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1

Space Group Symmetry  

NSDL National Science Digital Library

In this problem set, students are given space group symmetry diagrams for primitive (P) orthorhombic space groups. For each diagram they must write down the symmetry axis (either 2 or 21) that is parallel to each major axis, and give the symmetry plane (a, b, c, n, or m) that is normal (perpendicular)to each. They must also give the simplified Hermann-Mauguin symbol for the space group.

2

FUNDAMENTAL GROUPS AND COVERING SPACES  

Microsoft Academic Search

In this paper, I will briefly develop the theory of fundamental groups and covering spaces of topological spaces. Then I will point toward the manner in which covering spaces can be used prove some cool things in group theory. I presume a cursory knowledge of topological spaces—open and closed sets, continuous functions, and homeomorphisms should be enough background knowledge.

ETHAN JERZAK

3

Hazy Spaces, Tangent Spaces, Manifolds and Groups.  

National Technical Information Service (NTIS)

The results on hazy spaces and the developments leading to hazy manifolds and groups are summarized. Proofs have appeared elsewhere so here examples are considered and some motivation for definitions and constructions in the theorems is analyzed. It is sh...

C. T. J. Dodson

1977-01-01

4

Magnetic space-group types.  

PubMed

The interpretation of Opechowski-Guccione symbols for magnetic space-group types is based on coordinate triplets given in the now superceded International Tables for X-ray Crystallography [(1952), Vol. 1, edited by N. F. M. Henry & K. Lonsdale. Birmingham: Kynoch Press]. Changes to coordinate triplets in International Tables for Crystallography [(1983), Vol. A, edited by Th. Hahn. Dordrecht: Kluwer Academic Publishers] lead to misinterpretations of these symbols. A list is provided here of Opechowski-Guccione symbols for the 1651 magnetic space-group types with their original definitions given independent of International Tables. PMID:11679704

Litvin, D B

2001-10-26

5

Space Interferometry Science Working Group  

NASA Astrophysics Data System (ADS)

Decisions taken by the astronomy and astrophysics survey committee and the interferometry panel which lead to the formation of the Space Interferometry Science Working Group (SISWG) are outlined. The SISWG was formed by the NASA astrophysics division to provide scientific and technical input from the community in planning for space interferometry and in support of an Astrometric Interferometry Mission (AIM). The AIM program hopes to measure the positions of astronomical objects with a precision of a few millionths of an arcsecond. The SISWG science and technical teams are described and the outcomes of its first meeting are given.

Ridgway, Stephen T.

1992-12-01

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

Automorphisms of Free Groups and Outer Space  

Microsoft Academic Search

This is a survey of recent results in the theory of automorphism groups of finitely-generated free groups, concentrating on results obtained by studying actions of these groups on Outer space and its variations.

Karen Vogtmann

2002-01-01

8

Quantum Symmetry Groups of Finite Spaces  

Microsoft Academic Search

We determine the quantum automorphism groups of finite spaces. These are compact matrix quantum groups in the sense of Woronowicz. Dedicated to Marc A. Rieffel on the occasion of his sixtieth birthday

Shuzhou Wang; Marc A. Rieffel

1998-01-01

9

Concept of a multimetrical space group  

NASA Astrophysics Data System (ADS)

A multimetrical space group G is the symmetry group of a pattern having lattice periodicity in an affine space made multimetrical by attaching to it a set of metrics of different signature. The Euclidean metric tensor is always supposed to be a member of the set. The point group K of G is generated by elements leaving the lattice invariant and transforming some of the metric tensors of the set into another one of the same set. When the pattern describes a crystal structure in the point-atom approximation, the Euclidean subgroup G0 of G is the space group of the crystal. When the pattern is defined in superspace, i.e., is obtained by the embedding of a quasicrystal structure (as in the cut-projection method), the subgroup GSR of G leaving the (lower-dimensional) physical space invariant is the scale-space group of the quasicrystal.

Janner, A.

1991-06-01

10

Space transformation for understanding group movement.  

PubMed

We suggest a methodology for analyzing movement behaviors of individuals moving in a group. Group movement is analyzed at two levels of granularity: the group as a whole and the individuals it comprises. For analyzing the relative positions and movements of the individuals with respect to the rest of the group, we apply space transformation, in which the trajectories of the individuals are converted from geographical space to an abstract 'group space'. The group space reference system is defined by both the position of the group center, which is taken as the coordinate origin, and the direction of the group's movement. Based on the individuals' positions mapped onto the group space, we can compare the behaviors of different individuals, determine their roles and/or ranks within the groups, and, possibly, understand how group movement is organized. The utility of the methodology has been evaluated by applying it to a set of real data concerning movements of wild social animals and discussing the results with experts in animal ethology. PMID:24051783

Andrienko, Natalia; Andrienko, Gennady; Barrett, Louise; Dostie, Marcus; Henzi, Peter

2013-12-01

11

Enhancement of electronic and charge transport properties of NiPc by potassium-tetrasulpho group  

NASA Astrophysics Data System (ADS)

We report significant enhancement in the electronic properties of nickel phthalocyanine (NiPc) by attaching a potassium-tetrasulpho functional group to synthesize its water soluble derivative nickel (II)4,4?,4?,4'?potassium-tetrasulphophthalocyanine (K4NiTSPc). To study the potential of this organic compound for electronics applications, Au/K4NiTSPc/Ag diodes have been fabricated and their electronic parameters have been calculated. The mobility and conductivity of the device have been found to be 1.5×10?4 cm2 V?2 S?1 and 2.5×10?4 ??1 cm?1. The K4NiTSPc has shown much better electronic properties as compared to NiPc reported in the literature, which makes it a promising candidate for its potential use in electronics applications.

Ahmad, Zubair; Sayyad, M. H.; Wahab, F.; Sulaiman, Khaulah; Shahid, M.; Chaudry, J. A.; Munawar, M. A.; Aziz, Fakhra

2013-03-01

12

GroupSpace 0.2.0  

NSDL National Science Digital Library

The Internet can serve as a communal gathering place, where like-minded community members can come together to discuss various pressing issues, share documents, take polls, and engage in the decision-making process as well. A recent project, GroupSpace, started at Stanford University as part of a research partnership with a local community organization, allows groups of individuals to do all of the above. As their mission statement suggests, the creation of the program is Âto support the type of deliberation critical to the functioning of smaller, informal organizations in civil societyÂ. It should be noted that this version of GroupSpace is a beta version.

13

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

14

Symmetrized plane waves: 3. nonsymmorphic space groups  

NASA Astrophysics Data System (ADS)

A procedure for systematically constructing symmetrized plane waves, or more generally, arbitrary Bloch-functions, is extended to the case of nonsymmorphic space groups. The technical part to compute those transformations coefficients that are necessary to determine symmetrized plane waves or Bloch-functions, is transferred to a correspondingly tailored software package.

Dirl, R.; Payer, K.; Davies, B. L.

1996-10-01

15

Fourier-Space Crystallography as Group Cohomology  

NASA Astrophysics Data System (ADS)

David Mermin has argued persuasively that the theoretical significance of quasicrystals lies not so much in relaxing the requirement of periodicity as in replacing exact identity of a density function (e.g., electronic or mass) under symmetry operations with indistinguishability of correlation functions, as expressed in Fourier space.(N.D. Mermin, Phys. Stat. Sol. (a) 151), 275 (1995) and references. After reviewing the formalism of Fourier-space crystallography (phase functions and gauge transformations), we present a new formulation in the language of cohomology of groups. First we reexpress the classification of space groups in terms of a first cohomology group; we then show how recent work by König and Mermin(A. König and N.D. Mermin, Am. J. Phys. 68), 525 (2000). on band sticking in nonsymmorphic crystals derives naturally from a first homology group and discuss its connection to a second cohomology group. The new language lets us prove generally several theorems previously known only in special cases. Finally, we let the listener decide whether we're just ``speaking prose.''(N.D. Mermin, Rev. Mod. Phys. 64), 3 (1992).

Rabson, David; Fisher, Benji

2001-03-01

16

Einstein Spaces with a Conformal Group  

Microsoft Academic Search

.  The pseudo-Riemannian Einstein spaces with a (local or global) conformal group of strictly positive dimension can be classified.\\u000a In this article we give a straightforward and systematic proof. As a common generalization, this includes the global theorem\\u000a of Yano and Nagano in the Riemannian case (1959, published in the Annals of Mathematics) and a pseudo-Riemannian analogue\\u000a proved by Kerckhove in

Wolfgang Kühnel; Hans-Bert Rademacher

2009-01-01

17

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

18

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.

2008-01-01

19

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

20

Space Station Group Activities Habitability Module Study.  

National Technical Information Service (NTIS)

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 Re...

D. Nixon

1986-01-01

21

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

SciTech Connect

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/sup 0/ of the geomagnetic equator. Above 10/sup 0/ 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, and odd mode. The wave periods are generally consistent with the fundamental resonant period. In this study, Pc 5 oscillations were identified 3 or 4 times more frequently (per orbit) than in previous spacecraft studies which relied only on magnetic data.

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

1979-12-01

22

Ducting characteristics of Pc 1 waves at high latitudes on the ground and in space  

NASA Astrophysics Data System (ADS)

Well-defined ULF Pc 1 geomagnetic pulsations have been observed simultaneously from a ground array of five search-coil magnetometers in the morning sector of Antarctica on Mar. 23, 2007. Distributed over a very extensive range of geomagnetic latitudes (-62° to -87°, spanning ˜2920 km geographically) approximately along a magnetic meridian, the array showed poleward propagation of the Pc 1 waves in the ionospheric waveguide. It is observed that attenuation factors are between ˜8 and 20 dB/1000 km and the polarization sense changes from left-hand to right-hand as the waves are ducted poleward. However, a complex polarization pattern (i.e., change in ellipticity and major axis angle) was seen on the ground, which might be attributed to the array being close to the wave injection region where the superposed effect of incident waves and ducted waves is dominant. A CHAMP satellite conjunction showed a transverse and nearly linearly polarized Pc 1 ULF wave at the altitude of the ducting layer (˜350 km) over a limited latitudinal extent (-53° to -61° ILAT). The polarization analysis performed using the ground data supports the idea that CHAMP detected the wave activity near the wave injection region. The observations are unique in that the ducted waves, seen over an array with unprecedented geomagnetic latitudinal range and positioning along a magnetic meridian (a condition that provides the most efficient ducting), have rarely been measured before.

Kim, H.; Lessard, M. R.; Engebretson, M. J.; Lühr, H.

2010-09-01

23

Homothety groups in space-time  

NASA Astrophysics Data System (ADS)

This paper investigates space-times which admit anr-dimensional Lie algebra of homothetic vector fields at least one of which is proer homothetic. The situation is resolved completely ifr ? 6 and some general results are given whenr ? 5. Some applications to the study of affine vector fields in space-times are also given and the maximum dimension of this latter algebra is computed and corrects an earlier error.

Hall, G. S.; Steele, J. D.

1990-04-01

24

Actuator grouping optimization on flexible space reflectors  

Microsoft Academic Search

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

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

2011-01-01

25

Meeting of intercosmos space physics group  

Microsoft Academic Search

The 22nd meeting of scientists and specialists of Socialist countries in the Intercosmos program was held in April 1988, in Tbilisi. Taking part in the meeting were well-known Soviet scientists and major foreign specialists from Bulgaria, Hungary, GDR, Cuba, Mongolia, Poland, Rumania, and Czechoslovakia. The meeting focused on a plan for collaboration in space physics for the 1991 to 1995

N. A. Frolova

1989-01-01

26

Interactive 3D Space Group Visualization with CLUCalc and the Clifford Geometric Algebra Description of Space Groups  

Microsoft Academic Search

.  A new interactive software tool is described, that visualizes 3D space group symmetries. The software computes with Clifford\\u000a (geometric) algebra. The space group visualizer (SGV) originated as a script for the open source visual CLUCalc, which fully\\u000a supports geometric algebra computation.\\u000a \\u000a \\u000a Selected generators (Hestenes and Holt, JMP, 2007) form a multivector generator basis of each space group. The approach corresponds

Eckhard Hitzer; Christian Perwass

2010-01-01

27

Optimization of Drilled Shaft Group Spacing.  

National Technical Information Service (NTIS)

The report presents a summary of findings from an assessment of the technical literature, experience of engineers, and unpublished reports on lateral loads on pile groups. Specific interest is adopted in the design methods for drilled shafts, in particula...

B. Douthitt D. N. Frechette K. D. Walsh S. L. Houston W. N. Houston

1999-01-01

28

Tables of crystallographic properties of magnetic space groups.  

PubMed

Tables of crystallographic properties of the reduced magnetic superfamilies of space groups, i.e. the 7 one-dimensional, 80 two-dimensional and 1651 three-dimensional group types, commonly referred to as magnetic space groups, are presented. The content and format are similar to that of non-magnetic space groups and subperiodic groups given in International Tables for Crystallography. Additional content for each representative group of each magnetic space-group type includes a diagram of general positions with corresponding general magnetic moments, Seitz notation used as a second notation for symmetry operations, and general and special positions listed with the components of the corresponding magnetic moments allowed by symmetry. PMID:18421131

Litvin, D B

2008-04-18

29

The functional group on (E)-4,4'-disubstituted stilbenes influences toxicity and antioxidative activity in differentiated PC-12 cells.  

PubMed

This work probes the relationship between stilbene functional group and biological activity. The biological activity of synthesized stilbenes (E)-4,4'-dicyanostilbene, (E)-4,4'-diacetylstilbene, (E)-4,4'-diaminostilbene, a novel stilbene, 1,1'-(vinylenedi-p-phenylene)diethanol, and (E)-stilbene was assessed at biologically relevant nanomolar concentrations using the MTS cell viability assay in differentiated PC-12 cells under optimal culture conditions and conditions of oxidative stress. Under optimal culture conditions the synthesized stilbene derivatives were found to be non-toxic to cells at concentrations up to 10?g/ml. To mimic oxidative stress, the activity of these stilbene derivatives in the presence of 0.03% H2O2 was investigated. Stilbene derivatives with electron-withdrawing functional groups were 2-3 times more toxic than the H2O2 control, indicating that they may form toxic metabolites in the presence of H2O2. Fluorescence data supported that stilbene derivatives with electron-withdrawing functional groups, (E)-4,4'-dicyanostilbene and (E)-4,4'-diacetylstilbene, may react with H2O2. In contrast, the stilbene derivative with a strong electron-donating functional group, (E)-4,4'-diaminostilbene, rescued neurons from H2O2-induced toxicity. The DPPH assay confirmed that (E)-4,4'-diaminostilbene is able to scavenge free radicals. These data indicate that the Hammett value of the functional group correlates with the biological activity of (E)-4,4'-disubstituted stilbenes in differentiated PC-12 cells. PMID:24135726

Garcia, Genevieve X; Larsen, Sean W; Pye, Cameron; Galbreath, Michael; Isovitsch, Ralph; Fradinger, Erica A

2013-10-01

30

Moduli space of many BPS monopoles for arbitrary gauge groups  

Microsoft Academic Search

We study the moduli space for an arbitrary number of BPS monopoles in a gauge theory with an arbitrary gauge group that is maximally broken to U(1)k. From the low energy dynamics of well-separated dyons we infer the asymptotic form of the metric for the moduli space. For a pair of distinct fundamental monopoles, the space thus obtained is R3×(R1×M0)\\/Z,

Kimyeong Lee; Erick J. Weinberg; Piljin Yi

1996-01-01

31

Octonionic Hilbert spaces, the Poincare´ group and SU(3)  

Microsoft Academic Search

A formalism based on real octonions is developed in order to construct an octonionic Hilbert space for the description of colored quark states. The various possible forms of scalar products and related scalars are discussed. The choice of a direction in the space of octonion units leads naturally to a representation of the Poincare´ group in terms of complex scalar

1976-01-01

32

Octonionic Hilbert spaces, the Poincaré group and SU(3)  

Microsoft Academic Search

A formalism based on real octonions is developed in order to construct an octonionic Hilbert space for the description of colored quark states. The various possible forms of scalar products and related scalars are discussed. The choice of a direction in the space of octonion units leads naturally to a representation of the Poincaré group in terms of complex scalar

Murat Günaydin

1976-01-01

33

Isometric Group Actions on Hilbert Spaces: Growth of Cocycles  

Microsoft Academic Search

.  We study growth of 1-cocycles of locally compact groups, with values in unitary representations. Discussing the existence\\u000a of 1-cocycles with linear growth, we obtain the following alternative for a class of amenable groups G containing polycyclic groups and connected amenable Lie groups: either G has no quasi-isometric embedding into a Hilbert space, or G admits a proper cocompact action on

Yves de Cornulier; Romain Tessera; Alain Valette

2007-01-01

34

SPACE TELESCOPE IMAGING SPECTROGRAPH SPECTROSCOPY OF THE CENTRAL 14 pc OF NGC 3998: EVIDENCE FOR AN INFLOW  

SciTech Connect

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{alpha}, H{beta}, and H{gamma} emission line profiles. The analysis indicates that the BELR is large with an outer radius {approx}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 x 10{sup 3} cm{sup -3} as indicated by the broad forbidden [S II] emission line ratio, then interpreting the broad H{alpha} emission line in terms of a steady state spherically symmetric inflow leads to a rate {<=} 6.5 x 10{sup -2} M{sub sun} yr{sup -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, E-mail: devereux@erau.edu [Department of Physics, Embry-Riddle Aeronautical University, Prescott, AZ 86301 (United States)

2011-02-01

35

Radiological Protection in Space: Indication from the ICRP Task Group  

NASA Astrophysics Data System (ADS)

In 2007 the International Commission on Radiological Protection (ICRP) has established a Task Group (Radiation Protection in Space) dealing with the problems of radiation protection of astronauts in space missions. Its first task is a report on "Assessment of Radiation Exposure of Astronauts in Space". When the ICRP published its general recommendations for radiological protection in 2007 (ICRP Publication 103 following ICRP Publication 60 (1991)) it was obvious that these recommendations do not really consider the special situation of astronauts in space. The radiation field with its high content of charged particles of very high energies strongly differs from usual radiation fields on ground. For example, this has consequences for the assessment of doses in the body of astronauts. The ICRP Task Group has discussed this situation and the presentation will deal with some consequences for the concept of radiation dosimetry and radiological protection in space. This includes e. g. the assessment of organ doses and the application of the effective dose concept with its definition of radiation weighting factors. Radiation quality of high energy heavy ions may be defined different than usually performed on ground. An approach of using the quality factor concept in the definition of an "effective dose" is favored for application in space missions similar to the method proposed in NCRP Report 142. New data calculated on the basis of the reference anthropomorphic voxel phantoms recommended by ICRP support this procedure. Individual dosimetry is a further subject of discussion in the Task Group. While the operational dose equivalent quantities generally in use in radiation protection on ground are not helpful for applications in space, different procedures of the assessment of organ and effective doses are applied. The Task Group is dealing with this situation.

Dietze, Günther

36

Octonionic Hilbert spaces, the Poincare group and SU(3). [scalars, Poincare group, real octonions, colored states  

Microsoft Academic Search

A formalism based on real octonions is developed in order to construct an octonionic Hilbert space for the description of colored quark states. The various possible forms of scalar products and related scalars are discussed. The choice of a direction in the space of octonion units leads naturally to a representation of the Poincare group in terms of complex scalar

Gunaydin

1976-01-01

37

Group Action Recognition Using Space-Time Interest Points  

Microsoft Academic Search

Group action recognition is a challenging task in computer vision due to the large complexity induced by multiple motion patterns.\\u000a This paper aims at analyzing group actions in video clips containing several activities. We combine the probability summation\\u000a framework with the space-time (ST) interest points for this task. First, ST interest points are extracted from video clips\\u000a to form the

Qingdi Wei; Xiaoqin Zhang; Yu Kong; Weiming Hu; Haibin Ling

2009-01-01

38

Epigenetic chromatin modifiers in barley: IV. The study of barley Polycomb group (PcG) genes during seed development and in response to external ABA  

Microsoft Academic Search

BACKGROUND: Epigenetic phenomena have been associated with the regulation of active and silent chromatin states achieved by modifications of chromatin structure through DNA methylation, and histone post-translational modifications. The latter is accomplished, in part, through the action of PcG (Polycomb group) protein complexes which methylate nucleosomal histone tails at specific sites, ultimately leading to chromatin compaction and gene silencing. Different

Aliki Kapazoglou; Alessandro Tondelli; Dimitra Papaefthimiou; Helen Ampatzidou; Enrico Francia; Michele A Stanca; Konstantinos Bladenopoulos; Athanasios S Tsaftaris

2010-01-01

39

Optical Fiber Assemblies for Space Flight from the NASA Goddard Space Flight Center, Photonics Group  

Microsoft Academic Search

The Photonics Group at NASA Goddard Space Flight Center in the Electrical Engineering Division of the Advanced Engineering and Technologies Directorate has been involved in the design, development, characterization, qualification, manufacturing, integration and anomaly analysis of optical fiber subsystems for over a decade. The group supports a variety of instrumentation across NASA and outside entities that build flight systems. Among

Melanie N. Ott; William Joe; Robert Switzer; Lance Day

40

Topological classification of crystalline insulators with space group symmetry  

SciTech Connect

We show that in crystalline insulators, space group symmetry alone gives rise to a topological classification based on the discretization of electric polarization. Using C3 rotational symmetry as an example, we first prove that the polarization is discretized into three distinct classes, i.e., it can only take three inequivalent values. We then prove that these classes are topologically distinct. Therefore, a Z3 topological classification exists, with polarization as a topological class index. A concrete tight-binding model is derived to demonstrate the Z3 topological phase transition. Using first-principles calculations, we identify graphene on a BN substrate as a possible candidate to realize these Z3 topological states. To complete our analysis, we extend the classification of band structures to all 17 two-dimensional space groups. This work will contribute to a complete theory of symmetry-conserved topological phases and also elucidate topological properties of graphenelike systems.

Jadaun, Priyamvada [University of Texas at Austin; Xiao, Di [Carnegie Mellon University (CMU); Niu, Q. [University of Texas at Austin; Banerjee, Sanjay K. [University of Texas at Austin

2013-01-01

41

Ducting Characteristics of Pc 1-2 Waves at High Latitudes on the Ground and in Space  

Microsoft Academic Search

Well-defined Pc 1-2 type geomagnetic pulsations and poleward ducting have been observed from a ground array of search-coil magnetometers in the morning sector of Antarctica. With extensive coverage from geomagnetic latitudes of 62° to 87° and good alignment along the magnetic meridian, the five search-coil magnetometers operating aboard American Automated Geophysical Observatories (AGOs) and British Antarctic Survey (BAS) showed very

H. Kim; M. Lessard; M. Engebretson

2008-01-01

42

Recommendations of the Space Interferometry Science Working Group  

NASA Astrophysics Data System (ADS)

The Space Interferometry Science Working Group (SISWG), soon to be disbanded, has spent four years helping with NASA's entry into space interferometry. The Working Group's initial charge was to help with the selection of the Astrometric Interferometry Mission (AIM) design and to advise on long term interferometry strategy. Events have overtaken the original goals. Programmatic concerns and the Future Mission Concepts reviews resulted in the focus landing on the Orbiting Stellar Interferometer (OSI) design. The rapidly developing roadmap for the detection and characterization of Earth-like planets has created a need for early technology development in interferometry. And the dramatic gains in the fields of adaptive optics and ground-based interferometry have shown that space is not the only location for high-spatial-resolution imaging and spectroscopy. Against this background, the science enabled by a 1000-fold improvement in wide angle positional accuracy (compared to Hipparchus) coupled with the major role in technology development, leaves the Space Interferometry Mission (SIM, an expanded OSI instrument) in a secure role. The narrowly focused, but electrifying science of the nulling IR interferometer/spectrometer designed for the planet search is correspondingly unique and secure. Funding of conceptual studies through the Future Missions Concepts program is allowing a close look at the potential of a mid-IR, 25m baseline, imaging interferometer (the Dilute Lens Imager) and of a widely Separated Spacecraft Interferometer (SSI) designed to test a highly dilute interferometer over baselines of up to 10 km. While not without complications, the birth of optical/IR interferometry in space seems well on schedule.

Peterson, D.

1995-12-01

43

Groups acting on finite dimensional spaces with finite stabilizers  

Microsoft Academic Search

.   It is shown that every H\\u000a \\u000a -group G of type admits a finite dimensional G-CW-complex X with finite stabilizers and with the additional property that for each finite subgroup H, the fixed point subspace X\\u000a \\u000a \\u000a \\u000a H\\u000a \\u000a is contractible. This establishes conjecture (5.1.2) of [9]. The construction of X involves joining a family of spaces parametrized by the poset of

Peter H. Kropholler; Guido Mislin

1998-01-01

44

Grouping Miller-Nicely by linear vector space rotations  

NASA Astrophysics Data System (ADS)

Human speech recognition has been studied using response to CV speech stimuli. Miller and Nicely (1955) studied such data in the form of confusion matrices to obtain insight into the psychological structure of the phone in noise. Here, the confusion matrices are modeled as phone coordinates in a high dimensional perceptual vector space. The model generalizes to an eigenvalue decomposition (EVD) [Allen (2004)]. This is followed by agglomerative hierarchical clustering of the transformed data, and an automated process is used to identify the main clusters. The resulting EVD clustering is very similar to other Miller-Nicely groupings, based on both production and MDS derived features, but is more model based. It was found that there is a gradual and highly consistent change in the clustering of sounds, independent of cluster size and configuration. By examining the change in similarity between various speech sounds, it is hoped that perceptual features may be uniquely identified.

Budhlakoti, Suvrat; Allen, Jont B.; Larsen, Erik

2001-05-01

45

Ducting Characteristics of Pc 1-2 Waves at High Latitudes on the Ground and in Space  

NASA Astrophysics Data System (ADS)

Well-defined Pc 1-2 type geomagnetic pulsations and poleward ducting have been observed from a ground array of search-coil magnetometers in the morning sector of Antarctica. With extensive coverage from geomagnetic latitudes of 62° to 87° and good alignment along the magnetic meridian, the five search-coil magnetometers operating aboard American Automated Geophysical Observatories (AGOs) and British Antarctic Survey (BAS) showed very clear poleward ducting with spectral power attenuation of the ULF waves. Halley Station, located at the lowest latitude, observed the highest spectral wave power and well-defined band-limited signatures with the same wave event, showing less wave power, found at the other four remote stations at higher latitudes. This is a clear implication of the poleward ducting of the electromagnetic ion cyclotron (EMIC) waves in the ionospheric waveguide, which are generated from the equatorial magnetosphere along the geomagnetic field lines and transmitted to the ionosphere. Since the wave event was observed over a very wide range in latitude, the observation of the wave propagation will provide significant information on the ULF wave ducting in the waveguide and the source region. This study focuses on the ducting event by comparing the attenuation in the spectral power, the time-delays, and the polarization of the waves recorded from the ground stations. In addition, CHAMP satellite data analysis is also presented to validate the wave ducting.

Kim, H.; Lessard, M.; Engebretson, M.

2008-05-01

46

PC Webopedia  

NSDL National Science Digital Library

Ever wonder what a Routing Switch is? How about CMOS or seek time? Look no further than the PC Webopedia. Provided by The Tech Museum of Innovation, this encyclopedia of computer terms contains over 4,000 entries. Users may search by keyword or browse within 25 categories. Terms are briefly but clearly explained, with links to related terms and, when possible, related Websites.

47

LINE-TRANSITIVE AUTOMORPHISM GROUPS OF LINEAR SPACES  

Microsoft Academic Search

A linear space Sfisa. set & of points, together with a set if of distinguished subsets called lines, such that any two points lie on exactly one line. In this paper we shall be concerned with linear spaces in which every line has the same number of points, and we shall call such a system a regular linear space. Moreover,

ALAN R. CAMINA; CHERYL E. PRAEGER

2000-01-01

48

On position-space renormalization group approach to percolation  

NASA Astrophysics Data System (ADS)

In a position-space renormalization group (PSRG) approach to percolation one calculates the probability R(p,b) that a finite lattice of linear size b percolates, where p is the occupation probability of a site or bond. A sequence of percolation thresholds p c (b) is then estimated from R(p c , b)=p c (b) and extrapolated to the limit b?? to obtain p c = p c (?). Recently, it was shown that for a certain spanning rule and boundary condition, R(p c , ?)=R c is universal, and since p c is not universal, the validity of PSRG approaches was questioned. We suggest that the equation R(p c , b)=?, where ? is any number in (0,1), provides a sequence of p c (b)'s that always converges to p c as b??. Thus, there is an envelope from any point inside of which one can converge to p c . However, the convergence is optimal if ?= R c . By calculating the fractal dimension of the sample-spanning cluster at p c , we show that the same is true about any critical exponent of percolation that is calculated by a PSRG method. Thus PSRG methods are still a useful tool for investigating percolation properties of disordered systems.

Sahimi, Muhammad; Rassamdana, Hossein

1995-02-01

49

Groups of hierarchomorphisms of trees and related Hilbert spaces  

Microsoft Academic Search

Consider an infinite tree. A hierarchomorphism (spheromorphism) is a\\u000ahomeomorphism of the absolute which can be extended to the tree except a finite\\u000asubtree. Examples of groups of hierarchomorphisms: groups of locally analitic\\u000adiffeomorphisms of $p$-adic line; also Richard Thompson groups. The groups of\\u000ahierarchomorphisms have some properties similar to the group of diffeomorphisms\\u000aof the circle. We discuss actions

Yurii A. Neretin

2003-01-01

50

Moving a Media Space into the Real World through Group Robot Interaction  

Microsoft Academic Search

New generation media spaces let group members see each other and share information. However, they are separate from the real world; participants cannot see beyond the video, and they cannot engage with people not attending to the computer. To solve this problem, we use a robot as a physical surrogate for a media space group, which allows this distance-separated group

Jim Young; Gregor McEwan; Saul Greenberg; Ehud Sharlin

2007-01-01

51

Study of liquid crystal space groups using controlled tilting with cryogenic transmission electron microscopy.  

PubMed

We developed a method that enables differentiation between liquid crystalline-phase particles corresponding to different space groups. It consists of controlled tilting of the specimen to observe different orientations of the same particle using cryogenic transmission electron microscopy. This leads to the visualization of lattice planes (or reflections) that are present for a given structure and absent for the other one(s) and that give information on liquid crystalline structures and their space groups. In particular, we show that we can unambiguously distinguish among particles having the inverted micellar cubic (space group Fd(3)m, 227), the inverted bicontinuous gyroid (space group Ia(3)d, 230), the inverted bicontinuous diamond (space group Pn(3)m, 224), and the inverted bicontinuous primitive cubic structure (space group Im(3)m, 229). PMID:17949111

Sagalowicz, Laurent; Acquistapace, Simone; Watzke, Heribert J; Michel, Martin

2007-10-20

52

Tall tales from de Sitter space I: Renormalization group flows  

Microsoft Academic Search

We study solutions of Einstein gravity coupled to a positive cosmological constant and matter which are asymptotically de Sitter and homogeneous. Regarded as perturbations of de Sitter space, a theorem of Gao and Wald implies that generically these solutions are `tall', meaning that the perturbed universe lives through enough conformal time for an entire spherical Cauchy surface to enter any

Frédéric Leblond; Robert C. Myers

2002-01-01

53

POLYIMIDES CONTAINING PENDENT PHOSPHINE OXIDE GROUPS FOR SPACE APPLICATIONS  

Microsoft Academic Search

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

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

54

On the Fourier transform for a symmetric group homogeneous space  

Microsoft Academic Search

By using properties of the Young orthogonal representation, this paper derives a simple form for the Fourier transform of permutations acting on the homogeneous space of $n$-dimensional vectors, and shows that the transform requires $2n-2$ multiplications and the same number of additions.

Ramakrishna Kakarala

2009-01-01

55

Complete derivation of space groups of magnetic symmetry of crystals by numerical construction  

SciTech Connect

The solution is given to the problem regarding the derivation of the so-called space groups of magnetic symmetry with crystallographic angles of rotation of the spin vector, which was formulated as far back as the early 1970s. The crystallographic P-symmetries that should be used in the generalization with the three-dimensional space Fedorov groups G{sub 3} are revealed. The space groups G{sub 3} are generalized with each of these P-symmetries.

Palistrant, A. F. [State University of Moldova (Moldova, Republic of)], E-mail: mepalistrant@yandex.ru

2007-11-15

56

Exploration of Halley's comet from space: the Inter-Agency Consultative Group (IACG) and its associated working groups.  

NASA Astrophysics Data System (ADS)

After 76 years, Halley's comet is again approaching the inner solar system. A fleet of six spacecraft, from four space agencies, is being prepared to encounter the comet in March 1986. The four space agencies have agreed to coordinate informally all matters related to the space missions to Halley's comet and have formed the Inter-Agency Consultative Group (IACG) for this purpose. Since its formation in 1981 the IACG has demonstrated an evergrowing usefulness for the various flight projects as a focal point for exchange of information, discussion on common problems and mutual support to enhance the overall scientific return of the space missions to Halley's comet.

Reinhard, R.

57

Distributions on Minkowski space and their connection with analytic representations of the conformal group  

Microsoft Academic Search

Unitary analytic representations of the conformal group are relized on Hilbert spaces of holomoprhic or antiholomorphic functions over a tube domain in complex Minkowski space. The distributional boundary values of these functions are tempered distributions on real Minkowski space. The representations are characterized by an integral scale dimension labeln and two spin labelsj1 andj2. The connection between the dimensionn and

W. Rühl

1972-01-01

58

The space groups of icosahedral quasicrystals and cubic, orthorhombic, monoclinic, and triclinic crystals  

NASA Astrophysics Data System (ADS)

In 1962 Bienenstock and Ewald described a simple and systematic method for computing all the crystallographic space groups in Fourier space. Their approach is reformulated and further simplified, starting from the definition of the point group of a structure as the set of operations that take it into something indistinguishable and not merely identical to within a translation. The reformulation does not require periodicity, making it possible to define and compute on an equal footing the space groups for crystals, quasicrystals, and incommensurately modulated structures, without having to digress into the crystallography of unphysically many dimensions, and using only simple geometry and the most elementary properties of symmetry groups. The general scheme is illustrated by a unified computation of all the icosahedral, cubic, orthorhombic, monoclinic, and triclinic space groups. The remaining (axial) crystallographic and quasicrystallographic space groups have been discussed in a companion paper.

Mermin, N. David

1992-01-01

59

Space Weather Activities of IONOLAB Group: TEC Mapping  

NASA Astrophysics Data System (ADS)

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 by using dual-frequency GPS receivers. Since these measurements are sparse in space, accurate and robust interpolation techniques are needed to interpolate (or map) the TEC distribution for a given region in space. However, the TEC data derived from GPS measurements contain measurement noise, model and computational errors. Thus, it is necessary to analyze the interpolation performance of the techniques on synthetic data sets that can represent various ionospheric states. By this way, interpolation performance of the techniques can be compared over many parameters that can be controlled to represent the desired ionospheric states. In this study, Multiquadrics, Inverse Distance Weighting (IDW), Cubic Splines, Ordinary and Universal Kriging, Random Field Priors (RFP), Multi-Layer Perceptron Neural Network (MLP-NN), and Radial Basis Function Neural Network (RBF-NN) are employed as the spatial interpolation algorithms. These mapping techniques are initially tried on synthetic TEC surfaces for parameter and coefficient optimization and determination of error bounds. Interpolation performance of these methods are compared on synthetic TEC surfaces over the parameters of sampling pattern, number of samples, the variability of the surface and the trend type in the TEC surfaces. By examining the performance of the interpolation methods, it is observed that both Kriging, RFP and NN have important advantages and possible disadvantages depending on the given constraints. It is also observed that the determining parameter in the error performance is the trend in the Ionosphere. Optimization of the algorithms in terms of their performance parameters (like the choice of the semivariogram function for Kriging algorithms and the hidden layer and neuron numbers for MLP-NN) mostly depend on the behavior of the ionosphere at that given time instant for the desired region. The sampling pattern and number of samples are the other important parameters that may contribute to the higher errors in reconstruction. For example, for all of the above listed algorithms, hexagonal regular sampling of the ionosphere provides the lowest reconstruction error and the performance significantly degrades as the samples in the region become sparse and clustered. The optimized models and coefficients are applied to regional GPS-TEC mapping using the IONOLAB-TEC data (www.ionolab.org). Both Kriging combined with Kalman Filter and dynamic modeling of NN are also implemented as first trials of TEC and space weather predictions.

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

2009-04-01

60

Group theoretical construction of mutually unbiased bases in Hilbert spaces of prime dimensions  

Microsoft Academic Search

Mutually unbiased bases in Hilbert spaces of finite dimensions are closely related to the quantal notion of complementarity. An alternative proof of existence of a maximal collection of (N +1 ) mutually unbiased bases in Hilbert spaces of prime dimension N is given by exploiting the finite Heisenberg group (also called the Pauli group) and the action of SL(2, ZN

61

Harmonic analysis and systems of covariance for phase space representation of the poincaré group  

Microsoft Academic Search

Continuing some earlier work on the Galilei group, the spectral resolution of phase space representations of the Poincaré group is achieved by deriving all possible decompositions into irreducible representations corresponding to reproducing, kernel Hilbert spaces. Systems of covariance related to quantum measurements performed with extended test particles are analyzed, and questions of global unitarity discussed.

S. Twareque Ali; Eduard Prugove?ki

1986-01-01

62

Invariant-theoretic method for calculating Clebsch-Gordan coefficients for space groups  

SciTech Connect

A new invariant-theoretic method to directly calculate Clebsch-Gordan coefficients for space and point groups representations is proposed. The method is exemplified with the space groups O{sub h}{sup 5} and D{sub 6h}{sup 1}. 34 refs.

Aizenberg, A.Ya.; Gufan, Yu.M. [North Caucasus Research Center, Rostov-na-Donu (Russian Federation)

1995-03-01

63

NATO RTO Space Science and Technology Advisory Group (SSTAG) Recommendations for Space Research Topics.  

National Technical Information Service (NTIS)

As NATO and Nations are facing increased global responsibilities for security and defence with smaller forces, the ability to meet objectives will increasingly depend on use of integral, force-enhancing support from space. In recognition of this trend for...

2007-01-01

64

The dynamics of group codes: State spaces, trellis diagrams, and canonical encoders  

Microsoft Academic Search

A group code C over a group G is a set of sequences of group elements that itself forms a group under a component-wise group operation. A group code has a well-defined state space ?k at each time k. Each code sequence passes through a well-defined state sequence. The set of all state sequences is also a group code, the

G. David Forney Jr.; Mitchell D. Trott

1993-01-01

65

Exploration of the Chemical Space of Group 4 Polymer Dielectrics  

NASA Astrophysics Data System (ADS)

The current standards for capacitive energy storage applications are polypropylene (PP) and polyethylene (PE) which have large band gap and high breakdown strength, but a small dielectric constant. The envisaged next generation dielectric should provide high dielectric constant, while still preserving the insulating characteristics of PP and PE. To meet these growing needs, we use high throughput density functional theory (DFT) calculations in combination with machine learning (ML) methods to identify classes of polymers with large dielectric constant and band gap. In our work, we consider various possible local chemical modifications to polyethylene (PE). To be specific, we allow the -CH2- unit in the PE backbone segment to be replaced by -SiF2-, -SiCl2-, -GeF2-, -GeCl2-, -SnF2-, or -SnCl2- units in a systematic manner. High throughput methods were used first to accurately determine the dielectric constant and band gap of the chemically modified PE chains for a set of limited compositions and configurations. ML methods were then used to predict the properties of systems spanning a much larger part of the configurational and compositional space. A set of most promising PE modifications (with simultaneously large dielectric constant and band gap) is identified using this strategy.

Wang, Chenchen; Pilania, Ghanshyam; Ramprasad, Rampi

2013-03-01

66

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

67

Extended weight semigroups of affine spherical homogeneous spaces of non-simple semisimple algebraic groups  

NASA Astrophysics Data System (ADS)

The extended weight semigroup of a homogeneous space G/H of a connected semisimple algebraic group G characterizes the spectra of the representations of G on spaces of regular sections of homogeneous line bundles over G/H, including the space of regular functions on G/H. We compute the extended weight semigroups for all strictly irreducible affine spherical homogeneous spaces G/H, where G is a simply connected non-simple semisimple complex algebraic group and H is a connected closed subgroup of G. In all cases we also find the highest-weight functions corresponding to the indecomposable elements of this semigroup. Among other things, our results complete the computation of the weight semigroups for all strictly irreducible simply connected affine spherical homogeneous spaces of semisimple complex algebraic groups.

Avdeev, Roman S.

2010-12-01

68

Schwinger representation for the symmetric group: Two explicit constructions for the carrier space  

NASA Astrophysics Data System (ADS)

We give two explicit constructions for the carrier space for the Schwinger representation of the group S. While the first relies on a class of functions consisting of monomials in antisymmetric variables, the second is based on the Fock space associated with the Greenberg algebra.

Chaturvedi, S.; Marmo, G.; Mukunda, N.; Simon, R.

2008-05-01

69

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

Microsoft Academic Search

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

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

2006-01-01

70

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

71

Effects of group size and floor space allowance on grouped sows: Aggression, stress, skin injuries, and reproductive performance.  

PubMed

A total of 3,120 sows, in 4 time replicates, were used to determine the effects of group size and floor space on sow welfare using behavioral, physiological, health, and fitness variables. Within 1 to 7 d postinsemination, sows were assigned randomly to treatments of a 3 by 6 factorial arrangement, with 3 group sizes (10, 30, or 80 sows/pen) and 6 floor space allowances (1.4, 1.8, 2.0, 2.2, 2.4, or 3.0 m(2)/sow). Sows were housed on partially slatted concrete floors, and overhead feeders delivered 4 times/day to provide a total of 2.5 kg of feed/sow. As pen space increased from 1.4 to 3.0 m(2)/sow, aggression at feeding decreased from about 9 to 7 bouts/sow (linear, P = 0.029) and plasma cortisol concentrations decreased from about 28 to 21 ng/mL (linear, P = 0.0089) at 2 d. Although the results are in accord with a linear decline from 1.4 to 3 m(2)/sow, the results are also in accord with a decline in these measurements from 1.4 to 1.8 m(2)/sow and no further decline greater than 1.8 m(2)/sow. Farrowing rate (percentage of inseminated sows that farrowed) also increased from about 60 to 75% as space increased from 1.4 to 3.0 m(2)/sow (linear, P = 0.012). Group size was related to skin injuries on d 9 (P = 0.0017), 23 (P = 0.0046), and 51 (P = 0.0006), with groups of 10 consistently having the lowest number of total injuries over this period. Based on the aggression and cortisol results, it is credible to judge that, within the range of floor space allowances studied, sow welfare improves with increased space. However, from a sow welfare perspective, the experiment had insufficient precision to determine what is an adequate space allowance for sows. Thus, although the results definitely support a space allowance of 1.4 m(2)/sow being too small, it is not possible to give guidance on an actual space allowance at mixing that is adequate. PMID:23893983

Hemsworth, P H; Rice, M; Nash, J; Giri, K; Butler, K L; Tilbrook, A J; Morrison, R S

2013-07-26

72

Criteria for weak and strong continuity of representations of topological groups in Banach spaces  

SciTech Connect

Several necessary and sufficient conditions for weak and strong continuity of representations of topological groups in Banach spaces are obtained. In particular, it is shown that a representation S of a locally compact group G in a Banach space is continuous in the strong (or, equivalently, in the weak) operator topology if and only if for some real number q, 0{<=}q<1, and each unit vector {xi} in the representation space of S there exists a neighbourhood U=U({xi}) subset of G of the identity element e element of G such that ||S(g){xi}-{xi}||{<=}q for all g element of U. Versions of this criterion for other classes of groups (including not necessarily locally compact groups) and refinements for finite-dimensional representations are obtained; examples are discussed. Applications to the theory of quasirepresentations of topological groups are presented.

Shtern, A I [M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

2002-10-31

73

OPERATOR K-THEORY FOR GROUPS WHICH ACT PROPERLY AND ISOMETRICALLY ON HILBERT SPACE  

Microsoft Academic Search

Let G be a countable discrete group which acts isometrically and metrically properly on an innite-dimensional Euclidean space. We calculate the K-theory groups of the C-algebras C max(G )a nd Cred(G). Our result is in accordance with the Baum-Connes conjecture.

NIGEL HIGSON; GENNADI KASPAROV

1997-01-01

74

Nonlinear wave and Schrödinger equations on compact Lie groups and homogeneous spaces  

Microsoft Academic Search

We develop linear and nonlinear harmonic analysis on compact Lie groups and homogeneous spaces relevant for the theory of evolutionary Hamiltonian PDEs. A basic tool is the theory of the highest weight for irreducible representations of compact Lie groups. This theory provides an accurate description of the eigenvalues of the Laplace-Beltrami operator as well as the multiplication rules of its

Massimiliano Berti; Michela Procesi

2011-01-01

75

Immunocytochemical localization of prohormone convertases PC1 and PC2 in the mouse thyroid gland and respiratory tract.  

PubMed

We examined immunocytochemical localization of the prohormone convertases, PC1 and PC2, in the thyroid gland and respiratory tract of the adult mouse using the indirect enzyme- and immunogold-labeled antibody methods for light and electron microscopy, respectively. In the thyroid gland, PC1- and/or PC2-immunoreactive cells were cuboidal, scattered in the follicular epithelium and in the interfollicular spaces. When serial sections were immunostained with anti-calcitonin, anti-PC1, anti-calcitonin-gene-related-peptide (CGRP), and anti-PC2 sera, respectively, localization of both PC1 and PC2 was restricted to the calcitonin/CGRP-producing parafollicular cells. In the respiratory tract, only PC1 immunoreactivity was observed in the basal granulated neuroendocrine cells, which were scattered in the tracheal epithelium. Consecutive sections immunostained with anti-PC1 and anti-CGRP sera showed that a subpopulation of these PC1-immunoreactive cells contained CGRP. Double immunogold electron microscopy of the thyroid parafollicular cells revealed that calcitonin- and/or CGRP-immunopositive secretory granules were also labeled with both PC1 and PC2. These findings suggest that procalcitonin is proteolytically cleaved by PC2 alone or by PC2 together with PC1, and that the proCGRP is cleaved by PC1. PMID:12070269

Kurabuchi, Shingo; Tanaka, Shigeyasu

2002-07-01

76

A simple assay to study social behavior in Drosophila: measurement of social space within a group.  

PubMed

We have established a new simple behavioral paradigm in Drosophila melanogaster to determine how genes and the environment influence the behavior of flies within a social group. Specifically, we measure social space as the distance between two flies. The majority of Canton-s flies, regardless of their gender, are within two body lengths from each other. Their social experience affects this behavior, with social isolation reducing and mating enhancing social space respectively, in both males and females. Unlike several other social behaviors in the fly, including the formation of social groups themselves (a well-described behavior), social space does not require the perception of the previously identified aggregation pheromone cis-vaccenyl acetate. Conversely, performance of the assay in darkness or mutations in the eye pigmentation gene white increased social space. Our results establish a new assay for the genetic dissection of a fundamental mode of social interaction. PMID:22010812

Simon, A F; Chou, M-T; Salazar, E D; Nicholson, T; Saini, N; Metchev, S; Krantz, D E

2011-11-23

77

Modelling LLE and VLE of methanol + n-alkane series using GC-PC-SAFT with a group contribution k ij  

Microsoft Academic Search

The fluid phase diagrams (LLE and VLE) of methanol+n-alkane mixtures series (from C4 up to C16) were modelled using GC-PC-SAFT EOS (Tamouza et al., Fluid Phase Equilibria 222–223 (2004) 67–76) combined with a recent method for computing kij based on the London theory (NguyenHuynh et al., Industrial & Engineering Chemistry Research 47 (2008) 8847–8858). This latter method requires pure compound

M. Mourah; D. NguyenHuynh; J. P. Passarello; J. C. de Hemptinne; P. Tobaly

2010-01-01

78

The extended loop group: An infinite dimensional manifold associated with the loop space  

NASA Astrophysics Data System (ADS)

A set of coordinates in the non-parametric loop-space is introduced. We show that these coordinates transform under infinite dimensional linear representations of the diffeomorphism group. An extension of the group of loops in terms of these objects is proposed. The enlarged group behaves locally as an infinite dimensional Lie group. Ordinary loops form a subgroup of this group. The algebraic properties of this new mathematical structure are analyzed in detail. Applications of the formalism to field theory, quantum gravity and knot theory are considered.

di Bartolo, Cayetano; Gambini, Rodolfo; Griego, Jorge

1993-11-01

79

Investigation of catalytic characterization of two-dimensional molecular space with regular ammonium and pyridine groups.  

PubMed

Novel two-dimensional molecular space with regular pyridine groups layered pyridine-4-amidepropylsilica (PAPS) and pyridine-4-amidephenylsilica (PAPhS) were successfully synthesized through grafting pyridine groups in the layer structure of two-dimensional molecular space with regular ammonium groups layered aminopropylsilica (ATMS-DS) and layered aminophenylsilica (APhTMS-DS). The two-dimensional structures were kept after grafting reaction of pyridine groups in PAPS and PAPhS. The catalytic potentials of two-dimensional molecular space with regular ammonium and pyridine groups were investigated. The catalytic capability of APhTMS-DS, PAPS, and PAPhS was confirmed through Knoevenagel condensation reactions. Knoevenagel condensation of aromatic aldehydes with malononitrile was not observed in the presence of ATMS-DS. Otherwise, the lower yield of Knoevenagel condensation of higher active 2-chlorobenzaldehyde with malononitrile in the presence of APhTMS-DS, PAPS, and PAPhS indicated the potential of the two-dimensional molecular space with regular catalyst molecules on influencing catalysis processes utilizing the chemical and geometrical limits. PMID:19296641

Chen, Jianming; Yao, Ken; Shangguan, Wenfeng; Yuan, Jian

2009-05-19

80

Formation of P-C bond through reductive coupling between bridging phosphido and benzoquinolinate groups. Isolation of complexes of the Pt(II)/Pt(IV)/Pt(II) sequence.  

PubMed

The rational synthesis of dinuclear asymmetric phosphanido derivatives of palladium and platinum(II), [NBu(4)][(R(F))(2)M(?-PPh(2))(2)M'(?(2),N,C-C(13)H(8)N)] (R(F) = C(6)F(5); M = M' = Pt, 1; M = Pt, M' = Pd, 2; M = Pd, M' = Pt, 3; M = M' = Pd, 4), is described. Addition of I(2) to 1-4 gives complexes [(R(F))(2)M(II)(?-PPh(2))(?-I)Pd(II){PPh(2)(C(13)H(8)N)}] (M = M' = Pt, 6; M = Pt, M' = Pd, 7; M = M' = Pd, 8; M = Pd, M' = Pt 10) which contain the aminophosphane PPh(2)(C(13)H(8)N) ligand formed through a Ph(2)P/C^N reductive coupling on the mixed valence M(II)-M'(IV) [NBu(4)][(R(F))(2)M(II)(?-PPh(2))(2)M'(IV)(?(2),N,C- C(13)H(8)N)I(2)] complexes, which were identified for M(II) = Pd, M'(IV) = Pt (9), and isolated for M(II) = Pt, M'(IV) = Pt (5). Complex 5 showed an unusual dynamic behavior consisting in the exchange of two phenyl groups bonded to different P atoms, as well as a "through space" spin-spin coupling between ortho-F atoms of the pentafluorophenyl rings. PMID:23140340

Arias, Andersson; Forniés, Juan; Fortuño, Consuelo; Martín, Antonio; Latronico, Mario; Mastrorilli, Piero; Todisco, Stefano; Gallo, Vito

2012-11-09

81

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

Microsoft Academic Search

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

Walter F. Dankhoff; William P. Hope Jr.

1993-01-01

82

An introduction to data reduction: space-group determination, scaling and intensity statistics.  

PubMed

This paper presents an overview of how to run the CCP4 programs for data reduction (SCALA, POINTLESS and CTRUNCATE) through the CCP4 graphical interface ccp4i and points out some issues that need to be considered, together with a few examples. It covers determination of the point-group symmetry of the diffraction data (the Laue group), which is required for the subsequent scaling step, examination of systematic absences, which in many cases will allow inference of the space group, putting multiple data sets on a common indexing system when there are alternatives, the scaling step itself, which produces a large set of data-quality indicators, estimation of |F| from intensity and finally examination of intensity statistics to detect crystal pathologies such as twinning. An appendix outlines the scoring schemes used by the program POINTLESS to assign probabilities to possible Laue and space groups. PMID:21460446

Evans, Philip R

2011-03-18

83

An introduction to data reduction: space-group determination, scaling and intensity statistics  

PubMed Central

This paper presents an overview of how to run the CCP4 programs for data reduction (SCALA, POINTLESS and CTRUNCATE) through the CCP4 graphical interface ccp4i and points out some issues that need to be considered, together with a few examples. It covers determination of the point-group symmetry of the diffraction data (the Laue group), which is required for the subsequent scaling step, examination of systematic absences, which in many cases will allow inference of the space group, putting multiple data sets on a common indexing system when there are alternatives, the scaling step itself, which produces a large set of data-quality indicators, estimation of |F| from intensity and finally examination of intensity statistics to detect crystal pathologies such as twinning. An appendix outlines the scoring schemes used by the program POINTLESS to assign probabilities to possible Laue and space groups.

Evans, Philip R.

2011-01-01

84

Space and time: an impact of spatial separation, apparent motion, and perceptual grouping on TOJ performance.  

PubMed

This study explored the effects of spacing and objecthood (ie grouping based on closure) on temporal order judgment (TOJ) with displays that either involved successive onset of the target stimuli, resulting in apparent motion (experiments 1 and 2), or included simultaneous onset but successive shortening of the stimuli, and therefore did not result in apparent motion (experiment 3). We found a robust effect of spatial separation whose nature depended on whether or not the display allowed the emergence of illusory motion. Specifically, with apparent motion TOJ was best with the smallest spacing, but without it TOJ was worst with the smallest spacing. Moreover, overall accuracy was better with, than without, apparent motion. A small effect of objecthood--poorer TOJ performance when the elements formed an object--emerged only when spacing was not manipulated. These findings suggest that different mechanisms mediate temporal processing when we have access to motion information than when we do not. PMID:23964380

Baruch, Orit; Yeshurun, Yaffa; Shore, David I

2013-01-01

85

Experiences of Young Bisexual Women in Lesbian\\/Bisexual Groups on MySpace  

Microsoft Academic Search

This exploratory study examined Topic threads in Lesbian\\/Bisexual Groups on MySpace to examine how young biwomen self-identify in online exchanges with other bisexuals and lesbians, as well as what attitudes and beliefs about bisexuality emerge from those exchanges. Four Topic threads from three Groups suggested that young biwomen use social networking sites to connect with others and create inclusive communities

M. Sue Crowley

2010-01-01

86

Real space renormalization group and totalitarian paradox of majority rule voting  

Microsoft Academic Search

The effect of majority rule voting in hierarchical structures is studied using the basic concepts from real space renormalization group. It shows in particular that a huge majority can be self-eliminated while climbing up the hierarchy levels. This majority democratic self-elimination articulates around the existence of fixed points in the voting flow. An unstable fixed point determines the critical threshold

Serge Galam

2000-01-01

87

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...

88

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

89

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

90

Semisimple Banach algebras generated by compact groups of operators on a Banach space  

NASA Astrophysics Data System (ADS)

We prove that if [tau] is a strongly continuous representation of a compact group G on a Banach space X, then the weakly closed Banach algebra generated by the Fourier transforms with [mu][set membership, variant]M(G) is a semisimple Banach algebra.

Gale, Jose E.; Villena, Armando R.

2007-01-01

91

Unusual catalytic effect of the two-dimensional molecular space with regular triphenylphosphine groups.  

PubMed

A novel organic-inorganic hybrid 2D molecular space with regular triphenylphosphine groups (triphenylphosphineamidephenylsilica, PPh(3)APhS) was successfully synthesized through grafting triphenylphosphine groups in the 2D structure of layered aminophenylsilica dodecyl sulfate (APhTMS-DS), which was developed in our previous research, with regular ammonium groups. The 2D structures were kept after the grafting reaction of triphenylphosphine groups in PPh(3)APhS. The catalytic potentials of 2D molecular space with regular triphenylphosphine groups were investigated. An unusual catalytic effect was found in a carbon-phosphorus ylide reaction. The PPh(3)-catalyzed reaction of modified allylic compounds, including bromides and chlorides with tropone yielded a [3 + 6] annulation product. However, an unusual [8 + 3] cycloadduct was obtained in the reaction of modified allylic compounds, including bromides and chlorides with tropone catalyzed by PPh(3)APhS. Otherwise, the stable catalytic intermediate was successfully separated, and the reaction activity of the catalytic intermediate was confirmed in the reaction of modified allylic compounds with tropone catalyzed by PPh(3)APhS. This research is the first successful example of directly influencing catalytic reaction processes and product structures by utilizing the chemical and geometrical limits of 2D molecular spaces with regular catalyst molecules and affords a novel method for controlling catalytic reaction processes and catalyst design. PMID:21905651

Chen, Chen; Shao, Xue; Yao, Ken; Yuan, Jian; Shangguan, Wenfeng; Kawaguchi, Toshikazu; Shimazu, Katsuaki

2011-09-09

92

Space-time versus world-sheet renormalization group equation in string theory  

NASA Astrophysics Data System (ADS)

We discuss the relation between space-time renormalization group equation for closed string field theory and world-sheet renormalization group equation for first-quantized strings. Restricting our attention to massless states we argue that there is a one-to-one correspondence between the fixed point solutions of the two renormalization group equations. In particular, we show how to extract the Fischler-Susskind mechanism from the string field theory equation in the case of the bosonic string. Supported in part by the Danish Natural Science Research Council and the SARC Foundation.

Brustein, Ram; Roland, Kaj

1992-03-01

93

Bayesian probability theory applied to the space group problem in powder diffraction  

NASA Astrophysics Data System (ADS)

Crystal structure determination from powder diffraction data has become a viable option for molecules with less than 50 non-hydrogen atoms in the asymmetric unit and this includes the majority of compounds of pharmaceutical interest. The solution of crystal structures, including space group determination, is more challenging from powder diffraction data than from single crystal diffraction data. Here, it will be demonstrated how a Bayesian probability analysis of this problem has helped to provide a new algorithm for the determination of the space group symmetry of a crystal from powder diffraction data. Specifically, the relative probabilities of different extinction symbols are accessed within a particular crystal system. Examples will be presented to illustrate this approach.

Markvardsen, A. J.

2004-11-01

94

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

95

Realization of vector fields for quantum groups as pseudodifferential operators on quantum spaces  

SciTech Connect

The vector fields of the quantum Lie algebra are described for the quantum groups GL{sub q}(n), SL{sub q}(N) and SO{sub q}(N) as pseudodifferential operators on the linear quantum spaces covariant under the corresponding quantum group. Their expressions are simple and compact. It is pointed out that these vector fields satisfy certain characteristic polynomial identities. The real forms SU{sub q}(N) and SO{sub q}(N,R) are discussed in detail.

Chu, Chong-Sun; Zumino, B.

1995-01-24

96

Biomimicry 1: PC.  

PubMed

The surface properties of stents can be modified by coating them, for example with a polymer. Phosphorylcoline (PC) is the major component of the outer layer of the cell membrane. The haemo- and biocompatibility of a PC-containing polymer is thus based on biomimicry, and has been confirmed by several experiments showing much reduced thrombogenicity of PC-coated surfaces, and porcine coronary artery implants showing no sign of adverse effect. Clinical experience with the PC-coated BiodivYsio appears favourable. The PC coating can be tailored for take up and controlled elution of various drugs for stent-based local delivery, a property which is being actively explored. PMID:10406685

Cumberland, D C; Gunn, J; Malik, N; Holt, C M

97

A summary of activities of the US\\/Soviet-Russian joint working group on space biology and medicine  

Microsoft Academic Search

The very foundation of cooperation between the United States (US) and Russia (former Soviet Union) in space exploration is a direct result of the mutual desire for scientific understanding and the creation of a collaborative mechanism—the Joint Working Group (JWG) on Space Biology and Medicine. From the dawn of the space age, it has been the quest of humankind to

Charles R. Doarn; Arnauld E. Nicogossian; Anatoly I. Grigoriev; Galina Tverskaya; Oleg I. Orlov; Eugene A. Ilyin; Kenneth A. Souza

2010-01-01

98

Testing the accuracy of redshift-space group-finding algorithms  

NASA Astrophysics Data System (ADS)

Using simulated redshift surveys generated from a high-resolution N-body cosmological structure simulation, we study algorithms used to identify groups of galaxies in redshift space. Two algorithms are investigated; both are friends-of-friends schemes with variable linking lengths in the radial and transverse dimenisons. The chief difference between the algorithms is in the redshift linking length. The algorithm proposed by Huchra & Geller (1982) uses a generous linking length designed to find 'fingers of god,' while that of Nolthenius & White (1987) uses a smaller linking length to minimize contamination by projection. We find that neither of the algorithms studied is intrinsically superior to the other; rather, the ideal algorithm as well as the ideal algorithm parameters depends on the purpose for which groups are to be studied. The Huchra & Geller algorithm misses few real groups, at the cost of including some spurious groups and members, while the Nolthenius & White algorithm misses high velocity dispersion groups and members but is less likely to include interlopers in its group assignments. Adjusting the parameters of either algorithm results in a trade-off between group accuracy and completeness. In a companion paper we investigate the accuracy of virial mass estimates and clustering properties of groups identified using these algorithms.

Frederic, James J.

1995-04-01

99

Oxidative stability of liposomes prepared from soybean PC, chicken egg PC, and salmon egg PC.  

PubMed

The oxidative stability of phosphatidylcholines (PCs) from soybean, chicken egg, and salmon egg in liposomes was compared with that in aqueous micelles. When each PC was oxidized in aqueous micelles, salmon egg PC was the most oxidatively stable, followed by chicken egg PC and soybean PC, however, no significant difference in the oxidative stability was apparent between chicken egg PC and salmon egg PC in liposomes. The main molecular species of soybean PC was 1,2-dilinoleoyl-PC, while most of the PUFAs in chicken egg PC and salmon egg PC were not esterified at the sn-1 position but at the sn-2 position. Therefore, it is suggested that the oxidative stability of PC liposomes would be strongly influenced by the positional distribution of PUFAs in the PC molecule. Further studies on the oxidation of PC liposomes showed that chicken egg albumin and soybean protein protected PC bilayers against attack by free radicals generated in the aqueous phase. PMID:9362120

Nara, E; Miyashita, K; Ota, T

1997-10-01

100

IERS Working group on Combination of Space Geodetic Techniques at the Observation Level (COL)  

NASA Astrophysics Data System (ADS)

The different space geodetic techniques have different strengths and weaknesses for recovering geodetic parameters. This makes their combination useful. However they may have some systematic behaviour which can be detected and removed at the observation level. In order to review the interest in combining techniques at this level, a Working Group at the Combination Level (WG COL) was set up in the course of 2009 in the frame of the International Earth Rotation and Reference Systems Service (IERS). A major task of the WG COL is to study methods and advantages of combining space geodetic techniques (DORIS, GNSS, SLR, VLBI), searching for an optimal strategy to solve for geodetic parameters. The first action of the Working Group was to organize an inter-comparison benchmark campaign to serve as a test. The period chosen is from August 10 to August 30, 2008. It includes the intensive CONT08 VLBI period. The combination analyses are based on weekly or daily combined SINEX files which contain normal equations of station coordinates, Earth Orientation Parameters from all space geodetic techniques, tropospheric parameters for GNSS, DORIS and VLBI techniques and quasar coordinates for the VLBI technique. We will present the objectives and strategy of multi-technique combination, establishing conventions and some results already achieved.

Richard, J.-Y.; Biancale, R.; Bizouard, C.; Deleflie, F.; Gambis, G.; Koenig, R.; Loyer, S.; Sciaretta, C.; Seitz, M.; Spicakova, H.; Springer, T.; Thaller, D.

2012-04-01

101

Processor-Group Aware Runtime Support for Shared-and Global-Address Space Models  

SciTech Connect

Exploiting multilevel parallelism using processor groups is becoming increasingly important for programming on high-end systems. This paper describes a group-aware run-time support for shared-/global- address space programming models. The current effort has been undertaken in the context of the Aggregate Remote Memory Copy Interface (ARMCI) [5], a portable runtime system used as a communication layer for Global Arrays [6], Co-Array Fortran (CAF) [9], GPSHMEM [10], Co-Array Python [11], and also end-user applications. The paper describes the management of shared memory, integration of shared memory communication and RDMA on clusters with SMP nodes, and registration. These are all required for efficient multi- method and multi-protocol communication on modern systems. Focus is placed on techniques for supporting process groups while maximizing communication performance and efficiently managing global memory system-wide.

Krishnan, Manoj Kumar; Tipparaju, Vinod; Palmer, Bruce; Nieplocha, Jarek

2004-12-07

102

Opechowski-Guccione-like symbols labelling magnetic space groups independent of tabulated (0, 0, 0)+ sets.  

PubMed

For the magnetic space-group types with a black and white lattice two sets of symbols have been proposed: the BNS symbols [Belov et al. (1957). Sov. Phys. Crystallogr. 2, 311-322] and the OG symbols [Opechowski & Guccione (1965). Magnetism, edited by G. T. Rado & H. Suhl, Vol. II, Part A, pp. 105-165. New York: Academic Press]. Whereas generators of the group can be read off the BNS symbol, International Tables for X-ray Crystallography (1952) must be consulted to interpret the OG symbols. In the cases where the black and white lattice is centred, it is shown how the OG symbols can be modified so that generators of the group can be deduced directly from the symbol. PMID:20404436

Grimmer, Hans

2010-03-26

103

PC-SPES (PDQ)  

MedlinePLUS

... 2011/2012 Update Overview PC-SPES is a mixture of 8 herbs that was sold as a ... SPES, prescription medicines that were found in the mixture, or both (see Question 5 ). Clinical trials suggested ...

104

Pressure and equilibrium measures for actions of amenable groups on the space of configurations  

SciTech Connect

The model of statistical physics on a countable amenable group G is considered. For the natural action of G on the space of configurations S{sup G}, |S|<{infinity}, and for any closed invariant set X subset of S{sup G} we prove that there exists pressure which corresponds to a potential with finite norm on X (in the sense of the limit with respect to any Foelner sequence of sets in G). The existence of an equilibrium measure is established. Bibliography: 8 titles.

Bufetov, Aleksei I [M. V. Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow (Russian Federation)

2011-03-31

105

Regularity properties and pathologies of position-space renormalization-group transformations  

NASA Astrophysics Data System (ADS)

We consider the conceptual foundations of the renormalization-group (RG) formalism. We show that the RG map, defined on a suitable space of interactions, is always single-valued and Lipschitz continuous on its domain of definition. This rules out a recently proposed scenario for the RG description of first-order phase transitions. On the other hand, we prove in several cases that near a first-order phase transition the renormalized measure is not a Gibbs measure for any reasonable interaction. It follows that the conventional RG description of first-order transitions is not universally valid. Speaker at the conference.

van Enter, Aernout C. D.; Fernández, Roberto; Sokal, Alan D.

1991-05-01

106

Crystallization of the Focal Adhesion Kinase Targeting (FAT) Domain in a Primitive Orthorhombic Space Group  

SciTech Connect

X-ray diffraction data from the targeting (FAT) domain of focal adhesion kinase (FAK) were collected from a single crystal that diffracted to 1.99 Angstroms resolution and reduced to the primitive orthorhombic lattice. A single molecule was predicted to be present in the asymmetric unit based on the Matthews coefficient. The data were phased using molecular-replacement methods using an existing model of the FAK FAT domain. All structures of human focal adhesion kinase FAT domains solved to date have been solved in a C-centered orthorhombic space group.

Magis,A.; Bailey, K.; Kurenova, E.; Hernandez Prada, J.; Cance, W.; Ostrov, D.

2008-01-01

107

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.

Perkins, Dexter

108

Electron precession microdiffraction as a useful tool for the identification of the space group.  

PubMed

The possible space groups of a crystal can be identified from a few zone axis microdiffraction patterns provided the position (and not the intensity) of the reflections on the patterns is taken into account. The method is based on the observation of the shifts and the periodicity differences between the reflections located in the first-order Laue zone (FOLZ) with respect to the ones located in the zero-order Laue zone (ZOLZ). Electron precession microdiffraction patterns display more reflections in the ZOLZ and in the FOLZ than in the conventional microdiffraction patterns and this number increases with the precession angle. It is shown, from the TiAl example given in the present study, that this interesting feature brings a strong beneficial effect for the identification of the possible space groups since it becomes very easy to identify unambiguously the FOLZ/ZOLZ shifts and periodicity differences. In addition, the diffracted intensity on the precession patterns is the integrated intensity and this intensity can also be used to identify the Laue class. PMID:17845710

Morniroli, J-P; Redjaimia, A

2007-08-01

109

Space group symmetry applied to SCF calculations with periodic boundary conditions and Gaussian orbitals  

NASA Astrophysics Data System (ADS)

Space group symmetry is exploited and implemented in density functional calculations of extended systems with periodic boundary conditions. Our scheme for reducing the number of two-electron integrals employs the entire set of operations of the space group, including glide plains and screw axes. Speedups observed for the Fock matrix formation in simple 3D systems range from 2X to 9X for the near field Coulomb part and from 3X to 8X for the Hartree-Fock-type exchange, the slowest steps of the procedure, thus leading to a substantial reduction of the computational time. The relatively small speedup factors in special cases are attributed to the highly symmetric positions atoms occupy in crystals, including the ones tested here, as well as to the choice of the smallest possible unit cells. For quasi-1D systems with most atoms staying invariant only under identity, the speedup factors often exceed one order of magnitude reaching almost 70X (near-field Coulomb) and 57X (HFx) for the largest tested (16,7) single-walled nanotube with 278 symmetry operations.

Rusakov, Alexander A.; Frisch, Michael J.; Scuseria, Gustavo E.

2013-09-01

110

Space group symmetry applied to SCF calculations with periodic boundary conditions and Gaussian orbitals.  

PubMed

Space group symmetry is exploited and implemented in density functional calculations of extended systems with periodic boundary conditions. Our scheme for reducing the number of two-electron integrals employs the entire set of operations of the space group, including glide plains and screw axes. Speedups observed for the Fock matrix formation in simple 3D systems range from 2X to 9X for the near field Coulomb part and from 3X to 8X for the Hartree-Fock-type exchange, the slowest steps of the procedure, thus leading to a substantial reduction of the computational time. The relatively small speedup factors in special cases are attributed to the highly symmetric positions atoms occupy in crystals, including the ones tested here, as well as to the choice of the smallest possible unit cells. For quasi-1D systems with most atoms staying invariant only under identity, the speedup factors often exceed one order of magnitude reaching almost 70X (near-field Coulomb) and 57X (HFx) for the largest tested (16,7) single-walled nanotube with 278 symmetry operations. PMID:24070282

Rusakov, Alexander A; Frisch, Michael J; Scuseria, Gustavo E

2013-09-21

111

Finite-Dimensional Approximations of Operators in the Hilbert Spaces of Functions on Locally Compact Abelian Groups  

Microsoft Academic Search

A new approach to the approximation of operators in the Hilbert space of functions on a locally compact Abelian (LCA) group is developed. This approach is based on sampling the symbols of such operators. To choose the points for sampling, we use the approximations of LCA groups by finite groups, which were introduced and investigated by Gordon. In the case

S. Albeverio; E. I. Gordon; A. Yu. Khrennikov

2000-01-01

112

Public opinion and interest group positions on open-space issues in Albuquerque, New Mexico, USA: Implications for resource management  

NASA Astrophysics Data System (ADS)

The purpose of this research was to elicit and compare the open-space preferences of citizens and openspace experts in Albuquerque, New Mexico, USA. A randomly selected sample of 492 citizens and 35 open-space experts participated in a telephone survey during May 5 18, 1986. The following hypothesis was tested and used as a guideline for the study: HO1: There is no significant difference between respondents' status and preference for open space in Albuquerque, New Mexico. The hypothesis was rejected. Findings confirmed respondents' status affected preference for open space. Of the eight issues on which the citizen and expert groups were compared, five recorded significant differences in response profiles. The open-space expert group was significantly more supportive of using open space to accommodate offroad vehicle facilities, wildlife preserves, a citywide recreational trail, and a trail system along the arroyos and city ditches. The citizen sample was significantly more supportive of using open space to accommodate overnight camping facilities. Both groups equally supported using open space to accommodate an outdoor amphitheater, outdoor education facilities, and rafting, kayaking, and canoeing facilities. The finding indicated that expert preferences did not represent an aggregate of citizen preferences for managing open-space resources. Understanding both expert and citizen positions will facilitate decision-making processes and help resolve environmental disputes.

Tannery, Thomas Allan

1987-07-01

113

Application of the renormalization group to the calculation of the vacuum decay rate in flat and curved space-time  

SciTech Connect

I show that an application of renormalization group arguments may lead to significant corrections to the vacuum decay rate for phase transitions in flat and curved space-time. It can also give some information regarding its dependence on the parameters of the theory, including the cosmological constant in the case of decay in curved space-time.

Metaxas, Dimitrios [Department of Physics, National Technical University of Athens, Zografou Campus, 15780 Athens (Greece)

2007-02-15

114

Systematic prediction of new ferroelectrics in space group R3. I.  

PubMed

Release 2005/1 of the Inorganic Crystal Structure Database contains 158 entries under the space group R3. The first 81 together with 15 related entries include 52 different structure types, 10 of which represent families that have two or more isostructural members. There are 18 types that satisfy the structural criteria for ferroelectricity with a confidence level that necessarily depends upon the reliability of each structural determination. Among them, (LiTaO3)9.Ta2O5 and the CsCd(NO2) family are known ferroelectrics. The remaining 16 include the high-intensity higher-order harmonic generator II-BaB2O4, not previously recognized as ferroelectric. The other predicted ferroelectrics are Te(OH)6.NaF, the MgSO3.6H2O family, Li3P3O9.3H2O, SeNbF9, Al2(H2PO4)3PO4.6H2O, [Cr(OCN2H4)6].[(Co(NH3)2(NO2)4]3.(H2O)(1.5)], NaZnBr3.5H2O, III-Ag3SI, Tl2S, the Ba3Yb4O9 family, the Fe(10.7)Ru(1.3)As5 family, Sr17Ta10S42, Pb8Sb3 and the Sc7I12C family. Six structures reported in the space group R3 most likely exhibit mirror symmetry, with three experimental confirmations. The other 19 structures are most likely nonpolar, with six experimental confirmations. The capacity for physical property prediction by the remaining ten structures is shown to be in doubt. Thus, 46% of the present 52 inorganic structure types initially determined in the space group R3 and 35% of those currently assigned to R3 more likely exhibit an additional inversion center, mirror or glide plane, strongly exceeding the recently reported error rate of approximately 11% in organic structures. PMID:16434790

Abrahams, S C

2006-01-17

115

Exploring for 3D photonic bandgap structures in the 11 f.c.c. space groups  

NASA Astrophysics Data System (ADS)

The promise of photonic crystals and their potential applications has attracted considerable attention towards the establishment of periodic dielectric structures that in addition to possessing robust complete bandgaps, can be easily fabricated with current techniques. A number of theoretical structures have been proposed. To date, the best complete photonic bandgap structure is that of diamond networks having Fd3m symmetry (2-3 gap). The only other known complete bandgap in a face-centred-cubic (f.c.c.) lattice structure is that of air spheres in a dielectric matrix (8-9 gap; the so called 'inverse-opal' structure). Importantly, there is no systematic approach to discovering champion photonic crystal structures. Here we propose a level-set approach based on crystallography to systematically examine for photonic bandgap structures and illustrate this approach by applying it to the 11 f.c.c. groups. This approach gives us an insight into the effects of symmetry and connectivity. We classify the F-space groups into four fundamental geometries on the basis of the connectivity of high-symmetry Wyckoff sites. Three of the fundamental geometries studied display complete bandgaps-including two: the F-RD structure with Fm'3 m symmetry and a group 216 structure with F 4'3m symmetry that have not been reported previously. By using this systematic approach we were able to open gaps between the 2-3, 5-6 and 8-9 bands in the f.c.c. systems.

Maldovan, Martin; Ullal, Chaitanya K.; Carter, W. Craig; Thomas, Edwin L.

2003-10-01

116

Tabulation of irreducible representations of the crystallographic space groups and their superspace extensions.  

PubMed

New tables of irreducible representations (IRs) are introduced for the 230 crystallographic space groups (SGs) in three-dimensional space, at both special and non-special k vectors, and for their extensions to (3 + d)-dimensional superspace (`superspace-extended SGs' or SSESGs). Neither a tabulation of SG IR matrices for non-special k vectors nor a tabulation of SSESG IR matrices for d > 1 have been previously published. These tabulations are made possible by a new form in which the IR matrices of SGs are separated as a product of a translation part T and a point-operation part P, and where the IR matrices of SSESGs are separated as a product of a phase-shift part Q and a point-operation part P(s). Both T and Q have a simple prescribed form that does not need to be tabulated. Also, the new IR matrices are in a convenient block form which allows one to see by inspection which parts of the matrices and the associated order parameters belong to which arm of the star of k. In addition to complex IR matrices, real physically irreducible representation (PIR) matrices are tabulated. The new IR and PIR tables are available on the ISO-IR website (http://stokes.byu.edu/iso/irtables.php) in both convenient human-readable and computer-readable forms. PMID:23778095

Stokes, Harold T; Campbell, Branton J; Cordes, Ryan

2013-05-08

117

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.

118

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

119

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]|[Lawrence Berkeley National Lab., CA (United States)

1997-05-23

120

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.

121

Sex of preceding child and birth spacing among Nigerian ethnic groups.  

PubMed

In seeking for more effective ways of fertility control and improvement of maternal and child health through birth spacing in a predominantly patrilineal society like Nigeria, this study explores how the sex of a previous child affects birth interval among ethnic groups, controlling for demographic and socioeconomic variables. The study utilized birth history data from the 2008 Nigeria Demographic and Health Survey. The findings showed that the effect of sex of prior births on the birth interval is slightly significant among the Igbo and the Southern minorities, who tend to desire to have a male child sooner if preceding births were female. Among all the ethnic groups, women who are yet to meet their ideal sex preference have a shorter birth interval than those who have. Apart from the evident sex preferences, these results suggest that Nigerian parents also undertake sex balancing among their children. There is a consistent and strong relationship between the survival of a child and subsequent birth interval, which suggest that women have a short birth interval, and hence a large family size, because they are not certain that their children would survive. PMID:22590895

Fayehun, O A; Omololu, O O; Isiugo-Abanihe, U C

2011-06-01

122

Lost in Transmission: Using Study Groups to Provide Space for Creativity and Reflexivity in an Instrumentalist University Environment  

ERIC Educational Resources Information Center

Since independent study groups can be important in providing spaces for students in creative disciplines to develop a critically reflexive approach to their creative practice, tutors in an Australian university introduced independent group learning to students studying in creative disciplines. However, student responses to the experience of…

Pearce, Jane; Crouch, Christopher

2010-01-01

123

A Hubble Space Telescope Treasury Study of Star-forming Regions in the Local Group. II. Young Stellar Populations in M31  

NASA Astrophysics Data System (ADS)

We studied the young stellar populations of 22 star-forming regions in the Andromeda galaxy (M31), with Hubble Space Telescope (HST) multi-band imaging from far-UV to I. The regions were selected from Galaxy Evolution Explorer (GALEX) wide-field far-UV imaging; they sample different environments and galactocentric distances from 6 to 22 kpc. They were imaged with 30 HST fields (360 distinct images, in six bandpasses), with a pixel scale of 0.38 pc projected on the sky, at the distance of M31. This study is part of HST treasury survey program HST-GO-11079, which includes star-forming regions in eight Local Group galaxies. We provide a merged catalog of six-band stellar photometry in the 30 M31 fields, containing 118,036 sources brighter than V and B ~ 23 mag. Each HST field covers about 0.3 kpc2 in M31, and contains up to ~7000 stars, of which the number varies by a factor of >7 among the target regions; a large fraction of the sample are hot massive stars, due to our choice of filters and exposures. We derived stellar physical parameters and interstellar extinction for individual sources by spectral energy distribution analysis with model-atmosphere colors, and used the results to infer ages, massive stars content, and extinction of the star-forming regions. Reddening is up to E(B - V) <~ 0.6 mag in some OB associations, and lowest in the outermost regions (average of lsim0.12 mag in OB184 at 21.9 kpc). We examined the spatial distribution (clustering) of the hot massive stars, and defined OB associations on various spatial scales from compact to wider, more spread out ones. A hierarchical structuring is observed, with small compact groups arranged within large complexes. Their areas vary from less than 10 to 105 pc2, and masses are up to ?105 M ?, in the scales sampled by our analysis. Their cumulative mass distribution follows a power law, at least in part of the sampled regime. Hot-star counts in the young regions compare very well with integrated measurements of UV flux from GALEX.

Bianchi, Luciana; Efremova, Boryana; Hodge, Paul; Kang, Yongbeom

2012-11-01

124

On the space group of the double perovskite Ba{sub 2}PrIrO{sub 6}  

SciTech Connect

The structure of the double perovskite Ba{sub 2}PrIrO{sub 6} has been re-examined by profile analysis of X-ray diffraction data. It has been shown that neither the monoclinic P2{sub 1}/n nor the tetragonal P4/mnc space group correctly describes its structure. Ba{sub 2}PrIrO{sub 6} has cubic symmetry, space group Fm3-bar m, cell parameter a=8.40135(6)A. In agreement with earlier observations, Ba{sub 2}PrIrO{sub 6} is an ordered perovskite containing the valence pair Pr(IV)/Ir(IV)

Fu, W.T. [Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands)]. E-mail: w.fu@chem.leidenuniv.nl; IJdo, D.J.W. [Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands)

2005-04-15

125

On the perturbation of the group generalized inverse for a class of bounded operators in Banach spaces  

NASA Astrophysics Data System (ADS)

Given a bounded operator A on a Banach space X with Drazin inverse AD and index r, we study the class of group invertible bounded operators B such that I+AD(B-A) is invertible and . We show that they can be written with respect to the decomposition as a matrix operator, , where B1 and are invertible. Several characterizations of the perturbed operators are established, extending matrix results. We analyze the perturbation of the Drazin inverse and we provide explicit upper bounds of ||B#-AD|| and ||BB#-ADA||. We obtain a result on the continuity of the group inverse for operators on Banach spaces.

Castro-González, N.; Vélez-Cerrada, J. Y.

2008-05-01

126

The Proprotein Convertase PC7  

PubMed Central

The zymogen activation mechanism and physiological functions of the most ancient and highly conserved basic amino acid-specific proprotein convertase 7 (PC7) are not known. Herein, we characterized the biosynthesis, subcellular localization, and trafficking of the membrane-bound full-length rat and human PC7. The prosegment of PC7 is primarily secreted alone as a non-inhibitory protein via the conventional, Golgi-dependent, secretory pathway. Mature PC7 is partially sulfated and thus reaches the cell surface via the conventional route. However, a fraction of PC7 reaches the cell surface through a brefeldin A- and COPII-independent unconventional secretory pathway. The latter trafficking may explain the rapid (<10 min) transit of a fraction of PC7 from the ER to the cell surface. Electron microscopy further confirmed the localization of PC7 to the cell surface of HEK293 cells. Within the cytosolic tail, only two cysteines (Cys699 and Cys704) are palmitoylated, but this modification does not affect the choice of trafficking pathway. Swapping the transmembrane-cytosolic tail (TMCT) sequences of the convertases Furin and PC7 revealed that PC7TMCT-Furin is much more sulfated and hence traffics more efficiently through the conventional secretory pathway. In contrast, the FurinTMCT-PC7 is no longer sulfated and thus reaches the cell surface by the unconventional pathway. Because trafficking of PC7CT-Furin and FurinCT-PC7 resemble their wild type counterparts, we deduce that the transmembrane domain of PC7 regulates the sorting of PC7 toward the unconventional secretory pathway. In conclusion, PC7 is distinct from other proprotein convertases in its zymogen activation, subcellular localization, and trafficking.

Rousselet, Estelle; Benjannet, Suzanne; Hamelin, Josee; Canuel, Maryssa; Seidah, Nabil G.

2011-01-01

127

Doubly special relativity in position space starting from the conformal group  

Microsoft Academic Search

We propose version of doubly special relativity theory starting from position space. The version is based on deformation of ordinary Lorentz transformations due to the special conformal transformation. There is unique deformation which does not modify rotations. In contrast to the Fock–Lorentz realization (as well as to recent position-space proposals), maximum signal velocity is position (and observer) independent scale in

A. A. Deriglazov

2004-01-01

128

Predicting stable stoichiometries of compounds via evolutionary global space-group optimization  

NASA Astrophysics Data System (ADS)

Whereas the Daltonian atom-to-atom ratios in ordinary molecules are well understood via the traditional theory of valence, the naturally occurring stoichiometries in intermetallic compounds ApBq , as revealed by phase-diagram compilations, are often surprising. Even equal-valence elements A and B give rise to unequal (p,q) stoichiometries, e.g., the 1:2, 2:1, and 3:1 ratios in AlpScq . Moreover, sometimes different stoichiometries are associated with different lattice types and hence rather different physical properties. Here, we extend the fixed-composition global space-group optimization (GSGO) approach used to predict, via density-functional calculations, fixed-composition lattice types [G. Trimarchi and A. Zunger, J. Phys.: Condens. Matter 20, 295212 (2008)] to identify simultaneously all the minimum-energy lattice types throughout the composition range. Starting from randomly selected lattice vectors, atomic positions and stoichiometries, we construct the T=0 “convex hull” of energy vs composition. Rather than repeat a set of GSGO searches over a fixed list of stoichiometries, we minimize the distance to the convex hull. This approach is far more efficient than the former one as a single evolutionary search sequence simultaneously identifies the lowest-energy structures at each composition and among these it selects those that are ground states. For Al-Sc we correctly identify the stable stoichiometries and relative structure types: AlSc2-B82 , AlSc-B2, and Al2Sc-C15 in the Nat=6 periodic cells, and Al2Sc6-D019 , AlSc-B2, and Al3Sc-L10 in the Nat=8 periodic cells. This extended evolutionary GSGO algorithm represents a step toward a fully ab initio materials synthesis, where compounds are predicted starting from sole knowledge of the chemical species of the constituents.

Trimarchi, Giancarlo; Freeman, Arthur J.; Zunger, Alex

2009-09-01

129

PC Scene Generation  

NASA Astrophysics Data System (ADS)

AMRDEC has successfully tested hardware and software for Real-Time Scene Generation for IR and SAL Sensors on COTS PC based hardware and video cards. AMRDEC personnel worked with nVidia and Concurrent Computer Corporation to develop a Scene Generation system capable of frame rates of at least 120Hz while frame locked to an external source (such as a missile seeker) with no dropped frames. Latency measurements and image validation were performed using COTS and in-house developed hardware and software. Software for the Scene Generation system was developed using OpenSceneGraph.

Buford, James A., Jr.; Cosby, David; Bunfield, Dennis H.; Mayhall, Anthony J.; Trimble, Darian E.

2007-04-01

130

Real-space scaling methods applied to the one-dimensional extended Hubbard model. I. The real-space renormalization-group method  

Microsoft Academic Search

The real-space renormalization-group method is applied to the one-dimensional extended Hubbard model. It is shown that in the half-filled-band case, the phase diagram consists of two phases and that the transition from the spin-ordered phase to the charge-ordered phase is continuous, a result which differs from that obtained previously from the broken-symmetry Hartree-Fock approximation.

B. Fourcade; G. Spronken

1984-01-01

131

Group vector space method for estimating enthalpy of vaporization of organic compounds at the normal boiling point.  

PubMed

The specific position of a group in the molecule has been considered, and a group vector space method for estimating enthalpy of vaporization at the normal boiling point of organic compounds has been developed. Expression for enthalpy of vaporization Delta(vap)H(T(b)) has been established and numerical values of relative group parameters obtained. The average percent deviation of estimation of Delta(vap)H(T(b)) is 1.16, which show that the present method demonstrates significant improvement in applicability to predict the enthalpy of vaporization at the normal boiling point, compared the conventional group methods. PMID:15272851

Wenying, Wei; Jinyu, Han; Wen, Xu

132

Group-Theoretical Approach to Extended Conformal Supersymmetry: Functional Space Realizations and Invariant Differential Operators.  

National Technical Information Service (NTIS)

We give function space realizations of all representations of the conformal superalgebra su(2,2/N) and of the corresponding supergroup induced from irreducible finite-dimensional Lorentz and SU(N) representations realized without spin and isospin indices....

V. K. Dobrev V. B. Petkova

1985-01-01

133

Pedagogical Use of Tablet PC for Active and Collaborative Learning  

Microsoft Academic Search

In this paper we present our experience using tablet PC to support the pedagogical needs of the engineering classroom as well as typical engineering group collaborative environments. We applied this novel active and collaborative learning framework to undergraduate students from a fundamental database course in order to analyze the role of pedagogical use of tablet PC. Then, this educational test

O. M. Bonastre; A. P. Benavent; F. N. Belmonte

2006-01-01

134

Structure-dependent exchange in the organic magnets Cu(II)Pc and Mn(II)Pc  

NASA Astrophysics Data System (ADS)

We study exchange couplings in the organic magnets copper(II) phthalocyanine [Cu(II)Pc] and manganese(II) phthalocyanine [Mn(II)Pc] by a combination of Green’s function perturbation theory and ab initio density-functional theory (DFT). Based on the indirect exchange model, our perturbation-theory calculation of Cu(II)Pc qualitatively agrees with the experimental observations. DFT calculations performed on Cu(II)Pc dimer show a very good quantitative agreement with exchange couplings that our theoretical group extracts by using a global fitting for the magnetization measurements to a spin- (1)/(2) Bonner-Fisher model. These two methods give us remarkably consistent trends for the exchange couplings in Cu(II)Pc when changing the stacking angles. The situation is more complex for Mn(II)Pc owing to the competition between superexchange and indirect exchange.

Wu, Wei; Kerridge, A.; Harker, A. H.; Fisher, A. J.

2008-05-01

135

Conditions for the Nontriviality of the Hilbert Space of a Holomorphically Induced Representation of a Solvable Lie Group  

NASA Astrophysics Data System (ADS)

The notion of holomorphically induced representation is a generalization of the concept of representation induced by a representation of a subgroup. It permitted Kostant and Auslander to give a classification of irreducible unitary representations of solvable Lie groups. A holomorphically induced representation is constructed in a function space on the group, where the functions satisfy a number of algebraic conditions and lie in some L^2-space. It may happen that some nontrivial functions satisfy the algebraic conditions but none of them lie in L^2. In this paper a necessary and sufficient condition that this not occur when the Lie group under consideration is solvable is proved. The condition involves the Lie algebra and the parameters appearing in the definition of the representation. Bibliography: 10 titles.

Za?cev, A. A.

1981-04-01

136

A summary of activities of the US/Soviet-Russian joint working group on space biology and medicine  

NASA Astrophysics Data System (ADS)

The very foundation of cooperation between the United States (US) and Russia (former Soviet Union) in space exploration is a direct result of the mutual desire for scientific understanding and the creation of a collaborative mechanism—the Joint Working Group (JWG) on Space Biology and Medicine. From the dawn of the space age, it has been the quest of humankind to understand its place in the universe. While nations can and do solve problems independently, it takes nations, working together, to accomplish great things. The formation of the JWG provided an opportunity for the opening of a series of productive relationships between the superpowers, the US and the Union of Soviet Socialist Republics (USSR); and served as a justification for continued relationship for medical assistance in spaceflight, and to showcase Earth benefits from space medicine research. This relationship has been played out on an international scale with the construction and operation of the International Space Station. The fundamental reason for this successful endeavor is a direct result of the spirit and perseverance of the men and women who have worked diligently side-by-side to promote science and move our understanding of space forward. This manuscript provides a historical perspective of the JWG; how it came about; its evolution; what it accomplished; and what impact it has had and continues to have in the 21st century with regard to human spaceflight and space life sciences research. It captures the spirit of this group, which has been in continuous existence for over 40 years, and provides a never before reported summary of its activities.

Doarn, Charles R.; Nicogossian, Arnauld E.; Grigoriev, Anatoly I.; Tverskaya, Galina; Orlov, Oleg I.; Ilyin, Eugene A.; Souza, Kenneth A.

2010-10-01

137

Representations of locally compact groups on QSL p -spaces and a p-analog of the Fourier–Stieltjes algebra  

Microsoft Academic Search

For a locally compact group $G$ and $p \\\\in (1,\\\\infty)$, we define $B_p(G)$ to\\u000abe the space of all coefficient functions of isometric representations of $G$\\u000aon quotients of subspaces of $L_p$ spaces. For $p =2$, this is the usual\\u000aFourier--Stieltjes algebra. We show that $B_p(G)$ is a commutative Banach\\u000aalgebra that contractively (isometrically, if $G$ is amenable) contains the

Volker Runde

2005-01-01

138

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.

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

2012-01-01

139

On duality and negative dimensions in the theory of Lie groups and symmetric spaces  

NASA Astrophysics Data System (ADS)

We give one more interpretation of the symbolic formulas U( - N) = U(N) and Sp( - 2N) = SO(2N) and show that they can be extended to the classical symmetric spaces using Macdonald duality for Jack and Jacobi symmetric functions.

Mkrtchyan, Ruben L.; Veselov, Alexander P.

2011-08-01

140

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

141

Clustering and group selection of multiple criteria alternatives with application to space-based networks.  

PubMed

In many real-world problems, the range of consequences of different alternatives are considerably different. In addition, sometimes, selection of a group of alternatives (instead of only one best alternative) is necessary. Traditional decision making approaches treat the set of alternatives with the same method of analysis and selection. In this paper, we propose clustering alternatives into different groups so that different methods of analysis, selection, and implementation for each group can be applied. As an example, consider the selection of a group of functions (or tasks) to be processed by a group of processors. The set of tasks can be grouped according to their similar criteria, and hence, each cluster of tasks to be processed by a processor. The selection of the best alternative for each clustered group can be performed using existing methods; however, the process of selecting groups is different than the process of selecting alternatives within a group. We develop theories and procedures for clustering discrete multiple criteria alternatives. We also demonstrate how the set of alternatives is clustered into mutually exclusive groups based on 1) similar features among alternatives; 2) ideal (or most representative) alternatives given by the decision maker; and 3) other preferential information of the decision maker. The clustering of multiple criteria alternatives also has the following advantages. 1) It decreases the set of alternatives to be considered by the decision maker (for example, different decision makers are assigned to different groups of alternatives). 2) It decreases the number of criteria. 3) It may provide a different approach for analyzing multiple decision makers problems. Each decision maker may cluster alternatives differently, and hence, clustering of alternatives may provide a basis for negotiation. The developed approach is applicable for solving a class of telecommunication networks problems where a set of objects (such as routers, processors, or intelligent autonomous vehicles) are to be clustered into similar groups. Objects are clustered based on several criteria and the decision maker's preferences. PMID:15369049

Malakooti, Behnam; Yang, Ziyong

2004-02-01

142

Distinctive Places, Suitable Spaces: Conceptualizing Mobile Group Occupational Duration and Landscape Use  

Microsoft Academic Search

While extreme mobility and ensconced sedentism can be easily distinguished in the archeological record, effective means are\\u000a lacking of discriminating between degrees of mobility that may range from seasonal shifts by farmers to recurrent moves across\\u000a the landscape as a way of life. Fortunately, site layout and the way space is used are related to expectations regarding length\\u000a of stay,

Deni J. Seymour

2009-01-01

143

Standard and Generalized Newtonian Gravities as ``Gauge'' Theories of the Extended Galilei Group - II: Dynamical Three-Space Theories  

Microsoft Academic Search

In a preceding paper we developed a reformulation of Newtonian gravitation as\\u000aa {\\\\it gauge} theory of the extended Galilei group. In the present one we\\u000aderive two true generalizations of Newton's theory (a {\\\\it ten-fields} and an\\u000a{\\\\it eleven-fields} theory), in terms of an explicit Lagrangian realization of\\u000athe {\\\\it absolute time} dynamics of a Riemannian three-space. They turn

R. De Pietri; L. Lusanna; M. Pauri

1994-01-01

144

The Effects of Status Space and Status Struggle on Group Decision Making.  

ERIC Educational Resources Information Center

Using Status Characteristic Theory as a theoretical framework, increasing status distinctions between professional group members were predicted to decrease the quantity of task related information and quality of decisions made in small problem-solving groups. Three experimental conditions were created: (1) occupational prestige manipulated, (2)…

Bloom, Joan R.

145

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

146

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

147

Innovation in the teaching of astrophysics and space science - spacecraft design group study  

NASA Astrophysics Data System (ADS)

This paper describes how the design of a scientific satellite can be used to provide both a stimulating and effective subject for a physics based group study. The group study divides the satellite into distinct subsystems and small teams of two or three students carry out the detailed design of each subsystem. The aim is to produce a complete satellite system design along with the choice of launch vehicle, orbit and communications system so that all the mission requirements can be met. An important feature of the group study is that it is a student led activity with staff acting as mentors. The development of key skills and important learning outcomes from the group study is discussed along with the method for assessment, structuring and resourcing the study.

Castelli, C.

2003-03-01

148

Report of a subcommittee on the nomenclature of n-dimensional crystallography. II. Symbols for arithmetic crystal classes, Bravais classes and space groups.  

PubMed

The Second Report of the Subcommittee on the Nomenclature of n-Dimensional Crystallography recommends specific symbols for R-irreducible groups in 4 and higher dimensions (nD), for centrings, for Bravais classes, for arithmetic crystal classes and for space groups (space-group types). The relation with higher-dimensional crystallographic groups used for the description of aperiodic crystals is briefly discussed. The Introduction discusses the general definitions used in the Report. PMID:12388880

Janssen, T; Birman, J L; Dénoyer, F; Koptsik, V A; Verger-Gaugry, J L; Weigel, D; Yamamoto, A; Abrahams, S C; Kopsky, V

2002-11-01

149

Working Group 4 of international standardization organization Experience of developing the standards of space environment  

NASA Astrophysics Data System (ADS)

Over the past decade space environment international standards have been developed within the scope of ISO WG4 activities. This has been the first attempt to develop international standards of physical phenomena of natural environment such as galactic cosmic rays, solar energetic particles, the Earth’s magnetic field, the ionosphere, the plasmasphere, etc. The main difficulty faced when developing the international standards is the lack of common methods for characterizing many natural phenomena. However, if methods have been successfully developed, such standards can play an outstanding role in the engineering requirements for spacecraft designs. This report is a survey of the current status of the international standards under development within the scope of the WG4 activity plan.

Panasyuk, M. I.

2006-01-01

150

The Stafford Commission synthesis group evaluation of power for the space exploration initiative  

NASA Astrophysics Data System (ADS)

Power for life support systems, experiments, operation of computers and communications equipment, preparation of sites, surface transportation, and extraction and processing resources from planetary surface is an essential element of the space exploration initiative. The philosophies for meeting power system requirements include: use of multiple units and power system types to ensure high reliability and safety; modular units that can be launched as a unit; minimization/elimination of off-earth assembly; emergency backup power for manned operational product improvement rather than developing the ultimate in the first unit; and adequate power options to satisfy anticipated power demand growth. The assessment approach used was to first examine the needs in terms of power level, duration, specific power, reliability, and need dates. Then, an assessment was performed of candidate technologies. A decision matrix was used to assess the candidate technologies relative to the needs. From this, candidate power systems were selected. Finally, particular systems are recommended for flight development.

Buden, David; Bartine, David; Harrison, Steve; Foremen, Joe; Biringer, Kent

151

Personal Computer (PC) thermal analyzer  

NASA Astrophysics Data System (ADS)

Rome Air Development Center (RADC) has developed an expert system based design verification tool to increase the efficiency of calculating device junction temperatures on printed circuit boards (PCBs). This tool, the Personal Computer (PC) Thermal Analyzer, was developed for reliability and electronic design engineers for use during the computer-aided design (CAD) phase. The PC Thermal Analyzer was developed through the combination of two technical areas, thermal analysis and expert systems. This intelligent analyzer is a more effective verification tool because traditional tools require much time and knowledge of thermal analysis, while the PC Thermal Analyzer is quick, requires no expertise in thermal analysis, and provides useful results during the CAD phase.

Vaccaro, James M.; Holzhauer, Douglas J.; Yaworsky, Paul S.

1990-03-01

152

European Modelling Group Solar Space Heating and Domestic Hot Water Systems.  

National Technical Information Service (NTIS)

The co-operative work within the European Modelling Group for Solar Heating Systems and Domestic Hot Water is undertaken as part of the CEC's research and development program on Solar Applications for Dwellings. During the last two years of operation of t...

O. Balslev-Olesen

1985-01-01

153

Clustering and group selection of multiple criteria alternatives with application to space-based networks  

Microsoft Academic Search

In many real-world problems, the range of conse- quences of different alternatives are considerably different. In ad- dition, sometimes, selection of a group of alternatives (instead of only one best alternative) is necessary. Traditional decision making approaches treat the set of alternatives with the same method of analysis and selection. In this paper, we propose clustering alter- natives into different

Behnam Malakooti; Ziyong Yang

2004-01-01

154

A walk through energy, discrepancy, numerical integration and group invariant measures on measurable subsets of euclidean space  

NASA Astrophysics Data System (ADS)

(A) The celebrated Gaussian quadrature formula on finite intervals tells us that the Gauss nodes are the zeros of the unique solution of an extremal problem. We announce recent results of Damelin, Grabner, Levesley, Ragozin and Sun which derive quadrature estimates on compact, homogenous manifolds embedded in Euclidean spaces, via energy functionals associated with a class of group-invariant kernels which are generalizations of zonal kernels on the spheres or radial kernels in euclidean spaces. Our results apply, in particular, to weighted Riesz kernels defined on spheres and certain projective spaces. Our energy functionals describe both uniform and perturbed uniform distribution of quadrature point sets. (B) Given , some measurable subset of Euclidean space, one sometimes wants to construct, a design, a finite set of points, , with a small energy or discrepancy. We announce recent results of Damelin, Hickernell, Ragozin and Zeng which show that these two measures of quality are equivalent when they are defined via positive definite kernels . The error of approximating the integral by the sample average of f over has a tight upper bound in terms the energy or discrepancy of . The tightness of this error bound follows by requiring f to lie in the Hilbert space with reproducing kernel K. The theory presented here provides an interpretation of the best design for numerical integration as one with minimum energy, provided that the ? defining the integration problem is the equilibrium measure or charge distribution corresponding to the energy kernel, K. (C) Let be the orbit of a compact, possibly non Abelian group, , acting as measurable transformations of and the kernel K is invariant under the group action. We announce recent results of Damelin, Hickernell, Ragozin and Zeng which show that the equilibrium measure is the normalized measure on induced by Haar measure on . This allows us to calculate explicit representations of equilibrium measures. There is an extensive literature on the topics (A-C). We emphasize that this paper surveys recent work of Damelin, Grabner, Levesley, Hickernell, Ragozin, Sun and Zeng and does not mean to serve as a comprehensive survey of all recent work covered by the topics (A-C).

Damelin, S.

2008-07-01

155

Smart Cards and PC Cards.  

National Technical Information Service (NTIS)

This document introduces both smart cards and PC cards and covers some of their relevant applications to information security. This includes their use in access control, as portable secure storage for cryptographic keys and for computing cryptographic fun...

M. Henderson

1999-01-01

156

Individual and grouping track pits etched in the exposed in a free space plastic track detectors  

NASA Astrophysics Data System (ADS)

New results concerned to the investigation of depth-dependent the pit-like surface-average and the grouping track-density distributions in the cosmic ray exposed column of CN-85 and CR-39 plastic solid state nuclear track detectors (SSNTD) are presented. Two main sources: solar cosmic ray protons and recoil nuclei for very short (length <3 ?m) track-pit formation are considered. Theoretical estimation of the total, uniform track-pit density indicates on failure of evidence of some additional radiation effects, partially, hypothetically conditioned with the Erzion theory. Some quantitative proofs of this hypothesis have been obtained in the measurements of the pit-groups. Totally, up to this time it was registered near of 30 pit groups with the surface pit-density in the interval of (1-15) × 106 cm2, that is two-three orders of magnitude higher than uniformly distributed track-pits on the same CR-39 plate surface. As a result of layer-by-layer investigation of the exposed CN-85 stock arrangement three pit swarms exactly correlated with the end point of high ionizing primary charge particle tracks were observed. Obtained data are considered in according to submission based on the probability of detection for the negative charged cosmic ray Erzion particles stopping events.

Kashkarov, L.; Bazhutov, Yu

2013-02-01

157

Building a research group of Space Physics at UAHuntsville -- the impact of an NSF career award  

NASA Astrophysics Data System (ADS)

G. Li (1,2) (1) Department of Physics, University of Alabama in Huntsville Huntsville, AL, 35899 (2) CSPAR, University of Alabama in Huntsville Huntsville, AL, 35899 The author joined the faculty of the department of Physics at University of Alabama in Huntsville in August 2008. He was awarded the NSF Career award ATM-0847719 in 2009. To date, the Career award has provided partial supports to one postdoc, two graduate students and three undergraduate students for a variety of periods. Three publications came out as a result of the award (one of which is first authored by one undergraduate). Another two publications are in preparation. The award also helped the PI to be further recognized by the field of space plasma physics and cosmic ray physics. For example, in July 2009, the PI was awarded the Young Scientist Medal by the International Union of Pure and Applied Physics (IUPAP); in April 2010, the PI won an Oak Ridge Associated Universities (ORAU) 2010 Ralph E. Powe Junior Faculty Enhancement Award. In short, the NSF CAREER has helped the PI to start his career at a level without which, will be impossible.

Li, G.

2011-12-01

158

Group dynamics during the EXEMSI isolation study. Experimental Campaign for the European Manned Space Infrastructure.  

PubMed

The objectives of this study were to investigate the social behavior, interrelations, cohesion, efficiency and team formation of the crew during 60 days of isolation and confinement, to make a critical comparison of a variety of test methods used for this purpose and to formulate recommendations for their applications in selection, training and support for future studies of this kind. The study consisted of three phases: (1) the pre-isolation period, in which initial individual and group assessment were made to understand the motivation, characteristics, and styles of the crew members, the state of the crew, and to make a prognosis for the behavior of the group and its members, (2) the isolation period, with tests and observations to follow and analyze behavior and group dynamics of the crew, and to detect manifestations of stress, and (3) the post-isolation period with final assessment and debriefing. During these three periods individual and group tests were carried out. Direct methods, questionnaires and tests, as well as indirect methods, observations of behavior, were used. These had cognitive, affective-emotional and social components; they were quantitative, qualitative or a combination. Before isolation the crew members expressed strong confidence in the team and in their own personal capability. The leadership of the Commander seemed uncontested. Crew functioning during this period was conflict-free, but was structured in a rather rigid and defensive way (isolation of affects, denial of anxiety). Apparently, the members strongly needed to present a good image image of themselves. The relatively short period of the experiment, and the absence of real risk suggested that the crew would be able to maintain their cohesion, but in a real spaceflight situation this behavior could be inadequate and even dangerous. The pre-isolation prognosis for crew behavior during isolation was validated to a large extent. During isolation there were no clear manifestations of stress. Nevertheless, the confinement and isolation were experienced as the major stress factors. The crew members described themselves as a heterogeneous but harmonious group that was successful in their mission. In fact, the team maintained its cohesion by opposing external authority, using management as a scapegoat. Occasionally, in times of crisis, they also criticized ground crew. The Commander supported this attitude. Strongly differences in personality and behavior were noted. Analysis of the sociometric data showed that the asserted harmony was more apparent than real. It is questionable whether the group cohesion would have persisted in a life threatening crisis or even in a prolongation of the experiment. The most reliable instruments for this type of survey seem to be: group methods, non-obstructive tests, indirect instruments, and qualitative tools. The least reliable are: strictly quantitative methods, self-evaluations, standard debriefing techniques, since these reinforced in most cases subjects' defenses in an unconscious avoidance of criticism. Several recommendations were made for the organization, definition of objectives, experiment selection, crew selection, roles of external management and personnel. In particular, it is felt to be necessary to explain the aims of the mission to the subjects, to give clear and complete information, to establish confident and cooperative relations with the crew. It is essential to allow dialogue, to take opinions and suggestions of the crew seriously, and to establish clear rules of confidentiality. PMID:8814802

Cazes, C; Rosnet, E; Bachelard, C; Le Scanff, C; Rivolier, J

1996-01-01

159

The Power PC 601 microprocessor  

Microsoft Academic Search

The PowerPC 601 microprocessor, the first of a family of processors based on the PowerPC architecture, is described. The general-purpose processor contains a 32-Kb cache and a superscalar machine organization that allows dispatch and execution of up to three instructions each clock cycle. The bus interface and storage control mechanisms can be configured for a wide range of system designs,

Michael C. Becker; Michael S. Allen; C. R. Moore; J. S. Muhich; D. P. Tuttle

1993-01-01

160

LETTER TO THE EDITOR: Real space renormalization group analysis of the random field Ising model  

NASA Astrophysics Data System (ADS)

We present an analytic Migdal - Kadanoff renormalization group analysis of the random field Ising model. The renormalization flows to a zero-temperature critical point, from which we calculate independently three critical exponents in arbitrary dimension. In three dimensions the magnetization exponent 0305-4470/29/21/002/img1, and the Schwartz - Soffer inequality is almost satisfied as an equality. Expanding analytically in 0305-4470/29/21/002/img2 we find that 0305-4470/29/21/002/img3 and the distance from the upper bound of the equality go to zero exponentially with 0305-4470/29/21/002/img4.

Fortin, J.-Y.; Holdsworth, P. C. W.

1996-11-01

161

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

162

Evaluating PC-Board Materials and Processes: Study evaluates the limits of fine-line resolution on copper-clad PC boards.  

National Technical Information Service (NTIS)

This citation summarizes a one-page announcement of technology available for utilization. A document evaluates the limits of resolution between the conductor lines and spaces that are presently attainable on copper-clad PC boards. The evaluation considers...

1983-01-01

163

GROUP  

Microsoft Academic Search

In this paper we continue the study ofalg 1 (S) for minimal surfaces of general type S satisfying K2 S < 3?(S). We show that, if K 2 S = 3?(S) 1 and |?alg 1 (S)| = 8, then S is a Campedelli surface. In view of the results of (MP1) and (MP2), this implies that the fundamental group of

CIRO CILIBERTO; MARGARIDA MENDES LOPES; RITA PARDINI

164

AUTOPLAN: A PC-Based Automated Mission Planning Tool.  

National Technical Information Service (NTIS)

A PC-based automated mission and resource planning tool, AUTOPLAN, is described, with application to small-scale planning and scheduling systems in the Space Station program. The input is a proposed mission profile, including mission duration, number of a...

F. C. Paterra M. S. Allen G. F. Lawrence

1987-01-01

165

Crystal families and systems in higher dimensions, and geometrical symbols of their point groups. II. Cubic families in five- and n-dimensional spaces  

NASA Astrophysics Data System (ADS)

The definition, properties and symbols of the iso cubic groups are given. The mono cubic crystal families of space E^n are defined and listed for n = 3 to n = 7. As an application, four crystal families of space E^5 are studied in detail.

Weigel, D.; Phan, T.; Veysseyre, R.

2008-11-01

166

Saturated Kochen-Specker-type configuration of 120 projective lines in eight-dimensional space and its group of symmetry  

SciTech Connect

There exists an example of a set of 40 projective lines in eight-dimensional Hilbert space producing a Kochen-Specker-type contradiction. This set corresponds to a known no-hidden variables argument due to Mermin. In the present paper it is proved that this set admits a finite saturation, i.e., an extension up to a finite set with the following property: every subset of pairwise orthogonal projective lines has a completion, i.e., is contained in at least one subset of eight pairwise orthogonal projective lines. An explicit description of such an extension consisting of 120 projective lines is given. The idea to saturate the set of projective lines related to Mermin's example together with the possibility to have a finite saturation allow to find the corresponding group of symmetry. This group is described explicitely and is shown to be generated by reflections. The natural action of the mentioned group on the set of all subsets of pairwise orthogonal projective lines of the mentioned extension is investigated. In particular, the restriction of this action to complete subsets is shown to have only four orbits, which have a natural characterization in terms of the construction of the saturation.

Ruuge, Artur E.; Oystaeyen, Freddy van [Department of Quantum Statistics and Field Theory, Faculty of Physics, Moscow State University , Vorobyovy Gory, 119899 Moscow (Russian Federation); Department of Mathematics and Computer Science, University of Antwerp, Middelheim Campus, Building G, Meddelheimlaan 1, B-2020 Antwerp (Belgium); Department of Mathematics and Computer Science, University of Antwerp, Middelheim Campus, Building G, Meddelheimlaan 1, B-2020 Antwerp (Belgium)

2005-05-01

167

Critical Dynamics of the Xy-Model on the One-Dimensional Superlattice by Position Space Renormalization Group  

NASA Astrophysics Data System (ADS)

The critical dynamics of the isotropic XY-model on the one-dimensional superlattice is considered in the framework of the position space renormalization group theory. The decimation transformation is introduced by considering the equations of motion of the operators associated to the excitations of the system, and it corresponds to an extension of the procedure introduced by Stinchcombe and dos Santos (J. Phys. A18, L597 (1985)) for the homogeneous lattice. The dispersion relation is obtained exactly and the static and dynamic scaling forms are explicitly determined. The dynamic critical exponent is also obtained and it is shown that it is identical to the one of the XY-model on the homogeneous chain.

Lima, J. P. De; Gonçalves, L. L.

168

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

169

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); Nancy R. Gough (American Association for the Advancement of Science;Editor of Science's STKE REV); Jay A. Blundon (Rhodes College;Department of Biology REV)

2006-09-05

170

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 background and details for performing the lab are provided along with suggestions for assessing student performance and understanding.

Elizabeth Adler (AAAS;); Nancy Gough (AAAS;); Jay Blundon (Department of Biology, Rhodes College;)

2006-09-05

171

Time Measurement on the PC.  

National Technical Information Service (NTIS)

PC's can be used to measure time intervals as small as 2 microseconds. This article shows how this can be done. It describes a program developed for the faculty of Biology at the University of Groningen, where it is used to measure time intervals of pulse...

W. A. Vervoort

1993-01-01

172

Storage in the power PC  

Microsoft Academic Search

Power PC memory is innovative because it incorporates leading-edge approaches to hiding the latency of memory accesses. Although features like access reordering have long been the subject of academic research, such improvements are only now coming into widespread commercial use. Using these features requires a shift in thinking, but designers and programmers can achieve significant performance advantages. We also compare

Janice M. Stone; Robert P. Fitzgerald

1995-01-01

173

Design and Implementation of a Prototype PC Based Graphical and Interactive MILSATCOM Requirements Database System.  

National Technical Information Service (NTIS)

This thesis develops a prototype PC based Military Satellite Communications (MILSATCOM) Requirements Database (MRDB) application for U.S. Space Command, using Microsoft's Access relational database management system (DBMS) for Windows. It demonstrates the...

W. M. Major

1993-01-01

174

Requirements for space-based observations in fire management: a report by the Wildland Fire Hazard Team, Committee on Earth Observation Satellites (CEOS) Disaster Management Support Group (DMSG)  

Microsoft Academic Search

The Wildland Fire Hazard Team reviewed potential requirements for space-based observations in fire management. The team produced a report, developed under the auspices of the Disaster Management Support Group (DMSG) of the G-7 Committee on Earth Observation Satellites (CEOS). The document was prepared by an international working group, with experience in the field of remote sensing as applied to wildland

T. J. Lynham; C. W. Dull; A. Singh

2002-01-01

175

IBM-PC in the Laboratory  

NASA Astrophysics Data System (ADS)

1. Introduction; 2. Instrumentation structure and using the IBM-PC; 3. Thermistor experiments; 4. Timing; 5. Thermal diffusion; 6. IBM-PC architecture and assembly language programming; 7. Viscosity measurement; 8. Interrupts; 9. Other topics; Appendices; Index.

Thompson, Bruce Gregory; Kuckes, A. F.

1992-03-01

176

Structure solution of network materials by solid-state NMR without knowledge of the crystallographic space group.  

PubMed

An algorithm is presented for solving the structures of silicate network materials such as zeolites or layered silicates from solid-state (29)Si double-quantum NMR data for situations in which the crystallographic space group is not known. The algorithm is explained and illustrated in detail using a hypothetical two-dimensional network structure as a working example. The algorithm involves an atom-by-atom structure building process in which candidate partial structures are evaluated according to their agreement with Si-O-Si connectivity information, symmetry restraints, and fits to (29)Si double quantum NMR curves followed by minimization of a cost function that incorporates connectivity, symmetry, and quality of fit to the double quantum curves. The two-dimensional network material is successfully reconstructed from hypothetical NMR data that can be reasonably expected to be obtained for real samples. This advance in "NMR crystallography" is expected to be important for structure determination of partially ordered silicate materials for which diffraction provides very limited structural information. PMID:23415450

Brouwer, Darren H

2013-01-30

177

Representations of locally compact groups on QSL_p-spaces and a p-analog of the Fourier-Stieltjes algebra  

Microsoft Academic Search

For a locally compact group $G$ and $p \\\\in (1,\\\\infty)$, we define $B_p(G)$ to be the space of all coefficient functions of isometric representations of $G$ on quotients of subspaces of $L_p$ spaces. For $p =2$, this is the usual Fourier--Stieltjes algebra. We show that $B_p(G)$ is a commutative Banach algebra that contractively (isometrically, if $G$ is amenable) contains the

Volker Runde

2004-01-01

178

Occlusion in the primary dentition. Part 1: A preliminary report on comparison of antero-posterior relationships and spacing among children of the major Nigerian ethnic groups.  

PubMed

This paper compares the antero-posterior occlusal pattern and arch spacing in the primary dentition of Nigerian children from the 3 major ethnic groups in the country Ibo, Yoruba and Hausa tribes. This is a cross-sectional epidemiological study involving eight randomly selected pre-primary schools and day-care centers in Ibadan and Lagos cities of Nigeria. Two hundred and sixty-nine 3-5-year-old children consisting of 125 (46.5%) males and 144 (53.6%) females were examined. A two-stage sampling method was adopted. The occlusions of the children were assessed according to the criteria by Foster and Hamilton, under natural illumination in their schools premises. Chi-square statistic was used to analyse the data. No statistically significant differences were observed in the molar and canine relationships among the ethnic groups (p > 0.05). Highly statistically significant differences were noted in relation to spacing of the arches (p = 0.001) in both the anterior and posterior segments. Also, statistically significant differences were found in relation to post canine spaces (p < 0.05) but not with pre-canine spaces. Spacing was found most in the Ibo ethnic group children. Although no statistically significant ethnic differences were found in the molar relationships of the study sample, very statistically significant differences were revealed in the spacing of the arches in both incisor and molar regions. PMID:16910111

Onyeaso, C O

2006-06-01

179

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

180

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

181

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

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

Clonal nature of the immune response to phosphorylcholine (PC). V. Cross-idiotypic specificity among heavy chains of murine anti-PC antibodies and PC-binding myeloma proteins  

PubMed Central

Seven mouse myeloma proteins with specificity for phosphorylcholine (PC) were found to share a common antigenic determinant. This group of proteins contained members which differed in genetic origin, heavy chain class, kappa-chain subgroup, individual antigenic determinants and specificity for choline analogues. The cross-idiotypic determinant, VH-PC, was antigenically similar in each of the proteins and was associated with the variable portion of the heavy chain in the region of the antibody combining site. Further studies showed that an indistinguishable determinant was present on IgM anti-PC antibodies isolated from all strains of mice tested regardless of histocompatibility or heavy chain allotype. In view of the finding that this cross-idiotypic determinant was not found on antibodies or myeloma proteins which lacked specificity for PC, the data strongly suggest that a particular heavy chain variable region has been preserved in all mouse antibodies with specificity for PC.

1975-01-01

184

Group 11 metal chemistry of a tetradentate ligand, phenylene-1,4-diaminotetra(phosphonite), p-C6H4[N{P(OC6H4OMe-o)2}2]2.  

PubMed

The Cu(I), Ag(I), and Au(I) chemistry of a tetradentate ligand (phenylene-1,4-diaminotetra(phosphonite), p-C(6)H(4)[N{P(OC(6)H(4)OMe-o)(2)}(2)](2) (P(2)NPhiNP(2)) (1)) is described. The flexional conformations in 1 leads to interesting structural variations in transition-metal complexes. The reaction of 1 with 4 equiv of CuX (where X = Br and I) produce the tetranuclear complexes, [{Cu(2)(mu-X)(2)(NCCH(3))(2)}(2)(mu-P(2)NPhiNP(2))] (where X = Br (2) or X = I (3)) in quantitative yield. Treatment of 3 with an excess of pyridine, 2-(piperazin-1-yl)pyrimidine, and pyrazole yielded the tetra-substituted derivatives, [{Cu(2)(mu-I)(2)(L)(2)}(2)(mu-P(2)NPhiNP(2))] (where L = pyridine (4), 2-(piperazin-1-yl)pyrimidine (5), or pyrazole (6)). Similar reactions of 3 with 1,10-phenanthroline (phen) and 2,2'-bipyridine in a 1:2 molar ratio afford the disubstituted derivatives, [(Cu(2)(mu-I))(2)I(2)(phen)(2)(mu-P(2)NPhiNP(2))] (7) and [(Cu(2)(mu-I))(2)I(2)(bipy)(2)(mu-P(2)NPhiNP(2))] (8). The o-methoxyphenoxy substituents on phosphorus in complexes 5 and 7 adopt approximately parallel planar conformations and contain lattice solvents. The reaction of 3 with 1,4-diazabicyclo[2.2.2]octane (DABCO) in a 1:2 molar ratio in a dichloromethane-acetonitrile mixture leads to the formation of an ionic complex [N(CH(2)CH(2))(3)N(+)CH(2)Cl](2)[(Cu(2)(Cl)(I)(2))(2)(NCCH(3))(2)(mu-P(2)NPhiNP(2))](2-) (9), as a result of the chloromethylation of DABCO. Treatment of 1 with 4 equiv of AgClO(4) produces [{Ag(2)(mu-ClO(4))(2))(2)(C(4)H(8)O)(2)}(2)(mu-P(2)NPhiNP(2))] (10). Displacement of perchlorate ions in 10 by PhN{P(OC(6)H(4)OMe-o)(2)}(2) (PNP) or 2,2'-bipyridine yielded [(mu-PNP)(2)Ag(2)(mu-P(2)NPhiNP(2))Ag(2)(mu-PNP)(2)](ClO(4))(4) (11) and [{Ag(2)(bipy)(2)}(2)(mu-P(2)NPhiNP(2))](ClO(4))(4) (12), respectively. The similar reaction of 1 with 2 equiv of AgOTf, in the presence of 4,4'-bipyridine, gave a three-dimensional Ag(I) coordination polymer, [{Ag(2)(C(10)H(8)N(2))(2)(CH(3)CN)(2)}(2)(P(2)NPhiNP(2))](n)(OTf)(4n) (13). The reactions of 1 with [AuCl(SMe(2))], in appropriate ratios, afford the tetranuclear and dinuclear complexes, [(Au(2)Cl(2))(2)(mu-P(2)NPhiNP(2))] (14) and [(AuCl)(2)(P(2)NPhiNP(2))] (15). Complex 14 undergoes moisture-assisted P-N bond cleavage in the presence of PhN{P(OC(6)H(4)OMe-o)(2)}(2) to give [p-NH(2)C(6)H(4)N{P(OC(6)H(4)OMe-o)(2)}(2)Au(2)Cl(2)] (17) and [PhN{P(OC(6)H(4)OMe-o)(2)}(2)Au(2)Cl(2)]. The structures of the complexes 5, 7-10, 12-15, and 17 are confirmed by single-crystal X-ray diffraction studies. PMID:19317408

Ganesamoorthy, Chelladurai; Balakrishna, Maravanji S; Mague, Joel T

2009-04-20

185

“Here is the knowledge-where should I put it?” Findings from a study of how knowledge spaces are used within a support group  

Microsoft Academic Search

In order to design useful knowledge media spaces for knowledge workers it is essential that we understand the nature of the work conducted and the knowledge applied in real settings. The paper reports from a study of how a group of quality assurance specialists in the pharmaceutical industry gather, structure and distribute information and knowledge. Based on the findings, a

P. H. Carstensen; U. Snis

1999-01-01

186

PC-Bang (Room) Culture: A Study of Korean College Students' Private and Public Use of Computers and the Internet  

Microsoft Academic Search

The purpose of this study was to examine how Korean college students use computers within the PC-Bangs as well as at home. Data on media usage and PC-Bang usage pat- terns was collected from 291 University of Ulsan students. Results suggest that PC-Bangs are used mainly for game playing and have become a male-dominated play space. Female students, however, tended

Kym Stewart; Hyewon Park Choi

2003-01-01

187

Public opinion and interest group positions on open-space issues in Albuquerque, New Mexico, USA: Implications for resource management  

Microsoft Academic Search

The purpose of this research was to elicit and compare the open-space preferences of citizens and openspace experts in Albuquerque, New Mexico, USA. A randomly selected sample of 492 citizens and 35 open-space experts participated in a telephone survey during May 5 18, 1986. The following hypothesis was tested and used as a guideline for the study: HO1: There is

Thomas Allan Tannery

1987-01-01

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

Pre-Service Teacher Training in Mathematics Using Tablet PC Technology  

Microsoft Academic Search

This study focuses on the use of innovative Tablet PC technology in learning and teaching mathematics. Specifically the effects of incorporating Tablet PC technology in pre-service teachers' mathematics education were analyzed. The significant impact of technology use in mathematics ed- ucation was assessed by evaluating and comparing students' final project and course grades. Grade performance of two groups of students

Olga Kosheleva; Ana Medina-Rusch; Vera Ioudina

2007-01-01

190

HDTV-PC for media convergence  

Microsoft Academic Search

We developed the ARIB-compliant HDTV-PC and used it for experimentation of unified applications by both digital broadcasting and broadband communication. With the rich viewing of HD video and synchronized interactive data services, a HDTV-PC solution is a more compelling one than each of the digital DTV and broadband PC. By combining the rich viewing by HD video and abundant information

Takashi Kan; Hironobu Abe; Toyoshi Makino; Heikan Izumi; Norio Shiratori

2002-01-01

191

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

192

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

National Technical Information Service (NTIS)

NASA's mission is 'to understand and protect our home planet, to explore the universe and search for life, and to inspire the next generation of explorers' The Systems Management Office at Johnson Space Center (JSC) is searching for methods to effectively...

M. Tavana

2005-01-01

193

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

ERIC Educational Resources Information Center

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…

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

2009-01-01

194

Large-Scale PC Management and Configuration for SNS Diagnostics  

SciTech Connect

The Spallation Neutron Source (SNS) project's diagnostics group has begun its implementation of more than 300 PC-based Network Attached Devices (NADs). An implementation of this size creates many challenges, such as distribution of patches and software upgrades; virus/worm potentials; and the configuration management, including interaction with the SNS relational database. As part of the initial solution, a base operating system (OS) configuration has been determined and computer management software has been implemented. Each PC requires a unique configuration, but all are based on a common OS and supporting applications. The diagnostics group has started with an implementation of an XP Embedded (XPe) OS and uses Altiris registered eXpress Deployment Solution{sup TM}. The use of XPe and Altiris gives the diagnostics group the ability to easily configure, distribute, and manage software on a large scale. This paper describes the initial experience and discusses plans for the future.

Murphy, Darryl J.; Purcell, J. David [ORNL, Oak Ridge, TN 37830 (United States)

2004-11-10

195

Large-Scale PC Management and Configuration for SNS Diagnostics  

NASA Astrophysics Data System (ADS)

The Spallation Neutron Source (SNS) project's diagnostics group has begun its implementation of more than 300 PC-based Network Attached Devices (NADs). An implementation of this size creates many challenges, such as distribution of patches and software upgrades; virus/worm potentials; and the configuration management, including interaction with the SNS relational database. As part of the initial solution, a base operating system (OS) configuration has been determined and computer management software has been implemented. Each PC requires a unique configuration, but all are based on a common OS and supporting applications. The diagnostics group has started with an implementation of an XP Embedded (XPe) OS and uses Altiris® eXpress Deployment Solution™. The use of XPe and Altiris gives the diagnostics group the ability to easily configure, distribute, and manage software on a large scale. This paper describes the initial experience and discusses plans for the future.

Murphy, Darryl J.; Purcell, J. David

2004-11-01

196

Activity budget, diet, and use of space by two groups of squirrel monkeys (Saimiri sciureus) in eastern Amazonia.  

PubMed

Squirrel monkeys (Saimiri spp.) are widely distributed in the Amazon basin. This study describes the ecological and behavioral patterns of two social groups of S. sciureus in forests adjacent to the Tucuruí hydroelectric reservoir in eastern Amazonia, including range size, activity budgets, and composition of the diet. The groups were monitored at Base 4 (group B4) and Germoplasma Island (group GI). Quantitative behavioral data were collected using instantaneous scan sampling to record behavior, substrate use, and height. Home ranges were delimited using a GPS to determine group position after each 50 m of movement. Home ranges were 75.0 ha for group B4 (39 members) and 77.5 ha for group GI (32 members). The use of vertical strata was well defined, with a marked preference for the middle and lower levels of the canopy. The activity budgets of both groups were typical of those of other squirrel monkeys and were dominated by foraging (B4 = 48.7 %; GI = 49.6 %), moving (both groups 28.9 %), and feeding (B4 = 14.6 %; GI = 12.4 %). Resting was rare (B4 = 3.5 %; GI = 2.6 %) and less common than social behavior (B4 = 4.3 %; GI = 6.4 %). The diet of both groups was dominated by plant material (B4 = 70.7 % of feeding records; GI = 71.4 %), which is in contrast with the more insectivorous diets recorded for Saimiri at other sites. Group GI spent more time foraging during the dry season, whereas group B4 spent more time in the rainy season when the consumption of fruit increased (significantly, in the case of group GI). The less insectivorous diet of these groups may be due to a number of factors, including the unique habitat configuration at the site and reduced hydrological stress due to the proximity of the reservoir. PMID:23546826

Pinheiro, Tatyana; Ferrari, Stephen F; Lopes, Maria Aparecida

2013-04-02

197

An augmented reality learning space for PC DIY  

Microsoft Academic Search

Because of the advances of computer hardware and software, Computer Aided Instruction (CAI) makes learning effective and interesting through the use of interactive multimedia technology. Recently, Augmented Reality (AR) technology has begun to surge as a new CAI tool because of its ability to create tangible and highly interactive user interface. In addition, recent studies have shown that the learning

Heien-Kun Chiang; Yin-Yu Chou; Long-Chyr Chang; Chun-Yen Huang; Feng-Lan Kuo; Hown-Wen Chen

2011-01-01

198

BEYOND THE TABLET PC USING THE TABLET PC IN A COLLABORATIVE LEARNING ENVIRONMENT  

Microsoft Academic Search

This research focuses on the use of the Tablet PC in education. The research explores the development of the Tablet PC and introduces the Classroom Presenter software. Implementation efforts of both the Tablet PC and the Classroom Presenter software at Coastal Carolina University are explored.

JEAN H. FRENCH

199

RDA-PC System User's Guide.  

National Technical Information Service (NTIS)

The RDA-PC System was designed to provide: (1) A PC-based data entry tool for the Research, Development and Acquisition Annual Review System (RDAARS). This tool minimizes redundant data entry, performs data consistency checks immediately, and provides hel...

1993-01-01

200

LP-DOS magnifies the PC screen  

Microsoft Academic Search

As a visually impaired computer user the author needed a simple solution that would allow him and others to see and use the vast range of PC text and graphics programs. He created LP-DOS (Large Print DOS). LP-DOS is a software package that can run on any PC or laptop. It can be used anywhere: business, home, or school. Once

D. Simkovitz

1992-01-01

201

PC-based tele-audiometry.  

PubMed

A personal computer (PC)-based audiometer was developed for interactive remote audiometry. This paper describes a tele-audiometric system and evaluates the performance of the device when compared with conventional face-to-face audiometry. The tele-audiometric system is fully PC-based. A sound card featuring a high-quality digital-to-analog converter is used as a pure-tone generator. The audiometric programs were developed based on Microsoft Windows in order to maximize usability. Audiologists and their subjects can use the tele-audiometry system as one would utilize any PC application. A calibration procedure has been applied for the standardization of sound levels in the remote system. The performance of this system was evaluated by comparing PC-based audiometry with the conventional clinical audiometry system for 37 subjects. Also, performance of the PC-based system was evaluated during use at a remote site. The PC-based audiometry system estimated the audiometric threshold with an error of less than 2.3 dBSPL. Only 10.7% of the results exhibited an error greater than 5 dBSPL during use at a remote site. The PC-based tele-audiomerty showed acceptable results for use at a remote site. This PC-based system can be used effectively and easily in many locations that have Internet access but no local audiologists. PMID:17999612

Choi, Jong Min; Lee, Haet Bit; Park, Cheol Soo; Oh, Seung Ha; Park, Kwang Suk

2007-10-01

202

Using a Tablet PC for Classroom Instruction  

Microsoft Academic Search

An increasing trend for lecture-based courses is for instructors to convert their lecture notes to slides that can be projected electronically. While there are many advantages to electronic projection, a large drawback is the loss of interactivity and spontaneity that can result. The use of a tablet PC by the instructor promises to overcome this difficulty. The tablet PC, combined

Carol C. W. Hulls

2005-01-01

203

PC-based fault finder  

SciTech Connect

Electric utilities are continually pressed to stay competitive while meeting the increasing demand of today's sophisticated customer. Advances in electron equipment and the improved array of electric driven devices are setting new standards for improved reliability and quality of service. Besides the specifications on voltage and frequency regulation and the permitted harmonic content, to name a few, the number and duration of service interruptions have a dramatic direct effect on the customer. Accurate fault locating reduces transmission line patrolling and is of particular significance in repairing long lines in rough terrain. Shortened outage times, reduced equipment degrading and stress on the system, fast restored service, and improved revenue are immediate outcomes of fast fault locating which insure minimum loss of system security. This article focuses on a PC-based (DOS) computer program that has unique features for identifying the type of fault and its location on overhead transmission/distribution lines. Balanced and unbalanced faults are identified and located accurately while accounting for changes in conductor sizes and network configuration. The presented concepts and methodologies have been spurred by Otter Tail Power's need for an accurate fault locating scheme to accommodate multiple feeders with mixed lone configurations. A case study based on a section of the Otter Tail network is presented to illustrate the features and capabilities of the developed software.

Bengiamin, N.N. (Univ. of North Dakota, Grand Forks, ND (United States)); Jensen, C.A. (Univ. of North Dakota, Grand Forks, ND (United States). Electrical Engineering Dept. Otter Tail Power Co., Fergus Falls, MN (United States). System Protection Group); McMahon, H. (Otter Tail Power, Fergus Falls, MN (United States))

1993-07-01

204

A normalized family of representations of the group of motions of a Euclidean space and the inverse problem of the representation theory of this group  

SciTech Connect

There exists a well-known holomorphic family T{sup {lambda}} of representations of the isometry group of R such that T{sup -{lambda}}{approx}T{sup {lambda}} for {lambda}{ne}0. This paper presents a holomorphic family V{sub R}{sup {lambda}}, |{lambda}|

Ismagilov, R S [N.E. Bauman Moscow State Technical University, Moscow (Russian Federation); Sultanov, Sh Sh [Nizhnevartovsk State Pedagogical University, Nizhnevartovsk (Russian Federation)

2004-12-31

205

Collective surface diffusion of repulsively interacting particles on a triangular lattice: Comparison of real-space renormalization group and Monte Carlo approaches  

Microsoft Academic Search

A two-dimensional lattice-gas model with triangular symmetry is investigated by using the real-space renormalization group (RSRG) approach with blocks of different size and symmetries. It has been shown that the precision of this method depends strongly not only on the number of sites in the block but also on its symmetry. In general, the accuracy of the method increases with

A. A. Tarasenko; F. Nieto; L. Jastrabík; C. Uebing

2001-01-01

206

Scaling and Renormalization Group in Replica-Symmetry-Breaking Space: Evidence for a Simple Analytical Solution of the Sherrington-Kirkpatrick Model at Zero Temperature  

Microsoft Academic Search

Using numerical self-consistent solutions of a sequence of finite replica symmetry breakings (RSB) and Wilson's renormalization group but with the number of RSB steps playing a role of decimation scales, we report evidence for a nontrivial T-->0 limit of the Parisi order function q(x) for the Sherrington-Kirkpatrick spin glass. Supported by scaling in RSB space, the fixed point order function

R. Oppermann; D. Sherrington

2005-01-01

207

Color Grouping in Space and Time: Evidence From Negative Color-Based Carryover Effects in Preview Search  

Microsoft Academic Search

Five experiments addressed the role of color grouping in preview search (D. G. Watson & G. W. Humphreys, 1997). Experiment 1 used opposite color ratios of distractors in preview and second search displays, creating equal numbers of distractors in each color group in the final display. There was selective slowing for new targets carrying the majority color of the old

Jason J. Braithwaite; Glyn W. Humphreys; John Hodsoll

2003-01-01

208

Replication and inheritance of Nocardia plasmid pC1.  

PubMed

Nocardia sp. C-14-1, isolated from acrylic fiber wastewater, can degrade long-chain alkanes and succinonitrile efficiently. Here we report the characterization of an indigenous plasmid pC1. The overall nucleotide sequence of pC1 consisted of 5841 bp. The five ORFs, encoding a DNA recombinase, replication protein (Rep(pC1)) and three proteins of unknown function, were predicted on pC1. The Rep(pC1) displayed its homology with the Rep of Rhodococcus large plasmid p33701, suggesting a theta type of replication. An Escherichia coli plasmid (containing the single rep(pC1) gene) propagated autonomously in low copy number in Nocardia or Rhodococcus, suggesting that rep(pC1) was an essential gene for plasmid replication. The plasmid (containing the single rep(pC1) gene) presented as inheritance unstable hints that other pC1 loci were required for the stable inheritance of plasmids. By comparison of the plasmid-borne Rep proteins, we classify Rhodococcus or Nocardia plasmids into four groups. PMID:16842357

Shen, Meijuan; Fang, Ping; Xu, Deqiang; Zhang, Yalei; Cao, Weihuan; Zhu, Yingmin; Zhao, Jianfu; Qin, Zhongjun

2006-08-01

209

On the identification of fossil tracks of Galactic space nuclei from the Th-U group in olivine crystals from meteorites  

NASA Astrophysics Data System (ADS)

This paper considers the origin of the group of space nuclei tracks of lengths between 190 and 220 microns in the meteorites Maryalakhti and Eagle Station. Several hundred 1- to 5-micron-size microscopic-size olivine crystals from these meteorites (obtained by cracking larger monocrystals) were irradiated by U-238 nuclei (in the energy range 30-70 MeV/nucleon), and the etching length spectra of accelerated U-238 nuclei were compared with fossil tracks in these crystals. The crystals containing tracks of U-238 were annealed under conditions identical to those used for the examination of fossil tracks in olivine crystals from these meteorites (Lhagvasuren et al., 1980). The comparison showed that the group of fossil tracks observed in Galactic space nuclei of length 200-210 microns is defined by the nuclei of the Th-U group. Tracks of the length of 350 microns (i.e., close in length to the group of fossil tracks of 340-360 microns) were also observed in the U-238 spectrum.

Perelygin, V. V. P.; Stetsenko, S. G.; Kashukeev, N. T.; Petrova, R. I.

210

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

211

Cytotoxic role of advanced glycation end-products in PC12 cells treated with ??amyloid peptide.  

PubMed

Alzheimer's disease (AD) is the most common type of dementia afflicting the elderly. Recent studies have increasingly suggested that a high concentration of advanced glycation end products (AGEs) may be important in AD pathogenesis. However, the mechanisms and pathways involved remain unknown. The aim of this study was to explore whether the mechanism of the effect of AGEs on A??PC12 cells [PC12 cells treated with ??amyloid (A?) peptide] was associated with oxidative stress; and to study whether inhibiting the activity of the receptor for AGE (RAGE) attenuated the toxic effect of AGEs and A? on PC12 cells. Several PC12 cells were pretreated with A?, and were then treated with different concentrations of AGEs. Other PC12 cells were treated with trypsin, a pancreatic protein enzyme and an inhibitor of RAGE, and were then treated with A? and AGEs. Apoptosis was measured by flow cytometry (FCM) and cell viability was measured by MTT assay. RAGE and nuclear factor??B (NF??B) were measured by reverse transcription-polymerase chain reaction (RT?PCR) assay. With an increase in AGE concentration, the viability of A??PC12 cells treated with AGEs decreased. However, the A??PC12 cell viability was greater in the trypsin group than in the non?trypsin group. Cell apoptosis rates and mRNA expression of RAGE and NF??B in A??PC12 cells treated with AGEs were significantly higher than in the A??PC12 cells. AGEs and A? were neurotoxic, and RAGE triggered the neural cytotoxic role of AGEs in A??PC12 cells. The molecular mechanisms may be connected with the expression of NF??B and apoptosis mediated by RAGE. Inhibiting the activity of RAGE may mitigate the toxic effect of AGEs and A? on neural cells. PMID:23799541

Yan, Fu-Ling; Han, Guo-Ling; Wu, Guan-Jin

2013-06-25

212

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

213

Auditing Consistency and Usefulness of LOINC Use among Three Large Institutions - Using Version Spaces for Grouping LOINC Codes  

PubMed Central

Objectives We wanted to develop a method for evaluating the consistency and usefulness of LOINC code use across different institutions, and to evaluate the degree of interoperability that can be attained when using LOINC codes for laboratory data exchange. Our specific goals were to: 1) Determine if any contradictory knowledge exists in LOINC. 2) Determine how many LOINC codes were used in a truly interoperable fashion between systems. 3) Provide suggestions for improving the semantic interoperability of LOINC. Methods We collected Extensional Definitions (EDs) of LOINC usage from three institutions. The version space approach was used to divide LOINC codes into small sets, which made auditing of LOINC use across the institutions feasible. We then compared pairings of LOINC codes from the three institutions for consistency and usefulness. Results The number of LOINC codes evaluated were 1,917, 1,267 and 1,693 as obtained from ARUP, Intermountain and Regenstrief respectively. There were 2,022, 2,030, and 2,301 version spaces among ARUP & Intermountain, Intermountain & Regenstrief and ARUP & Regenstrief respectively. Using the EDs as the gold standard, there were 104, 109 and 112 pairs containing contradictory knowledge and there were 1,165, 765 and 1,121 semantically interoperable pairs. The interoperable pairs were classified into three levels: 1) Level I – No loss of meaning, complete information was exchanged by identical codes. 2) Level II – No loss of meaning, but processing of data was needed to make the data completely comparable. 3) Level III – Some loss of meaning. For example, tests with a specific ‘method’ could be rolled-up with tests that were ‘methodless’. Conclusions There are variations in the way LOINC is used for data exchange that result in some data not being truly interoperable across different enterprises. To improve its semantic interoperability, we need to detect and correct any contradictory knowledge within LOINC and add computable relationships that can be used for making reliable inferences about the data. The LOINC committee should also provide detailed guidance on best practices for mapping from local codes to LOINC codes and for using LOINC codes in data exchange.

Lin, M.C.; Vreeman, D.J.; Huff, S.M.

2012-01-01

214

Direct solution of renormalization group equations of QCD in x-space: NLO implementations at leading twist  

NASA Astrophysics Data System (ADS)

We illustrate the implementation of a method based on the use of recursion relations in (Bjorken) x-space for the solution of the evolution equations of QCD for all the leading twist distributions. The algorithm has the advantage of being very fast. The implementation that we release is written in C and is performed to next-to-leading order in ?s. Program summary Title of program: evolution.c Catalogue identifier: ADUB Program summary URL: http://cpc.cs.qub.ac.uk/summaries/ADUB Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Computer: Athlon 1800 plus Operating system under which the program has been tested: Linux Programming language used: C Peripherals used: Laser printer No. of bytes in distributed program, including test data, etc.: 4559 No. of lines in distributed program, including test data, etc.: 1048 Distribution format: gzip file Nature of physical problem: The program provided here solves the DGLAP evolution equations to next-to-leading order ?s, for unpolarized, longitudinally polarized and transversely polarized parton distributions. Method of solution: We use a recursive method based on an expansion of the solution in powers of log(?s(Q)/?s(Q0)). Typical running time: About 1 minute and 30 seconds for the unpolarized and longitudinally polarized cases and 1 minute for the transversely polarized case. Permanent address.

Cafarella, Alessandro; Corianò, Claudio

2004-07-01

215

Young Stars near Earth: The Octans-Near Association and Castor Moving Group  

NASA Astrophysics Data System (ADS)

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–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–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 "Octans-Near"; 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; Song, Inseok; Schneider, Adam

2013-11-01

216

Proglucagon processing in an islet cell line: effects of PC1 overexpression and PC2 depletion.  

PubMed

Proglucagon (proG) is differentially processed in the A cells of the pancreas to yield glucagon, and in the L cells of the intestine to generate glicentin, oxyntomodulin, the incretin glucagon-like peptide (GLP)-1(7-36NH2) and the intestinotropin GLP-2. To establish roles for the prohormone convertases PC1 and PC2 in proG processing within the context of a physiological model, we created stable cell lines from an islet-derived cell line, InR1-G9. These cells express proG and PC2, but not PC1, messenger RNA (mRNA). InR1-G9 cells were stably transfected with PC1 or antisense PC2. Selection was carried out in G418 (InR1-G9/PC1) or Zeocin (InR1-G9/ASPC2). Both PC1 mRNA and protein were highly expressed in InR1-G9/PC1 cells (P < 0.01-0.001) compared with wild-type (WT) cells. Cells transfected with ASPC2 demonstrated significant decreases in both PC2 mRNA (P < 0.001) and protein (P < 0.05) levels. ProG-derived peptides in WT, control, InR1-G9/PC1, and InR1-G9/ASPC2 cells were identified by HPLC and RIA. Overexpression of PC1 in InR1-G9 cells resulted in increased processing to glicentin (P < 0.01), oxyntomodulin (P < 0.05), and GLP-2 (P < 0.05). Interestingly, processing to GLP-1(7-36NH2) did not increase upon transfection of PC1. Transfection of InR1-G9 cells with ASPC2 resulted in the disappearance of glicentin (P < 0.05). However, production of glucagon was not altered by antisense deletion of PC2. Surprisingly, GLP-1(7-36NH2) production appeared to be augmented (P < 0.05) in InR1-G9/ASPC2 cells, whereas GLP-2 production was not altered. In conclusion, these studies establish the role of PC1 in the processing of proG to the intestinal proG-derived peptides. This study also establishes a role for PC2 in the production of glicentin; however, the liberation of glucagon appears to be mediated by another, yet to be identified, convertase. PMID:9528943

Dhanvantari, S; Brubaker, P L

1998-04-01

217

A 3D balanced-SSFP Dixon technique with group-encoded k-space segmentation for breath-held non-contrast-enhanced MR angiography.  

PubMed

A three-dimensional balanced steady-state free precession (b-SSFP)-Dixon technique with a novel group-encoded k-space segmentation scheme called GUINNESS (Group-encoded Ungated Inversion Nulling for Non-contrast Enhancement in the Steady State) was developed. GUINNESS was evaluated for breath-held non-contrast-enhanced MR angiography of the renal arteries on 18 subjects (6 healthy volunteers, 12 patients) at 3.0 T. The method provided high signal-to-noise and contrast renal angiograms with homogeneous fat and background suppression in short breath-holds on the order of 20 s with high spatial resolution and coverage. GUINNESS has potential as a short breath-hold alternative to conventional respiratory-gated methods, which are often suboptimal in pediatric subjects and patients with significant diaphragmatic drift/sleep apnea. PMID:22055852

Saranathan, Manojkumar; Bayram, Ersin; Worters, Pauline W; Glockner, James F

2011-11-03

218

Observation of phycoerythrin-containing cyanobacteria and other phytoplankton groups from space using Differential Optical Absorption Spectroscopy on SCIAMACHY data  

NASA Astrophysics Data System (ADS)

In order to understand the marine phytoplankton's role in the global marine ecosystem and biogeochemical cycles it is necessary to derive global information on the distribution of major functional phytoplankton types (PFT) in the world oceans. In our study we use instead of the common ocean color sensors such as CZCS, SeaWiFS, MODIS, MERIS, with rather low spectral resolution, the Differential Optical Absorption Spectroscopy (DOAS) to study the retrieval of phytoplankton distribution and absorption with the satellite sensor Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY). SCIAMACHY measures back scattered solar radiation in the UV-Vis-NIR spectral region with a high spectral resolution (0.2 to 1.5 nm). We used in-situ measured phytoplankton absorption spectra from two different RV Polarstern expeditions where different phytoplankton groups were representing or dominating the phytoplankton composition in order to identify these characteristic absorption spectra in SCIAMACHY data in the range of 430 to 500 nm and also to identify absorption from cyanobacterial photosynthetic pigment phycoerythrin. Our results show clearly these absorptions in the SCIAMACHY data. The conversion of these differential absorptions by including the information of the light penetration depth (according to Vountas et al., Ocean Science, 2007) globally distributed pigment concentrations for these characteristic phytoplankton groups for two monthly periods (Feb-March 2004, Oct-Nov 2005 and Oct-Nov 2007) are derived. The satellite retrieved information on cyanobacteria (Synechococcus sp. and Prochlorococcus sp.) and diatoms distribution matches well with the concentration measured from collocated water samples with HPLC technique and also to global model analysis with the NASA Ocean Biogeochemical Model (NOBM from http://reason.gsfc.nasa.gov/OPS/Giovanni/) according to Gregg and Casey 2006 and Gregg 2006. Results are of great importance for global modelling of marine ecosystem and climate change studies regarding changes in the ocean.

Bracher, Astrid; Dinter, Tilman; Burrows, John P.; Vountas, Marco; Röttgers, Rüdiger; Peeken, Ilka

219

Ternary phase diagram of dipalmitoyl-PC/dilauroyl-PC/cholesterol: nanoscopic domain formation driven by cholesterol.  

PubMed Central

A ternary phase diagram is proposed for the hydrated lamellar lipid mixture dipalmitoylphosphatidylcholine/dilauroylphosphatidylcholine/cholesterol (DPPC/DLPC/cholesterol) at room temperature. The entire composition space has been thoroughly mapped by complementary experimental techniques, revealing interesting phase behavior that has not been previously described. Confocal fluorescence microscopy shows a regime of coexisting DPPC-rich ordered and DLPC-rich fluid lamellar phases, having an upper boundary at apparently constant cholesterol mole fraction chi(chol) approximately 0.16. Fluorescence resonance energy transfer experiments confirm the identification and extent of this two-phase regime and, furthermore, reveal a 1-phase regime between chi(chol) approximately 0.16 and 0.25, consisting of ordered and fluid nanoscopic domains. Dipyrene-PC excimer/monomer measurements confirm the new regime between chi(chol) approximately 0.16 and 0.25 and also show that rigidly ordered phases seem to disappear around chi(chol) approximately 0.25. This study should be considered as a step toward a more complete understanding of lateral heterogeneity within biomembranes. Cholesterol may play a role in domain separation on the nanometer scale.

Feigenson, G W; Buboltz, J T

2001-01-01

220

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

221

PC-based PCM (Pulse Code Modulation) telemetry data reduction system hardware  

SciTech Connect

The Solar Energy Research Institute's (SERI) Wind Research Program is using pulse code modulation (PCM) telemetry systems to study horizontal-axis wind turbines. SERI has developed a low-cost PC-based PCM data acquisition system to facilitate quick PCM data analysis in the field. The SERI PC-PCM system consists of AT-compatible hardware boards for decoding and combining PCM data streams and DOS software for control and management of data acquisition. Up to four boards can be installed in a single PC, providing the capability to combine data from four PCM streams direct to disk or memory. This paper describes the SERI PC-PCM system hardware, focusing on the practicality of PC-based PCM data reduction. A related paper highlights our comprehensive PCM data management software program which can be used in conjunction with this hardware to provide full quick-look'' data processing and display. The PC-PCM hardware boards support a subset of the Inter-Range Instrumentation Group (IRIG) PCM standard, designed to synchronize and decommutate NRZ or Bi-Phase L PCM streams in the range of 1 to 800 Kbits/sec at 8 to 12 bits per word and 2 to 64 words per frame. Multiple PCM streams (at various rates) can be combined and interleaved into a contiguous digital time series. Maximum data throughput depends on characteristics of the PC hardware, such as CPU rate and disk access speed. 7 refs., 6 figs., 4 tabs.

Simms, D.A.; Butterfield, C.P.

1990-02-01

222

602PC Suite 4.0  

NSDL National Science Digital Library

Developed as a suite of office products, 602PC Suite is compatible with MS Office document types, and contains four full-featured applications, including a word processor, spreadsheet, and photo editor. The word processor is compatible with MS Word, and supports multiple languages. The newest additions included in this version of 602PC Suite include advanced document format compatibility, an MS Office 2003-style toolbar, and complete support for digital photography and imaging. This edition is compatible with systems running Windows 98 and above.

223

602PC Suite 4.0  

NSDL National Science Digital Library

For those looking for an alternative to some of the more mainstream computer office suite packages, the free edition of 602PC Suite 4.0 may be worth a look. The package of programs includes a word processor, spreadsheet, photo editor, and a digital photo organizer. Additionally, this application is compatible with MS Office document types, and supports a number of different languages. The program is a bit large (approximately 21.5 MB), so those persons using a dial-up connection will want to keep this in mind. 602PC Suite 4 is compatible with all systems running Windows 98 and higher.

224

SuperComputers for Space Applications.  

National Technical Information Service (NTIS)

Upcoming new science and Earth observation projects, like GAIA, make the need for high-power computing systems more and more evident in the space community. Commercial technologies, like PowerPC processors, have very promising properties apart from their ...

G. Estaves P. Leconte G. Vissio X. Leyre

2005-01-01

225

Syntheses, structure and magnetic properties of pillared layered diphosphonates: M2(O3PC6H4PO3)(H2O)2 (M=CoII, NiII)  

NASA Astrophysics Data System (ADS)

This paper describes the hydrothermal syntheses of two isostructural metal bisphosphonates: M2(O3PC6H4PO3)(H2O)2 [M=CoII (1), NiII (2)]. Single-crystal structure determination of compound 1 revealed a pillared layered structure in which the phenyl groups connect the inorganic layers of cobalt phosphonate. Crystal data for 1: orthorhombic, space group Pnnm, a=19.306(5), b=4.8293(12), c=5.6390(14)Å, V=525.7(2)Å3, Z=2. Magnetic susceptibility data indicate that antiferromagnetic interactions are mediated in both cases.

Cao, Deng-Ke; Gao, Song; Zheng, Li-Min

2004-07-01

226

Fabrication of ZnPc/protein nanohorns for double photodynamic and hyperthermic cancer phototherapy  

PubMed Central

Multifunctionalization of carbon nanotubules is easily achieved by attaching functional molecules that provide specific advantages for microscopic applications. We fabricated a double photodynamic therapy (PDT) and photohyperthermia (PHT) cancer phototherapy system that uses a single laser. Zinc phthalocyanine (ZnPc) was loaded onto single-wall carbon nanohorns with holes opened (SWNHox), and the protein bovine serum albumin (BSA) was attached to the carboxyl groups of SWNHox. In this system, ZnPc was the PDT agent, SWNHox was the PHT agent, and BSA enhanced biocompatibility. The double phototherapy effect was confirmed in vitro and in vivo. When ZnPc-SWNHox-BSA was injected into tumors that were subcutaneously transplanted into mice, the tumors almost disappeared upon 670-nm laser irradiation. In contrast, the tumors continued to grow when only ZnPc or SWNHox-BSA was injected. We conclude that carbon nanotubules may be a valuable new tool for use in cancer phototherapy.

Zhang, Minfang; Murakami, Tatsuya; Ajima, Kumiko; Tsuchida, Kunihiro; Sandanayaka, Atula S. D.; Ito, Osamu; Iijima, Sumio; Yudasaka, Masako

2008-01-01

227

PC viruses: How do they do that.  

National Technical Information Service (NTIS)

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, comput...

K. Pichnarczyk

1992-01-01

228

Tablet PC: blackboard to the web  

Microsoft Academic Search

The use of the Tablet PC® as a lecture aid allows for the best of both worlds: the ability to present prepared lectures with well thought out graphics and the ability to annotate and develop a lecture in real time as would be done on a conventional blackboard. As classroom presentations become more computer based, they generally become less flexible

Steven J. Timmins

2004-01-01

229

Measuring Bullet Velocity with a PC Soundcard  

Microsoft Academic Search

This article describes a simple method for using a PC soundcard to accurately measure bullet velocity. The method involves placing the microphone within a foot of the muzzle and firing at a steel target between 50 and 100 yards away. The time of flight for the bullet is simply the recorded time between muzzle blast and sound of the bullet

Michael Courtney; Brian Edwards

2006-01-01

230

Stretch Your PC Dollars--Buy Clones.  

ERIC Educational Resources Information Center

Relates how the story of how San Francisco State University evaluated IBM PC look-alikes, considered some of the risks involved, and decided to purchase over 100 of them. Questions of compatibility, vendor longevity, support, and other risk management issues are discussed. (Author/MLW)

True, John

1986-01-01

231

PC based precision timing without GPS  

Microsoft Academic Search

A highly accurate monitoring solution for active network measurement is provided without the need for GPS, based on an alternative software clock for PC's running Unix. With respect to clock it's performance exceeds common GPS and NTP synchronized software clock accuracy. It is based on the TSC register counting CPU cycles and offers a resolution of around 1ns, a rate

Attila Pásztor; Darryl Veitch

2002-01-01

232

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

233

Mathematics instruction and the tablet PC  

Microsoft Academic Search

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

K. Renee Fister; Maeve L. McCarthy

2008-01-01

234

PC Kiosk Trends in Rural India  

ERIC Educational Resources Information Center

|This article presents a series of preliminary, quantitative results on rural PC kiosks in India. An analysis of the data confirms many expected trends and correlations and shows that kiosks still face the challenge of sustainability as a business. This study is based on questionnaires presented to kiosk operators and customers of kiosks operated…

Toyama, Kentaro; Kiri, Karishma; Menon, Deepak; Sethi, Suneet; Pal, Joyojeet; Srinivasan, Janaki

2006-01-01

235

Effects of oridonin nanosuspension on cell proliferation and apoptosis of human prostatic carcinoma PC-3 cell line  

PubMed Central

This study aims to investigate the inhibitory effects of oridonin nanosuspension on human prostatic carcinoma PC-3 cell line in vitro. The PC-3 cells were incubated with increasing concentrations of oridonin solution and nanosuspensions for 12 hours, 24 hours, and 36 hours. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay was performed to measure cellular viability and investigate the effect of oridonin on cell growth of PC-3. Annexin V-FITC/PI staining method was used to determine the effect of oridonin by fluorescence microscope and flow cytometry, respectively. Nanosuspension on early apoptosis of PC-3 cells was also evaluated. Oridonin significantly inhibited the growth of PC-3 cells after 12 hours, 24 hours, and 36 hours of treatment in a dose-dependent manner (P < 0.05). Compared with the same concentration of oridonin solution, oridonin nanosuspension enhanced the inhibition ratio of proliferation. The observation of propidium iodide fluorescence staining confirmed the MTT assay results. The cell proportion of PC-3 at the G2/M phase in the nanosuspension treatment group was upregulated compared with that of the control and oridonin solution groups. Both oridonin solution and nanosuspension promoted the early apoptosis of PC-3 cells. Furthermore, while improving the ratio of early apoptosis, oridonin nanosuspensions also enhanced growth suppression, and induced apoptosis of PC-3 cells. This shows great potential in the treatment of androgen-independent carcinoma of prostate by oridonin nanosuspensions.

Zhang, Zhen; Zhang, Xiumei; Xue, Wei; YangYang, Yuna; Xu, Derong; Zhao, Yunxue; Lou, Haiyan

2010-01-01

236

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

237

Realtidsklockor foer IBM PC/AT (Real Time Clocks for IBM PC/AT),  

National Technical Information Service (NTIS)

The report describes a computer card with three programmable real time clocks to be placed in Personal Computer IBM PC/AT, aimed to be used in rapid control system. An example of a program is also given.

B. Landkvist

1988-01-01

238

Estimation of the radial diffusion coefficient using REE-associated ground Pc 5 pulsations  

NASA Astrophysics Data System (ADS)

Pc 5 pulsations with frequencies between 1.67 and 6.67 mHz are believed to contribute to the REE in the outer radiation belt during magnetic storms, by means of the observations [Baker et al., 1998; Rostoker et al., 1998; Mathie and Mann, 2000; O'Brien et al., 2001, 2003] and several theoretical studies. The latter studies are roughly categorized into two themes: in-situ acceleration at L lower than 6.6 by wave-particle interactions [Liu et al., 199 9; Summers et al., 1999; Summers and Ma, 2000] and acceleration by radial diffusion from the outer to the inner magnetosphere [Elkington et al., 1999, 2003; Hudson et al., 2000; Kim et al., 2001]. One possible acceleration mechanism is the resonant interaction with Pc 5 toroidal and poloidal pulsations, referred as the radial diffusion mechanism. One of unsolved problems is where and which Pc 5 pulsation mode (toroidal and/or poloidal) play effective role in the radial diffusion process. In order to verify Pc 5 pulsation as the major roles for REEs, we have to examine the time variation of electron phase space density (cf. Green et al., 2004). Electron phase space density is not directly measured, but we can estimate radial diffusion coefficients which determine the electron transportation efficiency, using ground-based magnetic field data. We estimated the radial diffusion coefficient of ground Pc 5 pulsations associated with the Relativistic Electron Enhancement (REE) in the geosynchronous orbit. In order to estimate the radial diffusion coefficient D_LL, we need the value of in-situ Pc 5 electric field power spectral density. In this paper, however, we estimated the equatorial electric field mapped from Pc 5 pulsations power spectral density on the ground. Reciprocal of radial diffusion coefficient describes the timescale T_LL for an electron to diffuse 1 Re. Applying a superposed epoch analysis about timescales T_LL of the radial diffusion for 12 REE events in 2008, we found that when the relativistic electron enhancements occur, T_LL at higher latitude (L larger than 5) is predominantly diffusional, whereas T_LL at lower latitude (L less than 4) is mainly convectional. We concluded that higher-latitude Pc 5 pulsations play more effective roles than lower latitude Pc 5 pulsations in the radial diffusion process.

Fujimoto, A.; Yumoto, K.

2010-12-01

239

First-principles study for the adsorption of segments of BPA-PC on ?-Al2O3(0001)  

NASA Astrophysics Data System (ADS)

We have studied the adsorption of bisphenol-A-polycarbonate (BPA-PC) on the ?-Al2O3(0001) surface using density functional theory (DFT) with van der Waals (vdW) corrections. The BPA-PC polymer can be divided into its chemical fragments, which are phenylene, carbonate, and isopropylidene groups. We have calculated the adsorption energy and geometry of the BPA-PC segments that consist of two to three adjacent groups of the polymer. Our DFT results show that the adsorption is dominated by the vdW interaction. It is also important to include the interaction of nearest-neighbor groups in order to provide a realistic environment for the adsorption of the polymer onto the surface. Our results also show that the BPA-PC molecule attaches to the alumina surface via the carbonate group located in the middle of the molecule chain.

Blomqvist, Janne; Salo, Petri

2011-10-01

240

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

241

Genetic Variants of the ENPP1/PC-1 Gene Are Associated With Hypertriglyceridemia in Male Subjects  

PubMed Central

Background Hypertriglyceridemia is associated with insulin resistance, type 2 diabetes, and the metabolic syndrome. Membrane glycoprotein PC-1 (also termed ENPP1) is a direct insulin receptor inhibitor, and certain polymorphisms of the ENPP1/PC-1 gene have been associated with insulin resistance, type 2 diabetes, obesity, and diabetic complications. Methods We examined the effect of 3 ENPP1/PC-1 variants (K121Q, rs1044498, and IVS20delT-11, rs1799774, and A?G+1044TGA, rs7754561) on plasma triglyceride levels in 1112 subjects of non-Hispanic American white European ancestry. Results Two of the ENPP1/PC-1 variants—A?G+1044TGA (odds ratio [OR] 1.48, 95% confidence interval [CI], 1.54–1.82, P = 0.002) and IVS20delT-11 (OR 1.41, 95% CI, 1.08–1.84, P = 0.012)—were significantly associated with hypertriglyceridemia. Haplotype analyses also revealed an association with hypertriglyceridemia. In the variant analyses and in the haplotype analysis, the associations with hypertriglyceridemia were observed in male but not female subjects. Interestingly, the more widely studied K121Q ENPP1/PC-1 variant was not associated with hypertriglyceridemia in any group or subgroup analysis. Conclusion In the present study, we find that genetic variants of the ENPP1/PC-1 gene are associated with hypertriglyceridemia in male subjects, and may contribute to the development of the insulin resistance/metabolic syndrome in this population.

Goldfine, Ira D.

2009-01-01

242

Multi-Instrument Observations of Pc 3-4 Pulsations at Cusp Latitudes in Svalbard, Norway  

NASA Astrophysics Data System (ADS)

It has been generally accepted that Pc 3-4 pulsations (~ 10-100 mHz) originate in the ion foreshock upstream of the bow shock due to the interaction between reflected ions and the solar wind, but it is not clear how these waves propagate to the high-latitude ionosphere. Many early studies noted increased power in the vicinity of the dayside cusp. In this study, we compared signal power at Pc 3-4 frequencies from searchcoil magnetometers at three closely-spaced stations on Svalbard: Ny Alesund (76.31° Magnetic Latitude), Longyearbyen (75.26° Magnetic Latitude) and Hornsund (74.24° Magnetic Latitude). Data from the SuperDARN Finland HF radar and DMSP satellites were used to accurately locate the cusp latitudes. We found several events where magnetometers showed strong, narrow-band Pc 3-4 signals, while during the same period the SuperDARN radar saw a clear-edged cusp and a DMSP satellite passing overhead observed the typical cusp signature. We found that most of the time, the signals were strongest equatorward of the cusp, consistent not with entry via the cusp proper but along field lines equatorward of the cusp which map to the boundary layer or outer magnetosphere. Another important aspect of the Pc3 pulsations, polarization characteristics, was also statistically studied. The results show that Pc3 pulsations observed at our Svalbard stations were predominantly left-hand polarized.

Lu, F.; Engebretson, M. J.; Lessard, M. R.; Kim, H.; Wright, D.

2008-05-01

243

PC12 differentiation on biopolymer nanostructures  

NASA Astrophysics Data System (ADS)

The study of nervous system regeneration and axonal outgrowth control are relevant in several research areas, like neurophysiology or biomedical engineering. Among the elements that control neuron dynamics, the host substrate topography is a key parameter in determining cell differentiation. We present time-lapse experiments to analyze the differentiation dynamics of PC12 cells on nanopatterned biocompatible substrates. 200 nm depth gratings were fabricated on tissue-culture polystyrene substrates by nanoimprint lithography; different linewidths and pitches were compared down to 500 nm and 1000 nm, respectively. PC12 cells were cultured on these substrates and, following NGF administration to the medium, body morphology, cell movement and neuritogenesis were monitored at different time periods. In addition to demonstrating guided differentiation, our studies show complex time variations in body morphology and axon length, and guided cell movement. We show unstable synaptic connections and cell-body polarization, and the competition between topographical guidance and cell-cell interactions.

Cecchini, Marco; Bumma, Giorgia; Serresi, Michela; Beltram, Fabio

2007-12-01

244

Securing PC applications: the relay race approach  

Microsoft Academic Search

The widespread use of personal computers and the growth of end-user computing have introduced a myriad of security concerns. As PC-based information systems become readily available and more individuals become computer literate, the risk of ill-intentioned individuals obtaining unauthorized access to computing resources and violating the secrecy and integrity of data increases significantly. But many of these computer security concerns

Moshe Zviran

2002-01-01

245

SIMION for the PC in Reflection  

SciTech Connect

This article is a reflective overview of the origins, history, and capabilities of the ion optics simulation program for the PC (versions 2.0–7.0) from the author’s perspective. It provides insight into the rationale and events that contributed to the direction of the evolution and current capabilities of the program. The capabilities of version 7.0 are presented along with tests of its computational accuracy. Future developmental areas are discussed.

Dahl, David Adrian

2000-12-01

246

The PC tachistoscope has 240 pages  

Microsoft Academic Search

Myors (1998) showed how to combine familiar video page switching with bit-plane layering in video mode 0dh to increase the\\u000a capacity of the PC tachistoscope from 8 to 32 pages. The present article shows how to combine video page switching with color\\u000a page switching to implement a 240-page tachistoscope, thus producing an almost eightfold increase in the capacity of the

Brett Myors

1999-01-01

247

Human/Nonhuman Primate AC-PC Ratio - Considerations for Translational Brain Measurements  

PubMed Central

This comparative magnetic resonance imaging (MRI) analysis evaluated the ratio of AC-PC (anterior commissure to posterior commissure) distance measures in selected groups of humans and nonhuman primates (NHPs). An understanding of the basis of this ratio between primate species may allow more accurate translation of NHP stereotactic targeting measurements to upcoming human trials. MRI datasets of adult humans [n=21], and juvenile and adult NHPs (Macaca fascicularis [n=40], and Macaca mulatta [n=32]), were evaluated in a mid-sagittal plane to obtain the AC-PC distance measure for each examined subject. Two trained evaluators, blinded to each other’s results, carried out three separate measurements of the AC-PC length for each subject. Each observer carried out measurements of the entire dataset [n=93] before repeating the measurements two additional times. Previous dataset measures were not available for review at the time of subsequent measures. Inter- and intra-observer variabilities were not statistically significant. Minimal intraspecies variation was found in the AC-PC measurement of our human and NHP groups. We found significant interspecies differences, however, more between humans and NHPs, and less between the NHP groups. Regression analysis confirms the strong linear relationship of AC-PC distance based primarily on species in our study groups. Human/NHP AC-PC ratios varied between 2.1 to 2.3 based on the compared NHP species groups. We conclude that the scale differences in brain measurements between NHPs and humans described in this study allows improved translation of stereotactic targeting coordinates in future human clinical trials, which may lead to improved efficacy and safety.

Fiandaca, Massimo S.; Salegio, Ernesto Aguilar; Yin, Dali; Richardson, R. Mark; Valles, Francisco E.; Larson, Paul S.; Starr, Philip A.; Lonser, Russell R.; Bankiewicz, Krystof S.

2011-01-01

248

Spent fuel pin temperature PC code  

SciTech Connect

During an annual outage, a Pressurized Water Reactor (PWR) may discharge 60 or more spent fuel bundles into its storage pool. Most early PWRs were built to store 3 to 5 years of spent fuel in their pools and are beginning to exceed their capacities. One method currently being developed and licensed for expanding spent fuel storage capabilities is the dry storage of spent fuel in large casks. To reduce the probability of gross failures of fuel cladding during dry storage in casks, the fuel pin temperatures must be shown to remain within acceptable limits. LLNL has developed, for the Nuclear Regulatory Commission, a personal computer (PC) code for calculating fuel pin temperatures on the IBM PC. The code uses the Wooton-Epstein Correlation to calculate the pin temperatures and has been benchmarked against test data. An iterative type of solution is used to calculate the fuel pin temperatures for specified heat fluxes and pin configurations. The PC code is useful in performing confirmatory analyses and comparing the results with those submitted by applicants applying for storage licenses. 5 references, 2 tables.

Fischer, L.E.

1985-03-01

249

PC-based stereoscopic video walkthrough  

NASA Astrophysics Data System (ADS)

This paper describes a computer program which allows a user to semi-interactively navigate through a pre-recorded environment. The experience is achieved using a set of stereoscopic video sequences which have been recorded while walking around the various pathways of the chosen environment. In the completed system,the stereoscopic video sequences are played back in a sequence such that the operator is given the illusion of being able to continuously and semi-interactively navigate through the environment in stereoscopic 3D. At appropriate decision points the operator is given the option of choosing which direction to continue moving - thereby providing a level of interactivity. This paper discusses the combination of two recent advances in computer technology to transfer an existing video-disk based stereoscopic video walkthrough to run entirely on a PC. The increased computation power of PCs in recent years has allowed reasonably high-quality video playback to be performed on the desktop PC with no additional hardware. Also, Liquid Crystal Shutter (LCS) glasses systems are now widely available allowing high-quality stereoscopic images to be viewed easily on a PC. The demonstration system we have implemented interfaces with a large range of LCS glasses and allows the exploration of stereoscopic video walkthrough technology.

Woods, Andrew J.; Offszanka, Douglas; Martin, Greg

1999-05-01

250

Visualisation of the chemical space of fragments, lead-like and drug-like molecules in PubChem  

Microsoft Academic Search

\\u000a Abstract  The 4.5 million organic molecules with up to 20 non-hydrogen atoms in PubChem were analyzed using the MQN-system, which consists\\u000a in 42 integer value descriptors of molecular structure. The 42-dimensional MQN-space was visualised by principal component\\u000a analysis and representation of the (PC1, PC2), (PC1, PC3) and (PC2, PC3) planes. The molecules were organized according to\\u000a ring count (PC1, 38% of

Ruud van Deursen; Lorenz C. Blum; Jean-Louis Reymond

2011-01-01

251

A Practical Method of Solving Cutoff Coulomb Problems in Momentum Space --- Application to the Lippmann-Schwinger Resonating-Group Method and the pd Elastic Scattering ---  

NASA Astrophysics Data System (ADS)

A practical method of solving cutoff Coulomb problems of two-cluster systems in momentum space is given. When a sharply cut-off Coulomb force with a cutoff radius ? is introduced at the level of constituent particles, the two-cluster direct potential of the Coulomb force becomes in general a local screened Coulomb potential. The asymptotic Hamiltonian yields two types of asymptotic waves; one is an approximate Coulomb wave with ? in the middle-range region, and the other a free (no-Coulomb) wave in the longest-range region. The constant Wronskians of this Hamiltonian can be calculated in either region. We can evaluate the Coulomb-modified nuclear phase shifts for the screened Coulomb problem using the matching condition proposed by Vincent and Phatak for the sharply cut-off Coulomb problem. We apply this method first to an exactly solvable model of the ? ? scattering with the Ali-Bodmer potential and confirm that a complete solution is obtained with a finite ?. The stability of nuclear phase shifts with respect to the change in ? within some appropriate range is demonstrated in the ? ? resonating-group method (RGM) calculation using the Minnesota three-range force. An application to the pd elastic scattering is also discussed.

Fujiwara, Y.; Fukukawa, K.

2012-08-01

252

Design of Multichannel Counting System for IBM PC and Compatibles.  

National Technical Information Service (NTIS)

A Multichannel Counting System (MCCS), based on IBM-PC and Compatible computer systems have been designed. The MCCS consists of a Multichannel Counting System plug-in interface card (MCCS-PC) for IBM PC and compatibles and a NIMBIN module (MCCS-NB). The M...

A. Osman B. Majeed M. M. Yasin Z. Ahmad

1995-01-01

253

Teaching dynamics using interactive tablet PC instruction software  

Microsoft Academic Search

Is there an advantage of using interactive tablet PC software as opposed to more traditional teaching methods? This work is an innovative use of tablet PC technology to teach an introductory dynamics course. Each student in the classroom used a tablet PC as did the instructor. In addition to using the tablet PCs, each lecture was recorded using screen capture

David Fisher; Phillip Cornwell; Julia Williams

2007-01-01

254

Pc 1–2 and Pc 4–5 pulsations observed at a network of high-latitude stations  

Microsoft Academic Search

Analysis of magnetospheric Pc 1 and Pc 2 (in brief Pc 1-2) pulsations at a network of six northern hemisphere stations at latitudes 650-76 ø CGM shows that their average frequency decreases with increasing latitude of the station. Their maximum occurrence is at L=6-9 and 1200-1600 LT. The ionospheric ducting is weak for f < 0.3 Hz. Occasionally the Pc

T. A. Plyasova-Bakounina; J. Kangas; K. Mursula; O. A. Molchanov; A. W. Green

1996-01-01

255

Pc 1-2 and Pc 4-5 pulsations observed at a network of high-latitude stations  

Microsoft Academic Search

Analysis of magnetospheric Pc 1 and Pc 2 (in brief Pc 1-2) pulsations at a network of six northern hemisphere stations at latitudes 65°-76° CGM shows that their average frequency decreases with increasing latitude of the station. Their maximum occurrence is at L=6-9 and 1200-1600 LT. The ionospheric ducting is weak for f<0.3 Hz. Occasionally the Pc 1 intensity at

T. A. Plyasova-Bakounina; J. Kangas; K. Mursula; O. A. Molchanov; A. W. Green

1996-01-01

256

Lie Groups  

Microsoft Academic Search

\\u000a This chapter discusses problems on Lie groups, Lie algebras and homogeneous spaces. After considering some specific examples\\u000a of Lie groups and Lie algebras and some questions on them, we consider homomorphisms, Lie subgroups and Lie subalgebras, integration\\u000a on Lie groups, the exponential map exp and its differential map exp*, the adjoint representation Ad and its differential map ad, and Lie

P. M. Gadea; J. Muñoz Masqué

257

A micromachined thermal flow sensor applied to a PC mouse device  

Microsoft Academic Search

This paper reports on a new PC mouse device by the use of the micromachined thermal flow sensors. The proposed mouse contains two small flow sensors mounted in two 10-mm-diameter and 3-mm-depth spaces in order to measure its velocity and direction. When the mouse is moved in a direction, air flow is generated because the air tends to stay where

Sho Sasaki; Takeshi Fujiwara; Satoshi Nozoe; Fumihiko Sato; Koichi Imanaka; S. Sugiyama

2005-01-01

258

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.

259

Proprotein convertase PC3 is not a transmembrane protein.  

PubMed

Proprotein convertase PC3 (also known as PC1) is an endopeptidase involved in proteolytic processing of peptide hormone precursors in granules of the regulated secretory pathway of endocrine cells. Lacking any extended hydrophobic segments, PC3 was considered to be a secretory protein only peripherally attached to the granule membrane. Recently, evidence has been presented that PC3 is a transmembrane protein with a 115-residue cytoplasmic domain and a membrane-spanning segment containing eight charged amino acids [Arnaoutova, I., et al. (2003) Biochemistry 42, 10445-10455]. Here, we analyzed the membrane topology of PC3 and of a PC3 construct containing a conventional transmembrane segment of 19 leucines. Alkaline extraction was performed to assess membrane integration. Exposure to the cytosol or to the ER lumen was tested by addition of C-terminal tags for phosphorylation or glycosylation, respectively. Protease sensitivity was assayed in permeabilized cells. The results show that the C-terminus of PC3 is translocated across the endoplasmic reticulum membrane. Furthermore, the proposed transmembrane segment of PC3 and a similar one of carboxypeptidase E did not stop polypeptide translocation when inserted into a stop-transfer tester construct. PC3 is thus not a transmembrane protein. These results have implications for the mechanism of granule sorting of PC3 as well as for the topology of PC2 and carboxypeptidase E, which have been reported to span the lipid membrane by homologous charged sequences. PMID:15807527

Stettler, Hansruedi; Suri, Gregor; Spiess, Martin

2005-04-12

260

Mouse Orthotopic Lung Cancer Model Induced by PC14PE6  

PubMed Central

Purpose This study was undertaken to investigate in detail the xenograft mouse orthotopic lung cancer model induced by PC14PE6 adenocarcinoma cells. Materials and Methods Three cell doses (0.5×106; 1×106; 2×106) of PC14PE6 cells were injected into the lungs of male BALB/c nude mice by the intrathoracic injection method. The lung and other organs, including brain, liver, spleen, kidney, muscle, adrenal gland, and lymph node on knee, were removed and stained with H/E to detect the presence of tumor cells. Results The reliable tumorigenicity time in the PC14PE6 adenocarcinoma cell-inoculated BALB/c nude mouse was 10 days after intrathoracic injection. The average life span of the three groups after inoculation was 14 days in the 2×106 cells inoculum group; 25 days in the 1×106 cells inoculum group; and 32 days in the 0.5×106 cells inoculum group. The PC14PE6 adenocarcinoma cells induced orthotopic lung cancer limited within the thorax. Conclusions This orthotopic lung cancer model is an efficient cancer model with easy inoculation methods, rapid and high tumorigenicity, and simple monitoring methods for metastasis.

Cui, Zheng Yun; Ahn, Jin Seok; Lee, Jee Yun; Kim, Won Seog; Lim, Ho Yeong; Jeon, Hyun Jung; Suh, Soo Won; Kim, Jin Hoon; Kong, Won Ho; Kang, Ji Min; Nam, Do Hyun

2006-01-01

261

Amerindians show no association of PC-1 gene Gln121 allele and obesity: a thrifty gene population genetics.  

PubMed

PC-1 Gln121 gene is a risk factor for type 2 diabetes, obesity and insulin resistance in European/American Caucasoids and Orientals. We have aimed to correlate for the first time this gene in Amerindians with obesity and their corresponding individuals genotypes with obesity in order to establish preventive medicine programs for this population and also studying the evolution of gene frequencies in world populations. Central obesity was diagnosed by waist circumference perimeter and food intake independent HDL-cholesterol plasma levels were measured. HLA genes were determined in order to more objectively ascertain participants Amerindians origin. 321 Amerindian blood donors who were healthy according to the blood doning parameters were studied. No association was found between PC-1 Gln121 variant and obesity. Significant HDL-cholesterol lower values were found in the PC-1 Lys121 bearing gene individuals versus PC-1 Gln121 bearing gene ones (45.1 ± 12.7 vs. 48.7 ± 15.2 mg/dl, p < 0.05). Population analyses showed a world geographical gradient in the PC-1 Gln121 allele frequency: around 9% in Orientals, 15% in European Caucasoids and 76% in Negroids. The conclusions are: (1) No association of PC-1 Gln121 gene is found with obesity in Amerindians when association is well established in Europeans. (2) PC-1 Gln121 gene is associated to higher levels of HDL-cholesterol than the alternative PC-1 Lys121 allele. This may be specific for Amerindians. (3) Amerindians have an intermediate frequency of this possible PC-1 Gln121 thrifty gene when compared with Negroid African Americans (78.5%) or Han Chinese (7.5%, p < 0.0001). Historical details of African and other groups may support the hypothesis that PC-1 Gln121 is indeed a thrifty gene. PMID:22327785

Rey, Diego; Fernandez-Honrado, Mercedes; Areces, Cristina; Algora, Manuel; Abd-El-Fatah-Khalil, Sedeka; Enriquez-de-Salamanca, Mercedes; Coca, Carmen; Arribas, Ignacio; Arnaiz-Villena, Antonio

2012-02-12

262

Pc3 4 ULF waves at polar latitudes  

NASA Astrophysics Data System (ADS)

A search for Pc3-4 wave activity was performed using data from a trans-Antarctic profile of search-coil magnetometers extending from the auroral zone through cusp latitudes and deep into the polar cap. Pc3-4 pulsations were found to be a ubiquitous element of ULF wave activity in all these regions. The diurnal variations of Pc3 and Pc4 pulsations at different latitudes have been statistically examined using discrimination between wave packets (pulsations) and noise. Daily variations of the Pc3-4 wave power differ for the stations at the polar cap, cusp, and auroral latitudes, which suggests the occurrence of several channels of propagation of upstream wave energy to the ground: via the equatorial magnetosphere, cusp, and lobe/mantle. An additional maximum of Pc3 pulsations during early-morning hours in the polar cap has been detected. This maximum, possibly, is due to the proximity of the geomagnetic field lines at these hours to the exterior cusp. The statistical relation between the occurrence of Pc3-4 pulsations and interplanetary parameters has been examined by analyzing normalized distributions of wave occurrence probability. The dependences of the occurrence probability of Pc3-4 pulsations on the IMF and solar wind parameters are nearly the same at all latitudes, but remarkably different for the Pc3 and Pc4 bands. We conclude that the mechanisms of high-latitude Pc3 and Pc4 pulsations are different: Pc3 waves are generated in the foreshock upstream of the quasi-parallel bow shock, whereas the source of the Pc4 activity is related to magnetospheric activity. Hourly Pc3 power has been found to be strongly dependent on the season: the power ratio between the polar summer and winter seasons is ~8. The effect of substantial suppression of the Pc3 amplitudes during the polar night is reasonably well explained by the features of Alfven wave transmission through the ionosphere. Spectral analysis of the daily energy of Pc3 and Pc4 pulsations in the polar cap revealed the occurrence of several periodicities. Periodic modulations with periods 26, 13 and 8-9 days are caused by similar periodicities in the solar wind and IMF parameters, whereas the 18-day periodicity, observed during the polar winter only, is caused, probably, by modulation of the ionospheric conductance by atmospheric planetary waves. The occurrence of the narrow-band Pc3 waves in the polar cap is a challenge to modelers, because so far no band-pass filtering mechanism on open field lines has been identified.

Pilipenko, V. A.; Chugunova, O. M.; Engebretson, M. J.

2008-12-01

263

Motor Proteins at Work in PC12  

NASA Astrophysics Data System (ADS)

Motor proteins such as kinesin and dynein drive vesicle transport within cells by converting the chemical energy of ATP into mechanical work. As vesicles are transported in PC12 neurites, they travel at constant velocity for long intervals before changing to a different constant velocity. When scaled by the minimum observed velocity of a vesicles, the changes in velocity occur in quantizes intervals of +/- 1, 2, 3 etc. These changes in velocity are caused by a change in the number of motor proteins actively transporting the vesicle. The viscoelastic modulus and viscosity appropriate for large vesicles (0.25 - 0.5 micron radius) in PC12 was determined by measuring the Brownian motion of vesicles within the distal expansions of neurites. The corresponding Stokes' drag on the vesicles was 4.2 +/- 0.6 pN per motor. Assuming that kinesin hydrolyzes 1 ATP per 8 nm step (consistent with in-vitro measurements), the motor's efficiency is 33apply forces in magnetic beeds in the hopes of mimicking vesicle motion.

Hill, David; Holzwarth, George; Superfine, Richard

2003-11-01

264

Direccionado virtual de puertos para PC. (Port virtual addressing for PC).  

National Technical Information Service (NTIS)

Instruments for nuclear signal measurements based on add-on card for a personal computer (PC) are designed often. Then one faces the problem of the addressing of data input/output devices which show an integration level or intelligence that makes the use ...

L. Bolanos E. Arista J. F. Osorio Deliz

1997-01-01

265

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).  

National Technical Information Service (NTIS)

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 be...

1976-01-01

266

Defective prodynorphin processing in mice lacking prohormone convertase PC2.  

PubMed

Prodynorphin, a multifunctional precursor of several important opioid peptides, is expressed widely in the CNS. It is processed at specific single and paired basic sites to generate various biologically active products. Among the prohormone convertases (PCs), PC1 and PC2 are expressed widely in neuroendocrine tissues and have been proposed to be the major convertases involved in the biosynthesis of hormonal and neural peptides. In this study we have examined the physiological involvement of PC2 in the generation of dynorphin (Dyn) peptides in mice lacking active PC2 as a result of gene disruption. Enzymological and immunological assays were used to confirm the absence of active PC2 in these mice. The processing profiles of Dyn peptides extracted from brains of these mice reveal a complete lack of Dyn A-8 and a substantial reduction in the levels of Dyn A-17 and Dyn B-13. Thus, PC2 appears to be involved in monobasic processing, leading to the generation of Dyn A-8, Dyn A-17, and Dyn B-13 from prodynorphin under physiological conditions. Brains of heterozygous mice exhibit only half the PC2 activity of wild-type mice; however, the levels of Dyn peptides in these mice are similar to those of wild-type mice, suggesting that a 50% reduction in PC2 activity is not sufficient to significantly reduce prodynorphin processing. The disruption of the PC2 gene does not lead to compensatory up-regulation in the levels of other convertases with similar substrate specificity because we find no significant changes in the levels of PC1, PC5/PC6, or furin in these mice as compared with wild-type mice. Taken together, these results support a critical role for PC2 in the generation of Dyn peptides. PMID:10987860

Berman, Y; Mzhavia, N; Polonskaia, A; Furuta, M; Steiner, D F; Pintar, J E; Devi, L A

2000-10-01

267

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

2008-06-11

268

Upstream-generated Pc3 ULF wave signatures observed near the Earth's cusp  

NASA Astrophysics Data System (ADS)

Pc3 pulsations (frequency ˜20-100 mHz) which originate in the ion foreshock upstream of the Earth's bow shock due to the interaction between reflected ions and the solar wind are frequently observed in ground-based pulsation magnetometer data. Previous studies have noted increased Pc3 wave power in the vicinity of the dayside cusp and inferred that the upstream waves gained entry via the cusp, although more recent studies have revealed a more complex picture. Here, we examine Pc3 wave power near local noon observed by search coil magnetometers at three closely-spaced stations on Svalbard, during times when an extended interval of HF radar backscatter indicative of the cusp is detected by the Hankasalmi SuperDARN radar. The location of the equatorward edge of the HF radar cusp may then be directly compared with the Pc3 wave power measured at three latitudes as the cusp migrates across the stations on a statistical basis. These observations are more consistent with wave entry to the magnetosphere along closed field lines equatorward of the cusp via the ionospheric transistor mechanism of Engebretson et al. (1991a), or weakly coupled fast and Alfvén wave modes, which then map to the low-latitude boundary layer or outer magnetosphere, rather than with wave entry into the magnetosphere via the cusp proper or exterior cusp.

Yeoman, T. K.; Wright, D. M.; Engebretson, M. J.; Lessard, M. R.; Pilipenko, V. A.; Kim, H.

2012-03-01

269

Electrical parameters and gas sensing behaviour of ClInPc thin film devices  

NASA Astrophysics Data System (ADS)

The electrical characteristics of thermally evaporated Chloroindium phthalocyanine thin films (ClInPc) are studied. A number of parameters are evaluated on the basis of the theory of space-charge-limited conduction. ClInPc thin films are extremely stable, in terms of both resistance to chemical attack and thermally, no hysteretic was observed after temperature cycling between room temperature and 500 K. DC current-voltage and current-temperature characteristics were obtained for ClInPc in vacuum and on exposure to dry air (20% O{2}) in both the dark and under illumination with visible light. The conductivity data were analysed in the framework of band theory to elucidate information about the activation energy Eac, forbidden band gap (E_c-E_v), domain or acceptor energy levels (E_e, E_h). In the present work we also examine the response of ClInPc to O{2} and NO{2} at different temperatures.

Azimaraghi, M. E.; Campbell, D.

2008-07-01

270

Neuronal cell lines expressing PC5, but not PC1 or PC2, process Pro-CCK into glycine-extended CCK 12 and 22.  

PubMed

Endocrine tumor cells in culture and in vitro cleavage assays have shown that PC1 and PC2 are capable of processing pro-CCK into smaller, intermediate and final, bioactive forms. Similar studies have shown that PC5 has the ability to process a number of propeptides. Here, we use GT1-7 (mouse hypothalamic) and SK-N-MC and SK-N-SH (human neuroblastoma) tumor cell lines to study the ability of PC5 to process pro-CCK. RT-PCR and Western blot analysis showed that the cells express PC5 mRNA and protein, but not PC1 or PC2. They were engineered to stably overexpress CCK and cell media was analyzed for pro-CCK expression and cleavage of the prohormone. Radioimmunoassays showed that pro-CCK was expressed, but no amidated CCK was detected. Lack of production of amidated CCK may be due to the lack of the appropriate carboxypeptidase and amidating enzymes. Production of glycine-extended CCK processing products was evaluated by treatment of media with carboxypeptidase B followed by analysis with a CCK Gly RIA. Glycine-extended forms of the peptide were found in the media. The predominant forms co-eluted with CCK 12 Gly and CCK 22 Gly on gel filtration chromatography. The results demonstrate that these cell lines which express PC5 and not PC1 or PC2 have the ability to process pro-CCK into intermediate, glycine-extended forms more closely resembling pro-CCK products in intestine than in brain. PMID:11457520

Cain, B M; Vishnuvardhan, D; Beinfeld, M C

2001-08-01

271

ncRNA- and Pc2 Methylation-Dependent Gene Relocation between Nuclear Structures Mediates Gene Activation Programs  

PubMed Central

Summary Although eukaryotic nuclei contain distinct architectural structures associated with noncoding RNAs (ncRNAs), their potential relationship to regulated transcriptional programs remains poorly understood. Here, we report that methylation/demethylation of Polycomb 2 protein (Pc2) controls relocation of growth control genes between Polycomb bodies (PcGs) and interchromatin granules (ICGs) in response to growth signals. This movement is the consequence of binding of methylated and unmethylated Pc2 to the ncRNAs, TUG1 and MALAT1/NEAT2, located in PcGs and ICGs, respectively. These ncRNAs mediate assembly of multiple co-repressors/co-activators, and can alter the histone marks read by Pc2 in vitro. Additionally, binding of NEAT2 to unmethylated Pc2 promotes E2F1 SUMOylation, leading to activation of the growth control gene program. These observations delineate a molecular pathway linking the actions of subnuclear structure-specific ncRNAs and non-histone protein methylation to relocation of transcription units in the three-dimensional space of the nucleus, thus achieving coordinated gene expression programs.

Yang, Liuqing; Lin, Chunru; Liu, Wen; Zhang, Jie; Ohgi, Kenneth A.; Grinstein, Jonathan D.; Dorrestein, Pieter C.; Rosenfeld, Michael G.

2011-01-01

272

Comprehensive Geostatistical Technology on PC Platform  

SciTech Connect

Geostatistics has attracted the attention of many earth scientist and engineers who need better modeling tools for natural gas reservoirs. Two years ago Correlations Company responded to this need through the peer reviewed, DOE Small Business Innovative Research program to develop a fractal algorithm for interpolating between measurements and mapping the consequences. During the two years research period Correlations Company has combined geostatistical modeling with high quality graphics to produce Gviz. This software provides accurate 3D reservoir modeling tools and high quality 3D graphics for PC platforms enabling engineers and geologists to better comprehend reservoirs and consequently improve their decisions. Until recently geostatistical modeling was only available to the limited number of earth scientist familiar with UNIX based platforms. Gviz runs on any PC with Windows 95 or Windows NT operating system. The Gviz pre- processing module reads LAS and ASCII files. The pre-processing module facilitates selection of the stratigraphic units prior to processing by a nearest neighbor, kriging and co-kriging, conditional simulation, or fractal module. A user friendly GUI simplifies the examination of the statistical data and the geostatistical analyses using isotropic and anisotropic variograms. After completing the analyses, the post-processing unit can generate ID models of well logs, 2D models such as cross-sections, or a 3D model of any petrophysical property. Post- processing includes the display of reservoir slices, multiple cross-sections, rotation along any axis, and identification of geobodies (visually inspect the effect of porosity cutoffs on connected pore volume). The post-processor includes an up-scaling module to transform a fine scale grid into a reservoir simulation grid which can then be exported in an Eclipse format. Gviz emphasizes a self-explanatory GUI and visually oriented help pages which guides even a novice through the process of generating realistic, two to five million cell, 3D reservoir models. Beta testing of Gviz will finish in April 1997 and a working version of the PC software package, at one fifth of the cost of a comparable UNIX system, will be available to domestic gas and oil producers in mid-1997.

Stevenson, C.

1997-10-01

273

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

Microsoft Academic Search

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

Lier

1985-01-01

274

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

275

Rheological Properties and Morphology of PC\\/AES Blends  

Microsoft Academic Search

Blends of polycarbonate (PC) and acrylonitrile–EPDM (ethylene\\/propylene\\/diene elastomer)–styrene terpolymer (AES) were prepared at 20%, 30%, 40%, 50%, and 80% by weight of AES. The rheological properties and morphology of the PC, AES, and their blends were studied systematically. The strain sweep results show that the linear viscoelastic region of the AES is far less than that of PC. With the

Bo Liu; Yong Zhang; Chaoying Wan; Wenjuan Shou; Yinxi Zhang; Yu Su; Jiliang Ji

2006-01-01

276

A prototype for simulation of the space-to-ground assembly/contingency system of Space Station Freedom  

NASA Astrophysics Data System (ADS)

This project was a continuation of work started during the Summer of 1991 when techniques and methods were investigated for simulating equipment components of the Communications and Tracking System on Space Station Freedom (SSF). The current work involved developing a design for simulation of the entire Assembly/Contingency Subsystem (ACS), which includes the Baseband Signal Processor, standard TDRSS Transponder and the RF Group antenna assembly. A design prototype of the ACS was developed. Methods to achieving 'high fidelity' real-time simulations of the ACS components on IBM-PC compatible computers were considered. The intention is to have separate component simulations running on separate personal computers (PC's), with the capability of substituting actual equipment units for those being simulated when such equipment becomes available for testing. To this end, a scheme for communication between the various simulated ACS components was developed using the serial ports of the PC's hosting the simulations. In addition, control and monitoring of ACS equipment on SSF will be via a MIL-STD 1553B bus. The proposed simulation includes actual 1553B hardware as part of the test bed.

Deacetis, Louis A.

1992-12-01

277

Cholesterol dependent recruitment of di22:6-PC by a G protein-coupled receptor into lateral domains.  

PubMed Central

Bovine rhodopsin was reconstituted into mixtures of didocosahexaenoylphosphatidylcholine (di22:6-PC), dipalmitoylphosphatidylcholine (di16:0-PC), sn-1-palmitoyl-sn-2-docosahexaenoylphosphatidylcholine (16:0, 22:6-PC) and cholesterol. Rhodopsin denaturation was examined by using high-sensitivity differential scanning calorimetry. The unfolding temperature was increased at lower levels of lipid unsaturation, but the highest temperature was detected for native disk membranes: di22:6-PC < 16:0,22:6-PC < di16:0,18:1-PC < native disks. The incorporation of 30 mol% of cholesterol resulted in 2-4 degrees C increase of denaturation temperature in all reconstituted systems examined. From the analysis of van't Hoff's and calorimetric enthalpies, it was concluded that the presence of cholesterol in di22:6-PC-containing bilayers induces a level of cooperativity in rhodopsin unfolding. Fluorescence resonance energy transfer (FRET), using lipids labeled at the headgroup with pyrene (Py) as donors and rhodopsin retinal group as acceptor of fluorescence, was used to study rhodopsin association with lipids. Higher FRET efficiencies detected for di22:6-PE-Py, compared to di16:0-PE-Py, in mixed di22:6-PC-di16:0-PC-cholesterol bilayers, indicate preferential segregation of rhodopsin with polyunsaturated lipids. The effective range of the rhodopsin-lipid interactions facilitating cluster formation exceeds two adjacent lipid layers. In similar mixed bilayers containing no cholesterol, cluster formation was absent at temperatures above lipid phase transition, indicating a crucial role of cholesterol in microdomain formation.

Polozova, A; Litman, B J

2000-01-01

278

Soviet space  

NASA Astrophysics Data System (ADS)

A profusely illustrated history of the Soviet space program is presented. The topics addressed include: early Soviet rockets, satellites and planetary probes, cosmonauts in space, space stations, international cooperation in space, and the Soviet space program today and tomorrow.

Miller, Jay

279

Electronic properties of CuPc and H2Pc: an experimental and theoretical study.  

PubMed

Phthalocyanine (H2Pc) and its open-shell copper complex (CuPc) deposited on amorphous gold films have been studied by combining the outcomes of several synchrotron based spectroscopic tools (X-ray photoelectron spectroscopy, UV photoelectron spectroscopy and near-edge X-ray absorption fine structure, NEXAFS, spectroscopy) with those of density functional theory (DFT) calculations. The assignment of experimental evidence has been guided by the results of DFT numerical experiments carried out on isolated molecules. With specific reference to CuPc NEXAFS data collected at the N K-edge, they have been assigned by using the open-shell time-dependent DFT (TDDFT) in the framework of the zeroth order regular approximation (ZORA) scalar relativistic approach. The agreement between theory and experiment has been found to be satisfactory, thus indicating that the open-shell TDDFT (F. Wang and T. Ziegler, Mol. Phys., 2004, 102, 2585) may be used with some confidence to look into the X-ray absorption spectroscopy results pertinent to transition metal complexes. As far as the metal-ligand interaction is concerned, the combined use of NEXAFS spectroscopy and DFT outcomes ultimately testified the significant ionic contribution characterizing the bonding between the metal centre and the nitrogen atoms of the phthalocyanine coordinative pocket. PMID:23807700

Nardi, Marco Vittorio; Detto, Francesca; Aversa, Lucrezia; Verucchi, Roberto; Salviati, Giancarlo; Iannotta, Salvatore; Casarin, Maurizio

2013-08-21

280

Phthalocyanine dimers in a blend: Spectroscopic and theoretical studies of MnPc? +/F16CoPc? -  

NASA Astrophysics Data System (ADS)

We have prepared mixed phthalocyanine films out of MnPc and F16CoPc, which were characterized by means of photoemission spectroscopy and electron energy-loss spectroscopy. Our data reveal the formation of MnPc/F16CoPc charge transfer dimers in analogy to the related heterojunction. The electronic excitation spectrum of these blends is characterized by a new low energy excitation at 0.6 eV. Density functional theory calculations show that the new signal is caused by a strong absorption between the states of the interface induced two level system.

Lindner, Susi; Mahns, Benjamin; König, Andreas; Roth, Friedrich; Knupfer, Martin; Friedrich, Rico; Hahn, Torsten; Kortus, Jens

2013-01-01

281

Reversible hydrocarbon activation by rhodium phthalocyanine dimer [(R[sub 8]Pc)Rh][sub 2] (R[sub 8]Pc[sup 2[minus  

SciTech Connect

We have synthesized four rhodium-phthalocyanine complexes: (R[sub 8]Pc)(C[sub 6]H[sub 5]CN)CIRh, [(R[sub 8]-Pc)(MeOH)[sub 2]Rh]Cl, [(R[sub 8]Pc)Rh][sub 2](1), and (R[sub 8]PcH)RhRh(R[sub 8]Pc)H (2). In this notation R[sub 8]Pc[sup 2[minus

Chen, M.J.; Rathke, J.W. (Argonne National Lab., IL (United States))

1994-12-01

282

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

283

Prokineticin Receptor 1 Antagonist PC-10 as a Biomarker for Imaging Inflammatory Pain  

PubMed Central

Prokineticin receptor 1 (PKR1) and its ligand Bv8 were shown to be expressed in inflammation-induced pain and by tumor-supporting fibroblasts. Blocking this receptor might prove useful for reducing pain and for cancer therapy. However, there is no method to quantify the levels of these receptors in vivo. Methods A nonpeptidic PKR1 antagonist, N-{2-[5-(4-fluoro-benzyl)-1-(4-methoxy-benzyl)-4,6-dioxo-1,4,5,6-tetrahydro-[1,3,5] triazin-2-ylamino]-ethyl}-guanidine, which contains a free guanidine group, was labeled with 18F by reacting the guanidine function with N-succinimidyl-4-18F-fluorobenzoate to give the guanidinyl amide N-(4-18F-fluoro-benzoyl)-N?-{2-[5-(4-fluoro-benzyl)-1-(4-methoxy-benzyl)-4,6-dioxo-1,4,5,6-tetrahydro-[1,3,5] triazin-2-ylamino]-ethyl}-guanidine (18F-PC-10). Inflammation was induced in C57BL/6 mice by subcutaneous injection of complete Freund adjuvant in the paw. The mice were imaged with 18F-PC-10, 18F-FDG, and 64Cu-pyruvaldehyde bis(4-methyl-3-thiosemicarbazone) (64Cu-PTSM) at 24 h after complete Freund adjuvant injection using a small-animal PET device. Results 18F-PC-10 was synthesized with a radiochemical yield of 16% ± 3% (decay-corrected). 18F-PC-10 accumulated specifically in the inflamed paw 4- to 5-fold more than in the control paw. Compared with 18F-PC-10, 18F-FDG and 64Cu-PTSM displayed higher accumulation in the inflamed paw but also had higher accumulation in the control paw, demonstrating a reduced signal-to-background ratio. 18F-PC-10 also accumulated in PKR1-expressing organs, such as the salivary gland and gastrointestinal tract. Conclusion 18F-PC-10 can be used to image PKR1, a biomarker of the inflammation process. However, the high uptake of 18F-PC-10 in the gastrointestinal tract, due to specific uptake and the metabolic processing of this highly lipophilic molecule, would restrict its utility.

Jacobson, Orit; Weiss, Ido D.; Niu, Gang; Balboni, Gianfranco; Congiu, Cenzo; Onnis, Valentina; Kiesewetter, Dale O.; Lattanzi, Roberta; Salvadori, Severo; Chen, Xiaoyuan

2013-01-01

284

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

285

Regulation of prohormone convertase 1 (PC1) by thyroid hormone.  

PubMed

The prohormone convertases (PCs) PC1 and PC2 are key enzymes capable of processing a variety of prohormones to their bioactive forms. In this study, we demonstrated that 6-n-propyl-2-thiouracil (PTU)-induced hypothyroidism stimulated, whereas triido-L-thyronine (T(3))-induced hyperthyroidism suppressed, PC1 mRNA levels in the rat anterior pituitary. Using 5' deletions of the human PC1 (hPC1) promoter transiently transfected into GH3 (a somatotroph cell line) cells, we found that T(3) negatively regulated hPC1 promoter activity and that this regulation required the region from -82 to +19 bp relative to the transcription start site. Electrophoretic mobility shift assays (EMSAs) using purified thyroid hormone receptor-alpha1 (TR alpha 1) and retinoid X receptor-beta (RXRbeta) proteins and GH3 nuclear extracts demonstrated that the region from -10 to +19 bp of the hPC1 promoter bound TR alpha 1 as both a monomer and a homodimer and bound TR alpha 1/RXR beta as a heterodimer and multimer. EMSAs with oligonucleotides containing point mutations of the putative negative thyroid response elements (TREs) exhibited diminished homodimer and loss of multimer binding. We conclude that there are multiple novel TRE-like sequences in the hPC1 promoter located from -10 to +19 bp. PMID:11120670

Li, Q L; Jansen, E; Brent, G A; Friedman, T C

2001-01-01

286

Logic verification methodology for PowerPC microprocessors  

Microsoft Academic Search

The PowerPC logic verification methodology is a gen- eral purpose approach suitable for a large class of chip designs that can exceed five million transistors in size. Several validation techniques are integrated into an automated logic verification strategy. The success of this methodology has been demonstrated by realizing three PowerPC microprocessor chips that were func- tional the first time. I.

Charles H. Malley; Max Dieudonné

1995-01-01

287

A PC104 Multiprocessor DSP System for Radiation Spectroscopy Applications  

Microsoft Academic Search

A multiprocessor DSP system hosted in a PC104 Windows CE industrial PC is presented. It is based on a master floating point Digital Signal Processor (DSP), a scalable number of slave DSPs and, special purpose trigger, pulse locator and data routing digital circuits. Although this architecture, as well as the data acquisition block, has been optimized to accommodate high throughput

J. Basílio Simões; João Cardoso; Nuno Cruz; Carlos M. B. A. Correia

288

Vibrotactile sense and mechanical functional state of the arm and hand among computer users compared with a control group  

Microsoft Academic Search

Objectives: To measure sensory perception and mechanical muscle function of the arm among experienced female computer users with (+sPC) and without (-sPC) symptoms compared with a control group (ctrl). Methods: Group +sPC had severe symptoms in the hand\\/wrist and\\/or the forearm\\/elbow region. They worked with the computer 75% and used a computer mouse 50% of the working day. Group -sPC

B. R. Jensen; M. Pilegaard; A. Momsen

2002-01-01

289

Pc 3-4 Pulsations Near the Cusp: Latitude dependence near the open-closed field line boundary  

NASA Astrophysics Data System (ADS)

Dayside ground magnetometer records at high latitudes frequently show evidence of Pc 3-4 pulsations (f ~ 10-100 mHz) which originate in the ion foreshock upstream of the Earth's bow shock due to the interaction between reflected ions and the solar wind. Previous studies have noted increased Pc 3-4 wave power in the vicinity of the dayside cusp and inferred that the upstream waves gained entry via the cusp, although more recent studies have revealed a more complex picture. Here, we examine Pc3-4 wave power near local noon observed by search coil magnetometers at three closely-spaced stations on Svalbard. Three intervals are chosen when the upstream conditions are favourable for Pc3-4 generation, clear band-limited Pc3-4 wave power is observed near local noon, and an extended interval of HF radar backscatter indicative of the cusp is detected by the Hankasalmi SuperDARN radar. A stereo mode of radar operation is employed, such that 3 s time resolution is available on one radar beam, whilst the high latitude convection is revealed with 1 min. resolution. The location of the equatorward edge of the HF radar cusp may then be directly compared with the Pc3-4 wave power measured at three latitudes as the cusp migrates across the stations. The radar data show clear evidence of transient ionospheric flows and high spectral widths associated with field lines newly- opened by dayside reconnection processes, but no evidence of oscillations in the Pc3-4 frequency range. In the ground magnetic field a peak in Pc3-4 power is generally observed in the equatormost magnetometer, except when the cusp is significantly poleward of the stations, consistent with a peak in wave power ~4 degrees equatorward of the cusp, but suggesting a modest dependence of wave power with latitude on closed field lines When the cusp does move equatorward of the magnetometer stations the Pc3-4 power drops rapidly, and does so earliest at the most poleward magnetometer station, suggesting a sharp drop in wave power when the open field line region is reached. This behaviour is confirmed by comparison of Pc3-4 wave power recorded at Svalbard with that recorded at lower latitudes at Halley Bay in Antarctica. These observations are not consistent with entry via the cusp proper, but rather along closed field lines equatorward of the cusp which map to the low-latitude boundary layer or outer magnetosphere.

Yeoman, T. K.; Wright, D. M.; Clausen, L. B.; Engebretson, M.; Lu, F.; Posch, J.; Lessard, M.; Kim, H.

2008-12-01

290

Space group and hydrogen positions of single crystal delta-AlOOH, (Al0.84Mg0.07Si0.09)H0.98O2 and its relation to stishovite and brucite  

NASA Astrophysics Data System (ADS)

A single crystal of ?-AlOOH synthesized by Suzuki et al. (2000) at conditions of 1000^oC and 21 GPa was used in this study. A set of X-ray diffraction intensities up to sin?/?=0.80 Å-1 were measured with a single crystal of 83×35×24 ?m using MoK? radiation (50 kV, 40 mA). Al:Mg:Si ratio 0.84:0.07:0.09 measured by EDS with the same crystal used in the X-ray diffraction intensity measurement yielded the chemical formula (Al0.84Mg0.07Si0.09)H0.98O_2. Suzuki et al. (2000) reported the space group P2_1nm from powder X-ray data but the systematic absence of reflections observed in this study indicated another space group Pnn2. The systematic absence of reflections observed in the present work were h+l odd for h0l and k+l odd for 0kl, indicating possible space group Pnn2 or Pnnm. The N(Z) test for a center of symmetry indicated an acentric space group. The non-centrosymmetric space group Pnn2 was therefore employed and was confirmed by the structural refinement. The agreement factors for 109 independent reflections (Io>= 3.0? Io) were R=3.6% with anisotropic temperature factors. The difference Fourier synthesis was calculated and two significant Fourier peaks H1 and H2 for the possible hydrogen sites were found. The H1 site locates around two-fold rotation axis with H1-H1 distance of 0.55 Å. The H1 site is considered to be for symmetrical statistical distribution of hydrogen atoms. The H2-H2 are separated with H2-H2 distance 2.12 Å which is larger than the sum of van der Waals radii of hydrogen atoms. The partial occupancy of Mg and Si atoms at Al site suggests the possibility of limited solid solution among ?-AlOOH, stishovite SiO_2 and hypothetical rutile-structured Mg(OH)_2. The H1 site is considered to be for AlOOH and the H_2 site for Mg(OH)_2.

Kudoh, Y.; Kuribayashi, T.; Suzuki, A.; Ohtani, E.; Kamada, T.

2003-04-01

291

PcG Proteins, DNA Methylation, and Gene Repression by Chromatin Looping  

Microsoft Academic Search

Many DNA hypermethylated and epigenetically silenced genes in adult cancers are Polycomb group (PcG) marked in embryonic stem (ES) cells. We show that a large region upstream (?30 kb) of and extending ?60 kb around one such gene, GATA-4, is organized—in Tera-2 undifferentiated embryonic carcinoma (EC) cells—in a topologically complex multi-loop conformation that is formed by multiple internal long-range contact

Vijay K Tiwari; Kelly M McGarvey; Julien D. F Licchesi; Joyce E Ohm; James G Herman; Dirk Schübeler; Stephen B Baylin

2008-01-01

292

Prohormone convertases (PC1/3 and PC2) in rat and human pancreas and islet cell tumors: subcellular immunohistochemical analysis.  

PubMed

Prohormone convertase 1/3 (PC1/3; also termed PC1 or PC3) and PC2 are enzymes that activate prohormones by cleaving the pairs of basic amino acids. This mechanism was initially inferred from the series of several endocrine and neuroendocrine precursor proteins, including proinsulin and proglucagon. To determine the cellular and subcellular distribution of PC1/3 and PC2 in the rat and human pancreas, immunohistochemistry was performed using polyclonal antisera against mouse PC1/3 (ST-28) and mouse PC2 (ST-29). These studies showed light and electron microscopic co-localization of insulin, PC1/3 and PC2, and the coexistence of glucagon and PC2 in the pancreatic islets. This tendency of colocalization was also depicted in one case of human insulinoma and three cases of human glucagonomas, as well as in rat insulinomas. In two cases of human insulinomas, incomplete processing of proinsulin was suggested by the absence of PC2. At the subcellular level in the rat pancreatic islet, the colocalization of PC1/3 and insulin, and that of PC2 and glucagon, were observed in the same secretory granules by immunoelectron microscopy and image analysis. These studies suggest that PC1/3 and PC2 can function with the specificities in the processing of proinsulin and proglucagon into their active forms, respectively, in the normal and neoplastic pancreatic islets. PMID:8916141

Itoh, Y; Tanaka, S; Takekoshi, S; Itoh, J; Osamura, R Y

1996-10-01

293

Cluster analysis of the DrugBank chemical space using molecular quantum numbers.  

PubMed

DrugBank (>6000 approved and experimental drugs) was analyzed using molecular quantum numbers (MQNs), which are 42 integer value descriptors of molecular structure counting atoms, bonds, polar groups and topological features. Principal component analysis of MQN-space showed that drugs differ mostly by size (PC1, 67% variance) and structural rigidity and polarity (PC2, 18% variance). Twenty-eight groups of target specific drugs were recovered by proximity sorting in MQN-space as efficiently as by substructure fingerprint (SF) similarity, but in different order allowing for lead-hopping relationships not seen in SF similarity. Clustering by MQN- or SF-similarity produced very different types of clusters. Each of the 28 drug groups spread over different clusters in both MQN- and SF-clustering, and most clusters contained drugs from different target specific groups, showing that structure-based classifications only partially overlap with bioactivity. An MQN-browsable version of DrugBank is available at www.gdb.unibe.ch. PMID:22465859

Awale, Mahendra; Reymond, Jean-Louis

2012-03-14

294

A closer look at main belt asteroids 1: WF/PC images  

NASA Astrophysics Data System (ADS)

We present new reconstructions of images of main belt Asteroids 9 Metis, 18 Melpomene, 19 Fortuna, 216 Kleopatra, and 624 Hektor, made with the uncorrected Wide-Field/Planetary Camera (WF/PC) on the Hubble Space Telescope (HST). Deconvolution with the MISTRAL algorithm demonstrates that these asteroids are clearly resolved. We determine diameters, albedos, and lower limits to axial ratios for these bodies. We also review the process used to restore the aberrated images. No surface features or companions are found, but the rotation of 216 Kleopatra is clearly seen. The asteroidal albedos are similar to those determined by other procedures.

Storrs, A. D.; Dunne, C.; Conan, J.-M.; Mugnier, L.; Weiss, B. P.; Zellner, B.

2005-02-01

295

Multi-Instrument Observations of Pc 3-4 Pulsations at Cusp Latitudes in Svalbard, Norway  

NASA Astrophysics Data System (ADS)

It has been generally accepted that Pc 3-4 pulsations (~ 10-100 mHz) originate in the ion foreshock upstream of the bow shock due to the interaction between reflected ions and the solar wind, but it is not clear how these waves propagate to the high-latitude ionosphere. Many early studies noted increased power in the vicinity of the dayside cusp. In this study, we compared signal power at Pc 3-4 frequencies from searchcoil magnetometers at three closely-spaced stations on Svalbard: Ny Alesund (76.31o Magnetic Latitude), Longyearbyen (75.26o Magnetic Latitude) and Hornsund (74.24o Magnetic Latitude). Data from the SuperDARN Finland HF radar and DMSP satellites were used to accurately locate the cusp latitudes. We found several events where magnetometers showed strong, narrow-band Pc 3-4 signals, while during the same period the SuperDARN radar saw a clear-edged cusp and a DMSP satellite passing overhead observed the typical cusp signature. We found that often the wave packets were localized and linearly polorized. Also most of the time, the signals were strongest equatorward of the cusp, consistent not with entry via the cusp proper but along field lines equatorward of the cusp which map to the boundary layer or outer magnetosphere.

Lu, F.; Engebretson, M.; Lessard, M.; Kim, H.; Wright, D.

2007-12-01

296

Palytoxin causes nonoxidative necrotic damage to PC12 cells in culture.  

PubMed

Palytoxin (PTX) is a potent marine toxin that causies serious damage to various tissues and organs. It has been reported to affect the transport of cations across the plasma membranes, which is commonly recognized as being the principal mechanism of its highly toxic action on mammals, including humans. However, although some marine toxins have been shown to cause toxic effects on the nervous system by interfering with the transmission of nerve impulses, the effect of PTX on neuronal cells has not yet been fully elucidated. Therefore, the toxic action of PTX on PC12 cells was examined as an in vitro model experiment to elucidate the neurotoxic properties of this toxin, and PTX was shown to reduce the viability of PC12 cells in a concentration-dependent manner. The cytotoxic action of PTX was not significantly altered by the presence of the antioxidant N-acetylcysteine and reduced-form glutathione in the cultures. Fluorescence staining of the cells and the electrophoretic analysis of genomic DNA showed that PTX failed to cause chromatin condensation and DNA fragmentation within the cells. On the other hand, the exposure to PTX caused positive staining of the cytoplasmic space of the cells with propidium iodide and the release of lactate dehydrogenase into the culture medium. Based on these observations, PTX is considered to cause cell death as a consequence of disrupting the plasma membranes, thus causing nonoxidative necrotic damage to PC12 cells. PMID:21913210

Sagara, Takefumi; Nishibori, Naoyoshi; Itoh, Mari; Morita, Kyoji; Her, Song

2011-09-13

297

An automatic 3D tracking system with a PC and a single TV camera.  

PubMed

We developed a novel system, for tracking a freely moving object (animal) in a limited 3D space, based on a closed loop TV and PC. Instead of using a pair of TV cameras to capture the 3D scene through the pair of its orthogonal projections, the system captures these projections by using a single TV camera. The direct view of the scene (e.g. its ground plan, i.e. projection onto the x-y plane) is captured together with its side projection, (i.e. projection onto the z-x plane) observed in a slanted mirror. The system uses a simple detection algorithm and hardware that were originally developed for 2D tracking of a single, contrast object on a stable and homogeneous background. All three coordinates of the tracked object are evaluated, displayed and stored in real-time, at 25 interlaced frames (samples) per second. The system was implemented on an IBM PC enhanced by an universal I/O board (Kaminsky, Yu, Krekule, I. Universal multifunctional IBM PC I/O board for clinical examinations and experimental research in neuroscience. Physiol Res 1994;43:193-199) and tested by tracking a LED marker, a small living fish in a water tank and a pair of LED markers which were activated one at the time in alternating TV frames thereby demonstrating the ability to simultaneously track two or more objects in 3D. PMID:10389666

Chrásková, J; Kaminsky, Y; Krekule, I

1999-05-01

298

Wf/pc Cycle 1 Calibration: UV GRISM Test  

NASA Astrophysics Data System (ADS)

This program obtains UV grism (G200L) exposures on each PC detector of the standard star A+81D266. These observations must be obtained immediately following a WF/PC decontamination to be useful. There observations will: 1) Validate the modified exposure times used in the SMS based UV flood proposal (Dec 1991). 2) Aid in the determination of the success of the flash decontamination relative to a high temp decon. 3) Assess the absence of contamination on the external WF/PC optical (pickoff mirror and plug).

MacKenty, John

1991-07-01

299

The Australian experience with the PC-EVN recorder  

NASA Astrophysics Data System (ADS)

We report on our experiences using the Metsähovi Radio Observatory's (MRO) VLBI Standard Interface (VSI, Whitney 2002) recorder in a number of astronomical applications. The PC-EVN device is a direct memory access (DMA) interface which allows 512 megabit per second (Mbps) or better recording to ``off the shelf'' PC components. We have used this setup to record at 640 Mbps for a pulsar coherent dispersion system and at 256 Mpbs for a global VLBI session. We have also demonstrated recording at 512 Mbps and will shortly form cross correlations between the CPSR-II and the PC-EVN systems. (astro-ph/0412685)

Dodson, R.; Tingay, S.; West, C.; Phillips, C.; Tzioumis, A. K.; Ritakari, J.; Briggs, F.

300

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

301

Stochastic simulation of pulverized coal (PC) processes  

SciTech Connect

An increasing population and electricity demand in the U.S. require capacity expansion of power systems. The National Energy Technology Laboratory (NETL), U.S. Department of Energy (DOE), has invested considerable efforts on research and development to improve the design and simulation of these power plants. Incorporation of novel process synthesis techniques and realistic simulation methodologies yield optimal flowsheet configurations and accurate estimation of their performance parameters. To provide a better estimation of such performance indicators, simulation models should predict the process behavior based on not only deterministic values of well-known input parameters but also uncertain variables associated with simulation assumptions. In this work, the stochastic simulation of a load-following pulverized coal (PC) power plant takes into account the variation of three input variables, namely, atmospheric air temperature, atmospheric air humidity, and generation load. These uncertain variables are characterized with probability density functions (pdfs) obtained from available atmospheric and electrical energy generation data. The stochastic simulation is carried out by obtaining a sample of values from the pdfs that generates a set of scenarios under which the model is run. An efficient sampling technique [Hammersley sequence sampling (HSS)] guarantees a set of scenarios uniformly distributed throughout the uncertain variable range. Then, each model run generates results on performance parameters as cycle efficiency, carbon emissions, sulfur emissions, and water consumption that are statistically analyzed after all runs are completed. Among these parameters, water consumption is of importance because an increasing demand has been observed mostly in arid regions of the country and, therefore, constrains the operability of the processes. This water consumption is significantly affected by atmospheric uncertainties. The original deterministic process model simulation was designed in Aspen Plus, and a CAPE-OPEN compliant stochastic simulation capability is employed to run the uncertainty analysis. Initially, the influences of atmospheric conditions and load change on the performance parameters are analyzed separately to understand their individual influences on the process, and then their simultaneous variation is analyzed to generate more realistic estimations of the process performance.

Salazar, J.; Diwekar, U.; Zitney, S.

2010-01-01

302

Working group 4 of International Standardization Organization -experience of developing the standards of space environment: status of 2010 and roadmap for the future  

NASA Astrophysics Data System (ADS)

Since the beginning of 90's space environment international standards have been developed within the scope of ISO WG4 activities. This has been the first attempt to develop interna-tional standards of physical phenomena of natural environment such as galactic cosmic rays (GCR), solar energetic particles (SEP), the Earth's magnetic field, the ionosphere, the plasma-sphere, etc. The main difficulty faced when developing the international standards is the lack of common methods for characterizing many natural phenomena. However, if methods have been successfully developed, such standards can play an outstanding role in the engineering requirements for spacecraft designs. This report is a survey of the current status of the inter-national standards under development within the scope of the WG4 activity plan and roadmap for the future.

Panasyuk, Mikhail; Tobiska, W. Kent

303

Pc 5 Spectral Density at ULTIMA stataions and its Radial Diffusion Coefficients for REE  

NASA Astrophysics Data System (ADS)

Pc 5 magnetic pulsations with frequencies between 1.67 and 6.67 mHz, are believed to contribute to the Relativistic Electron Enhancement (REE) in the outer radiation belt during magnetic storms. Ground-based observations suggested that high-speed solar wind and large-amplitude Pc 5 waves with a long duration during the storm recovery phase are closely associated with the production of relativistic electrons [Baker et al., 1998; Rostoker et al., 1998; Mathie and Mann, 2000; O’Brien et al., 2001, 2003]. On the other hand, many relativistic electron acceleration mechanisms have been proposed theoretically. They are separated roughly into two themes: in situ acceleration at L lower than 6.6 by wave particle interactions (as internal source acceleration mechanisms) [Liu et al., 1999; Summers et al., 1999; Summers and Ma, 2000] and acceleration by radial diffusion to transport and accelerate a source population of electrons from the outer to the inner magnetosphere (as external source acceleration mechanisms) [Elkington et al., 1999, 2003; Hudson et al., 2000; Kim et al., 2001]. One possible external source acceleration mechanism is the resonant interaction with ULF toroidal and poloidal waves. In order to verify which of the two mechanisms is more effective for the REE, we have to examine the time variation of electron phase space density. Electron phase space density is not directly measured, but we can estimate radial diffusion coefficients using observational electric and magnetic data. The goal of this paper is to get more reliable radial diffusion coefficient from ground-based observational magnetic field and to show reasonability of it for radial diffusion model. We use the global magnetometer data obtained from ULTIMA (Ultra Large Terrestrial International Magnetic Array, see http://www.serc.kyushu-u.ac.jp/ultima/ultima.html) stations, to precisely define the radial diffusion timescales. The ULTIMA includes McMAC, CARISAM, 210MM and MAGDAS/CPMN magnetometer arrays. The radial diffusion coefficient can be given from the magnetic field power spectral density as a function of L, frequency (f) and m-number (m) in the Pc 5 frequency range during the REE related magnetic storms [see Brautigam et al., 2005]. We can fit Pc 5 power spectral density (L, f, m) using the ULTIMA data. The m-number of global Pc 5 pulsation on the ground is found to be almost less than 5. This is consistent with m-number required in the radial diffusion theory by Elkington et al. [1999, 2003]. We will compare the observationally estimated diffusion coefficient with theoretical diffusion coefficient [e.g. Elkington et al., 2006], and discuss adequacy of our diffusion coefficient.

Fujimoto, A.; Tokunaga, T.; Abe, S.; Uozumi, T.; Yoshikawa, A.; Mann, I. R.; Chi, P. J.; Engebretson, M. J.; Yumoto, K.

2009-12-01

304

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.

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

2011-01-01

305

Gene repression by Polycomb group protein complexes: a distinct complex for every occasion?  

Microsoft Academic Search

Polycomb group (PcG) proteins play important roles in maintaining the repressed transcriptional state of genes. PcG proteins operate as part of Polycomb repressive complexes (PRCs). ‘Core’ PRCs have been purified that contain only a limited number of PcG proteins. In addition, many gene regulatory proteins have been identified to interact with PcG proteins. However, it remains subject to discussion whether

Arie P Otte; Ted HJ Kwaks

2003-01-01

306

PC BEEPOP, an Ecotoxicological Simulation Model for Honey Bee Populations.  

National Technical Information Service (NTIS)

PC BEEPOP is a computer model that simulates honey bee (Apis mellifera L.) colony population dynamics. The model consists of a feedback system of interdependent elements, including colony condition (e.g., initial size, reproductive potential of the queen ...

J. J. Bromenshenk J. Doskocil G. J. Olbu G. DeGrandi-Hoffman S. A. Roth

1991-01-01

307

Global wiring strategy for IC and PC routing  

SciTech Connect

A global (topological) router is presented which can be used for both custom IC routing and PC (gate array) routing. It is based on a graph theoretical model and effectively models both wire length and area figures of merit.

Wisniewski, J.A.; Hudson, J.A.

1983-01-01

308

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...

309

Collaboration using multiple PDAs connected to a PC  

Microsoft Academic Search

The Pebbles project is creating applications to connect multiple Personal Digital Assistants (PDAs) to a main com- puter such as a PC. We are using 3Com PalmPilots because they are starting to be ubiquitous. We created the \\

Brad A. Myers; Herb Stiell; Robert Gargiulo

1998-01-01

310

41 CFR 128-1.5002-8 - Property custodian (PC).  

Code of Federal Regulations, 2013 CFR

...50-Authorities and Responsibilities for Personal Property Management § 128-1.5002-8 Property custodian (PC). An individual responsible for the immediate physical custody of all personal property under his control and for...

2013-01-01

311

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...

312

FPGA and embedded PC based module for research and education  

NASA Astrophysics Data System (ADS)

This paper presents a versatile experimental and educational module, which can be used both for prototyping of embedded PC based electronic devices, and for teaching of computer engineering. The FPGA chip may be used to implement or to emulate wide range of hardware devices, while the embedded PC, able to run the Linux OS, provides an efficient environment for controlling this hardware using different techniques.

Zabolotny, Wojciech M.; Husejko, Michal; Zaworski, Wojciech

2005-02-01

313

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

314

The development of Bio-based Polymers for Notebook PC  

Microsoft Academic Search

The article discusses the life cycle of personal computer (PC) housings made from plant resin and analyzed their environmental burden by considering carbon dioxide (CO2) emissions and various inputs such as energy and resources during the life cycle. We compared the levels of CO2 emission from PC housings made from bio- and fossil-fuel-based polymers throughout their life cycles. There were

Koichi Kimura; Y. Horikoshi; T. Hashitani; K. Nihsii

2005-01-01

315

Flame retarding PC\\/ABS resins having superior thermomechanical properties  

Microsoft Academic Search

Triphenyl phosphate (TPP) is well known to be one of the most effective flame retardants for acrylonitrile-butadiene-styrene\\u000a copolymer (ABS) and its blending resins, such as polycarbonate (PC)\\/ABS, among various phosphorous-based compounds. However,\\u000a TPP can also play a role as a plasticizer, which decreases the mechanical properties of PC\\/ABS resins at high temperature.\\u000a Furthermore considerable amount of TPP has to be

Kwang Ho Sohn; Min Kwan Kim; So Min Lee; Byung Chul Ji; Kwang Soo Cho; Kyungmoon Jeon; Han Do Ghim

2011-01-01

316

A technique for preparing protein gradients on polymeric surfaces: effects on PC12 pheochromocytoma cells.  

PubMed

A technique for preparing micropatterns and gradients of proteins on polymeric substrates has been developed in this work. Peroxides were generated on the substrate surface by UV preirradiation and they initiated graft polymerization of acrylic acid (AA) onto the surface upon a second UV irradiation. Micropatterns and gradients of poly(acrylic acid) (PAA) were formed when the substrate was placed under or moved with respect to a photomask during UV preirradiation. Protein micropatterns and gradients were fabricated on the surface by covalently linking to the carboxyl groups on PAA chains. To test cell response to the protein gradient surfaces, PC12 pheochromocytoma cells were cultured on laminin-bound substrates in serum-free medium supplemented with nerve growth factor (NGF). It is found that both the attachment and neurite outgrowth behaviors of PC12 cells were dependent on the surface laminin density. However, the unreacted carboxyl groups on the polymer surface negatively affected PC12 cells. This weakened the positive influence from laminin. PMID:15522750

Li, Bin; Ma, Yuexia; Wang, Shu; Moran, Peter M

2005-05-01

317

Strategies, Programs and Projects 2008 of the Astrophysical Group "SPACE-Universidad Nacional Mayor De San Marcos, Peru" - Preparing for the IYA2009  

NASA Astrophysics Data System (ADS)

We present a review of our efforts to introduce astronomy as scientific career in Peru, showing how our astronomy outreach programs have been one of the most important keys to reach our national astronomical scientific goals, remarking the crucial role that the celebration of the IYA2009 must play, in order to promote PhD programmes in astronomy in developing countries. We show the importance of the creation of the Seminario Permanente de Astronomía y Ciencias Espaciales (SPACE) in the Universidad Nacional Mayor de San Marcos, as an academic scientific and cultural center in Peru, to support our 26 years-old "Astronomical Fridays” which are addressed to wide range of public, from schoolchildren to scientists. We also show how important was to rediscover our ancient astronomical cultural past of Incas in order to promote the construction of a Astronomical Center located near Cusco city over 4000 meters above sea level, which includes a tourist-educational observatory, a scientific optical observatory and a solar radio observatory.

Vera, Victor; Aguilar, M.; Huisacayna, J.

2008-05-01

318

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

319

Space Discovery.  

ERIC Educational Resources Information Center

|Describes one teacher's experience taking Space Discovery courses that were sponsored by the United States Space Foundation (USSF). These courses examine the history of space science, theory of orbits and rocketry, the effects of living in outer space on humans, and space weather. (DDR)|

Blackman, Joan

1998-01-01

320

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

321

The Use of Soft Detergents in P-C-436b and P-C-437 Cleaners.  

National Technical Information Service (NTIS)

Anticipating Federal Legislation banning the use of hard detergents, a feasibility study was made of the substitution of commercially-available, soft detergents in alkaline soak, hydrosteam, and high pressure steam cleaners of Federal Specifications P-C-4...

A. Mankowich

1964-01-01

322

Spatial and temporal variability of the dimethylsulfide to chlorophyll ratio in the surface ocean: an assessment based on phytoplankton group dominance determined from space  

NASA Astrophysics Data System (ADS)

Dimethylsulfoniopropionate (DMSP) is produced in surface seawater by phytoplankton. Phytoplankton culture experiments have shown that nanoeucaryotes (NANO) display much higher mean DMSP-to-Carbon or DMSP-to-Chlorophyll (Chl) ratios than Prochlorococcus (PRO), Synechococcus (SYN) or diatoms (DIAT). Moreover, the DMSP-lyase activity of algae which cleaves DMSP into dimethylsulfide (DMS) is even more group specific than DMSP itself. Ship-based observations have shown at limited spatial scales, that sea surface DMS-to-Chl ratios (DMS:Chl) are dependent on the composition of phytoplankton groups. Here we use satellite remote sensing of Chl (from SeaWiFS) and of Phytoplankton Group Dominance (PGD from PHYSAT) with ship-based sea surface DMS concentrations (8 cruises in total) to assess this dependence on an unprecedented spatial scale. PHYSAT provides PGD (either NANO, PRO, SYN, DIAT, Phaeocystis (PHAEO) or coccolithophores (COC)) in each satellite pixel (1/4° horizontal resolution). While there are identification errors in the PHYSAT method, it is important to note that these errors are lowest for NANO PGD which we typify by high DMSP:Chl. In summer, in the Indian sector of the Southern Ocean, we find that mean DMS:Chl associated with NANO + PHAEO and PRO + SYN + DIAT are 13.6±8.4 mmol g-1 (n=34) and 7.3±4.8 mmol g-1 (n=24), respectively. That is a statistically significant difference (P<0.001) that is consistent with NANO and PHAEO being relatively high DMSP producers. However, in the western North Atlantic between 40° N and 60° N, we find no significant difference between the same PGD. This is most likely because coccolithophores account for the non-dominant part of the summer phytoplankton assemblages. Meridional distributions at 22° W in the Atlantic, and 95° W and 110° W in the Pacific, both show a marked drop in DMS:Chl near the equator, down to few mmol g-1, yet the basins exhibit different PGD (NANO in the Atlantic, PRO and SYN in the Pacific). In tropical and subtropical Atlantic and Pacific waters away from the equatorial and coastal upwelling, mean DMS:Chl associated with high and low DMSP producers are statistically significantly different, but the difference is opposite of that expected from culture experiments. Hence, in a majority of cases PGD is not of primary importance in controlling DMS:Chl variations. We therefore conclude that water-leaving radiance spectra obtained simultaneously from ocean color sensor measurements of Chl concentrations and dominant phytoplankton groups can not be used to predict global fields of DMS.

Masotti, I.; Belviso, S.; Alvain, S.; Johnson, J. E.; Bates, T. S.; Tortell, P. D.; Kasamatsu, N.; Mongin, M.; Marandino, C. A.; Saltzman, E. S.; Moulin, C.

2010-10-01

323

Pc1Pc2 waves and energetic particle precipitation during and after magnetic storms: Superposed epoch analysis and case studies  

Microsoft Academic Search

Magnetic pulsations in the Pc1-Pc2 frequency range (0.1-5 Hz) are often observed on the ground and in the Earth's magnetosphere during the aftermath of geomagnetic storms. Numerous studies have suggested that they may play a role in reducing the fluxes of energetic ions in the ring current; more recent studies suggest they may interact parasitically with radiation belt electrons as

M. J. Engebretson; M. R. Lessard; J. Bortnik; J. C. Green; R. B. Horne; D. L. Detrick; A. T. Weatherwax; J. Manninen; N. J. Petit; J. L. Posch; M. C. Rose

2008-01-01

324

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

325

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

PubMed

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, ?-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

Nie, Ying; Ferrini, Monica G; Liu, Yanjun; Anghel, Adrian; Espinosa, Enma V Paez; Stuart, Ronald C; Lutfy, Kabirullah; Nillni, Eduardo A; Friedman, Theodore C

2013-07-26

326

PC Tutor. Bericht uber ein PC-gestutzes Tutorensystem = PC Tutor. Report on a Tutoring System with Personal Computer. ZIFF Papiere 75.  

ERIC Educational Resources Information Center

|A project was conducted to increase as well as to professionalize communication between tutors and learners in a West German university's distance education program by the use of personal computers. Two tutors worked on the systematic development of a PC-based correcting system. The goal, apart from developing general language skills in English,…

Fritsch, Helmut

327

Architectural and functional diversity of polycomb group response elements in Drosophila.  

PubMed

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

2013-08-09

328

METHANE de-NOX FOR UTILITY PC BOILERS  

SciTech Connect

The project seeks to develop and validate a new pulverized coal combustion system to reduce utility PC boiler NOx emissions to 0.15 lb per million Btu or less without post-combustion flue gas cleaning. Work during previous reporting periods completed the design, installation, shakedown and initial PRB coal testing of a 3-million Btu/h pilot system at BBP's Pilot-Scale Combustion Facility (PSCF) in Worcester, MA. Based on these results, modifications to the gas-fired preheat combustor and PC burner were defined, along with a modified testing plan and schedule. A revised subcontract was executed with BBP to reflect changes in the pilot testing program. Modeling activities were continued to develop and verify revised design approaches for both the Preheat gas combustor and PC burner. Reactivation of the pilot test system was then begun with BBP personnel. During the previous reporting period, reactivation of the pilot test system was completed with the modified Preheat gas combustor. Following shakedown of the modified gas combustor alone, a series of successful tests of the new combustor with PRB coal using the original PC burner were completed. NOx at the furnace exit was reduced significantly with the modified gas combustor, to as low as 150 ppm with only 36 ppm CO (both corrected to 3% O2). Concurrent with testing, GTI and BBP collaborated on development of two modified designs for the PC burner optimized to fire preheated char and pyrolysis products from the Preheat gas combustor. During the current reporting period, one of the two modified PC burner designs was fabricated and installed in the pilot test facility. Testing of the modified pilot system (modified gas combustor and modified PC burner) during the quarter included 38 tests with PRB coal. NOx reduction was significantly improved to levels as low as 60-100 ppmv with CO in the range of 35-112 ppmv without any furnace air staging.

Joseph Rabovitser; Bruce Bryan; Serguei Nester; Stan Wohadlo

2002-01-31

329

Effects of pyridine analogs of curcumin on growth, apoptosis and NF-?B activity in prostate cancer PC-3 cells.  

PubMed

Twelve pyridine analogs of curcumin were studied for their effects on growth and apoptosis in human prostate cancer PC-3 cells. The ability of these compounds to inhibit the transcriptional activity of nuclear factor-kappa B (NF-?B) and the level of phosphorylated extracellular signal-regulated kinases (phospho-ERK1/2) in PC-3 cells was also determined. Treatment of PC-3 cells with the pyridine analogs of curcumin resulted in concentration-dependent growth inhibition and apoptosis stimulation. Only pyridine analogs of curcumin with a tetrahydrothiopyrane-4-one linker (FN compounds) exhibited a strong inhibitory effect on growth and a strong stimulatory effect on apoptosis at low concentrations (? 1 ?M). Mechanistic studies showed that NF-?B transcriptional activity in PC-3 cells was strongly inhibited by treatment with group FN compounds. Treatment of PC-3 cells with 1 ?M FN1 resulted in a decrease of activated ERK1/2. Results from the present study indicate that FN compounds warrant further in vivo studies using suitable animal models of prostate cancer. PMID:23564771

Wei, Xingchuan; Zhou, Daiying; Wang, Huaqian; Ding, Ning; Cui, Xiao-Xing; Wang, Hong; Verano, Michael; Zhang, Kun; Conney, Allan H; Zheng, Xi; DU, Zhi-Yun

2013-04-01

330

Axes in Outer Space  

Microsoft Academic Search

We develop a notion of axis in the Culler--Vogtmann outer space X_r of a finite rank free group F_r, with respect to the action of a nongeometric, fully irreducible outer automorphism phi. Unlike the situation of a loxodromic isometry acting on hyperbolic space, or a pseudo-Anosov mapping class acting on Teichmuller space, X_r has no natural metric, and phi seems

Michael Handel; Lee Mosher

2006-01-01

331

Pc1-Pc2 waves and energetic particle precipitation during and after magnetic storms: Superposed epoch analysis and case studies  

NASA Astrophysics Data System (ADS)

Magnetic pulsations in the Pc1-Pc2 frequency range (0.1-5 Hz) are often observed on the ground and in the Earth's magnetosphere during the aftermath of geomagnetic storms. Numerous studies have suggested that they may play a role in reducing the fluxes of energetic ions in the ring current; more recent studies suggest they may interact parasitically with radiation belt electrons as well. We report here on observations during 2005 from search coil magnetometers and riometers installed at three Antarctic stations, Halley (-61.84° magnetic latitude, MLAT), South Pole (-74.18° MLAT), and McMurdo (-79.96° MLAT), and from energetic ion detectors on the NOAA Polar-orbiting Operational Environment Satellites (POES). A superposed epoch analysis based on 13 magnetic storms between April and September 2005 as well as case studies confirm several earlier studies that show that narrowband Pc1-Pc2 waves are rarely if ever observed on the ground during the main and early recovery phases of magnetic storms. However, intense broadband Pi1-Pi2 ULF noise, accompanied by strong riometer absorption signatures, does occur during these times. As storm recovery progresses, the occurrence of Pc1-Pc2 waves increases, at first in the daytime and especially afternoon sectors but at essentially all local times later in the recovery phase (typically by days 3 or 4). During the early storm recovery phase the propagation of Pc1-Pc2 waves through the ionospheric waveguide to higher latitudes was more severely attenuated. These observations are consistent with suggestions that Pc1-Pc2 waves occurring during the early recovery phase of magnetic storms are generated in association with plasmaspheric plumes in the noon-to-dusk sector, and these observations provide additional evidence that the propagation of waves to ground stations is inhibited during the early phases of such storms. Analysis of 30- to 250-keV proton data from four POES satellites during the 24-27 August and 18-19 July 2005 storm intervals showed that the location of the inner edge of the ring current matched well with the plasmapause model of O'Brien and Moldwin (2003). However, the POES data showed no evidence of the consequences of electromagnetic ion cyclotron waves (localized proton precipitation) during main and early recovery phase. During later stages of the recovery phase, when such precipitation was observed, it was coincident with intense wave events at Halley, and it occurred at L shells near or up to 1 RE outside the modeled plasmapause but well equatorward of the isotropy boundary.

Engebretson, M. J.; Lessard, M. R.; Bortnik, J.; Green, J. C.; Horne, R. B.; Detrick, D. L.; Weatherwax, A. T.; Manninen, J.; Petit, N. J.; Posch, J. L.; Rose, M. C.

2008-01-01

332

Austrian Space Agency  

NSDL National Science Digital Library

"The Austrian Space Agency, ASA, established by the Federal authorities in Vienna in 1972, serves as a focal point for the co-ordination of space activities in Austria and is the Austrian link to international space activities." The website offers summaries of the organization's past and present research activities with the ESA Space Science Programme and the International Mars Exploration Working Group (IMEWG). Users can find inspiring biographies of nine Austrian space pioneers as well as information on the latest news and events. While the English version of the organization's work in nanotechnology and aeronautics is not yet available, the Space link provides materials on many educational opportunities including details of the Alpbach Summer School and information on courses in space law.

333

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

PubMed

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 Ubx(OFF)and Ubx(ON)cells 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

2006-08-01

334

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

335

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

336

Large-scale parallel configuration interaction. II. Two- and four-component double-group general active space implementation with application to BiH  

NASA Astrophysics Data System (ADS)

We present a parallel implementation of a large-scale relativistic double-group configuration interaction (CI) program. It is applicable with a large variety of two- and four-component Hamiltonians. The parallel algorithm is based on a distributed data model in combination with a static load balancing scheme. The excellent scalability of our parallelization scheme is demonstrated in large-scale four-component multireference CI (MRCI) benchmark tests on two of the most common computer architectures, and we also discuss hardware-dependent aspects with respect to possible speedup limitations. With the new code we have been able to calculate accurate spectroscopic properties for the ground state and the first excited state of the BiH molecule using extensive basis sets. We focused, in particular, on an accurate description of the splitting of these two states which is caused by spin-orbit coupling. Our largest parallel MRCI calculation thereby comprised an expansion length of 2.7×109 Slater determinants.

Knecht, Stefan; Jensen, Hans Jørgen Aa.; Fleig, Timo

2010-01-01

337

Large-scale parallel configuration interaction. II. Two- and four-component double-group general active space implementation with application to BiH.  

PubMed

We present a parallel implementation of a large-scale relativistic double-group configuration interaction (CI) program. It is applicable with a large variety of two- and four-component Hamiltonians. The parallel algorithm is based on a distributed data model in combination with a static load balancing scheme. The excellent scalability of our parallelization scheme is demonstrated in large-scale four-component multireference CI (MRCI) benchmark tests on two of the most common computer architectures, and we also discuss hardware-dependent aspects with respect to possible speedup limitations. With the new code we have been able to calculate accurate spectroscopic properties for the ground state and the first excited state of the BiH molecule using extensive basis sets. We focused, in particular, on an accurate description of the splitting of these two states which is caused by spin-orbit coupling. Our largest parallel MRCI calculation thereby comprised an expansion length of 2.7x10(9) Slater determinants. PMID:20078150

Knecht, Stefan; Jensen, Hans Jørgen Aa; Fleig, Timo

2010-01-01

338

PC-based PCM telemetry data reduction system software  

SciTech Connect

The Solar Energy Research Institute's (SERI) Wind Research Program is using pulse code modulation (PCM) telemetry systems to study horizontal-axis wind turbines. SERI has developed a low-cost PC-based PCM data-acquisition system to facilitate quick PCM data analysis in the field. The SERI PC-PCM system consists of AT-compatible hardware boards for decoding and combining PCM data streams and DOS software for control and management of data acquisition. Up to four boards can be installed in a single PC, providing the capability to combine data from four PCM streams direct to disk or memory. This paper describes the SERI Quick-Look Data Management Program, which is a comprehensive software package used to organize, acquire, process, and display information from PCM data streams. The software was designed for use in conjunction with SERI's PC-PCM hardware described in a related paper. Features of the Quick-Look program are highlighted, including those which make it useful in an experiment test environment to quickly examine and verify incoming data. Also discussed are problems and techniques associated with PC-based PCM data acquisition, processing, and real-time display. 7 refs., 4 figs., 2 tabs.

Simms, D.A.

1990-02-01

339

Pc 3-4 Pulsations Near the Cusp: Observations using Search Coil Magnetometers and HF Radars on Svalbard  

NASA Astrophysics Data System (ADS)

Pc 3-4 pulsations (f ~10-100 mHz) originating in the ion foreshock upstream of Earth's bow shock due to the interaction between reflected ions and the solar wind frequently are observed in dayside ground magnetometer records at high latitudes. Many early studies noted increased Pc 3-4 wave power in the vicinity of the dayside cusp and inferred entry via the cusp, but later studies have revealed a more complex picture. In this study, we examined power near local noon at Pc 3-4 frequencies observed by search coil magnetometers at three closely-spaced stations on Svalbard (Ny Alesund, Longyearbyen, and Hornsund). Nineteen days with clear band-limited Pc 3-4 wave power near local noon, and thirteen days with only broadband wave power, were selected for which clear cusp signatures were available in data from the Finland SuperDARN radar, which was used to accurately determine the cusp latitude. 3-s resolution fixed- beam mode data from a radar beam viewing over Svalbard also made it possible to determine Pc 3-4 periodicity in regions of the cusp and auroral zone ionosphere that returned sufficient signal. Band-limited (Pc 3-4) and broadband ULF signals in near-noon magnetometer data showed a similar latitude distribution: wave power peaked about 4-5 degrees south of the cusp. Radar backscatter from the cusp showed no evidence of Pc 3-4 modulation in this region during any of these intervals, whereas two intervals of data at lower latitudes did show modulation at Pc 3-4 frequencies. These observations are consistent not with entry via the cusp proper but along field lines equatorward of the cusp which map to the low-latitude boundary layer or outer magnetosphere. Because this location is similar to that observed for the maximum power of traveling convection vortex events / magnetic impulse events (TCVs/MIEs), we suggest that similar physics may play a role in transmitting perturbations from the upstream solar wind into the dayside magnetosphere in both cases.

Engebretson, M. J.; Lu, F.; Posch, J.; Lessard, M. R.; Kim, H.; Wright, D.; Yeoman, T.; Johnson, J.

2008-12-01

340

4D phase contrast MRI at 3 T: effect of standard and blood-pool contrast agents on SNR, PC-MRA, and blood flow visualization.  

PubMed

Time-resolved phase contrast (PC) MRI with velocity encoding in three directions (flow-sensitive four-dimensional MRI) can be employed to assess three-dimensional blood flow in the entire aortic lumen within a single measurement. These data can be used not only for the visualization of blood flow but also to derive additional information on vascular geometry with three-dimensional PC MR angiography (MRA). As PC-MRA is sensitive to available signal-to-noise ratio, standard and novel blood pool contrast agents may help to enhance PC-MRA image quality. In a group of 30 healthy volunteers, the influence of different contrast agents on vascular signal-to-noise ratio, PC-MRA quality, and subsequent three-dimensional stream-line visualization in the thoracic aorta was determined. Flow-sensitive four-dimensional MRI data acquired with contrast agent provided significantly improved signal-to-noise ratio in magnitude data and noise reduction in velocity data compared to measurements without contrast media. The agreement of three-dimensional PC-MRA with reference standard contrast-enhanced MRA was good for both contrast agents, with improved PC-MRA performance for blood pool contrast agent, particularly for the smaller supra-aortic branches. For three-dimensional flow visualization, a trend toward improved results for the data with contrast agent was observed. PMID:20024953

Bock, Jelena; Frydrychowicz, Alex; Stalder, Aurélien F; Bley, Thorsten A; Burkhardt, Hans; Hennig, Jürgen; Markl, Michael

2010-02-01

341

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

342

Potential Cysteine Redox Regulation of the Polycomb Group.  

National Technical Information Service (NTIS)

The Polycomb Group (PcG) of gene silencers are chromatin associated multi-protein complexes that maintain cell identity by regulating the expression of genomic programming genes. In stem cells, PcG complexes occupy hundreds of genomic sites repressing gen...

C. A. Kim

2005-01-01

343

Potential Cysteine Redox Regulation of the Polycomb Group.  

National Technical Information Service (NTIS)

The Polycomb Group (PcG) of gene silencers are chromatin associated multi-protein complexes that maintain cell identity by regulating the expression of genomic programming genes. In stem cells, PcG complexes occupy hundreds of genomic sites repressing gen...

C. A. Kim

2010-01-01

344

An unusal case of facile non-degenerate P-C bond making and breaking.  

PubMed

Oxidation of Li/X phosphinidenoid complex 2, obtained via selective deprotonation from the P-H precursor 1, with [Ph(3)C]BF(4) led to the formation of two P-F substituted diorganophosphane complexes 6,7; the latter tautomer 7 formed via H-shift from 6. In contrast, oxidation of 2 with [(p-Tol)(3)C]BF(4) led to three major and one minor intermediates at low temperature, which we tentatively assign to two pairs of P-C atropisomers 10?a,a' and 10?c,c' and which differ by the relative orientations of their CH(SiMe(3))(2) and W(CO)(5) groups. Conversion of all isomers led finally to complex 11 having a ligand with a long P-C bond to the central trityl* carbon atom, firmly established by single-crystal X-ray analysis. DFT calculations at the B3LYP/def2-TZVPP//BP86/def2-TZVP level of theory on real molecular entities revealed the structures of the in situ formed combined singlet diradicals (4+5 and 5+9) and the nature of intermediates on the way to the final product, complex 11. Remarkable is that all isomers of 11 possess relative energies in the narrow energy regime of about 20?kcal ?mol(-1). A preliminary study revealed that complex 11 undergoes selective P-C bond cleavage at 75?°C in toluene solution. PMID:22488865

Nesterov, Vitaly; Özbolat-Schön, Aysel; Schnakenburg, Gregor; Shi, Lili; Cangönül, Asli; van Gastel, Maurice; Neese, Frank; Streubel, Rainer

2012-04-05

345

In vitro effects of fetal rat cerebrospinal fluid on viability and neuronal differentiation of PC12 cells  

PubMed Central

Background Fetal cerebrospinal fluid (CSF) contains many neurotrophic and growth factors and has been shown to be capable of supporting viability, proliferation and differentiation of primary cortical progenitor cells. Rat pheochromocytoma PC12 cells have been widely used as an in vitro model of neuronal differentiation since they differentiate into sympathetic neuron-like cells in response to growth factors. This study aimed to establish whether PC12 cells were responsive to fetal CSF and therefore whether they might be used to investigate CSF physiology in a stable cell line lacking the time-specific response patterns of primary cells previously described. Methods In vitro assays of viability, proliferation and differentiation were carried out after incubation of PC12 cells in media with and without addition of fetal rat CSF. An MTT tetrazolium assay was used to assess cell viability and/or cell proliferation. Expression of neural differentiation markers (MAP-2 and ?-III tubulin) was determined by immunocytochemistry. Formation and growth of neurites was measured by image analysis. Results PC12 cells differentiate into neuronal cell types when exposed to bFGF. Viability and cell proliferation of PC12 cells cultured in CSF-supplemented medium from E18 rat fetuses were significantly elevated relative to the control group. Neuronal-like outgrowths from cells appeared following the application of bFGF or CSF from E17 and E19 fetuses but not E18 or E20 CSF. Beta-III tubulin was expressed in PC12 cells cultured in any media except that supplemented with E18 CSF. MAP-2 expression was found in control cultures and in those with E17 and E19 CSF. MAP2 was located in neurites except in E17 CSF when the whole cell was positive. Conclusions Fetal rat CSF supports viability and stimulates proliferation and neurogenic differentiation of PC12 cells in an age-dependent way, suggesting that CSF composition changes with age. This feature may be important in vivo for the promotion of normal brain development. There were significant differences in the effects on PC12 cells compared to primary cortical cells. This suggests there is an interaction in vivo between developmental stage of cells and the composition of CSF. The data presented here support an important, perhaps driving role for CSF composition, specifically neurotrophic factors, in neuronal survival, proliferation and differentiation. The effects of CSF on PC12 cells can thus be used to further investigate the role of CSF in driving development without the confounding issues of using primary cells.

2012-01-01

346

Space Day  

NSDL National Science Digital Library

Space Day '98, to be held on May 21, 1998, celebrates and honors the people who have made space exploration possible. The highlight of the Space Day homepage, maintained by Lockheed Martin Corporation, will be a live interactive webcast all day on May 21. Features of the webcast include experts in the fields of space discussing issues ranging from global collaboration to mysteries that remain. In addition to the webcast, the Space Day '98 home page provides resources for teachers and the curious alike. Mission: Fun allows visitors to test their space knowledge through interactive Shockwave games and quizzes while Teachers' Space provides educators with downloadable lesson plans (Adobe Acrobat [.pdf] format).

347

METHANE de-NOX FOR UTILITY PC BOILERS  

SciTech Connect

During the current quarter, pilot scale testing was continued with the modified combustor and modified channel burner using the new PRB coal delivered in late December. Testing included benchmark testing to determine whether the system performance was comparable to that with the previous batch of PRB coal, baseline testing to characterize performance of the PC Burner without coal preheating, and parametric testing to evaluate the effect of various preheat combustor and PC burner operating variables, including reduced gas usage in the preheat combustor. A second version of the PC burner in which the secondary air channels were closed and replaced with six air nozzles was then tested with PRB coal. Plans were developed with RPI for the next phase of testing at the 100 million Btu/h scale using RPI's Coal Burner Test Facility (CBTF). A cost estimate for preparation of the CBTF and preheat burner system design, installation and testing was then prepared by RPI.

Joseph Rabovitser; Bruce Bryan; Serguei Nester; Stan Wohadlo

2003-04-01

348

METHANE de-NOX FOR UTILITY PC BOILERS  

SciTech Connect

The project seeks to develop and validate a new pulverized coal combustion system to reduce utility PC boiler NOx emissions to 0.15 lb/million Btu or less without post-combustion flue gas cleaning. Work during previous reporting periods completed the design, installation, shakedown and initial PRB coal testing of a 3-million Btu/h pilot system at BBP's Pilot-Scale Combustion Facility (PSCF) in Worcester, MA. Based on these results, modifications to the gas-fired preheat combustor and PC burner were defined, along with a modified testing plan and schedule. During the current reporting period, BBP's subcontract was modified to reflect changes in the pilot testing program, and the modifications to the gas-fired preheat combustor were completed. The Computational Fluid Dynamics (CFD) modeling approach was defined for the combined PC burner and 3-million Btu/h pilot system. Modeling of the modified gas-fired preheat combustor was also started.

Joseph Rabovitser; Bruce Bryan; Serguei Nester; Stan Wohadlo

2002-04-29

349

Demonstration of a PC 25 Fuel Cell in Russia  

SciTech Connect

This project involved the installation of a 200kW PC25C{trademark} phosphoric-acid fuel cell power plant at Orgenergogaz, a Gazprom industrial site in Russia. In April 1997, a PC25C{trademark} was sold by ONSI Corporation to Orgenergogaz, a subsidiary of the Russian company ''Gazprom''. Due to instabilities in the Russian financial markets, at that time, the unit was never installed and started by Orgenergogaz. In October of 2001 International Fuel Cells (IFC), now known as UTC Fuel Cells (UTCFC), received a financial assistance award from the United States Department of Energy (DOE) entitled ''Demonstration of PC 25 Fuel Cell in Russia''. Three major tasks were part of this award: the inspection of the proposed site and system, start-up assistance, and installation and operation of the powerplant.

John C. Trocciola; Thomas N. Pompa; Linda S. Boyd

2004-09-01

350

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

351

A data acquisition system for spectroscopy using an IBM PC  

NASA Astrophysics Data System (ADS)

A real-time data acquisition computer system has been developed using an IBM PC/XT or PC/AT personal computer. Although the program was specifically written for Raman spectroscopy, it includes many subroutines which are generally useful for laboratory work. The PC coordinates all activities of the system, including photon counting, adjustment of optics within the spectrometer, display of spectra in real time, and analysis of data during acquisition. All of the hardware components are standard and commercially available. The program is written in FORTRAN-77 and assembly language, and contains independent subroutine packages which may be used to make modifications for individual experiments. These routines provide instructive examples on sending TTL signals through the parallel port, clock-driven interrupts, graphics operations, and RS-232 interfacing.

Lowe, Mary; Blumenroeder, Stephan; Kutt, Peter H.

1988-08-01

352

Real-time digital image stabilization algorithm on PC  

NASA Astrophysics Data System (ADS)

This paper presents a real-time digital image stabilization algorithm on PC to stabilize a sequence of images. The proposed algorithm can be divided into 3 steps. First step is to acquire an appropriate bit plane. It is easier and faster to compute with bit plane than original image. Second, through histogram processing, we can match cursorily. If there are error matches, we can use a block matching algorithm to match again to acquire exact result. Then the local motion vector can be obtained from it. If we apply inline MMX assemble language hybrid programming, we can make it faster of PC. Last, we eliminate the field motion vector produced in irregular conditions. Through this step, we can void local motion vectors affected by undesirable condition such as moving objects. The characteristic of this algorithm is fast and effective. By it, real-time digital image stabilization can be realized on PC.

Sun, Yi; Zhao, Yuejin; Zhou, Yubin; Liu, Mingqi; Lu, Hai; Yu, Feng

2002-09-01

353

Space Stuff  

NSDL National Science Digital Library

Students are introduced to general space science with information about astronauts, space probes, space travel, the Hubble Space Telescope, space suits, and the Columbia Shuttle accident. Biographies of important scientists and astronauts are included, and vocabulary crossword puzzles, maps, logic riddles, and coloring pages extend learning. Each page offers links to a glossary of important terms. A link to content for more advanced students is included.

354

SpaceTech—Postgraduate space education  

NASA Astrophysics Data System (ADS)

SpaceTech is a postgraduate program geared primarily for mid-career space professionals seeking to gain or improve their expertise in space systems engineering and in business engineering. SpaceTech provides a lifelong impact on its participants by broadening their capabilities, encouraging systematic "end-to-end" thinking and preparing them for any technical or business-related engineering challenges they may encounter. This flexible 1-year program offers high competency gain and increased business skills. It is held in attractive locations in a flexible, multi-cultural environment. SpaceTech is a highly effective master's program certified by the esteemed Technical University of Delft (TUD), Netherlands. SpaceTech provides expert instructors who place no barriers between themselves and participants. The program combines innovative and flexible new approaches with time-tested methods to give participants the skills required for future missions and new business, while allowing participants to meet their work commitments at the same time as they study for their master's degree. The SpaceTech program is conducted in separate sessions, generally each of 2-week duration, separated by periods of some 6-8 weeks, during which time participants may return to their normal jobs. It also includes introductory online course material that the participants can study at their leisure. The first session is held at the TUD, with subsequent sessions held at strategic space agency locations. By participating at two or more of these sessions, attendees can earn certificates of satisfactory completion from TU Delft. By participating in all of the sessions, as well as taking part in the companion Central Case Project (CCP), participants earn an accredited and highly respected master's degree in Space Systems Engineering from the TUD. Seven distinct SpaceTech modules are provided during these sessions: Space Mission Analysis and Design, Systems Engineering, Business Engineering, Interpersonal Skills, Telecommunications, Earth Observation and Navigation. A group CCP, a major asset of this unique program, is a focused project, aimed at the formation of a credible virtual commercial space-related business. Participants exercise space systems engineering fundamentals as well as marketing and business engineering tools, with the goal of creating a financially viable business opportunity. They then present the result, in the form of an unsolicited proposal to potential investors, as well as a varied group of engineers, managers and executives from the space community. During the CCP, participants learn the ties between mission and system design and the potential return to investors. They develop an instinct for the technical concepts and which of the parameters to adjust to make their newly conceived business more effective and profitable.

de Bruijn, Ferdi J.; Ashford, Edward W.; Larson, Wiley J.

2008-07-01

355

Magnetic subperiodic groups.  

PubMed

The magnetic subperiodic groups, the 31 magnetic frieze-group types, the 394 magnetic rod-group types and the 528 magnetic layer-group types, are derived and given symbols based on the symbols for the nonmagnetic subperiodic groups in Volume E of International Tables for Crystallography. The symbols are constructed in analogy to the Opechowski-Guccione symbols for magnetic space groups. Tables are given that list one group from each type. Each group is specified not only by its symbol but also by explicitly listing the coset representatives of the coset decomposition of the group with respect to its translational subgroup. PMID:10927306

Litvin

1999-09-01

356

Esrange Space Center, a Gate to Space  

NASA Astrophysics Data System (ADS)

Swedish Space Corporation (SSC) is operating the Esrange Space Center in northern Sweden. Space operations have been performed for more than 40 years. We have a unique combination of maintaining balloon and rocket launch operations, and building payloads, providing space vehicles and service systems. Sub-orbital rocket flights with land recovery and short to long duration balloon flights up to weeks are offered. The geographical location, land recovery area and the long term experience makes Swedish Space Corporation and Esrange to an ideal gate for space activities. Stratospheric balloons are primarily used in supporting atmospheric research, validation of satellites and testing of space systems. Balloon operations have been carried out at Esrange since 1974. A large number of balloon flights are yearly launched in cooperation with CNES, France. Since 2005 NASA/CSBF and Esrange provide long duration balloon flights to North America. Flight durations up to 5 days with giant balloons (1.2 Million cubic metres) carrying heavy payload (up to 2500kg) with astronomical instruments has been performed. Balloons are also used as a crane for lifting space vehicles or parachute systems to be dropped and tested from high altitude. Many scientific groups both in US, Europe and Japan have indicated a great need of long duration balloon flights. Esrange will perform a technical polar circum balloon flight during the summer 2008 testing balloon systems and flight technique. We are also working on a permission giving us the opportunity on a circular stratospheric balloon flight around the North Pole.

Widell, Ola

357

METHANE DE-NOX FOR UTILITY PC BOILERS  

SciTech Connect

The project seeks to develop and validate a new pulverized coal combustion system to reduce utility PC boiler NO{sub x} emissions to 0.15 lb/million Btu or less without post-combustion flue gas cleaning. Work during the quarter included completion of the equipment fabrication and installation efforts for the 3-million Btu/h pilot system at BBP's Pilot-Scale Combustion Facility (PSCF) in Worcester, MA. Selection and procurement of the first two test coals and preliminary selection of the final two test coals were completed. Shakedown and commissioning activities were finished and PC Preheat pilot scale tests commenced with PRB coal.

Joseph Rabovitser; Bruce Bryan; Serguei Nester; Stan Wohadlo

2002-01-31

358

Effect of morphine on PC12 cells with molecular radar  

NASA Astrophysics Data System (ADS)

Molecular Radar (MR) is a new method to detect biological processes in living cells at the level of molecular, it is also the newest means to get intracellular information. In this paper we study the effect of morphine on PC12 cells using MR. The results show that the effect of morphine on PC12 cells is time- and concentration-dependent. Morphine treating for short time induces the increase and fluctuation of intracellular (CA2+), while morphine treating for long time induces chromatin condensation, loss of mitochondria membrane potential apoptosis.

Shi, Chen; Yu, Xiaoli; Lu, Jiuyi; Zhang, Chun-Yang; Jin, Lei; Ma, Hui; Zhang, Dacheng; Chen, Dieyan

2000-10-01

359

METHANE de-NOX for Utility PC Boilers  

SciTech Connect

Large-scale combustion tests with caking bituminous coal has stopped. This stoppage has come about due to limitations in current funding available to continue large scale research and development activities at Riley's Commercial Burner Test Facility (CBTF) of the PC Preheat technology. The CBTF was secured and decommissioned in the previous quarter; work this quarter has focused on disposition of PC Preheat experimental equipment at the CBTF as well as methods for disposal of about 100 tons of residual PRB test coal in storage. GTI was granted a no-cost time extension through September 2005; a final report is due in December 2005.

Bruce Bryan; Joseph Rabovitser; Serguei Nester; Stan Wohadlo

2005-06-30

360

Run-08 pC polarization analysis - October 16, 2008  

SciTech Connect

In this note we will discuss the analysis of RHIC run 08 pC data that were collected during February 14 - March 10, 2008. An analysis method that is similar to Run 05 and Run 06 was adopted for Run 08 analysis (except few minor changes, which are described below). A detailed analysis note and a NIM article that describe the pC analysis procedure (for run 05 and run 06) can be found elsewhere. In brief, the analysis consists of calibrating the detectors, determining energy corrections ('dead layers'), determining good runs and extracting the polarization from data.

Dharmawardane,V.; Bazilevsky,A.; Bunce, G.; Gill, R.; Huang, H.; Makdisi, Y.; Nakagawa, I.; Morozov, B.; Okada, H.; Sivertz, M.; Zelenski, A.; Alekseev, I.; Svirida, D.

2009-03-01

361

COBOL on a PC: a new perspective on a language and its performance  

Microsoft Academic Search

A comparison of Cobol performance on the PC AT Enhanced versus an IBM 370 mainframe suggests that high-quality PC compiler implementations—combined with the new language features of the Cobol 85 Standard—are improving the PC environment for Cobol to the point where serious applications can now be developed and debugged on the PC, either to be run on the PC itself,

Paul J. Jalics

1987-01-01

362

Relationship Between Purity of CuPc and Properties of Organic Thin Photovoltaic Cells  

Microsoft Academic Search

Properties of organic thin photovoltaic cells using copper phthalocyanine (CuPc) with different purities are studied. When we change purity of CuPc, only open-circuit voltage (VOC) increases as CuPc material purity increases while short-circuit current show a same value. Decrease in VOC of cell using low-purity CuPc is maybe caused by impurities that are taken in CuPc layer. We show the

Kohei Kato; Tatsuo Mori

2007-01-01

363

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

364

Number of free hydroxyl groups on bile Acid phospholipids determines the fluidity and hydration of model membranes.  

PubMed

Interactions of synthetic phospholipids with model membranes determines the drug release capabilities of phospholipid vesicles at diseased sites. We performed 1,6-diphenyl-1,3,5-hexatriene (DPH)-based fluorescence anisotropy, Laurdan-based membrane hydration, and differential scanning calorimetry (DSC) studies to cognize the interactions of three bile acid phospholipids, lithocholic acid-phosphocholine (LCA-PC), deoxycholic acid-phosphocholine (DCA-PC), and cholic acid-phosphocholine (CA-PC) with model membranes. These studies revealed that bile acid phospholipids increases membrane fluidity in DCA-PC > CA-PC > LCA-PC order, indicating that induction of membrane fluidity is contingent on the number and positioning of free hydroxyl groups on bile acids. Similarly, DCA-PC causes maximum membrane perturbations due to the presence of a free hydroxyl group, whereas LCA-PC induces gel phase in membranes due to hydrophobic bile acid acyl chain interactions. These DCA-PC-induced membrane perturbations induce a drastic decrease in phase transition temperature (Tm) as determined by calorimetric studies, whereas doping of LCA-PC causes phase transition broadening without change in Tm. Doping of CA-PC induces membrane perturbations and membrane hydration like DCA-PC but sharpening of phase transition at higher doping suggests self-association of CA-PC molecules. Therefore these differential mode of interactions between bile acid phospholipids and model membranes would help in the future for their use in drug delivery. PMID:24079709

Sreekanth, Vedagopuram; Bajaj, Avinash

2013-09-30

365

Equally Spaced?  

NSDL National Science Digital Library

Urbanologists and other types have been interested in the interactions between different groups of people in cities for hundreds of years. There is quite a broad literature on studying different types of communities and public spaces, and this recent paper from the Demos group in the United Kingdom adds to that body of work. This 40-page report was first published in July 2007, and it was authored by Hannah Lownsbrough and Joost Beunderman. As the report's subtitle suggests, it is primarily concerned with presenting a dynamic look at how public places can effectively encourage interaction between diverse communities in urban areas. For this work, the researchers looked at three separate locations in Britain, and this report presents some of their findings on what works well (and not so well) in terms of creating and maintaining high-quality public places. The report is both thoughtful and thorough, and persons with an interest in urban planning, sociology, and related fields will find it quite compelling.

Lownsbrough, Hannah; Beunderman, Joost

2007-07-01

366

Regulation by Polycomb and Trithorax Group Proteins in Arabidopsis  

PubMed Central

Polycomb group (PcG) and trithorax group (trxG) proteins are key regulators of homeotic genes and have crucial roles in cell proliferation, growth and development. PcG and trxG proteins form higher order protein complexes that contain SET domain proteins, with a histone methyltransferase (HMTase) activity, responsible for the different types of lysine methylation at the N-terminal tails of the core histone proteins. In recent years, genetic studies along with biochemical and cell biological analyses in Arabidopsis have enabled researchers to begin to understand how PcG and trxG proteins are recruited to chromatin and how they regulate their target genes and to elucidate their functions. This review focuses on the advances in our understanding of the biological roles of PcG and trxG proteins, their molecular mechanisms of action and further examines the role of histone marks in PcG and trxG regulation in Arabidopsis.

Alvarez-Venegas, Raul

2010-01-01

367

Characterization of the PcCdc42 small G protein from Pneumocystis carinii, which interacts with the PcSte20 life cycle regulatory kinase  

PubMed Central

Pneumocystis carinii (Pc) causes severe pneumonia in immunocompromised hosts. The binding of Pc trophic forms to alveolar epithelial cells is a central feature of infection, inducing the expression and activation of PcSte20, a gene participating in mating, proliferation, and pseudohyphal growth. In related fungi, Ste20 proteins are generally activated by immediate upstream small G proteins of the Cdc42-like family. PcCdc42 has not been previously described in Pneumocystis. To address the potential role of such a G protein in Pneumocystis, PcCdc42 was cloned from a Pc cDNA library. Using the full-length 576-bp PcCdc42 cDNA sequence, a CHEF blot of genomic DNA yielded a single band, providing evidence that this gene is present as a single copy within the genome. The total length of PcCdc42 cDNA was 576 bp with an estimated molecular mass of ?38 kDa. BLASTP analysis demonstrated greater than 80% homology with other fungal Cdc42p proteins. Northern analysis indicated equal mRNA expression in both cystic and trophic life forms. Heterologous expression of PcCdc42 in Saccharomyces cerevisiae (Sc) demonstrated that PcCdc42p was able to restore growth in an ScCdc42? yeast strain. Additional assays with purified PcCdc42 protein demonstrated GTP binding and intrinsic GTPase activity, which was partially but significantly suppressed by Clostridium difficile toxin B, characteristic of Cdc42 GTPases. Furthermore, PcCdc42 protein was also shown to bind to the downstream PCSte20 kinase partner in the presence (but not the absence) of GTP. These data indicate that Pc possesses a Cdc42 gene expressing an active G protein, which binds the downstream regulatory kinase PcSte20, important in Pc life cycle regulation.

Krajicek, Bryan J.; Kottom, Theodore J.; Villegas, Leah

2010-01-01

368

Mechanical shock testing and modeling of PC motherboards  

Microsoft Academic Search

Due to a variety of manufacturing, environmental, shipping, and end-use conditions, personal computer (PC) motherboards and other circuit boards may be subjected to potentially damaging mechanical shock loads. As these loads can lead to product failure, an understanding of the response of circuit boards subjected to suddenly applied loads is necessary. A first step in this direction is to develop

James Pitarresi; Brian Roggeman; Satish Chaparala; Phil Geng

2004-01-01

369

Design of PC-programmable digital hearing-testing device  

Microsoft Academic Search

The design of PC programmable digital hearing-testing device is described in this paper targeting the testing of hearing impairedness in a laboratory environment. It is used to measure the response of each ear at different frequencies and at different sound pressure level (SPL). The device input is the serial 12-bit data and 7-bit control signal from USB connection while the

Jasbir N. Patel; Z. Abid

2005-01-01

370

Compact PC-controlled tester of electric strength  

NASA Astrophysics Data System (ADS)

The tester is a convenient and useful unit for complex damage-free test of current leakage of vacuum and ceramic insulation in a wide range of high voltage. PC-control and processing provide information about the leakage nature and characteristics of the electrodes' surfaces.

Okunev, V. D.; Pozdnyakov, V. I.; Puzanov, S. V.; Yashnov, Y. M.

1994-05-01

371

PC-based Model for Estimating Regional Recruit Markets.  

National Technical Information Service (NTIS)

This thesis develops a personal-computer-based (PC-based) model to utilize research results for the estimation of male high quality (HQ) and high-tech (HITEC) qualified military available (QMA) population. HQ QMA are 17-21 year-old high school graduates s...

A. Bicaksiz

1992-01-01

372

36. View of preset counter (PC) console and tracking console ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

36. View of preset counter (PC) console and tracking console on right, located in MWOC facility in transmitter building no. 102. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

373

Personal Firewall for Pocket PC 2003: Design & Implementation  

Microsoft Academic Search

Personal digital assistants (PDAs) are widely used and becoming indispensable tools of everyday life. Wired or wireless connection enables PDA users to connect to the Internet from any place, making security an extremely important issue in a pervasive computing environment. This paper investigates how to build a personal firewall for PDAs running Pocket PC 2003. This personal firewall allows the

Willy Susilo; Russell James Ang; Cameron Allen George Mcdonald; Jianyong Huang

2005-01-01

374

SEF.ASSISTANT: Shell for Authoring Language SEF.PC.  

ERIC Educational Resources Information Center

This paper describes SEF.ASSISTANT, a special software shell for authoring languages to be used in the development of courseware serving computer based education (CBE). The capabilities of SEF.ASSISTANT are identified: (1) it will generate programs written in the IBM SEF.PC authoring language; (2) it is compatible with external standard software…

Masturzi, Elio R.

375

A Search for AU Mics out to 50pc  

Microsoft Academic Search

Among the numerous M dwarfs sampled by Spitzer in the nearest 25pc, AU Mic remains a unique M dwarf with its debris disk, infrared excess, 12Myr age, flaring, and X-ray activity (Chen et al. 2005, Plavchan et al. 2005, Kalas et al. 2005, Gautier et al., submitted). Plavchan et al. (2005) proposed that stellar wind drag can account for the

George Rieke; Geoff Bryden; J.-F. Lestrade; Peter Plavchan; Karl Staplfeldt; Angelle Tanner; Mike Werner

2007-01-01

376

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

377

Solar wind dependence of the Pc1 wave activity  

Microsoft Academic Search

When we try to understand the origin of Pc1 geomagnetic pulsations, which are the ULF electromagnetic waves in the frequency range between 0.2 and 5 Hz, we normally think of such pulsations as a result of interaction of the solar wind with the Earth's magnetosphere. In other words, the solar wind is considered as a prime cause which leads to

A. Guglielmi; J. Kangas; J. Kultima; A. Potapov

2002-01-01

378

Tablet PC Technology for the Enhancement of Synchronous Distributed Education  

Microsoft Academic Search

In this paper, we describe how tablet PCs are being used at Georgia Tech Savannah (GTS) to improve student learning in a distributed classroom environment. The Tablet PC is an attractive technology for use in synchronous distributed learning environments because of its mobility, and its ability to not only serve as an effective note taking device but also as a

Elliot Moore II; Tristan T. Utschig; Kevin A. Haas; Benjamin Klein; P. D. Yoder; Ying Zhang; Monson H. Hayes

2008-01-01

379

Audio Podcasting in a Tablet PC-Enhanced Biochemistry Course  

ERIC Educational Resources Information Center

This report describes the effects of making audio podcasts of all lectures in a large, basic biochemistry course promptly available to students. The audio podcasts complement a previously described approach in which a tablet PC is used to annotate PowerPoint slides with digital ink to produce electronic notes that can be archived. The fundamentals…

Lyles, Heather; Robertson, Brian; Mangino, Michael; Cox, James R.

2007-01-01

380

Neurite outgrowth in peripherin-depleted PC12 cells  

Microsoft Academic Search

Peripherin is the major neuronal intermedi- ate filament (IF) protein in PC12 cells and both its synthesis and amount increase during nerve growth factor (NGF) promoted neuronal differentiation. To address the question of the biological function of pe- ripherin in neurite initiation we have used an antisense oligonucleotide complementary to the 5' region of pe- ripherin mRNA to specifically inhibit

Carol M. Troy; Lloyd A. Greene; Michael L. Shelanski

1992-01-01

381

METHANE de-NOX for Utility PC Boilers  

Microsoft Academic Search

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 NOâ emissions to 0.15 lb\\/million Btu or less on utility pulverized coal (PC) boilers. This NOâ reduction should be achieved without loss of boiler efficiency or operating stability, and at more than 25%

Bruce Bryan; Serguei Nester; Joseph Rabovitser; Stan Wohadlo

2005-01-01

382

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

383

Advanced cooling system using miniature heat pipes in mobile PC  

Microsoft Academic Search

This paper describes various cooling solutions using heat pipes for cooling a notebook PC. These are: 1) heat pipe with heat spreader plate; 2) hybrid system-i.e., heat pipe with heat sink and fan; and 3) hinged heat pipe system. For heat input of less than 12 W, the thermal resistance measured between the surface of the CPU to ambient was

Thang Nguyen; Masataka Mochizuki; Koichi Mashiko; Yuji Saito; I. Sanciuc; Rex Boggs

2000-01-01

384

Audio Podcasting in a Tablet PC-Enhanced Biochemistry Course  

ERIC Educational Resources Information Center

|This report describes the effects of making audio podcasts of all lectures in a large, basic biochemistry course promptly available to students. The audio podcasts complement a previously described approach in which a tablet PC is used to annotate PowerPoint slides with digital ink to produce electronic notes that can be archived. The…

Lyles, Heather; Robertson, Brian; Mangino, Michael; Cox, James R.

2007-01-01

385

Perceptual Grouping and Visual Enumeration  

PubMed Central

We used lateralized Event-Related Potential (ERP) measures – the N2pc and CDA/SPCN components – to assess the role of grouping by target similarity during enumeration. Participants saw a variable number (0, 1, 2 or 3) of same- or differently-colored targets presented among homogeneous distracters, and performed an enumeration task. Results showed that the N2pc, but not the CDA, was larger for multiple targets of identical color relative to targets of different colors. The findings are interpreted in terms of the effects of grouping on early versus late stages of multiple object processing. Within this framework, they reveal that grouping has an effect on early individuation mechanisms, while later processing mechanisms are less prone to such an influence.

Mazza, Veronica; Caramazza, Alfonso

2012-01-01

386

Space Shuttle.  

ERIC Educational Resources Information Center

The plans for utilizing reusable space shuttles which could replace almost all present expendable launch vehicles are briefly described. Many illustrations are included showing the artists' concepts of various configurations proposed for space shuttles. (PR)

National Aeronautics and Space Administration, Washington, DC.

387

Space Industry.  

National Technical Information Service (NTIS)

The U.S. space industry is a product of Government necessity born of national security imperatives. From its inception, space has provided competitive advantages to the United States in terms of national security, national pride, and technological superio...

J. D. Estridge K. D. Biddlecombe M. Bailey P. F. Frakes R. Campos

2006-01-01

388

Space basic  

NASA Astrophysics Data System (ADS)

In this education video series, 'Liftoff to Learning', astronauts (Bruce Melnick, Thomas Akers, William Shepherd, Robert Cabana, and Richard Richards) describe the historical beginnings of space exploration from the time of Robert H. Goddard (considered the Father of Rocketry), who, in 1929, invented the first propellant rocket, the prototype of modern liquid propellant rockets, up to the modern Space Shuttles. The questions - where is space, what is space, and how do astronauts get to, stay in, and come back from space are answered through historical footage, computer graphics, and animation. The space environment effects, temperature effects, and gravitational effects on the launching, orbiting, and descent of the Shuttles are discussed. Included is historical still photos and film footage of past space programs and space vehicles.

Herbert, Dexter

1991-01-01

389

Groups on transformations in Finslerian spaces.  

National Technical Information Service (NTIS)

The article first appeared in the Internal Reports of the ICTP in 1981. Since then the topic has attracted a large number of authors and several contributions have been made thereafter. Thus, a previous work of the author is revised and up-dated here incl...

R. B. Misra

1993-01-01

390

A Group Exercise in Personal Space.  

ERIC Educational Resources Information Center

|Describes the development of a proxemics exercise from workshops conducted with school teachers and counselors (N=69). Concludes that territoriality involving human beings may be a far broader concept than has been previously thought. (LLL)|

Balgooyen, Theodore J.

1984-01-01

391

METHANE de-NOX FOR UTILITY PC BOILERS  

SciTech Connect

The project seeks to develop and validate a new pulverized coal combustion system to reduce utility PC boiler NO{sub x} emissions to 0.15 lb per million Btu or less without post-combustion flue gas cleaning. Work during previous reporting periods completed the design, installation, shakedown and initial PRB coal testing of a 3-million Btu/h pilot system at BBP's Pilot-Scale Combustion Facility (PSCF) in Worcester, MA. Based on these results, modifications to the gas-fired preheat combustor and PC burner were defined, along with a modified testing plan and schedule. A revised subcontract was executed with BBP to reflect changes in the pilot testing program. Modeling activities were continued to develop and verify revised design approaches for both the Preheat gas combustor and PC burner. Reactivation of the pilot test system was then begun with BBP personnel. During the current reporting period, reactivation of the pilot test system was completed with the modified Preheat gas combustor. Following shakedown of the modified gas combustor alone, a series of successful tests of the new combustor with PRB coal using the original PC burner were completed. NO{sub x} at the furnace exit was reduced significantly with the modified gas combustor, to as low as 150 ppm with only 36 ppm CO (both corrected to 3% O{sub 2}). Concurrent with testing, GTI and BBP collaborated on development of two modified designs for the PC burner optimized to fire preheated char and pyrolysis products from the Preheat gas combustor.

Joseph Rabovitser; Bruce Bryan; Serguei Nester; Stan Wohadlo

2002-10-29

392

The subtilisin/kexin family of precursor convertases. Emphasis on PC1, PC2/7B2, POMC and the novel enzyme SKI-1.  

PubMed

Proopiomelanocortin (POMC) is a precursor to various, bioactive peptides including ACTH, beta LPH, alpha MSH, and beta endorphin (beta END). Processing of POMC at dibasic residues is tissue-specific and is performed by either PC1 alone (resulting in ACTH and beta LPH, anterior pituitary corticotrophes) or by a combination of PC1 and PC2 (yielding alpha MSH and beta END, pituitary neurointermediate lobe and hypothalamus). The PC2-specific binding protein 7B2 is intimately involved in the zymogen activation of proPC2 into PC2. Structure-function studies of these enzymes demonstrated the presence of N- and C-terminal domains, as well as specific amino acids within the catalytic segment that influence the degree of activity of each enzyme and the interaction of PC2 with 7B2. The tissue distribution, plasticity of expression, and the multiple precursors that are differentially cleaved by PC1 and/or PC2, predict a wide array of combinatorial activities of these convertases within the endocrine and neuroendocrine system. The phenotypic consequences of the absence of genetic expression of either PC1 or PC2 are now explored using knockout mice and in human patients suffering from obesity and diabetes. PMID:10816641

Seidah, N G; Benjannet, S; Hamelin, J; Mamarbachi, A M; Basak, A; Marcinkiewicz, J; Mbikay, M; Chrétien, M; Marcinkiewicz, M

1999-10-20

393

Ground-satellite observation of Pc 4 pulsations by MAGDAS/CPMN and ETS-VIII geosynchronous orbit satellite  

NASA Astrophysics Data System (ADS)

Electromagnetic pulsations in ULF range have been studied extensively using ground and satellite observations. However, how Pc 4 pulsations (6.7-22.2 mHz) propagate from the magnetosphere to the ground is not fully understand. Especially the propagation to low latitudes is unclear. We examined data obtained by the ETS-VIII satellite at the geosynchronous orbit (G.M.Lat. -12 degree, G.G.Lon. 146.0 degree) (Koga et al., 2010). We also analyzed ground data of MAGDAS/CPMN (Yumoto and the MAGDAS Group, 2006). The ground data were obtained at high-latitude CHD station (G.M.Lat. 64.9 degree, G.M.Lon. 212.7 degree) and at low-latitude KUJ station (G.M.Lat. 26.1 degree, G.M.Lon. 203.0 degree). The magnetic longitudes of these ground stations are almost same as that of the ETS-VIII. Pc 4 events at ETS-VIII were selected by an automated routine using FFT method which was developed by Takahashi and Ukhorskiy (2007). These Pc 4 events were classified into 2 types. One type is a poloidal Pc 4, in which Hp (northward) component is dominant. Another type is a toroidal mode, in which Hn (eastward) component is dominant. About 10 % of the poloidal/toroidal Pc 4 pulsations, the peak frequency is identical with that of ground Pc 4 pulsations, and the coherence between pulsations observed aboard ETS-VII and on the ground stations is high at the peak frequencies. Thus, about 10 % of the poloidal/toroidal Pc 4 in the magnetosphere can be concluded to transmit to high-latitude ground stations as well as low-latitude stations. For such Pc 4 events, H (horizontal northward) and D (horizontal eastward) components at CHD showed higher amplitude (delta(H)/delta(Hn) = 6.8, delta(H)/delta(Hp) = 10.8, delta(D)/delta(Hn) = 6.8, delta(D)/delta(Hp) = 7.4) than that at the geosynchronous orbit. On the other hand, H and D components at KUJ was attenuated considerably (delta(H)/delta(Hn) = 0.66, delta(H)/delta(Hp) = 0.89, delta(D)/delta(Hn) = 0.35, delta(D)/delta(Hp) = 0.37).

Ikeda, A.; Yumoto, K.; Koga, K.; Obara, T.; Baishev, D. G.; Shevtsov, B. M.; Uozumi, T.; Abe, S.; Shishime, A.

2011-12-01

394

Multipurpose Spaces  

ERIC Educational Resources Information Center

|The concept of multipurpose spaces in schools is certainly not new. Especially in elementary schools, the combination of cafeteria and auditorium (and sometimes indoor physical activity space as well) is a well-established approach to maximizing the use of school space and a school district's budget. Nonetheless, there continue to be refinements…

Gordon, Douglas

2010-01-01

395

Space Froggy  

NSDL National Science Digital Library

Help Captain Space Froggy and his family escape from a top secret lab located on the Space Station "Fluffy" above the Earth. To escape they must first cross the busy docking ramp and then traverse deep space landing on one of the transporter pads.

2010-01-01

396

Space Suit.  

National Technical Information Service (NTIS)

A pressure suit for high altitude flights, particularly space missions is reported. The suit is designed for astronauts in the Apollo space program and may be worn both inside and outside a space vehicle, as well as on the lunar surface. It comprises an i...

A. J. Kenneway G. P. Durney L. F. Shepard M. C. Case R. C. Wise

1973-01-01

397

Establishment and characterization of methylmercury-resistant PC12 cell line.  

PubMed Central

Methylmercury (MeHg)-resistant sublines of rat pheochromocytoma (PC12) cells were isolated by repeated exposure to stepwise increased concentrations of MeHg. One of the sublines (PC12/TM) showed an 8- to 10-fold increase in resistance to MeHg compared with parent PC12 cells on the basis of the concentration required for 50% inhibition (IC50) of growth. PC12/TM cells accumulated smaller amounts of MeHg than parent PC12 cells. This reduction in MeHg accumulation in PC12/TM cells resulted from slow uptake and rapid efflux. The intracellular glutathione (GSH) level in PC12/TM cells was four times higher than that of PC12 cells. Pretreatment of PC12/TM cells with buthionine sulfoximine, which decreased the GSH level to that of the parent PC12 cells, increased the sensitivity of PC12/TM cells to MeHg. A close correlation between the MeHg accumulation and MeHg sensitivity was found among seven sublines of PC12 cells and parent PC12 cell line. The GSH level in PC12 sublines was also correlated with their sensitivity to MeHg.

Miura, K; Clarkson, T W; Ikeda, K; Naganuma, A; Imura, N

1994-01-01

398

Loop spaces and homotopy operations  

Microsoft Academic Search

The question of whether a given H-space X is, up to homotopy, a loop space has been studied from a variety of viewpoints. Here we address this question from the aspect of homotopy operations, in the classical sense of operations on homotopy groups. First, we show how an H-space structure on X can be used to define the action of

David Blanc

1998-01-01

399

Comparative analysis of expression of the proprotein convertases furin, PACE4, PC1 and PC2 in human lung tumours.  

PubMed Central

Proprotein convertases mediate the production of a variety of peptidic mitogens by limited proteolysis of their precursors. These proteases may also participate in the autocrine production of such mitogens by cancer cells and thus contribute to the unchecked proliferation of these cells. As a step towards defining this contribution, we have examined the levels of four convertase mRNAs in human lung neoplasms using semiquantitative Northern blot analysis. Furin mRNA was expressed in all the tumours; its level in squamous cell carcinomas and adenocarcinomas was on average about threefold higher than in small-cell lung carcinomas (SCLCs). PACE4 transcripts were detected in eight of 14 adenocarcinomas and in seven of 17 squamous cell carcinomas; they were detectable in only two of seven SCLCs. PC1 mRNA was undetected in squamous cell carcinomas and in all but two adenocarcinomas; it was present in four of six SCLCs. PC2 mRNA was found in two adenocarcinomas, in one squamous cell carcinoma and in five of seven SCLCs. This preliminary survey indicates that SCLCs often carry more mRNA for the endocrine convertases PC1 and PC2 and less mRNA for the more ubiquitous furin and PACE4, suggesting inverse roles of these convertases in the development of this neoplasm. Images Figure 1 Figure 2

Mbikay, M.; Sirois, F.; Yao, J.; Seidah, N. G.; ChrA(C)tien, M.

1997-01-01

400

LT and MLT Dependencies of Pc 4 Amplitudes at CPMN Conjugate Stations  

NASA Astrophysics Data System (ADS)

Amplitude of magnetic pulsations observed on the ground can be expressed by B=A F(MLT) f(LT) ? where A is amplitude of source wave, F(MLT) shows MLT dependence of amplitude, f(LT) is a function of ionospheric conductivities at local time of station, and ? is a geological factor at station. In order to clarify F(MLT) and f(LT) of Pc 4 pulsations observed at the Circum-pan Pacific Magnetometer Network (CPMN) conjugate stations, we analyzed the CPMN magnetic data at Chokurdakh (CHD; M.lat.=64.67 deg.,M.lon.=212.12 deg., L=5.46), Kotzebue (KOT; 64.52, 249.72, 5.40), and Macquarie Isl. (MCQ; -64.50, 247.84, 5.40) during the interval of 15 - 17 September, 1994. Contaminated information of F(MLT) and f(LT) can be distributed by estimate the power ratio of CHD-KOT and CHD-MCQ. If we use the magnetic stations in the one-hemisphere, it is difficult to separate F(MLT) and f(LT). However, if we can analyzed data from the magnetic conjugate stations, the f(LT) can be extracted from the observed data, because F(MLT) at the conjugate points must be almost the same. From the analysis, the following results are obtained. (1) The F(MLT) of Pc 4 shows maximum in the prenoon sector and minimum in the afternoon sector. The maximum power is more than 3 times stronger than the minimum power. (2) The f(LT) of Pc 4 has the maximum around 6 and 18 LT, and minimum around 12 LT. The maximum power is 1.59 times stronger than the minimum power. In the present paper, we will compare the F(MLT) of Pc 4 on the ground and in space, and also discuss the LT dependence of obtained f(LT) on the ground.

OBANA, Y.; Yoshikawa, A.; Morris, R. J.; Fraser, B. J.; Olson, J. V.; Solovyev, S. I.; Yumoto, K.

2001-12-01

401

Global nature of Pc 5 magnetic pulsation during the WHI observation campaign  

NASA Astrophysics Data System (ADS)

In conjunction with the activities of IHY(International Heliophysical Year), an international observation campaign was planned and carried out from March 20 to April 16 of 2008. The name of this campaign is Whole Heliosphere Interval (WHI). During WHI, the nations of the world worked together to collect relevant scientific data. As a result, there now exists an exceptionally good data set of multi-point ground-based and satellite magnetometer data for this time frame. There were no clear and outstanding geomagnetic storms during WHI, but there were some moderate geomagnetically active moments. For example, on March 26, Dst index decreased from 25 nT to -41 nT for 10 hours(1000 -1900 UT). The amplitude of Pc 5 pulsation in the frequency band between 1.67 and 6.67 mHz at the MAGDAS stations increased for few days after March 26. Using magnetometer data obtained globally from ULTIMA(Ultra Large Terrestrial International Magnetic Array) stations, we will investigate the occurrence and wave characteristics(amplitude, period and phase) of Pc 5 pulsations. Particularly high-latitude Pc 5 observed at THEMIS (the Time History of Events and Macroscopic Interactions during Substorms), CARISMA(Canadian Array for Realtime Investigations of Magnetic Activity) and McMaC (Mid-continent Magnetoseismic Chain) stations will be compared with equatorial-latitude Pc 5 observed at MAGDAS stations(TIR, DAV, YAP, ANC, EUS, ILR, and UT=LT+5h, +8h, +9h, -5h, -2h and 0h, respectively). Acknowledgment: MAGDAS data used in this paper were obtained in mutual collaborations with the following representatives of various organizations; Prof. Archana Bhattacharya(Indian Institute of Geomagnetism, TIR), Fr. Daniel McNamara(Manila Observatory, DAV), Dr. David Aranug(Weather Service Office YAP, YAP), Dr. Ronald Woodman Pollitt(Instituto Geofisico del Peru, ANC), Dr. Severino L. G. Dutra(Brazilian National Space Research Institute (INPE), EUS), Dr. A. Babatunde Rabiu(Federal University of Technology, ILR).

Fujimoto, A.; Tokunaga, T.; Abe, S.; Uozumi, T.; Yoshikawa, A.; Yumoto, K.; Group, M.

2008-12-01

402

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

2013-08-23

403

Mutations in the Glucose-6-Phosphatase-? (G6PC) Gene that Cause Type Ia Glycogen Storage Disease  

PubMed Central

Glucose-6-phosphatase-? (G6PC) is a key enzyme in glucose homeostasis that catalyzes the hydrolysis of glucose-6-phosphate to glucose and phosphate in the terminal step of gluconeogenesis and glycogenolysis. Mutations in the G6PC gene, located on chromosome 17q21, result in glycogen storage disease type Ia (GSD-Ia), an autosomal recessive metabolic disorder. GSD-Ia patients manifest a disturbed glucose homeostasis, characterized by fasting hypoglycemia, hepatomegaly, nephromegaly, hyperlipidemia, hyperuricemia, lactic acidemia, and growth retardation. G6PC is a highly hydrophobic glycoprotein, anchored in the membrane of the endoplasmic reticulum with the active center facing into the lumen. To date, 54 missense, 10 nonsense, 17 insertion/deletion, and 3 splicing mutations in the G6PC gene have been identified in more than 550 patients. Of these, 50 missense, 2 nonsense, and 2 insertion/deletion mutations have been functionally characterized for their effects on enzymatic activity and stability. While GSD-Ia is not more prevalent in any ethnic group, mutations unique to Caucasian, oriental, and Jewish populations have been described. Despite this, GSD-Ia patients exhibit phenotypic heterogeneity and a stringent genotype-phenotype relationship does not exist.

Chou, Janice Y.; Mansfield, Brian C.

2008-01-01

404

MIB-1 and PC-10 immunostaining for the assessment of proliferative activity in primary acquired melanosis without and with atypia  

PubMed Central

AIMS—To compare the proliferative activity of intraepithelial melanocytes in primary acquired melanosis (PAM) without atypia and PAM with atypia by immunohistochemical staining for the Ki-67 antigen and the proliferating cell nuclear antigen (PCNA).?METHODS—Formalin fixed, paraffin embedded sections from 35 archival specimens of PAM without atypia (n=19) and with atypia (n=16) were studied by immunostaining with MIB-1 and PC-10 monoclonal antibodies that react with the Ki-67 antigen and PCNA respectively. The results were calculated as the mean number of positive cells per eyepiece grid. All specimens were evaluated by two masked observers, and the interobserver reproducibility was assessed.?RESULTS—The means of the positive cell count in PAM with atypia were significantly higher compared with PAM without atypia for both observers, in both the PC-10 and the MIB-1 stained sections. In a linear least square model that estimated the interobserver and between group variation, the difference of MIB-1 and PC-10 positive cell count between PAM without and with atypia remained highly significant. The difference between the observers was not significant.?CONCLUSIONS—Immunostaining with MIB-1 and PC-10 demonstrated that PAM with atypia has higher proliferative activity than PAM without atypia. This method was found to be reproducible between different observers.?? Keywords: primary acquired melanosis; immunostaining; atypia

Chowers, I.; Livni, N.; Solomon, A.; Zajicek, G.; Frucht-Pery, J.; Folberg, R.; Pe'er, J.

1998-01-01

405

Astaxanthin Suppresses MPP+-Induced Oxidative Damage in PC12 Cells through a Sp1/NR1 Signaling Pathway  

PubMed Central

Objective: To investigate astaxanthin (ATX) neuroprotection, and its mechanism, on a 1-methyl-4-phenyl-pyridine ion (MPP+)-induced cell model of Parkinson’s disease. Methods: Mature, differentiated PC12 cells treated with MPP+ were used as an in vitro cell model. The MTT assay was used to investigate cell viability after ATX treatment, and western blot analysis was used to observe Sp1 (activated transcription factor 1) and NR1 (NMDA receptor subunit 1) protein expression, real-time PCR was used to monitor Sp1 and NR1 mRNA, and cell immunofluorescence was used to determine the location of Sp1 and NR1 protein and the nuclear translocation of Sp1. Results: PC12 cell viability was significantly reduced by MPP+ treatment. The expression of Sp1 and NR1 mRNA and protein were increased compared with the control (p < 0.01). Following co-treatment with ATX and MPP+, cell viability was significantly increased, and Sp1 and NR1 mRNA and protein were decreased, compared with the MPP+ groups (p < 0.01). In addition, mithracycin A protected PC12 cells from oxidative stress caused by MPP+ by specifically inhibiting the expression of Sp1. Moreover, cell immunofluorescence revealed that ATX could suppress Sp1 nuclear transfer. Conclusion: ATX inhibited oxidative stress induced by MPP+ in PC12 cells, via the SP1/NR1 signaling pathway.

Ye, Qinyong; Zhang, Xiaodong; Huang, Bixia; Zhu, Yuangui; Chen, Xiaochun

2013-01-01

406

Space Communication  

NASA Astrophysics Data System (ADS)

As the space era approaches, the importance of including space science in the general curriculum and communicating space science to the general public is becoming extremely important. The paper, points out that the inclusion of more space education in the school curriculum and to the general public will increase awareness and interest in the new developments of space exploration. The paper covers some of the many science communication projects under taken by students in the UK. One such success was the contribution to National Science Week by the University of Leicester in conjunction with UK Students for the Exploration and Development of Space (UKSEDS - a national body of students promoting space education). Children between the ages of 9-12 were taught about the solar system using enjoyable experiments. The paper will also cover other UKSEDS activities and projects. On a more worldwide scale `Under African Skies' is a fairly new and immensely exciting project (part of Cosmos Education): the participants last year including UKSEDS members travelled from school to school in Africa helping teachers and taking part in classes, including many in astronomy and physics. The paper also explains the benefits of the National Space Centre in the UK, the involvement of the University of Leicester in SSETI (Student Space Exploration and Technology Initiative) and Space School.

Patel, Bhavini

2002-01-01

407

Pc3 geomagnetic pulsations at near-equatorial latitudes at the initial phase of the magnetic storm of April 5, 2010  

NASA Astrophysics Data System (ADS)

An analysis of sampled 1-s observational data on geomagnetic pulsations within the Pc3 range on the INTERMAGNET network of near-equatorial and low-latitude observatories spaced over longitude during the initial phase of a moderate magnetic storm (April 5-7, 2010) was carried out for the first time. The obtained results were compared with magnetic observations at the low-latitude Chambon-la-Foret (CLF) and subauroral Kerguelen (PAF) observatories, as well as with observations at six Australian observatories located at low and middle latitudes. Two time intervals were studied in detail: the sudden commencement ( SC) of the storm and the onset of the great global substorm. In the first interval, maximal amplitudes of near-equatorial pulsations were observed in the near-noon sector; in the second interval, in the near-midnight sector. The dynamics of the spectral structure of Pc3 pulsations in the considered events was shown to be different in spite of the fact that in both cases an amplification of waves was observed in two close spectral bands of the Pc3 spectrum: ˜20-30 and ˜30-40 mHz. The considered Pc3 pulsations were characterized by very small azimuthal wavenumbers (0.5 and less). Possible generation mechanisms for the observed Pc3 pulsations are discussed.

Kleimenova, N. G.; Zelinskii, N. R.; Kozyreva, O. V.; Malysheva, L. M.; Solov'ev, A. A.; Bogoutdinov, Sh. R.

2013-05-01

408

Space Resources Roundtable 2  

NASA Astrophysics Data System (ADS)

Contents include following: Developing Technologies for Space Resource Utilization - Concept for a Planetary Engineering Research Institute. Results of a Conceptual Systems Analysis of Systems for 200 m Deep Sampling of the Martian Subsurface. The Role of Near-Earth Asteroids in Long-Term Platinum Supply. Core Drilling for Extra-Terrestrial Mining. Recommendations by the "LSP and Manufacturing" Group to the NSF-NASA Workshop on Autonomous Construction and Manufacturing for Space Electrical Power Systems. Plasma Processing of Lunar and Planetary Materials. Percussive Force Magnitude in Permafrost. Summary of the Issues Regarding the Martian Subsurface Explorer. A Costing Strategy for Manufacturing in Orbit Using Extraterrestrial Resources. Mine Planning for Asteroid Orebodies. Organic-based Dissolution of Silicates: A New Approach to Element Extraction from LunarRegohth. Historic Frontier Processes Active in Future Space-based Mineral Extraction. The Near-Earth Space Surveillance (NIESS) Mission: Discovery, Tracking, and Characterization of Asteroids, Comets, and Artificial Satellites with a microsatellite. Privatized Space Resource Property Ownership. The Fabrication of Silicon Solar Cells on the Moon Using In-Situ Resources. A New Strategy for Exploration Technology Development: The Human Exploration and Development of Space (HEDS) Exploratiori/Commercialization Technology Initiative. Space Resources for Space Tourism. Recovery of Volatiles from the Moon and Associated Issues. Preliminary Analysis of a Small Robot for Martian Regolith Excavation. The Registration of Space-based Property. Continuous Processing with Mars Gases. Drilling and Logging in Space; An Oil-Well Perspective. LORPEX for Power Surges: Drilling, Rock Crushing. An End-To-End Near-Earth Asteroid Resource Exploitation Plan. An Engineering and Cost Model for Human Space Settlement Architectures: Focus on Space Hotels and Moon/Mars Exploration. The Development and Realization of a Silicon-60-based Economy in CisLunar Space. Our Lunar Destiny: Creating a Lunar Economy. Cost-Effective Approaches to Lunar Passenger Transportation. Lunar Mineral Resources: Extraction and Application. Space Resources Development - The Link Between Human Exploration and the Long-term Commercialization of Space. Toward a More Comprehensive Evaluation of Space Information. Development of Metal Casting Molds by Sol-Gel Technology Using Planetary Resources. A New Concept in Planetary Exploration: ISRU with Power Bursts. Bold Space Ventures Require Fervent Public Support. Hot-pressed Iron from Lunar Soil. The Lunar Dust Problem: A Possible Remedy. Considerations on Use of Lunar Regolith in Lunar Constructions. Experimental Study on Water Production by Hydrogen Reduction of Lunar Soil Simulant in a Fixed Bed Reactor.

Ignatiev, A.

2000-01-01

409

Polycomb group genes control pattern formation in plant seed  

Microsoft Academic Search

Transcriptional activators of the Trithorax group (TRX-G) and repressors of the Polycomb group (Pc-G) are involved in multiple aspects of embryogenesis in Drosophila and the mouse [1, 2] and appear to have a conserved role in the zygotic control of the development of the anterior-posterior axis [3, 4, 5]. In the model plant Arabidopsis, three Pc-G genes have been isolated

Mikael Blom Sørensen; Abdul M. Chaudhury; Hélène Robert; Estelle Bancharel; Frédéric Berger

2001-01-01

410

Identification and Functional Characterization of Polycomb Group Complexes in Drosophila  

Microsoft Academic Search

Polycomb group (PcG) and trithorax group (trxG) proteins were first discovered\\u000ain Drosophila as repressors and activators of homeotic (HOX) genes, a set of\\u000atranscription factors that specify cell identity along the anteroposterior axis of segmented\\u000aanimals. Subsequent work has shown that PcG and trxG proteins form multimeric\\u000acomplexes that are not required to initiate the regulation of HOX genes,

A. Lagarou

2009-01-01

411

Implementation of WASP-III on an IBM PC  

SciTech Connect

Argonne National Laboratory (ANL) is currently developing a microcomputer-based energy planning package entitled ENergy and Power Evaluation Program (ENPEP). As presently constructed, ENPEP consists of six analytic modules that can be run sequentially or independently: (1) macroeconomic analysis, (2) energy demand forecasting, (3) integrated energy demand/supply analysis, (4) electric load forecasting, (5) expansion planning for electrical generating systems, and (6) impacts of alternative supply systems. The Wien Automatic System Planning Package (WASP-III) is the fifth module of ENPEP and forms the heart of the ENPEP analytic capability. The experience in converting WASP-III to the IBM PC is reviewed and some recommendations for good performance on the PC are given. Finally, a few suggestions are presented for WASP improvements from the point of view of the user of the personal computer version of WASP.

Buehring, W.A.; Huber, C.C.; Hamilton, B.P.

1985-01-01

412

METHANE de-NOX for Utility PC Boilers  

SciTech Connect

Large-scale combustion tests with caking bituminous coal has stopped. This stoppage has come about due to limitations in current funding available to continue large scale research and development activities at Riley Power's Commercial Burner Test Facility (CBTF) of the PC Preheat technology. The CBTF was secured and decommissioned in the previous quarter; work this quarter work completed the securing the proper disposition of all PC Preheat experimental equipment at the PSCF and CBTF and completing negotiations with AES Westover (a power plant in Johnson City, New York) to accept 130 tons of residual PRB test coal in storage. The coal transport to Westover occurred at the end of August. GTI was granted a no-cost time extension through September 2005; immediate efforts are focused on completing a draft final report, which is due in October 31, 2005 and the final report in December.

Joseph Rabovitser; Serguei Nester; Stan Wohadlo

2005-09-30

413

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

414

Space extreme design  

Microsoft Academic Search

This paper is an introduction to the following five articles, that have been conceived together as one chapter on habitability\\u000a consideration for outer space habitations. Those contributions are made from authors in different fields, cultures and countries\\u000a working with the Extreme-Design.eu research group. Projects, theories and requirements are referred to the context of outer\\u000a space habitats, where for the love

Irene Lia Schlacht

2011-01-01

415

Normal Biconformal Spaces  

Microsoft Academic Search

A new 8-dimensional conformal gauging avoids the unphysical size change,\\u000athird order gravitational field equations, and auxiliary fields that prevent\\u000ataking the conformal group as a fundamental symmetry. We give the structure\\u000aequations, gauge transformations and intrinsic metric structure for the new\\u000abiconformal spaces. We prove that a torsion-free biconformal space with exact\\u000aWeyl form, closed dilational curvature and trace-free

James T. Wheeler

1997-01-01

416

Preparation and characterization of PC\\/SBR heterogeneous cation exchange membrane filled with carbon nano-tubes  

Microsoft Academic Search

Polycarbonate (PC)\\/styrene–butadiene–rubber (SBR) blend heterogeneous cation exchange membranes were prepared by solution casting technique using tetrahydrofuran as solvent and cation exchange resin powder as functional groups agent. Multi-walled carbon nano-tube (MWCNT) was selected as inorganic filler additive. The effect of additive loading on properties of prepared membranes was studied. Sonication was used to help in appropriate dispersion of particles in

S. M. Hosseini; S. S. Madaeni; A. R. Khodabakhshi

2010-01-01

417

SIMION PC\\/PS2 electrostatic lens design program  

Microsoft Academic Search

SIMION PC\\/PS2 4.02 is a personal computer program for designing and analyzing charged particle (ions and electrons) lenses, ion transport systems, and various types of mass spectrometers and surface probes that utilize charged particles. The modification of an existing design or the generation of a completely new one is performed interactively with a graphics screen and mouse. Once the geometry

D. A. Dahl; J. E. Delmore; A. D. Appelhans

1990-01-01

418

PC1 with a broad frequency spectrum — “Goose pulsations”  

Microsoft Academic Search

Geomagnetic pulsations in the frequency range of Pc1 pearl waves with the dynamic spectra having a very narrow spectrum width\\u000a at the beginning of the event and a very broad spectrum width (?f\\/f0 ? 1) in the later part of the event are analyzed. One of the observed events shown by the dynamic spectrum resembles a goose\\u000a with the beak

Felix Z. Feygin; Karel Prikner; Jorma Kangas

2009-01-01

419

DEVELOPMENT OF PC BASED FIELD CONTROLLER WITH LINUX  

Microsoft Academic Search

In SPring-8 storage ring control system, VMEbus systems with real-time UNIX(HP-RT) are used as front-end controllers. For increasing requirements of temporary measurements, it is useful to introduce inexpensive I\\/O controllers. Linux based PC system was adopted as a supplement system with the same functionality as that of the VMEs. Control software running on the VME system was migrated to Linux

T. Masuda; T. Fukui; M. Kodera; R. Tanaka; A. Yamashita

420

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.

Tristram-Nagle, Stephanie; Kim, Dong Joo; Akhunzada, Nadia; Kucerka, Norbert; Mathai, John C.; Katsaras, John; Zeidel, Mark; Nagle, John F.

2010-01-01

421

VALIDATION AND VERIFICATION OF THE MTR_PC THERMOHYDRAULIC PACKAGE  

Microsoft Academic Search

The MTR_PC v2.6 is a computational package developed for research reactor design and calculation. It covers three of the main aspects of a research reactor: neutronic, shielding and thermohydraulic. In this work only the thermohydraulic package will be covered, dealing with verification and validation aspects. The package consists of the following steady state programs: CAUDVAP 2.60 for the hydraulic calculus,

Alicia Doval

422

Ionic regulation of endonuclease activity in PC12 cells.  

PubMed Central

We have investigated the Ca2+ dependency of DNA degradation into nucleosome-sized fragments in intact chromaffin-like PC12 cells and PC12 nuclear fractions. In intact cells we were unable to trigger DNA fragmentation by inducing either transient or sustained elevations of cytoplasmic Ca2+ ([Ca2+]i) with the Ca2+ ionophore ionomycin. On the contrary, DNA fragmentation was induced in intact cells by the intracellular Zn2+ chelator NNN'N'-tetrakis-(2-pyridylmethyl)ethylenediamine (TPEN). To characterize further PC12 cell endonuclease activity, we then investigated digestion by purified PC12 cell fractions of exogenously added plasmids. In nuclear fractions two endonuclease activities were identified: an acidic (pH 5.0) endonuclease activity that was fully Ca2+- and Mg(2+)-independent; and a neutral (pH 7.6) endonuclease activity that was Ca(2+)-independent but Mg(2+)-dependent. Both endonuclease activities were inhibited by Zn2+. Nuclear membrane permeabilization greatly enhanced plasmid digestion at pH 7.6, but not at pH 5.0. This suggests that neutral endonuclease was located in a membrane-bound compartment, whereas acidic endonuclease was freely accessible to the substrate even in the presence of an intact nuclear membrane. In intact nuclei, digestion of genomic DNA could not be triggered by increasing the bivalent cation composition of the medium. On the contrary, in hypotonic medium we observed a large spontaneous nucleolytic DNA degradation that was increased by Zn2+ chelation. However, an acidic pH shift was a potent stimulus for DNA fragmentation in isotonic as well as hypotonic medium. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 7

Villalba, M; Ferrari, D; Bozza, A; Del Senno, L; Di Virgilio, F

1995-01-01

423

Operating a Geiger Müller tube using a PC sound card  

Microsoft Academic Search

In this paper, a simple MATLAB-based PC program that enables the computer to function as a replacement for the electronic scalar-counter system associated with a Geiger-Müller (GM) tube is described. The program utilizes the ability of MATLAB to acquire data directly from the computer sound card. The signal from the GM tube is applied to the computer sound card via

A. A. Azooz

2009-01-01

424

Manganese oxidation state mediates toxicity in PC12 cells  

Microsoft Academic Search

The role of the manganese (Mn) oxidation state on cellular Mn uptake and toxicity is not well understood. Therefore, undifferentiated PC12 cells were exposed to 0–200 ?M Mn(II)–chloride or Mn(III)–pyrophosphate for 24 h, after which cellular manganese levels were measured along with measures of cell viability, function, and cytotoxicity (trypan blue exclusion, medium lactate dehydrogenase (LDH), 8-isoprostanes, cellular ATP, dopamine,

S. H.. Reaney; D. R. Smith

2005-01-01

425

METHANE de-NOX FOR UTILITY PC BOILERS  

Microsoft Academic Search

The project seeks to develop and validate a new pulverized coal combustion system to reduce utility PC boiler NOx emissions to 0.15 lb\\/million Btu or less without post-combustion flue gas cleaning. Work during previous reporting periods completed the design, installation, shakedown and initial PRB coal testing of a 3-million Btu\\/h pilot system at BBP's Pilot-Scale Combustion Facility (PSCF) in Worcester,

Joseph Rabovitser; Bruce Bryan; Serguei Nester; Stan Wohadlo

2002-01-01

426

METHANE de-NOX FOR UTILITY PC BOILERS  

Microsoft Academic Search

The project seeks to develop and validate a new pulverized coal combustion system to reduce utility PC boiler NOâ emissions to 0.15 lb per million Btu or less without post-combustion flue gas cleaning. Work during previous reporting periods completed the design, installation, shakedown and initial PRB coal testing of a 3-million Btu\\/h pilot system at BBP's Pilot-Scale Combustion Facility (PSCF)

Joseph Rabovitser; Bruce Bryan; Serguei Nester; Stan Wohadlo

2002-01-01

427

METHANE de-NOX FOR UTILITY PC BOILERS  

Microsoft Academic Search

The project seeks to develop and validate a new pulverized coal combustion system to reduce utility PC boiler NOâ emissions to 0.15 lb\\/million Btu or less without post-combustion flue gas cleaning. Work during previous reporting periods completed the design, installation, shakedown and initial PRB coal testing of a 3-million Btu\\/h pilot system at BBP's Pilot-Scale Combustion Facility (PSCF) in Worcester,

Joseph Rabovitser; Bruce Bryan; Serguei Nester; Stan Wohadlo

2002-01-01

428

METHANE de-NOX FOR UTILITY PC BOILERS  

Microsoft Academic Search

The project seeks to develop and validate a new pulverized coal combustion system to reduce utility PC boiler NOx emissions to 0.15 lb per million Btu or less without post-combustion flue gas cleaning. Work during previous reporting periods completed the design, installation, shakedown and initial PRB coal testing of a 3-million Btu\\/h pilot system at BBP's Pilot-Scale Combustion Facility (PSCF)

Joseph Rabovitser; Bruce Bryan; Serguei Nester; Stan Wohadlo

2002-01-01

429

Manufacturing resource planning on a PC local area network  

Microsoft Academic Search

This paper details a large APL programming project of 12 man years. An integrated software system structured on the principles of MRP (manufacturing resource planning) was implemented by a Bristol-Myers in house team for use in a new manufacturing facility.The system applies off-the-shelf technology in innovative ways, using STSC APL*PLUS\\/PC as the only programming language, to build a very sophisticated

H. Clark Kee; Roy L. Post

1986-01-01

430

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); Jay A. Blundon (Rhodes College;Department of Biology REV); Elizabeth M. Adler (American Association for the Advancement of Science;Science's STKE REV)

2007-07-10

431

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.

Fabbro, Alessandra; Skorinkin, Andrei; Grandolfo, Micaela; Nistri, Andrea; Giniatullin, Rashid

2004-01-01

432

UPDATION OF ECR POWER SUPPLY CONTROLS TO DISTRIBUTED PC ENVIRONMENT  

Microsoft Academic Search

Controls of the ECR source and the beam-handling elements for injection of the heavy ions into the cyclotron, are being shifted to the central control room, in phases. The work constitutes a part of the retro-fitted distributed computerization of the Cyclotron. A Pentium, Win95 PC working in the ECR front-end takes care of the above power supplies controls. Existing CAMAC

Tushar K. Das; Amitava Roy; Sushanta K. Pal; S. Dasgupta

433

A compact PC-based X-ray imaging system  

Microsoft Academic Search

A compact, portable PC-based X-ray imaging system has been developed based on a 2D silicon microstrip sensor and particle physics readout electronics. The sensor is housed in a specially built hybrid, which also hosts the front-end electronics. The control and the readout electronics used are based on the standard PCI and PMC architectures and were originally developed for High Energy

A. Asimidis; I. Evangelou; P. Kokkas; N. Manthos; F. Triantis; R. D. Speller; G. Hall; P. F. Van der Stelt

2007-01-01

434

Learning Spaces  

NSDL National Science Digital Library

This website from EDUCAUSE includes the full text of the book Learning Spaces, edited by Diana G. Oblinger. Space, whether physical or virtual, can have a significant impact on learning. Learning Spaces focuses on how learner expectations influence such spaces, the principles and activities that facilitate learning, and the role of technology from the perspective of those who create learning environments: faculty, learning technologists, librarians, and administrators. Information technology has brought unique capabilities to learning spaces, whether stimulating greater interaction through the use of collaborative tools, videoconferencing with international experts, or opening virtual worlds for exploration. This e-book represents an ongoing exploration as we bring together space, technology, and pedagogy to ensure learner success.

Oblinger, Diana

2010-07-12

435

Modulation of TEC/GPS by ULF Pc5 waves  

NASA Astrophysics Data System (ADS)

The intriguing effect was found while analyzing the small-scale variations of total electron content (TEC) derived from global positioning system (GPS) signals. We have searched for a possible response in TEC variations to intense global Pc5 pulsations with period about few mHz during the recovery phase of the strong magnetic storm on Oct. 31, 2003. Earlier studies demonstrated that the GPS-TEC technique is a very 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 unexpectedly sensitive to ULF waves as well. During periods with intense Pc5 geomagnetic wave activity very clear pulsations with the same periodicity were found in the TEC data from high-latitude GPS receiving stations in Scandinavia and Arctic Canada. Moreover, the relative amplitude of TEC periodic fluctuations was about an order of magnitude larger than relative amplitude of geomagnetic variations. So far, the effect of TEC modulation by Pc5 waves is not well understood and is still a challenge for the MHD wave theory.

Pilipenko, Vyacheslav; Belakhovsky, Vladimir; Murr, David; Teramoto, Mariko

2013-04-01

436

Spaced Out  

NSDL National Science Digital Library

Students are introduced to the space environment, learning about the major differences between the environment on Earth and that of outer space (atmosphere, radiation, microgravity) â and the engineering challenges that arise because of these differences. To prepare students for the upcoming lessons on the human body, they are challenged to think about how their bodies would change and adapt in the unique environment of space.

Integrated Teaching And Learning Program

437

Conceptual Spaces  

Microsoft Academic Search

Spaces exist in the mind as well as on land and sea. They cannot be seen, or traversed by ship or on foot, not even with seven-league\\u000a boots. For they are abstract spaces, or styles of thinking. But although the geographer's methods of dealing with terrestrial\\u000a space do not reliably apply to the conceptual realm, there are other methods with

Margaret A. Boden

438

Noncommutative Spaces  

Microsoft Academic Search

In this chapter we present some of the basic concepts needed to describe noncommutative spaces and their topological and geometrical\\u000a features. We therefore complement the previous chapters where noncommutative spaces have been described by the commutation\\u000a relations of their coordinates. The full algebraic description of ordinary (commutative) spaces requires the completion of\\u000a the algebra of coordinates into a \\u000a C*<\\/font\\u000a>C^\\\\star

Fedele Lizzi

2009-01-01

439

PROFIT-PC: a program for estimating maximum net revenue from ...  

Treesearch

Description: PROFIT-PC is a menu driven, interactive PC (personal computer) program that estimates optimum product mix and ... select from 10 yarding or skidding machines to estimate stump-to-mill harvesting costs. ... Language: English.

440

Chapter: Reflection groups  

Microsoft Academic Search

This chapter is concerned with the theory of finite reflection groups, that is, finite groups generated by reflections in a real or complex vector space. This is a rich theory, both for intrinsic reasons and as far as applications in other mathematical areas or mathematical physics are concerned. The origin of the theory can be traced back to the ancient

MEINOLF GECK; GUNTER MALLE

441

Group Creativity and Technology.  

ERIC Educational Resources Information Center

This paper first reviews the theory of group creativity and then examines characteristics of electronic brainstorming that make it more effective than verbal brainstorming. The success of electronic brainstorming suggests it might be the key to overcoming the space and time constraints commonly faced by a creativity group. (Author/DB)

Siau, Keng L.

1995-01-01

442

21 CFR 868.2500 - Cutaneous oxygen (PcO 2) monitor.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 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...

2013-04-01

443

Ageing of PC\\/PBT blend: Mechanical properties and recycling possibility  

Microsoft Academic Search

A polycarbonate (PC) and poly (butylene terephthalate) (PBT) blend is extensively used for moulded automobile parts. PC is tough and stable to 300°C and PBT has relatively good solvent resistance. An alloy formed with those two polymers produces a material with good chemical resistance as well as good heat and impact resistance. In this work, a PC\\/PBT blend, with and

Elisabete Maria Saraiva Sanchez

2007-01-01

444

User's guide for an interactive fault tree editor, PC-CREFTS.  

National Technical Information Service (NTIS)

To support the core damage frequency evaluation in probabilistic safety assessment (PSA) for nuclear power plants, a personal computer (PC) based level-1 program package named PC-REFT (PC-Based Reliability Analysis with Event Tree and Fault Tree Technique...

N. Watanabe K. Tamura

1993-01-01

445

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

446

WriteOn1.0: a tablet PC-based tool for effective classroom instruction  

Microsoft Academic Search

A Tablet PC combines all the features of a regular laptop computer with a digitizing screen that interacts with a complementary electronic pen stylus. The ability to annotate on a lecture presentation using the pen stylus of the Tablet PC has attracted the attention of academics to use them as a potential tool for effective classroom instruction. Tablet PC based

Samantha Chandrasekar; Joseph G. Tront; Jane C. Prey

2009-01-01

447

The load capacity of PC\\/ABS spur gears and investigation of gear damage  

Microsoft Academic Search

Recently, Polyamide 66 and Teflon as plastic materials are widely used at the manufacturing of gear mechanism. The using of PC\\/ ABC materials provides many advantages due to fire, air and ultraviolet light durability and low moisture holding properties. In this study, the usability of PC\\/ABS composite plastic materials as spur gear was investigated. PC\\/ABS gears were tested by applying

Rifat Yakut; Mehmet Turan Demirci

448

Recent Developments on PC+PLC based Control Systems for Beer Brewery Process Automation Applications  

Microsoft Academic Search

Manufacturers are continuing to do their best efforts for cost effective production systems in order to contribute consumers' requirement. Such environment carries plant operations using quite flexible control systems such as PC (personal computer) - PLC (programmable logic controller) combination control systems called PC+PLC based control system. However, almost PC+PLC based control systems has been applied for small to medium

M. Ogawa; Y. Henmi

2006-01-01

449

Collaborative Spaces  

ERIC Educational Resources Information Center

|When architects discuss the educational facilities of the next century and beyond, the conversation turns to collaborative spaces. They envision flexible and fluid spaces that will encourage creative and critical thinking, and free students to communicate clearly about the task at hand. While these are admirable ideals, there are some fundamental…

Lippman, Peter C.

2013-01-01

450

Space Handbook.  

National Technical Information Service (NTIS)

The responsibilities of the Air Force in space include a large and growing number of functions that contribute to the defense of the United States. Space operations are important elements of a credible deterrent to armed conflict. In the near-term, should...

C. D. Cochran D. M. Gorman J. D. Dumoulin

1985-01-01

451

Space Telescope.  

ERIC Educational Resources Information Center

This pamphlet describes the Space Telescope, an unmanned multi-purpose telescope observatory planned for launch into orbit by the Space Shuttle in the 1980s. The unique capabilities of this telescope are detailed, the major elements of the telescope are described, and its proposed mission operations are outlined. (CS)

National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

452

Space Debris  

NSDL National Science Digital Library

This Wikipedia article provides information about space debris, the objects in orbit around Earth left over from earlier space missions. The article introduces the history of orbital debris production as well as the growing concern about collisions between this debris and functional satellites. Links provide further information.

2008-02-26

453

Space Review.  

National Technical Information Service (NTIS)

Human space flight in the US and other space-faring countries is faced with a twin challenge that is likely to persist for many years: flat or declining budgets along with an expectation of continuing, significant achievements. A partial solution may invo...

D. Lester H. Thronson S. Hatfield

2011-01-01

454

Space flight  

NASA Astrophysics Data System (ADS)

Wayne Littles will take over the job of Associate Administrator for Space Flight at NASA from Maj.Gen. Jeremiah W. Pearson, who has resigned from the post. Littles, now NASA's Chief Engineer, was formerly deputy director of the Marshall Space Flight Center in Huntsville, Ala.

455

Biological processing of the cocaine and amphetamine-regulated transcript precursors by prohormone convertases, PC2 and PC1/3.  

PubMed

Cocaine and amphetamine-regulated transcript (CART), a neuroendocrine peptide influencing reward, feeding/appetite, and stress responses is derived from two peptide precursors of 129 and 116 amino acid (aa) residues that arise via alternative splicing from a single Cart gene in rats and mice. The signal peptide constitutes the first 27 aa resulting in pro-CART molecules of either 102 or 89 aa. In the present study, we have shown that pro-CART is a substrate for the neuroendocrine subtilisin/kexin-like prohormone convertases, PC2 (SPC2) and PC1/3 (SPC3). By using different neuroendocrine cell lines, with or without endogenous expression of either PC2 or PC1/3 or both enzymes, we have demonstrated through transient transfection studies that long pro-CART gives rise to an intermediate peptide, residues 33-102, and the two major bioactive CART forms, residues 55-102 (I) and 62-102 (II), respectively. Likewise, short pro-CART also generates three peptides, an intermediate, residues 10-89, and the two identical bioactive CART forms. We have confirmed the identities of the bioactive and intermediate CART molecules by microsequencing and/or high performance liquid chromatography and mass spectrometry. We have shown that PC2 is more efficient in generating bioactive CART I compared with PC1/3, whereas the production of the smaller bioactive CART II is exclusively carried out by PC2. PC1/3 is predominantly responsible for generating the intermediate CART fragments, 33-102 and 10-89, from long and short pro-CART, respectively. To compare in vitro and in vivo processing of pro-CART, we have examined its processing in PC2, 7B2, and PC1/3 knock-out mouse hypothalamic extracts and demonstrated that, as in vitro, PC2 is more potent than PC1/3 in generating bioactive CART I whereas bioactive CART II is solely generated by PC2. Also, in vivo, we have shown that PC1/3 is predominantly active in liberating the two intermediate CART fragments, 33-102 and 10-89. These findings confirm the key roles of PC2 and PC1/3 acting together or separately to carry out CART processing in selected sites in vivo. PMID:12584191

Dey, Arunangsu; Xhu, Xiaorong; Carroll, Raymond; Turck, Christopher W; Stein, Jeffrey; Steiner, Donald F

2003-02-12

456

Space Weather  

NASA Astrophysics Data System (ADS)

This volume provides a comprehensive overview of our current observational knowledge, theoretical understanding, and numerical capability with regard to the phenomena known as space weather. Space weather refers to conditions on the Sun and in the solar wind, magnetosphere, ionosphere, and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems, and can endanger human life or health. The rapid advance in these technologies has provided us with unprecedented capability and convenience, and we have come to rely on them more and more. Technology has reduced society's risk to many kinds of natural disasters, but through its own vulnerability, it has actually increased society's risk to space weather. Adverse conditions in the space environment can cause disruption of satellite operations, communications, navigation, and electric power distribution grids, leading to a variety of socioeconomic losses.

Song, Paul; Singer, Howard J.; Siscoe, George L.

457

Space Weather  

NASA Astrophysics Data System (ADS)

Following James Van Allen's discovery of Earth's radiation belts (1958), it was immediately recognized that the space environment would be hostile to the communications satellites that had been envision by Arthur Clark (1945) and John Pierce (1955). Van Allen's discovery set off a burst of "space weather" research and engineering that continues to today, paralleling "space weather" research that had, prior to 1958, been directed toward understanding environment effects on cable and early wireless communications, electric power distribution, and pipelines. Van Allen's discovery also meant that the flight of humans above the sensible atmosphere would be fraught with more peril than mere weightlessness. This Van Allen lecture will discuss the space weather considerations that arose from Van Allen's discovery as well as space weather effects that occur from numerous other physical processes in the complex sun-heliosphere-magnetosphere environmental system.

Lanzerotti, L. J.

2005-05-01

458

Serum stimulates sodium uptake by rat papillary collecting duct cells (RtPC) in culture  

SciTech Connect

RtPC play an important role in the regulation of sodium excretion by the kidney. RtPC were obtained from Sprague-Dawley rats and cultured on filter-bottom cups in a serum-free medium for 5 days. For the next 24 hr the cells were grown either in S- or in Dulbecco's/F12 supplemented with 10% serum (S+). In 12 primary cultures, the transepithelial resistance (Rt) was significantly higher in S+ (118 +/- 12 ohm cm/sup 2/, n = 45) than in S- (74 +/- 13, n = 41). Short-circuit current was not different between the groups. Na uptake was measured from the apical solution after 60 sec exposure to isotope in a low Na (27 mM) Ringer (same cells as Rt). Despite