question is motivated by earlier work of Essin and one of us (M. H.) [Phys. Rev. B 87, 104406 (2013), 10.1103/PhysRevB.87.104406], where the idea of symmetry classification was laid out, and which, for square lattice symmetry, produces 2080 symmetry classes consistent with the fusion rules of Z2 topological order. This approach does not produce a physical model for each symmetry class, and indeed there are reasons to believe that some symmetry classes may not be realizable in strictly two-dimensional systems, thus raising the question of which classes are in fact possible. While our understanding is limited to a restricted class of models, it is complete in the sense that for each of the 2080 possible symmetry classes, we either prove rigorously that the class cannot be realized in our family of models, or we give an explicit model realizing the class. We thus find that exactly 487 symmetry classes are realized in the family of models considered. With a more restrictive type of symmetry action, where space-group operations act trivially in the internal Hilbert space of each spin degree of freedom, we find that exactly 82 symmetry classes are realized. In addition, we present a single model that realizes all 26=64 types of symmetry fractionalization allowed for a single anyon species (Z2 charge excitation), as the parameters in the Hamiltonian are varied. The paper concludes with a summary and a discussion of two results pertaining to more general bosonic models.

Song, Hao; Hermele, Michael

2015-01-01

207

Inter-Agency Consultative Group for Space Science (IACG): Handbook of Missions and Payloads  

NASA Technical Reports Server (NTRS)

The ACE spacecraft design is based on the Charge Composition Explorer (CCE) built by Johns Hopkins University (JHU) and the Applied Physics Lab (APL) for the AMPTE program. ACE is designed as a spinning spacecraft with its spin axis aligned to the Earth-Sun axis. The ACE launch weight will be approx. 633 kg, including 105 kg of scientific instruments and 184 kg of propellant. Using a Delta-class expendable launch vehicle, ACE will be launched into an L1 libration point (240 R(sub e)) orbit. Telemetry will be 6.7 kbps average, using tape recorder storage with daily readout to DSN. The experiment power requirement is approximately 76 W nominal and 96 W peak. The prime objective of the ACE mission is: (1) to determine accurate elemental and isotropic abundances including solar matter, local interstellar matter and local galactic matter; (2) to study the origin of elements and evolutionary processing in galactic nucleosynthesis, galactic evolution, origin and evolution of the solar system; (3) to study coronal formation and solar-wind acceleration processes; and (4) to study particle acceleration and transport, including coronal shock acceleration, stochastic flare acceleration, interplanetary shock acceleration, and interstellar acceleration and propagation. To accomplish this objective, ACE will perform comprehensive and coordinated determinations of the elemental and isotopic composition of energetic nuclei accelerated on the Sun, in interplanetary space, and from galactic sources. These observations will span five decades in energy, from solar wind to galactic cosmic ray energies, and will cover the element range from H-1 to Zr-40. Comparison of these samples of matter will be used to study the origin and subsequent evolution of both solar system and galactic material by isolating the effects of fundamental processes that include nucleosynthesis, charged and neutral particle separation, bulk plasma acceleration, and the acceleration of suprathermal and high-energy particles.

1994-01-01

208

Behavioral and biological effects of autonomous versus scheduled mission management in simulated space-dwelling groups  

NASA Astrophysics Data System (ADS)

Logistical constraints during long-duration space expeditions will limit the ability of Earth-based mission control personnel to manage their astronaut crews and will thus increase the prevalence of autonomous operations. Despite this inevitability, little research exists regarding crew performance and psychosocial adaptation under such autonomous conditions. To this end, a newly-initiated study on crew management systems was conducted to assess crew performance effectiveness under rigid schedule-based management of crew activities by Mission Control versus more flexible, autonomous management of activities by the crews themselves. Nine volunteers formed three long-term crews and were extensively trained in a simulated planetary geological exploration task over the course of several months. Each crew then embarked on two separate 3-4 h missions in a counterbalanced sequence: Scheduled, in which the crews were directed by Mission Control according to a strict topographic and temporal region-searching sequence, and Autonomous, in which the well-trained crews received equivalent baseline support from Mission Control but were free to explore the planetary surface as they saw fit. Under the autonomous missions, performance in all three crews improved (more high-valued geologic samples were retrieved), subjective self-reports of negative emotional states decreased, unstructured debriefing logs contained fewer references to negative emotions and greater use of socially-referent language, and salivary cortisol output across the missions was attenuated. The present study provides evidence that crew autonomy may improve performance and help sustain if not enhance psychosocial adaptation and biobehavioral health. These controlled experimental data contribute to an emerging empirical database on crew autonomy which the international astronautics community may build upon for future research and ultimately draw upon when designing and managing missions.

Roma, Peter G.; Hursh, Steven R.; Hienz, Robert D.; Emurian, Henry H.; Gasior, Eric D.; Brinson, Zabecca S.; Brady, Joseph V.

2011-05-01

209

Incorporating Space Science Content Into the Undergraduate Curriculum by the NASA Education Forums' Higher Education Working Group  

NASA Astrophysics Data System (ADS)

As part of the NASA Education Forums, the Higher Education Working Group (HEWG) strives to support undergraduate science education through a variety of activities. These activities include: providing resource that incorporate space science topics into the existing undergraduate curriculum, understanding the role that community colleges play in STEM education and preparing STEM teachers, and identifying issues in diversity related to STEM education. To assess the best way of including space science into the undergraduate curriculum, the HEWG held a series of workshops and conducted surveys of undergraduate faculty who are conducting research in space science. During this engagement, the faculty expressed a need for a centralized repository of materials that can be used as part of already existing undergraduate courses in astronomy, physics, and earth science. Such a repository has since been developed, the 'EarthSpace Higher Education Clearing House (http://www.lpi.usra.edu/earthspace/) and it is still growing. Additional community tools, such as a newsletter, are provided through this website. To better understand the role and needs of community colleges, the HEWG undertook and extensive survey of community college STEM faculty. 187 faculty responded to the survey and the results show the extensive teaching load these faculty have, as well as the diverse demographics and the extent to which STEM teachers begin their preparation at 2 year institutions. Finally, the HEWG has begun to work on understanding the issues faced in increasing the diversity of the STEM work force. Progress and results of all this work will be summarized in this presentation.

Gross, N. A.; Buxner, S.; Cobabe-Ammann, E. A.; Fraknoi, A.; Moldwin, M.; Peticolas, L. M.; Low, R.; Schultz, G. R.

2013-12-01

210

PC Lube and Tune: PC and Internet Hardware and Software Tutorials  

NSDL National Science Digital Library

PC Lube and Tune, provided by Howard Gilbert, a Senior Research Programmer for Yale University's Computer and Information Systems, is a no-nonsense set of tutorials pertaining to PC computing. Internet tutorials of interest include "Distributed Applications and the Web," "Learning Java," "Introduction to TCP/IP," and "The Warp Internet Connection." There is also much useful information about the PC and networking world in general. There are tutorials on operating systems, considerations when changing operating systems, and PC hardware, among others. Many of the tutorials are illustrated. The power of this site is that even for those who don't get "under the hood" very often, it explains concepts in clear, concise language. And for those contemplating buying a PC, but for whom PC-features language might as well be Sumerian, the first tutorial, "An introduction to PC Hardware," is essential.

211

PC floor systems for microelectronics manufacturing buildings  

NASA Astrophysics Data System (ADS)

Because a PC(Precast Concrete) system has to follow the transportation rules for transporting PC units and be designed to the specifications of the tools and equipment on site, designing long-span PC systems for microelectronics manufacturing facilities can be troublesome due to complications in transporting, lifting and handling the PC units. To resolve these problems that can occur in long span and heavy weight PC designs, this study proposes two types of long-span PC floor systems that practically use the traditional Gerber beam concept. In the proposed systems, long-span (17.4m) girders or beams are segmented into appropriate lengths using the Gerber system for easy delivery and lifting. Moreover, these systems provide the ability to optimally design massive units by controlling the location of hinge points. On the other hand, because continuous long-span girders or beams are segmented into the Gerber system's hinge points, these systems may generate structural stability problems during construction. Consequently, this study experimentally examines the structural performance of stress transfer mechanism in panel zones and the construction stability of PC units for columns and girders during assembly.

Hong, Kappyo; Lee, Seongsoo; Kwon, Yunhan; Chun, Homin; Cho, Kwangsu; Kim, Sijun

2009-12-01

212

PC floor systems for microelectronics manufacturing buildings  

NASA Astrophysics Data System (ADS)

Because a PC(Precast Concrete) system has to follow the transportation rules for transporting PC units and be designed to the specifications of the tools and equipment on site, designing long-span PC systems for microelectronics manufacturing facilities can be troublesome due to complications in transporting, lifting and handling the PC units. To resolve these problems that can occur in long span and heavy weight PC designs, this study proposes two types of long-span PC floor systems that practically use the traditional Gerber beam concept. In the proposed systems, long-span (17.4m) girders or beams are segmented into appropriate lengths using the Gerber system for easy delivery and lifting. Moreover, these systems provide the ability to optimally design massive units by controlling the location of hinge points. On the other hand, because continuous long-span girders or beams are segmented into the Gerber system's hinge points, these systems may generate structural stability problems during construction. Consequently, this study experimentally examines the structural performance of stress transfer mechanism in panel zones and the construction stability of PC units for columns and girders during assembly.

Hong, Kappyo; Lee, Seongsoo; Kwon, Yunhan; Chun, Homin; Cho, Kwangsu; Kim, Sijun

2010-03-01

213

Induction of cytoprotective autophagy in PC-12 cells by cadmium  

SciTech Connect

Highlights: •Cadmium can promote early upregulation of autophagy in PC-12 cells. •Autophagy precedes apoptosis in cadmium-treated PC-12 cells. •Cadmium-induced autophagy is cytoprotective in PC-12 cells. •Class III PI3K/beclin-1/Bcl-2 signaling pathway plays a positive role in cadmium-triggered autophagy. -- Abstract: Laboratory data have demonstrated that cadmium (Cd) may induce neuronal apoptosis. However, little is known about the role of autophagy in neurons. In this study, cell viability decreased in a dose- and time-dependent manner after treatment with Cd in PC-12 cells. As cells were exposed to Cd, the levels of LC3-II proteins became elevated, specific punctate distribution of endogenous LC3-II increased, and numerous autophagosomes appeared, which suggest that Cd induced a high level of autophagy. In the late stages of autophagy, an increase in the apoptosis ratio was observed. Likewise, pre-treatment with chloroquine (an autophagic inhibitor) and rapamycin (an autophagic inducer) resulted in an increased and decreased percentage of apoptosis in contrast to other Cd-treated groups, respectively. The results indicate that autophagy delayed apoptosis in Cd-treated PC-12 cells. Furthermore, co-treatment of cells with chloroquine reduced autophagy and cell activity. However, rapamycin had an opposite effect on autophagy and cell activity. Moreover, class III PI3 K/beclin-1/Bcl-2 signaling pathways served a function in Cd-induced autophagy. The findings suggest that Cd can induce cytoprotective autophagy by activating class III PI3 K/beclin-1/Bcl-2 signaling pathways. In sum, this study strongly suggests that autophagy may serve a positive function in the reduction of Cd-induced cytotoxicity.

Wang, Qiwen [College of Veterinary Medicine, Yangzhou University, Yangzhou 225009 (China) [College of Veterinary Medicine, Yangzhou University, Yangzhou 225009 (China); Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009 (China); Bijie Pilot Area Research Institute of Bijie University, Bijie 551700 (China); Zhu, Jiaqiao; Zhang, Kangbao; Jiang, Chenyang; Wang, Yi; Yuan, Yan; Bian, Jianchun; Liu, Xuezhong; Gu, Jianhong [College of Veterinary Medicine, Yangzhou University, Yangzhou 225009 (China) [College of Veterinary Medicine, Yangzhou University, Yangzhou 225009 (China); Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009 (China); Liu, Zongping, E-mail: liuzongping@yzu.edu.cn [College of Veterinary Medicine, Yangzhou University, Yangzhou 225009 (China) [College of Veterinary Medicine, Yangzhou University, Yangzhou 225009 (China); Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009 (China)

2013-08-16

214

Scale-PC shielding analysis sequences  

SciTech Connect

The SCALE computational system is a modular code system for analyses of nuclear fuel facility and package designs. With the release of SCALE-PC Version 4.3, the radiation shielding analysis community now has the capability to execute the SCALE shielding analysis sequences contained in the control modules SAS1, SAS2, SAS3, and SAS4 on a MS- DOS personal computer (PC). In addition, SCALE-PC includes two new sequences, QADS and ORIGEN-ARP. The capabilities of each sequence are presented, along with example applications.

Bowman, S.M.

1996-05-01

215

Dispersive Pc1 bursts observed by Freja  

SciTech Connect

The authors report on observation of electromagnetic ion cyclotron waves (Pc1 pulsations) by the Freja satellite on November 18, 1992. These observations are coincident with ground based observation of such pearl like Pc1 pulsations extending over a 12 hour period. This is the first observation by a satellite above the ionosphere of such phenomena. The wave pulsations were observed to come in 10 to 25 second pulses, and to be clearly dispersive in nature. Two spectral bands were observed in all Pc1 pearls. In the longer bursts, the authors observed time differences between the two distinct spectral bands.

Mursula, K.; Braeysy, T.; Rasinkangas, R.; Tanskanen, P. [Univ. of Oulu (Finland)] [Univ. of Oulu (Finland); Blomberg, L.G.; Lindqvist, P.A.; Marklund, G.T. [Royal Institute of Technology, Stockholm (Sweden)] [Royal Institute of Technology, Stockholm (Sweden)

1994-08-15

216

Calculating field emission current in nanodiodes—A multi-group formalism with space charge and exchange-correlation effects  

SciTech Connect

Inclusion of electron-electron interaction is essential in nano-diodes to understand the underlying physical phenomenon and tailor devices accordingly. However, both space charge and exchange-correlation interaction involve electrons at different energies and hence a self-consistent multi-energy-group solution of the Schrödinger-Poisson system is required. It is shown here that the existence of a limiting density-dependent potential at low applied voltages allows calculation of the field emission current. Despite additional interactions, a Fowler-Nordheim behaviour is observed. It is also found that the exchange-correlation potential dominates at these voltages in nanogaps and possibly leads to a higher turn-on voltage.

Biswas, Debabrata; Kumar, Raghwendra [Theoretical Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2014-03-21

217

Coordination of Advanced Solar Observatory (ASO) Science Working Group (SWG) for the study of instrument accommodation and operational requirements on space station  

NASA Technical Reports Server (NTRS)

The objectives are to coordinate the activities of the Science Working Group (SWG) of the Advanced Solar Observatory (ASO) for the study of instruments accommodation and operation requirements on board space station. In order to facilitate the progress of the objective, two conferences were organized, together with two small group discussions.

Wu, S. T.

1989-01-01

218

Anisotropies in the redshift-space correlations of galaxy groups and clusters II: Analysis of observational cluster samples  

E-print Network

We study the redshift space correlation function of galaxy clusters for observational samples constructed in different surveys. We explore correlation amplitudes, pairwise velocity distributions and bias factors. Systematics in cluster identification procedures are the main source of biased estimates of the correlation amplitude and inferred velocity dispersions. By comparing our results with those of numerical simulations we explore the strong influence on the clustering distortion pattern in redshift space from effects associated with the cluster identification procedure from two dimensional surveys as is the case of Abell and APM clusters. The identification of clusters in X-ray surveys improves this situation, although there are still systematic effects which are probably due to identification of optical sources in the determination of cluster redshifts. These systematics are particularly strong for the most luminous X-ray selected clusters in the Extended Bright Cluster Survey, which exhibits very large anisotropies, comparable to those present in the Abell catalogue. Our results demonstrate that forthcoming large redshift surveys will be extremely important for the construction of new samples of groups and clusters as well as improving the determination of optical and X-ray selected cluster distances, essential for reliable analyses of the large scale structure.

N. D. Padilla; D. G. Lambas

2003-02-16

219

E-Books and the Tablet PC.  

ERIC Educational Resources Information Center

Highlights the emerging technologies of e-books, electronic versions of texts, and the Tablet PC, a new hybrid laptop computer and personal digital assistant that features a writing tablet and stylus-based input/navigation. (Author/VWL)

Goodwin-Jones, Bob

2003-01-01

220

Three Kazal-type serine proteinase inhibitors from the red swamp crayfish Procambarus clarkii and the characterization, function analysis of hcPcSPI2.  

PubMed

Three Kazal-type serine proteinase inhibitors, hcPcSPI2, hpPcSPI3, and hpPcSPI4, with complete cDNA sequences, were identified from a cDNA library of the red swamp crayfish, Procambarus clarkii. Semi-quantitative RT-PCR shows that hcPcSPI2 exists mainly in hemocytes while both hpPcSPI3 and hpPcSPI4 were detected in the hepatopancreas and the heart. Homology comparison and phylogenic analysis indicate that hpPcSPI3 and hpPcSPI4 shared high identity and formed the same group, and both of them were different from other hepatopancreas type inhibitors in crustaceans forming a large group, while hcPcSPI2 as well as other hemocyte type inhibitors belonged to another cluster. In addition, the temporal expression profiles of these three inhibitors were studied with quantitative real-time PCR and the results suggest that hcPcSPI2 and hpPcSPI3 are likely to be involved in antiviral immune response, and all these three inhibitors respond to Vibrio anguillarum challenge in different degrees. Further study was done on hcPcSPI2. Western blot demonstrates that hcPcSPI2 only exists in semigranular cells. Besides, after V. anguillarum challenge, the hcPcSPI2 protein could also be detected in cell-free hemolymph. Subsequently, the biochemical characteristics and bacteriostatic activity of hcPcSPI2 were assayed. The results indicate that hcPcSPI2 shows weak inhibitory activity against subtilisin A and trypsin, and may trigger bacteriostatic activity towards Bacillus subtilis and Bacillus thuringiensis, possessing MIC(50) of 30.4 and 25.0 microM, respectively. These studies reveal that hcPcSPI2 may also play an important role in the anti-bacterial immunity of the crayfish. PMID:20170735

Li, Xin-Cang; Zhang, Ran-Ran; Sun, Rong-Rong; Lan, Jiang-Feng; Zhao, Xiao-Fan; Wang, Jin-Xing

2010-01-01

221

Practical Pocket PC Application w/Biometric Security  

NASA Technical Reports Server (NTRS)

I work in the Flight Software Engineering Branch, where we provide design and development of embedded real-time software applications for flight and supporting ground systems to support the NASA Aeronautics and Space Programs. In addition, this branch evaluates, develops and implements new technologies for embedded real-time systems, and maintains a laboratory for applications of embedded technology. The majority of microchips that are used in modern society have been programmed using embedded technology. These small chips can be found in microwaves, calculators, home security systems, cell phones and more. My assignment this summer entails working with an iPAQ HP 5500 Pocket PC. This top-of-the-line hand-held device is one of the first mobile PC's to introduce biometric security capabilities. Biometric security, in this case a fingerprint authentication system, is on the edge of technology as far as securing information. The benefits of fingerprint authentication are enormous. The most significant of them are that it is extremely difficult to reproduce someone else's fingerprint, and it is equally difficult to lose or forget your own fingerprint as opposed to a password or pin number. One of my goals for this summer is to integrate this technology with another Pocket PC application. The second task for the summer is to develop a simple application that provides an Astronaut EVA (Extravehicular Activity) Log Book capability. The Astronaut EVA Log Book is what an astronaut would use to report the status of field missions, crew physical health, successes, future plans, etc. My goal is to develop a user interface into which these data fields can be entered and stored. The applications that I am developing are created using eMbedded Visual C++ 4.0 with the Pocket PC 2003 Software Development Kit provided by Microsoft.

Logan, Julian

2004-01-01

222

Evidence that PC2 is the endogenous pro-neurotensin convertase in rMTC 6-23 cells and that PC1- and PC2-transfected PC12 cells differentially process pro-neurotensin.  

PubMed

The neuropeptide precursor proneurotensin/neuromedin N (pro-NT/NN) is mainly expressed and differentially processed in the brain and in the small intestine. We showed previously that rMTC 6-23 cells process pro-NT/NN with a pattern similar to brain tissue and increase pro-NT/NN expression in response to dexamethasone, and that PC12 cells also produce pro-NT/NN but are virtually unable to process it. In addition, PC12 cells were reported to be devoid of the prohormone convertases PC1 and PC2. The present study was designed to identify the proprotein convertase(s) (PC) involved in pro-NT/NN processing in rMTC 6-23 cells and to compare PC1- and PC2-transfected PC12 cells for their ability to process pro-NT/NN. rMTC 6-23 cells were devoid of PC1, PC4, and PC5 but expressed furin and PC2. Stable expression of antisense PC2 RNA in rMTC 6-23 cells led to a 90% decrease in PC2 protein levels that correlated with a > 80% reduction of pro-NT/NN processing. PC2 expression was stimulated by dexamethasone in a time- and concentration-dependent manner. Stable PC12/PC2 transfectants processed pro-NT/NN with a pattern similar to that observed in the brain and in rMTC 6-23 cells. In contrast, stable PC12/PC1 transfectants reproduced the pro-NT/NN processing pattern seen in the gut. We conclude that (i) PC2 is the major pro-NT/NN convertase in rMTC 6-23 cells; (ii) its expression is coregulated with that of pro-NT/NN in this cell line; and (iii) PC2 and PC1 differentially process pro-NT/NN with brain and intestinal phenotype, respectively. PMID:8626691

Rovère, C; Barbero, P; Kitabgi, P

1996-05-10

223

Tablet PC and Computing Curriculum Initiative Evaluation of Tablet PC Supported Pedagogy  

E-print Network

Tablet PC and Computing Curriculum Initiative 2006 Evaluation of Tablet PC Supported Pedagogy http://www.cs.washington.edu/education/dl/presenter/ University of Washington Richard Anderson 2. Students write answers on slides on their tablets and send them to show on public display for discussion Classroom Interaction with Tablet PCs Classroom Presenter Tablet

Anderson, Richard

224

Previously the domain of PC games PC networked games are very popular  

E-print Network

Networking 1 #12;· Previously the domain of PC games ­ PC networked games are very popular generation ­ Halo, CoD are huge ­ All Xbox360 games must have an online feature Networking Present and Future #12;Challenges · Has a huge impact on a game architecture ­ Complicates many aspects of the design

Stephenson, Ben

225

Emissions tracking system (ETS-PC) software  

SciTech Connect

The U.S. EPA Acid Rain Division developed and is maintaining the Emissions Tracking System (ETS) to receive, store and analyze data from continuous emissions monitors (CEMs) submitted by utilities affected by the 1990 Clean Air Act. This paper will describe ETS-PC, a PC application developed by EPA to assist utilities in analyzing and submitting emission data files each quarter. ETS-PC includes quality assurance software which helps utilities identify possible errors in their quarterly data files (QDFs) prior to submission. It also includes communications software which allows utilities to transfer QDFs via modem directly to the EPA mainframe computer located in Research Triangle Park, NC. After a file is transferred, users are provided with immediate feedback from the mainframe in the form of a file transfer receipt and summary.

Weatherbee, J. Jr.; Kress, T. [Science Applications International Corp., McLean, VA (United States)

1997-12-31

226

"I am a waste of breath, of space, of time": metaphors of self in a pro-anorexia group.  

PubMed

According to recent research on eating disorders, heavy users of pro-anorexia (pro-ana) sites show higher levels of disordered eating and more severe impairment of quality of life than non-heavy users. A better understanding of how pro-ana members self-present in the virtual world could shed some light on these offline behaviors. Through discourse analysis, I examined the metaphors the members of a pro-ana group invoked in their personal profiles on a popular social networking site, to talk about the self. I applied the Metaphor Identification Procedure to 757 text profiles. I identified four key metaphorical constructions in pro-ana members' self-descriptions: self as space, self as weight, perfecting the self, and the social self. These four main metaphors represented discourse strategies, both to create a collective pro-ana identity and to enact an individual identity as pro-ana. In this article, I discuss the implications of these findings for the treatment of eating disorders. PMID:25225049

Bates, Carolina Figueras

2015-02-01

227

LETTER TO THE EDITOR: Space-group symmetry for the perovskite Ca0.3Sr0.7TiO3  

NASA Astrophysics Data System (ADS)

It is shown, using synchrotron x-ray powder diffraction at room temperature and above, by invoking geometrical and symmetry arguments, and most directly by electron diffraction, that the perovskite Ca0.3Sr0.7TiO3 at room temperature is tetragonal with space-group symmetry I4/mcm. This is in accord with the common view (Ball et al 1998 J. Solid State Chem. 139 238-47). The proposition that the compound adopts a metrically tetragonal orthorhombic structure in space group Imma (Ranjan and Pandey 1999 J. Phys.: Condens. Matter 11 2247-58) cannot be sustained.

Howard, C. J.; Withers, R. L.; Zhang, Z.; Osaka, K.; Kato, K.; Takata, M.

2005-11-01

228

PC-ATOMIC Final Report 1 Joseph D. Touch1  

E-print Network

PC-ATOMIC Final Report 1 PC-ATOMIC Joseph D. Touch1 USC / Information Sciences Institute touch of the board are available as government-furnished equipment for research pur- poses. FIGURE 1. PC-ATOMIC board to PC-ATOMIC. 1. This research was sponsored by the Advanced Research Projects Agency through Ft

Touch, Joe

229

IPv6 PC IPv6 2001-003  

E-print Network

IPv6 PC 1 IPv6 2001-003 1. FreeBSD 2. 3. IPv6 4. 5. IPv6 6. PC 7. IPv6 APPENDIX: rc.conf (PC-Router ) IPv6 PC (FreeBSD 4.2) IPv6 PC Router & Host Configuration (for FreeBSD 4.2) (J. H. Jeong ) ETRI (S. Y. Lee) ETRI (Y.J. Kim) ETRI #12;IPv6 2001-003 2

Jeong, Jaehoon "Paul"

230

Proinsulin processing by the subtilisin-related proprotein convertases furin, PC2, and PC3.  

PubMed Central

Experiments using recombinant vaccinia viruses expressing rat proinsulin I coinfected into COS-7 cells with recombinant vaccinia virus expressing human furin, human PC2, mouse PC3 (subtilisin-related proprotein convertases 1-3, respectively), or yeast Kex2 indicate that in this system both Kex2 and furin produce mature insulin, whereas PC2 selectively cleaves proinsulin at the C-peptide-A-chain junction. This is a property consistent with its probable identity with the rat insulinoma granule type II proinsulin processing activity as described by Davidson et al. [Davidson, H. W., Rhodes, C. J. & Hutton, J. C. (1988) Nature (London) 333, 93-96]. PC3 generates mature insulin but cleaves preferentially at the proinsulin B-chain-C-peptide junction. This pattern of cleavage by PC3 is similar, but not identical, to that of the highly B-chain-C-peptide junction-selective type I activity as described by Davidson et al., perhaps due to the presence of a P4 arginine residue near the C-peptide-A-chain junction unique to the rat proinsulins. These results along with data presented on the expression of both PC2 and PC3 in islet beta cells strongly support the conclusion that these proteases are involved in the conversion of proinsulin to insulin in vivo. Images PMID:1528899

Smeekens, S P; Montag, A G; Thomas, G; Albiges-Rizo, C; Carroll, R; Benig, M; Phillips, L A; Martin, S; Ohagi, S; Gardner, P

1992-01-01

231

Deproletarianizing Agriculture Lemmens, P.C.  

E-print Network

Deproletarianizing Agriculture Lemmens, P.C. ISDA 2010, Montpellier, June 28-30, 2010 1 DEPROLETARIANIZING AGRICULTURE RECOVERING AGRICULTURE FROM AGRIBUSINESS AND THE NEED FOR A COMMONS-BASED, OPEN SOURCE AGRICULTURE Dr. Pieter LEMMENS Wageningen University Centre for Methodical Ethics and Technology Assessment

Boyer, Edmond

232

Mathematics Instruction and the Tablet PC  

ERIC Educational Resources Information Center

The use of tablet PCs in teaching is a relatively new phenomenon. A cross between a notebook computer and a personal digital assistant (PDA), the tablet PC has all of the features of a notebook with the additional capability that the screen can also be used for input. Tablet PCs are usually equipped with a stylus that allows the user to write on…

Fister, K. Renee; McCarthy, Maeve L.

2008-01-01

233

PC Games and the Teaching of History  

ERIC Educational Resources Information Center

Although the use of PC games in the history classroom might be relatively new, the ideas for these assignments and the theory behind their use borrows heavily from a number of areas and combines different pedagogical techniques. Using computer games allows teachers to recombine disparate teaching threads into something novel that will serve…

McMichael, Andrew

2007-01-01

234

Inside This IST evaluates PC games'  

E-print Network

good video games, adding low- cost components that help replicate the flight experience and analyzingReview Vol. 11 #2 April 1999 Inside This Issue Page 2: IST evaluates PC games' potential for real-April with the intention of filling the position by fall. Mr. Goldiez expects to continue IST's leading role in simulation

Stanley, Kenneth O.

235

Jargon that Computes: Today's PC Terminology.  

ERIC Educational Resources Information Center

Discusses PC (personal computer) and telecommunications terminology in context: Integrated Services Digital Network (ISDN); Asymmetric Digital Subscriber Line (ADSL); cable modems; satellite downloads; T1 and T3 lines; magnitudes ("giga-,""nano-"); Central Processing Unit (CPU); Random Access Memory (RAM); Universal Serial Bus (USB); "Firewire,"…

Crawford, Walt

1997-01-01

236

Group dynamics in a long-term blind endeavor on Earth: An analog for space missions (Lewis & Clark Expedition group dynamic analysis)  

Microsoft Academic Search

In 1803, President Thomas Jefferson set fourth a military expedition led by Captains M. Lewis and W. Clark (Lewis and Clark Expedition) on an exploration that would become an everlasting part of US national history and pride. Looking back at the events of this exploration, there are many similarities to the experiences future human space explorers will face as we

M. Allner; V. Rygalov

2008-01-01

237

CASE STUDY -- LEAN 94-02: A Case Study of Self-Directed Work Teams at Boeing Defense and Space Group - Corinth  

E-print Network

Boeing Defense & Space Group - Corinth (BD&SG-C) is a self-directed team based unionized facility in the defense and commercial aircraft industry. The plant was a greenfield start-up in 1987. Due to the nature of the defense ...

Klein, Janice

1994-02-24

238

D-Side: A Facility and Workforce Planning Group Multi-criteria Decision Support System for Johnson Space Center  

NASA Technical Reports Server (NTRS)

"To understand and protect our home planet, to explore the universe and search for life, and to inspire the next generation of explorers" is NASA's mission. The Systems Management Office at Johnson Space Center (JSC) is searching for methods to effectively manage the Center's resources to meet NASA's mission. D-Side is a group multi-criteria decision support system (GMDSS) developed to support facility decisions at JSC. D-Side uses a series of sequential and structured processes to plot facilities in a three-dimensional (3-D) graph on the basis of each facility alignment with NASA's mission and goals, the extent to which other facilities are dependent on the facility, and the dollar value of capital investments that have been postponed at the facility relative to the facility replacement value. A similarity factor rank orders facilities based on their Euclidean distance from Ideal and Nadir points. These similarity factors are then used to allocate capital improvement resources across facilities. We also present a parallel model that can be used to support decisions concerning allocation of human resources investments across workforce units. Finally, we present results from a pilot study where 12 experienced facility managers from NASA used D-Side and the organization's current approach to rank order and allocate funds for capital improvement across 20 facilities. Users evaluated D-Side favorably in terms of ease of use, the quality of the decision-making process, decision quality, and overall value-added. Their evaluations of D-Side were significantly more favorable than their evaluations of the current approach. Keywords: NASA, Multi-Criteria Decision Making, Decision Support System, AHP, Euclidean Distance, 3-D Modeling, Facility Planning, Workforce Planning.

Tavana, Madjid

2005-01-01

239

pc1 and psc1, zebrafish homologs of Drosophila Polycomb and Posterior sex combs, encode nuclear proteins capable of complex interactions  

Microsoft Academic Search

Drosophila Polycomb group proteins are thought to form multimeric nuclear complexes that are responsible for stable transmission of repressed states of gene expression during the proliferation of differentiating embryos. In this study, we cloned, sequenced, and characterized two Polycomb group homologs, designated pc1 and psc1, in zebrafish. Amino acid sequence analyses determined that pc1 is a structural homolog of Drosophila

Akinori Kawamura; Shin'ichiro Yokota; Kouji Yamada; Hitoshi Inoue; Keiji Inohaya; Ken Yamazaki; Ikuo Yasumasu; Toru Higashinakagawa

2002-01-01

240

A prototype PC-based system of giving color estimation ability to monochrome security cameras  

Microsoft Academic Search

A prototype PC-based system of giving color estimation ability to monochrome security cameras has been developed based on the novel concept. The novel concept can be divided into 3 stages. First, space-variant color filter is put onto the lens of the monochrome security camera. Secondly, when a crime takes place, the camera records suspected person. Finally, just after the crime,

Yoichi Sugita; Yusaku Fujii; Naoya Ohta; Hiroshi Ueda; Masayuki Yokota; Ryosuke Sakurai

2007-01-01

241

Immunologic memory to phosphorylcholine. II. PC-KLH induces two antibody populations that dominate different isotypes.  

PubMed

We examined the fine specificity of the memory response to phosphorylcholine (PC) using an enzyme-linked immunosorbent assay (ELISA) that measures the relative abilities of PC analogs to inhibit the binding of antibody to antigen. Along with the usual haptens (phosphorylcholine, L-alpha-glycerophosphorylcholine, and choline) these studies included as an inhibitor p-nitrophenyl phosphorylcholine, a compound that is homologous to the structure of the PC antigen in a protein conjugate. Evaluation of the fine specificity profiles revealed two populations of antibody elicited by PC-KLH, which were unequally dominant among the various immunoglobulin classes and IgG subclasses. Group I antibodies exhibited a similar or slightly greater avidity for PC than for NPPC and constituted the majority of IgM, IgA, and IgG3 antibodies. Group II antibodies, which were expressed primarily by IgG1, IgG2a, and IgG2b antibodies, possessed significant avidity only for NPPC. Possible mechanisms that would link IgM, IgA, and IgG3 to similar variable regions while excluding IgG1, IgG2a, and IgG2b from the same grouping are discussed. PMID:7054294

Chang, S P; Brown, M; Rittenberg, M B

1982-02-01

242

Regulation of PrPC signaling and processing by dimerization  

PubMed Central

The cellular prion protein (PrPC) is a glycosylphosphatidylinositol (GPI)-anchored protein present at the cell surface. PrPC N-terminal moiety is intrinsically disordered and is able to interact with a variety of ligands. Physiological ligands have neurotrophic activity, whilst others, including protein toxic oligomers, have neurotoxic functions. These two opposite activities involve different interacting partners and result from different PrPC-activated signaling pathways. Remarkably, PrPC may be inactivated either by physiological endoproteolysis and release of the N-terminal domain, or by ectodomain shedding. Ligand-induced PrPC dimerization or enforced dimerization of PrPC indicate that PrPC dimerization represents an important molecular switch for both intracellular signaling and inactivation by the release of PrPC N-terminal domain or shedding. In this review, we summarize evidence that cell surface receptor activity of PrPC is finely regulated by dimerization. PMID:25364762

Roucou, Xavier

2014-01-01

243

Synchronization of heart rate indices of human and Pc5 pulsations in the geomagnetic quiet conditions  

NASA Astrophysics Data System (ADS)

Geomagnetic pulsations with duration of the period over 150 seconds (Pc5-6) are present in the magnetosphere almost constantly. Unlike other types of geomagnetic pulsations, they are characterized by high amplitudes reaching in auroral latitudes 30-100 nT, and even 300 - 600 nT in time of significant geomagnetic disturbances [1]. To date, it is generally accepted that the classic morning and afternoon Pc5 pulsations in the magnetosphere are toroidal Alfven resonance vibrations of the geomagnetic field lines [2, 3]. It was revealed that the basic oscillation periods, presented in heart rate variability of healthy subjects, in conditions of rest, at each time point substantially coincide with the periods of oscillation of the X-vector components of the geomagnetic field in the frequency range of Pc5-6 pulsations. Synchronization effect was observed in approximately 60% of cases [4]. The above statement is based on the results of more than 100 experiments (recording time from 60 to 200 min), conducted in the period 2011-2013 in various research groups [4]. In total, 37 volunteers in the age range 18-65 yrs took part in the experiments. Experiments were performed in Pushchino and Khimki (Moscow region), Arkhangelsk, Tomsk, Sofia (Bulgaria), as well as at the station Starorusskaya (Leningrad region). The geomagnetic data were obtained from INTERMAGNET network (http://ottawa.intermagnet.org/Welcom_e.php). From a biophysical point of view, the observed effects of timing fluctuations of heart rate of healthy subjects with the oscillations of the magnetic induction vector of the GMF could be an effective tool for solving one of the most actual problems in heliobiophysics, namely the identification of specific physiological mechanisms of biosystems response to low-intensity variations external factors. 1. Pilipenko V.A., Kleimenova N.G., Kozyreva O.V., Yumoto K., Bitterly G. Geomagnetism and aeronomy, 1997, V. 37, ?.3, P. 64-76 2. Chen L. and Hasegawa A. J.Geophys. Res. 1974. Vol.79,P.1024-1032 3. Southwood D.J. Planet. Space Sci. 1974. Vol.22, P.483-491. 4.Zenchenko T.A., Medvedeva A.A., Khorseva N.I., Breus T.K. // Geophysical Processes and Biosphere. 2013. V. 12. ? 4. P. 73-84

Zenchenko, Tatiana

244

PC-SEAPAK user's guide, version 4.0  

NASA Technical Reports Server (NTRS)

PC-SEAPAK is designed to provide a complete and affordable capability for processing and analysis of NOAA Advanced Very High Resolution Radiometer (AVHRR) and Nimbus-7 Coastal Zone Color Scanner (CZCS) data. Since the release of version 3.0 over a year ago, significant revisions were made to the AVHRR and CZCS programs and to the statistical data analysis module, and a number of new programs were added. This new version has 114 procedures listed in its menus. The package continues to emphasize user-friendliness and interactive data analysis. Additionally, because the scientific goals of the ocean color research being conducted have shifted to larger space and time scales, batch processing capabilities were enhanced, allowing large quantities of data to be easily ingested and analyzed. The development of PC-SEAPAK was paralled by two other activities that were influential and assistive: the global CZCS processing effort at GSFC and the continued development of VAX-SEAPAK. SEAPAK incorporates the instrument calibration and support all levels of data available from the CZCS archive.

Mcclain, Charles R.; Fu, Gary; Darzi, Michael; Firestone, James K.

1992-01-01

245

The moduli space and monodromies of the N=2 supersymmetric Yang-Mills theory with any Lie gauge groups  

E-print Network

We propose a unified scheme for finding the hyperelliptic curve of N=2 SUSY YM theory with any Lie gauge groups. Our general scheme gives the well known results for classical gauge groups and exceptional G_2 group. In particular, we present the curve for the exceptional gauge groups F_4, E_{6,7,8} and check consistency condition for them. The exact monodromies and the dyon spectrum of these theories are determined. We note that for any Lie gauge groups, the exact monodromies could be obtained only from the Cartan matrix.

Abolhasani, M R; Ghezelbash, A M; Abolhasani, Mohammad Reza; Alishahiha, Mohsen; Ghezelbash, Amir Masoud

1996-01-01

246

Linear programming systems mainframe to PC  

SciTech Connect

As the PC technology enters the control/integration stage of Nolan's Stage Hypothesis for MIS systems, the software for LP's are shifting from vertical to horizontal markets. This shift will allow large organizations to discard ''baggage'' that has hindered the acquisition of new technology because of upward compatibility problems yet not discard previous sunk cost of development. Also, this horizontal software alleviates personnel problems of professional having to learn both the IBM/370 type operating systems and the PC operating systems. This horizontal market software will allow both large and small companies to efficiently push optimization techniques to different parts of the organization since different applications can be developed from a single software package. This ultimately leads to improved decision-making at different levels of the company which, in the long run, will lead to increased revenues.

Luce, G.W.

1987-01-01

247

IBM PC enhances the world's future  

NASA Technical Reports Server (NTRS)

Although the purpose of this research is to illustrate the importance of computers to the public, particularly the IBM PC, present examinations will include computers developed before the IBM PC was brought into use. IBM, as well as other computing facilities, began serving the public years ago, and is continuing to find ways to enhance the existence of man. With new developments in supercomputers like the Cray-2, and the recent advances in artificial intelligence programming, the human race is gaining knowledge at a rapid pace. All have benefited from the development of computers in the world; not only have they brought new assets to life, but have made life more and more of a challenge everyday.

Cox, Jozelle

1988-01-01

248

PC Wizard 2009 1.90  

NSDL National Science Digital Library

With so many free options for system utilities, it can be hard to separate the wheat from the chaff. PC Wizard 2009 1.90 is a most worthy option, and visitors can use the program to not only detect hardware performance, but it will also look at hard disk performance, and display a graph to note how various elements in a given category perform. This version is compatible with computers running Windows 95 and newer.

249

ZDNet Special Report: PC Expo 2000  

NSDL National Science Digital Library

PC Expo 2000 is over, but readers can still get the lowdown on the gadgets and gizmos unveiled at the Jacob Javits Center in 2000. ZDNet's special coverage includes breaking and archived news, product previews and first impressions, commentary, and press releases. CNET offers pieces on new products, top trends of the coming year, and Best of Show awards. At the official site, users will find a list of exhibitors and speakers, and information on keynote programs.

2000-01-01

250

Immunological mimicry of PrPC interactions  

E-print Network

Immunological mimicry of PrPC ­PrPSc interactions: antibody-induced PrP misfolding Li Li1-Tyr-Arg (YYR) specifically recognize PrPSc and other misfolded PrP species. Here, we report that select bead-bound PrP-BCD mAbs induce exposure of bityrosine epitopes on mouse brain PrP. By competition

Plotkin, Steven S.

251

Virtual Reality at the PC Level  

NASA Technical Reports Server (NTRS)

The main objective of my research has been to incorporate virtual reality at the desktop level; i.e., create virtual reality software that can be run fairly inexpensively on standard PC's. The standard language used for virtual reality on PC's is VRML (Virtual Reality Modeling Language). It is a new language so it is still undergoing a lot of changes. VRML 1.0 came out only a couple years ago and VRML 2.0 came out around last September. VRML is an interpreted language that is run by a web browser plug-in. It is fairly flexible in terms of allowing you to create different shapes and animations. Before this summer, I knew very little about virtual reality and I did not know VRML at all. I learned the VRML language by reading two books and experimenting on a PC. The following topics are presented: CAD to VRML, VRML 1.0 to VRML 2.0, VRML authoring tools, VRML browsers, finding virtual reality applications, the AXAF project, the VRML generator program, web communities and future plans.

Dean, John

1998-01-01

252

CRYSTALLOGRAPHIC POINT AND SPACE  

E-print Network

CRYSTALLOGRAPHIC POINT AND SPACE GROUPS Andy Elvin June 10, 2013 #12;Contents Point and Space no reflection axes #12;Cube and Octahedron are dual Symmetries under Oh #12;Space Groups Subgroups of E(3) Point Group + Translation { R | 0 }{ E | t }a = { R | t }a = Ra + t 230 Space Groups 73 symmorphic space

California at Santa Cruz, University of

253

Efficient photocurrent generation by self-assembled monolayers composed of 3 10-helical peptides carrying linearly spaced naphthyl groups at the side chains.  

PubMed

Self-assembled monolayers (SAMs) were prepared on a gold substrate from a 310-helical peptide carrying three naphthyl groups at the side chain (SSN3B) or from the reference peptides carrying no or one naphthyl group. The 310-helical conformation of SSN3B in solution was confirmed by 1H NMR spectroscopy and geometry optimization. Cyclic voltammetry and infrared absorption-reflection spectroscopy showed vertical molecular orientation and a well-packed structure in the SSN3B SAM. Anodic photocurrent was successfully generated by the SSN3B SAM in the presence of triethanolamine, and the current intensity was found to be much larger than those by the other SAMs from peptides carrying one naphthyl group. It was therefore concluded that the linearly spaced naphthyl groups along the helical axis act as photosensitizer and electron-hopping site to promote photocurrent generation remarkably. PMID:15469265

Yanagisawa, Kazuyuki; Morita, Tomoyuki; Kimura, Shunsaku

2004-10-13

254

EXPERIENCE WITH TABLET PC VIDEO BASED HYBRID COURSEWORK IN  

E-print Network

EXPERIENCE WITH TABLET PC VIDEO BASED HYBRID COURSEWORK IN COMPUTER SCIENCE Jaspal Subhlok, Olin Keywords: Hybrid Learning, Online Learning, Video Lectures, Tablet PC Abstract Online learning, defined classroom interaction is detrimental to learning. Employing Tablet PCs with slide presentation

Subhlok, Jaspal

255

Polycomb group and trithorax group proteins in Arabidopsis  

Microsoft Academic Search

Polycomb group (PcG) and trithorax group (trxG) proteins form molecular modules of a cellular memory mechanism that maintains gene expression states established by other regulators. In general, PcG proteins are responsible for maintaining a repressed expression state, whereas trxG proteins act in opposition to maintain an active expression state. This mechanism, first discovered in Drosophila and subsequently in mammals, has

Stéphane Pien; Ueli Grossniklaus

2007-01-01

256

Remote facility sharing with ATM networks [PC based ATM Link Delay Simulator (LDS)]. Final report  

SciTech Connect

The ATM Link Delay Simulator (LDS) adds propagation delay to the ATM link on which it is installed, to allow control of link propagation delay in network protocol experiments simulating an adjustable piece of optical fiber. Our LDS simulates a delay of between 1.5 and 500 milliseconds and is built with commodity PC hardware, only the ATM network interface card is not generally available. Our implementation is special in that it preserves the exact spacing of ATM data cells a feature that requires sustained high performance. Our implementation shows that applications demanding sustained high performance are possible on commodity PC hardware. This illustrates the promise that PC hardware has for adaptability to demanding specialized testing of high speed network.

Kung, H. T.

2001-06-01

257

Magnetic properties of copper hexadecaphthalocyanine (F16CuPc) thin films and powders  

NASA Astrophysics Data System (ADS)

The structural and magnetic properties of F16CuPc thin films and powder, including x-ray diffraction (XRD), superconducting quantum interference device (SQUID) magnetometry, and theoretical modelling of exchange interactions are reported. Analysis of XRD from films, with thickness ranging between 100 and 160 nm, deposited onto Kapton and a perylene-3,4,9,10-tetracarboxylic-3,4,9,10-dianhydride (PTCDA) interlayer shows that the stacking angle (defined in the text) of the film is independent of the thickness, but that the texture is modified by both film thickness and substrate chemistry. The SQUID measurements suggest that all samples are paramagnetic, a result that is confirmed by our theoretical modelling including density functional theory calculations of one-dimensional molecular chains and Green's function perturbation theory calculations for a molecular dimer. By investigating theoretically a range of different geometries, we predict that the maximum possible exchange interaction between F16CuPc molecules is twice as large as that in unfluorinated copper-phthalocyanine (CuPc). This difference arises from the smaller intermolecular spacing in F16CuPc. Our density functional theory calculation for isolated F16CuPc molecule also shows that the energy levels of Kohn-Sham orbitals are rigidly shifted ˜1 eV lower in F16CuPc compared to CuPc without a significant modification of the intra-molecular spin physics, and that therefore the two molecules provide a suitable platform for independently varying magnetism and charge transport.

Wu, Wei; Rochford, L. A.; Felton, S.; Wu, Zhenlin; Yang, J. L.; Heutz, S.; Aeppli, G.; Jones, T. S.; Harrison, N. M.; Fisher, A. J.

2013-01-01

258

The role of compressional Pc5 pulsations in modulating precipitation of energetic electrons  

NASA Astrophysics Data System (ADS)

Pc5 (1.67-6.67 mHz) magnetic pulsations and the modulation of energetic electron precipitation are often observed simultaneously in the morning auroral-latitude data. Here we have investigated a conjunction event of Cluster spacecraft and Canadian auroral-latitude ground stations to identify the role of compressional Pc5 pulsations in modulating precipitation of energetic electrons observed by ground-based riometers. On 7 December 2002 as the spacecraft moved between L = 4.0 and 6.5 in the dawn sector (0600-0700 magnetic local time (MLT)), we found a monochromatic Pc5 magnetic pulsation at ~4.0 mHz simultaneously in space and on the ground. Both Cluster and ground magnetometer data confirmed that the resonant oscillation at 4.0 mHz occurred around L = ~6.0. Simultaneously, the four Cluster spacecraft identified the compressional Pc5, which was accompanied by similar temporal variations of the fluxes of medium energy (tens to hundreds of keV) electrons and of the intensity of whistler mode chorus waves. While the compressional Pc5 was present in the magnetosphere, the riometers near the spacecraft footprint observed the coincident modulation of electron precipitation at ~4.0 mHz. Our coordinated observations indicate a convincing relationship between compressional Pc5 magnetic pulsations in the magnetosphere and the modulation of electron precipitation in the ionosphere, mediated by chorus waves modulated in the magnetosphere, as predicted by the theory of Coroniti and Kennell []. Around the resonant shell, however, some additional contributions to the modulation of electron precipitation might also come from the effects of the resonant Pc5 oscillation.

Motoba, T.; Takahashi, K.; Gjerloev, J.; Ohtani, S.; Milling, D. K.

2013-12-01

259

Facilitating change Tablet PC trials across two distance education focused  

E-print Network

1/7/2011 1 Facilitating change ­ Tablet PC trials across two distance education focused@swin.edu.au Wendy Fisher The Open University W.A.Fisher@open.ac.uk How this paper was conceived · Tablet PC trial at the Open University (OU). Focus on marking. Publications. · Tablet PC trial at the University of Southern

Loch, Birgit

260

The USL NASA PC R and D development environment standards  

NASA Technical Reports Server (NTRS)

The development environment standards which have been established in order to control usage of the IBM PC/XT development systems and to prevent interference between projects being currently developed on the PC's are discussed. The standards address the following areas: scheduling PC resources; login/logout procedures; training; file naming conventions; hard disk organization; diskette care; backup procedures; and copying policies.

Dominick, Wayne D. (editor); Moreau, Dennis R.

1984-01-01

261

39 CFR 501.16 - PC postage payment methodology.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false PC postage payment methodology. 501.16 Section 501.16 Postal Service UNITED...POSTAGE EVIDENCING SYSTEMS § 501.16 PC postage payment methodology. (a) The PC Postage customer is permitted to...

2010-07-01

262

Lateral Impacts to PC Girders in Bridges with Intermediate Diaphragms  

Microsoft Academic Search

Bridge engineers are concerned about the response of PC girder bridges which are hit by over- height-vehicle loads. The roll of intermediate diaphragms in providing impact-damage protection to the PC girders is not clearly defined. An analytical study was conducted to assess the role of intermediate diaphragms in reducing the damage to the girders of a PC girder bridge that

Robert Abendroth; Fouad Fanous

2003-01-01

263

Themed Space  

ERIC Educational Resources Information Center

This article presents a classroom activity that introduces students to the concept of themed space. Students learn to think critically about the spaces they encounter on a regular basis by analyzing existing spaces and by working in groups to create their own themed space. This exercise gives students the chance to see the relevance of critical…

Lynch, Christopher O.

2010-01-01

264

Transient photocurrent measurements of PCDTBT:PC70BM and PCPDTBT:PC70BM Solar Cells: Evidence for charge trapping in efficient polymer/fullerene blends  

NASA Astrophysics Data System (ADS)

We report measurements of the turn-on and turn-off photocurrent dynamics as a function of applied voltage for efficient polymer/fullerene bulk heterojunction solar cells composed of poly[N-9?-hepta-decanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole) (PCDTBT): [6,6]-phenyl C71-butyric acid methyl ester (PC70BM) and poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT):PC70BM blends. In particular we present evidence for charge trapping that facilitates recombination in these systems. For the PCDTBT:PC70BM system, an initial transient photocurrent peak 5-10 ?s after turn-on is observed for operating voltages between 0.5 V and open-circuit. Furthermore, a long photocurrent tail is observed in the decay dynamics of PCDTBT:PC70BM devices with charge still being extracted hundreds of microseconds after turn-off. These features in the PCDTBT:PC70BM device are attributed to trapping and detrapping of charge on the microsecond time scale, with charge trapping facilitating recombination either through trap-assisted recombination or space-charge effects. For the PCPDTBT:PC70BM system, evidence for charge trapping is also observed albeit on a faster time scale. No initial transient photocurrent peak is observed, however the faster PCPDTBT:PC70BM decay dynamics show only a weak voltage dependence consistent with rapid trapping and recombination of charge. For both systems the amount of extracted charge as a function of applied voltage follows a similar form to the measured current-voltage curves providing evidence that photocurrent is hampered by the extraction, and not just the separation, of charge in these systems. The origin of charge trapping and the nature of recombination is discussed, along with the influence of additives on charge transport in the PCPDTBT:PC70BM system.

Li, Zhe; McNeill, Christopher R.

2011-04-01

265

Report from the MPP Working Group to the NASA Associate Administrator for Space Science and Applications. Technical memorandum report, 1 October 1985-30 September 1986  

SciTech Connect

NASA's Office of Space Science and Applications (OSSA) gave a select group of scientists the opportunity to test and implement their computational algorithms on the Massively Parallel Processor (MPP) located at Goddard Space Flight Center, beginning in late 1985. One year later, the Working Group presented its report, which addressed the following: algorithms, programming languages, architecture, programming environments, the way theory relates, and performance measured. The findings point to a number of demonstrated computational techniques for which the MPP architecture is ideally suited. For example, besides executing much faster on the MPP than on conventional computers, systolic VLSI simulation (where distances are short), lattice simulation, neural network simulation, and image problems were found to be easier to program on the MPP's architecture than on a CYBER 205 or even a VAX. The report also makes technical recommendations covering all aspects of MPP use, and recommendations concerning the future of the MPP and machines based on similar architectures, expansion of the Working Group, and study of the role of future parallel processors for space station, EOS, and the Great Observatories era.

Fischer, J.R.; Grosch, C.; Mcanulty, M.; Odonnell, J.; Storey, O.

1987-11-01

266

S-PC: an e-treatment application for management of smoke-quitting patients.  

PubMed

The main objective of this paper is to present a new program that facilitates the management of people who want to quit smoking, implemented through an e-treatment software called S-PC (Smoker Patient Control). S-PC is a web-based application that manages groups of patients, provides a bidirectional communication through mobile text messages and e-mails between patients and clinicians and offers advice and control to keep track of the patients and their status. A total of 229 patients were enrolled in the study, randomly divided into two groups, although some variables were tested to ensure that there were no significant differences between the groups that could have an impact on the outcome of the treatment. There were no significant differences between the two groups regarding the ratio/number of males/females, tobacco dependence, co-oximetry, average cigarette consumption, current age and age when smoking started. The first group was made up of 104 patients (45.4% of the total) and followed a treatment that incorporated the S-PC tool, while the second one had 125 patients without the S-PC tool. S-PC was evaluated for its effectiveness at assisting the patients to give up smoking, and its effect on clinician time management. 74% of the S-PC group completed the treatment without relapses and remained abstinent three months after the completion of the treatment, understanding abstinence as being continuous (with no relapses allowed and co-oximetry below 1 ppm) from the day of stopping. In contrast only 45.6% of the No S-PC group completed the treatment without relapses and remained abstinent three months after completion of the treatment. The rate of admittance to the program has doubled in one year and patients went from having to wait for 3 months to be immediately admitted into the program. This therapeutic e-health program aims at maximizing the number of patients that a professional can effectively help to quit smoking. In addition, the system also detects patients who are not progressing appropriately, allowing the professional to improve their treatment parameters dynamically. PMID:24742965

Vilaplana, Jordi; Solsona, Francesc; Abella, Francesc; Cuadrado, Josep; Alves, Rui; Mateo, Jordi

2014-06-01

267

Reverse rectification behavior of NiPc (p-type)/F16CuPc (n-type) heterojunction  

NASA Astrophysics Data System (ADS)

In this paper we present reverse rectification behavior of an organic heterojunction comprising of nickel phthalocyanine (NiPc) and copper-hexadecafluroro-phthalocyanine (F16CuPc) grown by MBE. Using Kelvin Probe we found that charge is accumulated at both side of interface, electrons in F16CuPc and holes in NiPc. The thickness of charge accumulated at the interface is about 20 nm. Based on Kelvin Probe data, mechanism of reverse rectification is explained.

Kumar, Arvind; Samanta, Soumen; Singh, Ajay; Debnath, A. K.; Prasad, R.; Aswal, D. K.; Gupta, S. K.

2012-06-01

268

PC Magazine: The Future of Technology  

NSDL National Science Digital Library

This section of PC Magazine's Web site highlights some of the most fascinating and potentially revolutionary technologies that could be on the verge of large scale development. Of the nineteen main technologies that are featured, some have been widely publicized, such as hydrogen fuel cells and grid computing. Others are not as well known. For example, the article on e-bombs, or "high-power microwave (HPM) weapons," touches on a US Department of Defense effort that until recently has been shrouded in secrecy. A prototype gallery is also available on this site, showing images and brief descriptions of other remarkable technologies.

269

IBM PC/IX operating system evaluation plan  

NASA Technical Reports Server (NTRS)

An evaluation plan for the IBM PC/IX Operating System designed for IBM PC/XT computers is discussed. The evaluation plan covers the areas of performance measurement and evaluation, software facilities available, man-machine interface considerations, networking, and the suitability of PC/IX as a development environment within the University of Southwestern Louisiana NASA PC Research and Development project. In order to compare and evaluate the PC/IX system, comparisons with other available UNIX-based systems are also included.

Dominick, Wayne D. (editor); Granier, Martin; Hall, Philip P.; Triantafyllopoulos, Spiros

1984-01-01

270

Group-theoretical approach to the construction of bases in 2{sup n}-dimensional Hilbert space  

SciTech Connect

We propose a systematic procedure to construct all the possible bases with definite factorization structure in 2{sup n}-dimensional Hilbert space and discuss an algorithm for the determination of basis separability. The results are applied for classification of bases for an n-qubit system.

Garcia, A.; Romero, J. L.; Klimov, A. B., E-mail: klimov@cencar.udg.mx [Universidad de Guadalajara, Departamento de Fisica (Mexico)

2011-06-15

271

Effects of row spacing, seed rate and maturity group on late planted soybean under irrigated and dryland  

E-print Network

to decrease. This purpose of this study is determine the best planting strategies in regards to row spacing varieties (REV 48R22 and AG 5632) used in the study were glyphosate-resistant and were selected based were determined. All harvested #12;plots were collected in bags to determine seed mass. Results

Balasundaram, Balabhaskar "Baski"

272

Talk in Blended-Space Speech Communities: An Exploration of Discursive Practices of a Professional Development Group  

ERIC Educational Resources Information Center

This study is an exploration of alternative teacher professional development. While using symbolic interactionism for a research lens, it characterizes the discursive practices commonly found in formal, informal, and blended-space speech communities based on the talk within a leadership-development program comprised of five female, church-based…

Garvin, Tabitha Ann

2011-01-01

273

Space, time and the pattern of individual associations in a group-living species: Sanderlings have no friends  

Microsoft Academic Search

The persistence of flock membership through time and space was examined for wintering sanderlings Calidris alba at Bodega Bay, California from October 1978 to March 1981. Observed patterns of association were then compared with those expected from a null model: that the set of birds within a given flock represent a random sample from the local population.

J. P. Myers

1983-01-01

274

Is $J^{PC}=3^{-+}$ molecule possible?  

E-print Network

The confirmation of charged charmonium-like states indiates that heavy quark molecules should exist. We here discuss the possibility of a molecule state with $J^{PC}=3^{-+}$. In a one-boson-exchange model investigation for the S wave $C=+$ $D^*\\bar{D}_2^*$ states, one finds that the strongest attraction is in the case $J=3$ and $I=0$ for both $\\pi$ and $\\sigma$ exchanges. Numerical analysis indicates that this hadronic bound state might exist if a phenomenological cutoff parameter around 2.3 GeV (1.5 GeV) is reasonable with a dipole (monopole) type form factor in the one-pion-exchange model. The cutoff for binding solutions may be reduced to a smaller value once the $\\sigma$ exchange contribution is included. If a state around the $D^*\\bar{D}_2^*$ threshold ($\\approx$4472 MeV) in the channel $J/\\psi\\omega$ (P wave) is observed, the heavy quark spin symmetry implies that it is not a $c\\bar{c}$ meson and the $J^{PC}$ are likely to be $3^{-+}$.

W. Zhu; Yan-Rui Liu; T. Yao

2014-06-04

275

Evaluating security systems using SNAP-PC  

SciTech Connect

SNAP-PC (Safeguards Network Analysis Procedure for the Personal Computer) is a user-friendly version of SNAP designed for IBM XT or AT compatible microcomputers. SNAP is a simulation-based analysis technique supporting the evaluation of fixed-site security systems to prevent theft or sabotage of a specified target. Through SNAP the user is able to define the facility, the sensor system, the guard operating policies and response tactics, and the adversary's attack plan. SNAP uses the system definition to analyze its effectiveness in defending against specific threats. The system performance statistics measured by SNAP include: Adversary mission success probability, guard and adversary casualties, duration of engagements, outcome of engagements, duration of scenario by outcome (adversary success/fail), and adversary duration by facility location. The SNAP-PC package provides a compact analysis tool that can be used to analyze a wide variety of security systems. It places SNAP, a proven evaluation technique, in the hands of on-site personnel, not just computer analysts. The support programs eliminate the labor intensive tedious task of organizing and sorting through reams of output reports and greatly reduce the time previously required to analyze a security system.

Tobin, C.D.; Gregg, M.L.; Erdbruegger, M.R.

1986-08-01

276

Association of trxG and PcG proteins with the bxd maintenance element depends on transcriptional activity.  

PubMed

Polycomb group (PcG) and trithorax group (trxG) proteins act in an epigenetic fashion to maintain active and repressive states of expression of the Hox and other target genes by altering their chromatin structure. Genetically, mutations in trxG and PcG genes can antagonize each other's function, whereas mutations of genes within each group have synergistic effects. Here, we show in Drosophila that multiple trxG and PcG proteins act through the same or juxtaposed sequences in the maintenance element (ME) of the homeotic gene Ultrabithorax. Surprisingly, trxG or PcG proteins, but not both, associate in vivo in any one cell in a salivary gland with the ME of an activated or repressed Ultrabithorax transgene, respectively. Among several trxG and PcG proteins, only Ash1 and Asx require Trithorax in order to bind to their target genes. Together, our data argue that at the single-cell level, association of repressors and activators correlates with gene silencing and activation, respectively. There is, however, no overall synergism or antagonism between and within the trxG and PcG proteins and, instead, only subsets of trxG proteins act synergistically. PMID:18550707

Petruk, Svetlana; Smith, Sheryl T; Sedkov, Yurii; Mazo, Alexander

2008-08-01

277

Ranging pattern and use of space in a group of red howler monkeys (Alouatta seniculus) in a southeastern Colombian rainforest.  

PubMed

We studied a group of red howler monkeys (Alouatta seniculus) bordering a lake in an eastern Colombian Amazon rainforest for 10 months. The group used an area of 182 ha located mainly on Pleistocene terrace forest and had no overlap with other howler home ranges. Home range use varied through the year as a consequence of fruit and leaf abundance. For example, during the fruit scarcity season the group used an area of flooded forest nearly exclusively, indicating that at least for a portion of the year they are habitat specialists. Two areas intensively used by the group were identified, representing 17.6 % of the home range, and within which 56.9 % of the feeding trees were located. Overall density of feeding trees within the group's home range was very low (1.12 trees/ha). Home range size, as well as mean length of daily ranges (1,150 m), is the largest reported for this species to date, and it is likely a consequence of the diminished productivity of the plant communities on poor soil. Our results give an interesting example of the ranging behavior of this primate, which clearly differs from previous descriptions of red howlers. PMID:11748695

Palacios, E; Rodriguez, A

2001-12-01

278

Different Polycomb group complexes regulate common target genes in Arabidopsis  

Microsoft Academic Search

Polycomb group (PcG) proteins convey epigenetic inheritance of repressed transcriptional states. Although the mechanism of the action of PcG is not completely understood, methylation of histone H3 lysine 27 (H3K27) is important in establishing PcG-mediated transcriptional repression. We show that the plant PcG target gene PHERES1 is regulated by histone trimethylation on H3K27 residues mediated by at least two different

Grigory Makarevich; Olivier Leroy; Umut Akinci; Daniel Schubert; Oliver Clarenz; Justin Goodrich; Ueli Grossniklaus; Claudia Köhler

2006-01-01

279

A scientific program for infrared, submillimeter and radio astronomy from space: A report by the Management Operations Working Group  

NASA Technical Reports Server (NTRS)

Important and fundamental scientific progress can be attained through space observations in the wavelengths longward of 1 micron. The formation of galaxies, stars, and planets, the origin of quasars and the nature of active galactic nuclei, the large scale structure of the Universe, and the problem of the missing mass, are among the major scientific issues that can be addressed by these observations. Significant advances in many areas of astrophysics can be made over the next 20 years by implementing the outlined program. This program combines large observatories with smaller projects to create an overall scheme that emphasized complementarity and synergy, advanced technology, community support and development, and the training of the next generation of scientists. Key aspects of the program include: the Space Infrared Telescope Facility; the Stratospheric Observatory for Infrared Astronomy; a robust program of small missions; and the creation of the technology base for future major observatories.

1989-01-01

280

Irregular structure of thermal ion plasma near the plasmapause observed from Ogo 3 and Pc 1 measurements.  

NASA Technical Reports Server (NTRS)

Independent measurements of the plasmapause and associated thermal plasma structure from Ogo 3 are compared with ground-based Pc 1 observations from the period 1966-67. Substantial agreement between the plasmapause crossing identified on the satellite and the Pc 1 occurrence positions observed on the ground at midlatitudes during the nighttime (including dawn and dusk) indicates that these nighttime Pc 1 events are closely associated with the plasmapause. A correlation of selected closely spaced events obtained in the nighttime under quiet to moderate activity provides good agreement in the proton concentrations near the plasmapause boundary. Preliminary results indicate Pc 1 excitation is associated with plasma irregularities near the plasmapause and is particularly favorable in the region of 'post-storm recovery' and in the region of diurnal 'plasma bulge' in the afternoon-dusk sector.

Kikuchi, H.; Taylor, H. A., Jr.

1972-01-01

281

PC-based Multiple Information System Interface (PC/MISI) detailed design and implementation plan  

NASA Technical Reports Server (NTRS)

The design plan for the personal computer multiple information system interface (PC/MISI) project is discussed. The document is intended to be used as a blueprint for the implementation of the system. Each component is described in the detail necessary to allow programmers to implement the system. A description of the system data flow and system file structures is given.

Dominick, Wayne D. (editor); Hall, Philip P.

1985-01-01

282

Disk-based k-mer counting on a PC  

PubMed Central

Background The k-mer counting problem, which is to build the histogram of occurrences of every k-symbol long substring in a given text, is important for many bioinformatics applications. They include developing de Bruijn graph genome assemblers, fast multiple sequence alignment and repeat detection. Results We propose a simple, yet efficient, parallel disk-based algorithm for counting k-mers. Experiments show that it usually offers the fastest solution to the considered problem, while demanding a relatively small amount of memory. In particular, it is capable of counting the statistics for short-read human genome data, in input gzipped FASTQ file, in less than 40 minutes on a PC with 16 GB of RAM and 6 CPU cores, and for long-read human genome data in less than 70 minutes. On a more powerful machine, using 32 GB of RAM and 32 CPU cores, the tasks are accomplished in less than half the time. No other algorithm for most tested settings of this problem and mammalian-size data can accomplish this task in comparable time. Our solution also belongs to memory-frugal ones; most competitive algorithms cannot efficiently work on a PC with 16 GB of memory for such massive data. Conclusions By making use of cheap disk space and exploiting CPU and I/O parallelism we propose a very competitive k-mer counting procedure, called KMC. Our results suggest that judicious resource management may allow to solve at least some bioinformatics problems with massive data on a commodity personal computer. PMID:23679007

2013-01-01

283

(TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8]/CuPc two-component bilayer heterojunction-based organic transistors with high ambipolar performance.  

PubMed

Organic thin film transistor (OTFT) devices fabricated by the solution-based QLS technique from a mixed (phthalocyaninato)(porphyrinato) europium complex (TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8] exhibit air-stable ambipolar performance with mobilities of 6.0 × 10(-5) cm(2) V(-1) s(-)1 for holes and 1.4 × 10(-4) cm(2) V(-1) s(-1) for electrons, respectively. In good contrast, the two-component bilayer heterojunction thin film devices constructed by directly growing (TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8] on vacuum deposited (VCD) CuPc film using solution based QLS method were revealed to show unprecedented ambipolar performance with carrier mobilities of 0.16 cm(2) V(-1) s(-1) for holes and 0.30 cm(2) V(-1) s(-1) for electrons. In addition to the intrinsic role of p-type organic semiconductor, the VCD CuPc film on the substrate also acts as a good template that induces significant improvement over the molecular ordering of triple-decker compound in the film. In particular, it results in the change in the aggregation mode of (TFPP)Eu[Pc(OPh)8]Eu[Pc(OPh)8] from J-type in the single-layer film to H-type in the bilayer film according to the UV-vis, XRD, and AFM observations. PMID:25599852

Gao, Dameng; Zhang, Xia; Kong, Xia; Chen, Yanli; Jiang, Jianzhuang

2015-02-01

284

Materials accounting system for an IBM PC  

SciTech Connect

We have adapted the Los Alamos MASS accounting system for use on an IBM PC/AT at the Fuels Manufacturing Facility (FMF) at Argonne National Laboratory-West (ANL-WEST) in Idaho Falls, Idaho. Cost of hardware and proprietary software was less than $10,000 per station. The system consists of three stations between which accounting information is transferred using floppy disks accompanying special nuclear material shipments. The programs were implemented in dBASEIII and were compiled using the proprietary software CLIPPER. Modifications to the inventory can be posted in just a few minutes, and operator/computer interaction is nearly instantaneous. After the records are built by the user, it takes 4 to 5 seconds to post the results to the database files. A version of this system was specially adapted and is currently in use at the FMF facility at Argonne National Laboratory in Idaho Falls. Initial satisfaction is adequate and software and hardware problems are minimal.

Bearse, R.C.; Thomas, R.J.; Henslee, S.P.; Jackson, B.G.; Tracy, D.B.; Pace, D.M.

1986-01-01

285

Human 17?-hydroxysteroid dehydrogenase-ligand complexes: crystals of different space groups with various cations and combined seeding and co-crystallization  

NASA Astrophysics Data System (ADS)

Human estrogenic 17?-hydroxysteroid dehydrogenase (17?-HSD1) is responsible for the synthesis of active estrogens that stimulate the proliferation of breast cancer cells. The enzyme has been crystallized using a Mg 2+/PEG (3500)/?-octyl glucoside system [Zhu et al., J. Mol. Biol. 234 (1993) 242]. The space group of these crystals is C2. Here we report that cations can affect 17?-HSD1 crystallization significantly. In the presence of Mn 2+ instead of Mg 2+, crystals have been obtained in the same space group with similar unit cell dimensions. In the presence of Li + and Na + instead of Mg 2+, the space group has been changed to P2 12 12 1. A whole data set for a crystal of 17ß-HSD1 complex with progesterone grown in the presence of Li + has been collected to 1.95 Å resolution with a synchrotron source. The cell dimensions are a=41.91 Å, b=108.21 Å, c=117.00 Å. The structure has been preliminarily determined by molecular replacement, yielding important information on crystal packing in the presence of different cations. In order to further understand the structure-function relationship of 17?-HSD1, enzyme complexes with several ligands have been crystallized. As the steroids have very low aqueous solubility, we used a combined method of seeding and co-crystallization to obtain crystals of 17?-HSD1 complexed with various ligands. This method provides ideal conditions for growing complex crystals, with ligands such as 20?-hydroxysteroid progesterone, testosterone and 17?-methyl-estradiol-NADP +. Several complex structures have been determined with reliable electronic density of the bound ligands.

Zhu, D.-W.; Han, Q.; Qiu, W.; Campbell, R. L.; Xie, B.-X.; Azzi, A.; Lin, S.-X.

1999-01-01

286

Architectural implications of hardware-accelerated bucket rendering on the PC  

Microsoft Academic Search

Wrcket rendering is a technique whereby a scene is sorted into screen-space tiles and each tile is rendered independently in turn, We expect hardware-accelerated bucket rendering to become available on the PC, and in this paper we explore the effect of such accelerators on main memory bandwidth, bus bandwidth to the accelerator, and on increased triangle set-up requirements. The most

Michael Cox; Narendra Bhandari

1997-01-01

287

Pearl structures of Pc1 geomagnetic pulsations observed at multipoint ground stations at Russia, Japan and Canada  

NASA Astrophysics Data System (ADS)

Pc1 geomagnetic pulsations propagate from high to low latitudes through the ionospheric wave duct. A few papers had shown longitudinal propagation of Pc1 pulsations [e.g., Kawamura et al. 1981; Sakaguchi et al.2012]. Despite these previous researches, diurnal variations of longitudinally-distributed Pc1 pulsations and the pearl structures at different stations have not been investigated yet. In order to understand generation and propagation processes of Pc1 pulsations in the magnetosphere and the ionosphere, it is necessary to investigate spatial distribution of Pc1 pulsations using magnetometers at longitudinally and latitudinally separated ground stations. We have investigated spatial distributions of the Pc1 pulsations observed by induction magnetometers at three ground stations at Moshiri (MOS) in Japan, Magadan (MGD) in far-eastern Russia and Athabasca (ATH) in central Canada from January 2009 to December 2011. Simultaneous Pc1 events observed at MGD and ATH occurred in the morning and afternoon sectors. This result is consistent with the global distribution of EMIC waves observed in space [Min et al. 2012]. The simultaneous Pc1 events with high coherence (> 0.5) observed at ATH and MGD concentrates in the afternoon to pre-midnight sector. The Pc1 frequencies of the simultaneous Pc1 events at ATH and MGD in the afternoon to pre-midnight sector were higher than those in the post-midnight to morning sector. Most of the simultaneous Pc1 events with high coherence observed at ATH and MGD have different pearl structures. This result indicates that the pearl structures should be not caused in the magnetosphere, and rather made during the propagation in the ionospheric duct. Simultaneous Pc1 events observed at MGD and MOS at subauroral and middle latitudes, respectively, were most frequently observed at night suggesting that propagation in the ionospheric duct suffers less attenuation at night. In the presentation we discuss these results in combination with the EMIC wave distribution in the magnetosphere and their propagation to the ionosphere and in the ionospheric duct.

Jun, C.; Shiokawa, K.; Connors, M. G.; Schofield, I.; Poddelsky, I.; Shevtsov, B.

2013-12-01

288

Toward the optimization of PC-based training  

Microsoft Academic Search

Since 1992, the National Space Development Agency of Japan (NASDA) and the Economic and Social Commission for Asia and the Pacific (ESCAP) have been co-organising the Regional Remote Sensing Seminar on Tropical Ecosystem Management (Program Chairman: Prof. Shunji Murai) every year in some country in Asia. In these seminars, the members of the ISPRS Working Group VI\\/2 ‘Computer Assisted Teaching’

Kohei Cho; Shunji Murai

1997-01-01

289

The solar-eclipse effect on Pc3 geomagnetic pulsations  

NASA Astrophysics Data System (ADS)

It is demonstrated that the effect of a solar eclipse (e.g., that of July 31, 1981) on Pc3 pulsations is manifested in a decrease of their amplitude, which is evidently connected with the screening of ionizing radiation during the eclipse. The eclipse effect can be identified according to the global modulation of the Pc3 amplitude by the IMF orientation; changes in Pc3 intensity due to local effects can be determined according to the amplitude ratio of two stations in different eclipse zones. The degree of the eclipse effect on the Pc3 amplitude for the different stations depends on the eclipse phase.

Bolshakova, O. V.; Kurazhkovskaia, N. A.; Troitskaia, V. A.

1987-02-01

290

Exact hairy black brane solutions in 5D anti-de Sitter space and holographic renormalization group flows  

NASA Astrophysics Data System (ADS)

We construct a general class of exact regular black hole solutions with toroidal horizon topology in five-dimensional anti-de Sitter gravity with a self-interacting scalar field. With these boundary conditions and due to the nontrivial backreaction of the scalar field, the no-hair theorems can be evaded so that an event horizon can be formed. The scalar field is regular everywhere outside the curvature singularity and it vanishes at the boundary where the potential is finite. We study the properties of these black holes in the context of AdS/CFT duality and comment on the dual operators, which saturate the unitarity bound. We present exact expressions for the beta function and construct a c-function that characterizes the renormalization-group flow.

Aceña, Andrés; Anabalón, Andrés; Astefanesei, Dumitru

2013-06-01

291

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION BRITISH NATIONAL SPACE CENTRE  

E-print Network

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION­ BRITISH NATIONAL SPACE CENTRE JOINT WORKING GROUP ................................................................................................................ 14 6. UK PPP for NASA Commercial Development

Crowther, Paul

292

Identifying wide, cold planets within 8pc  

NASA Astrophysics Data System (ADS)

Direct imaging exoplanet studies have recently unveiled a previously-unexpected population of massive planets (up to 15 M_Jup) in wide orbits (>100AU). Although most of these discoveries have been around younger stars and have been of similar temperatures to field brown dwarfs, one object (WD 0806-661B), is the coldest planet known outside our solar system. We propose a survey of all stars and brown dwarfs within 8pc to identify massive planetary companions in the 150-1500AU separation range. We will 1) Measure the fraction of wide planetary mass companions to stars in the Solar neighbourhood. 2) Identify all planets within 8 parsecs with masses above 8 Jupiter masses in our chosen projected separation range with lower mass limits for closer and younger stars. 3) Identify approximately 8 planets, four of which will have temperatures below 300K making them ideal targets to study water clouds in cold atmospheres with both JWST and the next generation of ground-based extremely large telescopes. Our survey will be the most complete survey for wide planets to-date and will provide both a measurement of the wide planet population and a legacy of cold, well constrained targets for future observatories.

Deacon, Niall; Kraus, Adam; Crossfield, Ian

2014-12-01

293

Major/Department PC Mac Tablet Notes College of Engineering  

E-print Network

Software Major/Department PC Mac Tablet Notes College of Engineering and Physical Sciences (CEPS: Recommend 4GB+ RAM, all platforms Tablets: Not recommended as primary device. Check with professors on classroom tablet policies. All students: Microsoft Office suite Current versions are Office 2013 for PC

294

Image baby image!: making pc cloning more efficient  

Microsoft Academic Search

The task of imaging lab computers can be a complicated and manual process. University of Calgary Information Technologies Lab Services (IT Lab Services) has endeavored to streamline this process by developing an in-house system. This system addresses the issues of collecting inventory information, loading an image on to a PC, and configuring the PC after imaging. A custom version of

Carol Sin; Danny Wong

2007-01-01

295

PC-based test systems in harsh environment  

Microsoft Academic Search

PC based test systems are typically used in office and laboratory environments. Some systems can also be used in industrial environments where electrical noise, higher temperature, and dust prevent the use of the desktop PC. These test systems however will not survive the harsh environment found on the flight-line or otherwise outdoor use. Such harsh environment conditions include extreme ambient

L. A. Gutterman

1999-01-01

296

Mouse vision: PC mouse control using neural networks  

NASA Astrophysics Data System (ADS)

We have developed a system to control the PC's Mouse using the ocular movement. This system allows incapacitated people use the PC for many purposes; on the other hand, this system is ideal to play virtual games due to its interactivity with the user.

Miranda, David; Silva, E.; Patino, A.

2004-10-01

297

PrPC from stem cells to cancer  

PubMed Central

The cellular prion protein PrPC was initially discovered as the normal counterpart of the pathological scrapie prion protein PrPSc, the main component of the infectious agent of Transmissible Spongiform Encephalopathies. While clues as to the physiological function of this ubiquitous protein were greatly anticipated from the development of knockout animals, PrP-null mice turned out to be viable and to develop without major phenotypic abnormalities. Notwithstanding, the discovery that hematopoietic stem cells from PrP-null mice have impaired long-term repopulating potential has set the stage for investigating into the role of PrPC in stem cell biology. A wealth of data have now exemplified that PrPC is expressed in distinct types of stem cells and regulates their self-renewal as well as their differentiation potential. A role for PrPC in the fate restriction of embryonic stem cells has further been proposed. Paralleling these observations, an overexpression of PrPC has been documented in various types of tumors. In line with the contribution of PrPC to stemness and to the proliferation of cancer cells, PrPC was recently found to be enriched in subpopulations of tumor-initiating cells. In the present review, we summarize the current knowledge of the role played by PrPC in stem cell biology and discuss how the subversion of its function may contribute to cancer progression. PMID:25364760

Martin-Lannerée, Séverine; Hirsch, Théo Z.; Hernandez-Rapp, Julia; Halliez, Sophie; Vilotte, Jean-Luc; Launay, Jean-Marie; Mouillet-Richard, Sophie

2014-01-01

298

Modelling of carbonation of PC and blended cement concrete  

Microsoft Academic Search

Presented herein is a numerical model to predict the carbonation depth of Portland cement (PC) and blended cement concrete under a wide range of environmental conditions. The improved model for hydration of PC and activity of blended cement is proposed and used in this carbonation model. This carbonation model can be used for concrete made of silica fume, fly ash

Sabet Divsholi Bahador; Jong Herman Cahyadi

2009-01-01

299

Melatonin suppression of PC12 cell growth and death  

Microsoft Academic Search

Melatonin has previously been reported to influence cell differentiation and growth in a number of cell culture systems in vitro. In this paper, we describe the effects of high pharmacological and low physiological concentrations of melatonin on cell growth in rat pheochromocytoma cells (PC12 cells). Melatonin produced a biphasic response with respect to cell growth in PC12 cells. At low

Jerome A Roth; Richard Rabin; Kimberly Agnello

1997-01-01

300

Transforming PC Power Supplies into Smart Car Battery Conditioners  

ERIC Educational Resources Information Center

This paper describes a laboratory project consisting of a PC power supply modification into an intelligent car-battery conditioner with both wireless and wired networking capabilities. Adding a microcontroller to an average PC power supply transforms it into a flexible, intelligent device that can be configured and that is suitable to keep car…

Rodriguez-Ascariz, J. M.; Boquete-Vazquez, L.

2011-01-01

301

Extracellular matrix allows PC12 neurite elongation in the absence of microtubules  

Microsoft Academic Search

Several groups have shown that PC12 will extend microtubule-containing neurites on extracellular matrix (ECM) with no lag period in the absence of nerve growth factor. This is in contrast to nerve growth factor (NGF)-induced neurite outgrowth that occurs with a lag period of several days. During this lag period, increased synthesis or activation of assembly-promoting microtubule-associated proteins (MAPs) occurs and

Phillip Lamoureux; Vivian L. Steel; Clara Regal; Lynne Adgate; Robert E. Buxbaum; Steven R. Heidemann

1990-01-01

302

Phosphorylation negatively regulates the function of coactivator PC4.  

PubMed Central

Human positive cofactor 4 (PC4) mediates activator-dependent transcription by RNA polymerase II, apparently through interactions with transcriptional activators and the basal transcription machinery. We report here that PC4 function is modulated by in vivo phosphorylation. Protein-protein interaction studies and in vitro transcription assays demonstrate that only the nonphosphorylated form of PC4 is functionally active. Although recombinant PC4 can be phosphorylated by casein kinase II and protein kinase C in vitro, mutational and mass spectrometric analyses suggest that the in vivo hyperphosphorylation of PC4 is mediated mainly by casein kinase II and restricted to an N-terminal serine-rich region. These observations provide one example of a transcriptional cofactor that is negatively regulated by casein kinase II phosphorylation. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:7809103

Ge, H; Zhao, Y; Chait, B T; Roeder, R G

1994-01-01

303

PC-SEAPAK - ANALYSIS OF COASTAL ZONE COLOR SCANNER AND ADVANCED VERY HIGH RESOLUTION RADIOMETER DATA  

NASA Technical Reports Server (NTRS)

PC-SEAPAK is a user-interactive satellite data analysis software package specifically developed for oceanographic research. The program is used to process and interpret data obtained from the Nimbus-7/Coastal Zone Color Scanner (CZCS), and the NOAA Advanced Very High Resolution Radiometer (AVHRR). PC-SEAPAK is a set of independent microcomputer-based image analysis programs that provide the user with a flexible, user-friendly, standardized interface, and facilitates relatively low-cost analysis of oceanographic satellite data. Version 4.0 includes 114 programs. PC-SEAPAK programs are organized into categories which include CZCS and AVHRR level-1 ingest, level-2 analyses, statistical analyses, data extraction, remapping to standard projections, graphics manipulation, image board memory manipulation, hardcopy output support and general utilities. Most programs allow user interaction through menu and command modes and also by the use of a mouse. Most programs also provide for ASCII file generation for further analysis in spreadsheets, graphics packages, etc. The CZCS scanning radiometer aboard the NIMBUS-7 satellite was designed to measure the concentration of photosynthetic pigments and their degradation products in the ocean. AVHRR data is used to compute sea surface temperatures and is supported for the NOAA 6, 7, 8, 9, 10, 11, and 12 satellites. The CZCS operated from November 1978 to June 1986. CZCS data may be obtained free of charge from the CZCS archive at NASA/Goddard Space Flight Center. AVHRR data may be purchased through NOAA's Satellite Data Service Division. Ordering information is included in the PC-SEAPAK documentation. Although PC-SEAPAK was developed on a COMPAQ Deskpro 386/20, it can be run on most 386-compatible computers with an AT bus, EGA controller, Intel 80387 coprocessor, and MS-DOS 3.3 or higher. A Matrox MVP-AT image board with appropriate monitor and cables is also required. Note that the authors have received some reports of incompatibilities between the MVP-AT image board and ZENITH computers. Also, the MVP-AT image board is not necessarily compatible with 486-based systems; users of 486-based systems should consult with Matrox about compatibility concerns. Other PC-SEAPAK requirements include a Microsoft mouse (serial version), 2Mb RAM, and 100Mb hard disk space. For data ingest and backup, 9-track tape, 8mm tape and optical disks are supported and recommended. PC-SEAPAK has been under development since 1988. Version 4.0 was updated in 1992, and is distributed without source code. It is available only as a set of 36 1.2Mb 5.25 inch IBM MS-DOS format diskettes. PC-SEAPAK is a copyrighted product with all copyright vested in the National Aeronautics and Space Administration. Phar Lap's DOS_Extender run-time version is integrated into several of the programs; therefore, the PC-SEAPAK programs may not be duplicated. Three of the distribution diskettes contain DOS_Extender files. One of the distribution diskettes contains Media Cybernetics' HALO88 font files, also licensed by NASA for dissemination but not duplication. IBM is a registered trademark of International Business Machines. MS-DOS is a registered trademark of Microsoft Corporation. HALO88 is a registered trademark of Media Cybernetics, but the product was discontinued in 1991.

Mcclain, C. R.

1994-01-01

304

YOUNG STARS NEAR EARTH: THE OCTANS-NEAR ASSOCIATION AND CASTOR MOVING GROUP  

SciTech Connect

All cataloged stellar moving groups and associations with ages ?100 Myr and within 100 pc of Earth have Galactic space motions (UVW) situated in a 'good box' with dimensions ?20 km s{sup –1} on a side. Torres et al. defined the Octans Association as a group of 15 stars with age '20 Myr?' and located ?140 pc from Earth, but with average V space velocity –3.6 km s{sup –1} that is well outside of the good box. We present a list of 14 Hipparcos star systems within 100 pc of Earth that we call {sup O}ctans-Near{sup ;} these systems have UVW similar to those of the much more distant Octans Association. The Octans-Near stars have apparent ages between about 30 and 100 Myr and their relationship to the Octans Association stars is unclear. Six additional star systems have UVW similar to those of Octans-Near stars and likely ages ?200 Myr. These six systems include the late-type binary star EQ Peg—6.2 pc from Earth with likely age ?100 Myr and thus likely to be the nearest known pre-main sequence star system. The UVW of stars in a previously proposed ?200 Myr old Castor moving group are not too dissimilar from the UVW of Octans-Near stars. However, stars in the Castor group—if it exists at all—are mostly substantially older than 200 Myr and thus generally can readily be distinguished from the much younger Octans-Near stars.

Zuckerman, B.; Vican, Laura [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Song, Inseok [Department of Physics and Astronomy, University of Georgia, Athens, GA 30602-2451 (United States); Schneider, Adam, E-mail: ben@astro.ucla.edu, E-mail: lvican@ucla.edu, E-mail: song@uga.edu, E-mail: Adam.Schneider@Utoledo.edu [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States)

2013-11-20

305

The Polycomb Group Protein EED Interacts with YY1, and Both Proteins Induce Neural Tissue in Xenopus Embryos  

Microsoft Academic Search

Polycomb group (PcG) proteins form multimeric protein complexes which are involved in the heritable stable repression of genes. Previously, we identified two distinct human PcG protein complexes. The EED-EZH protein complex contains the EED and EZH2 PcG proteins, and the HPC-HPH PcG complex contains the HPC, HPH, BMI1, and RING1 PcG proteins. Here we show that YY1, a homolog of

DAVID P. E. SATIJN; KARIEN M. HAMER; JAN DEN BLAAUWEN; ARIE P. OTTE

2001-01-01

306

HOTSPOT Health Physics codes for the PC  

SciTech Connect

The HOTSPOT Health Physics codes were created to provide Health Physics personnel with a fast, field-portable calculation tool for evaluating accidents involving radioactive materials. HOTSPOT codes are a first-order approximation of the radiation effects associated with the atmospheric release of radioactive materials. HOTSPOT programs are reasonably accurate for a timely initial assessment. More importantly, HOTSPOT codes produce a consistent output for the same input assumptions and minimize the probability of errors associated with reading a graph incorrectly or scaling a universal nomogram during an emergency. The HOTSPOT codes are designed for short-term (less than 24 hours) release durations. Users requiring radiological release consequences for release scenarios over a longer time period, e.g., annual windrose data, are directed to such long-term models as CAPP88-PC (Parks, 1992). Users requiring more sophisticated modeling capabilities, e.g., complex terrain; multi-location real-time wind field data; etc., are directed to such capabilities as the Department of Energy`s ARAC computer codes (Sullivan, 1993). Four general programs -- Plume, Explosion, Fire, and Resuspension -- calculate a downwind assessment following the release of radioactive material resulting from a continuous or puff release, explosive release, fuel fire, or an area contamination event. Other programs deal with the release of plutonium, uranium, and tritium to expedite an initial assessment of accidents involving nuclear weapons. Additional programs estimate the dose commitment from the inhalation of any one of the radionuclides listed in the database of radionuclides; calibrate a radiation survey instrument for ground-survey measurements; and screen plutonium uptake in the lung (see FIDLER Calibration and LUNG Screening sections).

Homann, S.G.

1994-03-01

307

PC viruses: How do they do that?  

SciTech Connect

The topic of PC Viruses has been an issue for a number of years now. They`ve been reported in every major newspaper, tabloids, television and radio. People from all fields get viruses: government, private sector businesses, home computers, schools, computer software suppliers. A definition is proposed to introduce the virus phenomenon. Virus authors come from a variety of communities. Motives and ideologies of authors are discussed, and examples of viruses are offered. Also mentioned is the growing number of viruses developed, isolated, and never distributed to the public at large, but kept within the antivirus research community. Virus examples are offered as well. Viruses are distributed not only through bulletin boards and shareware, but also from areas previously assumed to be safe, including the threat of receiving a virus through a standard in-house function, such as an in-house hardware maintenance shop. Three categories of viruses are presented: File Infecter viruses, Boot Sector Infecters, and the new category of Directory Entry Infecter virus. Also discussed are crossover viruses, that is, viruses which utilize a variety of techniques to ensure survival. An explanation of what is occurring within every stage of various viruses is given. Replication strategies common to all three types is noted, mainly the two different replication strategies of memory resident infecters and active selection infecters. A detailed definition, description and application of a stealth virus is presented. Detection strategies are discussed as each topic in this section is completed; a high level schemata of the operation of various virus detection programs ispresented. Since most eradication today is done using virus detection/eradication software, this paper attempts to reveal the techniques used by these packages.Included in the paper is the topic of manual eradication.

Pichnarczyk, K.

1992-07-01

308

PC viruses: How do they do that  

SciTech Connect

The topic of PC Viruses has been an issue for a number of years now. They've been reported in every major newspaper, tabloids, television and radio. People from all fields get viruses: government, private sector businesses, home computers, schools, computer software suppliers. A definition is proposed to introduce the virus phenomenon. Virus authors come from a variety of communities. Motives and ideologies of authors are discussed, and examples of viruses are offered. Also mentioned is the growing number of viruses developed, isolated, and never distributed to the public at large, but kept within the antivirus research community. Virus examples are offered as well. Viruses are distributed not only through bulletin boards and shareware, but also from areas previously assumed to be safe, including the threat of receiving a virus through a standard in-house function, such as an in-house hardware maintenance shop. Three categories of viruses are presented: File Infecter viruses, Boot Sector Infecters, and the new category of Directory Entry Infecter virus. Also discussed are crossover viruses, that is, viruses which utilize a variety of techniques to ensure survival. An explanation of what is occurring within every stage of various viruses is given. Replication strategies common to all three types is noted, mainly the two different replication strategies of memory resident infecters and active selection infecters. A detailed definition, description and application of a stealth virus is presented. Detection strategies are discussed as each topic in this section is completed; a high level schemata of the operation of various virus detection programs ispresented. Since most eradication today is done using virus detection/eradication software, this paper attempts to reveal the techniques used by these packages.Included in the paper is the topic of manual eradication.

Pichnarczyk, K.

1992-07-01

309

Scanning tunneling microscopy investigation of self-assembled CuPc/F16CuPc binary superstructures on graphite.  

PubMed

The self-assembly of the binary molecular system comprising copper(II) phthalocyanine (CuPc) and copper-hexadecafluoro-phthalocyanine (F(16)CuPc) on graphite has been investigated by in situ low-temperature scanning tunneling microscopy (LT-STM). The adsorption of this binary molecular system on graphite results in the formation of a well-ordered chessboardlike nanopattern. The in-plane molecular orientation of the guest CuPc molecules can be tuned by varying the coverage. At low coverage, the sparse CuPc molecules are randomly embedded in the host F(16)CuPc monolayer, possessing two different in-plane orientations; as the CuPc coverage increases, the in-plane molecular orientations of CuPc and F(16)CuPc become unidirectional and a highly ordered chessboardlike pattern forms. Molecular dynamic (MD) simulation results suggest that the selective and directional intermolecular hydrogen bonding determines the in-plane molecular orientation as well as the supramolecular packing arrangement. PMID:20175573

Huang, Yu Li; Li, Hui; Ma, Jing; Huang, Han; Chen, Wei; Wee, Andrew T S

2010-03-01

310

PC4CAST: A tool for DSN load forecasting and capacity planning  

NASA Technical Reports Server (NTRS)

Effectively planning the use and evolution of the Deep Space Network (DSN) is a complex problem involving many parameters. The tool that models many of these complexities, yet requires simple structured inputs and provides concise easy-to-understand metrics to aid in the planning process is discussed. The tool, PC4CAST, is used for both load forecasting (predicting how well planned that DSN resources meet expected demand) and as a decision support tool in the capacity-planning process (determining the relative benefits of capacity expansion options). It is now in use in the TDA Planning Office, has been used in numerous studies, and is also being used by the JPL Multimission Operations System Office (MOSO) as an integral part of Resource Allocation Team activities. Experience using the tool has helped to identify additional requirements that will further improve the planning process, which can be met by future PC4CAST versions.

Loyola, S. J.

1993-01-01

311

Propulsion stability codes for liquid propellant propulsion systems developed for use on a PC computer  

NASA Technical Reports Server (NTRS)

Research into component modeling and system synthesis leading to the analysis of the major types of propulsion system instabilities and the characterization of various components characteristics are presented. Last year, several programs designed to run on a PC were developed for Marshall Space Flight Center. These codes covered the low, intermediate, and high frequency modes of oscillation of a liquid rocket propulsion system. No graphics were built into these programs and only simple piping layouts were supported. This year's effort was to add run time graphics to the low and intermediate frequency codes, allow new types of piping elements (accumulators, pumps, and split pipes) in the low frequency code, and develop a new code for the PC to generate Nyquist plots.

Doane, George B., III; Armstrong, Wilbur C.

1991-01-01

312

Photodynamic Therapy with the Phthalocyanine Photosensitizer Pc 4  

PubMed Central

Photodynamic therapy (PDT) is emerging as a promising non-invasive treatment for cancers. PDT involves either local or systemic administration of a photosensitizing drug, which preferentially localizes within the tumor, followed by illumination of the involved organ with light, usually from a laser source. Here, we provide a selective overview of our experience with PDT at Case Western Reserve University, specifically with the silicon phthalocyanine photosensitizer Pc 4. We first review our in-vitro studies evaluating the mechanism of cell killing by Pc 4-PDT. Then we briefly describe our clinical experience in a Phase I trial of Pc 4-PDT and our preliminary translational studies evaluating the mechanisms behind tumor responses. Preclinical work identified (a) cardiolipin and the anti-apoptotic proteins Bcl-2 and Bcl-xL as targets of Pc 4-PDT, (b) the intrinsic pathway of apoptosis, with the key participation of caspase-3, as a central response of many human cancer cells to Pc 4-PDT, (c) signaling pathways that could modify apoptosis, and (d) a formulation by which Pc 4 could be applied topically to human skin and penetrate at least through the basal layer of the epidermis. Clinical-translational studies enabled us to develop an immunohistochemical assay for caspase-3 activation, using biopsies from patients treated with topical Pc 4 in a Phase I PDT trial for cutaneous T-cell lymphoma. Results suggest that this assay may be used as an early biomarker of clinical response. PMID:17397888

Miller, Janine D.; Baron, Elma D.; Scull, Heather; Hsia, Andrew; Berlin, Jeffrey C.; McCormick, Thomas; Colussi, Valdir; Kenney, Malcolm E.; Cooper, Kevin D.; Oleinick, Nancy L.

2007-01-01

313

ISTUM PC: industrial sector technology use model for the IBM-PC  

SciTech Connect

A project to improve and enhance the Industrial Sector Technology Use Model (ISTUM) was originated in the summer of 1983. The project had dix identifiable objectives: update the data base; improve run-time efficiency; revise the reference base case; conduct case studies; provide technical and promotional seminars; and organize a service bureau. This interim report describes which of these objectives have been met and which tasks remain to be completed. The most dramatic achievement has been in the area of run-time efficiency. From a model that required a large proportion of the total resources of a mainframe computer and a great deal of effort to operate, the current version of the model (ISTUM-PC) runs on an IBM Personal Computer. The reorganization required for the model to run on a PC has additional advantages: the modular programs are somewhat easier to understand and the data base is more accessible and easier to use. A simple description of the logic of the model is given in this report. To generate the necessary funds for completion of the model, a multiclient project is proposed. This project will extend the industry coverage to all the industrial sectors, including the construction of process flow models for chemicals and petroleum refining. The project will also calibrate this model to historical data and construct a base case and alternative scenarios. The model will be delivered to clients and training provided. 2 references, 4 figures, 3 tables.

Roop, J.M.; Kaplan, D.T.

1984-09-01

314

Drosophila melanogaster dHCF Interacts with both PcG and TrxG Epigenetic Regulators  

PubMed Central

Repression and activation of gene transcription involves multiprotein complexes that modify chromatin structure. The integration of these complexes at regulatory sites can be assisted by co-factors that link them to DNA-bound transcriptional regulators. In humans, one such co-factor is the herpes simplex virus host-cell factor 1 (HCF-1), which is implicated in both activation and repression of transcription. We show here that disruption of the gene encoding the Drosophila melanogaster homolog of HCF-1, dHCF, leads to a pleiotropic phenotype involving lethality, sterility, small size, apoptosis, and morphological defects. In Drosophila, repressed and activated transcriptional states of cell fate-determining genes are maintained throughout development by Polycomb Group (PcG) and Trithorax Group (TrxG) genes, respectively. dHCF mutant flies display morphological phenotypes typical of TrxG mutants and dHCF interacts genetically with both PcG and TrxG genes. Thus, dHCF inactivation enhances the mutant phenotypes of the Pc PcG as well as brm and mor TrxG genes, suggesting that dHCF possesses Enhancer of TrxG and PcG (ETP) properties. Additionally, dHCF interacts with the previously established ETP gene skd. These pleiotropic phenotypes are consistent with broad roles for dHCF in both activation and repression of transcription during fly development. PMID:22174740

Rodriguez-Jato, Sara; Busturia, Ana; Herr, Winship

2011-01-01

315

Oleanolic Acid Enhances the Beneficial Effects of Preconditioning on PC12 Cells  

PubMed Central

Preconditioning triggers endogenous protection against subsequent exposure to higher concentrations of a neurotoxin. In this study, we investigated whether exposure to oleanolic acid (OA) enhances the protective effects of preconditioning on PC12 cells exposed to 6-hydroxydopamine (6-OHDA). A concentration response curve was constructed using 6-OHDA (50, 150, 300, and 600??M). The experiment consisted of 6 groups: untreated, OA only, Group 1: cells treated with 6-OHDA (50??M) for 1 hour, Group 2: cells treated with 6-OHDA (150??M) for 1 hour, Group 3: cells treated with 6-OHDA (50??M) for 30 minutes followed 6 hours later by treatment with 6-OHDA (150??M) for 30 minutes, and Group 4: cells treated as in group 3 but also received OA immediately after the second 6-OHDA treatment. Cell viability and apoptotic ratio were assessed using the MTT and Annexin V staining tests, respectively. In preconditioned cells, we found that cell viability remained high following exposure to 6-OHDA (150??M). OA treatment enhanced the protective effects of preconditioning. Similarly, with the annexin V apoptosis test, preconditioning protected the cell and this was enhanced by OA. Therefore, preexposure of PC12 cells to low 6-OHDA concentration can protect against subsequent toxic insults of 6-OHDA and OA enhances this protection. PMID:25478286

Daniels, Willie M. U.; Mabandla, Musa V.

2014-01-01

316

A new PAT/QbD approach for the determination of blend homogeneity: combination of on-line NIRS analysis with PC Scores Distance Analysis (PC-SDA).  

PubMed

A novel and straightforward multivariate analytical tool for the qualitative determination of powder blend uniformity using on-line Near-Infrared Spectroscopy (NIRS) is presented. The approach combines current chemometric methods, e.g. spectral pre-processing and Principal Component Analysis (PCA), with (1) a new approach of data analysis to determine the end-point of the blending process, (2) building a design space (DS) for blend homogeneity and (3) developing a solid statistical rationale to stop blending according to Quality-by-Design (QbD) principles of FDA's Process Analytical Technology (PAT) initiative. The new approach comprises calculation of Euclidean distances between PCA scores in a multidimensional space and determination of Moving Block Standard Deviations (MBSDs) of successive Principal Component (PC) scores distances to estimate a time-window during blending where spectral variability decreases to a preset minimum. Hotelling's T(2) statistics is then used to monitor and report blend homogeneity. This technique is called "Principal Component Scores Distance Analysis" (PC-SDA). A Central Composite Design resulting in 10 batches mixed in a bin-blender (same composition, different blender fill level, different number of revolutions) was executed. NIR Chemical Imaging (NIR-CI) in combination with Symmetry Parameter Image Analysis (SPIA) was used to verify the NIRS analyzer response and assess homogeneity of all NIR-active components. PMID:21168484

Puchert, T; Holzhauer, C-V; Menezes, J C; Lochmann, D; Reich, G

2011-05-01

317

PC Farms for Offline Event Reconstruction at Fermilab  

SciTech Connect

Fermilab is investigating the use of PC`s for HEP computing. As a first step we have built a full offline environment under Linux on a set of Pentium (P5) and Pentium Pro (P6) machines (the ``PC Farm``). The Pythia simulation has been ported to run serially and in parallel (using CPS) on the PC Farm. Fermilab software products and CDF offline packages have also been ported to Linux. Run 1 CDF data has been analyzed on both Linux and SGI (Irix) with essentially identical results. The performance of the system is compared to results with commercial UNIX systems.

Beretvas, A.

1997-03-01

318

An International Strategy for Human Exploration of the Moon: The International Space Exploration Coordination Group (ISECG) Reference Architecture for Human Lunar Exploration  

NASA Technical Reports Server (NTRS)

The International Space Exploration Coordination Group (ISECG) was established in response to The Global Exploration Strategy: The Framework for Coordination developed by fourteen space agencies and released in May 2007. Several ISECG participating space agencies have been studying concepts for human exploration of the moon that allow individual and collective goals and objectives to be met. This 18 month study activity culminated with the development of the ISECG Reference Architecture for Human Lunar Exploration. The reference architecture is a series of elements delivered over time in a flexible and evolvable campaign. This paper will describe the reference architecture and how it will inform near-term and long-term programmatic planning within interested agencies. The reference architecture is intended to serve as a global point of departure conceptual architecture that enables individual agency investments in technology development and demonstration, International Space Station research and technology demonstration, terrestrial analog studies, and robotic precursor missions to contribute towards the eventual implementation of a human lunar exploration scenario which reflects the concepts and priorities established to date. It also serves to create opportunities for partnerships that will support evolution of this concept and its eventual realization. The ISECG Reference Architecture for Human Lunar Exploration (commonly referred to as the lunar gPoD) reflects the agency commitments to finding an effective balance between conducting important scientific investigations of and from the moon, as well as demonstrating and mastering the technologies and capabilities to send humans farther into the Solar System. The lunar gPoD begins with a robust robotic precursor phase that demonstrates technologies and capabilities considered important for the success of the campaign. Robotic missions will inform the human missions and buy down risks. Human exploration will start with a thorough scientific investigation of the polar region while allowing the ability to demonstrate and validate the systems needed to take humans on more ambitious lunar exploration excursions. The ISECG Reference Architecture for Human Lunar Exploration serves as a model for future cooperation and is documented in a summary report and a comprehensive document that also describes the collaborative international process that led to its development. ISECG plans to continue with architecture studies such as this to examine an open transportation architecture and other destinations, with expanded participation from ISECG agencies, as it works to inform international partnerships and advance the Global Exploration Strategy.

Laurini, Kathleen C.; Hufenbach, Bernhard; Junichiro, Kawaguchi; Piedboeuf, Jean-Claude; Schade, Britta; Lorenzoni, Andrea; Curtis, Jeremy; Hae-Dong, Kim

2010-01-01

319

Hands-on program of IBM-PC training at Los Alamos National Laboratory  

SciTech Connect

Since December 1983, the Laboratory has offered introductory courses of IBM-PC training. A comprehensive needs assessment was conducted and a nine-course module of classes was designed and implemented. Forty classes were completed in the one-year period. The target group includes the novice computer user in the scientific, management, administrative, and secretarial personnel groups. The development, needs assessment, course implementation and design, course evaluations, and future direction of computer training will be discussed. Lab-automation, robotics, design of the lab and office and the impact of computer on society will be discussed briefly.

Lier, R.H.

1985-01-01

320

Effects of Acupuncture at Neiguan (PC 6) of the Pericardial Meridian on Blood Pressure and Heart Rate Variability  

Microsoft Academic Search

The aims of this study were to investigate (i) if and when the blood pressure would rise or fall and (ii) the associated changes of human heart rate variability (HRV) by manual stimulation of the Neiguan (PC 6) acupuncture site. In this paper, two groups of six healthy male volunteers with ranges of ages 20- 56 and 20-55 and with

Shyang Chang; Meng-Ju Chiang; Shiun-Jeng Li; Yu-Tsung Lu; Chia-Mei Ma; Hsiu-Yao Cheng

2008-01-01

321

Near-equatorial Pi2 and Pc3 waves observed by CHAMP and on SAMBA/MAGDAS stations  

NASA Astrophysics Data System (ADS)

We have examined simultaneous ULF activity in the Pi2 and Pc3 bands at the near-equatorial magnetic stations in South America from SAMBA and MAGDAS arrays and low-orbiting CHAMP satellite during its passage over this meridional network. At the nighttime, both Pi2 and Pc3 waves in the upper ionosphere and on the ground are nearly of the same magnitude and in-phase. At the same time, the daytime Pc3 pulsations on the ground and in space are nearly out-of-phase. Comparison of observational results with the theoretical notions on the MHD wave interaction with the system ionosphere-atmosphere-ground suggests that nighttime low-latitude Pi2 and Pc3 wave signatures are produced by magnetospheric fast compressional mode. The daytime near-equatorial Pc3 waves still resist a quantative interpretation. These waves may be produced by a combination of two mechanisms: compressional mode leakage through the ionosphere, and by oscillatory ionospheric current spreading towards equatorial latitudes.

Cuturrufo, F.; Pilipenko, V.; Heilig, B.; Stepanova, M.; Lühr, H.; Vega, P.; Yoshikawa, A.

2015-02-01

322

Effect of carnosine and related compounds on proliferation of cultured rat pheochromocytoma PC-12 cells.  

PubMed

The study was undertaken to determine the mechanism of carnosine effect on cell proliferation. We studied the effect of carnosine and its derivatives on cell cycle progression in cultured rat pheochromocytoma cells (PC-12). It was found that 48-h incubation of PC-12 cells with carnosine in concentrations of 10-50 mM led to deceleration of cell proliferation, reduction of G0/G1 peak, and accumulation of S- and G2/M-phase cells. Methylation of the carnosine molecule by 1N-position of the imidazole ring potentiated its effect on cell proliferation. Acetylation of the carnosine molecule by free ?-amino group attenuated its effect. PMID:23330110

Rybakova, Yu S; Boldyrev, A A

2012-11-01

323

PC BEEPOP - A PERSONAL COMPUTER HONEY BEE POPULATION DYNAMICS MODEL  

EPA Science Inventory

PC BEEPOP is a computer model that simulates honey bee (Apis mellifera L.) colony population dynamics. he model consists of a system of interdependent elements, including colony condition, environmental variability, colony energetics, and contaminant exposure. t includes a mortal...

324

Single-event upset in advanced PowerPC microprocessors  

NASA Technical Reports Server (NTRS)

Proton and heavy-ion single-event upset susceptibility has been measured for the MotorolaPowerPC7400. The results show that this advanced device has low upset susceptibility, despite the scaling and design advances.

Irom, F.; Swift, G. M.; Farmanesh, F.; Millward, D. G.

2002-01-01

325

Software Reviews. PC Software for Artificial Intelligence Applications.  

ERIC Educational Resources Information Center

Contrasts artificial intelligence and conventional programming languages. Reviews Personal Consultant Plus, Smalltalk/V, and Nexpert Object, which are PC-based products inspired by problem-solving paradigms. Provides information on background and operation of each. (RT)

Epp, Helmut; And Others

1988-01-01

326

PC BEEPOP - AN ECTOXICOLOGICAL SIMULATION MODEL FOR HONEY BEE POPULATIONS  

EPA Science Inventory

PC BEEPOP is a computer model that simulates honey bee colony population dynamics. he model consists of a feedback system of interdependent elements, including colony condition, environmental variability, and contaminant exposures. t includes a mortality module (BEEKILL) and a ch...

327

Improving the flexibility of the desktop PC supply chain  

E-print Network

Dell Inc. is a company headquartered in Round Rock, TX founded by entrepreneur Michael Dell in 1984. In its 20+ years of history, Dell has revolutionized the PC industry by deploying the "Dell Direct" model--eliminating ...

Wu, Johnson (Johnson Chun Hsien)

2006-01-01

328

OCEAN-PC and a distributed network for ocean data  

NASA Technical Reports Server (NTRS)

The Intergovernmental Oceanographic Commission (IOC) wishes to develop an integrated software package for oceanographic data entry and access in developing countries. The software, called 'OCEAN-PC', would run on low cost PC microcomputers and would encourage and standardize: (1) entry of local ocean observations; (2) quality control of the local data; (3) merging local data with historical data; (4) improved display and analysis of the merged data; and (5) international data exchange. OCEAN-PC will link existing MS-DOS oceanographic programs and data sets with table-driven format conversions. Since many ocean data sets are now being distributed on optical discs (Compact Discs - Read Only Memory, CD-ROM, Mass et al. 1987), OCEAN-PC will emphasize access to CD-ROMs.

Mclain, Douglas R.

1992-01-01

329

Real time network simulation with PC-cluster  

Microsoft Academic Search

This paper presents a new architecture layout for a real-time power system simulator based on a distributed cluster of IBM PC-compatible desktop computers. A real-time network simulator based on a PC cluster can successfully cope with the size requirements of growing power systems and the computational demands of fast transient studies. A powerful product has been developed using off-the-shelf Pentium

Jorge Ariel Hollman; José Ramón Martí

2003-01-01

330

Wf/pc Cycle 3 Calibration: Rapid Internal Monitor  

NASA Astrophysics Data System (ADS)

This test is to take repeated internal flats to test for contamination buildup on the optical surfaces or the reappearance of QEH. Part 1: INTFLATS in F555W are obtained every 4 days in both WFC and PC to check for measles or daisies and to monitor scattered light. Part 2: Sequential INTFLATS in F439W with PC are obtained every 7 days to check for QEH.

MacKenty, John

1992-06-01

331

Wf/pc Cycle 2 Calibration: Rapid Internal Monitor  

NASA Astrophysics Data System (ADS)

This test is to take repeated internal flats to test for contamination buildup on the optical surfaces or the reappearance of QEH. Part 1: INTFLATS in F555W are obtained every 4 days in both WFC and PC to check for measles or daisies and to monitor scattered light. Part 2: Sequential INTFLATS in F439W with PC are obtained every 7 days to check for QEH.

MacKenty, John

1991-07-01

332

Wf/pc Cycle 1 Calibration: Rapid Internal Monitor  

NASA Astrophysics Data System (ADS)

This test is to take repeated internal flats to test for contamination buildup on the optical surfaces or the reappearance of QEH. Part 1: INTFLATS in F555W are obtained every 4 days in both WFC and PC to check for measles or daisies and to monitor scattered light. Part 2: Sequential INTFLATS in F439W with PC are obtained every 7 days to check for QEH.

MacKenty, John

1990-12-01

333

21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO2) monitor.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Cutaneous carbon dioxide (PcCO2) monitor. 868.2480...Devices § 868.2480 Cutaneous carbon dioxide (PcCO2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2 ) monitor is...

2011-04-01

334

21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO2) monitor.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Cutaneous carbon dioxide (PcCO2) monitor. 868.2480...Devices § 868.2480 Cutaneous carbon dioxide (PcCO2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2 ) monitor is...

2012-04-01

335

21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO 2) monitor.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 false Cutaneous carbon dioxide (PcCO 2) monitor. 868.2480...Devices § 868.2480 Cutaneous carbon dioxide (PcCO 2 ) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2 ) monitor is...

2014-04-01

336

21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO 2) monitor.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Cutaneous carbon dioxide (PcCO 2) monitor. 868.2480...Devices § 868.2480 Cutaneous carbon dioxide (PcCO 2 ) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2 ) monitor is...

2013-04-01

337

21 CFR 868.2480 - Cutaneous carbon dioxide (PcCO2) monitor.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Cutaneous carbon dioxide (PcCO2) monitor. 868.2480...Devices § 868.2480 Cutaneous carbon dioxide (PcCO2) monitor. (a) Identification. A cutaneous carbon dioxide (PcCO2 ) monitor is...

2010-04-01

338

Scabronine M, a novel inhibitor of NGF-induced neurite outgrowth from PC12 cells from the fungus Sarcodon scabrosus.  

PubMed

A novel cyathane diterpenoid, designated scabronine M (1), was isolated from the fruiting bodies of the mushroom Sarcodon scabrosus together with 10 known compounds. The structure of the new compound was elucidated on the basis of extensive spectroscopic analysis including 2D-NMR. Among these compounds, only scabronine M (1) significantly inhibited dose-dependently NGF-induced neurite outgrowth in PC12 cells without cytotoxicity, possibly through suppressing the phosphorylation of the receptor Trk A and the extracellular signal regulated kinases (ERK). This is the first report of novel neurite outgrowth-inhibiting activity in PC12 cells of this group of diterpenoids. PMID:22401866

Liu, Li; Shi, Xin-Wei; Zong, Shi-Chun; Tang, Jiang-Jiang; Gao, Jin-Ming

2012-04-01

339

WFPC2/PC Imagery of the Extended Circumstellar Disk of Beta Pictoris.  

NASA Astrophysics Data System (ADS)

We have observed the extensive circumstellar disk (Kuiper Belt) of beta Pictoris using the WFPC2/PC aboard the Hubble Space Telescope. We have used the pyramid of the WFPC2 to image separately the central star on a different CCD chip than that of the disk. This eliminated bleeding and other effects inherent in the CCDs, thereby leaving the PC chip containing the image of the disk relatively free from major contamination. By using the same observational setup and observing alpha Pic, a star of similar spectral type and magnitude to beta Pic, we could subtract out most of diffraction common to both stellar images. The final images clearly reveal the circumstellar disk of beta Pic extending the full width of the PC (34 arcseconds), sampling a disk radius >= 750 A.U. The disk shows clear evidence of asymmetric flaring at larger distances from the star. There is also a surprisingly sharp peak in the intensity distribution corresponding to the plane of the circumstellar disk. This is consistemt with an almost edge-on viewing angle for the disk. A summary of our recent HST observations of other possible beta Pic analogues are presented.

Bruhweiler, F.; Smith, B.; Miskey, C.; Silvis, J.; Disanti, M.; Schultz, A.; Hart, H.; Schneider, G.; Reinhard, K.

1997-12-01

340

Local extracellular acidification caused by Ca2+-dependent exocytosis in PC12 cells.  

PubMed

Exocytosis of acidic synaptic vesicles may produce local extracellular acidification, but this effect has not been measured directly and its magnitude may depend on the geometry and pH-buffering capacity of both the vesicles and the extracellular space. Here we have used SNARF dye immobilized by conjugation to dextran to measure the release of protons from PC12 cells. The PC12 cells were stimulated by exposure to depolarizing K(+)-rich solution and activation was verified by fluorescence measurement of intracellular Ca(2+) and the release kinetics of GFP-labeled vesicles. Confocal imaging of the pH-dependent fluorescence from the immobile extracellular SNARF dye showed transient acidification around the cell bodies and neurites of activated PC12 cells. The local acidification was abolished when extracellular solution was devoid of Ca(2+) or strong pH-buffering was imposed with 10mM of HEPES. We conclude that the release of secretory vesicles induces local rises in proton concentrations that are co-released from synaptic vesicles with the primary neurotransmitter, and propose that the co-released protons may modulate the signaling in confined micro-domains of synapses. PMID:18346783

Shuba, Yaroslav M; Dietrich, Craig Julius; Oermann, Eric; Cleemann, Lars; Morad, Martin

2008-08-01

341

OFFICESOFFICES GROUP STUDY  

E-print Network

, PUBLIC PRINTER PUBLIC COMPUTERS & SCANNER STUDY SPACE STUDY SPACE 5 REFERENCE BRO W SERY NEWBOOKS STUDY SOUTH GROUP STUDY SPACES MEDIA ROOM MICROFICHE/ MICROFILM ATHENA COMPUTERS & ADA STATION SCANNER, COPIER SPACE 6 SOUTH EAST WEST NORTH Q335-QA76.7 ATHENA COMPUTERS A-Q335 THESES TA1-TA499 QA805-TA1 QA76.7-QA

342

The role of P2X7 receptor in PC12 cells after exposure to oxygen-glucose deprivation.  

PubMed

Adenosine triphosphate (ATP) plays an important role in signal transmission via acting on P2X receptors. P2X7 receptor is involved in pathophysiological changes of ischemic diseases. The PC12 cell line is a popular model system to study sympathetic neuronal function. In this study, the effects of P2X7 on the viability or [Ca(2+)]i in PC12 cells after exposure to oxygen-glucose deprivation (OGD) were investigated. The results showed that the viability of PC12 cells was decreased under the condition of OGD. BzATP, a P2X7 agonist, decreased the viability, while P2X7 antagonist oxATP or P2X7 siRNA reversed the viability of PC12 cells under the condition of OGD. The expression levels of P2X7 mRNA and protein in PC12 cells were up-regulated under the condition of OGD or BzATP treatment. The expression levels of P2X7 mRNA and protein were significantly decreased in OGD PC12 cells, which were pretreated with oxATP or P2X7 siRNA. It was also found that oxATP or P2X7 siRNA effectively suppressed the increase of [Ca(2+)]i induced by OGD. P2X7 agonist ATP or BzATP enhanced the [Ca(2+)]i rise induced by OGD in PC12 cells. The [Ca(2+)]i peak induced by ATP or BzATP in OGD group was decreased by ERK inhibitor U0126. Therefore, P2X7 antagonists or P2X7 siRNA could depress the sympathetic neuronal damage induced by ischemia. PMID:24746144

Fan, Bo; Liu, Shuangmei; Xu, Changshui; Liu, Jun; Kong, Fanjun; Li, Guilin; Zhang, Chunping; Gao, Yun; Xu, Hong; Yu, Shicheng; Zheng, Chaoran; Peng, Lichao; Song, Miaomiao; Wu, Bing; Lv, Qiulan; Zou, Lifang; Ying, Mofeng; Zhang, Xi; Liang, Shangdong

2014-10-01

343

STRUCTURAL ANALYSIS ON PC BRIDGE GIRDERS DAMAGED BY SALT ATTACK CONSIDERATION WITH CORROSION OF PC STEEL BARS  

NASA Astrophysics Data System (ADS)

This paper aims to evaluate the structural performance of PC bridge girders damaged by chloride induced deterioration by using FE analysis code. In this analysis, the authors considered with corrosive mass loss and mechanical behavior for PC steel bars, which were obtained by investigation research of the target structure. The analysis has been conducted not only to eval uate the decreasing in structural performance, but also to verify infl uence on eccentrically-location of deteri orated girders. As a result, it is clarified that the structural perfor mance of the target bridge deck has gone down 24% after 32 years in service. Also the ductility tremendously decreased by excessive corrosion of PC steel bar, because the failure mode will change from concrete crashing to the PC bar rupturing. Fathermore, the structural performance will bring disadvantage by eccentri cally-location of deteriorated girders.

Kamiharako, Akihisa; Iwaki, Ichiro; Suzuki, Motoyuki

344

Role of Polycomb -group genes in sustaining activities of normal and malignant stem cells  

Microsoft Academic Search

Polycomb-group genes (PcG), identified by Drosophila genetics, are believed to maintain positional information by constituting a cellular memory system. Recently this system\\u000a has been proved to be supported by epigenetic transcription regulation. PcG products comprise two distinct complexes, PcG\\u000a complex 1 and 2. First PcG complex 2 silences chromatin and encodes a histone code by methylating histone H3 at lysine

Yoshihiro Takihara

2008-01-01

345

Morphine treatment selectively regulates expression of rat pituitary POMC and the prohormone convertases PC1/3 and PC2  

PubMed Central

The prohormone convertases, PC1/3 and PC2 are thought to be responsible for the activation of many prohormones through processing including the endogenous opioid peptides. We propose that maintenance of hormonal homeostasis can be achieved, in part, via alterations in levels of these enzymes that control the ratio of active hormone to prohormone. In order to test the hypothesis that exogenous opioids regulate the endogenous opioid system and the enzymes responsible for their biosynthesis, we studied the effect of short-term morphine or naltrexone treatment on pituitary PC1/3 and PC2 as well as on the level of pro-opiomelanocortin (POMC), the precursor gene for the biosynthesis of the endogenous opioid peptide, beta-endorphin. Using ribonuclease protection assays, we observed that morphine down-regulated and naltrexone up-regulated rat pituitary PC1/3 and PC2 mRNA. Immunofluorescence and Western blot analysis confirmed that the protein levels changed in parallel with the changes in mRNA levels and were accompanied by changes in the levels of phosphorylated cyclic-AMP response element binding protein. We propose that the alterations of the prohormone processing system may be a compensatory mechanism in response to an exogenous opioid ligand whereby the organism tries to restore its homeostatic hormonal milieu following exposure to the opioid, possibly by regulating the levels of multiple endogenous opioid peptides and other neuropeptides in concert. PMID:23891651

Anghel, Adrian; Paez Espinosa, Enma V.; Stuart, Ronald C.; Lutfy, Kabirullah; Nillni, Eduardo A.; Friedman, Theodore C.

2013-01-01

346

A metric space for Type Ia supernova spectra  

NASA Astrophysics Data System (ADS)

We develop a new framework for use in exploring Type Ia supernovae (SNe Ia) spectra. Combining principal component analysis (PCA) and partial least square (PLS) analysis we are able to establish correlations between the principal components (PCs) and spectroscopic/photometric SNe Ia features. The technique was applied to ˜120 SN and ˜800 spectra from the Nearby Supernova Factory. The ability of PCA to group together SNe Ia with similar spectral features, already explored in previous studies, is greatly enhanced by two important modifications: (1) the initial data matrix is built using derivatives of spectra over the wavelength, which increases the weight of weak lines and discards extinction, and (2) we extract time evolution information through the use of entire spectral sequences concatenated in each line of the input data matrix. These allow us to define a stable PC parameter space which can be used to characterize synthetic SN Ia spectra by means of real SN features. Using PLS, we demonstrate that the information from important previously known spectral indicators (namely the pseudo-equivalent width of Si II 5972 Å/Si II 6355 Å and the line velocity of S II 5640 Å/Si II 6355 Å) at a given epoch is contained within the PC space and can be determined through a linear combination of the most important PCs. We also show that the PC space encompasses photometric features like B/V magnitudes, B - V colours and SALT2 parameters c and x1. The observed colours and magnitudes, which are heavily affected by extinction, cannot be reconstructed using this technique alone. All the above-mentioned applications allowed us to construct a metric space for comparing synthetic SN Ia spectra with observations.

Sasdelli, Michele; Hillebrandt, W.; Aldering, G.; Antilogus, P.; Aragon, C.; Bailey, S.; Baltay, C.; Benitez-Herrera, S.; Bongard, S.; Buton, C.; Canto, A.; Cellier-Holzem, F.; Chen, J.; Childress, M.; Chotard, N.; Copin, Y.; Fakhouri, H. K.; Feindt, U.; Fink, M.; Fleury, M.; Fouchez, D.; Gangler, E.; Guy, J.; Ishida, E. E. O.; Kim, A. G.; Kowalski, M.; Kromer, M.; Lombardo, S.; Mazzali, P. A.; Nordin, J.; Pain, R.; Pécontal, E.; Pereira, R.; Perlmutter, S.; Rabinowitz, D.; Rigault, M.; Runge, K.; Saunders, C.; Scalzo, R.; Smadja, G.; Suzuki, N.; Tao, C.; Taubenberger, S.; Thomas, R. C.; Tilquin, A.; Weaver, B. A.

2015-02-01

347

PC/FRAM, Version 3.2 User Manual  

SciTech Connect

This manual describes the use of version 3.2 of the PC/FRAM plutonium isotopic analysis software developed in the Safeguards Science and Technology Group, NE-5, Nonproliferation and International Security Division Los Alamos National Laboratory. The software analyzes the gamma ray spectrum from plutonium-bearing items and determines the isotopic distribution of the plutonium 241Am content and concentration of other isotopes in the item. The software can also determine the isotopic distribution of uranium isotopes in items containing only uranium. The body of this manual descnies the generic version of the code. Special facility-specific enhancements, if they apply, will be described in the appendices. The information in this manual applies equally well to version 3.3, which has been licensed to ORTEC. The software can analyze data that is stored in a file on disk. It understands several storage formats including Canberra's S1OO format, ORTEC'S `chn' and `SPC' formats, and several ASCII text formats. The software can also control data acquisition using an MCA and then store the results in a file on disk for later analysis or analyze the spectrum directly after the acquisition. The software currently only supports the control of ORTEC MCB'S. Support for Canbema's Genie-2000 Spectroscopy Systems will be added in the future. Support for reading and writing CAM files will also be forthcoming. A versatile parameter fde database structure governs all facets of the data analysis. User editing of the parameter sets allows great flexibility in handling data with different isotopic distributions, interfering isotopes, and different acquisition parameters such as energy calibration, and detector type. This manual is intended for the system supervisor or the local user who is to be the resident expert. Excerpts from this manual may also be appropriate for the system operator who will routinely use the instrument.

Kelley, T.A.; Sampson, T.E.

1999-02-23

348

PC/FRAM, Version 3. 2 User Manual  

SciTech Connect

This manual describes the use of version 3.2 of the PC/FRAM plutonium isotopic analysis software developed in the Safeguards Science and Technology Group, NE-5, Nonproliferation and International Security Division Los Alamos National Laboratory. The software analyzes the gamma ray spectrum from plutonium-bearing items and determines the isotopic distribution of the plutonium 241Am content and concentration of other isotopes in the item. The software can also determine the isotopic distribution of uranium isotopes in items containing only uranium. The body of this manual descnies the generic version of the code. Special facility-specific enhancements, if they apply, will be described in the appendices. The information in this manual applies equally well to version 3.3, which has been licensed to ORTEC. The software can analyze data that is stored in a file on disk. It understands several storage formats including Canberra's S1OO format, ORTEC'S chn' and SPC' formats, and several ASCII text formats. The software can also control data acquisition using an MCA and then store the results in a file on disk for later analysis or analyze the spectrum directly after the acquisition. The software currently only supports the control of ORTEC MCB'S. Support for Canbema's Genie-2000 Spectroscopy Systems will be added in the future. Support for reading and writing CAM files will also be forthcoming. A versatile parameter fde database structure governs all facets of the data analysis. User editing of the parameter sets allows great flexibility in handling data with different isotopic distributions, interfering isotopes, and different acquisition parameters such as energy calibration, and detector type. This manual is intended for the system supervisor or the local user who is to be the resident expert. Excerpts from this manual may also be appropriate for the system operator who will routinely use the instrument.

Kelley, T.A.; Sampson, T.E.

1999-02-23

349

Real-space finite-difference approach for multi-body systems: path-integral renormalization group method and direct energy minimization method.  

PubMed

The path-integral renormalization group and direct energy minimization method of practical first-principles electronic structure calculations for multi-body systems within the framework of the real-space finite-difference scheme are introduced. These two methods can handle higher dimensional systems with consideration of the correlation effect. Furthermore, they can be easily extended to the multicomponent quantum systems which contain more than two kinds of quantum particles. The key to the present methods is employing linear combinations of nonorthogonal Slater determinants (SDs) as multi-body wavefunctions. As one of the noticeable results, the same accuracy as the variational Monte Carlo method is achieved with a few SDs. This enables us to study the entire ground state consisting of electrons and nuclei without the need to use the Born-Oppenheimer approximation. Recent activities on methodological developments aiming towards practical calculations such as the implementation of auxiliary field for Coulombic interaction, the treatment of the kinetic operator in imaginary-time evolutions, the time-saving double-grid technique for bare-Coulomb atomic potentials and the optimization scheme for minimizing the total-energy functional are also introduced. As test examples, the total energy of the hydrogen molecule, the atomic configuration of the methylene and the electronic structures of two-dimensional quantum dots are calculated, and the accuracy, availability and possibility of the present methods are demonstrated. PMID:21998159

Sasaki, Akira; Kojo, Masashi; Hirose, Kikuji; Goto, Hidekazu

2011-11-01

350

Polycomb Group Proteins Are Key Regulators of Keratinocyte Function  

Microsoft Academic Search

The Polycomb group (PcG) proteins are epigenetic suppressors of gene expression that function through modification of histones to change chromatin structure and modulate gene expression and cell behavior. Recent studies show that PcG proteins are expressed in epidermis, that their levels change during differentiation and in disease states, and that PcG expression is regulated by agents that influence cell proliferation

Richard L Eckert; Gautam Adhikary; Ellen A Rorke; Yap Ching Chew; Sivaprakasam Balasubramanian

2011-01-01

351

Histone trimethylation and the maintenance of transcriptional ONand OFF states by trxG and PcG proteins  

PubMed Central

Polycomb group (PcG) and trithorax group (trxG) proteins act as antagonistic regulators to maintain transcriptional OFF and ON states of HOX and other target genes. To study the molecular basis of PcG/trxG control, we analyzed the chromatin of the HOX gene Ultrabithorax (Ubx) in UbxOFFand UbxONcells purified from developing Drosophila. We find that PcG protein complexes PhoRC, PRC1, and PRC2 and the Trx protein are all constitutively bound to Polycomb response elements (PREs) in the OFF and ON state. In contrast, the trxG protein Ash1 is only bound in the ON state; not at PREs but downstream of the transcription start site. In the OFF state, we find extensive trimethylation at H3-K27, H3-K9, and H4-K20 across the entire Ubx gene; i.e., throughout the upstream control, promoter, and coding region. In the ON state, the upstream control region is also trimethylated at H3-K27, H3-K9, and H4-K20, but all three modifications are absent in the promoter and 5? coding region. Our analyses of mutants that lack the PcG histone methyltransferase (HMTase) E(z) or the trxG HMTase Ash1 provide strong evidence that differential histone lysine trimethylation at the promoter and in the coding region confers transcriptional ON and OFF states of Ubx. In particular, our results suggest that PRE-tethered PcG protein complexes act over long distances to generate Pc-repressed chromatin that is trimethylated at H3-K27, H3-K9, and H4-K20, but that the trxG HMTase Ash1 selectively prevents this trimethylation in the promoter and coding region in the ON state. PMID:16882982

Papp, Bernadett; Müller, Jürg

2006-01-01

352

Autophagy Regulates Colistin-Induced Apoptosis in PC-12 Cells.  

PubMed

Colistin is a cyclic cationic polypeptide antibiotic with activity against multidrug-resistant Gram-negative bacteria. Our recent study demonstrated that colistin induces apoptosis in primary chick cortex neurons and PC-12 cells. Although apoptosis and autophagy have different impacts on cell fate, there is a complex interaction between them. Autophagy plays an important role as a homeostasis regulator by removing excessive or unnecessary proteins and damaged organelles. The aim of the present study was to investigate the modulation of autophagy and apoptosis regulation in PC-12 cells in response to colistin treatment. PC-12 cells were exposed to colistin (125 to 250 ?g/ml), and autophagy was detected by visualization of monodansylcadaverine (MDC)-labeled vacuoles, LC3 (microtubule-associated protein 1 light chain 3) immunofluorescence microscopic examination, and Western blotting. Apoptosis was measured by flow cytometry, Hoechst 33258 staining, and Western blotting. Autophagosomes were observed after treatment with colistin for 12 h, and the levels of LC3-II gene expression were determined; observation and protein levels both indicated that colistin induced a high level of autophagy. Colistin treatment also led to apoptosis in PC-12 cells, and the level of caspase-3 expression increased over the 24-h period. Pretreatment of cells with 3-methyladenine (3-MA) increased colistin toxicity in PC-12 cells remarkably. However, rapamycin treatment significantly increased the expression levels of LC3-II and beclin 1 and decreased the rate of apoptosis of PC-12 cells. Our results demonstrate that colistin induced autophagy and apoptosis in PC-12 cells and that the latter was affected by the regulation of autophagy. It is very likely that autophagy plays a protective role in the reduction of colistin-induced cytotoxicity in neurons. PMID:25645826

Zhang, Ling; Zhao, Yonghao; Ding, Wenjian; Jiang, Guozheng; Lu, Ziyin; Li, Li; Wang, Jinli; Li, Jian; Li, Jichang

2015-04-01

353

Functional analysis of mouse Polycomb group genes  

Microsoft Academic Search

Two groups of genes, the Polycomb group (Pc-G) and trithorax group (trx-G), have been identified in Drosophila to provide a transcriptional memory mechanism. They ensure the maintenance of transcription patterns of key regulators such as the Hox genes and thereby the correct execution of developmental programmes. Recent data suggest that this memory mechanism is conserved in vertebrates and plants. Here

M. van Lohuizen

1998-01-01

354

Co?culture with bone marrow stromal cells protects PC12 neuronal cells from tumor necrosis factor???induced apoptosis by inhibiting the tumor necrosis factor receptor/caspase signaling pathway.  

PubMed

Bone marrow stromal cells (BMSCs), derived from the mesoderm, have been applied in the repair and reconstruction of injured tissues. The present study was conducted to explore the effects of BMSCs on cell viability of tumor necrosis factor?? (TNF??)?stimulated PC12 cells. PC12 cells were co?cultured with BMSCs under TNF?? treatment, with normal PC12 cells as controls. Results from an MTT assay indicated that BMSCs significantly increased cell growth and proliferation of TNF???treated PC12 cells (survival rates were 56.71 and 76.86% for the positive control (PC) and co?culture group, respectively). Furthermore, Annexin V/propidium iodide staining and flow cytometric analysis demonstrated that TNF?? increased PC12?cell apoptosis from 3.49 to 40.74% in the negative control and PC group, and the apoptotic rate was significantly reduced upon co?culture with BMSCs to 16.97%. In addition, data from reverse transcription?quantitative polymerase chain reaction and western blot analyses illustrated that TNF???induced upregulation in TNF receptor (TNFR)?1 (TNFR1) and caspase?8 expression in PC12 cells were partially reversed by co?culture with BMSCs. In conclusion, the present study suggested that BMSCs protect PC12 cells against stimulation with TNF??, which is partially mediated through the TNFR/caspase signaling pathway. The results of the present study also suggested a therapeutic use of BMSCs in clinical neurodegenerative diseases. PMID:25738414

Li, Li; Wang, Jing; Tang, Ling; Yu, Xin; Sui, Yi; Zhang, Chaodong

2015-07-01

355

Etifoxine promotes glial?derived neurotrophic factor?induced neurite outgrowth in PC12 cells.  

PubMed

Nerve regeneration and functional recovery are major issues following nerve tissue damage. Etifoxine is currently under investigation as a therapeutic strategy for promoting neuroprotection, accelerating axonal regeneration and modulating in?ammation. In the present study, a well?defined PC12 cell model was used to explore the underlying mechanism of etifoxine?stimulated neurite outgrowth. Etifoxine was found to promote glial?derived growth factor (GDNF)?induced neurite outgrowth in PC12 cells. Average axon length increased from 50.29±9.73 to 22.46±5.62 µm with the use of etifoxine. However, blockage of GDNF downstream signaling was found to lead to the loss of this phenomenon. The average axon length of the etifoxine group reduces to a normal level after the blockage of the GDNF family receptor ?1 (GFR?1) and receptor tyrosine kinase (RETS) receptors (27.46±3.59 vs. 22.46±5.62 µm and 25.31±3.68 µm vs. 22.46±5.62 µm, respectively, p>0.05). In addition, etifoxine markedly increased GDNF mRNA and protein expression (1.55? and 1.36-fold, respectively). However, blockage was not found to downregulate GDNF expression. The results of the current study demonstrated that etifoxine stimulated neurite outgrowth via GDNF, indicating that GDNF represents a key molecule in etifoxine?stimulated neurite outgrowth in PC12 cells. PMID:23670018

Zhou, Xiang; He, Xinhua; He, Bo; Zhu, Zhaowei; Zheng, Canbin; Xu, Jian; Jiang, Li; Gu, Liqiang; Zhu, Jiakai; Zhu, Qingtang; Liu, Xiaolin

2013-07-01

356

Functions of mammalian Polycomb group and trithorax group related genes  

Microsoft Academic Search

Genes of the Polycomb and trithorax groups (PcG and trxG) are part of a cellular memory system that maintains inactive and active states of homeotic gene expression in Drosophila. Recent genetic evidence indicates that several related loci in mammals are also involved in the regulation of Hox genes. Like their Drosophila counterparts, the vertebrate gene products are components of multiprotein

Alex Gould

1997-01-01

357

Binding of bovine T194A PrPC by PrPSc-specific antibodies  

PubMed Central

Transmissible spongiform encephalopathies (TSEs) are fatal neurodegenerative diseases that are based on the misfolding of a cellular prion protein (PrPC) into an infectious, pathological conformation (PrPSc). There is proof-of-principle evidence that a prion vaccine is possible but this is tempered with concerns of the potential dangers associated with induction of immune responses to a widely-expressed self-protein. By targeting epitopes that are specifically exposed upon protein misfolding, our group developed a vaccine that induces PrPSc-specific antibody responses. Here we consider the ability of this polyclonal antibody (SN6b) to bind to a mutant of PrPC associated with spontaneous prion disease. Polyclonal antibodies were selected to mimic the vaccination outcome and also explore all possible protein conformations of the recombinant bovine prion protein with mutation T194A [bPrP(T194A)]. This mutant is a homolog of the human T183A mutation of PrPC that is associated with early onset of familial dementia. With nanopore analysis, under non-denaturing conditions, we observed binding of the SN6b antibody to bPrP(T194A). This interaction was confirmed through ELISAs as well as immunoprecipitation of the recombinant and cellularly expressed forms of bPrP(T194A). This interaction did not promote formation of a protease resistant conformation of PrP in vitro. Collectively, these findings support the disease-specific approach for immunotherapy of prion diseases but also suggest that the concept of conformation-specific immunotherapy may be complicated in individuals who are genetically predisposed to PrPC misfolding. PMID:23787697

Madampage, Claudia A; Määttänen, Pekka; Marciniuk, Kristen; Brownlie, Robert; Andrievskaia, Olga; Potter, Andrew; Cashman, Neil R; Lee, Jeremy S; Napper, Scott

2013-01-01

358

Tablet PC as a mobil PACS terminal using wireless LAN  

NASA Astrophysics Data System (ADS)

A PACS mobile terminal has applications in ward round, emergency room and remote teleradiology consultation. Personal Digital Assistants (PDAs) have the highest mobility and are used for many medical applications. However, their roles are limited in the field of radiology due to small screen size. In this study, we built a wireless PACS terminal using a hand-held tablet-PC. A tablet PC (X-pilot, LEO systems, Taiwan) running the WinCE operating systems was used as our mobile PACS terminal. This device is equipped with 800×600 resolution 10.4 inch TFT monitor. The network connection between the tablet PC and the server was linked via wireless LAN (IEEE 802.11b).

Tsao, Bo-Shen; Ching, Yu-Tai; Lee, Wen-Jeng; Chen, Shyh-Jye; Chang, Chia-Hung; Chen, Chien-Jung; Yen, York; Lee, Yuan-Ten

2003-05-01

359

PC-1D installation manual and user's guide  

SciTech Connect

PC-1D is a software package for personal computers that uses finite-element analysis to solve the fully-coupled two-carrier semiconductor transport equations in one dimension. This program is particularly useful for analyzing the performance of optoelectronic devices such as solar cells, but can be applied to any bipolar device whose carrier flows are primarily one-dimensional. This User's Guide provides the information necessary to install PC-1D, define a problem for solution, solve the problem, and examine the results. Example problems are presented which illustrate these steps. The physical models and numerical methods utilized are presented in detail. This document supports version 3.1 of PC-1D, which incorporates faster numerical algorithms with better convergence properties than previous versions of the program. 51 refs., 17 figs., 5 tabs.

Basore, P.A.

1991-05-01

360

Laminin stimulates protein tyrosine dephosphorylation in PC12 cells.  

PubMed

Laminin stimulates neurite outgrowth in rat pheochromocytoma cells (PC12 cells). Here, we investigated laminin signal transduction mechanisms by adding the tyrosine kinase/phosphatase modulators, genistein, quercetin, aurin tricarboxylic acid (ATA), and vanadate to PC12 cells. At 10 microM both genistein and quercetin enhanced laminin-mediated neurite outgrowth by 1.7- and 2.3-fold, respectively, while at 10 microM, ATA inhibited laminin-mediated neurite outgrowth by 92%. Vanadate inhibited neurite outgrowth by 63% at 10 microM. Immunoblot analysis revealed four proteins of approximately 240, 22, 110, and 35 kDa, which were dephosphorylated on tyrosine residues in laminin-treated PC12 cells, but not in NIH 3T3 cells. These results demonstrate that laminin-mediated neurite outgrowth involves protein tyrosine dephosphorylation and suggests that this mechanism may have specificity to neuronal cells. PMID:10471391

Weeks, B S; Wilson, P J; Heffernan, C C; Gorra, V A; White, L E; Ahmad, A

1999-09-01

361

Pc1 Waves Observed by the Van Allen Probes and at Halley, Antarctica  

NASA Astrophysics Data System (ADS)

Waves in the Pc 1 frequency range (0.2 to 5 Hz) generated in Earth's magnetosphere serve as diagnostics of instabilities that are understood to thermalize energetic plasma populations, including ions in the ring current and possibly electrons in the radiation belts. We have compared observations of Pc1 waves detected by the EFW double probe electric field experiment and EMFISIS fluxgate magnetometer on the Van Allen Probes spacecraft and by a search coil magnetometer at Halley, Antarctica (L = 4.6). Transverse EMIC waves observed in space were observed at Halley during many intervals when the spacecraft were located within two hours of local time of Halley and within 1 L shell. Some of these conjunction events were observed as the spacecraft passed through regions of rapidly varying plasma density (i.e., the plasmapause or plume-like structures). Waves up to 4 Hz have occasionally been observed at Halley, but no conjunction events have yet been observed above 1.5 Hz. Purely compressional waves (with no evident transverse power) with frequencies above 2 Hz, and purely electrostatic waves (with no evident power in the magnetic field) with frequencies typically above 2 Hz, have also been observed in space, but not on the ground.

Posch, J. L.; Engebretson, M. J.; Roisen, N. D.; Perrin, J. B.; Breneman, A. W.; Kersten, K.; Wygant, J. R.; Kletzing, C.; Lessard, M.; Argall, M. R.; Smith, C. W.

2013-12-01

362

10 pc Scale Circumnuclear Molecular Gas Imaging of Nearby AGNs  

NASA Astrophysics Data System (ADS)

We present the images and kinematics of circumnuclear molecular gas from 100 pc scale down to 10 pc scale in nearby active galactic nuclei (AGNs) using the Submillimeter Array (SMA) and the Plateau de Bure Interferometer (PdBI). We have observed several nearby galaxies that host AGNs, such as the nearest radio galaxy Centaurus A (NGC 5128), the Seyfert 2 galaxy M51 (NGC 5194), the Seyfert 2 galaxy NGC 1068, the Seyfert 1 galaxy NGC 1097, and the Seyfert 2 / starburst composite galaxy NGC 4945, in CO lines to see whether the molecular gas distribution, kinematics, and physical conditions at 10 - 100 pc scale follows the AGN unified model or not. In 100 pc scale, most of the circumnuclear molecular gas shows smooth velocity gradient, suggesting a regular rotating feature, and also shows abnormal line ratios, suggesting the existence of active sources to make the circumnuclear molecular gas dense and/or warm conditions or abnormal chemical compositions. In 10 pc scale, on the other hand, the molecular gas kinematics shows various characteristics, some shows very disturbed kinematics such as a jet-entrained feature in the galaxies that have jets, but some still shows regular rotation feature in a galaxy that does not have obvious jets. These results indicate that the kinematics and physical/chemical conditions of the circumnuclear molecular gas at the scale less than 100 pc is highly affected by the AGN activities, and at this scale, there is no clear evidence of any unified feature seen in the circumnuclear molecular gas.

Matsushita, Satoki

2012-07-01

363

Online medical symbol recognition using a Tablet PC  

NASA Astrophysics Data System (ADS)

In this paper we describe a scheme to enhance the usability of a Tablet PC's handwriting recognition system by including medical symbols that are not a part of the Tablet PC's symbol library. The goal of this work is to make handwriting recognition more useful for medical professionals accustomed to using medical symbols in medical records. To demonstrate that this new symbol recognition module is robust and expandable, we report results on both a medical symbol set and an expanded symbol test set which includes selected mathematical symbols.

Kundu, Amlan; Hu, Qian; Boykin, Stanley; Clark, Cheryl; Fish, Randy; Jones, Stephen; Moore, Stephen

2011-01-01

364

Microwave coupling phenomenology of pc (printed-circuit) boards  

SciTech Connect

The final link in the High-Power Microwave (HPM) coupling chain is the distribution of energy on printed-circuit (pc) boards. This distribution is a critical part of the total problem, because the bottom line for damage or upset is what occurs at the component level. Like ports-of-entry (POE's), board coupling paths have their own transfer functions. Since most pc boards are not designed to operate at microwave frequencies, these transfer functions can be very complicated. In addition, active elements on the board are likely to make this part of the problem non-linear. 3 refs., 5 figs.

Bacon, L.D.; Riley, D.J.; Toth, R.P.

1989-01-01

365

OAST Space Theme Workshop. Volume 3: Working group summary. 6: Power (P-2). A. Statement. B. Technology needs (form 1). C. Priority assessment (form 2)  

NASA Technical Reports Server (NTRS)

Power requirements for the multipurpose space power platform, for space industrialization, SETI, the solar system exploration facility, and for global services are assessed for various launch dates. Priorities and initiatives for the development of elements of space power systems are described for systems using light power input (solar energy source) or thermal power input, (solar, chemical, nuclear, radioisotopes, reactors). Systems for power conversion, power processing, distribution and control are likewise examined.

1976-01-01

366

Processing and intracellular localization of rice stripe virus Pc2 protein in insect cells  

SciTech Connect

Rice stripe virus (RSV) belongs to the genus Tenuivirus and its genome consists of four single-stranded RNAs encoding seven proteins. Here, we have analyzed the processing and membrane association of Pc2 encoded by vcRNA2 in insect cells. The enhanced green fluorescent protein (eGFP) was fused to the Pc2 and used for the detection of Pc2 fusion proteins. The results showed that Pc2 was cleaved to produce two proteins named Pc2-N and Pc2-C. When expressed alone, either Pc2-N or Pc2-C could transport to the Endoplasmic reticulum (ER) membranes independently. Further mutagenesis studies revealed that Pc2 contained three ER-targeting domains. The results led us to propose a model for the topology of the Pc2 in which an internal signal peptide immediately followed a cleavage site, and two transmembrane regions are contained.

Zhao, Shuling; Zhang, Gaozhan; Dai, Xuejuan; Hou, Yanling; Li, Min [College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009 (China)] [College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009 (China); Liang, Jiansheng, E-mail: jsliang@yzu.edu.cn [College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009 (China)] [College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009 (China); Liang, Changyong, E-mail: cyliang@yzu.edu.cn [College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009 (China)] [College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009 (China)

2012-08-01

367

Polycomb group protein bodybuilding: working out the routines.  

PubMed

Polycomb group (PcG) proteins regulate gene expression by modifying chemical and structural properties of chromatin. Isono et al. (2013) now report in Developmental Cell a polymerization-dependent mechanism used by PcG proteins to form higher-order chromatin structures, referred to as Polycomb bodies, and demonstrate its necessity for gene silencing. PMID:24091008

Sievers, Cem; Paro, Renato

2013-09-30

368

Architectural and Functional Diversity of Polycomb Group Response Elements in Drosophila  

PubMed Central

Polycomb group response elements (PREs) play an essential role in gene regulation by the Polycomb group (PcG) repressor proteins in Drosophila. PREs are required for the recruitment and maintenance of repression by the PcG proteins. PREs are made up of binding sites for multiple DNA-binding proteins, but it is still unclear what combination(s) of binding sites is required for PRE activity. Here we compare the binding sites and activities of two closely linked yet separable PREs of the Drosophila engrailed (en) gene, PRE1 and PRE2. Both PRE1 and PRE2 contain binding sites for multiple PRE–DNA-binding proteins, but the number, arrangement, and spacing of the sites differs between the two PREs. These differences have functional consequences. Both PRE1 and PRE2 mediate pairing-sensitive silencing of mini-white, a functional assay for PcG repression; however, PRE1 requires two binding sites for Pleiohomeotic (Pho), whereas PRE2 requires only one Pho-binding site for this activity. Furthermore, for full pairing-sensitive silencing activity, PRE1 requires an AT-rich region not found in PRE2. These two PREs behave differently in a PRE embryonic and larval reporter construct inserted at an identical location in the genome. Our data illustrate the diversity of architecture and function of PREs. PMID:23934890

Brown, J. Lesley; Kassis, Judith A.

2013-01-01

369

Trithorax group proteins: switching genes on and keeping them active  

Microsoft Academic Search

Cellular memory is provided by two counteracting groups of chromatin proteins termed Trithorax group (TrxG) and Polycomb group (PcG) proteins. TrxG proteins activate transcription and are perhaps best known because of the involvement of the TrxG protein MLL in leukaemia. However, in terms of molecular analysis, they have lived in the shadow of their more famous counterparts, the PcG proteins.

Bernd Schuettengruber; Anne-Marie Martinez; Nicola Iovino; Giacomo Cavalli

2011-01-01

370

Transgressive loop group extensions  

E-print Network

A central extension of the loop group of a Lie group is called transgressive, if it corresponds under transgression to a degree four class in the cohomology of the classifying space of the Lie group. Transgressive loop group extensions are those that can be explored by finite-dimensional, higher-categorical geometry over the Lie group. We show how transgressive central extensions can be characterized in a loop-group theoretical way, in terms of loop fusion and thin homotopy equivariance.

Konrad Waldorf

2015-02-17

371

Path-consistency: When space misses time  

SciTech Connect

Within the framework of constraint programming, particulary concerning the Constraint Satisfaction Problems (CSPs), the techniques of preprocessing based on filtering algorithms were shown to be very important for the search phase. In particular, two filtering methods have been studied, these methods exploit two properties of local consistency: arc- and path-consistency. Concerning the arc-consistency methods, there is a linear time algorithm (in the size of the problem) which is efficient in practice. But the limitations of the arc-consistency algorithms requires often filtering methods with higher order like path-consistency filterings. The best path-consistency algorithm proposed is PC-6, a natural generalization of AC-6 to path-consistency. Its time complexity is O(n{sup 3}d{sup 4}) and its space complexity is O(n{sup 3}d{sup 4}), where n is the number of variables and d is the size of domains. We have remarked that PC-6, though it is widely better than PC-4, was not very efficient in practice, specially for those classes of problems that require an important space to be run. Therefore, we propose here a new path-consistency algorithm called PC-7, its space complexity is O(n{sup 3}d{sup 4}) but its time complexity is O(n{sup 3}d{sup 4}) i.e. worse than that of PC-6. However, the simplicity of PC-7 as well as the data structures used for its implementation offer really a higher performance than PC-6. Furthermore, it turns out that when the size of domains is a constant of the problems, the time complexity of PC-7 becomes. like PC-6, optimal i.e. O(n{sup 3}).

Chmeiss, A.; Jegou, P. [Universite de Provence, Marseille (France)

1996-12-31

372

Characterization of the Pneumocystis carinii histone acetyltransferase chaperone proteins PcAsf1 and PcVps75.  

PubMed

Rtt109 is a lysine acetyltransferase that acetylates histone H3 at lysine 56 (H3K56) in fungi. This acetylation event is important for proper DNA replication and repair to occur. Efficient Rtt109 acetyltransferase activity also requires a histone chaperone, vacuolar protein sorting 75 (Vps75), as well as the major chaperone of the H3-H4 dimer, anti-silencing factor 1 (Asf1). Little is known about the role of these proteins in the opportunistic fungal pathogen Pneumocystis carinii. To investigate the functions of Asf1 and Vps75 in Pneumocystis carinii, we cloned and characterized both of these genes. Here, we demonstrate that both genes, P. carinii asf1 (Pcasf1) and Pcvps75, function in a fashion analogous to their Saccharomyces cerevisiae counterparts. We demonstrate that both P. carinii Asf1 (PcAsf1) and PcVps75 can bind histones. Furthermore, when Pcasf1 is expressed heterologously in S. cerevisiae asf1? cells, PcAsf1 can restore full H3 lysine acetylation. We further demonstrated that the Pcasf1 cDNA expressed in asf1? S. cerevisiae cells can restore growth to wild-type levels in the presence of genotoxic agents that block DNA replication. Lastly, we observed that purified PcAsf1 and PcVps75 proteins enhance the ability of PcRtt109 to acetylate histone H3-H4 tetramers. Together, our results indicate that the functions of the Rtt109-Asf1-Vps75 complex in the acetylation of histone H3 lysine 56 and in DNA damage response are present in P. carinii DNA and cell cycle progression. PMID:23569117

Pupaibool, Jakrapun; Kottom, Theodore J; Bouchonville, Kelly; Limper, Andrew H

2013-06-01

373

Characterization of the Pneumocystis carinii Histone Acetyltransferase Chaperone Proteins PcAsf1 and PcVps75  

PubMed Central

Rtt109 is a lysine acetyltransferase that acetylates histone H3 at lysine 56 (H3K56) in fungi. This acetylation event is important for proper DNA replication and repair to occur. Efficient Rtt109 acetyltransferase activity also requires a histone chaperone, vacuolar protein sorting 75 (Vps75), as well as the major chaperone of the H3-H4 dimer, anti-silencing factor 1 (Asf1). Little is known about the role of these proteins in the opportunistic fungal pathogen Pneumocystis carinii. To investigate the functions of Asf1 and Vps75 in Pneumocystis carinii, we cloned and characterized both of these genes. Here, we demonstrate that both genes, P. carinii asf1 (Pcasf1) and Pcvps75, function in a fashion analogous to their Saccharomyces cerevisiae counterparts. We demonstrate that both P. carinii Asf1 (PcAsf1) and PcVps75 can bind histones. Furthermore, when Pcasf1 is expressed heterologously in S. cerevisiae asf1? cells, PcAsf1 can restore full H3 lysine acetylation. We further demonstrated that the Pcasf1 cDNA expressed in asf1? S. cerevisiae cells can restore growth to wild-type levels in the presence of genotoxic agents that block DNA replication. Lastly, we observed that purified PcAsf1 and PcVps75 proteins enhance the ability of PcRtt109 to acetylate histone H3-H4 tetramers. Together, our results indicate that the functions of the Rtt109-Asf1-Vps75 complex in the acetylation of histone H3 lysine 56 and in DNA damage response are present in P. carinii DNA and cell cycle progression. PMID:23569117

Pupaibool, Jakrapun; Kottom, Theodore J.; Bouchonville, Kelly

2013-01-01

374

PC Board Layout and Electronic Drafting with CAD. Teacher Edition.  

ERIC Educational Resources Information Center

This teacher's guide contains 11 units of instruction for a course on computer electronics and computer-assisted drafting (CAD) using a personal computer (PC). The course covers the following topics: introduction to electronic drafting with CAD; CAD system and software; basic electronic theory; component identification; basic integrated circuit…

Bryson, Jimmy

375

Visual search and the N2pc in children.  

PubMed

While there is growing understanding of visual selective attention in children, some aspects such as selection in the presence of distractors are not well understood. Adult studies suggest that when presented with a visual search task, an enhanced negativity is seen beginning around 200 ms (the N2pc) that reflects selection of a target item among distractors. However, it is not known if similar selective attention-related activity is seen in children during visual search. This study was designed to investigate the presence of the N2pc in children. Nineteen children (ages 9-12 years) and 21 adults (ages 18-22 years) completed a visual search task in which they were asked to attend to a fixation surrounded by both a target and a distractor stimulus. Three types of displays were analyzed at parietal electrodes P7 and P8; lateral target/lateral distractor, lateral target/midline distractor, and midline target/lateral distractor. Both adults and children showed a significant increased negativity contralateral compared to ipsilateral to the target (reflected in the N2pc) in both displays with a lateral target while no such effect was seen in displays with a midline target. This suggests that children also utilized additional resources to select a target item when distractors are present. These findings demonstrate that the N2pc can be used as a marker of attentional object selection in children. PMID:25678274

Couperus, Jane W; Quirk, Colin

2015-04-01

376

Performance of Parallel Logic Event Simulation on PC-Cluster  

Microsoft Academic Search

PC-cluster is becoming more and more popular in many scientific and engineering applications, but not in electronic design areas. One of the reasons that parallel simulations have not been popularized is due to the high cost of frequent communications of small messages. Several simulation techniques have been aggressively studied and developed in the past ten years. These studies mostly focused

Thuy T. Le; Jalel Rejeb

2004-01-01

377

PC-CUBE: A personal computer based hypercube  

NASA Technical Reports Server (NTRS)

PC-CUBE is an ensemble of IBM PCs or close compatibles connected in the hypercube topology with ordinary computer cables. Communication occurs at the rate of 115.2 K-band via the RS-232 serial links. Available for PC-CUBE is the Crystalline Operating System III (CrOS III), Mercury Operating System, CUBIX and PLOTIX which are parallel I/O and graphics libraries. A CrOS performance monitor was developed to facilitate the measurement of communication and computation time of a program and their effects on performance. Also available are CXLISP, a parallel version of the XLISP interpreter; GRAFIX, some graphics routines for the EGA and CGA; and a general execution profiler for determining execution time spent by program subroutines. PC-CUBE provides a programming environment similar to all hypercube systems running CrOS III, Mercury and CUBIX. In addition, every node (personal computer) has its own graphics display monitor and storage devices. These allow data to be displayed or stored at every processor, which has much instructional value and enables easier debugging of applications. Some application programs which are taken from the book Solving Problems on Concurrent Processors (Fox 88) were implemented with graphics enhancement on PC-CUBE. The applications range from solving the Mandelbrot set, Laplace equation, wave equation, long range force interaction, to WaTor, an ecological simulation.

Ho, Alex; Fox, Geoffrey; Walker, David; Snyder, Scott; Chang, Douglas; Chen, Stanley; Breaden, Matt; Cole, Terry

1988-01-01

378

PC vs. Mac--Which Way Should You Go?  

ERIC Educational Resources Information Center

Outlines the factors in hardware, software, and administration to consider in developing specifications for choosing a computer operating system. Compares Microsoft Windows 95/NT that runs on PC/Intel-based systems and System 7.5 that runs on the Apple-based systems. Lists reasons why the Microsoft platform clearly stands above the Apple platform.…

Wodarz, Nan

1997-01-01

379

An Apple for Your IBM PC--The Quadlink Board.  

ERIC Educational Resources Information Center

Describes nature and installation of the QUADLINK board which allows Apple software to be run on IBM PC microcomputers. Although programs tested ran without problems, users should test their own programs since there are some copy protection schemes that can baffle the board. (JN)

Owen, G. Scott

1984-01-01

380

A NAND Flash PC Platform Read Write Cache  

Microsoft Academic Search

The traditional and ideal use of NAND flash has been primarily for the storage of digital images, music files, or data files in various memory cards types or USB keys. In this paper, a new non-volatile memory layer hierarchy is introduced into the PC computing platform as a NAND flash read write cache interfacing to the PCI express bus. The

H. Pon; K. Rao

2007-01-01

381

Falling PC Solitaire Cards: An Open-Inquiry Approach  

ERIC Educational Resources Information Center

Many of us have played the PC Solitaire game that comes as standard software in many computers. Although I am not a great player, occasionally I win a game or two. The game celebrates my accomplishment by pushing the cards forward, one at a time, falling gracefully in what appears to look like a parabolic path in a drag-free environment. One day,…

Gonzalez-Espada, Wilson J.

2012-01-01

382

Photon-counting airborne laser swath mapping (PC-ALSM)  

NASA Astrophysics Data System (ADS)

University of Florida (UF) researchers are developing an airborne laser swath mapping (ALSM) unit based on a paradigm referred to as photon counting ALSM, or PC-ALSM. In the PC-ALSM approach relatively low energy (few micro-joule) laser pulses are used to illuminate a surface 'patch' of terrain a few meters in extent. Reflected photons are imaged onto a multi-channel photomultiplier tube, to achieve high resolution (few decimeter) contiguous coverage of the terrain. A multi-channel multi-stop timing unit records both noise and signal events within a range gated window, and the noise events are filtered out of the data during post flight processing. A first generation PC-ALSM sensor, the Coastal Area Tactical-mapping System (CATS), is being developed with funding from the Office of Naval Research (ONR). The CATS sensor will be tested and operated from the UF Cessna 337 aircraft, which is equipped with a commercial ALSM unit. However, the ultimate goal of the UF research is to verify that PC-ALSM offers the possibility of developing a high resolution airborne laser mapping unit small and light enough, and with sufficient energy efficiency, to operate from a UAV.

Carter, William E.; Shrestha, Ramesh L.; Slatton, Kenneth C.

2004-12-01

383

Deciding when It's Time to Buy a New PC  

ERIC Educational Resources Information Center

How to best decide when it's time to replace your PC, whether at home or at work, is always tricky. Spending on computers can make you more productive, but it's money you otherwise cannot spend, invest or save, and faster systems always await you in the future. What is clear is that the computer industry really wants you to buy, and the computer…

Goldsborough, Reid

2004-01-01

384

Personalized adaptive strategies in human-PC learning game  

Microsoft Academic Search

This paper describes the effect of introducing personalized adaptive strategies into a human-PC interactive learning game. In this game, a computer can execute adaptive strategies according to a user's performance level. Through simulations with subjects, we verified that we could control the user's score by changing the computer's ability. It means that we can identify a user's ability by referring

M. Morizane; Y. Nakano; K. Shimohara; I. Tanev

2009-01-01

385

A haptic device for PC video game application  

Microsoft Academic Search

A haptic device is developed for PC video games. The proposed mechanism is designed to avoid a coupling problem in two-degree of freedom translational movement at the edges caused by the structural constraints using a motor whose body is rotating about a pivot according to the joystick motion. The workspace of the proposed mechanism is analyzed. The spring and damping

Byunghoon Bae; Taeoh Koo

2004-01-01

386

THE EFFECT OF FIBROBLAST GROWTH FACTOR ON PC12 CELLS  

Microsoft Academic Search

PC12 cells, which differentiate morphologically and biochemically into sympathetic neuron-like cells when treated with nerve growth factor, also respond to fibroblast growth factor. Some of the changes induced by fibroblast growth factor are similar to those seen after nerve growth factor treatment. Specifically, pituitary fibroblast growth factor causes the formation of processes initially comparable to those produced by nerve growth

AKIFUMI TOGARI; GENEVA DICKENS; HIROSHI KUZUYA; GORDON GUROFF

1985-01-01

387

Augmenting Network Interfaces to Reduce PC Energy Usage  

Microsoft Academic Search

Reducing the energy consumption of PCs is becom- ing increasingly important with rising energy costs and environmental concerns. Sleep states such as S3 (sus- pend to RAM) save energy but prevent the PC from re- sponding to network traffic, for example remote desktop logins, file transfer requests, or content distribution pro - tocols such as bittorrent. We conducted a background

Yuvraj Agarwal; Steve J. Hodges; James Scott; Ranveer Chandra; Paramvir Bahl; Rajesh Gupta

388

vAMT PC AMT WS-Management SOAP  

E-print Network

-Management SOAP vAMT WS-Management vAMT Common Information Model CIM AMT SOAP AMT Web AMT vAMT PC VM AMT vAMT 1 WS-Management CIM CIM vAMT CIM VM VM SOAP Web CIM VM CIMPLE [1] CIM MOF CIM vAMT CIM Axis2 [2] Web 1: vAMT WSDL Web

Kourai, Kenichi

389

Teaching Electric Circuits Using Tablet PC and Centra  

NSDL National Science Digital Library

An increasing trend for lecture-based courses is for instructors to convert their lecture notes to PowerPoint based presentation. While there are many advantages to electronic projection, a large drawback is the loss of interactivity. The use of a Tablet PC by the instructor promises to overcome this difficulty. The Tablet PC, combined with appropriate software, enables the instructor to write and draw using digital ink. This work describes our experience in using Tablet PC in conjunction with Centra to teach Electric Circuits. A typical lecture consists of preparing the agenda and lecture notes using PowerPoint. The PowerPoint presentation includes explanations of the covered topics and only statements of the problems that are going to be discussed during the lecture. When an example is reached, the Journal Viewer of the Tablet PC would be used to show step-by-step solution of the problem. The Journal Viewer file will include the schematics of the example problem. Electronics Workbench is used for schematic drawings. A brief discussion of this approach and the advantages and disadvantages of such a scheme will be presented.

Azemi, Asad

390

Mapping of the oat crown rust resistance gene Pc91  

Microsoft Academic Search

Crown rust is an important disease of oat caused by Puccinia coronata Corda f. sp. avenae Eriks. Crown rust is efficiently and effectively managed through the development of resistant oat varieties. Pc91 is a seedling crown rust resistance gene that is highly effective against the current P. coronata population in North America. The primary objective of this study was to

C. A. McCartney; R. G. Stonehouse; B. G. Rossnagel; P. E. Eckstein; G. J. Scoles; T. Zatorski; A. D. Beattie; J. Chong

2011-01-01

391

Mathematics Programming on the Apple II and IBM PC.  

ERIC Educational Resources Information Center

Details the features of BASIC used in mathematics programming and provides the information needed to translate between the Apple II and IBM PC computers. Discusses inputing a user-defined function, setting scroll windows, displaying subscripts and exponents, variable names, mathematical characters and special symbols. (TW)

Myers, Roy E.; Schneider, David I.

1987-01-01

392

Differences in the autocatalytic cleavage of pro-PC2 and pro-PC3 can be attributed to sequences within the propeptide and Asp310 of pro-PC2.  

PubMed Central

PC2 and PC3 are subtilisin-like proteases involved in the maturation of prohormones and proneuropeptides within neuroendocrine cells. They are synthesized as zymogens that undergo autocatalytic maturation within the secretory pathway. Maturation of pro-PC2 is slow (t12 >8 h), exhibits a pH optimum of 5.5 and is dependent on calcium (K0.5 2 mM), while pro-PC3 maturation is relatively rapid (t12 15 min), exhibits a neutral pH optimum and is not calcium dependent. These differences in the rates and optimal conditions for activation of the proteases may contribute to the diversity of products generated by these proteases in different cell types. Although highly similar, there are two major differences between pro-PC2 and pro-PC3: the presence of an aspartate at position 310 in pro-PC2 compared with asparagine at the equivalent position in pro-PC3 (and all other members of the subtilisin family), and the N-terminal propeptides, which exhibit low sequence identity (30%). With a view to establishing the structural features that might be responsible for these differences in the maturation of pro-PC2 and pro-PC3, Asp310 in pro-PC2 was mutated to Asn, and Asn309 in pro-PC3 was mutated to Asp. Chimaeric proteins were also made consisting of the pro-region of PC2 fused to the mature portion of PC3 and the pro-region of PC3 fused to the mature region of PC2. The wild-type and mutant DNA constructs were then transcribed and translated in an in vitro system capable of supporting maturation of pro-PC2 and pro-PC3. The results demonstrated that Asp310 of pro-PC2 is responsible for the acidic pH optimum for maturation. Thus changing Asp310 to Asn shifted the pH optimum for maturation to pH 7.0. However, changing Asn309 of pro-PC3 to Asp had no effect on the optimum pH for maturation of pro-PC3. A chimaeric construct containing the propeptide of pro-PC2 attached to PC3 shifted the pH optimum for maturation from pH 7.0 to 6.0 and slowed down the rate of maturation (t12 >8 h). When attached to PC2, the pro-region of pro-PC3 had no effect on the optimum pH for maturation (pH 5.5-6.0), but it did accelerate the rate of maturation (t12 2 h). These results demonstrate that Asp310 and the pro-region of pro-PC2 contribute to the acidic pH optimum and low rate of maturation of this zymogen relative to its closely related homologue PC3. PMID:9729458

Scougall, K; Taylor, N A; Jermany, J L; Docherty, K; Shennan, K I

1998-01-01

393

IUCN Otter Spec. Group Bull. 20(1) 2003 IUCN OTTER SPECIALIST GROUP BULLETIN  

E-print Network

IUCN Otter Spec. Group Bull. 20(1) 2003 IUCN OTTER SPECIALIST GROUP BULLETIN VOLUME 20 ISSUE 1 PAGES 6 - 18 Citation: Alarcon, G.G. and Simões-Lopes, P.C.. (2003) Preserved Versus Degraded Coastal, Southern Brazil . IUCN Otter Spec. Group Bull. 20(1): 6 - 18 PRESERVED VERSUS DEGRADED COASTAL ENVIRONMENTS

Simões-Lopes, Paulo César

394

IUCN Otter Spec. Group Bull. 21(1) 2004 IUCN OTTER SPECIALIST GROUP BULLETIN  

E-print Network

IUCN Otter Spec. Group Bull. 21(1) 2004 IUCN OTTER SPECIALIST GROUP BULLETIN VOLUME 21 ISSUE 1 PAGES 24 - 30 Citation: Alarcon, G.G. and Simões-Lopes, P.C. (2004) The Neotropical Otter Lontra Longicaudis Feeding Habits In A Marine Coastal Area, Southern Brazil . IUCN Otter Spec. Group Bull. 21(1): 24

Simões-Lopes, Paulo César

395

OFFICESOFFICES GROUP STUDY  

E-print Network

SOUTH GROUP STUDY SPACES MEDIA ROOM MICROFICHE/ MICROFILM CURRENT JOURNALS REFERENCE COLLECTION & GOVERNMENT DOCUMENTS ATHENA COMPUTERS & ADA STATION SCANNER, COPIER, PUBLIC PRINTER PUBLIC COMPUTERS & SCANNER STUDY SPACE STUDY SPACE 5 DVD/VHS BRO W SERY NEWBOOKS 6 SOUTH EAST WEST Q335-QA76.7 ATHENA

396

Space Resources and Space Settlements  

NASA Technical Reports Server (NTRS)

The technical papers from the five tasks groups that took part in the 1977 Ames Summer Study on Space Settlements and Industrialization Using Nonterrestrial Materials are presented. The papers are presented under the following general topics: (1) research needs for regenerative life-support systems; (2) habitat design; (3) dynamics and design of electromagnetic mass drivers; (4) asteroids as resources for space manufacturing; and (5) processing of nonterrestrial materials.

Billingham, J. (editor); Gilbreath, W. P. (editor); Oleary, B. (editor); Gosset, B. (editor)

1979-01-01

397

Columbia returning to Kennedy Space Center  

NASA Technical Reports Server (NTRS)

The Space shuttle orbiter Columbia returns to the shuttle landing facility atop NASA 905, a modified 747, following a cross country flight from the Dryden Flight Research Facility. The Kennedy Space Center alternative photo number is 108-KSC-82PC-1328.

1982-01-01

398

Chromosomal assignment of the genes for proprotein convertases PC4, PC5, and PACE 4 in mouse and human  

SciTech Connect

The genes for three subtilisin/kexin-like proprotein convertases, PC4, PC5, and PACE4, were mapped in the mouse by RFLP analysis of a DNA panel from a (C57BL/6JEi x SPRET/Ei) F{sub 1} x SPRET/Ei backcross. The chromosomal locations of the human homologs were determined by Southern blot analysis of a DNA panel from human-rodent somatic cell hybrids, most of which contained a single human chromosome each. The gene for PC4 (Pcsk4 locus) mapped to mouse chromosome 10, close to the Adn (adipsin, a serine protease) locus and near the Amh (anti-Mullerian hormone) locus; in a human, the gene was localized to chromosome 19. The gene for PC5 (Pcsk5 locus) mapped to mouse chromosome 19 close to the Lpc1 (lipoacortin-1) locus and, in human, was localized to chromosome 9. The gene for PACE4 (Pcsk6 locus) mapped to mouse chromosome 7, at a distance of 13 cM from the Pcsk3 locus, which specifies furin, another member of this family of enzymes previoulsy mapped to this chromosome. This is in concordance with the known close proximity of these two loci in the homologous region on human chromosome 15q25-qter. Pcsk3 and Pcsk6 mapped to a region of mouse chromosome 7 that has been associated cytogenetically with postnatal lethality in maternal disomy, suggesting that these genes might be candidates for imprinting. 43 refs., 3 figs., 2 tabs.

Mbikay, M.; Seidah, N.G.; Chretien, M. [Univ. of Montreal, Quebec (Canada)] [and others] [Univ. of Montreal, Quebec (Canada); and others

1995-03-01

399

Application of PC-SAFT to glycol containing systems – PC-SAFT towards a predictive approach  

Microsoft Academic Search

For equations of state of the SAFT type a major limitation is the procedure of obtaining pure compound parameters using saturated vapor pressure and liquid density data. However, for complex compounds such data are often not available. One solution is to develop a group contribution scheme for estimating pure compound parameters from low molecular weight data and extrapolate to complex

Andreas Grenner; Georgios M. Kontogeorgis; Nicolas von Solms; Michael L. Michelsen

2007-01-01

400

Novel phthalocyaninatobis(alkylcarboxylato)silicon(IV) compounds: NMR data and X-ray structures to study the spacing provided by long hydrocarbon tails that enhance their solubility.  

PubMed

The reaction between trans-PcSiCl2 (1) and the potassium salts of six fatty acids (2 a-2 f) led to the trans-PcSi[OOC(CH2)nCH3]2 compounds (3 a-3 f), which were characterised by elemental analysis, IR, UV/Vis and 1H, 13C, and 29Si NMR spectroscopy. From a detailed study of the NMR spectra, the strong anisotropic currents of the Pc macrocycle were found to have an effect on up to the sixth methylenic group. As expected, the length of the hydrocarbon tail does not affect the chemical shift of the 29Si nucleus of any of the compounds, appearing at around -222.6. The structures of PcSi[OOC(CH2)nCH3]2, where n = 7, 10, 12, 13 and 20, were determined by X-ray crystallography. All the compounds were found to be triclinic with a P1 space group. In all cases the observed crystallographic pseudosymmetry is Ci and the asymmetric unit consists of half a molecule. The silicon atom is at the centre of a distorted octahedron and hence its coordination number is six. The carboxylate fragments are in a trans configuration with respect to the Pc macrocycle. The supramolecular structures are discussed in detail herein. The correlation between the 1H NMR chemical shifts and the position of the corresponding carbon atoms in the hydrocarbon tail reveals that the dicarboxylate substituents exhibit a spacer-like behaviour that enhances the solubility. A detailed study of the tail variable allowed us to evaluate the loss of radial shielding along the Pc2- ligand. PMID:15864796

Sosa-Sánchez, Jose L; Sosa-Sánchez, Arturo; Farfán, Norberto; Zamudio-Rivera, Luis S; López-Mendoza, Gerson; Pérez Flores, Javier; Beltrán, Hiram I

2005-07-01

401

CARES/PC - CERAMICS ANALYSIS AND RELIABILITY EVALUATION OF STRUCTURES  

NASA Technical Reports Server (NTRS)

The beneficial properties of structural ceramics include their high-temperature strength, light weight, hardness, and corrosion and oxidation resistance. For advanced heat engines, ceramics have demonstrated functional abilities at temperatures well beyond the operational limits of metals. This is offset by the fact that ceramic materials tend to be brittle. When a load is applied, their lack of significant plastic deformation causes the material to crack at microscopic flaws, destroying the component. CARES/PC performs statistical analysis of data obtained from the fracture of simple, uniaxial tensile or flexural specimens and estimates the Weibull and Batdorf material parameters from this data. CARES/PC is a subset of the program CARES (COSMIC program number LEW-15168) which calculates the fast-fracture reliability or failure probability of ceramic components utilizing the Batdorf and Weibull models to describe the effects of multi-axial stress states on material strength. CARES additionally requires that the ceramic structure be modeled by a finite element program such as MSC/NASTRAN or ANSYS. The more limited CARES/PC does not perform fast-fracture reliability estimation of components. CARES/PC estimates ceramic material properties from uniaxial tensile or from three- and four-point bend bar data. In general, the parameters are obtained from the fracture stresses of many specimens (30 or more are recommended) whose geometry and loading configurations are held constant. Parameter estimation can be performed for single or multiple failure modes by using the least-squares analysis or the maximum likelihood method. Kolmogorov-Smirnov and Anderson-Darling goodness-of-fit tests measure the accuracy of the hypothesis that the fracture data comes from a population with a distribution specified by the estimated Weibull parameters. Ninety-percent confidence intervals on the Weibull parameters and the unbiased value of the shape parameter for complete samples are provided when the maximum likelihood technique is used. CARES/PC is written and compiled with the Microsoft FORTRAN v5.0 compiler using the VAX FORTRAN extensions and dynamic array allocation supported by this compiler for the IBM/MS-DOS or OS/2 operating systems. The dynamic array allocation routines allow the user to match the number of fracture sets and test specimens to the memory available. Machine requirements include IBM PC compatibles with optional math coprocessor. Program output is designed to fit 80-column format printers. Executables for both DOS and OS/2 are provided. CARES/PC is distributed on one 5.25 inch 360K MS-DOS format diskette in compressed format. The expansion tool PKUNZIP.EXE is supplied on the diskette. CARES/PC was developed in 1990. IBM PC and OS/2 are trademarks of International Business Machines. MS-DOS and MS OS/2 are trademarks of Microsoft Corporation. VAX is a trademark of Digital Equipment Corporation.

Szatmary, S. A.

1994-01-01

402

METHANE de-NOX for Utility PC Boilers  

SciTech Connect

The overall project objective is the development and validation of an innovative combustion system, based on a novel coal preheating concept prior to combustion, that can reduce NO{sub x} emissions to 0.15 lb/million Btu or less on utility pulverized coal (PC) boilers. This NO{sub x} reduction should be achieved without loss of boiler efficiency or operating stability, and at more than 25% lower levelized cost than state-of-the-art SCR technology. A further objective is to ready technology for full-scale commercial deployment to meet the market demand for NO{sub x} reduction technologies. Over half of the electric power generated in the U.S. is produced by coal combustion, and more than 80% of these units utilize PC combustion technology. Conventional measures for NOx reduction in PC combustion processes rely on combustion and post-combustion modifications. A variety of combustion-based NO{sub x} reduction technologies are in use today, including low-NO{sub x} burners (LNBs), flue gas recirculation (FGR), air staging, and natural gas or other fuel reburning. Selective non-catalytic reduction (SNCR) and selective catalytic reduction (SCR) are post-combustion techniques. NO{sub x} reduction effectiveness from these technologies ranges from 30 to 60% and up to 90-93% for SCR. Typically, older wall-fired PC burner units produce NO{sub x} emissions in the range of 0.8-1.6 lb/million Btu. Low-NO{sub x} burner systems, using combinations of fuel staging within the burner and air staging by introduction of overfire air in the boiler, can reduce NO{sub x} emissions by 50-60%. This approach alone is not sufficient to meet the desired 0.15 lb/million Btu NO{sub x} standard with a range of coals and boiler loads. Furthermore, the heavy reliance on overfire air can lead to increased slagging and corrosion in furnaces, particularly with higher-sulfur coals, when LNBs are operated at sub-stoichiometric conditions to reduce fuel-derived NOx in the flame. Therefore, it is desirable to minimize the need for overfire air by maximizing NO{sub x} reduction in the burner. The proposed combustion concept aims to greatly reduce NO{sub x} emissions by incorporating a novel modification to conventional or low-NO{sub x} PC burners using gas-fired coal preheating to destroy NO{sub x} precursors and prevent NO{sub x} formation. A concentrated PC stream enters the burner, where flue gas from natural gas combustion is used to heat the PC up to about 1500 F prior to coal combustion. Secondary fuel consumption for preheating is estimated to be 3 to 5% of the boiler heat input. This thermal pretreatment releases coal volatiles, including fuel-bound nitrogen compounds into oxygen-deficient atmosphere, which converts the coal-derived nitrogen compounds to molecular N{sub 2} rather than NO. Design, installation, shakedown, and testing on Powder River Basin (PRB) coal at a 3-million Btu/h pilot system at RPI's (Riley Power, Inc.) pilot-scale combustion facility (PSCF) in Worcester, MA demonstrated that the PC PREHEAT process has a significant effect on final O{sub x} formation in the coal burner. Modifications to both the pilot system gas-fired combustor and the PC burner led to NO{sub x} reduction with PRB coal to levels below 0.15 lb/million Btu with CO in the range of 35-112 ppmv without any furnace air staging.

Bruce Bryan; Serguei Nester; Joseph Rabovitser; Stan Wohadlo

2005-09-30

403

36 CFR 1280.74 - What spaces in the National Archives Building are available for use by non-NARA groups and...  

Code of Federal Regulations, 2010 CFR

... false What spaces in the National Archives Building are available for use by non-NARA...Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION NARA FACILITIES...the Washington, DC, Area? National Archives Building, Washington, Dc §...

2010-07-01

404

36 CFR 1280.74 - What spaces in the National Archives Building are available for use by non-NARA groups and...  

Code of Federal Regulations, 2012 CFR

... false What spaces in the National Archives Building are available for use by non-NARA...Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION NARA FACILITIES...the Washington, DC, Area? National Archives Building, Washington, Dc §...

2012-07-01

405

36 CFR 1280.85 - What space in the National Archives at College Park is available for use by non-NARA groups and...  

Code of Federal Regulations, 2010 CFR

... false What space in the National Archives at College Park is available for use...Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION NARA FACILITIES...the Washington, DC, Area? National Archives at College Park, Md § 1280.85...

2010-07-01

406

36 CFR 1280.85 - What space in the National Archives at College Park is available for use by non-NARA groups and...  

Code of Federal Regulations, 2012 CFR

... false What space in the National Archives at College Park is available for use...Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION NARA FACILITIES...the Washington, DC, Area? National Archives at College Park, Md § 1280.85...

2012-07-01

407

36 CFR 1280.74 - What spaces in the National Archives Building are available for use by non-NARA groups and...  

Code of Federal Regulations, 2013 CFR

... true What spaces in the National Archives Building are available for use by non-NARA...Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION NARA FACILITIES...the Washington, DC, Area? National Archives Building, Washington, Dc §...

2013-07-01

408

36 CFR 1280.74 - What spaces in the National Archives Building are available for use by non-NARA groups and...  

Code of Federal Regulations, 2011 CFR

... false What spaces in the National Archives Building are available for use by non-NARA...Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION NARA FACILITIES...the Washington, DC, Area? National Archives Building, Washington, Dc §...

2011-07-01

409

36 CFR 1280.74 - What spaces in the National Archives Building are available for use by non-NARA groups and...  

Code of Federal Regulations, 2014 CFR

... false What spaces in the National Archives Building are available for use by non-NARA...Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION NARA FACILITIES...the Washington, DC, Area? National Archives Building, Washington, Dc §...

2014-07-01

410

36 CFR 1280.85 - What space in the National Archives at College Park is available for use by non-NARA groups and...  

Code of Federal Regulations, 2014 CFR

... false What space in the National Archives at College Park is available for use...Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION NARA FACILITIES...the Washington, DC, Area? National Archives at College Park, Md § 1280.85...

2014-07-01

411

36 CFR 1280.85 - What space in the National Archives at College Park is available for use by non-NARA groups and...  

Code of Federal Regulations, 2011 CFR

... false What space in the National Archives at College Park is available for use...Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION NARA FACILITIES...the Washington, DC, Area? National Archives at College Park, Md § 1280.85...

2011-07-01

412

Electrochemical evidence of intramolecular electronic communication in Zr and Hf phthalocyanines bearing ferrocene-containing ?-diketonato axial ligands: structure of [PcHf(FcCOCHCOC6H5)2].  

PubMed

The series of zirconium(IV) and hafnium(IV) phthalocyanine complexes [PcM(FcCOCHCOR)2] (Pc = phthalocyaninato; M = Zr; R = CF3 (1), CH3 (2), C6H5 (3), Fc ((C5H5)Fe(C5H4), 4), as well as M = Hf ; R = CF3 (5), CH3 (6), C6H5 (7), and Fc (8)) were synthesized. A single-crystal X-ray diffraction analysis of the structure of [PcHf(FcCOCHCOC6H5)2], 7 (Z = 2, space group P1), showed the two axial ?-diketonato ligands were orientated in such a way that the ferrocenyl groups were positioned diagonally opposite each other. From the structural determination of 7 it was clear that these complexes have a distorted D4h symmetry at the coordination site of the metal centers, which explains a splitting of the UV-vis Q band into Qx and Qy components with 3 ? ??(max,Q) ? 10 nm. Cyclic and square wave voltammetric studies in CH2Cl2/[N((n)Bu)4][B(C6F5)4] allowed observation of at least three phthalocyaninato macrocycle-based redox couples as well as all (i.e., two or four) well-resolved ferrocenyl couples in 1-8. For M = Zr and R = Fc, formal reduction potentials of the four ferrocenyl groups were found to be E°' = 296, 386, 538, and 687 mV versus free ferrocene. Spectroelectrochemical evidence, UV-vis Q-band maximum wavelengths, and HOMO-LUMO energy gaps as expressed by ?E°'I-III = ?E°'wave I - ?E°'wave III were mutually consistent, indicating that the first phthalocyaninato ring-based oxidation occurs before ferrocenyl oxidations take place. The potential for each redox process was found to be dependent on the sum of ?-diketonato R-group group electronegativities, ??R. Mathematical relationships for the dependency of E°' on ??R for all four observed ring-based redox processes as well as for the ferrocenyl-based redox processes were determined. This allowed prediction of potentials for redox processes that fall outside the workable potential window of the solvent. No significant differences were found between the corresponding redox potentials of zirconium and hafnium analogues bearing the same axial ligands. PMID:23971994

Buitendach, Blenerhassitt E; G?gor, Anna; Swarts, Jannie C

2013-09-16

413

PC-based criticality code use at an [open quotes]isolated site[close quotes  

SciTech Connect

Personal computer (PC)-based codes were used to conduct evaluations for subcriticality of fissile material in staging areas at the Pantex plant. The calculations, whose results were used in safety analysis reports (SARS) and a radiological hazards analysis (RHA), were performed by an individual practitioner located off-site. The Pantex evaluations addressed plutonium-metal components, modeling them as identical generic units. The model is conservative for criticality safety purposes in assuming a spherical shell with increased mass and reduced radius, while the plutonium content is treated as if it is all [sup 239]Pu. The computer codes KEN05APC (with 16-group Hansen-Roach cross sections) and MCNP4 (in a package with grouped cross sections) were obtained from the Radiation Shielding Information Center (RSIC). Calculations were performed for arrays of units in various numbers and arrangements with a variety of moderations and reflection conditions and with and without containers.

Knief, R.A. (Ogden Environmental and Energy Services, Albuquerque, NM (United States)); Simpkins, B. (Battelle Pantex, Amarillo, TX (United States))

1993-01-01

414

Real-time visualization of large volume datasets on standard PC hardware.  

PubMed

In medical area, interactive three-dimensional volume visualization of large volume datasets is a challenging task. One of the major challenges in graphics processing unit (GPU)-based volume rendering algorithms is the limited size of texture memory imposed by current GPU architecture. We attempt to overcome this limitation by rendering only visible parts of large CT datasets. In this paper, we present an efficient, high-quality volume rendering algorithm using GPUs for rendering large CT datasets at interactive frame rates on standard PC hardware. We subdivide the volume dataset into uniform sized blocks and take advantage of combinations of early ray termination, empty-space skipping and visibility culling to accelerate the whole rendering process and render visible parts of volume data. We have implemented our volume rendering algorithm for a large volume data of 512 x 304 x 1878 dimensions (visible female), and achieved real-time performance (i.e., 3-4 frames per second) on a Pentium 4 2.4GHz PC equipped with NVIDIA Geforce 6600 graphics card ( 256 MB video memory). This method can be used as a 3D visualization tool of large CT datasets for doctors or radiologists. PMID:18243401

Xie, Kai; Yang, Jie; Zhu, Y M

2008-05-01

415

Space languages  

NASA Technical Reports Server (NTRS)

Applications of linguistic principles to potential problems of human and machine communication in space settings are discussed. Variations in language among speakers of different backgrounds and change in language forms resulting from new experiences or reduced contact with other groups need to be considered in the design of intelligent machine systems.

Hays, Dan

1987-01-01

416

Conversion from 8800 to 8800PC -- Evaluation and experience  

SciTech Connect

Though a final version of the software is pending the 8800PC operating system host computer is a welcomed change from the old Digital (DEC) host computer. The 8800PC host computer uses the Windows NT operating system and has proven to be very user friendly. Descriptive window messages replace the cryptic coding of the DEC host. Though numerous electrical components were replaced, system calibration remained constant. Calibrated Thermoluminescent (TL) output from a randomly selected 8815 field card was measured before and after the upgrade. The % difference, when comparing calibrated output from an upgraded reader to the non upgraded reader, ranged from 0.2 to 3%. The most disappointing aspect of the upgrade experience was the lag time between hardware installation and software completion.

Miner, A.E.; Lawson, B.J. [Lockheed Martin, Schenectady, NY (United States)

1998-03-20

417

Magnetospheric filter effect for Pc 3 Alfven mode waves  

NASA Technical Reports Server (NTRS)

We present a ray-tracing study of the propagation of Pc 3 Alfven mode waves originating at the dayside magnetopause. This study reveals interesting features of a magnetospheric filter effect for these waves. Pc 3 Alfven mode waves cannot penetrate to low Earth altitudes unless the wave frequency is below approximately 30 mHz. Configurations of the dispersion curves and the refractive index show that the gyroresonance and pseudo-cutoff introduced by the heavy ion O(+) block the waves. When the O(+) concentration is removed from the plasma composition, the barriers caused by the O(+) no longer exist, and waves with much higher frequencies than 30 mHz can penetrate to low altitudes. The result that the 30 mHz or lower frequency Alfven waves can be guided to low altitudes agrees with ground-based power spectrum observations at high latitudes.

Zhang, X.; Comfort, R. H.; Gallagher, D. L.; Green, J. L.; Musielak, Z. E.; Moore, T. E.

1994-01-01

418

Magnetospheric filter effect for Pc 3 Alfven mode waves  

NASA Technical Reports Server (NTRS)

We present a ray-tracing study of the propagation of Pc 3 Alfven mode waves originating at the dayside magnetopause. This study reveals interesting features of magnetospheric filter effect for these waves. Pc 3 Alfven mode waves cannot penetrate to low Earth altitudes unless the wave frequency is below approximately 30 mHz. Configurations of the dispersion curves and the refractive index show that the gyroresonance and pseudo-cutoff introduced by the heavy ion O(+) block the waves. When the O(+) concentration is removed from the plasma composition, the barriers caused by the O(+) no longer exist, and waves with much higher frequencies than 30 mHz can penetrate to low altitudes. The result that the 30 mHz or lower frequency Alfven waves can be guided to low altitudes agrees with ground-based power spectrum observation at high altitudes.

Zhang, X.; Comfort, R. H.; Gallagher, D. L.; Green, J. L.; Musielak, Z. E.; Moore, T. E.

1995-01-01

419

Performance characteristics of the Cooper PC-9 centrifugal compressor  

SciTech Connect

Mathematical performance modeling of the PC-9 centrifugal compressor has been completed. Performance characteristics curves have never been obtained for them in test loops with the same degree of accuracy as for the uprated axial compressors and, consequently, computer modeling of the top cascade and purge cascades has been very difficult and of limited value. This compressor modeling work has been carried out in an attempt to generate data which would more accurately define the compressor's performance and would permit more accurate cascade modeling. A computer code, COMPAL, was used to mathematically model the PC-9 performance with variations in gas composition, flow ratios, pressure ratios, speed and temperature. The results of this effort, in the form of graphs, with information about the compressor and the code, are the subject of this report. Compressor characteristic curves are featured. 13 figs.

Foster, R.E.; Neely, R.F.

1988-06-30

420

Four-Channel PC/104 MIL-STD-1553 Circuit Board  

NASA Technical Reports Server (NTRS)

The mini bus interface card (miniBIC) is the first four-channel electronic circuit board that conforms to MIL-STD-1553 and to the electrical-footprint portion of PC/104. [MIL-STD-1553 is a military standard that encompasses a method of communication and electrical- interface requirements for digital electronic subsystems connected to a data bus. PC/104 is an industry standard for compact, stackable modules that are fully compatible (in architecture, hardware, and software) with personal-computer data- and power-bus circuitry.] Prior to the development of the miniBIC, only one- and two-channel PC/104 MIL-STD-1553 boards were available. To obtain four channels, it was necessary to include at least two boards in a PC/104 stack. In comparison with such a two-board stack, the miniBIC takes up less space, consumes less power, and is more reliable. In addition, the miniBIC includes 32 digital input/output channels. The miniBIC (see figure) contains four MIL-STD-1553B hybrid integrated circuits (ICs), four transformers, a field-programmable gate array (FPGA), and an Industry Standard Architecture (ISA) interface. Each hybrid IC includes a MILSTD-1553 dual transceiver, memory-management circuitry, processor interface logic circuitry, and 64Kx16 bits of shared static random access memory. The memory is used to configure message and data blocks. In addition, 23 16-bit registers are available for (1) configuring the hybrid IC for, and starting it in, various modes of operation; (2) reading the status of the functionality of the hybrid IC; and (3) resetting the hybrid IC to a known state. The miniBIC can operate as a remote terminal, bus controller, or bus monitor. The FPGA provides the chip-select and data-strobe signals needed for operation of the hybrid ICs. The FPGA also receives interruption signals and forwards them to the ISA bus. The ISA interface connects the address, data, and control interfaces of the hybrid ICs to the ISA backplane. Each channel is, in effect, a MIL-STD-1553 interface that can operate either independently of the others or else as a redundant version of one of the others. The transformer in each channel provides electrical isolation between the rest of the miniBIC circuitry and the bus to which that channel is connected.

Cox, Gary L.

2004-01-01

421

Polycomb Group Proteins Set the Stage for Early Lineage Commitment  

E-print Network

Precise control of gene expression patterns is critical for the specification of cellular diversity during metazoan development. Polycomb group (PcG) proteins comprise a class of transcriptional modifiers that have dynamic ...

Surface, Lauren Elizabeth

422

A Radio Transient 0.1 pc from Sagittarius A  

Microsoft Academic Search

We report the discovery of a transient radio source 2.7 arcsec (0.1 pc\\u000aprojected distance) South of the Galactic Center massive black hole,\\u000aSagittarius A*. The source flared with a peak of at least 80 mJy in March 2004.\\u000aThe source was resolved by the Very Large Array into two components with a\\u000aseparation of ~0.7 arcsec and characteristic sizes

Geoffrey C. Bower; Doug A. Roberts; Farhad Yusef-Zadeh; Donald C. Backer; W. D. Cotton; W. M. Goss; Cornelia C. Lang; Yoram Lithwick

2005-01-01

423

Pc Micropulsations with Discrete, Latitude-Dependent Frequencies  

Microsoft Academic Search

In this report we present an example of continuous Pc micropulsations with discrete, latitude-dependent frequencies in the H (north-south) components. These pulsations were recorded simultaneously at seven ground-based magnetometer stations ranging in geomag- netic latitude from 58.5øN to 77.7øN. The pulsations exhibited four discrete spectral peaks in the H components (\\/ -- 14.7, 6.6, 4.1, and 1.3 mHz; T --

Gordon Rostoker; John C. Samson

1972-01-01

424

The photodynamic antibacterial effects of silicon phthalocyanine (pc) 4.  

PubMed

The emergence of antibiotic-resistant strains in facultative anaerobic Gram-positive coccal bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), is a global health issue. Typically, MRSA strains are found associated with institutions like hospitals but recent data suggest that they are becoming more prevalent in community-acquired infections. It is thought that the incidence and prevalence of bacterial infections will continue to increase as (a) more frequent use of broad-spectrum antibiotics and immunosuppressive medications; (b) increased number of invasive medical procedures; and (c) higher incidence of neutropenia and HIV infections. Therefore, more optimal treatments, such as photodynamic therapy (PDT), are warranted. PDT requires the interaction of light, a photosensitizing agent, and molecular oxygen to induce cytotoxic effects. In this study, we investigated the efficacy and characterized the mechanism of cytotoxicity induced by photodynamic therapy sensitized by silicon phthalocyanine (Pc) 4 on (a) methicillin-sensitive Staphylococcus aureus (MSSA) (ATCC 25923); (b) community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) (ATCC 43300); and (c) hospital acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) (PFGE type 300). Our data include confocal image analysis, which confirmed that Pc 4 is taken up by all S. aureus strains, and viable cell recovery assay, which showed that concentrations as low as 1.0 ?M Pc 4 incubated for 3 h at 37 °C followed by light at 2.0 J/cm2 can reduce cell survival by 2-5 logs. These results are encouraging, but before PDT can be utilized as an alternative treatment for eradicating resistant strains, we must first characterize the mechanism of cell death that Pc 4-based PDT employs in eliminating these pathogens. PMID:25856680

Dimaano, Matthew L; Rozario, Chantal; Nerandzic, Michelle M; Donskey, Curtis J; Lam, Minh; Baron, Elma D

2015-01-01

425

PC-SPES for treatment of prostate cancer: Herbal medicine  

Microsoft Academic Search

The number of patients who seek treatment with complementary and alternative medicine has increased during the past decade.\\u000a The trend is primarily driven by consumers who start to change their views toward conventional pharmaceutical approaches that\\u000a are offered to them. Among all complementary and alternative therapies used in the management of prostate cancer, Prostate\\u000a Cancer-SPES [Latin for “hope”] (PC-SPES) has

Ian Yip; Michelle Cudiamat; David Chim

2003-01-01

426

A Biochemical Assay for Acetylcholinesterase Activity in PC12 Cells  

NSDL National Science Digital Library

This lab describes two biochemical assays: One for measuring acetylcholinesterase activity and one for measuring protein concentration. Students learn how to manipulate small-volume samples, use a standard spectrophotometer or a microplate reader spectrophotometer, construct a standard curve, and normalize data. The lab is intended to be used in conjunction with a cell culture lab in which PC12 cells are exposed to various agents that influence their phenotypic state.

Paul J. Schwartz (University of Medicine and Dentistry of New Jersey; Department of Neurological Surgery REV)

2007-07-10

427

Western State Hospital: implementing a MUMPS-based PC network.  

PubMed

Western State Hospital, a state-administered 1,200-bed mental health institution near Tacoma, Wash., confronted the challenge of automating its large campus through the application of the Healthcare Integrated Information System (HIIS). It is the first adaptation of the Veterans Administration's Decentralized Hospital Computer Program software in a mental health institution of this size, and the first DHCP application to be installed on a PC client/server network in a large U.S. hospital. PMID:10112114

Russ, D C

1991-06-01

428

Structure and Water Permeability of Fully Hydrated DiphytanoylPC  

PubMed Central

Diphytanoylphosphatidylcholine (DPhyPC) is a branched chain lipid often used for model membrane studies, including peptide/lipid interactions, ion channels and lipid rafts. This work reports results of volume measurements, water permeability measurements Pf, X-ray scattering from oriented samples, and x-ray and neutron scattering from unilamellar vesicles at T=30 °C. We measured the volume/lipid VL = 1426 ± 1 Å3. The area/lipid was found to be 80.5 ± 1.5 Å2 when both x-ray and neutron data were combined with the SDP model analysis (Ku?erka et al., 2008); this is substantially larger than the area of DOPC which has the largest area of the common linear chain lipids. Pf was measured to be 7.0 ± 1.0 ×10?3 cm/sec; this is considerably smaller than predicted by the recently proposed 3-slab model (Nagle et al., 2008). This disagreement can be understood if there is a diminished diffusion coefficient in the hydrocarbon core of DPhyPC and that is supported by previous molecular dynamics simulations (Shinoda et al., 2004). While the DPhyPC head-head thickness (DHH= 36.4 Å), and Hamaker parameter (H=4.5 ×10?21J) were similar to the linear chain lipid DOPC, the bending modulus (KC=5.2 ± 0.5 ×10?21J) was 30% smaller. Our results suggest that, from the biophysical perspective, DPhyPC belongs to a different family of lipids than phosphatidylcholines that have linear chain hydrocarbon chains. PMID:20447383

Tristram-Nagle, Stephanie; Kim, Dong Joo; Akhunzada, Nadia; Ku?erka, Norbert; Mathai, John C.; Katsaras, John; Zeidel, Mark; Nagle, John F.

2010-01-01

429

A versatile PC based control system for channeling experiments  

NASA Astrophysics Data System (ADS)

A PC based control system for aligning the low index directions of a single crystal target with that of a charged particle beam from an accelerator has been designed. Two stepper motors are employed to control the tilt (?) and rotation (?) of the target mounted on a double axis high precision goniometer. A user friendly software using BASIC language is developed for controlling the motors and acquiring data with two detectors simultaneously. Many additional features are also included in the design of the system.

Nanal, Vandana; Fernandes, W.; Kurup, M. B.; Prasad, K. G.

1993-01-01

430

Enabling a PC Cluster for High Performance Computing  

Microsoft Academic Search

Due to their excellent cost\\/performance ratio, clusters of PCs can be attractive high performance computing (HPC) platforms. Yet, their limited communication performance over standard LANs is still prohibitive for parallel applications. The SMiLE project (Shared Memory in a LAN-like Envi- ronment) at LRR-TUM adopts SCI interconnect technology (Scalable Coherent Interface) to build, and provide software for, a PC cluster which,

Hermann Hellwagner; Wolfgang Karl; Markus Leberecht

1997-01-01

431

An automatic wave detection algorithm applied to Pc1 pulsations  

Microsoft Academic Search

A new technique designed to automatically identify and characterize waves in three-axis data is presented, which can be applied in a variety of settings, including triaxial ground-magnetometer data or satellite wave data (particularly when transformed to a field-aligned coordinate system). This technique is demonstrated on a single Pc1 event recorded on a triaxial search coil magnetometer in Parkfield, California (35.945°,?120.542°),

J. Bortnik; J. W. Cutler; C. Dunson; T. E. Bleier

2007-01-01

432

Quantal release of ATP from clusters of PC12 cells  

PubMed Central

Although ATP is important for intercellular communication, little is known about the mechanism of endogenous ATP release due to a dearth of suitable models. Using PC12 cells known to express the P2X2 subtype of ATP receptors and to store ATP with catecholamines inside dense-core vesicles, we found that clusters of PC12 cells cultured for 3–7 days generated small transient inward currents (STICs) after an inward current elicited by exogenous ATP. The amplitude of STICs in individual cells correlated with the peak amplitude of ATP-induced currents. STICs appeared as asynchronous responses (approximately 20 pA average amplitude) for 1–20 s and were investigated with a combination of patch clamping, Ca2+ imaging, biochemistry and electron microscopy. Comparable STICs were produced by focal KCl pulses and were dependent on extracellular Ca2+. STICs were abolished by the P2X antagonist PPADS and potentiated by Zn2+, suggesting they were mediated by P2X2 receptor activation. The highest probability of observing STICs was after the peak of intracellular Ca2+ increase caused by KCl. Biochemical measurements indicated that KCl application induced a significant release of ATP from PC12 cells. Electron microscopy studies showed narrow clefts without ‘synaptic-like’ densities between clustered cells. Our data suggest that STICs were caused by quantal release of endogenous ATP by depolarized PC12 cells in close juxtaposition to the recorded cell. Thus, STICs may be a new experimental model to characterize the physiology of vesicular release of ATP and to study the kinetics and pharmacology of P2X2 receptor-mediated quantal currents. PMID:15331685

Fabbro, Alessandra; Skorinkin, Andrei; Grandolfo, Micaela; Nistri, Andrea; Giniatullin, Rashid

2004-01-01

433

PC based graphic display real-time particle beam uniformity  

SciTech Connect

A technique has been developed to support the study of cosmic ray effects on integrated circuits. The system is designed to accurately determine the particle distribution across the surface of an integrated circuit, while the circuit is bombarded by a particle beam. The system uses photomultiplier tubes, an octal discriminator, a computer controlled NIM Quad Counter, and an IBM PC. It provides real-time operator feedback for fast beam tuning, as well as monitoring momentary fluctuations in the particle beam.

Huebner, M.A.; Malone, C.J.; Smith, L.S.; Soli, G.A. (California Inst. of Tech., Pasadena, CA (USA). Karman Lab. of Fluid Mechanics and Jet Propulsion)

1989-10-01

434

PC-DYMAC: Personal Computer-DYnamic Materials ACcounting  

SciTech Connect

This manual was designed to provide complete documentation for the computer system used by the EBR-II Fuels and Materials Department, Argonne National Laboratory-West (ANL-W) for accountability of special nuclear materials (SNM). This document includes background information on the operation of the Fuel Manufacturing Facility (FMF), instructions on computer operations in correlation with production and a detailed manual for PC-DYMAC operation. 2 refs., 60 figs.

Jackson, B.G.

1990-06-01

435

OAST Space Theme Workshop. Volume 3: Working group summary. 2: Data handling, communications (E-2). A. Statement. B. Technology needs (form 1). C. Priority assessment (form 2)  

NASA Technical Reports Server (NTRS)

Technologies required to support the stated OAST thrust to increase information return by X1000, while reducing costs by a factor of 10 are identified. The most significant driver is the need for an overall end-to-end data system management technology. Maximum use of LSI component technology and trade-offs between hardware and software are manifest in most all considerations of technology needs. By far, the greatest need for data handling technology was identified for the space Exploration and Global Services themes. Major advances are needed in NASA's ability to provide cost effective mass reduction of space data, and automated assessment of earth looking imagery, with a concomitant reduction in cost per useful bit. A combined approach embodying end-to-end system analysis, with onboard data set selection, onboard data processing, highly parallel image processing (both ground and space), low cost, high capacity memories, and low cost user data distribution systems would be necessary.

1976-01-01

436

OAST Space Theme Workshop. Volume 3: Working group summary. 1: Navigation, guidance, control (E-1) A. Statement. B. Technology needs (form 1). C. Priority assessment (form 2)  

NASA Technical Reports Server (NTRS)

The six themes identified by the Workshop have many common navigation guidance and control needs. All the earth orbit themes have a strong requirement for attitude, figure and stabilization control of large space structures, a requirement not currently being supported. All but the space transportation theme have need for precision pointing of spacecraft and instruments. In addition all the themes have requirements for increasing autonomous operations for such activities as spacecraft and experiment operations, onboard mission modification, rendezvous and docking, spacecraft assembly and maintenance, navigation and guidance, and self-checkout, test and repair. Major new efforts are required to conceptualize new approaches to large space antennas and arrays that are lightweight, readily deployable, and capable of precise attitude and figure control. Conventional approaches offer little hope of meeting these requirements. Functions that can benefit from increasing automation or autonomous operations are listed.

1976-01-01

437

Capsaicin induces apoptosis in PC12 cells through ER stress.  

PubMed

Capsaicin, the pungent agent in chili peppers, has been shown to act as a tumor-suppressor in cancer. In our previous study, capsaicin was shown to induce apoptosis in the rat pheochromocytoma cell line (PC12 cells). Thus, the aim of the present study was to determine the potential mechanism by which capsaicin induces apoptosis. We treated PC12 cells with 50, 100 and 500 µM capsaicin and measured the reticular calcium content and expression of the reticular calcium transport systems. These results were correlated with endoplasmic reticulum (ER) stress markers CHOP, ATF4 and X-box binding protein 1 (XBP1), as well as with apoptosis induction. We observed that capsaicin decreased reticular calcium in a concentration-dependent manner. Simultaneously, expression levels of the sarco/endoplasmic reticulum pump and ryanodin receptor of type 2 were modified. These changes were accompanied by increased ER stress, as documented by increased stress markers. Thus, from these results we propose that in PC12 cells capsaicin induces apoptosis through increased ER stress. PMID:24337105

Krizanova, Olga; Steliarova, Iveta; Csaderova, Lucia; Pastorek, Michal; Hudecova, Sona

2014-02-01

438

Hypergravity Stimulation Enhances PC12 Neuron-Like Cell Differentiation  

PubMed Central

Altered gravity is a strong physical cue able to elicit different cellular responses, representing a largely uninvestigated opportunity for tissue engineering/regenerative medicine applications. Our recent studies have shown that both proliferation and differentiation of C2C12 skeletal muscle cells can be enhanced by hypergravity treatment; given these results, PC12 neuron-like cells were chosen to test the hypothesis that hypergravity stimulation might also affect the behavior of neuronal cells, in particular promoting an enhanced differentiated phenotype. PC12 cells were thus cultured under differentiating conditions for either 12?h or 72?h before being stimulated with different values of hypergravity (50?g and 150?g). Effects of hypergravity were evaluated at transcriptional level 1?h and 48?h after the stimulation, and at protein level 48?h from hypergravity exposure, to assess its influence on neurite development over increasing differentiation times. PC12 differentiation resulted strongly affected by the hypergravity treatments; in particular, neurite length was significantly enhanced after exposure to high acceleration values. The achieved results suggest that hypergravity might induce a faster and higher neuronal differentiation and encourage further investigations on the potential of hypergravity in the preparation of cellular constructs for regenerative medicine and tissue engineering purposes. PMID:25785273

2015-01-01

439

Capsaicin induces apoptosis in PC12 cells through ER stress  

PubMed Central

Capsaicin, the pungent agent in chili peppers, has been shown to act as a tumor-suppressor in cancer. In our previous study, capsaicin was shown to induce apoptosis in the rat pheochromocytoma cell line (PC12 cells). Thus, the aim of the present study was to determine the potential mechanism by which capsaicin induces apoptosis. We treated PC12 cells with 50, 100 and 500 ?M capsaicin and measured the reticular calcium content and expression of the reticular calcium transport systems. These results were correlated with endoplasmic reticulum (ER) stress markers CHOP, ATF4 and X-box binding protein 1 (XBP1), as well as with apoptosis induction. We observed that capsaicin decreased reticular calcium in a concentration-dependent manner. Simultaneously, expression levels of the sarco/endoplasmic reticulum pump and ryanodin receptor of type 2 were modified. These changes were accompanied by increased ER stress, as documented by increased stress markers. Thus, from these results we propose that in PC12 cells capsaicin induces apoptosis through increased ER stress. PMID:24337105

KRIZANOVA, OLGA; STELIAROVA, IVETA; CSADEROVA, LUCIA; PASTOREK, MICHAL; HUDECOVA, SONA

2014-01-01

440

Modulation of total electron content by ULF Pc5 waves  

NASA Astrophysics Data System (ADS)

An intriguing effect was found while analyzing the small-scale variations of total electron content (TEC) derived from global positioning system (GPS) signals. We found a response in TEC variations to intense global Pc5 pulsations with periods of a few millihertz covering the corrected geomagnetic latitudes ~58°-75° during the recovery phase of the strong magnetic storms on 31 October 2003. Earlier studies demonstrated that the GPS-TEC technique is a powerful method to study the propagation pattern of transient disturbances in the ionosphere, generated by seismic or internal gravity waves. This technique has turned out to be sensitive enough to ULF waves as well. During periods with intense Pc5 geomagnetic wave activity, distinct pulsations with the same periodicity were found in the TEC data from high-latitude GPS receiving stations in Scandinavia. Wavelet and cross-spectral analysis showed a high coherence (~0.9) between the periodic geomagnetic and TEC variations. Moreover, the relative amplitude of TEC periodic fluctuations ?TEC/TEC was about or even larger than the relative amplitude of geomagnetic variations ?B/B. So far, the effect of TEC modulation by Pc5 waves is not well understood and is still a challenge for the MHD wave theory. Various possible modulation mechanisms have been estimated, but no mechanism has been firmly identified.

Pilipenko, V.; Belakhovsky, V.; Murr, D.; Fedorov, E.; Engebretson, M.

2014-06-01

441

OAST Space Theme Workshop. Volume 3: Working group summary. 7: Material (M-1). A. Statement. B. Technology needs (form 1). C. Priority assessment (form 2)  

NASA Technical Reports Server (NTRS)

The approach of matching technology areas with various themes needs was not effective for the materials and thermal control discipline because of the diversity of requirements for each. Top priorities were evolved from the advanced space transportation system and the space power platform because these are essential building blocks in fulfilling some of the other themes. Important needs identified include life long-life cryogenic cooling systems for sensors, masers, and other devices and the needs for lightweight nuclear shielding materials for nuclear electric propulsion.

1976-01-01

442

OAST Space Theme Workshop. Volume 3: Working group summary. 9: Aerothermodynamics (M-3). A: Statement. B: Technology needs (form 1). C. Priority assessment (form 2). D. Additional assessments  

NASA Technical Reports Server (NTRS)

Twelve aerothermodynamic space technology needs were identified to reduce the design uncertainties in aerodynamic heating and forces experienced by heavy lift launch vehicles, orbit transfer vehicles, and advanced single stage to orbit vehicles for the space transportation system, and for probes, planetary surface landers, and sample return vehicles for solar system exploration vehicles. Research and technology needs identified include: (1) increasing the fluid dynamics capability by at least two orders of magnitude by developing an advanced computer processor for the solution of fluid dynamic problems with improved software; (2) predicting multi-engine base flow fields for launch vehicles; and (3) developing methods to conserve energy in aerothermodynamic ground test facilities.

1976-01-01

443

DIFFERENTIAL MODULATION OF CATECHOLAMINES BY CHLOROTRIAZINE HERBICIDES IN PHEOCHROMOCYTOMA (PC12) CELLS IN VITRO  

EPA Science Inventory

Differential modulation of catecholamines by chlorotriazine herbicides in pheochromocytoma (PC12) cells in vitro. Das PC, McElroy WK, Cooper RL. Curriculum in Toxicology, University of North Carolina, Chapel Hill 27599, USA. Epidemiological, wildlife, and lab...

444

Molecular Modeling on the PC (by Matthew F. Schlecht)  

NASA Astrophysics Data System (ADS)

"Computeraided molecular modeling doesn't exist for its own sake, but to contribute to scientific endeavor, and enable the scientist to work smarter." This is the last sentence of Schlecht's preface and it says something very important about contemporary scientific research in the academic and industrial venues. Owing to the accelerating improvement in computer technology (hardware and software) and its widespread availability, molecular modeling has become a reliable and important tool in chemical research. Consequently, experimentalists have incorporated molecular modeling techniques in their research, and partnerships with computational chemists have become common. This is a wellorganized and thorough monograph that devotes its attention to one type of molecular modeling, molecular mechanics, and one molecular modeling software package, PCMODEL. Schlecht targets two reader-user groups, the novice and the journeyman modeler, and articulates three goals. He wants to provide the novice with an introduction to molecular mechanics, and after that with some practical examples of the use of empirical force field calculations. His third goal is to provide the journeyman modeler with a reference work that will aid "further study and practice". These are potentially conflicting goals, but Schlecht is, in my opinion, successful because of the way his book is organized. A comprehensive treatment such as this one is not meant to be read from cover to cover, because it is both an exposition of basic principles and a user's manual. Therefore, the novice and the experienced modeler will undoubtedly use this book in different ways. For example, a novice modeler might be advised to read the Preface and Chapter 1, which together provide a broad introduction to the historical development and goals of molecular mechanics. From there the novice could go to Chapter 5 and read section 5.1 on the components of the molecular mechanics force field, which is presented in 22 pages with plenty of graphical support. The reader is now ready to move to Chapter 6 on applications and work through the 32 exercises (Chapters 3 and 4 have an additional 11 exercises) designed to illustrate the current uses of molecular modeling in academic and industrial research. Chapter 3 (Input and Output), Chapter 4 (File Formats), and the balance of Chapter 5 can be consulted as needed. For example, Chapter 5 contains 160 pages on the evolution of the various empirical force fields in use today and important information in each case on parameterization and implementation. Besides finding a clearly written, wellorganized, thorough presentation, the reader will appreciate a number of other important features. There are numerous references (993) to the primary literature covering the field of molecular mechanics from its beginnings to mid1997, when the book went to press. There is a complete glossary of PCMODEL commands, and a comprehensive and valuable glossary (77 pages) of frequently used computer terms. There are 392 figures (many of them screen captures) providing illustrations of the PCMODEL interface in use and examples of input and output files. To aid the reader/user in obtaining expertise as a modeler, a diskette containing all the structure files for all the exercises accompanies the text. In addition, the author provides, on the same diskette, a browserreadable HTML file that contains links to a large number of pertinent resources on the World Wide Web. In summary, Molecular Modeling on the PC, by Matthew Schlecht, is a very impressive contribution to the molecular modeling literature. Schlecht's book should be in every college and university library and in the personal libraries of those who want to learn more about molecular mechanics or who anticipate its use in their teaching or research.

Rioux, Reviewed Frank

2000-06-01

445

Identifying gaps in the use of urban green space for BEM (Black and Ethnic Minority) groups in London Borough of Hounslow, West London using GIS approach  

Microsoft Academic Search

The role of high quality green spaces has won a significant place in the London sustainable development agenda as to ensure all Londoners are within the walking distance of a quality nature. To achieve the goal of sustainable living via urban regeneration , each and every part of the society needs to be aware about their role, rights and responsibilities

Rekha Kharel-Bastola

446

36 CFR 1280.85 - What space in the National Archives at College Park is available for use by non-NARA groups and...  

Code of Federal Regulations, 2013 CFR

...2012-07-01 true What space in the National Archives at College Park is available for use...Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION NARA FACILITIES...the Washington, DC, Area? National Archives at College Park, Md § 1280.85...

2013-07-01

447

Genetic screen for novel polycomb group (PcG) genes and targets in Arabidopsis thaliana   

E-print Network

to be identified. In this thesis I brought genetic and molecular evidence showing that CLF, though the PRC2, control floral induction (FLC), floral integration (FT) and floral organ formation (SEP3 and AG) in A. thaliana....

Lo?pez Vernaza, Manuel A.

2009-01-01

448

An overview of the evaluation plan for PC/MISI: PC-based Multiple Information System Interface  

NASA Technical Reports Server (NTRS)

An initial evaluation plan for the personal computer multiple information system interface (PC/MISI) project is discussed. The document is intend to be used as a blueprint for the evaluation of this system. Each objective of the design project is discussed along with the evaluation parameters and methodology to be used in the evaluation of the implementation's achievement of those objectives. The potential of the system for research activities related to more general aspects of information retrieval is also discussed.

Dominick, Wayne D. (editor); Lim, Bee Lee; Hall, Philip P.

1985-01-01

449

Conformal Carroll groups  

NASA Astrophysics Data System (ADS)

Conformal extensions of Lévy-Leblond's Carroll group, based on geometric properties analogous to those of Newton-Cartan space-time are proposed. The extensions are labeled by an integer k. This framework includes and extends our recent study of the Bondi-Metzner-Sachs (BMS) and Newman-Unti (NU) groups. The relation to conformal Galilei groups is clarified. Conformal Carroll symmetry is illustrated by ‘Carrollian photons’. Motion both in the Newton-Cartan and Carroll spaces may be related to that of strings in the Bargmann space.

Duval, C.; Gibbons, G. W.; Horvathy, P. A.

2014-08-01

450

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION  

E-print Network

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION 1 NASA Earth Science Data Systems Software Reuse #12;NATIONAL AERONAUTICS AND SPACE ADMINISTRATION ESDS Reuse Working Group 2 Award Background: http://www.esdswg.com/softwarereuse/Resources/awards/ #12;NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

Christian, Eric

451

Breaking up is hard to do: family perspectives on the future of the home PC  

Microsoft Academic Search

Industry analysts currently disagree about the future of domestic computing. Some predict increasing sales of home PCs while others predict the break-up of the PC into a variety of information appliances. In this paper, we report a study of home PC use which illuminates this issue from the perspective of existing PC-owning families. Eleven PC-owning families from the Boston area

David M. Frohlich; Susan M. Dray; Amy Silverman

2001-01-01

452

Kex2Like Endoproteases PC2 and PC3 Accurately Cleave a Model Prohormone in Mammalian Cells: Evidence for a Common Core of Neuroendocrine Processing Enzymes  

Microsoft Academic Search

Two mammalian gene products, PC2 and PC3, have been proposed as candidate neuroendocrine-precursor processing enzymes based on the structural similarity of their catalytic domains to that of the yeast precursor-processing endoprotease Kex2. In this report we demonstrate that these two proteases can cleave proopiomelanocortin (POMC) in the secretory pathway of mammalian cells. Similarly to pituitary corticotrophs, PC3 expressed in processing-deficient

Laurel Thomas; Richard Leduc; Barbara A. Thorne; Steven P. Smeekens; Donald F. Steiner; Gary Thomas

1991-01-01

453

Evaluation of Manual Spelling, Observational and Incidental Learning Using Computer-Based Instruction with a Tablet PC, Large Screen Projection, and a Forward Chaining Procedure  

ERIC Educational Resources Information Center

The study employed a multiple probe design to investigate the effects of computer-based instruction (CBI) and a forward chaining procedure to teach manual spelling of words to three young adults with moderate intellectual disability in a small group arrangement. The computer-based program included a tablet PC whereby students wrote words directly…

Purrazzella, Kimberly; Mechling, Linda C.

2013-01-01

454

Annotations with a Tablet PC or typed feedback: does it make a difference?  

E-print Network

Annotations with a Tablet PC or typed feedback: does it make a difference? Lyn Brodie University a Tablet PC and was able to provide handwritten feedback. Introduction The work presented in this paper has developed from a USQ Learning and Teaching Fellowship which provided Toshiba Portege M750 Tablet PC's to all

Loch, Birgit

455

Using Research and Projects to Develop Tablet PC Applications for Enhanced Undergraduate Learning  

E-print Network

Using Research and Projects to Develop Tablet PC Applications for Enhanced Undergraduate Learning Pace University, New York Using Research and Projects to Develop Tablet PC Applications for Enhanced to facilitate the use and effective integration of the Tablet PC into undergraduate courses, primarily CIS 101

Tappert, Charles

456

Integrating a Single Tablet PC in Chemistry, Engineering, and Physics Courses  

ERIC Educational Resources Information Center

A tablet PC is a versatile computer that combines the computing power of a notebook with the pen functionality of a PDA (Cox and Rogers 2005b). The authors adopted tablet PC technology in order to improve the process and product of the lecture format in their chemistry, engineering, and physics courses. In this high-tech model, a single tablet PC

Rogers, James W.; Cox, James R.

2008-01-01

457

Low dimensional molecular semiconductor. II. the two-dimensional radicalar bisphthalocyaninato lutetium Pc2Lu (*)  

E-print Network

lutetium Pc2Lu (*) P. Petit and J.-J. André Institut Charles Sadron, 6 rue Boussingault, 67083 Strasbourg of bisphthalocyaninato lutetium, Pc2Lu. The crystalline structure and the magnetic properties determined by ESR reveal: the bisphthalocyan- inato lutetium PC2Lu [2], the other one is a broad band narrow gap semiconductor : the lithium

Paris-Sud XI, Université de

458

21 CFR 868.2500 - Cutaneous oxygen (PcO 2) monitor.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Cutaneous oxygen (PcO 2) monitor. 868.2500 Section...Monitoring Devices § 868.2500 Cutaneous oxygen (PcO 2 ) monitor. (a) Identification. A cutaneous oxygen (PcO2 ) monitor is a...

2014-04-01

459

21 CFR 868.2500 - Cutaneous oxygen (PcO2) monitor.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Cutaneous oxygen (PcO2) monitor. 868.2500 Section...Monitoring Devices § 868.2500 Cutaneous oxygen (PcO2) monitor. (a) Identification. A cutaneous oxygen (PcO2 ) monitor is a...

2011-04-01

460

21 CFR 868.2500 - Cutaneous oxygen (PcO2) monitor.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Cutaneous oxygen (PcO2) monitor. 868.2500 Section...Monitoring Devices § 868.2500 Cutaneous oxygen (PcO2) monitor. (a) Identification. A cutaneous oxygen (PcO2 ) monitor is a...

2010-04-01

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