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Sample records for abcd ring structure

  1. Synthesis of the Tetracyclic ABCD Ring Domain of Calyciphylline A-Type Alkaloids via Reductive Radical Cyclizations.

    Science.gov (United States)

    Coussanes, Guilhem; Bonjoch, Josep

    2017-02-17

    A tetracyclic compound with the ABCD ring framework of calyciphylline A-type alkaloids was synthesized from a cis-3a-methyloctahydroindole triggered by a 5-endo radical cyclization. The synthesis required two additional ring-forming steps: the construction of a seven-membered ring by aldol cyclization and the azabicyclic fragment by a radical ring closure of a trichloroacetamide-tethered enol acetate followed by a diastereoselective α-methylation of the lactam group.

  2. Matrimonial ring structures

    OpenAIRE

    Hamberger, Klaus; Houseman, Michael; Daillant, Isabelle; White, Douglas R.; Barry, Laurent

    2006-01-01

    The paper deals with matrimonial rings, a particular kind of cycles in kinship networks which result when spouses are linked to each other by ties of consanguinity or affinity. By taking a network-analytic perspective, the paper endeavours to put this classical issue of structural kinship theory on a general basis, such as to allow conclusions which go beyond isolated discussions of particular ring types (like "cross-cousin marriage", "sister exchange", and so forth). The paper provides a def...

  3. Stereochemical Complexity in Oxocarbenium-Ion-Initiated Cascade Annulations for the Synthesis of the ABCD Core of Mattogrossine.

    Science.gov (United States)

    Kong, Aidi; Andreansky, Eric S; Blakey, Simon B

    2017-04-21

    Mattogrossine is an indole alkaloid isolated from Strychnos mattogrossensis that contains an unusual tetrahydrofuran ring with a concomitant hemiacetal in its structure. While tetrahydrofuran intermediates have been used in the synthesis of other strychnos alkaloids, no investigations have been performed into the synthesis of alkaloids containing this structure. We have developed an oxocarbenium-ion-initiated cascade annulation that provides us access to the ABCD ring structure of mattogrossine.

  4. The Fine Structure of Herman Rings

    DEFF Research Database (Denmark)

    Fagella, Nuria; Henriksen, Christian

    2017-01-01

    We study the geometric structure of the boundary of Herman rings in a model family of Blaschke products of degree 3 (up to quasiconformal deformation). Shishikura’s quasiconformal surgery relates the Herman ring to the Siegel disk of a quadratic polynomial. By studying the regularity properties...... of the maps involved, we transfer McMullen’s results on the fine local geometry of Siegel disks to the Herman ring setting....

  5. Irregular Wavelike Structure in Saturn's Rings

    Science.gov (United States)

    Pollard, Benjamin J.

    2005-01-01

    We have searched Saturn's A, B, and C rings for irregular wavelike structure using Voyager Photopolarimeter (PPS), Ultraviolet Spectrometer (UVS), and Radio Science (RSS) occultation datasets, as well as ring reflectivity profiles derived from Voyager images. A maximum entropy technique for conducting spectral analysis was used to estimate wave frequency power in relation to radial location for each dataset. Using this method we have found irregular structure in the PPS and UVS inner B Ring occultation datasets previously identified in Voyager imaging data. Both finer structure, with a wavelength of around 20 km, and large structure with wavelengths of 200 to 1000 km, are visible in the occultation data and appear similar to that seen in the imaging data. After removing ringlets from the C-Ring data, we have identified what appears to be a 1000-km wave sustained throughout the ring. The large dominant wavelength appears in all datasets; however, tests are currently being conducted in an attempt to verify its existence. Irregular structure with a wavelength of approximately 20 km has been observed in the C Ring reflectivity profiles, but not within the occultation datasets. This leads us to doubt it is caused by ring surface mass density fluctuations detectable by the occultation experiments.

  6. TEST ON ABCD CHIPS

    CERN Document Server

    Ferrère, D; Zsenei, A; Kaplon, J; Lacasta, C; Dabrowski, W; Kudlaty, J; Wolter, M; Azman, S

    1998-01-01

    The ABCD chip is one of the two technological options for the binary readout architecture under development for the Silicon Tracker (SCT) in ATLAS. The chip is realised in the DMILL technology (a 0.8 mum BICMOS trench isolation process). This note reports on the first results obtained at CERN on the p-type ABCD chips of the first batch delivered by TEMIC in February 1998.

  7. Structured LDPC Codes over Integer Residue Rings

    Directory of Open Access Journals (Sweden)

    Marc A. Armand

    2008-07-01

    Full Text Available This paper presents a new class of low-density parity-check (LDPC codes over ℤ2a represented by regular, structured Tanner graphs. These graphs are constructed using Latin squares defined over a multiplicative group of a Galois ring, rather than a finite field. Our approach yields codes for a wide range of code rates and more importantly, codes whose minimum pseudocodeword weights equal their minimum Hamming distances. Simulation studies show that these structured codes, when transmitted using matched signal sets over an additive-white-Gaussian-noise channel, can outperform their random counterparts of similar length and rate.

  8. Structured LDPC Codes over Integer Residue Rings

    Directory of Open Access Journals (Sweden)

    Mo Elisa

    2008-01-01

    Full Text Available Abstract This paper presents a new class of low-density parity-check (LDPC codes over represented by regular, structured Tanner graphs. These graphs are constructed using Latin squares defined over a multiplicative group of a Galois ring, rather than a finite field. Our approach yields codes for a wide range of code rates and more importantly, codes whose minimum pseudocodeword weights equal their minimum Hamming distances. Simulation studies show that these structured codes, when transmitted using matched signal sets over an additive-white-Gaussian-noise channel, can outperform their random counterparts of similar length and rate.

  9. Comparing and Selecting Generalized Double Ring Network Structures

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Knudsen, Thomas Phillip; Madsen, Ole Brun

    2004-01-01

    N2R(p;q) network structures were introduced recently as a generalization of double rings, and they were shown to be superior compared to double rings in terms of average distance and diameter. For a given number of nodes, there is only one double ring, but often more different N2R(p;q) structures...

  10. Magnetic thin film Fe ring structures and devices

    Science.gov (United States)

    Hou, Yufeng

    Magnetic thin film ring structures show distinct magnetic states and highly reproducible switching behavior, which makes them candidates for multiple magnetoelectronic and sensing devices. The magnetic states and switching behaviors of thin film ring structures are closely related to their physical properties such as the lateral size, thickness, width and the material anisotropy. In order to systematically study the magnetic properties of thin film ring structures, we use different techniques such as photolithography and electron-beam lithography to fabricate magnetic thin film Fe ring structures with different outer diameter (Dout), thickness (tFe) and inner-to-outer diameter ratio ( Din/Dout). The magnetization reversal processes of these Fe ring structures are studied using magneto-optical Kerr effect and magnetic force microscopy. To explain the magnetic behavior of the Fe ring structures observed in experiments, we use LLG micromagnetic simulation to model the domain configuration of the Fe ring during switching. The evolution of magnetic reversal behaviors in Fe ring structures is also explained by calculating the energy densities of vortex state, single-domain state and axial state with micromagnetic simulator. To control the magnetic switching behavior of the Fe ring structures, exchange bias interfacial coupling is introduced into the ring structure by growing a bilayer of IrMn/Fe in the ring structure. By studying the angular dependence of the hysteresis loop shift, we find that exchange bias induces a magnetic unidirectional anisotropy and a collinear magnetic uniaxial anisotropy in the ring structure. Exchange bias induced magnetic anisotropies cause anisotropic magnetic reversal modes in IrMn/Fe (10 nm) ring and a higher one-step to two-step transitional thickness in IrMn/Fe (x nm) ring structures. After study the magnetic properties of the Fe rings and exchange biased IrMn/Fe rings, we incorporate them into one ring shape magnetic tunneling junction

  11. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring

    OpenAIRE

    Chuanjun Han; Han Zhang; Jie Zhang

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficie...

  12. Ring and Volcano Structures Formed by a Metal Dipyrromethene Complex

    Energy Technology Data Exchange (ETDEWEB)

    Son, Seung Bae; Hahn, Jae Ryang [Chonbuk National Univ., Jeonju (Korea, Republic of); Miao, Qing; Shin, Jiyoung; Dolphin, David [Univ. of British Columbia, Columbia (Canada)

    2014-06-15

    Dichloromethane liquid droplets containing a cobalt dipyrromethene trimer deposited on a graphite surface were found to form coffee ring, toroid ring, or volcano dot structures due to the redistribution of the solute during solvent evaporation. The shapes and size distributions of the ring structures depended on the drying temperature. The shape differences were attributed to the fact that the solvent evaporation rate controlled the self-assembly process that yielded the coffee stain and pinhole structures.

  13. Large and small-scale structures in Saturn's rings

    Science.gov (United States)

    Albers, N.; Rehnberg, M. E.; Brown, Z. L.; Sremcevic, M.; Esposito, L. W.

    2017-09-01

    Observations made by the Cassini spacecraft have revealed both large and small scale structures in Saturn's rings in unprecedented detail. Analysis of high-resolution measurements by the Cassini Ultraviolet Spectrograph (UVIS) High Speed Photometer (HSP) and the Imaging Science Subsystem (ISS) show an abundance of intrinsic small-scale structures (or clumping) seen across the entire ring system. These include self-gravity wakes (50-100m), sub-km structure at the A and B ring edges, and "straw"/"ropy" structures (1-3km).

  14. Dynamics and Structure of Planetary Rings

    Science.gov (United States)

    French, Richard G.

    2002-01-01

    We developed a novel technique to determine the macroscopic particle size distribution of Saturn's rings by exploiting diffraction effects during stellar occultations. This was a major undertaking, and resulted in two publications now in press. In the latter paper, we derived power-law particle size distributions for each of Saturn's main ring regions, using observations of the 3 July 1989 stellar occultation of 28 Sgr from Palomar, McDonald, and Lick Observatories. We used the Voyager PPS delta Sco optical depth profile to estimate and then remove the directly transmitted signal from the 28 Sgr observations, leaving high SNR scattered light profiles at wavelengths of 3.9, 2.1, and 0.9 micrometers. The angular distribution of this diffracted signal depends on the ring particle size distribution: the sharpness of the forward lobe is set by the largest particles, while the overall breadth and amplitude of the scattered signal reflects the abundance of smaller, cm-sized particles. We developed both a simple one-dimensional scattering model and a more realistic 2-D model. We assumed for simplicity a single power law particle size distribution for each major ring region, and determined the index q and lower and upper size cutoffs amin and amax that provide the best match to all three data sets in each region. Our results in the A and C Rings are fairly consistent with values of q and amax derived from Voyager radio occultation (RSS) measurements. We extended their results by determining lower limits to the particle size distributions and by probing the B Ring. This technique is applicable to imaging observations of the rings during the Cassini mission.

  15. Dynamics and Structure of Planetary Rings

    Science.gov (United States)

    French, Richard G.

    2002-01-01

    We developed a novel technique to determine the macroscopic particle size distribution of Saturn's rings by exploiting diffraction effects during stellar occultations. This was a major undertaking, and resulted in two publications now in press. In the latter paper, we derived power-law particle size distributions for each of Saturn's main ring regions, using observations of the 3 July 1989 stellar occultation of 28 Sgr from Palomar, McDonald, and Lick Observatories. We used the Voyager PPS delta Sco optical depth profile to estimate and then remove the directly transmitted signal from the 28 Sgr observations, leaving high SNR scattered light profiles at wavelengths of 3.9, 2.1, and 0.9 micrometers. The angular distribution of this diffracted signal depends on the ring particle size distribution: the sharpness of the forward lobe is set by the largest particles, while the overall breadth and amplitude of the scattered signal reflects the abundance of smaller, cm-sized particles. We developed both a simple one-dimensional scattering model and a more realistic 2-D model. We assumed for simplicity a single power law particle size distribution for each major ring region, and determined the index q and lower and upper size cutoffs a(sub min) and a(sub max) that provide the best match to all three data sets in each region. Our results in the A and C Rings are fairly consistent with values of q and a(sub max) derived from Voyager radio occultation (RSS) measurements. We extended their results by determining lower limits to the particle size distributions and by probing the B Ring. This technique is applicable to imaging observations of the rings during the Cassini mission.

  16. Sharp Edges in Saturn's Rings: Radial Structure and Longitudinal Variability

    Science.gov (United States)

    Colwell, Joshua E.; Jerousek, R. G.; Esposito, L. W.

    2010-10-01

    The Cassini Ultraviolet Imaging Spectrograph has observed more than 100 occultations of stars by Saturn's rings with a typical ring plane radial resolution of preventing a fit from our smooth model. We find that the radial scale, characterized by a sigmoid function, over which the ring optical depth declines is typically 10-20 m. We are unable to place a tight constraint on the vertical thickness of the ring, however, because the light curve is dominated by the scale of the radial variation. We find large variability in the structure of the edges with no clear correlation to known possible perturbers in the system.

  17. Autoridade Brasileira de Controle de Dopagem (ABCD).

    Science.gov (United States)

    Santos, Azenildo M; Bahrke, Michael S

    2014-11-01

    The creation of the ABCD and the inclusion for the first time of a provision of financial resources in the Government's General Budget Forecast, demonstrates the degree of Brazil's commitment in the fight against doping. This as we seek to know and evaluate these models of excellence to help to structure and develop our own doping control operations, always taking into account the Brazilian reality.

  18. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring.

    Science.gov (United States)

    Han, Chuanjun; Zhang, Han; Zhang, Jie

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal.

  19. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring

    Directory of Open Access Journals (Sweden)

    Chuanjun Han

    2015-01-01

    Full Text Available In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal.

  20. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring

    Science.gov (United States)

    Han, Chuanjun

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal. PMID:27019582

  1. Delay-insensitive Multi-ring Structures

    DEFF Research Database (Denmark)

    Sparsø, Jens; Staunstrup, Jørgen

    1993-01-01

    This paper describes a set of simple design and performance analysis techniques that have been successfully used to design a number of non-trivial delay-insensitive circuits. Examples are building blocks for digital filters and a vector multiplier using a serial-parallel multiply and accumulate...... algorithm. The vector multiplier has been laid out, submitted for fabrication, and successfully tested. This design is described in detail to illustrate the design and the performance analysis techniques. The design technique is based on a data flow approach using pipelines and rings that are composed...

  2. Analysis of regular structures third degree based on chordal rings

    DEFF Research Database (Denmark)

    Bujnowski, Slawomir; Dubalski, Bozydar; Pedersen, Jens Myrup

    2009-01-01

    . In the first part of paper, formulas for the basic parameters diameter and average path length were derived using optimal/ideal graphs, and used for indicating transmission properties of the structures. These analytical results were confirmed by comparison to a large number of computations on real graphs.  In......  This paper presents an analysis of modified chordal rings third degree (CR3m) and modified double ring structure (N2Rm), which can be used as models of real networks. The proposed solutions are novel and different from the ones currently used since they have two chords of different lengths...

  3. Lattice-valued convergence ring and its uniform convergence structure

    African Journals Online (AJOL)

    Considering L a frame, we introduce the notion of stratified L-neighborhood topological ring, produce some characterization theorems including its Luniformizability. With the help of the notions of stratified convergence structures attributed to Gunther J¨ager [10], we introduce and study various subcategories of stratified ...

  4. The puzzling structure in Saturn's outer B ring

    Science.gov (United States)

    Nicholson, Philip D.; Hedman, Matt; Buckingham, Rikley

    2017-06-01

    As first noted in Voyager images, the outer edge of Saturn's B ring is strongly perturbed by the 2:1 inner Lindblad resonance with Mimas (Porco \\etal\\ 1984). Cassini imaging and occultation data have revealed a more complex situation, where the expected resonantly-forced m=2 perturbation with an amplitude of 33~km is accompanied by freemodes with m=1, 2, 3, 4 and 5 (Spitale & Porco 2010, Nicholson \\etal\\ 2014a). To date, however, the structure immediately interior to the ring edge has not been examined carefully. We have compared optical depth profiles of the outer 1000~km of the B ring, using a large set of stellar occultations carried out since 2005 by the Cassini VIMS instrument. A search for wavelike structure, using a code written to search for hidden density waves (Hedman \\& Nicholson 2016), reveals a significant signature at a radius of ~117,150 km with a radial wavelength of ~110 km. This appears to be a trailing spiral with m=1 and a pattern speed equal to the local apsidal precession rate, $\\dpi\\simeq5.12\\dd$. Further searches for organized large-scale structure have revealed none with m=2 (as might have been expected), but several additional regions with significant m=1 variations and pattern speeds close to the local value of $\\dpi$. At present, it is unclear if these represent propagating spirals, standing waves, or perhaps features more akin to the eccentric ringlets often seen within gaps in the C ring and Cassini Division (Nicholson \\etal\\ 2014b, French \\etal\\ 2016). Comparisons of sets of profiles from 2008/9, 2012-14 and 2016 seem to show that these structures are changing over time.

  5. A UNIMARC Bibliographic Format Database for ABCD

    Science.gov (United States)

    Megnigbeto, Eustache

    2012-01-01

    Purpose: ABCD is a web-based open and free software suite for library management derived from the UNESCO CDS/ISIS software technology. The first version was launched officially in December 2009 with a MARC 21 bibliographic format database. This paper aims to detail the building of the UNIMARC bibliographic format database for ABCD.…

  6. Graphical linking of MO multicenter bond index and VB structures. II-5-c rings and 6-c heterocyclic rings

    CERN Document Server

    Bollini, C G; Giambiagi, M

    2001-01-01

    Through the graphical method proposed it is possible to set a link between an MO multicenter bond index and VB structures. The value of the index depends on the order of the atoms involved if they are more than three. For 5-c rings three basic structures are required; the eventually different values are 12. Unlike the 6-c case it may happen that different pairs of basic structures are used to build the same polygon. For the 6-c rings including heteroatoms the original degeneracy of benzene splits leading eventually to 60 different I sub r sub i sub n sub g values.

  7. Microwave Spectra, Structure, and Ring-Puckering Vibration of Octafluorocyclopentene.

    Science.gov (United States)

    Long, B E; Arsenault, Eric A; Obenchain, Daniel A; Choi, Yoon Jeong; Ocola, Esther J; Laane, Jaan; Pringle, Wallace C; Cooke, S A

    2016-11-03

    The rotational spectra of octafluorocyclopentene (C5F8) has been measured for the first time using pulsed jet Fourier transform microwave spectroscopy in a frequency range of 6 to 16 GHz. As in the molecule cyclopentene, the carbon ring is nonplanar, and inversion through the plane results in an inversion pair of ground state vibrational energy levels with an inversion splitting of 18.4 MHz. This large amplitude motion leads to the vibration-rotation coupling of energy levels. The symmetric double minimum ring-puckering potential function was calculated, resulting in a barrier of 222 cm-1. The rotational constants A0 = 962.9590(1) MHz, B0 = 885.1643(4) MHz, C0 = 616.9523(4) MHz, A1 = 962.9590(1) MHz, B1 = 885.1643(4) MHz, C1 = 616.9528(4) MHz, and two centrifugal distortion constants for each state were determined for the parent species and all 13C isotopologues. A mixed coordinate molecular structure was determined from a least-squares fit of the ground state rotational constants of the parent and each 13C isotopologue combined with the equilibrium bond lengths and angles from quantum chemical calculations.

  8. On Embedding N2R Structures in Optical Fiber OMS-SP Ring

    DEFF Research Database (Denmark)

    Riaz, Muhammad Tahir; Pedersen, Jens Myrup; Nielsen, Rasmus Hjorth

    2006-01-01

    The objective of this paper is to propose methods for embedding N2R structures in optical fiber OMS-SP rings. The OMS-SP ring supports full mesh structure and restoration on the optical level. The N2R structures have been proven to be superior to other degree 3 network structures. Two main mappin...

  9. Abcd2 is a strong modifier of the metabolic impairments in peritoneal macrophages of ABCD1-deficient mice.

    Directory of Open Access Journals (Sweden)

    Zahid Muneer

    Full Text Available The inherited peroxisomal disorder X-linked adrenoleukodystrophy (X-ALD, associated with neurodegeneration and inflammatory cerebral demyelination, is caused by mutations in the ABCD1 gene encoding the peroxisomal ATP-binding cassette (ABC transporter ABCD1 (ALDP. ABCD1 transports CoA-esters of very long-chain fatty acids (VLCFA into peroxisomes for degradation by β-oxidation; thus, ABCD1 deficiency results in VLCFA accumulation. The closest homologue, ABCD2 (ALDRP, when overexpressed, compensates for ABCD1 deficiency in X-ALD fibroblasts and in Abcd1-deficient mice. Microglia/macrophages have emerged as important players in the progression of neuroinflammation. Human monocytes, lacking significant expression of ABCD2, display severely impaired VLCFA metabolism in X-ALD. Here, we used thioglycollate-elicited primary mouse peritoneal macrophages (MPMΦ from Abcd1 and Abcd2 single- and double-deficient mice to establish how these mutations affect VLCFA metabolism. By quantitative RT-PCR, Abcd2 mRNA was about half as abundant as Abcd1 mRNA in wild-type and similarly abundant in Abcd1-deficient MPMΦ. VLCFA (C26∶0 accumulated about twofold in Abcd1-deficient MPMΦ compared with wild-type controls, as measured by gas chromatography-mass spectrometry. In Abcd2-deficient macrophages VLCFA levels were normal. However, upon Abcd1/Abcd2 double-deficiency, VLCFA accumulation was markedly increased (sixfold compared with Abcd1-deficient MPMΦ. Elovl1 mRNA, encoding the rate-limiting enzyme for elongation of VLCFA, was equally abundant across all genotypes. Peroxisomal β-oxidation of C26∶0 amounted to 62% of wild-type activity in Abcd1-deficient MPMΦ and was significantly more impaired (29% residual activity upon Abcd1/Abcd2 double-deficiency. Single Abcd2 deficiency did not significantly compromise β-oxidation of C26∶0. Thus, the striking accumulation of VLCFA in double-deficient MPMΦ compared with single Abcd1 deficiency was due to the loss of

  10. Different structures caused by embedded moonlets in a planetary ring: an application to the F ring of Saturn

    Science.gov (United States)

    Silva, P. A.; Giuliatti Winter, S. M.

    Embedded moonlets are claimed to be responsible for a variety of structures found in narrow planetary rings. The strange features present in the F ring such as clumps and kinks can be related to these hypothetical moonlets. In an attempt to understand the behavior of the ring particles under the effects of these moonlets, numerical simulations have been carried out for a system composed of two and three moonlets. In these simulations the moonlets, with equal masses, were located in equilibrium positions found by Salo and Yoder (A & A, 205, 1988). The results of these simulations have shown that depending on the eccentricity of the particles and the moonlets the ring can present azimuthal and radial variations. Although these variations can explain some clumps, the simulations also show that most of the features are temporary ones. For the system formed by the F ring-Prometheus-Pandora was verified that it is considerably sensible to the initial conditions. Complementary to this study, the equilibrium positions for the particles and moonlets (with unequal masses) were obtained. These equilibrium positions can help to locate embedded moonlets in narrow planetary rings.

  11. Correlation between ABCD, ABCD2 scores and craniocervical artery stenosis in patients with transient ischemic attack.

    Science.gov (United States)

    Sun, Wen; Dai, Jiafei; Xiong, Yunyun; Huang, Zhixin; Li, Yongkun; Liu, Wenhua; Zhu, Wusheng; Xu, Gelin; Liu, Xinfeng

    2013-01-01

    Craniocervical artery stenosis is an important etiology for transient ischemic attack (TIA). We hypothesized ABCD and ABCD2 scores can predict craniocervical artery stenosis in patients with TIA. ABCD and ABCD2 scores were calculated in a total of 479 consecutive first-ever TIA patients in Nanjing Stroke Registry Program and compared with angiographic imaging derived from MRI or invasive catheter-based angiography. Overall craniocervical artery (O-CA) stenosis was found in 197 (41.1%) patients. Extracranial craniocervical artery (E-CA) and intracranial craniocervical artery (I-CA) stenosis was found in 101 (21.1%) and 110 (23%) cases, respectively. ABCD and ABCD2 scores with similar accuracy for O-CA (AUCABCD 0.71, AUCABCD2 0.70), E-CA (AUCABCD 0.72, AUCABCD2 0.72) and I-CA stenosis (AUCABCD 0.62, AUCABCD2 0.62) were both independent predictors for various categories of artery stenosis after being adjusted for non-ABCD2 parameters. The cut-off points were equally 4 in both predicting rules. For ABCD, sensitivity was 57.4, 65.3 and 52.7% and specificity 77.0, 70.4 and 67.5% for O-CA/E-CA/I-CA, respectively. For ABCD2, sensitivity was 61.9, 69.3 and 58.2% and specificity 72.3, 65.6 and 63.1%. In patients with TIA, despite an association between ABCD and ABCD2 scores and underlying craniocervical artery stenosis, the clinical utility was limited by unsatisfactory sensitivity and specificity. Copyright © 2013 S. Karger AG, Basel.

  12. [A high sensitivity micro-ring humidity sensor based on U-shaped waveguide coupled single micro-ring structure].

    Science.gov (United States)

    Li, Zhi-quan; Wang, Lu-na; Li, Xin; Zhang, Xin

    2015-02-01

    The paper proposes a novel high sensitivity humidity sensor based on a U-shaped waveguide-coupled single micro-ring, Polyimide is used as the wet material, the refractive index of humidity-sensing part changes as relative humidity changes, thus leading to a obvious peak drift. The transfer function of the structure is derived basing on transfer matrix method and the paper mainly discusses the influence on the output spectrum with different humidity-sensing parts. Through the theoretical simulation of Matlab, the whole structure of U-shaped waveguide coupled single micro-ring is proved to be the best humidity-sensing part. The free spectral range (FSR) will be doubled compared to the traditional single micro ring structure while the length between the two coupling points of the U-shaped waveguide is an integer multiple of circumference of the micro-ring. When the relative humidity of external environment changes from 10% RH to 100% RH, the output spectrum appears a obvious drift from 0.027 to 0.191 microm and the sensitivity reaches up to 0.0018 microm/% RH. Compared to FBG humidity sensor with high sensitivity, the sensitivity in this article is increased by 10 to 100 times, achieving a high sensitivity in the sense of humidity when the wide range of filter frequency selection is taken into account.

  13. Self-assembly of vertically aligned quantum ring-dot structure by Multiple Droplet Epitaxy

    Science.gov (United States)

    Elborg, Martin; Noda, Takeshi; Mano, Takaaki; Kuroda, Takashi; Yao, Yuanzhao; Sakuma, Yoshiki; Sakoda, Kazuaki

    2017-11-01

    We successfully grow vertically aligned quantum ring-dot structures by Multiple Droplet Epitaxy technique. The growth is achieved by depositing GaAs quantum rings in a first droplet epitaxy process which are subsequently covered by a thin AlGaAs barrier. In a second droplet epitaxy process, Ga droplets preferentially position in the center indentation of the ring as well as attached to the edge of the ring in [ 1 1 bar 0 ] direction. By designing the ring geometry, full selectivity for the center position of the ring is achieved where we crystallize the droplets into quantum dots. The geometry of the ring and dot as well as barrier layer can be controlled in separate growth steps. This technique offers great potential for creating complex quantum molecules for novel quantum information technologies.

  14. Structure, Vibrational Spectra and Ring Puckering Barrier of Cyclobutane

    Energy Technology Data Exchange (ETDEWEB)

    Xantheas, Sotiris S.; Blake, Thomas A.

    2006-09-02

    We present the results of high level ab initio calculations on the structure and puckering barrier of cyclobutane in an effort to establish the minimum theoretical requirements needed for their accurate description. Our best computed value for the puckering angle is 29.68o. Furthermore we found that accurate estimates for the barrier between the minimum (D2d) and transition state (D4h) configurations require both higher levels of electron correlation [MP4, CCSD(T)] and basis sets of quadruple-z quality or larger. By performing CCSD(T) calculations with basis sets as large as cc-pV5Z we obtained a complete basis set (CBS) estimate of 498 cm-1 for the puckering barrier. Our estimate for the barrier is within 10 cm-1 to the value proposed originally, but it lies ~50 cm-1 higher than the one obtained more recently, therefore revisiting the analysis of the experimental data might be warranted. The results of the current study can serve as a guide for calculations on the substituted four member ring compounds. To this end we present a method for estimating the barrier height at higher levels of electron correlation [MP4, CCSD(T)] from the MP2 results.

  15. ABCD1 deletion-induced mitochondrial dysfunction is corrected by SAHA: implication for adrenoleukodystrophy.

    Science.gov (United States)

    Baarine, Mauhamad; Beeson, Craig; Singh, Avtar; Singh, Inderjit

    2015-05-01

    X-linked Adrenoleukodystrophy (X-ALD), an inherited peroxisomal metabolic neurodegenerative disorder, is caused by mutations/deletions in the ATP-binding cassette transporter (ABCD1) gene encoding peroxisomal ABC transporter adrenoleukodystrophy protein (ALDP). Metabolic dysfunction in X-ALD is characterized by the accumulation of very long chain fatty acids ≥ C22:0) in the tissues and plasma of patients. Here, we investigated the mitochondrial status following deletion of ABCD1 in B12 oligodendrocytes and U87 astrocytes. This study provides evidence that silencing of peroxisomal protein ABCD1 produces structural and functional perturbations in mitochondria. Activities of electron transport chain-related enzymes and of citric acid cycle (TCA cycle) were reduced; mitochondrial redox status was dysregulated and the mitochondrial membrane potential was disrupted following ABCD1 silencing. A greater reduction in ATP levels and citrate synthase activities was observed in oligodendrocytes as compared to astrocytes. Furthermore, most of the mitochondrial perturbations induced by ABCD1 silencing were corrected by treating cells with suberoylanilide hydroxamic acid, an Histone deacetylase inhibitor. These observations indicate a novel relationship between peroxisomes and mitochondria in cellular homeostasis and the importance of intact peroxisomes in relation to mitochondrial integrity and function in the cell types that participate in the pathobiology of X-ALD. These observations suggest suberoylanilide hydroxamic acid as a potential therapy for X-ALD. Schematic description of the effects of loss of peroxisomal ATP-binding cassette transporter D1 (ABCD1) gene on cellular Redox and mitochondrial activities and their correction by suberoylanilide hydroxamic acid (SAHA) treatment. Pathogenomic accumulation of very long chain fatty acids (VLCFA) as a result of loss of ABCD1 leads to dysfunctions of mitochondrial biogenesis and its activities. Treatment with SAHA corrects

  16. Organizing some very tenuous things: Resonant structures in Saturn's faint rings

    Science.gov (United States)

    Hedman, M. M.; Burns, J. A.; Tiscareno, M. S.; Porco, C. C.

    2009-07-01

    Images of the dusty rings obtained by the Cassini spacecraft in late 2006 and early 2007 reveal unusual structures composed of alternating canted bright and dark streaks in the outer G ring (∼170,000 km from Saturn center), the inner Roche Division (∼138,000 km) and the middle D ring (70,000-73,000 km). The morphology, locations and pattern speeds of these features indicate that they are generated by Lindblad resonances. The structure in the G ring appears to be generated by the 8:7 Inner Lindblad Resonance with Mimas. Based in part on the morphology of the G ring structure, we develop a phenomenological model of Lindblad-resonance-induced structures in faint rings, where the observed variations in the rings' optical depth and brightness are due to alignments and trends in the particles' orbital parameters with semi-major axis. To reproduce the canted character of these structures, this model requires a term in the equations of motion that damps eccentricities. Using this model to interpret the structures in the D ring and Roche Division, we find that the D-ring patterns mimic those predicted at 2:1 Inner Lindblad Resonances and the Roche Division patterns look like those expected at 3:4 Outer Lindblad Resonances. As in the G ring, the effective eccentricity-damping timescale is of order 10-100 days, suggesting that free eccentricities are strongly damped by some mechanism that operates throughout all these regions. However, unlike in the G ring, perturbation forces with multiple periods are required to explain the observed patterns in the D ring and Roche Division. The strongest perturbation periods occur at 10.53, 10.56 and 10.74 hours (only detectable in the D ring) and 10.82 hours (detectable in both the D ring and Roche division). These periods are comparable to the rotation periods of Saturn's atmosphere and magnetosphere. The inferred strength of the perturbation forces required to produce these patterns (and the absence of evidence for other resonances

  17. Synthesis and resolution of a multifunctional inherently chiral calix[4]arene with an ABCD substitution pattern at the wide rim: the effect of a multifunctional structure in the organocatalyst on enantioselectivity in asymmetric reactions.

    Science.gov (United States)

    Shirakawa, Seiji; Kimura, Tomohiro; Murata, Shun-ichi; Shimizu, Shoichi

    2009-02-06

    An efficient synthetic route to inherently chiral calix[4]arenes with an ABCD substitution pattern at the wide rim in the cone conformation was developed for the first time. For the synthesis of inherently chiral ABCD-type calix[4]arenes, first 5,11-dibromo-17-(3,5-dimethylphenyl)-25,26,27,28-tetrapropoxycalix[4]arene (9) was prepared as a key intermediate. Then, functionalization of the calix[4]arene 9 was examined, and highly regioselective monofunctionalization was achieved via selective monolithiation of bromo groups. Various multifunctionalized inherently chiral ABCD-type calix[4]arenes can be synthesized by using this method; thus, the synthesis of inherently chiral phosphine and carboxylic acid derivatives of ABCD-type calix[4]arene was demonstrated. In addition, the aminophenol derivative 1b of an ABCD-type calix[4]arene with a 3,5-dimethylphenyl group at the wide rim was synthesized and resolved into optically pure enantiomers. The chiral calix[4]arene 1b was used as an organocatalyst in asymmetric Michael addition reactions of thiophenols. The effect of the 3,5-dimethylphenyl group at the wide rim of calix[4]arene 1b on enantioselectivity was examined, and a positive effect of the 3,5-dimethylphenyl group was observed.

  18. Structure of weakly periodic rings with potent extended commutators

    OpenAIRE

    Adil Yaqub

    2001-01-01

    A well-known theorem of Jacobson (1964, page 217) asserts that a ring R with the property that, for each x in R, there exists an integer n(x)>1 such that xn(x)=x is necessarily commutative. This theorem is generalized to the case of a weakly periodic ring R with a “sufficient” number of potent extended commutators. A ring R is called weakly periodic if every x in R can be written in the form x=a+b, where a is nilpotent and b is “potent” in the sense that bn(b)=b for some integer n(b)>1. It is...

  19. A No-Reference Sharpness Metric Based on Structured Ringing for JPEG2000 Images

    Directory of Open Access Journals (Sweden)

    Zhipeng Cao

    2014-01-01

    Full Text Available This work presents a no-reference image sharpness metric based on human blur perception for JPEG2000 compressed image. The metric mainly uses a ringing measure. And a blurring measure is used for compensation when the blur is so severe that ringing artifacts are concealed. We used the anisotropic diffusion for the preliminary ringing map and refined it by considering the property of ringing structure. The ringing detection of the proposed metric does not depend on edge detection, which is suitable for high degraded images. The characteristics of the ringing and blurring measures are analyzed and validated theoretically and experimentally. The performance of the proposed metric is tested and compared with that of some existing JPEG2000 sharpness metrics on three widely used databases. The experimental results show that the proposed metric is accurate and reliable in predicting the sharpness of JPEG2000 images.

  20. Celebrating Soft Matter's 10th Anniversary: Topology matters: structure and dynamics of ring polymers.

    Science.gov (United States)

    Richter, D; Goossen, S; Wischnewski, A

    2015-11-28

    Considering topology among all polymer architectures polymer rings are unique, as they are the simplest closed structures without ends. In this review we present recent experimental advances addressing the structure and dynamics of rings. We focus mainly on neutron scattering results that reveal experimental insight on a molecular scale. We first briefly reflect on the progress in ring chemistry that made the experimental access possible. Structural investigations characterizing rings as compact objects in the melts are put into theoretical context. In contrast to the plateau regime common for all other high molecular weight polymer systems, the dynamic modulus of pure ring systems is characterized by a power law decay, while the viscosity displays a much weaker molecular weight dependence as a corresponding linear melt. The dynamics of ring melts is uniquely addressed by neutron spin-echo spectroscopy. The sub-diffusive center of mass motion at short times agrees well with simulation as well as theoretical concepts. In the internal dynamics the basic length scale of the ring molecule, the loop size, manifests itself clearly. The experiments reveal strong evidence for loop motions and call for further theoretical work describing them. Finally, small fractions of ring molecules in linear melts turn out to be very sensitive probes in order to scrutinize the dynamics of the host with the potential to reveal fundamental aspects of the dynamics of branched polymer systems.

  1. Sclerotic rings in mosasaurs (Squamata: Mosasauridae: structures and taxonomic diversity.

    Directory of Open Access Journals (Sweden)

    Momo Yamashita

    Full Text Available Mosasaurs (Squamata: Mosasauridae were a highly diverse, globally distributed group of aquatic lizards in the Late Cretaceous (98-66 million years ago that exhibited a high degree of adaptation to life in water. To date, despite their rich fossil record, the anatomy of complete mosasaur sclerotic rings, embedded in the sclera of the eyeball, has not been thoroughly investigated. We here describe and compare sclerotic rings of four mosasaur genera, Tylosaurus, Platecarpus, Clidastes, and Mosasaurus, for the first time. Two specimens of Tylosaurus and Platecarpus share an exact scleral ossicle arrangement, excepting the missing portion in the specimen of Platecarpus. Furthermore, the exact arrangement and the total count of 14 ossicles per ring are shared between Tylosaurus and numerous living terrestrial lizard taxa, pertaining to both Iguania and Scleroglossa. In contrast, two species of Mosasaurus share the identical count of 12 ossicles and the arrangement with each other, while no living lizard taxa share exactly the same arrangement. Such a mosaic distribution of these traits both among squamates globally and among obligatorily aquatic mosasaurs specifically suggests that neither the ossicle count nor their arrangement played major roles in the aquatic adaptation in mosasaur eyes. All the mosasaur sclerotic rings examined consistently exhibit aperture eccentricity and the scleral ossicles with gently convex outer side. Hitherto unknown to any squamate taxa, one specimen of Platecarpus unexpectedly shows a raised, concentric band of roughened surface on the inner surface of the sclerotic ring. It is possible that one or both of these latter features may have related to adaptation towards aquatic vision in mosasaurs, but further quantitative study of extant reptilian clades containing both terrestrial and aquatic taxa is critical and necessary in order to understand possible adaptive significances of such osteological features.

  2. Sclerotic rings in mosasaurs (Squamata: Mosasauridae): structures and taxonomic diversity.

    Science.gov (United States)

    Yamashita, Momo; Konishi, Takuya; Sato, Tamaki

    2015-01-01

    Mosasaurs (Squamata: Mosasauridae) were a highly diverse, globally distributed group of aquatic lizards in the Late Cretaceous (98-66 million years ago) that exhibited a high degree of adaptation to life in water. To date, despite their rich fossil record, the anatomy of complete mosasaur sclerotic rings, embedded in the sclera of the eyeball, has not been thoroughly investigated. We here describe and compare sclerotic rings of four mosasaur genera, Tylosaurus, Platecarpus, Clidastes, and Mosasaurus, for the first time. Two specimens of Tylosaurus and Platecarpus share an exact scleral ossicle arrangement, excepting the missing portion in the specimen of Platecarpus. Furthermore, the exact arrangement and the total count of 14 ossicles per ring are shared between Tylosaurus and numerous living terrestrial lizard taxa, pertaining to both Iguania and Scleroglossa. In contrast, two species of Mosasaurus share the identical count of 12 ossicles and the arrangement with each other, while no living lizard taxa share exactly the same arrangement. Such a mosaic distribution of these traits both among squamates globally and among obligatorily aquatic mosasaurs specifically suggests that neither the ossicle count nor their arrangement played major roles in the aquatic adaptation in mosasaur eyes. All the mosasaur sclerotic rings examined consistently exhibit aperture eccentricity and the scleral ossicles with gently convex outer side. Hitherto unknown to any squamate taxa, one specimen of Platecarpus unexpectedly shows a raised, concentric band of roughened surface on the inner surface of the sclerotic ring. It is possible that one or both of these latter features may have related to adaptation towards aquatic vision in mosasaurs, but further quantitative study of extant reptilian clades containing both terrestrial and aquatic taxa is critical and necessary in order to understand possible adaptive significances of such osteological features.

  3. Identification of novel SNPs of ABCD1, ABCD2, ABCD3, and ABCD4 genes in patients with X-linked adrenoleukodystrophy (ALD) based on comprehensive resequencing and association studies with ALD phenotypes

    Science.gov (United States)

    Matsukawa, Takashi; Asheuer, Muriel; Takahashi, Yuji; Goto, Jun; Suzuki, Yasuyuki; Shimozawa, Nobuyuki; Takano, Hiroki; Onodera, Osamu; Nishizawa, Masatoyo; Aubourg, Patrick

    2010-01-01

    Adrenoleukodystrophy (ALD) is an X-linked disorder affecting primarily the white matter of the central nervous system occasionally accompanied by adrenal insufficiency. Despite the discovery of the causative gene, ABCD1, no clear genotype–phenotype correlations have been established. Association studies based on single nucleotide polymorphisms (SNPs) identified by comprehensive resequencing of genes related to ABCD1 may reveal genes modifying ALD phenotypes. We analyzed 40 Japanese patients with ALD. ABCD1 and ABCD2 were analyzed using a newly developed microarray-based resequencing system. ABCD3 and ABCD4 were analyzed by direct nucleotide sequence analysis. Replication studies were conducted on an independent French ALD cohort with extreme phenotypes. All the mutations of ABCD1 were identified, and there was no correlation between the genotypes and phenotypes of ALD. SNPs identified by the comprehensive resequencing of ABCD2, ABCD3, and ABCD4 were used for association studies. There were no significant associations between these SNPs and ALD phenotypes, except for the five SNPs of ABCD4, which are in complete disequilibrium in the Japanese population. These five SNPs were significantly less frequently represented in patients with adrenomyeloneuropathy (AMN) than in controls in the Japanese population (p = 0.0468), whereas there were no significant differences in patients with childhood cerebral ALD (CCALD). The replication study employing these five SNPs on an independent French ALD cohort, however, showed no significant associations with CCALD or pure AMN. This study showed that ABCD2, ABCD3, and ABCD4 are less likely the disease-modifying genes, necessitating further studies to identify genes modifying ALD phenotypes. Electronic supplementary material The online version of this article (doi:10.1007/s10048-010-0253-6) contains supplementary material, which is available to authorized users. PMID:20661612

  4. Structure and catalytic activation of the TRIM23 RING E3 ubiquitin ligase: DAWIDZIAK et al.

    Energy Technology Data Exchange (ETDEWEB)

    Dawidziak, Daria M. [Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville Virginia; Sanchez, Jacint G. [Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville Virginia; Wagner, Jonathan M. [Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville Virginia; Ganser-Pornillos, Barbie K. [Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville Virginia; Pornillos, Owen [Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville Virginia

    2017-07-24

    Tripartite motif (TRIM) proteins comprise a large family of RING-type ubiquitin E3 ligases that regulate important biological processes. An emerging general model is that TRIMs form elongated antiparallel coiled-coil dimers that prevent interaction of the two attendant RING domains. The RING domains themselves bind E2 conjugating enzymes as dimers, implying that an active TRIM ligase requires higher-order oligomerization of the basal coiled-coil dimers. Here, we report crystal structures of the TRIM23 RING domain in isolation and in complex with an E2–ubiquitin conjugate. Our results indicate that TRIM23 enzymatic activity requires RING dimerization, consistent with the general model of TRIM activation.

  5. Optical system defect propagation in ABCD systems

    DEFF Research Database (Denmark)

    McKinley, W.G.; Yura, H.T.; Hanson, Steen Grüner

    1988-01-01

    We describe how optical system defects (tilt/jitter, decenter, and despace) propagate through an arbitrary paraxial optical system that can be described by an ABCD ray transfer matrix. A pedagogical example is given that demonstrates the effect of alignment errors on a typical optical system...

  6. Self-gravity wake structures in Saturn's a ring revealed by Cassini vims

    Science.gov (United States)

    Hedman, M.M.; Nicholson, P.D.; Salo, H.; Wallis, B.D.; Buratti, B.J.; Baines, K.H.; Brown, R.H.; Clark, R.N.

    2007-01-01

    During the summer of 2005, the Visual and Infrared Mapping Spectrometer onboard the Cassini spacecraft observed a series of occultations of the star o Ceti (Mira) by Saturn's rings. These observations revealed pronounced variations in the optical depth of the A ring with longitude, which can be attributed to oriented structures in the rings known as self-gravity wakes. While the wakes themselves are only tens of meters across and below the resolution of the measurements, we are able to obtain information about the orientation and shapes of these structures by comparing the observed transmission at different longitudes with predictions from a simple model. Our findings include the following: (1) The orientation of the wakes varies systematically with radius, trailing by between 64?? and 72?? relative to the local radial direction. (2) The maximum transmission peaks at roughly 8% for B = 3.45?? in the middle A ring (???129,000 km). (3) Both the wake orientation and maximum transmission vary anomalously in the vicinity of two strong density waves (Janus 5:4 and Mimas 5:3). (4) The ratio of the wake vertical thickness H to the wake pattern wavelength ?? (assuming infinite, straight, regularly-spaced wake structures) varies from 0.12 to 0.09 across the A ring. Gravitational instability theory predicts ?? ??? 60 m, which suggests that the wake structures in the A ring are only ???6 m thick. ?? 2007. The American Astronomical Society. All rights reserved.

  7. Active vibration control of ring-stiffened cylindrical shell structure using macro fiber composite actuators.

    Science.gov (United States)

    Sohn, Jung Woo; Jeon, Juncheol; Choi, Seung-Bok

    2014-10-01

    Vibration control performance of the ring-stiffened cylindrical shell structure is experimentally evaluated in this work. In order to achieve high control performance, advanced flexible piezoelectric actuator whose commercial name is Macro-Fiber Composite (MFC) is adapted to the shell structure. Governing equation is derived by finite element method and dynamic characteristics are investigated from the modal analysis results. Ring-stiffened cylindrical shell structure is then manufactured and modal test is conducted to verify modal analysis results. An optimal controller is designed and experimentally realized to the proposed shell structure system. Vibration control performance is experimentally evaluated in time domain and verified by simulated control results.

  8. Performance of the ABCD and ABCD2 scores in TIA patients with carotid stenosis and atrial fibrillation.

    Science.gov (United States)

    Koton, S; Rothwell, P M

    2007-01-01

    It has been suggested that scores for risk stratification of TIA patients might not identify patients with carotid stenosis or atrial fibrillation (AF) and that this might undermine the usefulness of such scores. In patients with TIA in the Oxford Vascular Study, we studied the associations between ABCD and ABCD2 scores, the presence of > or =50% ipsilateral carotid stenosis or AF, and the risk of stroke at 7 days. Among 285 TIA patients (from 559 referrals of possible TIA), 69 (24.2%) had either > or =50% carotid stenosis (n = 29) or AF (n = 42), or both (n = 2). Although the ABCD and ABCD2 scores were highly predictive of stroke at 7 days (p or =50% carotid stenosis or AF. However, the scores did predict the 7-day stroke risk in patients with these pathologies: ABCD score (trend-p = 0.05); ABCD2 (trend-p = 0.03). Five of the 6 patients with AF or symptomatic stenosis who had a stroke within 7 days of their TIA had an ABCD score of > or =5 and all 6 had an ABCD2 score of > or =4. The ABCD and ABCD2 risk scores appear to identify patients with > or =50% carotid stenosis or AF who are at high risk of stroke. However, these findings should be interpreted with caution due to the small number of outcomes among these subgroups, and further validations are necessary.

  9. Traffic Load on Interconnection Lines of Generalized Double Ring Network Structures

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Riaz, Muhammad Tahir; Madsen, Ole Brun

    2005-01-01

    Generalized Double Ring (N2R) network structures possess a number of good properties, but being not planar they are hard to physically embed in communication networks. However, if some of the lines, the interconnection lines, are implemented by wireless technologies, the remaining structure...... consists of two planar rings, which are easily embedded by fiber or other wired solutions. It is shown that for large N2R structures, the interconnection lines carry notably lower loads than the other lines if shortest-path routing is used, and the effects of two other routing schemes are explored, leading...

  10. Traffic Load on Interconnection Lines of Generalized Double Ring Network Structures

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Riaz, Muhammad Tahir; Madsen, Ole Brun

    2004-01-01

    Generalized Double Ring (N2R) network structures possess a number of good properties, but being not planar they are hard to physically embed in communication networks. However, if some of the lines, the interconnection lines, are implemented by wireless technologies, the remaining structure...... consists of two planar rings, which are easily embedded by fiber or other wired solutions. It is shown that for large N2R structures, the interconnection lines carry notably lower loads than the other lines if shortest-path routing is used, and the effects of two other routing schemes are explored, leading...

  11. Cobalt double-ring and double-dot structures: Magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    López-Urías, F., E-mail: flo@ipicyt.edu.mx [Advanced Materials Department, IPICYT, Camino a la presa San José 2055, Col. Lomas 4a sección, 78216, San Luis Potosí S.L.P., México (Mexico); Torres-Heredia, J.J. [Instituto Tecnológico Superior de Las Choapas, Col. J. M. Rosa do, 96980, Las Choapas, Veracruz (Mexico); Muñoz-Sandoval, E. [Advanced Materials Department, IPICYT, Camino a la presa San José 2055, Col. Lomas 4a sección, 78216, San Luis Potosí S.L.P., México (Mexico)

    2016-02-15

    The magnetization reversal mechanism of nanostructures of cobalt double-rings (D-rings) and double-dots (D-dots) is investigated in the framework of micromagnetic simulations. The arrays contain two identical coupled rings (wide and narrow) or dots with outer diameter of 200 nm and thicknesses ranging from 2–20 nm. Hysteresis loops, dipole–dipole and exchange energies are systematically calculated for the cases of the structures touching and the structures with a 50-nm inter-magnet separation; moreover, magnetization states along the hysteresis curve are analyzed. The results of both dot and ring D-magnets are compared with the corresponding individual magnets. Our results reveal that all D-ring (in contact and separated) arrays containing narrow rings exhibit non-null remanent magnetization; furthermore, higher coercive fields are promoted when the magnet thickness is increased. It is observed that the magnetization reversal is driven mainly by a clockwise rotation of onion-states, followed by states of frustrated vortices. Our results could help improve the understanding of the magnetic interactions in nanomagnet arrays.

  12. Effect of ABCD transformations on beam paraxiality.

    Science.gov (United States)

    Vaveliuk, Pablo; Martinez-Matos, Oscar

    2011-12-19

    The limits of the paraxial approximation for a laser beam under ABCD transformations is established through the relationship between a parameter concerning the beam paraxiality, the paraxial estimator, and the beam second-order moments. The applicability of such an estimator is extended to an optical system composed by optical elements as mirrors and lenses and sections of free space, what completes the analysis early performed for free-space propagation solely. As an example, the paraxiality of a system composed by free space and a spherical thin lens under the propagation of Hermite-Gauss and Laguerre-Gauss modes is established. The results show that the the paraxial approximation fails for a certain feasible range of values of main parameters. In this sense, the paraxial estimator is an useful tool to monitor the limits of the paraxial optics theory under ABCD transformations.

  13. Reconnaissance survey of the Duolun ring structure in Inner Mongolia: Not an impact structure

    Science.gov (United States)

    Xu, Xiaoming; Kenkmann, Thomas; Xiao, Zhiyong; Sturm, Sebastian; Metzger, Nicolai; Yang, Yu; Weimer, Daniela; Krietsch, Hannes; Zhu, Meng-Hua

    2017-09-01

    The Duolun basin, which is located in Inner Mongolia, China, has been proposed to be an impact structure with an apparent rim diameter of about 70, or even 170 km. The designation as an impact structure was based on its nearly circular topography, consisting of an annular moat that surrounds an inner hummocky region, and the widespread occurrences of various igneous rocks, polymict breccias, and deformed crustal rocks. Critical shock metamorphic evidence is not available to support the impact hypothesis. We conducted two independent reconnaissance field surveys to this area and studied the lithology both within and outside of the ring structure. We collected samples from all lithologies that might contain evidence of shock metamorphism as suggested by their locations, especially those sharing similar appearances with impact breccias, suevites, impact melt rocks, and shatter cones. Field investigation, together with thin-section examination, discovered that the suspected impact melt rocks are actually Early Cretaceous and Late Jurassic lava flows and pyroclastic deposits of rhyolitic to trachytic compositions, and the interpreted impact glass is typical volcanic glass. Petrographic analyses of all the samples reveal no indications for shock metamorphic overprint. All these lines of evidence suggest that the Duolun basin was not formed through impact cratering. The structural deformation and spatial distribution pattern of the igneous rocks suggest that the Duolun basin is most likely a Jurassic-Cretaceous complex rhyolite caldera system that has been partly filled with sediments forming an annular basin, followed by resurgent doming of the central area.

  14. Structure of the Mimas 5:3 Bending Wave in Saturn's Rings

    Science.gov (United States)

    Sega, Daniel D.; Colwell, Josh E.

    2016-10-01

    Saturn's moon Mimas is on an inclined orbit with several strong vertical orbital resonances in Saturn's rings. The 5:3 inner vertical resonance with Mimas lies in the outer A ring and produces a prominent spiral bending wave (BW) that propagates away from Mimas. While dozens of density waves in Saturn's rings have been analyzed to determine local surface mass densities and viscosities, the number of bending waves is limited by the requirement for a moon on an inclined orbit and because, unlike the Lindblad resonances that excite density waves, there can be no first order vertical resonances. The Mimas 5:3 BW is the most prominent in the ring system. Bending wave theory was initially developed by Shu et al. (1983, Icarus, 53, 185-206) following the Voyager encounters with Saturn. Later, Gresh et al. (1986, Icarus, 68, 481-502) modeled radio science occultation data of the Mimas 5:3 BW with an imperfect fit to the theory. The multitude of high resolution stellar occultations observed by Cassini UVIS provides an opportunity to reconstruct the full three-dimensional structure of this wave and learn more about local ring properties. Occultations at high elevation angles out of the ring plane are insensitive to the wave structure due to the small angles of the vertical warping of the rings in the wave. They thus reveal the underlying structure in the wave region. There is a symmetric increase in optical depth throughout the Mimas 5:3 BW region. This may be due to an increase in the abundance of small particles without a corresponding increase in surface mass density. We include this feature in a ray-tracing model of the vertical structure of the wave and fit it to multiple UVIS occultations. The observed amplitude of the wave and its damping behavior of are not well-described by the Shu et al. model, which assumes a fluid-like damping mechanism. A different damping behavior of the ring, perhaps radially varying across the wave region due to differences in the particle

  15. Microwave metamaterial absorber based on multiple square ring structures

    Directory of Open Access Journals (Sweden)

    Weicheng Zhou

    2015-11-01

    Full Text Available In this paper, we report the design, analysis, and simulation of quintuple-band metamaterial absorber (MMA in the microwave region. The absorber is constructed of a delicate periodic patterned structures and a metallic background plane, separated by a dielectric substrate. By manipulating the periodic patterned structures, high absorption can be obtained at five specific resonance frequencies. Moreover, the significantly high absorptions of quintuple-peaks are persistent with polarization independence, and the influence of angle of incidence for both TE and TM modes was also elucidated. For explaining the absorption mechanism of proposed structures, the electric and magnetic field distributions and resistance matching principal were given. Importantly, the design idea has the ability to be extended to other frequencies, like terahertz, infrared and optical frequencies.

  16. Microwave metamaterial absorber based on multiple square ring structures

    Science.gov (United States)

    Zhou, Weicheng; Wang, Pinghe; Wang, Nan; Jiang, Wei; Dong, Xiaochun; Hu, Song

    2015-11-01

    In this paper, we report the design, analysis, and simulation of quintuple-band metamaterial absorber (MMA) in the microwave region. The absorber is constructed of a delicate periodic patterned structures and a metallic background plane, separated by a dielectric substrate. By manipulating the periodic patterned structures, high absorption can be obtained at five specific resonance frequencies. Moreover, the significantly high absorptions of quintuple-peaks are persistent with polarization independence, and the influence of angle of incidence for both TE and TM modes was also elucidated. For explaining the absorption mechanism of proposed structures, the electric and magnetic field distributions and resistance matching principal were given. Importantly, the design idea has the ability to be extended to other frequencies, like terahertz, infrared and optical frequencies.

  17. Insect-inspired wing actuation structures based on ring-type resonators

    NARCIS (Netherlands)

    Bolsman, C.T.; Goosen, J.F.L.; Van Keulen, F.

    2008-01-01

    In this paper, we illustrate and study the opportunities of resonant ring type structures as wing actuation mechanisms for a flapping wing Micro Air Vehicle (MAV). Various design alternatives are presented and studied based on computational and physical models. Insects provide an excellent source of

  18. Combined Structural and Compositional Evolution of Planetary Rings Due to Micrometeoroid Impacts and Ballistic Transport

    Science.gov (United States)

    Estrada, Paul R.; Durisen, Richard H.; Cuzzi, Jeffrey N.; Morgan, Demitri A.

    2015-01-01

    We introduce improved numerical techniques for simulating the structural and compositional evolution of planetary rings due to micrometeoroid bombardment and subsequent ballistic transport of impact ejecta. Our current, robust code is capable of modeling structural changes and pollution transport simultaneously over long times on both local and global scales. In this paper, we describe the methodology based on the original structural code of Durisen et al. (1989, Icarus 80, 136-166) and on the pollution transport code of Cuzzi and Estrada (1998, Icarus 132, 1-35). We provide demonstrative simulations to compare with, and extend upon previous work, as well as examples of how ballistic transport can maintain the observed structure in Saturn's rings using available Cassini occultation optical depth data. In particular, we explicitly verify the claim that the inner B (and presumably A) ring edge can be maintained over long periods of time due to an ejecta distribution that is heavily biased in the prograde direction through a balance between the sharpening effects of ballistic transport and the broadening effects of viscosity. We also see that a "ramp"-like feature forms over time just inside that edge. However, it does not remain linear for the duration of the runs presented here unless a less steep ejecta velocity distribution is adopted. We also model the C ring plateaus and find that their outer edges can be maintained at their observed sharpness for long periods due to ballistic transport. We hypothesize that the addition of a significant component of a retrograde-biased ejecta distribution may help explain the linearity of the ramp and is probably essential for maintaining the sharpness of C ring plateau inner edges. This component would arise for the subset of micrometeoroid impacts which are destructive rather than merely cratering. Such a distribution will be introduced in future work.

  19. The ABCD of topological recursion

    DEFF Research Database (Denmark)

    Andersen, Jorgen Ellegaard; Borot, Gaëtan; Chekhov, Leonid O.

    2017-01-01

    Kontsevich and Soibelman reformulated and slightly generalised the topological recursion of math-ph/0702045, seeing it as a quantization of certain quadratic Lagrangians in T*V for some vector space V. KS topological recursion is a procedure which takes as initial data a quantum Airy structure - ...

  20. Correlation between magnetic spin structure and the three-dimensional geometry in chemically synthesized nanoscale magnetite rings

    DEFF Research Database (Denmark)

    Eltschka, M.; Klaui, M.; Rudiger, U

    2008-01-01

    The correlation between magnetic spin structure and geometry in nanoscale chemically synthesized Fe3O4 rings has been investigated by transmission electron microscopy. We find primarily the flux closure vortex states but in rings with thickness variations, an effective stray field occurs. Using t....... The interaction between exchange coupled rings leads to antiparallel vortex states and extended onion states. (c) 2008 American Institute of Physics....

  1. Using multi-ring structure for suppression of mode competition in stable single-longitudinal-mode erbium fiber laser

    Science.gov (United States)

    Yeh, Chien-Hung; Huang, Tzu-Jung; Yang, Zi-Qing; Chow, Chi-Wai

    2017-12-01

    In this demonstration, a stable and tunable single-longitudinal-mode (SLM) erbium-doped fiber (EDF) laser with multiple-ring configuration is proposed and investigated. The proposed compound-ring structure can create different free spectrum ranges (FSRs) to result in the mode-filter effect based on the Vernier effect for suppressing the other modes. Additionally, the output stabilization of power and wavelength in the proposed EDF multiple-ring laser are also discussed.

  2. ABCD Matrix Method a Case Study

    CERN Document Server

    Seidov, Zakir F; Yahalom, Asher

    2004-01-01

    In the Israeli Electrostatic Accelerator FEL, the distance between the accelerator's end and the wiggler's entrance is about 2.1 m, and 1.4 MeV electron beam is transported through this space using four similar quadrupoles (FODO-channel). The transfer matrix method (ABCD matrix method) was used for simulating the beam transport, a set of programs is written in the several programming languages (MATHEMATICA, MATLAB, MATCAD, MAPLE) and reasonable agreement is demonstrated between experimental results and simulations. Comparison of ABCD matrix method with the direct "numerical experiments" using EGUN, ELOP, and GPT programs with and without taking into account the space-charge effects showed the agreement to be good enough as well. Also the inverse problem of finding emittance of the electron beam at the S1 screen position (before FODO-channel), by using the spot image at S2 screen position (after FODO-channel) as function of quad currents, is considered. Spot and beam at both screens are described as tilted eel...

  3. Asymmetric ring structure of Vps4 required for ESCRT-III disassembly

    Science.gov (United States)

    Caillat, Christophe; Macheboeuf, Pauline; Wu, Yuanfei; McCarthy, Andrew A.; Boeri-Erba, Elisabetta; Effantin, Gregory; Göttlinger, Heinrich G.; Weissenhorn, Winfried; Renesto, Patricia

    2015-12-01

    The vacuolar protein sorting 4 AAA-ATPase (Vps4) recycles endosomal sorting complexes required for transport (ESCRT-III) polymers from cellular membranes. Here we present a 3.6-Å X-ray structure of ring-shaped Vps4 from Metallosphera sedula (MsVps4), seen as an asymmetric pseudohexamer. Conserved key interface residues are shown to be important for MsVps4 assembly, ATPase activity in vitro, ESCRT-III disassembly in vitro and HIV-1 budding. ADP binding leads to conformational changes within the protomer, which might propagate within the ring structure. All ATP-binding sites are accessible and the pseudohexamer binds six ATP with micromolar affinity in vitro. In contrast, ADP occupies one high-affinity and five low-affinity binding sites in vitro, consistent with conformational asymmetry induced on ATP hydrolysis. The structure represents a snapshot of an assembled Vps4 conformation and provides insight into the molecular motions the ring structure undergoes in a concerted action to couple ATP hydrolysis to ESCRT-III substrate disassembly.

  4. Electronic structures of GaAs/AlxGa1-xAs quantum double rings

    Directory of Open Access Journals (Sweden)

    Li Shu-Shen

    2006-01-01

    Full Text Available AbstractIn the framework of effective mass envelope function theory, the electronic structures of GaAs/AlxGa1-xAs quantum double rings (QDRs are studied. Our model can be used to calculate the electronic structures of quantum wells, wires, dots, and the single ring. In calculations, the effects due to the different effective masses of electrons and holes in GaAs and AlxGa1-xAs and the valence band mixing are considered. The energy levels of electrons and holes are calculated for different shapes of QDRs. The calculated results are useful in designing and fabricating the interrelated photoelectric devices. The single electron states presented here are useful for the study of the electron correlations and the effects of magnetic fields in QDRs.

  5. Modelling nonlinearity in superconducting split ring resonator and its effects on metamaterial structures

    Science.gov (United States)

    Mazdouri, Behnam; Mohammad Hassan Javadzadeh, S.

    2017-09-01

    Superconducting materials are intrinsically nonlinear, because of nonlinear Meissner effect (NLME). Considering nonlinear behaviors, such as harmonic generation and intermodulation distortion (IMD) in superconducting structures, are very important. In this paper, we proposed distributed nonlinear circuit model for superconducting split ring resonators (SSRRs). This model can be analyzed by using Harmonic Balance method (HB) as a nonlinear solver. Thereafter, we considered a superconducting metamaterial filter which was based on split ring resonators and we calculated fundamental and third-order IMD signals. There are good agreement between nonlinear results from proposed model and measured ones. Additionally, based on the proposed nonlinear model and by using a novel method, we considered nonlinear effects on main parameters in the superconducting metamaterial structures such as phase constant (β) and attenuation factor (α).

  6. Irradiation of the ATLAS SCT hybrid equipped with ABCD chips

    CERN Document Server

    Buttar, C M; Dabrowski, W; Dawson, I; Eklund, L; Harper, R; Kaplon, J; Kramberger, G; Kudlaty, G; Lacasta, C; Macina, Daniela; Mandic, I; Mikuz, M; Wolter, M; Zsenei, A

    1999-01-01

    An ATLAS SCT hybrid equipped with 3 ABCD2T chips and 3 ABCD2NT chips has been irradiated with 24 GeV protons from the PS accelerator at CERN. Another hybrid has been irradiated with neutrons from the reactor in Ljubljana. After a total fluence of 3*10^14 p/cm2 at CERN and 2*10^14 n/cm2 from reactor the ABCD2T chips stay fully operational. Their parameters remain within specification and the increased offset spread can be corrected using TrimDacs.

  7. Molecular structure, interatomic interactions and vibrational analysis of 1,4-diazabicyclo[3.2.1]octane parent ring system

    Science.gov (United States)

    Britvin, Sergey N.; Rumyantsev, Andrey M.; Zobnina, Anastasia E.; Padkina, Marina V.

    2017-02-01

    Molecular structure of 1,4-diazabicyclo[3.2.1]octane, a parent ring of TAN1251 family of alkaloids, is herein characterized for the first time in comparison with the structure of nortropane (8-azabicyclo[3.2.1]octane), the parent framework of tropane ring system. The methods of study involve X-ray structural analysis, DFT geometry optimizations with infrared frequency calculations followed by natural bond orbital (NBO) analysis, and vibrational analysis of infrared spectrum.

  8. Ringed Structures of the HD 163296 Protoplanetary Disk Revealed by ALMA.

    Science.gov (United States)

    Isella, Andrea; Guidi, Greta; Testi, Leonardo; Liu, Shangfei; Li, Hui; Li, Shengtai; Weaver, Erik; Boehler, Yann; Carperter, John M; De Gregorio-Monsalvo, Itziar; Manara, Carlo F; Natta, Antonella; Pérez, Laura M; Ricci, Luca; Sargent, Anneila; Tazzari, Marco; Turner, Neal

    2016-12-16

    We present Atacama Large Millimeter and Submillimeter Array observations of the protoplanetary disk around the Herbig Ae star HD 163296 that trace the spatial distribution of millimeter-sized particles and cold molecular gas on spatial scales as small as 25 astronomical units (A.U.). The image of the disk recorded in the 1.3 mm continuum emission reveals three dark concentric rings that indicate the presence of dust depleted gaps at about 60, 100, and 160 A.U. from the central star. The maps of the ^{12}CO, ^{13}CO, and C^{18}O J=2-1 emission do not show such structures but reveal a change in the slope of the radial intensity profile across the positions of the dark rings in the continuum image. By comparing the observations with theoretical models for the disk emission, we find that the density of CO molecules is reduced inside the middle and outer dust gaps. However, in the inner ring there is no evidence of CO depletion. From the measurements of the dust and gas densities, we deduce that the gas-to-dust ratio varies across the disk and, in particular, it increases by at least a factor 5 within the inner dust gap compared to adjacent regions of the disk. The depletion of both dust and gas suggests that the middle and outer rings could be due to the gravitational torque exerted by two Saturn-mass planets orbiting at 100 and 160 A.U. from the star. On the other hand, the inner dust gap could result from dust accumulation at the edge of a magnetorotational instability dead zone, or from dust opacity variations at the edge of the CO frost line. Observations of the dust emission at higher angular resolution and of molecules that probe dense gas are required to establish more precisely the origins of the dark rings observed in the HD 163296 disk.

  9. Similar Ring Structures on Mars and Tibetan Plateau confirm recent tectonism on Martian Northern polar region

    Science.gov (United States)

    Anglés, A.; Li, Y. L.

    2017-10-01

    The polar regions of Mars feature layered deposits, some of which exist as enclosed zoning structures. These deposits raised strong interest since their discovery and still remain one of the most controversial features on Mars. Zoning structures that are enclosed only appear in the Northern polar region, where the disappearance of water bodies may have left behind huge deposits of evaporate salts. The origin of the layered deposits has been widely debated. Here we propose that the enclosed nature of the zoning structures indicates the result of recent tectonism. We compared similar structures at an analogue site located in the western Qaidam Basin of Tibetan Plateau, a unique tectonic setting with abundant saline deposits. The enclosed structures, which we term Ring Structures, in both the analogue site and in the Northern polar region of Mars, were formed by uplift induced pressurization and buoyancy of salts as the result of recent tectonic activity.

  10. CN rings in full protoplanetary disks around young stars as probes of disk structure

    Science.gov (United States)

    Cazzoletti, P.; van Dishoeck, E. F.; Visser, R.; Facchini, S.; Bruderer, S.

    2018-01-01

    Aims: Bright ring-like structure emission of the CN molecule has been observed in protoplanetary disks. We investigate whether such structures are due to the morphology of the disk itself or if they are instead an intrinsic feature of CN emission. With the intention of using CN as a diagnostic, we also address to which physical and chemical parameters CN is most sensitive. Methods: A set of disk models were run for different stellar spectra, masses, and physical structures via the 2D thermochemical code DALI. An updated chemical network that accounts for the most relevant CN reactions was adopted. Results: Ring-shaped emission is found to be a common feature of all adopted models; the highest abundance is found in the upper outer regions of the disk, and the column density peaks at 30-100 AU for T Tauri stars with standard accretion rates. Higher mass disks generally show brighter CN. Higher UV fields, such as those appropriate for T Tauri stars with high accretion rates or for Herbig Ae stars or for higher disk flaring, generally result in brighter and larger rings. These trends are due to the main formation paths of CN, which all start with vibrationally excited H_2^* molecules, that are produced through far ultraviolet (FUV) pumping of H2. The model results compare well with observed disk-integrated CN fluxes and the observed location of the CN ring for the TW Hya disk. Conclusions: CN rings are produced naturally in protoplanetary disks and do not require a specific underlying disk structure such as a dust cavity or gap. The strong link between FUV flux and CN emission can provide critical information regarding the vertical structure of the disk and the distribution of dust grains which affects the UV penetration, and could help to break some degeneracies in the SED fitting. In contrast with C2H or c-C3H2, the CN flux is not very sensitive to carbon and oxygen depletion.

  11. Stereochemical Basis for a Unified Structure Activity Theory of Aromatic and Heterocyclic Rings in Selected Opioids and Opioid Peptides

    Directory of Open Access Journals (Sweden)

    Joel S. Goldberg

    2010-02-01

    Full Text Available This paper presents a novel unified theory of the structure activity relationship of opioids and opioid peptides. It is hypothesized that a virtual or known heterocyclic ring exists in all opioids which have activity in humans, and this ring occupies relative to the aromatic ring of the drug, approximately the same plane in space as the piperidine ring of morphine. Since the rings of morphine are rigid, and the aromatic and piperidine rings are critical structural components for morphine’s analgesic properties, the rigid morphine molecule allows for approximations of the aromatic and heterocyclic relationships in subsequent drug models where bond rotations are common. This hypothesis and five propositions are supported by stereochemistry and experimental observations. Proposition #1 The structure of morphine provides a template. Proposition #2 Steric hindrance of some centric portion of the piperidine ring explains antagonist properties of naloxone, naltrexone and alvimopam. Proposition #3 Methadone has an active conformation which contains a virtual heterocyclic ring which explains its analgesic activity and racemic properties. Proposition #4 The piperidine ring of fentanyl can assume the morphine position under conditions of nitrogen inversion. Proposition #5 The first 3 amino acid sequences of beta endorphin (l-try-gly-gly and the active opioid dipeptide, l-tyr-pro, (as a result of a peptide turn and zwitterion bonding form a virtual piperazine-like ring which is similar in size, shape and location to the heterocyclic rings of morphine, meperidine, and methadone. Potential flaws in this theory are discussed. This theory could be important for future analgesic drug design.

  12. Stereochemical basis for a unified structure activity theory of aromatic and heterocyclic rings in selected opioids and opioid peptides.

    Science.gov (United States)

    Goldberg, Joel S

    2010-02-18

    This paper presents a novel unified theory of the structure activity relationship of opioids and opioid peptides. It is hypothesized that a virtual or known heterocyclic ring exists in all opioids which have activity in humans, and this ring occupies relative to the aromatic ring of the drug, approximately the same plane in space as the piperidine ring of morphine. Since the rings of morphine are rigid, and the aromatic and piperidine rings are critical structural components for morphine's analgesic properties, the rigid morphine molecule allows for approximations of the aromatic and heterocyclic relationships in subsequent drug models where bond rotations are common. This hypothesis and five propositions are supported by stereochemistry and experimental observations.Proposition #1 The structure of morphine provides a template. Proposition #2 Steric hindrance of some centric portion of the piperidine ring explains antagonist properties of naloxone, naltrexone and alvimopam. Proposition #3 Methadone has an active conformation which contains a virtual heterocyclic ring which explains its analgesic activity and racemic properties. Proposition #4 The piperidine ring of fentanyl can assume the morphine position under conditions of nitrogen inversion. Proposition #5 The first 3 amino acid sequences of beta endorphin (l-try-gly-gly) and the active opioid dipeptide, l-tyr-pro, (as a result of a peptide turn and zwitterion bonding) form a virtual piperazine-like ring which is similar in size, shape and location to the heterocyclic rings of morphine, meperidine, and methadone. Potential flaws in this theory are discussed.This theory could be important for future analgesic drug design.

  13. Remote sensing observations of the coherent and non-coherent ring structures in the vicinity of Lesser Antilles

    Directory of Open Access Journals (Sweden)

    R. C. Cruz Gómez

    2007-03-01

    Full Text Available The North Brazil Current Rings (NBCR penetration into the Caribbean Sea is being investigated by employing a merged altimeter-derived sea height anomaly (TOPEX/Poseidon, Jason-1 and ERS-1, 2, the ocean surface color data (SeaWiFS and Global Drifter Program information. Four strategies are being applied to process the data: (1 calculations of the Okubo-Weiss parameter for NBCR identification, (2 longitude-time plots (also known as Hovmöller diagrams, (3 two-dimensional Radon transforms and (4 two-dimensional Fourier transforms.

    A twofold NBCR structure has been detected in the region under investigation. The results have shown that NBC rings mainly propagate into the Caribbean Sea along two principal pathways (near 12° N and 17° N in the ring translation corridor. Thus, rings following the southern pathway in the fall-winter period can enter through very shallow southern straits as non-coherent structures. A different behavior is observed near the northern pathway (~17° N, where NBC rings are thought to have a coherent structure during their squeezing into the eastern Caribbean, i.e. conserving the principal characteristics of the incident rings. We attribute this difference in the rings' behavior to the vertical scales of the rings and to the bottom topography features in the vicinity of the Lesser Antilles.

  14. ABCD1 Gene Mutations in Chinese Patients with ALD

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2005-08-01

    Full Text Available Thirty-two different ABCD1 mutations were identified by direct sequencing of polymerase chain reaction products in 34 unrelated Chinese X-linked adrenoleukodystrophy (ALD patients examined at Peking University First Hospital, Beijing, PRC.

  15. Strain distribution and band structure of InAs/GaAs quantum ring superlattice

    Science.gov (United States)

    Mughnetsyan, Vram; Kirakosyan, Albert

    2017-12-01

    The elastic strain distribution and the band structure of InAs/GaAs one-layer quantum ring superlattice with square symmetry has been considered in this work. The Green's function formalism based on the method of inclusions has been implied to calculate the components of the strain tensor, while the combination of Green's function method with the Fourier transformation to momentum space in Pikus-Bir Hamiltonian has been used for obtaining the miniband energy dispersion surfaces via the exact diagonalization procedure. The dependencies of the strain tensor components on spatial coordinates are compared with ones for single quantum ring and are in good agreement with previously obtained results for cylindrical quantum disks. It is shown that strain significantly affects the miniband structure of the superlattice and has contribution to the degeneracy lifting effect due to heavy hole-light hole coupling. The demonstrated method is simple and provides reasonable results for comparatively small Hamiltonian matrix. The obtained results may be useful for further investigation and construction of novel devices based on quantum ring superlattices.

  16. The ABCD study of neurodevelopment: Identifying neurocircuit targets for prevention and treatment of adolescent substance abuse.

    Science.gov (United States)

    Bjork, James M; Straub, Lisa K; Provost, Rosellen G; Neale, Michael C

    2017-06-01

    Substance use disorders (SUD) can be considered developmental disorders in light of their frequent origins in substance initiation during adolescence. Cross-sectional functional magnetic resonance imaging (fMRI) studies of adolescent substance users or adolescents with SUD have indicated aberrations in brain structures or circuits implicated in motivation, self-control, and mood-regulation. However, attributing these differences to the neurotoxicological effects of chronic substance use has been problematic in that these circuits are also aberrant in at-risk children, such as those with prenatal substance exposure, externalizing disorders (such as conduct disorder), or prodromal internalizing disorders such as depression. To better isolate the effects of substance exposure on the adolescent brain, the newly-launched Adolescent Brain Cognitive Development (ABCD) study, funded by the National Institutes of Health, will follow the neurodevelopmental trajectories of over 11,000 American 9/10-year-olds for 10 years, into emerging adulthood. This study will provide a rich open-access dataset on longitudinal interactions of neurodevelopment, environmental exposures, and childhood psychopathology that confer addiction risk. The ABCD twin study will further clarify genetic versus experiential influences (e.g., substance use) on neurodevelopmental and psychosocial outcomes. Neurocircuitry thought to regulate mood and behavior has been directly normalized by administration of psychoactive medications and by cognitive therapies in adults. Because of this, we contend that ABCD project data will be a crucial resource for prevention and treatment of SUD in adolescence because its cutting-edge neuroimaging and childhood assessments hold potential for discovery of additional targetable brain differences earlier in development that are prognostic of (or aberrant in) SUD. The ABCD sample size will also have the power to illuminate how sex differences, environmental interactions and

  17. Multi-cell disk-and-ring tapered structure for compact RF linacs

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, A.V.; Boucher, S.; Kutsaev, S. [RadiaBeam Systems LLC, 1713 Stewart Street, Santa Monica, CA 90404, US (United States); Hartzell, J. [RadiaBeam Technologies, LLC, 1717 Stewart Street, Santa Monica, CA 90404, US (United States); Savin, E. [RadiaBeam Technologies, LLC, 1717 Stewart Street, Santa Monica, CA 90404, US (United States); National Research Nuclear University “MEPhI”, Moscow 115409 (Russian Federation)

    2016-09-11

    A tubular disk-and-ring, tapered accelerating structure for small electron linacs and MicroLinacs is considered. It consists of metal and dielectric elements inserted into a metallic tube to eliminate multi-cell, multi-step brazing. The structure enables a wide range of phase velocities (including non-relativistic), a wide bandwidth allowing large number of cells (for standing wave mode) or short filling time (for traveling wave mode), combination of compensated and purely π-mode cells, alternative periodic focusing built-in to the RF structure (the disks), and combining of RF and vacuum windows. RF and accelerating performance of such a long structure having up to four dozens cells is analyzed. Some of beam dynamics, thermal, and vacuum aspects of the structure and MicroLinac performance are considered as well.

  18. The ABCD and ABCD2 Scores and the Risk of Stroke following a TIA: A Narrative Review.

    Science.gov (United States)

    Bhatt, Archit; Jani, Vishal

    2011-01-01

    The California, ABCD, and ABCD2 risk scores (ABCD system) were developed to help stratify short-term stroke risk in patients with TIA (transient ischemic attack). Beyond this scope, the ABCD system has been extensively used to study other prognostic information such as DWI (diffusion-weighted imaging) abnormalities, large artery stenosis, atrial fibrillation and its diagnostic accuracy in TIA patients, which are independent predictors of subsequent stroke in TIA patients. Our comprehensive paper suggested that all scores have and equivalent prognostic value in predicting short-term risk of stroke; however, the ABCD2 score is being predominantly used at most centers. The majority of studies have shown that more than half of the strokes in the first 90 days, occur in the first 7 days. The majority of patients studied were predominantly classified to have a higher ABCD/ABCD2 > 3 scores and were particularly at a higher short-term risk of stroke or TIA and other vascular events. However, patients with low risk ABCD2 score < 4 may have high-risk prognostic indicators, such as diffusion weighted imaging (DWI) abnormalities, large artery atherosclerosis (LAA), and atrial fibrillation (AF). The prognostic value of these scores improved if used in conjunction with clinical information, vascular imaging data, and brain imaging data. Before more data become available, the diagnostic value of these scores, its applicability in triaging patients, and its use in evaluating long-term prognosis are rather secondary; thus, indicating that the primary significance of these scores is for short-term prognostic purposes.

  19. Katanin spiral and ring structures shed light on power stroke for microtubule severing.

    Science.gov (United States)

    Zehr, Elena; Szyk, Agnieszka; Piszczek, Grzegorz; Szczesna, Ewa; Zuo, Xiaobing; Roll-Mecak, Antonina

    2017-09-01

    Microtubule-severing enzymes katanin, spastin and fidgetin are AAA ATPases important for the biogenesis and maintenance of complex microtubule arrays in axons, spindles and cilia. Because of a lack of known 3D structures for these enzymes, their mechanism of action has remained poorly understood. Here we report the X-ray crystal structure of the monomeric AAA katanin module from Caenorhabditis elegans and cryo-EM reconstructions of the hexamer in two conformations. The structures reveal an unexpected asymmetric arrangement of the AAA domains mediated by structural elements unique to microtubule-severing enzymes and critical for their function. The reconstructions show that katanin cycles between open spiral and closed ring conformations, depending on the ATP occupancy of a gating protomer that tenses or relaxes interprotomer interfaces. Cycling of the hexamer between these conformations would provide the power stroke for microtubule severing.

  20. Mega-rings Surrounding Timber Mountain Nested Calderas, Geophysical Anomalies: Rethinking Structure and Volcanism Near Yucca Mountain (YM), Nevada

    Science.gov (United States)

    Tynan, M. C.; Smith, K. D.; Savino, J. M.; Vogt, T. J.

    2004-12-01

    Observed regional mega-rings define a zone ˜80-100 km in diameter centered on Timber Mountain (TM). The mega-rings encompass known smaller rhyolitic nested Miocene calderas ( ˜11-15 my, calderas cluster within the central area and on the outer margin of the interpreted larger mega-ring complex. The mega-ring interpretation is consistent with observations of regional physiography, tomographic images, seismicity patterns, and structural relationships. Mega-rings consist of arcuate faulted blocks with deformation (some remain active structures) patterns showing a genetic relationship to the TM volcanic system; they appear to be spatially associated and temporally correlated with Miocene volcanism and two geophysically identified crustal/upper mantle features. A 50+ km diameter pipe-like high velocity anomaly extends from crustal depth to over 200 km beneath TM (evidence for 400km depth to NE). The pipe is located between two ˜100 km sub-parallel N/S linear trends of small-magnitude earthquake activity, one extending through the central NV Test Site, and a second located near Beatty, NV. Neither the kinematics nor relational mechanism of 100km seismically active N/S linear zones, pipe, and mega-rings are understood. Interpreted mega-rings are: 1) Similar in size to larger terrestrial volcanic complexes (e.g., Yellowstone, Indonesia's Toba system); 2) Located in the region of structural transition from the Mohave block to the south, N/S Basin and Range features to the north, Walker Lane to the NW, and the Las Vegas Valley shear zone to the SE; 3) Associated with the two seismically active zones (similar to other caldera fault-bounded sags), the mantle high velocity feature, and possibly a regional bouguer gravity anomaly; 4) Nearly coincident with area hydrologic basins and sub-basins; 5) Similar to features described from terrestrial and planetary caldera-collapse studies, and as modeled in laboratory scaled investigations (ice melt, balloon/sand). Post Mid

  1. Molecular cell biology and immunobiology of mammalian rod/ring structures.

    Science.gov (United States)

    Carcamo, Wendy C; Calise, S John; von Mühlen, Carlos A; Satoh, Minoru; Chan, Edward K L

    2014-01-01

    Nucleotide biosynthesis is a highly regulated process necessary for cell growth and replication. Cytoplasmic structures in mammalian cells, provisionally described as rods and rings (RR), were identified by human autoantibodies and recently shown to include two key enzymes of the CTP/GTP biosynthetic pathways, cytidine triphosphate synthetase (CTPS) and inosine monophosphate dehydrogenase (IMPDH). Several studies have described CTPS filaments in mammalian cells, Drosophila, yeast, and bacteria. Other studies have identified IMPDH filaments in mammalian cells. Similarities among these studies point to a common evolutionarily conserved cytoplasmic structure composed of a subset of nucleotide biosynthetic enzymes. These structures appear to be a conserved metabolic response to decreased intracellular GTP and/or CTP pools. Antibodies to RR were found to develop in some hepatitis C patients treated with interferon-α and ribavirin. Additionally, the presence of anti-RR antibodies was correlated with poor treatment outcome. © 2014 Elsevier Inc. All rights reserved.

  2. Katanin spiral and ring structures shed light on power stroke for microtubule severing

    Energy Technology Data Exchange (ETDEWEB)

    Zehr, Elena; Szyk, Agnieszka; Piszczek, Grzegorz; Szczesna, Ewa; Zuo, Xiaobing; Roll-Mecak, Antonina

    2017-08-07

    Microtubule-severing enzymes katanin, spastin and fidgetin are AAA ATPases critical for the biogenesis and maintenance of complex microtubule arrays in axons, spindles and cilia. Because of a lack of 3D structures, their mechanism has remained poorly understood. We report the first X-ray structure of the monomeric AAA katanin module and cryo-EM reconstructions of the hexamer in two conformations. These reveal an unexpected asymmetric arrangement of the AAA domains mediated by structural elements unique to severing enzymes and critical for their function. Our reconstructions show that katanin cycles between open spiral and closed ring conformations, depending on the ATP occupancy of a gating protomer that tenses or relaxes inter-protomer interfaces. Cycling of the hexamer between these conformations would provide the power stroke for microtubule severing.

  3. Radical theory of rings

    CERN Document Server

    Gardner, JW

    2003-01-01

    Radical Theory of Rings distills the most noteworthy present-day theoretical topics, gives a unified account of the classical structure theorems for rings, and deepens understanding of key aspects of ring theory via ring and radical constructions. Assimilating radical theory's evolution in the decades since the last major work on rings and radicals was published, the authors deal with some distinctive features of the radical theory of nonassociative rings, associative rings with involution, and near-rings. Written in clear algebraic terms by globally acknowledged authorities, the presentation

  4. Voyager radio occultation by the Uranian rings: Structure, dynamics, and particle sizes. Ph.D. Thesis Final Technical Report

    Science.gov (United States)

    Gresh, Donna Leigh

    1990-01-01

    Diffraction of Voyager 2's 3.6 and 13 cm wavelength microwaves by the Uranian rings is removed through an inverse Fresnel transform filtering procedure that accommodates the significant eccentricity of the rings. Resulting 50 m resolution profiles at two observation longitudes: (1) reveal remarkably detailed and longitudinally varying structure, (2) provide eccentricity gradient profiles of Rings alpha, beta, and epsilon which bring into question current theoretical models for observed rigid precession, and (3) suggest that two possible unseen satellites may confine some of the very sharp edges observed via resonant interactions.

  5. ATLAS ABCD Hybrid Fatal Charge Dosage Test

    CERN Document Server

    Kuhl, A; The ATLAS collaboration; Grillo, AA; Martinez-McKinney, F; Nielsen, J; Spencer, E; Wilder, M

    2011-01-01

    The Semi-Conductor Tracker (SCT) in the ATLAS experiment at the Large Hadron Collider (LHC) could be subject to various beam loss scenarios. If a severe beam loss event were to occur, it would be beneficial to know how SCT components would be affected. In the SCT detector modules, a key component is the ABCD application specific integrated circuit (ASIC), the onboard readout electronics of the system. This ASIC has design specifications that it should withstand a 5nC charge injection within 25 ns, which is the period of the LHC bunch crossing. The first test performed is designed to test this limit, reaching a maximum of 10nC deposited in 25 ns. One model for beam loss predicts that a large charge, of the order of 10^6 MIPS, could be incident on the detector. According to detector studies, this causes a local field breakdown between the backplane of the sensor, held at 450V, and the strips. In this case the signal seen on the readout strip has a rise time of about 1μs due to a charge screening effect. A seco...

  6. ATLAS ABCD Hybrid Fatal Charge Dosage Test

    CERN Document Server

    Kuhl, A; Grillo, A A; Martinez-McKinney, F; Nielsen, J; Spencer, E; Wilder, M

    2011-01-01

    The Semi-Conductor Tracker (SCT) in the ATLAS experiment at the Large Hadron Collider (LHC) could be subject to various beam loss scenarios. If a severe beam loss event were to occur, it would be beneficial to know how SCT components would be affected. In the SCT detector modules, a key component is the ABCD application specific integrated circuit (ASIC), the onboard readout electronics of the system. This ASIC has design specifications that it should withstand a 5 nC charge application within 25 ns, which is the period of the LHC bunch crossing. The first test performed is designed to test this limit, reaching a maximum of 10 nC deposited in 25 ns. One model for beam loss predicts that a large charge, of the order of 106 MIPS, could be incident on the detector. According to detector studies, this causes a local field breakdown between the backplane of the sensor, held at 450 V, and the strips. In this case the signal seen on the readout strip has a rise time of about 1 μs due to a charge screening effect. A...

  7. ABC Transporter Subfamily D: Distinct Differences in Behavior between ABCD1–3 and ABCD4 in Subcellular Localization, Function, and Human Disease

    Directory of Open Access Journals (Sweden)

    Kosuke Kawaguchi

    2016-01-01

    Full Text Available ATP-binding cassette (ABC transporters are one of the largest families of membrane-bound proteins and transport a wide variety of substrates across both extra- and intracellular membranes. They play a critical role in maintaining cellular homeostasis. To date, four ABC transporters belonging to subfamily D have been identified. ABCD1–3 and ABCD4 are localized to peroxisomes and lysosomes, respectively. ABCD1 and ABCD2 are involved in the transport of long and very long chain fatty acids (VLCFA or their CoA-derivatives into peroxisomes with different substrate specificities, while ABCD3 is involved in the transport of branched chain acyl-CoA into peroxisomes. On the other hand, ABCD4 is deduced to take part in the transport of vitamin B12 from lysosomes into the cytosol. It is well known that the dysfunction of ABCD1 results in X-linked adrenoleukodystrophy, a severe neurodegenerative disease. Recently, it is reported that ABCD3 and ABCD4 are responsible for hepatosplenomegaly and vitamin B12 deficiency, respectively. In this review, the targeting mechanism and physiological functions of the ABCD transporters are summarized along with the related disease.

  8. ABC Transporter Subfamily D: Distinct Differences in Behavior between ABCD1–3 and ABCD4 in Subcellular Localization, Function, and Human Disease

    Science.gov (United States)

    2016-01-01

    ATP-binding cassette (ABC) transporters are one of the largest families of membrane-bound proteins and transport a wide variety of substrates across both extra- and intracellular membranes. They play a critical role in maintaining cellular homeostasis. To date, four ABC transporters belonging to subfamily D have been identified. ABCD1–3 and ABCD4 are localized to peroxisomes and lysosomes, respectively. ABCD1 and ABCD2 are involved in the transport of long and very long chain fatty acids (VLCFA) or their CoA-derivatives into peroxisomes with different substrate specificities, while ABCD3 is involved in the transport of branched chain acyl-CoA into peroxisomes. On the other hand, ABCD4 is deduced to take part in the transport of vitamin B12 from lysosomes into the cytosol. It is well known that the dysfunction of ABCD1 results in X-linked adrenoleukodystrophy, a severe neurodegenerative disease. Recently, it is reported that ABCD3 and ABCD4 are responsible for hepatosplenomegaly and vitamin B12 deficiency, respectively. In this review, the targeting mechanism and physiological functions of the ABCD transporters are summarized along with the related disease. PMID:27766264

  9. Effect of boundary conditions on magnetocapacitance effect in a ring-type magnetoelectric structure

    Science.gov (United States)

    Zhang, Juanjuan

    2017-12-01

    By considering the nonlinear magneto-elastic coupling relationships of magnetostrictive materials, an analytical model is proposed. The resonance frequencies can be accurately predicted by this theoretical model, and they are in good agreement with experimental data. Subsequently, the magnetocapacitance effect in a ring-type magnetoelectric (ME) structure with different boundary conditions is investigated, and it is found that various mechanical boundaries, the frequency, the magnetic field, the geometric size, and the interface bonding significantly affect the capacitance of the ME structure. Further, additional resonance frequencies can be predicted by considering appropriate imperfect interface bonding. Finally, the influence of an external force on the capacitance is studied. The result shows that an external force on the boundary changes the capacitance, but has only a weak influence on the resonance frequency.

  10. Ring extension of entire ring with conjugation; arithmetic in entire rings

    OpenAIRE

    Laugier, Alexandre

    2013-01-01

    Some basic properties of the ring of integers $\\mathbb{Z}$ are extended to entire rings. In particular, arithmetic in entire principal rings is very similar than arithmetic in the ring of integers $\\mathbb{Z}$. These arithmetic properties are derived from a $\\star$-ring extension of the considered entire ring (ring extension with conjugation) equipped with a real function which is a multiplicative structure-preserving map between two algebras. The algebra of this ring extension is studied in ...

  11. Determinantal rings

    CERN Document Server

    Bruns, Winfried

    1988-01-01

    Determinantal rings and varieties have been a central topic of commutative algebra and algebraic geometry. Their study has attracted many prominent researchers and has motivated the creation of theories which may now be considered part of general commutative ring theory. The book gives a first coherent treatment of the structure of determinantal rings. The main approach is via the theory of algebras with straightening law. This approach suggest (and is simplified by) the simultaneous treatment of the Schubert subvarieties of Grassmannian. Other methods have not been neglected, however. Principal radical systems are discussed in detail, and one section is devoted to each of invariant and representation theory. While the book is primarily a research monograph, it serves also as a reference source and the reader requires only the basics of commutative algebra together with some supplementary material found in the appendix. The text may be useful for seminars following a course in commutative ring theory since a ...

  12. Review: The lord of the rings: Structure and mechanism of the sliding clamp loader.

    Science.gov (United States)

    Kelch, Brian A

    2016-08-01

    Sliding clamps are ring-shaped polymerase processivity factors that act as master regulators of cellular replication by coordinating multiple functions on DNA to ensure faithful transmission of genetic and epigenetic information. Dedicated AAA+ ATPase machines called clamp loaders actively place clamps on DNA, thereby governing clamp function by controlling when and where clamps are used. Clamp loaders are also important model systems for understanding the basic principles of AAA+ mechanism and function. After nearly 30 years of study, the ATP-dependent mechanism of opening and loading of clamps is now becoming clear. Here I review the structural and mechanistic aspects of the clamp loading process, as well as comment on questions that will be addressed by future studies. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 532-546, 2016. © 2016 Wiley Periodicals, Inc.

  13. Memory properties of Ge quantum dots and rings MOS structure prepared by pulsed laser deposition

    Science.gov (United States)

    Ma, Xiying

    2009-03-01

    New memory structures using threshold shifting from charge stored in quantum dots (QDs) and quantum rings (QRs) of Germanium (Ge) are described. The QDs and QRs of Ge were prepared on a p-Si (100) matrix by means of pulsed laser deposition (PLD) using the droplet technique combined with rapid annealing. The perfect planar nanorings with well-defined sharp inner and outer edges were formed via an elastic self-transformation of droplet process, which is probably driven by the lateral strain of the Ge/Si layers under annealing treatment. A significant shift of threshold-voltage of 1.2V and 2.5 V were observed in Ge QDs and QRs memory devices, respectively, when an operating voltage of 8 V was implemented on the device. It is attributed to the effect of Coulomb blockade and better interface properties of the Ge nanostructures.

  14. Body-insensitive Multi-Mode MIMO Terminal Antenna of Double-Ring Structure

    DEFF Research Database (Denmark)

    Zhao, Kun; Zhang, Shuai; Ishimiya, Katsunori

    2015-01-01

    of mobile terminals. With the multimode excitation, the MIMO cellular antenna can operate at 830-900 MHz, 1700-2200 MHz, and 2400-2700 MHz, for 2G, 3G, and LTE bands, respectively. The MIMO Wi-Fi antenna can cover two Wi-Fi bands from 2.4 to 2.5 GHz and from 5.2 to 5.8 GHz. The effect of a user's body......In this paper, we propose a novel multimode multi-input multi-output (MIMO) antenna system composed of a dual-element MIMO cellular antenna and dual-element MIMO Wi-Fi antenna for mobile terminal applications. The antenna system has a double-ring structure and can be integrated with the metal frame...

  15. Structure and origin of Australian ring and dome features with reference to the search for asteroid impact events

    Science.gov (United States)

    Glikson, Andrew

    2018-01-01

    Ring, dome and crater features on the Australian continent and shelf include (A) 38 structures of confirmed or probable asteroid and meteorite impact origin and (B) numerous buried and exposed ring, dome and crater features of undefined origin. A large number of the latter include structural and geophysical elements consistent with impact structures, pending test by field investigations and/or drilling. This paper documents and briefly describes 43 ring and dome features with the aim of appraising their similarities and differences from those of impact structures. Discrimination between impact structures and igneous plugs, volcanic caldera and salt domes require field work and/or drilling. Where crater-like morphological patterns intersect pre-existing linear structural features and contain central morphological highs and unique thrust and fault patterns an impact connection needs to tested in the field. Hints of potential buried impact structures may be furnished by single or multi-ring TMI patterns, circular TMI quiet zones, corresponding gravity patterns, low velocity and non-reflective seismic zones.

  16. The ABCD and ABCD2 as predictors of stroke in transient ischemic attack clinic outpatients: a retrospective cohort study over 14 years.

    Science.gov (United States)

    Harrison, J K; Sloan, B; Dawson, J; Lees, K R; Morrison, D S

    2010-09-01

    The ABCD and ABCD2 scores have been validated for use as predictors of stroke in community populations up to 90 days after a transient ischemic attack (TIA). TIA outpatient clinics may see a selective group of patients who have not had an early stroke but may be at raised risk in the medium to long term and therefore benefit from preventive treatment. To describe the prognostic values of the ABCD and ABCD2 scores on long-term stroke risk. Retrospective cohort study of TIA clinic outpatients followed for up to 14 years. Absolute and relative stroke risks, Kaplan-Meier survival curves and cumulative stroke incidence were calculated. Receiver Operating Characteristic curves (ROCs) and areas under the curve were calculated for both scores. Seven hundred and ninety-five patients were included and 138 (17.3%) experienced a stroke within 13.8 years follow-up after first TIA clinic visit, a crude risk of 26.3 per 1000 person-years. Compared with baseline scores of 0-2, risk ratios for ABCD of 3-4 were 2.95 (95% CI 1.52-6.40), and for 5-6 were 3.42 (95% CI 1.72-7.54); for the ABCD2, risk ratios for 3-4 were 2.68 (95% CI 1.37-5.84), and for 5-7 were 3.55 (95% CI 1.80-7.79). Scores of > or = 3 for either ABCD or ABCD2 predicted raised stroke risks at 90 days, 1, 5 and 10 years. Areas under the curve were 0.619 (95% CI 0.571-0.668) and 0.630 (95% CI 0.582-0.677) for the ABCD and ABCD2 scores, respectively. ABCD and ABCD2 scores of > or = 3 may be clinically useful in identifying TIA outpatients at raised risk of stroke in the medium to long term.

  17. Alternative loop rings

    CERN Document Server

    Goodaire, EG; Polcino Milies, C

    1996-01-01

    For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

  18. Morphology of symmetric ABCD tetrablock quaterpolymers studied by Monte Carlo simulation

    Science.gov (United States)

    Suzuki, Jiro; Takano, Atsushi; Matsushita, Yushu

    2016-11-01

    Morphology of symmetric ABCD tetrablock quaterpolymers in melt was studied by the Monte Carlo (MC) simulation, where the volume fractions of the block chains, f, kept the relationships of fA=fD and fB=fC , and the volume fraction of the two mid-blocks φ was defined as φ =fB+fC . Previous self-consistent field theory for ABCD reported morphological change including several structures; however, the scope was limited within a two-dimensional system. To the contrary, in this paper, MC simulations were carried out in three dimensions with changing the φ value finely, which resulted in finding a tetracontinuous structure in the range of 0.625 ≤φ ≤0.75 . Moreover the tetracontinuous structure has been found to be the gyroid structure, and the mean curvature of the B/C interface is nearly zero. We concluded that the B/C interface must be the Schoen gyroid surface, one of three-dimensional periodic minimal surfaces. The geometrical nature of the A/B interface should be equivalent to that of the C/D interface, and they stand as level surfaces to the Schoen gyroid surface.

  19. The Legal Structure of Ring-Fenced Bodies in the United Kingdom - A Response to Consultation Paper CP19/14 on the Implementation of Ring-fencing: on Legal Structure, Governance and the continuity of Services and Facilities

    NARCIS (Netherlands)

    K. Heine (Klaus); V.L.E. Cedeno-Brea (Enmanuel)

    2015-01-01

    markdownabstract__Abstract__ This paper is submitted by Prof. Dr. Klaus Heine1 and Enmanuel Cedeño-Brea2, in response to the Prudential Regulatory Authority’s (PRA) Consultation Paper CP19/14 on “The Implementation of Ring-fencing: consultation on legal structure, governance and the continuity of

  20. Structure reliability design and analysis of support ring for cylinder seal

    Science.gov (United States)

    Minmin, Zhao

    2017-09-01

    In this paper, the general reliability design process of the cross-sectional dimension of the support ring is introduced, which is used for the cylinder sealing. Then, taking a certain section shape support ring as an example, the every size parameters of section are determined from the view point of reliability design. Last, the static strength and reliability of the support ring are analyzed to verify the correctness of the reliability design result.

  1. Characterization of ring-like F-actin structure as a mechanical partner for spindle positioning in mitosis.

    Directory of Open Access Journals (Sweden)

    Huan Lu

    Full Text Available Proper spindle positioning and orientation are essential for accurate mitosis which requires dynamic interactions between microtubule and actin filament (F-actin. Although mounting evidence demonstrates the role of F-actin in cortical cytoskeleton dynamics, it remains elusive as to the structure and function of F-actin-based networks in spindle geometry. Here we showed a ring-like F-actin structure surrounding the mitotic spindle which forms since metaphase and maintains in MG132-arrested metaphase HeLa cells. This cytoplasmic F-actin structure is relatively isotropic and less dynamic. Our computational modeling of spindle position process suggests a possible mechanism by which the ring-like F-actin structure can regulate astral microtubule dynamics and thus mitotic spindle orientation. We further demonstrated that inhibiting Plk1, Mps1 or Myosin, and disruption of microtubules or F-actin polymerization perturbs the formation of the ring-like F-actin structure and alters spindle position and symmetric division. These findings reveal a previously unrecognized but important link between mitotic spindle and ring-like F-actin network in accurate mitosis and enables the development of a method to theoretically illustrate the relationship between mitotic spindle and cytoplasmic F-actin.

  2. ABCD1 dysfunction alters white matter microvascular perfusion

    DEFF Research Database (Denmark)

    Lauer, Arne; Da, Xiao; Hansen, Mikkel Bo

    2017-01-01

    Cerebral X-linked adrenoleukodystrophy is a devastating neurodegenerative disorder caused by mutations in the ABCD1 gene, which lead to a rapidly progressive cerebral inflammatory demyelination in up to 60% of affected males. Selective brain endothelial dysfunction and increased permeability...

  3. Open Source Solutions for Libraries: ABCD vs Koha

    Science.gov (United States)

    Macan, Bojan; Fernandez, Gladys Vanesa; Stojanovski, Jadranka

    2013-01-01

    Purpose: The purpose of this study is to present an overview of the two open source (OS) integrated library systems (ILS)--Koha and ABCD (ISIS family), to compare their "next-generation library catalog" functionalities, and to give comparison of other important features available through ILS modules. Design/methodology/approach: Two open source…

  4. East Indian Families Raising ABCD Adolescents: Cultural and Generational Challenges

    Science.gov (United States)

    Poulsen, Shruti S.

    2009-01-01

    Immigration is a process fraught with both challenges and opportunities for families. In particular, East Indian families with U.S.-born adolescents experience the challenges of bridging cultures across generational divides; they are perceived by others as confused, identity less, and conflicted or as American-Born, Confused Desis (ABCDs). This…

  5. Character Development in Education: The ABCD's of Valuing.

    Science.gov (United States)

    Tomaselli, Joseph M.; Golden, John P.

    1996-01-01

    Describes an innovative values education program at a suburban New Jersey high school. The ABCD program's premise is that teachers and students must know themselves before they can benefit from a school's educational and teaching experiences. The pilot project, which emphasized self-awareness training, showed that ninth graders could understand…

  6. Administration's Overview: K-12 Physical Education. ABCD's of Physical Education.

    Science.gov (United States)

    Alberta Learning, Edmonton.

    In September 2000, the Physical Education Kindergarten to Grade 12 Program of Studies was approved for implementation in Alberta, Canada. This program helps enable individuals to develop the knowledge, skills, and attitudes necessary to lead an active, healthy lifestyle. The four general outcomes are the ABCDs (Activity, Benefits Health,…

  7. Complex-Valued ABCD Matrices and Speckle Metrology

    DEFF Research Database (Denmark)

    Hanson, Steen Grüner; Jakobsen, Michael Linde; Yura, Harold T.

    2016-01-01

    We demonstrate that within the paraxial ray approximation the propagation of light through a complex optical system can be formulated in terms of a Huygens principle expressed with the complete system’s ABCD-matrix elements. As such, propagation through an optical system reduces to that of calcul...

  8. Ring Theory

    CERN Document Server

    Jara, Pascual; Torrecillas, Blas

    1988-01-01

    The papers in this proceedings volume are selected research papers in different areas of ring theory, including graded rings, differential operator rings, K-theory of noetherian rings, torsion theory, regular rings, cohomology of algebras, local cohomology of noncommutative rings. The book will be important for mathematicians active in research in ring theory.

  9. Nerve ring of the hypostome in hydra. I. Its structure, development, and maintenance

    DEFF Research Database (Denmark)

    Koizumi, O; Itazawa, M; Mizumoto, H

    1992-01-01

    The anatomy and developmental dynamics of the nerve ring in the hypostome of Hydra oligactis were examined immunocytochemically with an antiserum against a neuropeptide and with neuron-specific monoclonal antibodies. The nerve ring is unique in the mesh-like nerve net of hydra. It is a distinct...... appeared only after the nerve net of ganglion and sensory cells had formed. Every epithelial cell is continuously displaced with neurons toward either head or foot in an adult hydra. However, the ectoderm in the immediate vicinity of, and including, the nerve ring constitutes a stationary zone...... ring is static and stable in contrast to the dynamic features of the nerve net of hydra....

  10. Propagation of a partially coherent hollow vortex Gaussian beam through a paraxial ABCD optical system in turbulent atmosphere.

    Science.gov (United States)

    Zhou, Guoquan; Cai, Yangjian; Chu, Xiuxiang

    2012-04-23

    The propagation of a partially coherent hollow vortex Gaussian beam through a paraxial ABCD optical system in turbulent atmosphere has been investigated. The analytical expressions for the average intensity and the degree of the polarization of a partially coherent hollow vortex Gaussian beam through a paraxial ABCD optical system are derived in turbulent atmosphere, respectively. The average intensity distribution and the degree of the polarization of a partially coherent hollow vortex Gaussian beam in turbulent atmosphere are numerically demonstrated. The influences of the beam parameters, the topological charge, the transverse coherent lengths, and the structure constant of the atmospheric turbulence on the propagation of a partially coherent hollow vortex Gaussian beam in turbulent atmosphere are also examined in detail. This research is beneficial to the practical applications in free-space optical communications and the remote sensing of the dark hollow beams. © 2012 Optical Society of America

  11. Tests of a niobium split-ring superconducting heavy ion accelerating structure

    Energy Technology Data Exchange (ETDEWEB)

    Benaroya, R.; Bollinger, L.M.; Jaffey, A.H.; Khoe, T.K.; Olesen, M.C.; Scheibelhut, C.H.; Shepard, K.W.; Wesolowski, W.A.

    1976-01-01

    A niobium split-ring accelerating structure designed for use in the Argonne superconducting heavy-ion energy booster was successfully tested. The superconducting resonator has a resonant frequency of 97 MHz and an optimum particle velocity ..beta.. = 0.11. Ultimate performance is expected to be limited by peak surface fields, which in this structure are 4.7 E/sub a/ electric and 170 E/sub a/ (Gauss) magnetic, where E/sub a/ is the effective accelerating gradient in MV/m. The rf losses in two demountable superconducting joints severely limited performance in initial tests. Following independent measurements of the rf loss properties of several types of demountable joints, one demountable joint was eliminated and the other modified. Subsequently, the resonator could be operated continuously at E/sub a/ = 3.6 MV/m (corresponding to an energy gain of 1.3 MeV per charge) with 10W rf input power. Maximum field level was limited by electron loading. The mechanical stability of the resonator under operating conditions is excellent: vibration induced eigenfrequency noise is less than 120 Hz peak to peak, and the radiation pressure induced frequency shift is ..delta..f/f = 1.6 x 10/sup -6/ E/sub a//sup 2/.

  12. Influence of chemical structure on hypersensitivity reactions induced by antiepileptic drugs: the role of the aromatic ring.

    NARCIS (Netherlands)

    Handoko, K.B.; Puijenbroek, E.P. van; Bijl, A.H.; Hermens, W.A.; Rijkom, JE Zwart-van; Hekster, Y.A.; Egberts, T.C.G.

    2008-01-01

    OBJECTIVE: Antiepileptic drugs (AEDs) can cause various 'idiosyncratic' hypersensitivity reactions, i.e. the mechanism by which AEDs induce hypersensitivity is unknown. The aim of this study was to assess whether the presence of an aromatic ring as a commonality in chemical structures of AEDs can

  13. Influence of chemical structure on hypersensitivity reactions induced by antiepileptic drugs : the role of the aromatic ring

    NARCIS (Netherlands)

    Handoko, Kim B; van Puijenbroek, Eugène P; Bijl, Annemarie H; Hermens, Walter A J J; Zwart-van Rijkom, Jeannette E F; Hekster, Yechiel A; Egberts, Toine C G

    2008-01-01

    OBJECTIVE: Antiepileptic drugs (AEDs) can cause various 'idiosyncratic' hypersensitivity reactions, i.e. the mechanism by which AEDs induce hypersensitivity is unknown. The aim of this study was to assess whether the presence of an aromatic ring as a commonality in chemical structures of AEDs can

  14. Beckmann rearrangement within the ring C of oleanolic acid lactone: Synthesis, structural study and reaction mechanism analysis

    Science.gov (United States)

    Froelich, Anna; Bednarczyk-Cwynar, Barbara; Zaprutko, Lucjusz; Gzella, Andrzej

    2017-05-01

    Synthesis, spectral and X-ray analysis of three compounds, i.e. 3β-acetoxy-12-hydroxyimino-18β-oleanan-28,13β-olide (substrate) and 3β-acetoxy-12-nitrile-12,13-seco-15(14 → 13)-abeoolean-14(27)-en-28,13β-olide and 3β-acetoxy-12-oxo-12a-aza-C-homoolean-13(18)-en-28-oic acid (Beckmann rearrangement reaction products) are described. Structural analysis revealed that the oxime group in the ring C in substrate molecule had an E-configuration. The nitrile product with retained lactone group was a result of major transformations within rings C and D of oleanane skeleton. In lactam product free carboxyl group and a double bond in ring D instead of lactone system were formed in Beckmann rearrangement reaction.

  15. Erbium-doped fiber ring laser based on few-mode-singlemode-few-mode fiber structure for refractive index measurement

    Science.gov (United States)

    Liu, Jingxuan; Wang, Muguang; Liang, Xiao; Dong, Yue; Xiao, Han; Jian, Shuisheng

    2017-08-01

    A novel Erbium-doped fiber ring cavity laser sensor for refractive index (RI) measurement based on a special designed few-mode-singlemode-few-mode structure is proposed and experimentally demonstrated. The few-mode fiber is a home-made concentric ring core fiber (CRCF) which can only support two scalar modes. Thus a stable mode interference occurs which functions as a sensing head and band-pass filter to select the lasing wavelength simultaneously. A sensitivity of -45.429 nm/RIU is obtained in the range of 1.333-1.363. High optical signal to noise ratio (OSNR) of ∼45 dB and narrow 3-dB bandwidth of ∼0.1 nm indicate that the fiber ring laser sensing system has a high resolution and accuracy RI measurement.

  16. Design, synthesis and structure-activity relationships studies on the D ring of the natural product triptolide.

    Science.gov (United States)

    Xu, Hongtao; Tang, Huanyu; Feng, Huijin; Li, Yuanchao

    2014-02-01

    Triptolide is a diterpene triepoxide natural product isolated from Tripterygium wilfordii Hook F, a traditional Chinese medicinal herb. Triptolide has previously been shown to possess antitumor, anti-inflammatory, immunosuppressive, and antifertility activities. Earlier reports suggested that the five-membered unsaturated lactone ring (D ring) is essential for potent cytotoxicity, however, to the best of our knowledge, systematic structure-activity relationship studies have not yet been reported. Here, four types of D ring-modified triptolide analogues were designed, synthesized and evaluated against human ovarian (SKOV-3) and prostate (PC-3) carcinoma cell lines. The results suggest that the D ring is essential to potency, however it can be modified, for example to C18 hydrogen bond acceptor and/or donor furan ring analogues, without complete loss of cytotoxic activity. Interestingly, evaluation of the key series of C19 analogues showed that this site is exquisitely sensitive to polarity. Together, these results will guide further optimization of this natural product lead compound for the development of potent and potentially clinically useful triptolide analogues. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Radical aryl migration enables diversity-oriented synthesis of structurally diverse medium/macro- or bridged-rings

    Science.gov (United States)

    Li, Lei; Li, Zhong-Liang; Wang, Fu-Li; Guo, Zhen; Cheng, Yong-Feng; Wang, Na; Dong, Xiao-Wu; Fang, Chao; Liu, Jingjiang; Hou, Chunhui; Tan, Bin; Liu, Xin-Yuan

    2016-12-01

    Medium-sized and medium-bridged rings are attractive structural motifs in natural products and therapeutic agents. Due to the unfavourable entropic and/or enthalpic factors with these ring systems, their efficient construction remains a formidable challenge. To address this problem, we herein disclose a radical-based approach for diversity-oriented synthesis of various benzannulated carbon- and heteroatom-containing 8-11(14)-membered ketone libraries. This strategy involves 1,4- or 1,5-aryl migration triggered by radical azidation, trifluoromethylation, phosphonylation, sulfonylation, or perfluoroalkylation of unactivated alkenes followed by intramolecular ring expansion. Demonstration of this method as a highly flexible tool for the construction of 37 synthetically challenging medium-sized and macrocyclic ring scaffolds including bridged rings with diverse functionalities and skeletons is highlighted. Some of these products showed potent inhibitory activity against the cancer cell or derivative of human embryonic kidney line in preliminary biological studies. The mechanism of this novel strategy is investigated by control experiments and DFT calculations.

  18. Systematic review and pooled analysis of published and unpublished validations of the ABCD and ABCD2 transient ischemic attack risk scores.

    Science.gov (United States)

    Giles, Matthew F; Rothwell, Peter M

    2010-04-01

    The ABCD system was derived to predict early risk of stroke after transient ischemic attack. Independent validations have reported conflicting results. We therefore systematically reviewed published and unpublished data to determine predictive value and generalizability to different clinical settings and users. Validations of the ABCD and ABCD2 scores were identified by searching electronic databases, reference lists, relevant journals, and conference abstracts. Unpublished tabulated data were obtained where available. Predictive value, expressed as pooled areas under the receiver operator characteristic curves (AUC), was calculated using random-effects meta-analysis, and analyses for heterogeneity were performed by categorization according to study setting and method. Twenty cohorts were identified reporting the performance of the ABCD system in 9808 subjects with 456 strokes at 7 days. Among the 16 studies of both the ABCD and ABCD2 scores, pooled AUC for the prediction of stroke at 7 days were 0.72 (0.66 to 0.78) and 0.72 (0.63 to 0.82), respectively (P diff=0.97). The pooled AUC for the ABCD and ABCD2 scores in all cohorts reporting relevant data were 0.72 (0.67 to 0.77) and 0.72 (0.63 to 0.80), respectively (both PABCD system showed good predictive value, with the exception of studies based on retrospective extraction of nonsystematically collected data from emergency department records.

  19. Fused-ring structure of decahydroisoquinolin as a novel scaffold for SARS 3CL protease inhibitors.

    Science.gov (United States)

    Shimamoto, Yasuhiro; Hattori, Yasunao; Kobayashi, Kazuya; Teruya, Kenta; Sanjoh, Akira; Nakagawa, Atsushi; Yamashita, Eiki; Akaji, Kenichi

    2015-02-15

    The design and evaluation of a novel decahydroisoquinolin scaffold as an inhibitor for severe acute respiratory syndrome (SARS) chymotrypsin-like protease (3CL(pro)) are described. Focusing on hydrophobic interactions at the S2 site, the decahydroisoquinolin scaffold was designed by connecting the P2 site cyclohexyl group of the substrate-based inhibitor to the main-chain at the α-nitrogen atom of the P2 position via a methylene linker. Starting from a cyclohexene enantiomer obtained by salt resolution, trans-decahydroisoquinolin derivatives were synthesized. All decahydroisoquinolin inhibitors synthesized showed moderate but clear inhibitory activities for SARS 3CL(pro), which confirmed the fused ring structure of the decahydroisoquinolin functions as a novel scaffold for SARS 3CL(pro) inhibitor. X-ray crystallographic analyses of the SARS 3CL(pro) in a complex with the decahydroisoquinolin inhibitor revealed the expected interactions at the S1 and S2 sites, as well as additional interactions at the N-substituent of the inhibitor. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. First annular-ring coupled structure cavity for the Japan Proton Accelerator Research Complex linac

    Directory of Open Access Journals (Sweden)

    Hiroyuki Ao

    2012-05-01

    Full Text Available The first annular-ring coupled structure (ACS cavity for the Japan Proton Accelerator Research Complex (J-PARC linac has been developed in order to confirm and establish its fabrication processes. This cavity includes 34 accelerating cells, which is 3.4 times as many as the prototype cavity (buncher of the J-PARC ACS. The cell frequencies before brazing were tuned within the required accuracies. After brazing, the accelerating- and coupling-mode frequencies were 972.19 and 972.63 MHz on average, respectively, which were higher than the operating frequency of 972 MHz. Although the accelerating-mode frequency can be corrected to 972 MHz using adjustable plungers, these frequency errors adversely affected the on-axis electric field. This cavity was successfully conditioned up to 1.6 MW. This power corresponds to an accelerating field of 4.7  MV/m, which is 10% higher than the design value of 4.2  MV/m. In order to find the issue caused by the excited coupling cells, this cavity was also conditioned at the higher and lower frequencies that were detuned from the operating frequency of 972 MHz. Here we present the frequency tuning processes, the low-level rf measurements, and the high-power test results. We also discuss the most reasonable scenario for frequency tuning in future work.

  1. Evaluation of a multi-guard ring (MGR) structure diode as diagnostic X-ray dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, F. [Instituto de Pesquisas Energeticas e Nucleares IPEN-CNEN/SP, Caixa Postal 11049, Sao Paulo SP 05422-970, Brasil (Brazil); Khoury, H.J.; Nascimento, C.R.; Asfora, V.K. [Universidade Federal de Pernambuco, Av. Prof. Luiz Freire 1000, Recife PE 50740-540, Brasil (Brazil); Bueno, C.C. [Instituto de Pesquisas Energeticas e Nucleares IPEN-CNEN/SP, Caixa Postal 11049, Sao Paulo SP 05422-970, Brasil (Brazil); Pontificia Universidade Catolica de Sao Paulo, Rua Marques de Paranagua 111, Sao Paulo SP 01303-050, Brasil (Brazil)], E-mail: ccbueno@ipen.br

    2007-09-21

    In this paper, we describe the results obtained for the evaluation of a multi-guard ring (MGR) structure diode as diagnostic X-ray dosimeter. This device was developed in the framework of R and D programs for the future CMS experiment at the Large Hadron Collider (LHC) with high radiation hardness to fulfill the requirements from this accelerator environment. In order to use the MGR diode as a dosimeter, it was connected in the photovoltaic mode to the input of an integrating electrometer and positioned at the center of an X-ray beam, beside a previously calibrated ionization chamber. The dependence of the diode response on the X-ray beam doses was evaluated for 35-90 kV X-ray generator bias supply, with doses in the range of 50 {mu}Gy-5 mGy. The good linearity of the dose-response curve obtained showed the MGR diode dosimeter to be a reliable alternative method for diagnostic X-ray dosimetry.

  2. Formation mechanism for the structure of the magnetic-storm ring current

    CERN Document Server

    Tverskoy, B A

    1999-01-01

    An analysis is presented for the implications of the relationship between the amplitude of the Dst variation and the position L sub m sub a sub x of the intensity maximum of the relativistic-electron belt that arises immediately after the cessation of a storm. The quantity L sub m sub a sub x is regarded to correspond to the position of the pressure maximum of the ring-current plasma at the moment of the maximum amplitude of the storm main phase. Under this assumption, the structure of the mentioned plasma formation is calculated, and the idea is substantiated that the plasma cloud is adiabatically driven deep into the magnetosphere during the sub-storm and subsequently symmetrized (this idea was originally put forward by the author on the basis of the theory of the magnetosphere-ionosphere interaction). It is shown that the presence of the mentioned relationship implies the existence of a certain boundary where the entropy calculated for a unit-magnetic-flux tube always has the same value. The applicability ...

  3. Geology, structure, and statistics of multi-ring basins on Mars

    Science.gov (United States)

    Schultz, Richard A.; Frey, Herbert V.

    1990-01-01

    Available data on Martian multi-ring basins were compiled and evaluated using the new 1:15 million scale geologic maps of Mars and global topography was revised as base maps. Published center coordinates and ring diameters of Martian basins were plotted by computer and superimposed onto the base maps. In many cases basin centers or ring diameters or both had to be adjusted to achieve a better fit to the revised maps. It was also found that additional basins can explain subcircular topographic lows as well as map patterns of old Noachian materials, volcanic plains units, and channels in the Tharsis region.

  4. Regulation of the adrenoleukodystrophy-related gene (ABCD2): focus on oxysterols and LXR antagonists.

    Science.gov (United States)

    Trompier, Doriane; Gondcaille, Catherine; Lizard, Gérard; Savary, Stéphane

    2014-04-11

    The regulation of the ABCD2 gene is recognized as a possible therapeutic target for X-linked adrenoleukodystrophy, a rare neurodegenerative disease caused by mutations in the ABCD1 gene. Up-regulation of ABCD2 expression has indeed been demonstrated to compensate for ABCD1 deficiency, restoring peroxisomal β-oxidation of very-long-chain fatty acids. Besides the known inducers of the ABCD2 gene (phenylbutyrate and histone deacetylase inhibitors, fibrates, dehydroepiandrosterone, thyroid hormone and thyromimetics), this review will focus on LXR antagonists and 22S-hydroxycholesterol, recently described as inducers of ABCD2 expression. Several LXR antagonists have been identified and their possible indication for neurodegenerative disorders will be discussed. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Role of family D ATP-binding cassette transporters (ABCD) in cancer.

    Science.gov (United States)

    Hlaváč, Viktor; Souček, Pavel

    2015-10-01

    ATP-binding cassette (ABC) transporters, belonging to the family D, are expressed in peroxisomes, endoplasmic reticulum or lysosomes. ABCD transporters play a role in transport of lipids, bile acids and vitamin B12 and associate with peroxisomal disorders. ABCD1 performs transport of coenzyme A esters of very-long-chain fatty acids (VLCFA) in peroxisomes and a number of mutations in ABCD1 gene were linked to an X-linked adrenoleucodystrophy (X-ALD). The role of ABCD transporters in tumour growth has not been studied in detail, but there is some evidence that ABCDs levels differ between undifferentiated stem or tumour cells and differentiated cells suggesting a possible link to tumorigenesis. In this mini-review, we discuss the available information about the role of ABCD transporters in cancer. © 2015 Authors; published by Portland Press Limited.

  6. Efficient substructure searching of large chemical libraries: the ABCD chemical cartridge.

    Science.gov (United States)

    Agrafiotis, Dimitris K; Lobanov, Victor S; Shemanarev, Maxim; Rassokhin, Dmitrii N; Izrailev, Sergei; Jaeger, Edward P; Alex, Simson; Farnum, Michael

    2011-12-27

    Efficient substructure searching is a key requirement for any chemical information management system. In this paper, we describe the substructure search capabilities of ABCD, an integrated drug discovery informatics platform developed at Johnson & Johnson Pharmaceutical Research & Development, L.L.C. The solution consists of several algorithmic components: 1) a pattern mapping algorithm for solving the subgraph isomorphism problem, 2) an indexing scheme that enables very fast substructure searches on large structure files, 3) the incorporation of that indexing scheme into an Oracle cartridge to enable querying large relational databases through SQL, and 4) a cost estimation scheme that allows the Oracle cost-based optimizer to generate a good execution plan when a substructure search is combined with additional constraints in a single SQL query. The algorithm was tested on a public database comprising nearly 1 million molecules using 4,629 substructure queries, the vast majority of which were submitted by discovery scientists over the last 2.5 years of user acceptance testing of ABCD. 80.7% of these queries were completed in less than a second and 96.8% in less than ten seconds on a single CPU, while on eight processing cores these numbers increased to 93.2% and 99.7%, respectively. The slower queries involved extremely generic patterns that returned the entire database as screening hits and required extensive atom-by-atom verification.

  7. Synthesis, Structure and Antimicrobial Properties of Novel Benzalkonium Chloride Analogues with Pyridine Rings

    Directory of Open Access Journals (Sweden)

    Bogumił Brycki

    2017-01-01

    Full Text Available Quaternary ammonium compounds (QACs are a group of compounds of great economic significance. They are widely used as emulsifiers, detergents, solubilizers and corrosion inhibitors in household and industrial products. Due to their excellent antimicrobial activity QACs have also gained a special meaning as antimicrobials in hospitals, agriculture and the food industry. The main representatives of the microbiocidal QACs are the benzalkonium chlorides (BACs, which exhibit biocidal activity against most bacteria, fungi, algae and some viruses. However, the misuses of QACs, mainly at sublethal concentrations, can lead to an increasing resistance of microorganisms. One of the ways to avoid this serious problem is the introduction and use of new biocides with modified structures instead of the biocides applied so far. Therefore new BAC analogues P13–P18 with pyridine rings were synthesized. The new compounds were characterized by NMR, FT-IR and ESI-MS methods. PM3 semiempirical calculations of molecular structures and the heats of formation of compounds P13–P18 were also performed. Critical micellization concentrations (CMCs were determined to characterize the aggregation behavior of the new BAC analogues. The antimicrobial properties of novel QACs were examined by determining their minimal inhibitory concentration (MIC values against the fungi Aspergillus niger, Candida albicans, Penicillium chrysogenum and bacteria Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The MIC values of N,N-dimethyl-N-(4-methylpyridyl-N-alkylammonium chlorides for fungi range from 0.1 to 12 mM and for bacteria, they range from 0.02 to 6 mM.

  8. The Readout Tests of Freiburg Hybrids using ABCD chips

    CERN Document Server

    Dolezal, Z; Ketterer, C; Ludwig, J; Rieth, G; Rogalla, M; Runge, K; Unno, N

    1999-01-01

    New SCT forward hybrids have been completed in Freiburg. Their performance, based on readout tests using batches of ABCD chips is presented in this note. A so called Kapton hybrid (K1) was equipped with 6 n-type ABCD-2 chips and a 6 cm n-in-n forward detector. A subset of the 768 strips were ganged together to simulate 12 cm long strips. After careful grounding no oscillations were observed. The noise values measured are about 0.3 fC (1900 electrons) for 12 cm strips, 0.18 fC (1200 electrons) for 6 cm strips and below 0.09 fC (550 electrons) for unbonded channels. The gain, extracted with a 3 point response curve fit, was rather high (100 -140) and almost independent of FE-Bias current.

  9. The new modified ABCD method for gastric neoplasm screening.

    Science.gov (United States)

    Park, Chan Hyuk; Kim, Eun Hye; Jung, Da Hyun; Chung, Hyunsoo; Park, Jun Chul; Shin, Sung Kwan; Lee, Sang Kil; Lee, Yong Chan

    2016-01-01

    The ABCD screening method was developed for risk stratification of gastric cancer. It is unclear whether the ABCD method can predict the risk of gastric neoplasms, including gastric adenomas, as observed for gastric cancer. We aimed to devise a modified ABCD method for predicting gastric neoplasms. We reviewed 562 patients who had undergone upper gastrointestinal tract endoscopy and whose serum IgG anti-Helicobacter pylori antibody, gastrin, and pepsinogen (PG) I and PG II data were available. Patients were classified into the following four groups: H. pylori antibody negative and normal PG level (group A), H. pylori antibody positive and normal PG level (group B), H. pylori antibody positive and low PG level (group C), and H. pylori antibody negative and low PG level (group D). The PG I/PG II ratio was lower in patients with gastric neoplasms than in patients without these lesions (gastric adenoma vs gastric cancer vs no neoplasm, 3.7 ± 2.0 vs 3.8 ± 1.8 vs 4.9 ± 2.1, P neoplasms were 3.1 for H. pylori antibody negative patients and 4.1 for H. pylori antibody positive patients. A higher group grade was associated with a significantly higher proportion of gastric neoplasms [odds ratio (95 % confidence interval), group A, reference; group B, 1.783 (1.007-3.156); group C, 3.807 (2.382-6.085); and group D, 5.862 (2.427-14.155)]. The modified ABCD method using two different cutoff values according to the H. pylori antibody status was useful for predicting the presence of gastric neoplasms. This method might be a supplementary screening tool for both gastric adenoma and gastric cancer. However, further studies will be required to provide a definitive conclusion.

  10. Validity of ABCD Rule of Dermoscopy in Clinical Practice.

    Science.gov (United States)

    Ahnlide, Ingela; Bjellerup, Mats; Nilsson, Fredrik; Nielsen, Kari

    2016-03-01

    The ABCD rule of dermoscopy was developed to facilitate the dermoscopic differentiation between benign and malignant melanocytic lesions. However, there is a lack of studies on its validity in clinical practice. The aim of this study was to evaluate the accuracy of the algorithm used bedside, compared with the accuracy of the preliminary preoperative diagnosis, and to rate physicians' level of confidence in the diagnosis. Melanocytic tumours were preoperatively scored bedside, according to the ABCD algorithm; 309 cases (46 melanomas and 263 naevi) were included. A sensitivity of 83% and specificity of 45% were found for the ABCD algorithm. A comparable sensitivity (74%), but a significantly higher specificity (91%), was found for the preliminary diagnosis. Interestingly, there was a considerable percentage (19.6%) of early melanomas for which a malignant diagnosis was not preoperatively expected, indicating that it is important to maintain generous indications for excision or to practise short-term follow-up of ambiguous lesions in order to detect early melanomas.

  11. Influence of chemical structure on skin reactions induced by antiepileptic drugs--the role of the aromatic ring.

    Science.gov (United States)

    Wang, Xiang-Qing; Shi, Xiao-Bing; Au, Ran; Chen, Fu-Shun; Wang, Fang; Lang, Sen-Yang

    2011-05-01

    Here we assessed whether the presence of an aromatic ring as a commonality in chemical structures of AEDs can explain skin reaction. We found that 164 cases of skin reactions associated with the use of AEDs were reported. Aromatic AEDs were suspected in 88.41% (145/164) of patients with skin reactions versus 59.80% (2316/3873) of patients without skin reactions. The presence of an aromatic ring in the chemical structure was associated with a significant increased risk of skin reactions (adjusted ROR 3.50; 95% CI 2.29, 5.35). Among the aromatic AEDs, skin reactions were significantly associated with carbamazepine, lamotrigine, and oxarbazepine. These results confirm that the presence of an aromatic ring as a common feature in chemical structures of AEDs partly explains AED-skin reactions. Skin reactions were reported triple as frequently with aromatic AEDs than with non-aromatic AEDs. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Influence of structure of lactones with the methylcyclohexene and dimethylcyclohexene ring on their biotransformation and antimicrobial activity.

    Science.gov (United States)

    Wińska, Katarzyna; Grabarczyk, Małgorzata; Mączka, Wanda; Żarowska, Barbara; Maciejewska, Gabriela; Anioł, Mirosław

    2017-05-01

    The aim of this article is influence of the structure of lactones with the methylcyclohexene and dimethylcyclohexene ring on their biotransformation and antimicrobial activity. This work was based on the general remark that even the smallest change in the structure of a compound can affect its biological properties. The results of the biotransformation of four bicyclic unsaturated lactones with one or two methyl groups in the cyclohexene ring was tested using fifteen fungal strains (Fusarium species, Penicillium species, Absidia species, Cunninghamella japonica, and Pleurotus ostreatus) and five yeast strains (Yarrowia lipolytica, Rhodorula marina, Rhodorula rubra, Candida viswanathii, and Saccharomyces cerevisiae). During these transformations, new epoxylactone and hydroxylactone were obtained. The relationship between the substrate structure and the ability of the microorganisms to transform them were analysed. Only compounds with C-O bond of lactone ring in the equatorial position were transformed by fungus. All presented here lactones were examined also for their antimicrobial activity. It turned out that these compounds exhibited growth inhibition of bacteria and fungi, mainly Bacillus subtilis, Candida albicans, Aspergillus niger, and Penicillium expansum.

  13. Self assembly of microparticles in stable ring structures in an optical trap

    CERN Document Server

    Haldar, Arijit; Roy, Basudev; Gupta, S Dutta; Banerjee, Ayan

    2011-01-01

    Micro-particle self assembly under the influence of optical forces produced by higher order optical beams or by projection of a hologram into the trapping volume is well known. In this paper, we report the spontaneous formation of a ring of identical microspheres (each with diameter 1.1 um in conventional single beam optical tweezers having standing wave geometry with the sample chamber consisting of a cover slip and glass slide, and a usual TEM00 Gaussian beam. The effects of different experimental parameters on the ring formation are studied extensively. The experimental observations are backed by theoretical simulations based on a plane wave decomposition of the forward and backward propagating Gaussian beams. The ring patterns are shown to be caused due to geomterical aberrations produced by focusing the Gaussian beam using a high numerical aperture microscope objective into stratified media. It is found that the thickness of the stratified media and the standing wave geometry itself play a critical role ...

  14. Eight novel mutations in the ABCD1 gene and clinical characteristics of 25 Chinese patients with X-linked adrenoleukodystrophy.

    Science.gov (United States)

    Chu, Shan-Shan; Ye, Jun; Zhang, Hui-Wen; Han, Lian-Shu; Qiu, Wen-Juan; Gao, Xiao-Lan; Gu, Xue-Fan

    2015-11-01

    X-linked adrenoleukodystrophy (X-ALD) is a fatal neurodegenerative disease caused by mutations in the adenosine triphosphate-binding cassette D1 (ABCD1) gene. This study aimed to retrospectively investigate the clinical characteristics of 25 patients with X-ALD including members of large pedigrees, to analyze ABCD1 gene mutations, the effect of gene novel variants on ALD protein (ALDP) structure and function, and to expand gene mutation spectrum of Chinese patients. Twenty-five male patients diagnosed with X-ALD were enrolled in this study. The clinical characteristics of the patients were retrospectively summarized by reviewing medical records or telephone consultation. ABCD1 gene mutations were analyzed. The pathogenicity of novel missense variants was analyzed using cobalt constraint-based multiple protein alignment tool, polymorphism phenotyping, sorting intolerant from tolerant, Align-Grantham variation and Grantham deviation, and Swiss-Program Database Viewer 4.04 software, respectively. Childhood cerebral form ALD (CCALD) is the most common phenotype (64%) in the 25 patients with X-ALD. The progressive deterioration of neurological and cognitive functions is the main clinical feature. The demyelination of the brain white matter and elevated plasma very long chain fatty acids (VLCFAs) were found in all patients. Different phenotypes were also presented within family members of the patients. Twenty-two different mutations including 8 novel mutations in the ABCD1 gene were identified in the 25 patients. Of the mutations, 63.6% were missense mutations and 34.8% located in exon 1. The amino acid residues of three novel missense mutations in eight species were highly conserved, and were predicted to be "probably" damaging to ALDP function. The other five novel mutations were splice, nonsense, deletion or duplication mutations. CCALD is the most common phenotype (64%) in our patients with X-ALD. Eight novel mutations in the ABCD1 gene identified are disease

  15. Sling-on-a-Ring: Structure for an elevator to LEO

    OpenAIRE

    Meulenberg, A.; Poston, T.

    2011-01-01

    Various proposed space elevators may bypass the financial and environmental limits on rocket technology, but all have their own problems. A Low-Earth-Orbit, LEO, rotovator-based space-elevator version called 'sling-on-a-ring' may overcome them. This mass-lifting system uses the spatial stability of an orbital ring, accessorized for transfer and storage of momentum and electrical power. A high-tensile-strength equatorial circum-terra loop of colossal-carbon tube, CCT, fiber has solar-power and...

  16. Silicon Oxynitride Optical Waveguide Ring Resonator Utilizing a Two-Mode Interferometer Structure

    Directory of Open Access Journals (Sweden)

    Kaixin Chen

    2012-01-01

    Full Text Available Silicon oxynitride (SiOxNy, SiON optical waveguide ring resonator, in which a two-mode interferometer is used to replace the directional coupler in a conventional ring resonator, has been designed and fabricated. Preliminary results exhibit the same of free spectral range of 100 GHz but different quality factors of 3700 and 3900 at 1550 nm for transverse electric (TE and transverse magnetic (TM mode, respectively. The extinction ratio is more than 18 dB over the entire C-band, and the insertion loss is lower than 9.5 dB for TE and TM mode.

  17. The structure of balanced big Cohen-Macaulay modules over Cohen-Macaulay rings

    DEFF Research Database (Denmark)

    Holm, Henrik Granau

    2017-01-01

    Over a Cohen–Macaulay (CM) local ring, we characterize those modules that can be obtained as a direct limit of finitely generated maximal CM modules. We point out two consequences of this characterization: (1) Every balanced big CM module, in the sense of Hochster, can be written as a direct limi...

  18. Unexpected morphological changes within hippocampal structures in a photochemical ring model of cerebral ischaemia.

    Science.gov (United States)

    Rafałowska, Janina; Gadamski, Roman; Dziewulska, Dorota; Zielonka, Piotr; Ogonowska, Wanda; Lazarewicz, Jerzy W

    2009-01-01

    A photochemical ring model of ischaemia was introduced in the middle of the nineteen eighties. Irradiation by a laser or arc lamp followed by intravenous injection of rose bengal resulted in thrombosis of pial and superficial cortical vessels. This ring model imitated focal ischaemic damage in humans. In our experiment twenty-seven Wistar rats of both sexes weighing 250-300 grams were examined. A photochemical ring model based on irradiation of the area of parietal bone 4 mm posteriorly to the bregma and 4 mm laterally from the sagittal suture was applied. A ring-shaped light beam with a wavelength of 510-540 nm with 5 mm diameter was generated by a high pressure discharge lamp at a power of 400 W. Two groups of rats treated and untreated with MK-801 and two rings of the thickness of 0.35 mm and 0.5 mm were used in the experiment. Morphological examination was performed in animals sacrificed 1 and 4 days after the irradiation. On formalin-fixed and paraffin-embedded slices HE staining method and immunoreaction with antibodies to ubiquitin were applied. Our material confirmed well known information about the dynamics of infarct breakdown, ischaemic-induced angiogenesis, glial reaction and other typical changes described previously in handbooks and numerous papers. In the experiment, morphological changes were more intensive after the irradiation by 0.5 mm than 0.35 mm irradiating rings and 4 days than one day after the irradiation. A surprising finding observed in some of the examined animals was more intensive neuronal damage after treatment with MK-801. Another unpredicted discovery was intensive morphological alterations found in CA4 and CA3 hippocampal sectors. Moreover, these alterations were not limited to the damaged hemisphere, but were also observed contralaterally. In some of the rats, ischaemic and necrotic cells were additionally found within both parasagittal areas. We connect this atypical localization of the ischaemic changes with dispersion of light

  19. Matrix vaccination guidelines : 2015 ABCD recommendations for indoor/outdoor cats, rescue shelter cats and breeding catteries

    NARCIS (Netherlands)

    Hosie, Margaret J; Addie, Diane D; Boucraut-Baralon, Corine; Egberink, Herman; Frymus, Tadeusz; Gruffydd-Jones, Tim; Hartmann, Katrin; Horzinek, Marian C; Lloret, Albert; Lutz, Hans; Marsilio, Fulvio; Pennisi, Maria Grazia; Radford, Alan D; Thiry, Etienne; Truyen, Uwe; Möstl, Karin

    OVERVIEW: In 2013, the ABCD published 'Matrix vaccination guidelines: ABCD recommendations for indoor/outdoor cats, rescue shelter cats and breeding catteries' in a Special Issue of the Journal of Feline Medicine and Surgery (Volume 15, Issue 7, pages 540-544). The ABCD's vaccination recommendations

  20. Of Chains and Rings: Synthetic Strategies and Theoretical Investigations for Tuning the Structure of Silver Coordination Compounds and Their Applications

    Directory of Open Access Journals (Sweden)

    Tünde Vig Slenters

    2010-05-01

    Full Text Available Varying the polyethyleneglycol spacer between two (iso-nicotinic groups of the ligand systems, a large structural variety of silver coordination compounds was obtained, starting with zero-dimensional ring systems, via one-dimensional chains, helices and double-helices to two-dimensional polycatenanes. Theoretical calculations help to understand their formation and allow predictions in some cases. These structures can be tuned by careful design of the ligand, the use of solvent and the counter ions, influencing also other important properties such as light stability and solubility. The latter is important in the context of biomedical applications, using silver compounds as antimicrobial agents.

  1. "Now I Know My ABCDs": Asset-Based Community Development with School Children in Ethiopia

    Science.gov (United States)

    Johnson Butterfield, Alice K.; Yeneabat, Mulu; Moxley, David P.

    2016-01-01

    Asset-based community development (ABCD) is a promising practice for communities to engage in self-determination through the efforts residents invest in identifying community assets, framing and documenting the issues communities face, and taking action to advance quality of life. The ABCD literature does not report on the application of ABCD…

  2. Inter-rater Reliability and Misclassification of the ABCD(2) Score after Transient Ischemic Attack.

    Science.gov (United States)

    Ishida, Koto; Kasner, Scott E; Cucchiara, Brett

    2015-06-01

    The ABCD(2) score was initially developed as a simple tool to help first-line clinicians identify patients at highest short-term risk for stroke after transient ischemic attack (TIA). The score is increasingly used for risk stratification of TIA patients, but little is known about its inter-rater reliability. The aim of the present study was to prospectively assess the inter-rater reliability of the ABCD(2) score in patients with TIA, including a comparison among raters of different specialties. Patients presenting to the emergency department with TIA within 48 hours of onset were prospectively evaluated. TIA was defined as acute onset of focal cerebral or monocular symptoms lasting less than 24 hours and presumed because of a vascular cause. Only patients who were asymptomatic at the time of enrollment were eligible. ABCD(2) scores determined by raters of different specialties were compared with those of a vascular neurology attending. Estimated component and total scores and ABCD(2) risk category were compared between raters. Reliability was assessed using unweighted kappa statistics. A total of 362 evaluations resulting in ABCD(2) scores were performed. In addition to the vascular neurology attending, scores were generated by internal medicine (n = 72), emergency medicine (n = 37), and neurology junior (n = 92) and senior (n = 57) residents. Based on attending scores, 35% of patients were categorized as low risk (ABCD(2) score, 0-3), 50% as moderate risk (ABCD(2) score, 4-5), and 16% as high risk (ABCD(2) score, 6-7). Inter-rater reliability was fair for ABCD(2) total score (κ = .26) and category (κ = .29). Raters agreed with the vascular neurology attending 67% (95% confidence interval [CI], 61%-73%) of the time for ABCD(2) category and 52% (95% CI, 46%-58%) of the time for ABCD(2) total score. Disagreement more often resulted in a lower score by the raters as compared with the vascular neurology attending for both ABCD(2) total score and

  3. Structure and flexibility of the C-ring in the electromotor of rotary F(0F(1-ATPase of pea chloroplasts.

    Directory of Open Access Journals (Sweden)

    Shai Saroussi

    Full Text Available A ring of 8-15 identical c-subunits is essential for ion-translocation by the rotary electromotor of the ubiquitous F(OF(1-ATPase. Here we present the crystal structure at 3.4Å resolution of the c-ring from chloroplasts of a higher plant (Pisum sativum, determined using a native preparation. The crystal structure was found to resemble that of an (ancestral cyanobacterium. Using elastic network modeling to investigate the ring's eigen-modes, we found five dominant modes of motion that fell into three classes. They revealed the following deformations of the ring: (I ellipsoidal, (II opposite twisting of the luminal circular surface of the ring against the stromal surface, and (III kinking of the hairpin-shaped monomers in the middle, resulting in bending/stretching of the ring. Extension of the elastic network analysis to rings of different c(n-symmetry revealed the same classes of dominant modes as in P. sativum (c(14. We suggest the following functional roles for these classes: The first and third classes of modes affect the interaction of the c-ring with its counterparts in F(O, namely subunits a and bb'. These modes are likely to be involved in ion-translocation and torque generation. The second class of deformation, along with deformations of subunits γ and ε might serve to elastically buffer the torque transmission between F(O and F(1.

  4. Effects of a modulated vortex structure on the diffraction dynamics of ring Airy Gaussian beams.

    Science.gov (United States)

    Huang, Xianwei; Shi, Xiaohui; Deng, Zhixiang; Bai, Yanfeng; Fu, Xiquan

    2017-09-01

    The evolution of the ring Airy Gaussian beams with a modulated vortex in free space is numerically investigated. Compared with the unmodulated vortex, the unique property is that the beam spots first break up, and then gather. The evolution of the beams is influenced by the parameters of the vortex modulation, and the splitting phenomenon gets enhanced with multiple rings becoming light spots if the modulation depth increases. The symmetric branch pattern of the beam spots gets changed when the number of phase folds increases, and the initial modulation phase only impacts the angle of the beam spots. Moreover, a large distribution factor correlates to a hollow Gaussian vortex shape and weakens the splitting and gathering trend. By changing the initial parameters of the vortex modulation and the distribution factor, the peak intensity is greatly affected. In addition, the energy flow and the angular momentum are elucidated with the beam evolution features being confirmed.

  5. Development of Cone Wedge Ring Expansion Test to Evaluate Mechanical Properties of Clad Tubing Structure

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-10-01

    To determine the hoop tensile properties of irradiated fuel cladding in a hot cell, a cone wedge ring expansion test method was developed. A four-piece wedge insert was designed with tapered angles matched to the cone shape of a loading piston. The ring specimen was expanded in the radial direction by the lateral expansion of the wedges under the downward movement of the piston. The advantages of the proposed method are that implementation of the test setup in a hot cell is simple and easy, and that it enables a direct strain measurement of the test specimen from the piston’s vertical displacement soon after the wedge-clad contact resistance is initiated.

  6. Saturn's dynamic D ring

    Science.gov (United States)

    Hedman, M.M.; Burns, J.A.; Showalter, M.R.; Porco, C.C.; Nicholson, P.D.; Bosh, A.S.; Tiscareno, M.S.; Brown, R.H.; Buratti, B.J.; Baines, K.H.; Clark, R.

    2007-01-01

    The Cassini spacecraft has provided the first clear images of the D ring since the Voyager missions. These observations show that the structure of the D ring has undergone significant changes over the last 25 years. The brightest of the three ringlets seen in the Voyager images (named D72), has transformed from a narrow, ring. Cassini also finds that the locations of other narrow features in the D ring and the structure of the diffuse material in the D ring differ from those measured by Voyager. Furthermore, Cassini has detected additional ringlets and structures in the D ring that were not observed by Voyager. These include a sheet of material just interior to the inner edge of the C ring that is only observable at phase angles below about 60??. New photometric and spectroscopic data from the ISS (Imaging Science Subsystem) and VIMS (Visual and Infrared Mapping Spectrometer) instruments onboard Cassini show the D ring contains a variety of different particle populations with typical particle sizes ranging from 1 to 100 microns. High-resolution images reveal fine-scale structures in the D ring that appear to be variable in time and/or longitude. Particularly interesting is a remarkably regular, periodic structure with a wavelength of ??? 30 ?? km extending between orbital radii of 73,200 and 74,000 km. A similar structure was previously observed in 1995 during the occultation of the star GSC5249-01240, at which time it had a wavelength of ??? 60 ?? km. We interpret this structure as a periodic vertical corrugation in the D ring produced by differential nodal regression of an initially inclined ring. We speculate that this structure may have formed in response to an impact with a comet or meteoroid in early 1984. ?? 2006 Elsevier Inc. All rights reserved.

  7. White Ring; White ring

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, H.; Yuzawa, H. [Nikken Sekkei Ltd., Osaka (Japan)

    1998-01-05

    White Ring is a citizen`s gymnasium used for figure skating and short track speed skating games of 18th Winter Olympic Games in 1998. White Ring is composed of a main-arena and a sub-arena. For the main-arena with an area 41mtimes66m, an ice link can be made by disengaging the potable floor and by flowing brine in the bridged polystyrene pipes embedded in the concrete floor. Due to the fortunate groundwater in this site, well water is used for the outside air treatment energy in 63% during heating and in 35% during cooling. Ammonia is used as a cooling medium for refrigerating facility. For the heating of audience area in the large space, heat load from the outside is reduced by enhancing the heat insulation performance of the roof of arena. The audience seats are locally heated using heaters. For the White Ring, high quality environment is realized for games through various functions of the large-scale roof of the large space. Success of the big event was expected. 15 figs., 4 tabs.

  8. Design and performance analysis of delay insensitive multi-ring structures

    DEFF Research Database (Denmark)

    Sparsø, Jens; Staunstrup, Jørgen

    1993-01-01

    A set of simple design and performance analysis techniques that have been successfully used to design a number of nontrivial delay insensitive circuits is described. Examples are building blocks for digital filters and a vector multiplier using a serial-parallel multiply and accumulate algorithm....... The vector multiplier circuit has been laid out, submitted for fabrication and successfully tested. Throughout the analysis elements from this design are used to illustrate the design and performance analysis techniques. The design technique is based on a data flow approach using pipelines and rings...

  9. Use of silica-encapsulated Pseudomonas sp. strain NCIB 9816-4 in biodegradation of novel hydrocarbon ring structures found in hydraulic fracturing waters.

    Science.gov (United States)

    Aukema, Kelly G; Kasinkas, Lisa; Aksan, Alptekin; Wackett, Lawrence P

    2014-08-01

    The most problematic hydrocarbons in hydraulic fracturing (fracking) wastewaters consist of fused, isolated, bridged, and spiro ring systems, and ring systems have been poorly studied with respect to biodegradation, prompting the testing here of six major ring structural subclasses using a well-characterized bacterium and a silica encapsulation system previously shown to enhance biodegradation. The direct biological oxygenation of spiro ring compounds was demonstrated here. These and other hydrocarbon ring compounds have previously been shown to be present in flow-back waters and waters produced from hydraulic fracturing operations. Pseudomonas sp. strain NCIB 9816-4, containing naphthalene dioxygenase, was selected for its broad substrate specificity, and it was demonstrated here to oxidize fundamental ring structures that are common in shale-derived waters but not previously investigated with this or related enzymes. Pseudomonas sp. NCIB 9816-4 was tested here in the presence of a silica encasement, a protocol that has previously been shown to protect bacteria against the extremes of salinity present in fracking wastewaters. These studies demonstrate the degradation of highly hydrophobic compounds by a silica-encapsulated model bacterium, demonstrate what it may not degrade, and contribute to knowledge of the full range of hydrocarbon ring compounds that can be oxidized using Pseudomonas sp. NCIB 9816-4. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  10. Use of Silica-Encapsulated Pseudomonas sp. Strain NCIB 9816-4 in Biodegradation of Novel Hydrocarbon Ring Structures Found in Hydraulic Fracturing Waters

    Science.gov (United States)

    Aukema, Kelly G.; Kasinkas, Lisa; Aksan, Alptekin

    2014-01-01

    The most problematic hydrocarbons in hydraulic fracturing (fracking) wastewaters consist of fused, isolated, bridged, and spiro ring systems, and ring systems have been poorly studied with respect to biodegradation, prompting the testing here of six major ring structural subclasses using a well-characterized bacterium and a silica encapsulation system previously shown to enhance biodegradation. The direct biological oxygenation of spiro ring compounds was demonstrated here. These and other hydrocarbon ring compounds have previously been shown to be present in flow-back waters and waters produced from hydraulic fracturing operations. Pseudomonas sp. strain NCIB 9816-4, containing naphthalene dioxygenase, was selected for its broad substrate specificity, and it was demonstrated here to oxidize fundamental ring structures that are common in shale-derived waters but not previously investigated with this or related enzymes. Pseudomonas sp. NCIB 9816-4 was tested here in the presence of a silica encasement, a protocol that has previously been shown to protect bacteria against the extremes of salinity present in fracking wastewaters. These studies demonstrate the degradation of highly hydrophobic compounds by a silica-encapsulated model bacterium, demonstrate what it may not degrade, and contribute to knowledge of the full range of hydrocarbon ring compounds that can be oxidized using Pseudomonas sp. NCIB 9816-4. PMID:24907321

  11. Inorganic glass ceramic slip rings

    Science.gov (United States)

    Glossbrenner, E. W.; Cole, S. R.

    1972-01-01

    Prototypes of slip rings have been fabricated from ceramic glass, a material which is highly resistant to deterioration due to high temperature. Slip ring assemblies were not structurally damaged by mechanical tests and performed statisfactorily for 200 hours.

  12. A field investigation of the basaltic ring structures of the Channeled Scabland and the relevance to Mars

    Science.gov (United States)

    Kestay, Laszlo P.; Jaeger, Windy L.

    2015-01-01

    The basaltic ring structure (BRS) is a class of peculiar features only reported in the Channeled Scabland of eastern Washington State. They have been suggested to be good analogs, however, for some circular features on Mars. BRSs are found where Pleistocene floods scoured the Columbia River Basin, stripping off the uppermost part of the Miocene Columbia River Basalt Group and exposing structures that were previously embedded in the lava. The “Odessa Craters,” near Odessa, WA, are 50–500-m-wide BRSs that are comprised of discontinuous, concentric outcrops of subvertically-jointed basalt and autointrusive dikes. Detailed field investigation of the Odessa Craters in planform and a cross-sectional exposure of a similar structure above Banks Lake, WA, lead us to propose that BRSs formed by concurrent phreatovolcanism and lava flow inflation. In this model, phreatovolcanic (a.k.a., “rootless”) cones formed on a relatively thin, active lava flow; the lava flow inflated around the cones, locally inverting topography; tensile stresses caused concentric fracturing of the lava crust; lava from within the molten interior of the flow exploited the fractures and buried the phreatovolcanic cones; and subsequent erosive floods excavated the structures. Another population of BRSs near Tokio Station, WA, consists of single-ringed, raised-rimmed structures that are smaller and more randomly distributed than the Odessa Craters. We find evidence for a phreatovolcanic component to the origin as well, and hypothesize that they are either flood-eroded phreatovolcanic cones or Odessa Crater-like BRSs. This work indicates that BRSs are not good analogs to the features on Mars because the martian features are found on the uneroded surfaces. Despite this, the now superseded concepts for BRS formation are useful for understanding the formation of the martian features.

  13. Token Ring Project

    Directory of Open Access Journals (Sweden)

    Adela Ionescu

    2007-01-01

    Full Text Available Ring topology is a simple configuration used to connect processes that communicate among themselves. A number of network standards such as token ring, token bus, and FDDI are based on the ring connectivity. This article will develop an implementation of a ring of processes that communicate among themselves via pipe links. The processes are nodes in the ring. Each process reads from its standard input and writes in its standard output. N-1 process redirects the its standard output to a standard input of the process through a pipe. When the ring-structure is designed, the project can be extended to simulate networks or to implement algorithms for mutual exclusion

  14. Ring-Shaped Phosphinoamido-Magnesium-Hydride Complexes: Syntheses, Structures, Reactivity, and Catalysis.

    Science.gov (United States)

    Fohlmeister, Lea; Stasch, Andreas

    2016-07-11

    A series of magnesium(II) complexes bearing the sterically demanding phosphinoamide ligand, L(-) =Ph2 PNDip(-) , Dip=2,6-diisopropylphenyl, including heteroleptic magnesium alkyl and hydride complexes are described. The ligand geometry enforces various novel ring and cluster geometries for the heteroleptic compounds. We have studied the stoichiometric reactivity of [(LMgH)4 ] towards unsaturated substrates, and investigated catalytic hydroborations and hydrosilylations of ketones and pyridines. We found that hydroborations of two ketones with pinacolborane using various Mg precatalysts is very rapid at room temperature with very low catalyst loadings, and ketone hydrosilylation using phenylsilane is rapid at 70 °C. Our studies point to an insertion/σ-bond metathesis catalytic cycle of an in situ formed "MgH2 " active species. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Neptune's rings

    Science.gov (United States)

    1999-01-01

    This 591-second exposure of the rings of Neptune were taken with the clear filter by the Voyager 2 wide-angle camera. The two main rings are clearly visible and appear complete over the region imaged. Also visible in this image is the inner faint ring and the faint band which extends smoothly from the ring roughly halfway between the two bright rings. Both of these newly discovered rings are broad and much fainter than the two narrow rings. The bright glare is due to over-exposure of the crescent on Neptune. Numerous bright stars are evident in the background. Both bright rings have material throughout their entire orbit, and are therefore continuous. The Voyager Mission is conducted by JPL for NASA's Office of Space Science and Applications.

  16. Structure design and motion simulation of the pin-cycloid gear planetary reducer with ring-plate-type

    Science.gov (United States)

    Duan, Hongjie; Li, Lijun; Tao, Junyi

    2017-06-01

    The pin-cycloid gear planetary reducer with ring-plate-type is a new type of reducers. It has high transmission ratio range and high efficiency. In this paper the working principle of pin-cycloid gear planetary reducer is discussed, and the structure of the reducer is designed. Especially for the complexity and the difficulty in modelling of the cycloid gear tooth profile, the parametric design module of cycloid gear is developed to solve the cycloid gear modelling problem through the second development of Solid Works. At last, the speed schemes of the input shaft and output shaft of the reducer are obtained by the motion simulation. Through the analysis of the simulation curves, the rationality of the structure design is proved, which provides a theoretical basis for the design and manufacture of the reducer.

  17. Increasing access to dental care for medicaid preschool children: the Access to Baby and Child Dentistry (ABCD) program.

    Science.gov (United States)

    Grembowski, D; Milgrom, P M

    2000-01-01

    OBJECTIVE: Washington State's Access to Baby and Child Dent stry (ABCD) Program, first implemented in Spokane County in 1995, offers extended dental benefits to participating Medicaid-enrolled children and higher fees for certified providers. This study aimed to determine the program's effect on children's dental utilization and dental fear, and on parent satisfaction and knowledge. METHODS: The study used a posttest-only comparison group design. Trained interviewers conducted telephone interviews with 465 parents of chi dren ages 13 to 36 months (49% ABCD, 51% Medicaid-enrolled children not in ABCD). One year later, 282 of 465 parents completed a follow-up survey. Utilization and expenditures were calculated from Medicaid claims. RESULTS: Forty-three percent of children in the ABCD Program visited a dentist in the follow-up year, compared with 12% of Medicaid-enrolled children not in the ABCD Program. An ABCD child was 5.3 times as likely to have had at least one dental visit as a child not in the program. ABCD children were 4 to 13 times as likely to have used specific dental services. Parents of ABCD children were more likely to report having ever tried to make a dental appointment, less likely to report that their children were fearful of the dentist, and were more satisfied, compared to parents of non-ABCD children. CONCLUSION: The authors conclude that the ABCD Program was effective in increasing access for preschool children enrolled in Medicaid, reducing dental fear, and increasing parent satisfaction. PMID:11236017

  18. Solvent micro-evaporation and concentration gradient synergistically induced crystallization of poly(L-lactide) and ring banded supra-structures with radial periodic variation of thickness

    DEFF Research Database (Denmark)

    Huang, Shaoyong; Li, Hongfei; Wen, Huiying

    2014-01-01

    The crystalline morphology and structure of poly(L-lactide) (PLLA) in a PLLA film-chloroform system were investigated by means of wide angle X-ray diffraction (WAXD), polarized optical microscopy (POM) and atomic force microscopy (AFM). Birefringent and nonbirefringent ring banded supra-structure......The crystalline morphology and structure of poly(L-lactide) (PLLA) in a PLLA film-chloroform system were investigated by means of wide angle X-ray diffraction (WAXD), polarized optical microscopy (POM) and atomic force microscopy (AFM). Birefringent and nonbirefringent ring banded supra...

  19. Ring theory

    CERN Document Server

    Rowen, Louis H

    1991-01-01

    This is an abridged edition of the author's previous two-volume work, Ring Theory, which concentrates on essential material for a general ring theory course while ommitting much of the material intended for ring theory specialists. It has been praised by reviewers:**""As a textbook for graduate students, Ring Theory joins the best....The experts will find several attractive and pleasant features in Ring Theory. The most noteworthy is the inclusion, usually in supplements and appendices, of many useful constructions which are hard to locate outside of the original sources....The audience of non

  20. Gaussian Beam Propagation in a Kerr Type Metamaterial Medium Using ABCD Matrix Method

    Science.gov (United States)

    Keshavarz, A.; Naseri, M.

    2016-08-01

    In this paper, a split step ABCD matrix method is suggested to investigate Gaussian beam propagation in a Kerr type metamaterial medium. This method is based on dividing the medium interval into subsequent steps. Meanwhile, Gaussian beam profile in every step is obtained by finding the ABCD matrix of that particular step, and is used to find the ABCD matrix of the next step. Results of the suggested matrix method have been compared with the results of numerical split-step Fourier method for a Kerr medium, which indicates a good agreement. Then, we use the ABCD matrix to investigate Gaussian beams propagation in a Kerr type metamaterial, which is also in agreement with pervious results by other methods.

  1. [Introduction and interpretation of abcd classification system for subaxial cervical spine injury].

    Science.gov (United States)

    Chen, Zhida; Lin, Bin; Yu, Zhiyi; Li, Bingwen

    2014-11-01

    To introduce and interpret ABCD classification system for subaxial cervical spine injury. The literature related to subaxial cervical spine injury classification system was extensively reviewed, analyzed, and summarized so as to introduce the ABCD classification system. The ABCD classification system for subaxial cervical spine injury consists of 3 parts. The first part of the proposed classification is an anatomical description of the injury; it delivers the information whether injury is bony, ligamentous, or a combined one. The second part is the classification of nerve function, spinal stenosis, and spinal instability. The last part is optional and denotes radiological examination which is used to define injury type. Several letters have been used for simplicity to deliver the largest amount of information. And a treatment algorithm based on the proposed classification is suggested. The ABCD classification system is proposed for simplification. However further evaluation of this classification is needed.

  2. On the interference of two Gaussian beams and their ABCD matrix representation.

    Science.gov (United States)

    Arain, Muzammil A; Mueller, Guido

    2009-10-12

    Gaussian beam propagation is well described by the q-parameter and the ABCD matrices. A variety of ABCD matrices are available that represent commonly occurring scenarios/components in optics. One important phenomenon that has not been studied in detail is the interference of two optical beams with different q-parameters undergoing interference. In this paper, we describe the effect of interference of two Gaussian beams. We derive an ABCD matrix for the addition of two beams that takes into account both the amplitude and phase difference between two beams. This ABCD matrix will help greatly in determining the propagation of beams inside complex interferometers and finding the solutions for the coupled cavity Eigenmodes.

  3. TCAD Simulations of ATLAS Pixel Guard Ring and Edge Structure for SLHC Upgrade

    CERN Document Server

    Lounis, A; The ATLAS collaboration; Calderini, G; Marchiori, G; Benoit, M; Dinu, N

    2010-01-01

    In this work, the magnitude of the electric field and the depletion inside a simplified two dimensional model of the ATLAS planar pixel sensor for the insertable b-layer and the super-LHC upgrade have been studied. The parameters influencing the breakdown behavior were studied using a finite-element method to solve the drift-diffusion equations coupled to Poisson's equation. Using these models, the number of guard rings, dead edge width and sensor's thickness were modified with respect to the ATLAS actual pixel sensor to investigate their influence on the sensor's depletion at the edge and on its internal electrical field distribution. The goal of the simulation is to establish a model to discriminate between different designs and to select the most optimized to fit the needs in radiation hardness and low material budget of ATLAS inner detector during super-LHC operation. A three defects level model has been implemented in the simulations to study the behavior of such sensors under different level of irradiat...

  4. ABCD, an Open Source Software for Modern Libraries

    Directory of Open Access Journals (Sweden)

    Sangeeta Namdev Dhamdhere

    2011-12-01

    Full Text Available Nowadays, librarians are using various kinds of open source software for different purposes such as library automation, digitization, institutional repository, content management. ABCD, acronym for Automatisación de Bibliotécas y Centros de Documentación, is one of such software. It caters to almost all present needs of modern libraries of any sizes. It offers a solution to library automation with ISBD as well as local formats. It has excellent indexing and retrieval features based on UNESCO’s ISIS technology, a web OPAC, and a library Portal with integrated meta-search and content management system to manage online as well as offline digital resources and physical documents and media.

  5. Molecular characterization of X-linked adrenoleukodystrophy in a Tunisian family: identification of a novel missense mutation in the ABCD1 gene.

    Science.gov (United States)

    Kallabi, Fakhri; Hadj Salem, Ikhlass; Ben Salah, Ghada; Ben Turkia, Hadhami; Ben Chehida, Amel; Tebib, Neji; Fakhfakh, Faiza; Kamoun, Hassen

    2013-01-01

    X-linked adrenoleukodystrophy (X-ALD) is a recessive neurodegenerative disorder that affects the brain's white matter and is associated with adrenal insufficiency. It is characterized by an abnormal function of the peroxisomes, which leads to an accumulation of very long-chain fatty acids (VLCFA) in plasma and tissues, especially in the cortex of the adrenal glands and the white matter of the central nervous system, causing demyelinating disease and adrenocortical insufficiency (Addison's disease). X-ALD is caused by a mutation in the ABCD1 gene (ATP-binding cassette, subfamily D, member 1), which encodes the adrenoleukodystrophy protein involved in the transport of fatty acids into the peroxisome for degradation. We report here a disease-related variant in the ABCD1 gene in a 19-year-old Tunisian boy with childhood cerebral adrenoleukodystrophy. The diagnosis was based on clinical symptoms, high levels of VLCFA in plasma, typical MRI pattern and molecular analysis. Molecular analysis by direct sequencing of the ABCD1 gene showed the presence of a novel missense mutation c.284C>A (p.Ala95Asp) occurring in the transmembrane domain in the proband, his mother and his sister. Using bioinformatic tools we suggest that this novel variant may have deleterious effects on adrenoleukodystrophy protein structure and function. Copyright © 2013 S. Karger AG, Basel.

  6. Bi-2212 and Y123 highly curved single-crystal-like objects: whiskers, bows and ring-like structures

    Science.gov (United States)

    Badica, Petre; Agostino, Angelo; Mizanur Rahman Khan, Mohammad; Cagliero, Stefano; Plapcianu, Carmen; Pastero, Linda; Truccato, Marco; Hayasaka, Yuichiro; Jakob, Gerhard

    2012-10-01

    High-temperature superconducting objects of Bi2Sr2CaCu2O8 and Y Ba2Cu3O7 highly curved in the ab-plane, such as curved/kinked whiskers, bows and ring-like structures, were obtained within a solid-liquid-solid (SLS) grass-like growth mechanism. As-grown objects are crystals with three-dimensional epitaxy similar to conventional single crystals: they can be viewed as crystal parts ‘cut’ from a conventional rectangular crystal. Between our curved objects and conventional crystals, whiskers or thin films there are some differences in the superconducting properties induced only by the shape factors and no new physics is observed. Some details of the growth mechanism are discussed, emphasizing curved-line formation.

  7. Structural and Functional Basis for an EBNA1 Hexameric Ring in Epstein-Barr Virus Episome Maintenance.

    Science.gov (United States)

    Deakyne, Julianna S; Malecka, Kimberly A; Messick, Troy E; Lieberman, Paul M

    2017-10-01

    Epstein-Barr virus (EBV) establishes a stable latent infection that can persist for the life of the host. EBNA1 is required for the replication, maintenance, and segregation of the latent episome, but the structural features of EBNA1 that confer each of these functions are not completely understood. Here, we have solved the X-ray crystal structure of an EBNA1 DNA-binding domain (DBD) and discovered a novel hexameric ring oligomeric form. The oligomeric interface pivoted around residue T585 as a joint that links and stabilizes higher-order EBNA1 complexes. Substitution mutations around the interface destabilized higher-order complex formation and altered the cooperative DNA-binding properties of EBNA1. Mutations had both positive and negative effects on EBNA1-dependent DNA replication and episome maintenance with OriP. We found that one naturally occurring polymorphism in the oligomer interface (T585P) had greater cooperative DNA binding in vitro , minor defects in DNA replication, and pronounced defects in episome maintenance. The T585P mutant was compromised for binding to OriP in vivo as well as for assembling the origin recognition complex subunit 2 (ORC2) and trimethylated histone 3 lysine 4 (H3K4me3) at OriP. The T585P mutant was also compromised for forming stable subnuclear foci in living cells. These findings reveal a novel oligomeric structure of EBNA1 with an interface subject to naturally occurring polymorphisms that modulate EBNA1 functional properties. We propose that EBNA1 dimers can assemble into higher-order oligomeric structures important for diverse functions of EBNA1. IMPORTANCE Epstein-Barr virus is a human gammaherpesvirus that is causally associated with various cancers. Carcinogenic properties are linked to the ability of the virus to persist in the latent form for the lifetime of the host. EBNA1 is a sequence-specific DNA-binding protein that is consistently expressed in EBV tumors and is the only viral protein required to maintain the viral

  8. The utility of twins in developmental cognitive neuroscience research: How twins strengthen the ABCD research design.

    Science.gov (United States)

    Iacono, William G; Heath, Andrew C; Hewitt, John K; Neale, Michael C; Banich, Marie T; Luciana, Monica M; Madden, Pamela A; Barch, Deanna M; Bjork, James M

    2017-09-12

    The ABCD twin study will elucidate the genetic and environmental contributions to a wide range of mental and physical health outcomes in children, including substance use, brain and behavioral development, and their interrelationship. Comparisons within and between monozygotic and dizygotic twin pairs, further powered by multiple assessments, provide information about genetic and environmental contributions to developmental associations, and enable stronger tests of causal hypotheses, than do comparisons involving unrelated children. Thus a sub-study of 800 pairs of same-sex twins was embedded within the overall Adolescent Brain and Cognitive Development (ABCD) design. The ABCD Twin Hub comprises four leading centers for twin research in Minnesota, Colorado, Virginia, and Missouri. Each site is enrolling 200 twin pairs, as well as singletons. The twins are recruited from registries of all twin births in each State during 2006-2008. Singletons at each site are recruited following the same school-based procedures as the rest of the ABCD study. This paper describes the background and rationale for the ABCD twin study, the ascertainment of twin pairs and implementation strategy at each site, and the details of the proposed analytic strategies to quantify genetic and environmental influences and test hypotheses critical to the aims of the ABCD study. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Non-Commutative Ring Theory

    CERN Document Server

    López-Permouth, Sergio

    1990-01-01

    The papers of this volume share as a common goal the structure and classi- fication of noncommutative rings and their modules, and deal with topics of current research including: localization, serial rings, perfect endomorphism rings, quantum groups, Morita contexts, generalizations of injectivitiy, and Cartan matrices.

  10. ABCD2 is a direct target of β-catenin and TCF-4: implications for X-linked adrenoleukodystrophy therapy.

    Science.gov (United States)

    Park, Chul-Yong; Kim, Han-Soo; Jang, Jiho; Lee, Hyunji; Lee, Jae Souk; Yoo, Jeong-Eun; Lee, Dongjin R; Kim, Dong-Wook

    2013-01-01

    X-linked adrenoleukodystrophy (X-ALD) is a peroxisomal disorder caused by mutations in the ABCD1 gene that encodes the peroxisomal ATP-binding cassette (ABC) transporter subfamily D member 1 protein (ABCD1), which is referred to as the adrenoleukodystrophy protein (ALDP). Induction of the ABCD2 gene, the closest homolog of ABCD1, has been mentioned as a possible therapeutic option for the defective ABCD1 protein in X-ALD. However, little is known about the transcriptional regulation of ABCD2 gene expression. Here, through in silico analysis, we found two putative TCF-4 binding elements between nucleotide positions -360 and -260 of the promoter region of the ABCD2 gene. The transcriptional activity of the ABCD2 promoter was strongly increased by ectopic expression of β-catenin and TCF-4. In addition, mutation of either or both TCF-4 binding elements by site-directed mutagenesis decreased promoter activity. This was further validated by the finding that β-catenin and the promoter of the ABCD2 gene were pulled down with a β-catenin antibody in a chromatin immunoprecipitation assay. Moreover, real-time PCR analysis revealed that β-catenin and TCF-4 increased mRNA levels of ABCD2 in both a hepatocellular carcinoma cell line and primary fibroblasts from an X-ALD patient. Interestingly, we found that the levels of very long chain fatty acids were decreased by ectopic expression of ABCD2-GFP as well as β-catenin and TCF-4. Taken together, our results demonstrate for the first time the direct regulation of ABCD2 by β-catenin and TCF-4.

  11. ABCD2 is a direct target of β-catenin and TCF-4: implications for X-linked adrenoleukodystrophy therapy.

    Directory of Open Access Journals (Sweden)

    Chul-Yong Park

    Full Text Available X-linked adrenoleukodystrophy (X-ALD is a peroxisomal disorder caused by mutations in the ABCD1 gene that encodes the peroxisomal ATP-binding cassette (ABC transporter subfamily D member 1 protein (ABCD1, which is referred to as the adrenoleukodystrophy protein (ALDP. Induction of the ABCD2 gene, the closest homolog of ABCD1, has been mentioned as a possible therapeutic option for the defective ABCD1 protein in X-ALD. However, little is known about the transcriptional regulation of ABCD2 gene expression. Here, through in silico analysis, we found two putative TCF-4 binding elements between nucleotide positions -360 and -260 of the promoter region of the ABCD2 gene. The transcriptional activity of the ABCD2 promoter was strongly increased by ectopic expression of β-catenin and TCF-4. In addition, mutation of either or both TCF-4 binding elements by site-directed mutagenesis decreased promoter activity. This was further validated by the finding that β-catenin and the promoter of the ABCD2 gene were pulled down with a β-catenin antibody in a chromatin immunoprecipitation assay. Moreover, real-time PCR analysis revealed that β-catenin and TCF-4 increased mRNA levels of ABCD2 in both a hepatocellular carcinoma cell line and primary fibroblasts from an X-ALD patient. Interestingly, we found that the levels of very long chain fatty acids were decreased by ectopic expression of ABCD2-GFP as well as β-catenin and TCF-4. Taken together, our results demonstrate for the first time the direct regulation of ABCD2 by β-catenin and TCF-4.

  12. Structure-activity relationship studies of illudins: analogues possessing a spiro-cyclobutane ring.

    Science.gov (United States)

    McMorris, Trevor C; Cong, Qiang; Kelner, Michael J

    2003-12-12

    Bicyclic and tricyclic analogues of anticancer sesquiterpene illudin S have been synthesized. These contain a spiro-cyclobutane instead of spiro-cyclopropane structure. The cytotoxicity of the former is less than that of the corresponding cyclopropane-containing compounds.

  13. Self-assembled coffee-ring colloidal crystals for structurally colored contact lenses.

    Science.gov (United States)

    Xie, Zhuoying; Li, Linliang; Liu, Panmiao; Zheng, Fuyin; Guo, Liuyang; Zhao, Yuanjin; Jin, Lu; Li, Tingting; Gu, Zhongze

    2015-02-25

    A circlular structural-colored contact lens is reported, which is fabricated by replicating self-assembled colloidal photonic crystal templates. The structural-colored contact lenses not only display variable and brilliant color under light illumination, but also avoid the addition of any colorants to the hydrogel lenses and prevent the potential harm posed by traditional colored contact lenses. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Dual curved photonic crystal ring resonator based channel drop filter using two-dimensional photonic crystal structure

    Energy Technology Data Exchange (ETDEWEB)

    Chhipa, Mayur Kumar, E-mail: mayurchhipa1@gmail.com [Deptt. of Electronics and Communication Engineering, Government Engineering College Ajmer Rajasthan INDIA (India); Dusad, Lalit Kumar [Rajasthan Technical University Kota, Rajasthan (India)

    2016-05-06

    In this paper channel drop filter (CDF) is designed using dual curved photonic crystal ring resonator (PCRR). The photonic band gap (PBG) is calculated by plane wave expansion (PWE) method and the photonic crystal (PhC) based on two dimensional (2D) square lattice periodic arrays of silicon (Si) rods in air structure have been investigated using finite difference time domain (FDTD) method. The number of rods in Z and X directions is 21 and 20 respectively with lattice constant 0.540 nm and rod radius r = 0.1 µm. The channel drop filter has been optimized for telecommunication wavelengths λ = 1.591 µm with refractive indices 3.533. In the designed structure further analysis is also done by changing whole rods refractive index and it has been observed that this filter may be used for filtering several other channels also. The designed structure is useful for CWDM systems. This device may serve as a key component in photonic integrated circuits. The device is ultra compact with the overall size around 123 µm{sup 2}.

  15. Design and performance of the ABCD chip for the binary readout of silicon strip detectors in the ATLAS semiconductor tracker

    CERN Document Server

    Dabrowski, W; Buttar, C M; Cindro, V; Clarks, A G; Dawson, I; Dorfan, D; Dubbs, T; Falconer, N; French, M; Greenall, A; Grillo, A A; Happer, R; Jarron, Pierre; Kaplon, J; Kudlaty, J; Kramberger, G; Lacasta, C; La Marra, D; Macina, Daniela; Mandic, I; Mikuz, M; Meddeler, G; Milgrome, O; Niggli, H; Phillips, P W; Roe, S; Smith, A; Spieler, H; Spencer, E; Szczygiel, R; Weilhammer, Peter; Wolter, M; Zsenei, A

    2000-01-01

    The ABCD design is a single chip implementation of the binary readout architecture for silicon strip detectors in the ATLAS semiconductor tracker. The prototype chip has been manufactured successfully in the DMILL process. In the paper we present the design of the chip and the measurement results. The basic analogue performance of the ABCD design has been evaluated using a prototype SCT module equipped with the ABCD chips. The digital performance has been evaluated using a general purpose IC tester. The measurements confirmed that all blocks of the ABCD design are fully functional and the chips meet all basic requirements of the SCT. (7 refs).

  16. Relativistic ring models

    Energy Technology Data Exchange (ETDEWEB)

    Ujevic, Maximiliano [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil). Centro de Ciencias Naturais e Humanas; Letelier, Patricio S.; Vogt, Daniel [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Matematica, Estatistica e Computacao Cientifica. Dept. de Matematica Aplicada

    2011-07-01

    Full text: Relativistic thick ring models are constructed using previously found analytical Newtonian potential-density pairs for flat rings and toroidal structures obtained from Kuzmin-Toomre family of discs. This was achieved by inflating previously constructed Newtonian ring potentials using the transformation |z|{yields}{radical}z{sup 2} + b{sup 2}, and then finding their relativistic analog. The models presented have infinite extension but the physical quantities decays very fast with the distance, and in principle, one could make a cut-off radius to consider it finite. In particular, we present systems with one ring, two rings and a disc with a ring. Also, the circular velocity of a test particle and its stability when performing circular orbits are presented in all these models. Using the Rayleigh criterion of stability of a fluid at rest in a gravitational field, we find that the different systems studied present a region of non-stability that appears in the intersection of the disc and the ring, and between the rings when they become thinner. (author)

  17. ABCD2 identifies a subclass of peroxisomes in mouse adipose tissue.

    Science.gov (United States)

    Liu, Xiaoxi; Liu, Jingjing; Lester, Joshua D; Pijut, Sonja S; Graf, Gregory A

    2015-01-02

    ATP-binding cassette transporter D2 (D2) is an ABC half transporter that is thought to promote the transport of very long-chain fatty acyl-CoAs into peroxisomes. Both D2 and peroxisomes increase during adipogenesis. Although peroxisomes are essential to both catabolic and anabolic lipid metabolism, their function, and that of D2, in adipose tissues remain largely unknown. Here, we investigated the D2 localization and the proteome of D2-containing organelles, in adipose tissue. Centrifugation of mouse adipose homogenates generated a fraction enriched with D2, but deficient in peroxisome markers including catalase, PEX19, and ABCD3 (D3). Electron microscopic imaging of this fraction confirmed the presence of D2 protein on an organelle with a dense matrix and a diameter of ∼ 200 nm, the typical structure and size of a microperoxisome. D2 and PEX19 antibodies recognized distinct structures in mouse adipose. Immunoisolation of the D2-containing compartment confirmed the scarcity of PEX19 and proteomic profiling revealed the presence of proteins associated with peroxisome, endoplasmic reticulum (ER), and mitochondria. D2 is localized to a distinct class of peroxisomes that lack many peroxisome proteins, and may associate physically with mitochondria and the ER. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Caffeic Acid Phenethyl Ester Induces Adrenoleukodystrophy (Abcd2) Gene in Human X-ALD Fibroblasts and Inhibits the Proinflammatory Response in Abcd1/2 Silenced Mouse Primary Astrocytes

    Science.gov (United States)

    Singh, Jaspreet; Khan, Mushfiquddin; Singh, Inderjit

    2013-01-01

    X-linked adrenoleukodystrophy (X-ALD) is a peroxisomal disorder caused by mutations in the ABCD1 gene. Accumulation of very long chain fatty acids (VLCFA) that have been attributed to reduced peroxisomal VLCFA β-oxidation activity are the hallmark of the disease. Overexpression of ABCD2 gene, the closest homolog of ABCD1, has been shown to compensate for ABCD1, thus correcting the VLCFA derrangement. The accumulation of VLCFA leads to a neuroinflammatory disease process associated with demyelination of the cerebral white matter. The present study underlines the importance of caffeic acid phenethyl ester (CAPE) in inducing the expression of ABCD2 (ALDRP), and normalizing the peroxisomal β-oxidation as well as the levels of saturated and monounsaturated VLCFAs in cultured human skin fibroblasts of X-ALD patients. The expression of ELOVL1, the single elongase catalyzing the synthesis of both saturated VLCFA (C26:0) and mono-unsaturated VLCFA (C26:1), was also reduced by CAPE treatment. Importantly, CAPE upregulated Abcd2 expression and peroxisomal β-oxidation and lowered the VLCFA levels in Abcd1-deficient U87 astrocytes and B12 oligodendrocytes. In addition, using Abcd1/Abcd2-silenced mouse primary astrocytes we examined the effects of CAPE in VLCFA-induced inflammatory response. CAPE treatment decreased the inflammatory response as the expression of inducible nitric oxide synthase, inflammatory cytokine, and activation of NF-κB in Abcd1/Abcd2-silenced mouse primary astrocytes was reduced. The observations indicate that CAPE corrects both the metabolic disease of VLCFA as well as secondary inflammatory disease; therefore, it may be a potential drug candidate to be tested for X-ALD therapy in humans. PMID:23318275

  19. Double stop-band structure near half-integer tunes in high-intensity rings

    Directory of Open Access Journals (Sweden)

    K. Moriya

    2016-11-01

    Full Text Available This paper addresses a detailed experimental study of collective instability bands generated near every half-integer tune per lattice period by coherent dipole and quadrupole resonances. Both instabilities appear side by side or overlap each other but are mostly separable because the dipole resonance often creates a narrower stop band accompanied by more severe particle losses. The separation of these low-order resonance bands becomes greater as the beam intensity increases. In principle, the double stop-band structure can be formed even without machine imperfections when the beam’s initial phase-space profile is deviated from the ideal stationary distribution. The tabletop ion-trap system called “S-POD” is employed to experimentally demonstrate the parameter dependence of the double stop-band structure. Numerical simulations are also performed for comparison with experimental observations.

  20. The effect of annulation of benzene rings on the photophysics and electronic structure of tetraazachlorin molecules

    Science.gov (United States)

    Pershukevich, P. P.; Volkovich, D. I.; Gladkov, L. L.; Dudkin, S. V.; Kuzmitsky, V. A.; Makarova, E. A.; Solovyev, K. N.

    2017-10-01

    The photophysics and electronic structure of tribenzotetraazachlorins (H2, Zn, and Mg), which are novel analogues of phtalocyanines, have been studied experimentally and theoretically. At 293 K, the electronic absorption, fluorescence, and fluorescence excitation spectra are recorded and the fluorescence quantum yield and lifetime, as well as the quantum yield of singlet oxygen generation, are measured; at 77 K, the fluorescence, fluorescence excitation, and fluorescence polarization spectra are recorded and the fluorescence lifetime values are measured. The dependences of the absorption spectra and photophysical parameters on the structure variation are analyzed in detail. Quantum-chemical calculations of the electronic structure and absorption spectra of tribenzotetraazachlorins (H2, Mg) are performed using the INDO/Sm method (modified INDO/S method) based on molecular-geometry optimization by the DFT PBE/TZVP method. The results of quantum-chemical calculations of the electronic absorption spectra are in very good agreement with the experimental data for the transitions to two lower electronic states.

  1. Nanoscale borromean rings.

    Science.gov (United States)

    Cantrill, Stuart J; Chichak, Kelly S; Peters, Andrea J; Stoddart, J Fraser

    2005-01-01

    The molecular expression of topologically interesting structures represents a formidable challenge for synthetic chemists. The nontrivial link known as the Borromean rings has long been regarded as one of the most ambitious targets in this field. Of ancient provenance, this symbol comprises three interlocked rings in an inseparable union, but cut any one of the rings and the whole assembly unravels into three separate pieces. This Account delineates different strategies that can be applied to the formation of molecules possessing this distinctive topology, culminating with two successful syntheses of such compounds, thus cutting the Gordian knot of topological chemistry.

  2. Predictive Structure and Topology of Peroxisomal ATP-Binding Cassette (ABC Transporters

    Directory of Open Access Journals (Sweden)

    Pierre Andreoletti

    2017-07-01

    Full Text Available The peroxisomal ATP-binding Cassette (ABC transporters, which are called ABCD1, ABCD2 and ABCD3, are transmembrane proteins involved in the transport of various lipids that allow their degradation inside the organelle. Defective ABCD1 leads to the accumulation of very long-chain fatty acids and is associated with a complex and severe neurodegenerative disorder called X-linked adrenoleukodystrophy (X-ALD. Although the nucleotide-binding domain is highly conserved and characterized within the ABC transporters family, solid data are missing for the transmembrane domain (TMD of ABCD proteins. The lack of a clear consensus on the secondary and tertiary structure of the TMDs weakens any structure-function hypothesis based on the very diverse ABCD1 mutations found in X-ALD patients. Therefore, we first reinvestigated thoroughly the structure-function data available and performed refined alignments of ABCD protein sequences. Based on the 2.85  Å resolution crystal structure of the mitochondrial ABC transporter ABCB10, here we propose a structural model of peroxisomal ABCD proteins that specifies the position of the transmembrane and coupling helices, and highlight functional motifs and putative important amino acid residues.

  3. Structure-activity relationship studies of 1,7-diheteroarylhepta-1,4,6-trien-3-ones with two different terminal rings in prostate epithelial cell models.

    Science.gov (United States)

    Wang, Rubing; Zhang, Xiaojie; Chen, Chengsheng; Chen, Guanglin; Sarabia, Cristian; Zhang, Qiang; Zheng, Shilong; Wang, Guangdi; Chen, Qiao-Hong

    2017-06-16

    To systematically investigate the structure-activity relationships of 1,7-diheteroarylhepta-1,4,6-trien-3-ones in three human prostate cancer cell models and one human prostate non-neoplastic epithelial cell model, thirty five 1,7-diarylhepta-1,4,6-trien-3-ones with different terminal heteroaromatic rings have been designed for evaluation of their anti-proliferative potency in vitro. These target compounds have been successfully synthesized through two sequential Horner-Wadsworth-Emmons reactions starting from the appropriate aldehydes and tetraethyl (2-oxopropane-1,3-diyl)bis(phosphonate). Their anti-proliferative potency against PC-3, DU-145 and LNCaP human prostate cancer cell lines can be significantly enhanced by the manipulation of the terminal heteroaromatic rings, further demonstrating the utility of 1,7-diarylhepta-1,4,6-trien-3-one as a potential scaffold for the development of anti-prostate cancer agents. The optimal analog 40 is 82-, 67-, and 39-fold more potent than curcumin toward the three prostate cancer cell lines, respectively. The experimental data also reveal that the trienones with two different terminal aromatic rings possess greater potency toward three prostate cancer cell lines, but also have greater capability of suppressing the proliferation of PWR-1E benign human prostate epithelial cells, as compared to the corresponding counterparts with two identical terminal rings and curcumin. The terminal aromatic rings also affect the cell apoptosis perturbation. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. Structure of a Glomulin-RBX1-CUL1 Complex: Inhibition of a RING E3 Ligase through Masking of Its E2-Binding Surface

    Energy Technology Data Exchange (ETDEWEB)

    Duda, David M.; Olszewski, Jennifer L.; Tron, Adriana E.; Hammel, Michal; Lambert, Lester J.; Waddell, M. Brett; Mittag, Tanja; DeCaprio, James A.; Schulman, Brenda A. (BWH); (LBNL); (SJCH); (DFCI)

    2012-11-01

    The approximately 300 human cullin-RING ligases (CRLs) are multisubunit E3s in which a RING protein, either RBX1 or RBX2, recruits an E2 to catalyze ubiquitination. RBX1-containing CRLs also can bind Glomulin (GLMN), which binds RBX1's RING domain, regulates the RBX1-CUL1-containing SCF{sup FBW7} complex, and is disrupted in the disease Glomuvenous Malformation. Here we report the crystal structure of a complex between GLMN, RBX1, and a fragment of CUL1. Structural and biochemical analyses reveal that GLMN adopts a HEAT-like repeat fold that tightly binds the E2-interacting surface of RBX1, inhibiting CRL-mediated chain formation by the E2 CDC34. The structure explains the basis for GLMN's selectivity toward RBX1 over RBX2, and how disease-associated mutations disrupt GLMN-RBX1 interactions. Our study reveals a mechanism for RING E3 ligase regulation, whereby an inhibitor blocks E2 access, and raises the possibility that other E3s are likewise controlled by cellular proteins that mask E2-binding surfaces to mediate inhibition.

  5. Cesium cholate: determination of X-ray crystal structure indicates participation of the ring hydroxyl groups in metal binding.

    Science.gov (United States)

    Sun, Y; Soloway, R D; Han, Y-Z; Yang, G-D; Wang, X-Z; Liu, Z-J; Yang, Z-L; Xu, Y-Z; Wu, J-G

    2002-04-01

    The crystal structure of cesium cholate, C(24)H(36)(OH)(3) COOCs has been determined with three-dimensional X-ray diffractometer data. It crystallized in the monoclinic space group P2(1) with unit-cell dimensions a = 11.543(5) A, b = 8.614(3) A, and c = 12.662(5) A, beta(deg) = 107.95(2), V = 1197.7 A(3) and Z = 2. The atomic parameters were refined to a final r = 0.0269 and R(omega) = 0.0280 for 2342 observed reflections. Each Cs(+) is coordinated to 7 oxygen atoms from 5 different cholate anions with Cs-O distances ranging from 2.957(4) A to 3.678(5) A. In this crystal, 5 cholates are coordinated with 1 Cs(+), and 5 Cs(+) are coordinated with 1 cholate anion. Carboxyl and all the 3 ring hydroxyl groups of cholate anion participate in binding to Cs(+) simultaneously, and there is no water molecule coordinated with the Cs(+). The pattern of successive rows arranged with polar (p) and non-polar (n) faces in apposition leads to the formation of a sandwich sheet structure with polar and non-polar channels. The Cs ions lie within the polar interior of the sandwich. The H-bond network is reorganized in forming cesium cholate from cholic acid. All the oxygen atoms in cholate anion are involved in H-bonding reciprocally or with water molecules to form an extensive 3-dimensional network of H-bonds. Compared with cholic acid and other similar type of steroids, the coordination structure and H-bonding of Cs cholate crystal are distinct.

  6. Is the ABCD score useful for risk stratification of patients with acute transient ischemic attack?

    Science.gov (United States)

    Cucchiara, Brett L; Messe, Steve R; Taylor, Robert A; Pacelli, James; Maus, Douglas; Shah, Qaisar; Kasner, Scott E

    2006-07-01

    A 6-point scoring system (ABCD) was described recently for stratifying risk after transient ischemic attack (TIA). This score incorporates age (A), blood pressure (B), clinical features (C), and duration (D) of TIA. A score or =50% stenosis in a relevant artery, or a cardioembolic source warranting anticoagulation. All others were classified as low risk. Findings on diffusion-weighted MRI (DWI) were also evaluated when performed and patients classified as DWI+ or DWI-. Over 3 years, 117 patients were enrolled. Median time from symptom onset to enrollment was 25.2 hours (interquartile range 19.8 to 30.2). Overall, 26 patients (22%) were classified as high risk, including 2 strokes, 2 deaths, 15 with > or =50% stenosis, and 10 with cardioembolic source. The frequency of high-risk patients increased with ABCD score (0 to 1 13%; 2 8%; 3 17%; 4 27%; 5 26%; 6 30%; P for trend=0.11). ABCD scores in the 2 patients with stroke were 3 and 6. Of those who underwent MRI, 15 of 61 (25%) were DWI+, but this correlated poorly with ABCD score (0 to 1 17%; 2 10%; 3 36%; 4 24%; 5 13%; 6 60%; P for trend=0.24). Although the ABCD score has some predictive value, patients with a score <4 still have a substantial probability of having a high-risk cause of cerebral ischemia or radiographic evidence of acute infarction despite transient symptoms.

  7. ABCD(2) as a screening tool for cerebral infarction on stroke MRI?

    Science.gov (United States)

    Hotter, Benjamin A; Lechner, Jan M; Nolte, Christian H; Audebert, Heinrich J; Malzahn, Uwe; Heuschmann, Peter U; Fiebach, Jochen B; Jungehulsing, Gerhard J

    2012-01-01

    The newly proposed transient ischemic attack (TIA) definition demands for MRI exclusion of infarction. Due to limited resources other tools than MRI predicting tissue infarction would be valuable. We hypothesized that ABCD(2) risk score is a valid screening tool for diffusion-weighted imaging (DWI) lesions. TIA patients were prospectively enrolled in an observational MRI study to receive acute and follow-up stroke MRI. ABCD(2) scores were calculated, and sociodemographics and risk factors were recorded. One hundred and thirty-two TIA patients were enrolled over nine months. Five patients were excluded due to different diagnosis. Forty-five of the 127 remaining patients showed acute ischemic lesions on DWI. Median ABCD(2) scores for DWI-negative and -positive patients were 4 and 5, respectively. Ordinal, trichotomized and dichotomized ABCD(2) were significantly associated to DWI. Univariate analysis of single score items and other risk factors demonstrated unilateral weakness, duration of symptoms and smoking as predictive for DWI restrictions. In multivariate analysis unilateral weakness remained significant. High-risk ABCD(2) score due to the impact of hemiparesis is associated with the occurrence of DWI lesions but is still not accurate enough for a reliable differentiation of cerebrovascular events with and without MRI lesions. Copyright © 2012 S. Karger AG, Basel.

  8. [Evaluation of patients' learning about the ABCD rule: A randomized study in southern Brazil].

    Science.gov (United States)

    Müller, Karen Reetz; Bonamigo, Renan Rangel; Crestani, Thayse Antoniolli; Chiaradia, Gisele; Rey, Maria Carolina Widholzer

    2009-01-01

    the ABCD rule is used to guide physicians, health care professionals and patients to recognize the main characteristics of suspicious skin lesions for melanoma. In Brazil there are no studies to validate the use of the ABCD rule by patients after instructions given by dermatologists. to evaluate the learning of the ABCD rule by patients at a dermatology center of reference in the Southern region of Brazil. a randomized study, with 80 outpatients. The following were evaluated: sex, age, level of schooling, monthly income and access to means of communication. The intervention group received instructions regarding the use of the ABCD rule and the control group did not. Both groups were evaluated at three points in time (baseline; outside the office; and in the doctor's office, 15 days later) regarding their answers about a panel of photographs. The level of significance used was p ABCD rule can be used to train patients, above the age of 17 years, to identify changes that suggest melanoma. This learning is independent of sex, level of schooling, monthly income and access to means of communication, except the radio.

  9. Vascular ring

    DEFF Research Database (Denmark)

    Schmidt, Anne Mette S; Larsen, Signe H; Hjortdal, Vibeke E

    2018-01-01

    BACKGROUND: Vascular ring is a rare cause of recurrent respiratory infections, dysphagia and stridor. Surgical repair is considered safe but the long-term outcomes are unclear. The purpose of this study was to investigate the mortality and morbidity following vascular ring surgery in a single...... age of 1.4 years (range 0.008-64 years) were operated for vascular ring. Median follow-up was 6.8 years (range 2.4-34 years). Presenting symptoms were stridor (52%), dysphagia or vomiting (52%) and recurrent respiratory infections (48%). There were no early or late deaths. Three months postoperatively...

  10. Computer-automated ABCD versus dermatologists with different degrees of experience in dermoscopy.

    Science.gov (United States)

    Piccolo, Domenico; Crisman, Giuliana; Schoinas, Spyridon; Altamura, Davide; Peris, Ketty

    2014-01-01

    Dermoscopy is a very useful and non-invasive technique for in vivo observation and preoperative diagnosis of pigmented skin lesions (PSLs) inasmuch as it enables analysis of surface and subsurface structures that are not discernible to the naked eye. The authors used the ABCD rule of dermoscopy to test the accuracy of melanoma diagnosis with respect to a panel of 165 PSLs and the intra- and inter-observer diagnostic agreement obtained between three dermatologists with different degrees of experience, one General Practitioner and a DDA for computer-assisted diagnosis (Nevuscreen(®), Arkè s.a.s., Avezzano, Italy). 165 Pigmented Skin Lesions from 165 patients were selected. Histopathological examination revealed 132 benign melanocytic skin lesions and 33 melanomas. The kappa statistic, sensitivity, specificity and predictive positive and negative values were calculated to measure agreement between all the human observers and in comparison with the automated DDA. Our results revealed poor reproducibility of the semi-quantitative algorithm devised by Stolz et al. independently of observers' experience in dermoscopy. Nevuscreen(®) (Arkè s.a.s., Avezzano, Italy) proved to be 'user friendly' to all observers, thus enabling a more critical evaluation of each lesion and representing a helpful tool for clinicians without significant experience in dermoscopy in improving and achieving more accurate diagnosis of PSLs.

  11. Severe wear and tooth loss in wild ring-tailed lemurs (Lemur catta): a function of feeding ecology, dental structure, and individual life history.

    Science.gov (United States)

    Cuozzo, Frank P; Sauther, Michelle L

    2006-11-01

    The ring-tailed lemurs at Beza Mahafaly Special Reserve, Madagascar, exhibit a high frequency of severe wear and antemortem tooth loss. As part of a long-term study, we collected dental data on 83 living adult ring-tailed lemurs during 2003 and 2004. Among these individuals, 192 teeth were scored as absent. The most frequently missing tooth position is M1 (24%). As M1 is the first tooth to erupt, its high frequency of absence (primarily a result of wear) is not remarkable. However, the remaining pattern of tooth loss does not correlate with the sequence of eruption. We suggest that this pattern is a function of 1) feeding ecology, as hard, tough tamarind fruit is a key fallback food of ring-tailed lemurs living in gallery forests; 2) food processing, as tamarind fruit is primarily processed in the P3-M1 region of the mouth; and 3) tooth structure, as ring-tailed lemurs possess thin dental enamel. The incongruity between thin enamel and use of a hard, tough fallback food suggests that ring-tailed lemurs living in riverine gallery forests may rely on resources not used in the past. When comparing dental health in the same individuals (n=50) between 2003 and 2004, we found that individual tooth loss can show a rapid increase over the span of one year, increasing by as much as 20%. Despite this rapid loss, individuals are able to survive, sometimes benefiting from unintentional assistance from conspecifics, from which partially processed tamarind fruit is obtained. Although less frequent in this population, these longitudinal data also illustrate that ring-tailed lemurs lose teeth due to damage and disease, similar to other nonhuman primates. The relationship between tooth loss, feeding ecology, dental structure, and individual life history in this population has implications for interpreting behavior based on tooth loss in the hominid fossil record.

  12. Reinforcement core facilitates O-ring installation

    Science.gov (United States)

    1965-01-01

    Reinforcement core holds O-ring in place within a structure while adjacent parts are being assembled. The core in the O-ring adds circumferential rigidity to the O-ring material. This inner core does not appreciably affect the sectional elasticity or gland-sealing characteristics of the O-ring.

  13. Integrated interpretation of geophysical data of the Paleozoic structure in the northwestern part of the Siljan Ring impact crater, central Sweden

    Science.gov (United States)

    Muhamad, Harbe; Juhlin, Christopher; Malehmir, Alireza; Sopher, Daniel

    2018-01-01

    The Siljan Ring impact structure is the largest known impact structure in Europe and is Late Devonian in age. It contains a central uplift that is about 20-30 km in diameter and is surrounded by a ring-shaped depression. The Siljan area is one of the few areas in Sweden where the Paleozoic sequence has not been completely eroded, making it an important location for investigation of the geological and tectonic history of Baltica during the Paleozoic. The Paleozoic strata in this area also provide insight into the complex deformation processes associated with the impact. In this study we focus on the northwestern part of the Siljan Ring, close to the town of Orsa, with the main objective of characterizing the subsurface Paleozoic succession and uppermost Precambrian crystalline rocks along a series of seismic reflection profiles, some of which have not previously been published. We combine these seismic data with gravity and magnetic data and seismic traveltime tomography results to produce an integrated interpretation of the subsurface in the area. Our interpretation shows that the Paleozoic sequence in this area is of a relatively constant thickness, with a total thickness typically between 300 and 500 m. Faulting appears to be predominantly extensional, which we interpret to have occurred during the modification stage of the impact. Furthermore, based on the geophysical data in this area, we interpret that the impact related deformation to differ in magnitude and style from other parts of the Siljan Ring.

  14. A novel ABCD1 gene mutation in a Chinese patient with X-linked adrenoleukodystrophy.

    Science.gov (United States)

    Cai, Yan-na; Jiang, Min-yan; Liang, Cui-li; Peng, Min-zhi; Cheng, Jing; Sheng, Hui-ying; Fan, Li-ping; Chen, Xi-qing; Liu, Li

    2015-05-01

    X-linked adrenoleukodystrophy (X-ALD) (OMIM: 300100) is a recessive neurodegenerative disorder caused by defects in the ABCD1 gene on chromosome Xq28. Childhood cerebral ALD (CCALD) is the most frequent phenotype. We describe an affected boy who developed normally until he was 8 years old then suffered progressive neurological deficits that ultimately led to death. Diagnosis was based on clinical symptoms, an abnormal very long chain fatty acid profile in plasma, typical CCALD MRI pattern, and molecular analysis. Direct sequencing of the ABCD1 gene in this patient identified a novel splicing mutation (IVS1+1G>A) in intron 1, which is considered to be the pathogenic mutation. We have identified a novel ABCD1 mutation as the likely cause of CCALD in a Chinese patient.

  15. A mathematical analysis of the ABCD criteria for diagnosing malignant melanoma

    Science.gov (United States)

    Lee, Hyunju; Kwon, Kiwoon

    2017-03-01

    The medical community currently employs the ABCD (asymmetry, border irregularity, color variegation, and diameter of the lesion) criteria in the early diagnosis of a malignant melanoma. Although many image segmentation and classification methods are used to analyze the ABCD criteria, it is rare to see a study containing mathematical justification of the parameters that are used to quantify the ABCD criteria. In this paper, we suggest new parameters to assess asymmetry, border irregularity, and color variegation, and explain the mathematical meaning of the parameters. The suggested parameters are then tested with 24 skin samples. The parameters suggested for the 24 skin samples are displayed in three-dimensional coordinates and are compared to those presented in other studies (Ercal et al 1994 IEEE Trans. Biomed. Eng. 41 837-45, Cheerla and Frazier 2014 Int. J. Innovative Res. Sci., Eng. Technol. 3 9164-83) in terms of Pearson correlation coefficient and classification accuracy in determining the malignancy of the lesions.

  16. Topology and Structure/Function Correlation of Ring- and Gate-forming Domains in the Dynamic Secretin Complex of Thermus thermophilus.

    Science.gov (United States)

    Salzer, Ralf; D'Imprima, Edoardo; Gold, Vicki A M; Rose, Ilona; Drechsler, Moritz; Vonck, Janet; Averhoff, Beate

    2016-07-08

    Secretins are versatile outer membrane pores used by many bacteria to secrete proteins, toxins, or filamentous phages; extrude type IV pili (T4P); or take up DNA. Extrusion of T4P and natural transformation of DNA in the thermophilic bacterium Thermus thermophilus requires a unique secretin complex comprising six stacked rings, a membrane-embedded cone structure, and two gates that open and close a central channel. To investigate the role of distinct domains in ring and gate formation, we examined a set of deletion derivatives by cryomicroscopy techniques. Here we report that maintaining the N0 ring in the deletion derivatives led to stable PilQ complexes. Analyses of the variants unraveled that an N-terminal domain comprising a unique βββαβ fold is essential for the formation of gate 2. Furthermore, we identified four βαββα domains essential for the formation of the N2 to N5 rings. Mutant studies revealed that deletion of individual ring domains significantly reduces piliation. The N1, N2, N4, and N5 deletion mutants were significantly impaired in T4P-mediated twitching motility, whereas the motility of the N3 mutant was comparable with that of wild-type cells. This indicates that the deletion of the N3 ring leads to increased pilus dynamics, thereby compensating for the reduced number of pili of the N3 mutant. All mutants exhibit a wild-type natural transformation phenotype, leading to the conclusion that DNA uptake is independent of functional T4P. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Iron and pH-responsive FtrABCD ferrous iron utilization system of Bordetella species.

    Science.gov (United States)

    Brickman, Timothy J; Armstrong, Sandra K

    2012-11-01

    A putative operon encoding an uncharacterized ferrous iron transport (FtrABCD) system was previously identified in cDNA microarray studies. In growth studies using buffered medium at pH values ranging from pH 6.0 to 7.6, Bordetella pertussis and Bordetella bronchiseptica FtrABCD system mutants showed dramatic reductions in growth yields under iron-restricted conditions at pH 6.0, but had no growth defects at pH 7.6. Supplementation of culture medium with 2 mM ascorbate reductant was inhibitory to alcaligin siderophore-dependent growth at pH 7.6, but had a neglible effect on FtrABCD system-dependent iron assimilation at pH 6.0 consistent with its predicted specificity for ferrous iron. Unlike Bordetella siderophore-dependent and haem iron transport systems, and in agreement with its hypothesized role in transport of inorganic iron from periplasm to cytoplasm, FtrABCD system function did not require the TonB energy transduction complex. Gene fusion analysis revealed that ftrABCD promoter activity was maximal under iron-restricted growth conditions at acidic pH. The pH of human airway surface fluids ranges from pH 5.5 to 7.9, and the FtrABCD system may supply ferrous iron necessary for Bordetella growth in acidic host microenvironments in which siderophores are ineffective for iron retrieval. © 2012 Blackwell Publishing Ltd.

  18. Rapid identification of high-risk transient ischemic attacks: prospective validation of the ABCD score.

    Science.gov (United States)

    Sciolla, Rossella; Melis, Fabio

    2008-02-01

    A 6-point score, based on age, blood pressure, clinical features, and duration (ABCD), was shown to effectively stratify the short-term risk of stroke after a transient ischemic attack (TIA). Prospective validation in different populations of patients should precede its widespread use. Whether adding computed tomography (CT) scan findings to the score would improve its performance deserves exploring. We aimed to validate the ABCD score in a prospective cohort of patients accessing Emergency Departments within 24 hours of a TIA in an area of northern Italy and to acquire preliminary data on CT-based refinement. During a 6-month period, all TIA patients accessing the Emergency Departments of 13 Piemonte and Valle d'Aosta hospitals were prospectively enrolled and stratified according to the 6-point ABCD score and to a 7-point score (ABCDI, where I=imaging) incorporating CT findings. Of 274 patients, stroke occurred in 10 (3.6%) within 7 days and in 15 (5.5%) within 30 days. The ABCD score was predictive of stroke risk at both 7 and 30 days (odds ratio for every point of the score=2.55 at 7 days and 2.62 at 30 days; P for linear trend across the ABCD score levels=0.018 at 7 days and 0.0017 at 30 days). CT scan findings further increased prediction (odds ratio for every point of the score=2.68 at 7 days and 2.89 at 30 days; P for linear trend across the ABCDI score levels=0.0043 at 7 days and 0.0003 at 30 days). The ABCD score confirmed its prognostic value in this prospective cohort. CT results could further improve prediction.

  19. Uranus rings and two moons

    Science.gov (United States)

    1986-01-01

    Voyager 2 has discovered two 'shepherd' satellites associated with the rings of Uranus. The two moons -- designated 1986U7 and 1986U8 -- are seen here on either side of the bright epsilon ring; all nine of the known Uranian rings are visible. The image was taken Jan. 21, 1986, at a distance of 4.1 million kilometers (2.5 million miles) and resolution of about 36 km (22 mi). The image was processed to enhance narrow features. The epsilon ring appears surrounded by a dark halo as a result of this processing; occasional blips seen on the ring are also artifacts. Lying inward from the epsilon ring are the delta, gamma and eta rings; then the beta and alpha rings; and finally the barely visible 4, 5 and 6 rings. The rings have been studied since their discovery in 1977, through observations of how they diminish the light of stars they pass in front of. This image is the first direct observation of all nine rings in reflected sunlight. They range in width from about 100 km (60 mi) at the widest part of the epsilon ring to only a few kilometers for most of the others. The discovery of the two ring moons 1986U7 and 1986U8 is a major advance in our understanding of the structure of the Uranian rings and is in good agreement with theoretical predictions of how these narrow rings are kept from spreading out. Based on likely surface brightness properties, the moons are of roughly 2O- and 3O-km diameter, respectively. The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

  20. Generalized optical ABCD theorem and its application to the diffraction integral calculation.

    Science.gov (United States)

    Zhao, Chaoying; Tan, Weihan; Guo, Qizhi

    2004-11-01

    We generalize the transfer matrix ABCD theorem for paraxial rays of the optical system to skew rays propagated off axis, whether or not the system possesses rotational symmetry. Furthermore, we apply the generalized ABCD theorem to evaluate the diffraction integral matrix elements A-D expressed in terms of the angle eikonal T, with the primary aberrations included. Finally, analysis and numerical calculation are given for propagation of a light beam through the optical system in the case in which spherical aberration and coma are present.

  1. Prevention of infectious diseases in cat shelters: ABCD guidelines.

    Science.gov (United States)

    Möstl, Karin; Egberink, Herman; Addie, Diane; Frymus, Tadeusz; Boucraut-Baralon, Corine; Truyen, Uwe; Hartmann, Katrin; Lutz, Hans; Gruffydd-Jones, Tim; Radford, Alan D; Lloret, Albert; Pennisi, Maria Grazia; Hosie, Margaret J; Marsilio, Fulvio; Thiry, Etienne; Belák, Sándor; Horzinek, Marian C

    2013-07-01

    Recommendations are given in relation to infectious diseases in rescue shelters. The ABCD recognises that there is a wide variation in the design and management of shelters, and that these largely reflect local pressures. These guidelines are written with this diverse audience in mind; they point to the ideal, and also provide for some level of compromise where this ideal cannot immediately be attained. In addition consideration should be given to general requirements in order to optimise overall health and wellbeing of cats within the shelter. HOUSING: Compartmentalisation of the shelter into at least three individual sections (quarantine area for incoming cats, isolation facilities for sick or potentially infectious cats, and accommodation for clinically healthy, retrovirus-negative cats) can facilitate containment of a disease outbreak, should it occur. STANDARD OF CARE: Incoming cats should receive a full health check by a veterinary surgeon, should be dewormed and tested for retrovirus infections (feline leukaemia virus [FeLV] and/or feline immunodeficiency virus [FIV]) in regions with high prevalence and in shelters that allow contact between cats. Cats which are not rehomed should receive a regular veterinary check-up at intervals recommended by their veterinarian. Each cat should be vaccinated as soon as possible against feline panleukopenia virus (FPV), feline herpesvirus (FHV-1) and feline calicivirus (FCV) infections. HYGIENE: Adequate hygiene conditions should ensure that contact between shedders of infectious agents and susceptible animals is reduced as efficiently as possible by movement control, hygiene procedures of care workers, barrier nursing, cleaning and disinfection. STRESS REDUCTION: Stress reduction is important for overall health and for minimising the risk of recrudescence and exacerbation of infectious diseases. In general, a special effort should be made to rehome cats as soon as possible.

  2. Pericellular Griffonia simplicifolia I isolectin B4-binding ring structures in the dorsal root ganglia following peripheral nerve injury in rats.

    Science.gov (United States)

    Li, L; Zhou, X F

    2001-10-22

    Patients with a peripheral nerve injury often suffer from persistent chronic pain, but the underlying mechanism remains largely unknown. The persistent nature of the pain suggests injury-induced profound structural changes along the sensory pathways. In the present study, using the plant Griffonia simplicifolia I isolectin B4 (IB4) as a marker for nonpeptidergic small sensory neurons, we sought to examine whether these neurons sprout in the dorsal root ganglia (DRG) in response to peripheral nerve injury. The lumbar 5 (L5) spinal nerve was transected, and rats were allowed to survive for varying lengths of time before IB4 histology was performed. We found that a subpopulation of IB4-positive sensory neurons sprouted robustly after spinal nerve injury. Twelve weeks after spinal nerve injury, the IB4-positive ring structures became dramatic and encircled both large and small neurons in the DRG. The aberrant sprouting of small sensory neurons was also demonstrated by retrograde labeling. The processes of satellite cells surrounding large sensory neurons also became IB4 positive, and 87.8% of perineuronal IB4-positive ring structures intermingled and/or coexpressed with glial fibrillary acidic protein-positive satellite cells. Thus, the sprouting axons of IB4-positive neurons were intermingled with IB4-positive satellite cells, forming perineuronal ring structures surrounding large-diameter neurons. Ultrastructural examinations further confirmed that IB4-positive nerve terminals were entangled with satellite cells and IB4-negative unmyelinated sprouting fibers around sensory neurons. These studies have provided the first evidence that a subpopulation of IB4-binding small sensory neurons sprouts and forms perineuronal ring structures together with IB4-positive satellite cells in response to nerve injury. The significance of the sprouting of IB4-positive neurons remains to be determined. Copyright 2001 Wiley-Liss, Inc.

  3. ABCD2 identifies a subclass of peroxisomes in mouse adipose tissue

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaoxi, E-mail: xiaoxi.liu@uky.edu; Liu, Jingjing, E-mail: jingjing.liu0@gmail.com; Lester, Joshua D., E-mail: joshua.lester@uky.edu; Pijut, Sonja S., E-mail: srhee2@uky.edu; Graf, Gregory A., E-mail: Gregory.Graf@uky.edu

    2015-01-02

    Highlights: • We examined the D2 localization and the proteome of D2-containing compartment in mouse adipose tissue. • We confirmed the presence of D2 on a subcellular compartment that has typical structure as a microperoxisome. • We demonstrated the scarcity of peroxisome markers on D2-containing compartment. • The D2-containing compartment may be a subpopulation of peroxisome in mouse adipose tissue. • Proteomic data suggests potential association between D2-containing compartment and mitochondria and ER. - Abstract: ATP-binding cassette transporter D2 (D2) is an ABC half transporter that is thought to promote the transport of very long-chain fatty acyl-CoAs into peroxisomes. Both D2 and peroxisomes increase during adipogenesis. Although peroxisomes are essential to both catabolic and anabolic lipid metabolism, their function, and that of D2, in adipose tissues remain largely unknown. Here, we investigated the D2 localization and the proteome of D2-containing organelles, in adipose tissue. Centrifugation of mouse adipose homogenates generated a fraction enriched with D2, but deficient in peroxisome markers including catalase, PEX19, and ABCD3 (D3). Electron microscopic imaging of this fraction confirmed the presence of D2 protein on an organelle with a dense matrix and a diameter of ∼200 nm, the typical structure and size of a microperoxisome. D2 and PEX19 antibodies recognized distinct structures in mouse adipose. Immunoisolation of the D2-containing compartment confirmed the scarcity of PEX19 and proteomic profiling revealed the presence of proteins associated with peroxisome, endoplasmic reticulum (ER), and mitochondria. D2 is localized to a distinct class of peroxisomes that lack many peroxisome proteins, and may associate physically with mitochondria and the ER.

  4. Comparison of ab initio and DFT electronic structure methods for peptides containing an aromatic ring: effect of dispersion and BSSE.

    Science.gov (United States)

    Shields, Ashley E; van Mourik, Tanja

    2007-12-20

    We establish that routine B3LYP and MP2 methods give qualitatively wrong conformations for flexible organic systems containing pi systems and that recently developed methods can overcome the known inadequacies of these methods. This is illustrated for a molecule (a conformer of the Tyr-Gly dipeptide) for which B3LYP/6-31+G(d) and MP2/6-31+G(d) geometry optimizations yield strikingly different structures [Mol. Phys. 2006, 104, 559-570]: MP2 predicts a folded "closed-book" conformer with the glycine residue located above the tyrosine ring, whereas B3LYP predicts a more open conformation. By employing different levels of theory, including the local electron correlation methods LMP2 (local MP2) and LCCSD(T0) (local coupled cluster with single, double, and noniterative local triple excitations) and large basis sets (aug-cc-pVnZ, n=D, T, Q), it is shown that the folded MP2 minimum is an artifact caused by large intramolecular BSSE (basis set superposition error) effects in the MP2/6-31+G(d) calculations. The B3LYP functional gives the correct minimum, but the potential energy apparently rises too steeply when the glycine and tyrosine residues approach each other, presumably due to missing dispersion effects in the B3LYP calculations. The PWB6K and M05-2X functionals, designed to give good results for weak interactions, remedy this to some extent. The reduced BSSE in the LMP2 calculations leads to faster convergence with increasing basis set quality, and accurate results can be obtained with smaller basis sets as compared to canonical MP2. We propose LMP2 as a suitable method to study interactions with pi-electron clouds.

  5. A zebrafish model of X-linked adrenoleukodystrophy recapitulates key disease features and demonstrates a developmental requirement for abcd1 in oligodendrocyte patterning and myelination.

    Science.gov (United States)

    Strachan, Lauren R; Stevenson, Tamara J; Freshner, Briana; Keefe, Matthew D; Miranda Bowles, D; Bonkowsky, Joshua L

    2017-09-15

    X-linked adrenoleukodystrophy (ALD) is a devastating inherited neurodegenerative disease caused by defects in the ABCD1 gene and affecting peripheral and central nervous system myelin. ABCD1 encodes a peroxisomal transmembrane protein required for very long chain fatty acid (VLCFA) metabolism. We show that zebrafish (Danio rerio) Abcd1 is highly conserved at the amino acid level with human ABCD1, and during development is expressed in homologous regions including the central nervous system and adrenal glands. We used TALENs to generate five zebrafish abcd1 mutant allele lines introducing premature stop codons in exon 1, as well as obtained an abcd1 allele from the Zebrafish Mutation Project carrying a point mutation in a splice donor site. Similar to patients with ALD, zebrafish abcd1 mutants have elevated VLCFA levels. Interestingly, we found that CNS development of the abcd1 mutants is disrupted, with hypomyelination in the spinal cord, abnormal patterning and decreased numbers of oligodendrocytes, and increased cell death. By day of life five abcd1 mutants demonstrate impaired motor function, and overall survival to adulthood of heterozygous and homozygous mutants is decreased. Expression of human ABCD1 in oligodendrocytes rescued apoptosis in the abcd1 mutant. In summary, we have established a zebrafish model of ALD that recapitulates key features of human disease pathology and which reveals novel features of underlying disease pathogenesis. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Method proposing a slow light ring resonator structure coupled with a metal-dielectric-metal waveguide system based on plasmonic induced transparency.

    Science.gov (United States)

    Keleshtery, Mehdi Hassani; Kaatuzian, Hassan; Mir, Ali; Zandi, Ashkan

    2017-05-20

    We demonstrate the analogue of electromagnetically induced transparency (EIT) in a metal-dielectric-metal (MDM) plasmonic waveguide. Plasmonic induced transparency is a method similar to EIT. In this paper, a plasmonic MDM waveguide is proposed by using an ellipse shaped side-coupled ring resonator and simulated by finite difference time domain. Plasmonics as a new field of chip-scale technology is an interesting substrate, which is used to propose and numerically investigate a novel MDM structure. The aforementioned framework is a 2×2 plasmonic ring resonator, employing gold as a metal and polymethyl methacrylate as a dielectric. Simulations show that a transparent window is located at 1550 nm and signal wavelength is assumed to be 860 nm, which is the phenomenon of plasmonic induced transparency. The velocity of the plasmonic mode can be considerably slowed while propagating along the MDM bends. Our proposed configuration may thus be applied to storing and stopping light in plasmonic waveguide bends. This plasmonic waveguide system may find important applications for multichannel plasmonic filters, nano-scale optical switching, delay time devices, and slow-light devices in highly integrated optical circuits and networks. In comparison with our previous theoretical work based on circular shaped ring resonators, it is shown that ellipse shaped ring resonators demonstrate better specifications with a slow down factor estimated to be more than 30.

  7. Structure-Activity Studies Reveal the Oxazinone Ring Is a Determinant of Cytochrome P450 2B6 Activity Toward Efavirenz.

    Science.gov (United States)

    Cox, Philip M; Bumpus, Namandjé N

    2014-10-09

    Cytochrome P450 2B6 (CYP2B6) is primarily responsible for the metabolism of the anti-HIV drug efavirenz (EFV). We set out to explore the molecular basis for CYP2B6 activity toward EFV by examining the metabolism of eight EFV analogues. cDNA-expressed CYP2B6 formed monooxygenated metabolites from EFV analogues containing an intact oxazinone or oxazine ring, but not from analogues with a disrupted ring, suggesting this ring is important for metabolism of EFV by CYP2B6. Subsequent substrate depletion analysis of EFV and EFV analogues found to be CYP2B6 substrates revealed further differences between these CYP2B6 substrates. Compounds that were not found to be CYP2B6 substrates were still able to inhibit CYP2B6 activity toward a known substrate, bupropion, suggesting they do gain access to the CYP2B6 active site. Taken together, these data reveal structural characteristics of EFV, namely, the oxazinone ring, that are critical for CYP2B6 metabolism of compounds with the EFV chemical scaffold.

  8. Structural disorder and transformation in crystal growth: direct observation of ring-opening isomerization in a metal–organic solid solution

    Directory of Open Access Journals (Sweden)

    Ji-Jun Jiang

    2014-09-01

    Full Text Available A rare example is reported in which discrete Ag2L2 ring and (AgL∞ chain motifs [L = N,N′-bis(3-imidazol-1-yl-propyl-pyromellitic diimide] co-crystallize in the same crystal lattice with varying ratios and degrees of disorder. Crystal structures obtained from representative crystals reveal compatible packing arrangements of the cyclic and polymeric isomers within the crystal lattice, which enables them to co-exist within a crystalline solid solution. A feasible pathway for transformation between the isomers is suggested via facile rotation of the coordinating imidazolyl groups. This chemical system could provide a chance for direct observation of ring-opening isomerization at the crystal surface. Mass spectrometry and 1H NMR titration show a dynamic equilibrium between cyclic and oligomeric species in solution, and a potential crystallization process is suggested involving alignment of precursors directed by aromatic stacking interactions between pyromellitic diimide units, followed by ring-opening isomerization at the interface between the solid and the solution. Both cyclic and oligomeric species can act as precursors, with interconversion between them being facile due to a low energy barrier for rotation of the imidazole rings. Thermogravimetric analysis and variable-temperature powder X-ray diffraction indicate a transition to a different crystalline phase around 120°C, which is associated with loss of solvent from the crystal lattice.

  9. Topological rings

    CERN Document Server

    Warner, S

    1993-01-01

    This text brings the reader to the frontiers of current research in topological rings. The exercises illustrate many results and theorems while a comprehensive bibliography is also included. The book is aimed at those readers acquainted with some very basic point-set topology and algebra, as normally presented in semester courses at the beginning graduate level or even at the advanced undergraduate level. Familiarity with Hausdorff, metric, compact and locally compact spaces and basic properties of continuous functions, also with groups, rings, fields, vector spaces and modules, and with Zorn''s Lemma, is also expected.

  10. Ru(II) carbazole thiosemicarbazone complexes with four membered chelate ring: Synthesis, molecular structures and evaluation of biological activities.

    Science.gov (United States)

    Kumar, Ramasamy Raj; Ramesh, Rengan; Małecki, Jan Grzegorz

    2016-12-01

    Formation of ruthenium(II) complexes of the type [RuH(CO)(PPh3)2(L)] (where L=N-Substituted 9-ethyl carbazole thiosemicarbazone ligands) has been described from the reactions of [RuHCl(CO)(PPh3)3] and substituted carbazole thiosemicarbazones in 1:1 equivalent respectively. The composition of the complexes was established by elemental analysis, IR, NMR (1H ,13C and 31P) and UV-visible spectral methods. The solid state molecular structure of the ligands (L1-L3) and one of the complexes have been analysed by single-crystal X-ray studies, and found that the ruthenium(II) complexes possess a pseudo-octahedral geometry. The thiosemicarbazone ligand is coordinated to ruthenium as a monoanionic bidendate N,S-donor forming a four-membered chelate ring with a bite angle of 64.47(5)°. The stability of the complexes in aqueous medium was confirmed by UV-visible and ESI-Mass spectral studies. The DNA binding interactions of the complexes with Calf thymus DNA have been investigated by absorption, emission, elctrochemical, circular dichromism and viscosity measurements revealed that the complexes could interact with DNA via intercalation. Further, their protein binding ability was monitored by the quenching of tryptophan emission using bovine serum albumin (BSA) as a model protein. The alterations in the secondary structure of BSA by the complexes were confirmed with synchronous and three-dimensional fluorescence spectral studies. The ability of complexes to cleave BSA varies from 3>2>1 in the presence of activator like H2O2, as revealed from SDS-PAGE is consistent with their strong hydrophobic interaction with the protein. Free-radical scavenging ability of all the complexes were also carried out against a panel of radicals such as DPPH, NO, OH, O2- and reducing power assay under in vitro experimental conditions. The potential of complexes to act as anticancer agents is thoroughly examined on human cervical cancer cell line HeLa, Osteosarcoma cell line MG-63 and a normal mouse

  11. Comparative pharmacokinetics of amphotericin B after administration of a novel colloidal delivery system, ABCD, and a conventional formulation to rats.

    Science.gov (United States)

    Fielding, R M; Smith, P C; Wang, L H; Porter, J; Guo, L S

    1991-01-01

    The pharmacokinetics and tissue distribution of two amphotericin B dosage forms were compared in rats. A novel lipid-based colloidal delivery system for amphotericin B (Amphotericin B Colloidal Dispersion [ABCD]) which reduces the toxicity of amphotericin B in animals was compared with a conventional micellar formulation. Male Sprague-Dawley rats received a single intravenous injection of 1.0 mg of ABCD, 5.0 mg of ABCD, or 1.0 mg of micellar amphotericin B per kg. Plasma and tissue samples were obtained at 0.5 to 96 h after dosing and analyzed for amphotericin B by high-pressure liquid chromatography. Animals receiving ABCD demonstrated reduced peak levels in plasma, a three- to sevenfold reduction in amphotericin B delivery to the kidneys (the major target organ for toxicity), and prolonged residence time compared with those receiving the micellar formulation. In contrast, amphotericin B concentrations in the liver were two- to threefold higher with ABCD than with the micellar formulation: nearly 100% of the amphotericin B administered as ABCD was recovered from the liver 30 min after dosing. These results suggest that the colloidal particles of ABCD are taken up by the liver, which then acts as a reservoir of amphotericin B. PMID:1929263

  12. Electrochemical performance and structure evolution of core-shell nano-ring α-Fe{sub 2}O{sub 3}@Carbon anodes for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yan-Hui, E-mail: sunyanhui0102@163.com; Liu, Shan; Zhou, Feng-Chen; Nan, Jun-Min

    2016-12-30

    Core-shell nano-ring α-Fe{sub 2}O{sub 3}@Carbon (CSNR) composites with different carbon content (CSNR-5%C and CSNR-13%C) are synthesized using a hydrothermal method by controlling different amounts of glucose and α-Fe{sub 2}O{sub 3} nano-rings with further annealing. The CSNR electrodes exhibit much improved specific capacity, cycling stability and rate capability compared with that of bare nano-ring α-Fe{sub 2}O{sub 3} (BNR), which is attributed to the core-shell nano-ring structure of CSNR. The carbon shell in the inner and outer surface of CSNR composite can increase electron conductivity of the electrode and inhibit the volume change of α-Fe{sub 2}O{sub 3} during discharge/charge processes, and the nano-ring structure of CSNR can buffer the volume change too. The CSNR-5%C electrode shows super high initial discharge/charge capacities of 1570/1220 mAh g{sup −1} and retains 920/897 mAh g{sup −1} after 200 cycles at 500 mA g{sup −1} (0.5C). Even at 2000 mA g{sup −1} (2C), the electrode delivers the initial capacities of 1400/900 mAh g{sup −1}, and still maintains 630/610 mAh g{sup −1} after 200 cycles. The core-shell nano-rings opened during cycling and rebuilt a new flower-like structure consisting of α-Fe{sub 2}O{sub 3}@Carbon nano-sheets. The space among the nano-sheet networks can further buffer the volume expansion of α-Fe{sub 2}O{sub 3} and facilitate the transportation of electrons and Li{sup +} ions during the charge/discharge processes, which increases the capacity and rate capability of the electrode. It is the first time that the evolution of core-shell α-Fe{sub 2}O{sub 3}@Carbon changing to flower-like networks during lithiation/de-lithiation has been reported.

  13. Distances in generalized Double Rings and Degree Three Chordal Rings

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Riaz, Muhammad Tahir; Madsen, Ole Brun

    2005-01-01

    Generalized Double Rings (N2R) are compared to Degree Three Chordal Rings (CR) in terms of average distance, diameter, k-average distance and k-diameter. For each number of nodes, structures of each class are chosen to minimize diameter and average distance, an approach which is shown to result...

  14. Distances in Generalized Double Rings and Degree Three Chordal Rings

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Riaz, Muhammad Tahir; Madsen, Ole Brun

    2004-01-01

    Generalized Double Rings (N2R) are compared to Degree Three Chordal Rings (CR) in terms of average distance, diameter, k-average distance and k-diameter. For each number of nodes, structures of each class are chosen to minimize diameter and average distance, an approach which is shown to result...

  15. Ring interferometry

    CERN Document Server

    Malykin, Grigorii B; Zhurov, Alexei

    2013-01-01

    This monograph is devoted to the creation of a comprehensive formalism for quantitative description of polarized modes' linear interaction in modern single-mode optic fibers. The theory of random connections between polarized modes, developed in the monograph, allows calculations of the zero shift deviations for a fiber ring interferometer. The monograph addresses also the

  16. Manipulation of vortex rings for flow control

    Energy Technology Data Exchange (ETDEWEB)

    Toyoda, Kuniaki; Hiramoto, Riho [Mechanical Systems Engineering, Hokkaido Institute of Technology, Maeda 7-15-4-1, Teine-ku, Sapporo 006-855 (Japan)], E-mail: toyodahm@poppy.ocn.ne.jp

    2009-10-15

    This paper reviews the dynamics of vortex rings and the control of flow by the manipulation of vortex rings. Vortex rings play key roles in many flows; hence, the understanding of the dynamics of vortex rings is crucial for scientists and engineers dealing with flow phenomena. We describe the structures and motions of vortex rings in circular and noncircular jets, which are typical examples of flows evolving into vortex rings. For circular jets the mechanism of evolving, merging and breakdown of vortex rings is described, and for noncircular jets the dynamics of three-dimensional deformation and interaction of noncircular vortex rings under the effect of self- and mutual induction is discussed. The application of vortex-ring manipulation to the control of various flows is reviewed with successful examples, based on the relationship between the vortex ring dynamics and the flow properties. (invited paper)

  17. Effects of Agaricus lilaceps fairy rings on soil aggregation and microbial community structure in relation to growth stimulation of western wheatgrass (Pascopyrum smithii) in Eastern Montana rangeland.

    Science.gov (United States)

    Caesar-Tonthat, The Can; Espeland, Erin; Caesar, Anthony J; Sainju, Upendra M; Lartey, Robert T; Gaskin, John F

    2013-07-01

    Stimulation of plant productivity caused by Agaricus fairy rings has been reported, but little is known about the effects of these fungi on soil aggregation and the microbial community structure, particularly the communities that can bind soil particles. We studied three concentric zones of Agaricus lilaceps fairy rings in Eastern Montana that stimulate western wheatgrass (Pascopyrum smithii): outside the ring (OUT), inside the ring (IN), and stimulated zone adjacent to the fungal fruiting bodies (SZ) to determine (1) soil aggregate proportion and stability, (2) the microbial community composition and the N-acetyl-β-D-glucosaminidase activity associated with bulk soil at 0-15 cm depth, (3) the predominant culturable bacterial communities that can bind to soil adhering to wheatgrass roots, and (4) the stimulation of wheatgrass production. In bulk soil, macroaggregates (4.75-2.00 and 2.00-0.25 mm) and aggregate stability increased in SZ compared to IN and OUT. The high ratio of fungal to bacteria (fatty acid methyl ester) and N-acetyl-β-D-glucosaminidase activity in SZ compared to IN and OUT suggest high fungal biomass. A soil sedimentation assay performed on the predominant isolates from root-adhering soil indicated more soil-binding bacteria in SZ than IN and OUT; Pseudomonas fluorescens and Stenotrophomonas maltophilia isolates predominated in SZ, whereas Bacillus spp. isolates predominated in IN and OUT. This study suggests that growth stimulation of wheatgrass in A. lilaceps fairy rings may be attributed to the activity of the fungus by enhancing soil aggregation of bulk soil at 0-15 cm depth and influencing the amount and functionality of specific predominant microbial communities in the wheatgrass root-adhering soil.

  18. Can ABCD score predict the need for in-hospital intervention in patients with transient ischemic attacks?

    Science.gov (United States)

    Lou, Min; Safdar, Adnan; Edlow, Jonathan A; Caplan, Louis; Kumar, Sandeep; Schlaug, Gottfried; Searls, D Eric; Goddeau, Richard P; Selim, Magdy

    2010-05-18

    The ABCD(2) score is increasingly being used to triage patients with transient ischemic attack (TIA). Whether the score can predict the need for in-hospital intervention (IHI), other than initiation of antiplatelets and statins, is unknown. The ability of the ABCD(2) score to predict IHI would strengthen the rationale to use it as a decision-making tool. We thus conducted this study to investigate the relationship between the ABCD(2) score and IHI. We analyzed prospectively collected data from consecutive TIA patients over 12 months. We determined ABCD(2) upon admission and collected the results of in-hospital evaluation, treatments initiated during hospitalization, and follow-up status. We defined IHI as arterial revascularization or anticoagulation required during admission. We used chi-square for trend to examine the association between ABCD(2) and IHI. We studied 121 patients. Fourteen (12%) had small infarcts on diffusion magnetic resonance imaging; 38 (31%) had a new risk factor recognized during admission [hyperlipidemia (n = 9), hypertension (1), diabetes (1), carotid stenosis >/= 50% (16), other arterial occlusive lesions (7), and potential cardioembolic source (4)]. Their percentages increased with higher ABCD(2) scores. However, among 12 patients (10%) with IHI, ABCD(2) score categories were equally distributed (10% in 0-3, 9% in 4-5, and 10% in 6-7; p = 0.8). One patient (0.8%) worsened during hospitalization; none had a stroke during follow-up. Patients with an ABCD(2) score ABCD(2) score alone is not supported by our experience and requires further study.

  19. Can the ABCD Score be dichotomised to identify high-risk patients with transient ischaemic attack in the emergency department?

    Science.gov (United States)

    Bray, Janet E; Coughlan, Kelly; Bladin, Christopher

    2007-02-01

    Recent evidence shows a substantial short-term risk of ischaemic stroke after transient ischaemic attack (TIA). Identification of patients with TIA with a high short-term risk of stroke is now possible through the use of the "ABCD Score", which considers age, blood pressure, clinical features and duration of symptoms predictive of stroke. To evaluate the ability of dichotomising the ABCD Score to predict stroke at 7 and 90 days in a population with TIA presenting to an emergency department. A retrospective audit was conducted on all probable or definite TIAs presenting to the emergency department of a metropolitan hospital from July to December 2004. The ABCD Score was applied to 98 consecutive patients with TIA who were reviewed for subsequent strokes within 90 days. Patients obtaining an ABCD Score > or = 5 were considered to be at high risk for stroke. Dichotomising the ABCD Score categorised 48 (49%) patients with TIA at high risk for stroke (ABCD Score > or = 5). This high-risk group contained all four strokes that occurred within 7 days (sensitivity 100% (95% confidence interval (CI) 40% to 100%), specificity 53% (95% CI 43% to 63%), positive predictive value 8% (95% CI 3% to 21%) and negative predictive value 100% (95% CI 91% to 100%)), and six of seven occurring within 90 days (sensitivity 86% (95% CI 42% to 99%), specificity 54% (95% CI 43% to 64%), positive predictive value 12.5% (95% CI 5% to 26%) and negative predictive value 98% (95% CI 88% to 100%)). Removal of the "age" item from the ABCD Score halved the number of false-positive cases without changing its predictive value for stroke. In this retrospective analysis, dichotomising the ABCD Score was overinclusive but highly predictive in identifying patients with TIA at a high short-term risk of stroke. Use of the ABCD Score in the emergency care of patients with TIA is simple, efficient and provides a unique opportunity to prevent stroke in this population of patients.

  20. Novel mutation in ATP-binding domain of ABCD1 gene in ...

    Indian Academy of Sciences (India)

    MRI of the patient showed peritrigonal and cerebellar semioval white matter hypodensities and hyperintense areas (T2/fluid atten- uated inversion recovery) in bilateral cerebral white mat- ter, predominantly in parieto–occipital region. The molecu- lar analysis by direct sequencing of the ABCD1 gene showed the presence ...

  1. An A-B-C-D-E Worksheet for Promoting Beneficence When Considering Ethical Issues.

    Science.gov (United States)

    Sileo, Frank J.; Kopala, Mary

    1993-01-01

    Presents A-B-C-D-E worksheet prepared to promote beneficence when considering ethical issues. Notes that components of worksheet are derived from ethical principles and ethical decision-making models. Sees worksheet as making abstract concepts of decision-making models concrete and practical and as providing shorthand for remembering key elements…

  2. Melanoma recognition framework based on expert definition of ABCD for dermoscopic images.

    Science.gov (United States)

    Abbas, Qaisar; Emre Celebi, M; Garcia, Irene Fondón; Ahmad, Waqar

    2013-02-01

    Melanoma Recognition based on clinical ABCD rule is widely used for clinical diagnosis of pigmented skin lesions in dermoscopy images. However, the current computer-aided diagnostic (CAD) systems for classification between malignant and nevus lesions using the ABCD criteria are imperfect due to use of ineffective computerized techniques. In this study, a novel melanoma recognition system (MRS) is presented by focusing more on extracting features from the lesions using ABCD criteria. The complete MRS system consists of the following six major steps: transformation to the CIEL*a*b* color space, preprocessing to enhance the tumor region, black-frame and hair artifacts removal, tumor-area segmentation, quantification of feature using ABCD criteria and normalization, and finally feature selection and classification. The MRS system for melanoma-nevus lesions is tested on a total of 120 dermoscopic images. To test the performance of the MRS diagnostic classifier, the area under the receiver operating characteristics curve (AUC) is utilized. The proposed classifier achieved a sensitivity of 88.2%, specificity of 91.3%, and AUC of 0.880. The experimental results show that the proposed MRS system can accurately distinguish between malignant and benign lesions. The MRS technique is fully automatic and can easily integrate to an existing CAD system. To increase the classification accuracy of MRS, the CASH pattern recognition technique, visual inspection of dermatologist, contextual information from the patients, and the histopathological tests can be included to investigate the impact with this system. © 2012 John Wiley & Sons A/S.

  3. Special Features of the Advanced Loans Module of the ABCD Integrated Library System

    Science.gov (United States)

    de Smet, Egbert

    2011-01-01

    Purpose: The "advanced loans" module of the relatively new library software, ABCD, is an addition to the normal loans module and it offers a "generic transaction decision-making engine" functionality. The module requires extra installation effort and parameterisation, so this article aims to explain to the many potentially interested libraries,…

  4. Promoting Protective Factors for Young Adolescents: ABCD Parenting Young Adolescents Program Randomized Controlled Trial

    Science.gov (United States)

    Burke, Kylie; Brennan, Leah; Cann, Warren

    2012-01-01

    This study examined the efficacy of a program for parents of young adolescents combining behavioral family intervention with acceptance-based strategies. 180 parents were randomly allocated to a 6-session group ABCD Parenting Young Adolescent Program or wait-list condition. Completer analysis indicated parents in the intervention reported…

  5. Teaching How to Write Instructional Objectives to Pre-Service Language Teachers through the ABCD Model

    Science.gov (United States)

    Kiliçkaya, Ferit

    2016-01-01

    This paper presents the use of the ABCD model as a way to train teachers of English to write clear and specific objectives. It is stated here that most of the instructional objectives written by pre-service teachers are inadequately formulated. With this in mind, pre-service teachers (n = 46) were trained in writing instructional objectives…

  6. ABCD: Update of the 2009 guidelines on prevention and management of feline infectious diseases.

    Science.gov (United States)

    Horzinek, Marian C; Addie, Diane; Belák, Sándor; Boucraut-Baralon, Corine; Egberink, Herman; Frymus, Tadeusz; Gruffydd-Jones, Tim; Hartmann, Katrin; Hosie, Margaret J; Lloret, Albert; Lutz, Hans; Marsilio, Fulvio; Möstl, Karin; Pennisi, Maria Grazia; Radford, Alan D; Thiry, Etienne; Truyen, Uwe

    2013-07-01

    In this article, the ABCD guidelines published in the JFMS Special Issue of July 2009 (Volume 11, Issue 7, pages 527-620) are updated by including previously unavailable and novel information. For a better picture, the reader is advised to consult that issue before focusing on the novel features.

  7. ABCD syndrome is caused by a homozygous mutation in the EDNRB gene

    NARCIS (Netherlands)

    Verheij, JBGM; Kunze, J; Osinga, J; van Essen, AJ; Hofstra, RMW

    2002-01-01

    ABCD syndrome is an autosomal recessive syndrome characterized by albinism, black lock, cell migration disorder of the neurocytes of the gut (Hirschsprung disease [HSCR]), and deafness. This phenotype clearly overlaps with the features of the Shah-Waardenburg syndrome, comprising sensorineural

  8. Assessing appearance-related disturbances in HIV-infected men who have sex with men (MSM): psychometrics of the body change and distress questionnaire-short form (ABCD-SF).

    Science.gov (United States)

    Blashill, Aaron J; Wilson, Johannes M; Baker, Joshua S; Mayer, Kenneth H; Safren, Steven A

    2014-06-01

    Appearance-related disturbances are common among HIV-infected MSM; however, to date, there have been limited options in the valid assessment of this construct. The aim of the current study was to assess the structural, internal, and convergent validity of the assessment of body change distress questionnaire (ABCD) and its short version. Exploratory and confirmatory factor analyses indicated that both versions fit the data well. Four subfactors were revealed measuring the following body disturbance constructs: (1) negative affect about appearance, (2) HIV health-related outcomes and stigma, (3) eating and exercise confusion, and (4) ART non-adherence. The subfactors and total scores revealed bivariate associations with salient health outcomes, including depressive symptoms, HIV sexual transmission risk behaviors, and ART non-adherence. The ABCD and its short form, offer valid means to assess varied aspects of body image disturbance among HIV-infected MSM, and require modest participant burden.

  9. Assessing Appearance-Related Disturbances in HIV-Infected Men Who have Sex with Men (MSM): Psychometrics of the Body Change and Distress Questionnaire—Short Form (ABCD-SF)

    Science.gov (United States)

    Wilson, Johannes M.; Baker, Joshua S.; Mayer, Kenneth H.; Safren, Steven A.

    2013-01-01

    Appearance-related disturbances are common among HIV-infected MSM; however, to date, there have been limited options in the valid assessment of this construct. The aim of the current study was to assess the structural, internal, and convergent validity of the assessment of body change distress questionnaire (ABCD) and its short version. Exploratory and confirmatory factor analyses indicated that both versions fit the data well. Four sub-factors were revealed measuring the following body disturbance constructs: (1) negative affect about appearance, (2) HIV health-related outcomes and stigma, (3) eating and exercise confusion, and (4) ART non-adherence. The subfactors and total scores revealed bivariate associations with salient health outcomes, including depressive symptoms, HIV sexual transmission risk behaviors, and ART non-adherence. The ABCD and its short form, offer valid means to assess varied aspects of body image disturbance among HIV-infected MSM, and require modest participant burden. PMID:24057934

  10. Anonymous non-response analysis in the ABCD cohort study enabled by probabilistic record linkage.

    Science.gov (United States)

    Tromp, M; van Eijsden, M; Ravelli, A C J; Bonsel, G J

    2009-05-01

    Selective non-response is an important threat to study validity as it can lead to selection bias. The Amsterdam Born Children and their Development study (ABCD-study) is a large cohort study addressing the relationship between life style, psychological conditions, nutrition and sociodemographic background of pregnant women and their children's health. Possible selective non-response and selection bias in the ABCD-study were analysed using national perinatal registry data. ABCD-study data were linked with national perinatal registry data by probabilistic medical record linkage techniques. Differences in the prevalence of relevant risk factors (sociodemographic and care-related factors) and birth outcomes between respondents and non-respondents were tested using Pearson chi-squared tests. Selection bias (i.e. bias in the association between risk factors and specific outcomes) was analysed by regression analysis with and without adjustment for participation status. The ABCD non-respondents were significantly younger, more often non-western, and more often multiparae. Non-respondents entered antenatal care later, were more often under supervision of an obstetrician and had a spontaneous delivery more often. Non-response however, was not significantly associated with preterm birth (odds ratio 1.10; 95% CI 0.93, 1.29) or low birthweight (odds ratio 1.16; 95% CI 0.98, 1.37) after adjustment for sociodemographic risk factors. The associations found between risk factors and adverse pregnancy outcomes were similar for respondents and non-respondents. Anonymised record linkage of cohort study data with national registry data indicated that selective non-response was present in the ABCD-study, but selection bias was acceptably low and did not influence the main study questions.

  11. Streptococcus agalactiae capsule polymer length and attachment is determined by the proteins CpsABCD.

    Science.gov (United States)

    Toniolo, Chiara; Balducci, Evita; Romano, Maria Rosaria; Proietti, Daniela; Ferlenghi, Ilaria; Grandi, Guido; Berti, Francesco; Ros, Immaculada Margarit Y; Janulczyk, Robert

    2015-04-10

    The production of capsular polysaccharides (CPS) or secreted exopolysaccharides is ubiquitous in bacteria, and the Wzy pathway constitutes a prototypical mechanism to produce these structures. Despite the differences in polysaccharide composition among species, a group of proteins involved in this pathway is well conserved. Streptococcus agalactiae (group B Streptococcus; GBS) produces a CPS that represents the main virulence factor of the bacterium and is a prime target in current vaccine development. We used this human pathogen to investigate the roles and potential interdependencies of the conserved proteins CpsABCD encoded in the cps operon, by developing knock-out and functional mutant strains. The mutant strains were examined for CPS quantity, size, and attachment to the cell surface as well as CpsD phosphorylation. We observed that CpsB, -C, and -D compose a phosphoregulatory system where the CpsD autokinase phosphorylates its C-terminal tyrosines in a CpsC-dependent manner. These Tyr residues are also the target of the cognate CpsB phosphatase. An interaction between CpsD and CpsC was observed, and the phosphorylation state of CpsD influenced the subsequent action of CpsC. The CpsC extracellular domain appeared necessary for the production of high molecular weight polysaccharides by influencing CpsA-mediated attachment of the CPS to the bacterial cell surface. In conclusion, although having no impact on cps transcription or the synthesis of the basal repeating unit, we suggest that these proteins are fine-tuning the last steps of CPS biosynthesis (i.e. the balance between polymerization and attachment to the cell wall). © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. RING SYSTEM

    African Journals Online (AJOL)

    ); 0 “C1211; 30.13 ('BuP. o. J,.,_. = 12.2 1-11). @500 (OCH._,, dq,. J“. = 34.6. JR. = 15.8 H2). 124.39 (CF3. dq, JPF = 269.0, JR. = 9.7 Hz). 35.63 (PC. cl. .... The compound was prepared using the same technique from the boron ring [31 [2 g.

  13. On the role of large-scale, coherent structures (vortex rings) in the sound emission of jets

    Science.gov (United States)

    Sakao, F.

    1984-05-01

    The effect of vortex-axis inclination on the directivity of the sound emission from the inviscid interaction of a coaxial pair of ring vortices in an axisymmetric subsonic jet is investigated by means of model calculations, and the results are presented in a graph. The decrease in sound intensity at about 55 deg from the jet axis predicted by Kambe and Murakami (1979) is confirmed for all vortex-pair inclinations less than + or - 23.3 deg, and with a concentration of sound at jet-axis angles 30 deg or less is shown. Since these phenomena are not observed experimentally, it is concluded that the sound due to axisymmetric pairing of vortex rings is not a significant component of jet noise.

  14. Measurement of concentration and temperature using a fiber loop ring-down technique with core-offset structure

    Science.gov (United States)

    Wang, Fang; Lu, Heng; Wang, Xu; Liu, Yufang

    2018-03-01

    Fiber-loop ring-down spectroscopy (FLRDS) technique can be used for measurement by indirectly measuring the ring-down time. This is advantageous because it is free from fluctuations of the light source and has a high sensitivity. A novel sensing system for measuring the concentration and temperature based on the FLRDS technique and Mach-Zehnder interferometer (MZI) is proposed in this work. The intra-cavity losses were compensated, which depended on the erbium-doped fiber amplifier. The sensor head was a section of 4 cm single-mode fiber that was spliced into the fiber loop ring cavity in a core-offset way, and its characteristics were tested by experimenting with different solution concentrations and temperatures. The experimental results showed that the detection limit of this system is 0.0014 g/ml, in the range of 0.010-0.400 g/ml. In the temperature sensing experiment, when the temperature varied from 30-200 °C, a sensitivity of 1.83 μs/°C was achieved. This research demonstrated that the MZI-based FLRDS sensing system has a clear response to the solution and temperature; therefore, it provides a reference for the measurement of stress, pressure, curvature, and other physical quantities.

  15. Effect of origin conditions on the anatomical structure of the annual ring of Pinus sylvestris L. in the taiga zone

    Directory of Open Access Journals (Sweden)

    Kiсhshenko Ivan Tarasovich

    2014-11-01

    Full Text Available The studies were conducted in South Karelia (middle taiga subzone in 2006. Objects of study were the following kinds of pine forest: bilberry, cowberry and wild rosemary-bog moss ones. The investigation has shown that with the advancement of the tree in the forest canopy the annual growth ring of the trunk increases significantly. Thus, in the bilberry pine forest in the trees of the growth class I this index is higher than in the trees of the growth classes II-III and IV-V by 4 and 97 %, respectively. In the bilberry pine forest the percentage of the participation of late wood in the formation of growth ring in the dominant trees is by 6-9% less than that of the rest of the stand. The width of the early tracheid shells in the trees of the growth class I-III is by 22% more than in the overtopped ones in the bilberry pine forest. Annual ring width and latewood percentage in the pine forest of Hylocomium group is higher than in the wild rosemary – bog moss one by 41-50 and 7-35%, respectively. The maximal thickness of the late tracheid shells was observed in the cowberry pine forest (6.8-7.4 microns.

  16. Ground Movement in SSRL Ring

    Energy Technology Data Exchange (ETDEWEB)

    Sunikumar, Nikita; /UCLA /SLAC

    2011-08-25

    Users of the Stanford Synchrotron Radiation Lightsource (SSRL) are being affected by diurnal motion of the synchrotron's storage ring, which undergoes structural changes due to outdoor temperature fluctuations. In order to minimize the effects of diurnal temperature fluctuations, especially on the vertical motion of the ring floor, scientists at SSRL tried three approaches: painting the storage ring white, covering the asphalt in the middle of the ring with highly reflective Mylar and installing Mylar on a portion of the ring roof and walls. Vertical motion in the storage ring is measured by a Hydrostatic Leveling System (HLS), which calculates the relative height of water in a pipe that extends around the ring. The 24-hr amplitude of the floor motion was determined using spectral analysis of HLS data, and the ratio of this amplitude before and after each experiment was used to quantitatively determine the efficacy of each approach. The results of this analysis showed that the Mylar did not have any significant effect on floor motion, although the whitewash project did yield a reduction in overall HLS variation of 15 percent. However, further analysis showed that the reduction can largely be attributed to a few local changes rather than an overall reduction in floor motion around the ring. Future work will consist of identifying and selectively insulating these local regions in order to find the driving force behind diurnal floor motion in the storage ring.

  17. Relinkable Ring Signature

    Science.gov (United States)

    Suzuki, Koutarou; Hoshino, Fumitaka; Kobayashi, Tetsutaro

    In this paper, we propose the concept of a relinkable ring signature, which is a ring signature with ring reformation function, i.e., a signer can delegate ring reformation ability separately from signing ability to his/her proxy. The relinkable ring signature can be applicable to proxy ring reformation, anonymization of past-generated signature, or ring signature for dynamic group. We also propose a concrete relinkable ring signature scheme that uses pairing in the random oracle model.

  18. Histone deacetylase inhibitor upregulates peroxisomal fatty acid oxidation and inhibits apoptotic cell death in abcd1-deficient glial cells.

    Directory of Open Access Journals (Sweden)

    Jaspreet Singh

    Full Text Available In X-ALD, mutation/deletion of ALD gene (ABCD1 and the resultant very long chain fatty acid (VLCFA derangement has dramatically opposing effects in astrocytes and oligodendrocytes. While loss of Abcd1 in astrocytes produces a robust inflammatory response, the oligodendrocytes undergo cell death leading to demyelination in X-linked adrenoleukodystrophy (X-ALD. The mechanisms of these distinct pathways in the two cell types are not well understood. Here, we investigated the effects of Abcd1-knockdown and the subsequent alteration in VLCFA metabolism in human U87 astrocytes and rat B12 oligodendrocytes. Loss of Abcd1 inhibited peroxisomal β-oxidation activity and increased expression of VLCFA synthesizing enzymes, elongase of very long chain fatty acids (ELOVLs (1 and 3 in both cell types. However, higher induction of ELOVL's in Abcd1-deficient B12 oligodendrocytes than astrocytes suggests that ELOVL pathway may play a prominent role in oligodendrocytes in X-ALD. While astrocytes are able to maintain the cellular homeostasis of anti-apoptotic proteins, Abcd1-deletion in B12 oligodendrocytes downregulated the anti-apototic (Bcl-2 and Bcl-xL and cell survival (phospho-Erk1/2 proteins, and upregulated the pro-apoptotic proteins (Bad, Bim, Bax and Bid leading to cell loss. These observations provide insights into different cellular signaling mechanisms in response to Abcd1-deletion in two different cell types of CNS. The apoptotic responses were accompanied by activation of caspase-3 and caspase-9 suggesting the involvement of mitochondrial-caspase-9-dependent mechanism in Abcd1-deficient oligodendrocytes. Treatment with histone deacetylase (HDAC inhibitor suberoylanilide hydroxamic acid (SAHA corrected the VLCFA derangement both in vitro and in vivo, and inhibited the oligodendrocytes loss. These observations provide a proof-of principle that HDAC inhibitor SAHA may have a therapeutic potential for X-ALD.

  19. Interobserver agreement in ABCD scoring between non-stroke specialists and vascular neurologists following suspected TIA is only fair.

    LENUS (Irish Health Repository)

    Kinsella, Justin A

    2012-02-01

    The appropriateness of use and accuracy of age, blood pressure, clinical features and duration of symptoms (ABCD) scoring by non-stroke specialists while risk-stratifying patients with suspected transient ischaemic attack (TIA) are unknown. We reviewed all available ABCD data from referrals to a specialist neurovascular clinic. ABCD scoring was defined as \\'appropriate\\' in this study if an experienced vascular neurologist subsequently confirmed a clinical diagnosis of possible, probable or definite TIA, and \\'inappropriate\\' if the patient had an alternative diagnosis or stroke. Interobserver agreement between the referring physician and the neurologist was calculated. One hundred and four patients had completed ABCD referral proformas available for analysis. Forty-five (43%) were deemed appropriate, and 59 (57%) inappropriate. In the entire dataset, the neurologist agreed with the referring physician\\'s total ABCD score in only 42% of cases [kappa = 0.28]. The two most unreliable components of the scoring system were clinical features [kappa = 0.51], and duration of symptoms [kappa = 0.48]. ABCD scoring by non-stroke specialists is frequently inappropriate and inaccurate in routine clinical practice, emphasising the importance of urgent specialist assessment of suspected TIA patients.

  20. Interobserver agreement in ABCD scoring between non-stroke specialists and vascular neurologists following suspected TIA is only fair.

    Science.gov (United States)

    Kinsella, Justin A; Tobin, W Oliver; Cogan, Nicola; McCabe, Dominick J H

    2011-06-01

    The appropriateness of use and accuracy of age, blood pressure, clinical features and duration of symptoms (ABCD) scoring by non-stroke specialists while risk-stratifying patients with suspected transient ischaemic attack (TIA) are unknown. We reviewed all available ABCD data from referrals to a specialist neurovascular clinic. ABCD scoring was defined as 'appropriate' in this study if an experienced vascular neurologist subsequently confirmed a clinical diagnosis of possible, probable or definite TIA, and 'inappropriate' if the patient had an alternative diagnosis or stroke. Interobserver agreement between the referring physician and the neurologist was calculated. One hundred and four patients had completed ABCD referral proformas available for analysis. Forty-five (43%) were deemed appropriate, and 59 (57%) inappropriate. In the entire dataset, the neurologist agreed with the referring physician's total ABCD score in only 42% of cases [κ = 0.28]. The two most unreliable components of the scoring system were clinical features [κ = 0.51], and duration of symptoms [κ = 0.48]. ABCD scoring by non-stroke specialists is frequently inappropriate and inaccurate in routine clinical practice, emphasising the importance of urgent specialist assessment of suspected TIA patients.

  1. Boscovich force in spherical coordinates: some gravitational implications for deflection of light, Trojan orbits, Titius-Bode structures, ring structures and flat rotation rate of galaxies

    Science.gov (United States)

    Munera, Hector A.

    2015-08-01

    From philosophical considerations, Boscovich proposed around 1760 a unified force of nature. Boscovich’s force turns out to be a particular case of the novel solutions for the homogeneous wave equation in spherical coordinates found by the present author in the 1990s [Found. Phys. Lett. 10, 31-41 (1997)]. As noted by J. J. Thomson before Bohr’s quantum theory, Boscovich’s force exhibits quantization in energy and distance.For each quantum number, our non-harmonic functions of the first kind (NHF-1k) predict the existence of a discrete number of spherical surfaces in dynamical equilibrium (SSDE), leading to both Titius-Bode and ring structures. Predictions agree with observed Titius-Bode patterns in our planetary system, and in the moons of Mars, Jupiter, Uranus, Saturn, and Neptune. At distances beyond the quantum structure associated with SSDEs, for even NHF-1ks the force becomes Newton’s inverse-square law; however, odd NHF-1ks exhibit a non-zero limit as distance tends to infinity, which immediately explains the flat rotation rate of spiral galaxies without additional asumptions as dark matter or MOND models. The SSDEs provide the physical counterpart to the mathematical spheres that appear in the recent solution of the three-body problem and the orbits of Trojan moons [Suvakov & Dmitrasinovic, Phys. Rev. Lett. 110, 114301 (2013)]. The inner-most SSDE is a photon-sphere, but inside it there is a monotonously increasing repulsion, thus acting as a “white” hole; this could be relevant in the context of the contradictory appearance of a black and a white hole in the creation of black holes in the laboratory [Leonhard & Philbin ArXiv:0803.0669 5 March 2008]. Deflection of light does not occur at the SSDEs but at intermediate locations where gravitational attraction reaches a maximum. Calculation of deflection involves three non-Newtonian aspects: the force is not exactly Newton’s, the distance is larger than the radius of the physical surface, and

  2. Tree-ring anomalies in Toona ciliata

    OpenAIRE

    Heinrich, Ingo; Banks, John Charles Gripper

    2006-01-01

    New increment core samples of Toona ciliata collected in the Australian tropics and subtropics compared to already existing material from the Upper Kangaroo Valley, near Sydney exhibit distinct differences in tree-ring structures. This necessitated a closer examination of the wood anatomy, possible false rings and the species’ crossdating capacity in northeast Australia. During tree-ring analysis two growth anomalies (extensive zones of narrow and indistinct rings) and three types of false ri...

  3. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

    Ge, Xiaoqing

    2010-06-01

    Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.

  4. Some ISIS-Software History and Technical Background on the new FOSS Integrated Library System ABCD

    Directory of Open Access Journals (Sweden)

    Egbert de Smet

    2010-02-01

    Full Text Available While free and open source software is gaining momentum in library automation, it is still not a trivial event to launch a full-blown integrated library system (ILS, given today's high demands on such library systems. In this article we describe the ISIS-software origins of the newly launched ABCD-software for which there is a morethan-average interest in many parts of the libraries and information communities in the developing world. Many — especially younger — librarians in the West have never heard about ISIS, its relevance and its technological concepts, so we will try to shed some light on this in order for librarians to better judge the meaning of the ABCD software for international librarianship and — why not — perhaps even for their own purposes.

  5. The propagation of hypergeometric beams through an annular apertured paraxial ABCD optical system

    Science.gov (United States)

    Tang, Bin; Jiang, Chun; Zhu, Haibin; Zhou, Xin; Wang, Shuai

    2014-12-01

    By means of expanding the hard aperture function into a finite sum of complex Gaussian functions and based on the generalized Huygens-Fresnel diffraction integral, a novel approximate analytical expression of hypergeometric (HyG) beams passing through a paraxial ABCD optical system with an annular aperture is derived. The results could be reduced to the case of a circular aperture or a circular black screen. Some numerical simulations are also performed and illustrated for the propagation characteristics and focusing properties of a HyG beam through a paraxial ABCD optical system with an annular aperture. The results obtained from the approximate analytical formula provide more efficiency than the usual way of using diffraction integral formula directly.

  6. Synthesis of an ABCD-Type Phthalocyanine by Intramolecular Cyclization Reaction.

    Science.gov (United States)

    Chow, Sun Y S; Ng, Dennis K P

    2016-07-01

    Unsymmetrical phthalocyanines with a low symmetry can exhibit unique and intriguing properties that can facilitate their applications in certain disciplines. The synthesis of these compounds, however, has posed a great difficulty. A novel and unprecedented approach for phthalocyanine synthesis is reported that involves intramolecular cyclization of prelinked tetrakisphthalonitriles. By using this strategy, the first ABCD-type phthalocyanine has been prepared in 7.2% yield.

  7. Validating the ABCD(2) Score for predicting stroke risk after transient ischemic attack in the ED.

    Science.gov (United States)

    Ong, Marcus Eng Hock; Chan, Yiong Huak; Lin, Wan Ping; Chung, Wan Ling

    2010-01-01

    The aim of the study was to validate the use of the ABCD(2) score for the prediction of stroke after transient ischemic attack (TIA) in patients presenting to the emergency department (ED). The ABCD(2) scoring is based on 5 factors as follows: age of at least 60 years; blood pressure of at least 140/90 mm Hg; clinical features such as unilateral weakness and speech impairment alone; duration of at least 60 minutes or 10 to 59 minutes; and diabetes. The authors conducted a retrospective observational study of all patients presented to the ED for TIA, as diagnosed by the attending emergency physicians, for a 2-year period. Sensitivity, specificity, and negative predictive value (NPV) were calculated for risk of stroke at 2, 7, 30, and 90 days after presentation. From January 1, 2005, to December 31, 2006, there were 470 patients diagnosed with TIA at the ED. Mean age was 61.0 years (SD, 13.2), with 63.3% males. Age of at least 60 years, unilateral weakness, and duration of at least 60 minutes were found to be significant predictors of stroke at 2 days. An admission rule based on an ABCD(2) score of at least 4 showed sensitivity of 86.4% and NPV of 91.7% for stroke at 7 days. Admission based on a score of at least 3 showed sensitivity of 96.6% and NPV of 96.1%. Admission rate was 69.1% and. 83.6%, respectively. The ABCD(2) rule showed good sensitivity and NPV for stroke at 7 days. However, NPV was not 100%, and there would still be patients being discharged from the ED and returning with a stroke if this cutoff was implemented in our setting.

  8. Laparoscopic sleeve gastrectomy for type 2 diabetes mellitus: predicting the success by ABCD score.

    Science.gov (United States)

    Lee, Wei-Jei; Almulaifi, Abdullah; Tsou, Ju Juin; Ser, Kong-Han; Lee, Yi-Chih; Chen, Shu-Chun

    2015-01-01

    Laparoscopic sleeve gastrectomy (LSG) is becoming a primary bariatric surgery for obesity and related diseases. This study presents the outcome of LSG with regard to the remission of type 2 diabetes mellitus (T2 DM) and the usefulness of a grading system to categorize and predict outcome of T2 DM remission. A total of 157 patients with T2 DM (82 women and 75 men) with morbid obesity (mean body mass index 39.0±7.4 kg/m(2)) who underwent LSG from 2006 to 2013 were selected for the present study. The ABCD score is composed of the patient's age, body mass index, C-peptide level, and duration of T2 DM (yr). The remission of T2 DM after LSG was evaluated using the ABCD score. At 12 months after surgery, 85 of the patients had complete follow-up data. The weight loss was 26.5% and the mean HbA1c decreased from 8.1% to 6.1%. A significant number of patients had improvement in their glycemic control, including 45 (52.9%) patients who had complete remission (HbA1cABCD score than those who did not (7.3±1.7 versus 5.2±2.1, PABCD score were also at a higher rate of success in T2 DM remission (from 0% in score 0 to 100% in score 10). LSG is an effective and well-tolerated procedure for achieving weight loss and T2 DM remission. The ABCD score, a simple multidimensional grading system, can predict the success of T2 DM treatment by LSG. Copyright © 2015 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

  9. The ABCD matrix for parabolic reflectors and its application to astigmatism free four-mirror cavities

    Science.gov (United States)

    Dupraz, K.; Cassou, K.; Martens, A.; Zomer, F.

    2015-10-01

    The ABCD matrix for parabolic reflectors is derived for any incident angles. It is used in numerical studies of four-mirror cavities composed of two flat and two parabolic mirrors. Constraints related to laser beam injection efficiency, optical stability, cavity-mode, beam-waist size and high stacking power are satisfied. A dedicated alignment procedure leading to stigmatic cavity-modes is employed to overcome issues related to the optical alignment of parabolic reflectors.

  10. The significance of compression wood in restoration of the leader in Pinus sihestris L. damaged by moose (Alces alces. II. Structure of growth rings in regenerating stems in relation to juvenile wood formation

    Directory of Open Access Journals (Sweden)

    B. A. Molski

    2015-01-01

    Full Text Available The corewood of pine ds very prone to compression wood formation, this changing the whole pattern of the tree ring structure and the siz.es of early and late wood. Compression wood always increases the formation of late wood at the expense of early wood. Tree rings with compression wood are generally wider than those without it, but there occur also tree rings wihout compression wood wider than those in which it is present, formed in the same year and in the same tree.

  11. Biomechanics of Corneal Ring Implants

    Science.gov (United States)

    2015-01-01

    Purpose: To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus. Methods: The spherical dome model considers the inhomogeneity of the tunica of the eye, dimensions of the cornea, lamellar structure of the corneal stroma, and asphericity of the cornea. It is used in this study for calculating a strengthening factor sf for the characterization of different ring-shaped corneal implant designs. The strengthening factor is a measure of the amount of strengthening of the cornea induced by the implant. Results: For ring segments and incomplete rings, sf = 1.0, which indicates that these implants are not able to strengthen the cornea. The intracorneal continuous complete ring (MyoRing) has a strengthening factor of up to sf = 3.2. The MyoRing is, therefore, able to strengthen the cornea significantly. Conclusions: The result of the presented biomechanical analysis of different ring-shaped corneal implant designs can explain the different postoperative clinical results of different implant types in myopia and keratoconus. PMID:26312619

  12. Biomechanics of Corneal Ring Implants.

    Science.gov (United States)

    Daxer, Albert

    2015-11-01

    To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus. The spherical dome model considers the inhomogeneity of the tunica of the eye, dimensions of the cornea, lamellar structure of the corneal stroma, and asphericity of the cornea. It is used in this study for calculating a strengthening factor sf for the characterization of different ring-shaped corneal implant designs. The strengthening factor is a measure of the amount of strengthening of the cornea induced by the implant. For ring segments and incomplete rings, sf = 1.0, which indicates that these implants are not able to strengthen the cornea. The intracorneal continuous complete ring (MyoRing) has a strengthening factor of up to sf = 3.2. The MyoRing is, therefore, able to strengthen the cornea significantly. The result of the presented biomechanical analysis of different ring-shaped corneal implant designs can explain the different postoperative clinical results of different implant types in myopia and keratoconus.

  13. The ABCD(2) Score is Highly Predictive of Stroke in Minor Ischemic Stroke Patients.

    Science.gov (United States)

    Ghandehari, Kavian; Ahmadi, Fahimeh; Ebrahimzadeh, Saeed; Shariatinezhad, Keyvan; Ghandehari, Kosar

    2012-06-01

    Stroke risk prediction scores have been designed to stratify risk of recurrent cerebrovascular events in transient ischemic attack (TIA) and minor ischemic stroke (MIS) patients. Consecutive TIA or MIS patients referred to Ghaem Hospital, Mashhad were enrolled in a prospective cohort study during 2010-2011. Only TIA or MIS patients presenting within 24 h from the onset of symptoms were recruited. MIS was considered as ischemic stroke with NIHSS ABCD(2) scoring system for recurrent stroke or TIA was quantified by the area under the cure (AUC) using the c statistics. Three hundred ninety-three TIA patients (238 males, 155 females) and 118 MIS patients (77 males, 41 females) were enrolled in the study. One hundred seventeen strokes (23.2%), 99 TIA (19.6%), and 11 vascular death (2.2%) occurred within 3 months postevent in the whole of our 511 patients with minor ischemic events. The ABCD(2) score had a weak predictive value for 3 months and 3 days recurrent stroke in our TIA patients (AUC = 0.599, AUC = 0.591), but a high predictive value for 3 months and 3 days recurrent stroke in our MIS patients (AUC = 0.727, AUC = 0.728), respectively. The ABCD(2) score is highly predictive of short-term recurrent stroke in MIS patients but not TIA cases, despite its creation for TIA cohorts.

  14. First description of multivalent ring structures in eutherian mammalian meiosis: new chromosomal characterization of Cormura brevirostris (Emballonuridae, Chiroptera).

    Science.gov (United States)

    de Araújo, Ramon Everton Ferreira; Nagamachi, Cleusa Yoshiko; da Costa, Marlyson Jeremias Rodrigues; Noronha, Renata Coelho Rodrigues; Rodrigues, Luís Reginaldo Ribeiro; Pieczarka, Julio César

    2016-08-01

    Twelve specimens of the bat Cormura brevirostris (Emballonuridae: Chiroptera) were collected from four localities in the Brazilian Amazon region and analyzed by classical and molecular cytogenetics. The diploid number and autosomal fundamental number were as previously reported (2n = 22 and FNa = 40, respectively). Fluorescence in situ hybridization using rDNA probes and silver nitrate technique demonstrated the presence of two NOR sites and the presence of internal telomeric sequences at pericentromeric regions of all chromosomes with exception of Y. Based on meiotic studies and chromosome banding we suggest that the sex chromosome pair of C. brevirostris was equivocally identified as it appears in the literature. Meiotic analysis demonstrated that at diplotene-diakinesis the cells had a ring conformation involving four chromosome pairs. This suggests the occurrence of multiple reciprocal translocations among these chromosomes, which is a very rare phenomenon in vertebrates, and has never been described in Eutheria.

  15. Preferential expression of mutant ABCD1 allele is common in adrenoleukodystrophy female carriers but unrelated to clinical symptoms

    Directory of Open Access Journals (Sweden)

    Salsano Ettore

    2012-01-01

    Full Text Available Abstract Background Approximately 20% of adrenoleukodystrophy (X-ALD female carriers may develop clinical manifestations, typically consisting of progressive spastic gait, sensory deficits and bladder dysfunctions. A skewing in X Chromosome Inactivation (XCI, leading to the preferential expression of the X chromosome carrying the mutant ABCD1 allele, has been proposed as a mechanism influencing X-linked adrenoleukodystrophy (X-ALD carrier phenotype, but reported data so far are conflicting. Methods To shed light into this topic we assessed the XCI pattern in peripheral blood mononuclear cells (PBMCs of 30 X-ALD carriers. Since a frequent problem with XCI studies is the underestimation of skewing due to an incomplete sample digestion by restriction enzymes, leading to variable results, we developed a pyrosequencing assay to identify samples completely digested, on which to perform the XCI assay. Pyrosequencing was also used to quantify ABCD1 allele-specific expression. Moreover, very long-chain fatty acid (VLCFA levels were determined in the same patients. Results We found severely (≥90:10 or moderately (≥75:25 skewed XCI in 23 out of 30 (77% X-ALD carriers and proved that preferential XCI is mainly associated with the preferential expression of the mutant ABCD1 allele, irrespective of the manifestation of symptoms. The expression of mutant ABCD1 allele also correlates with plasma VLCFA concentrations. Conclusions Our results indicate that preferential XCI leads to the favored expression of the mutant ABCD1 allele. This emerges as a general phenomenon in X-ALD carriers not related to the presence of symptoms. Our data support the postulated growth advantage of cells with the preferential expression of the mutant ABCD1 allele, but argue against the use of XCI pattern, ABCD1 allele-specific expression pattern and VLCFA plasma concentration as biomarkers to predict the development of symptoms in X-ALD carriers.

  16. Preferential expression of mutant ABCD1 allele is common in adrenoleukodystrophy female carriers but unrelated to clinical symptoms

    Science.gov (United States)

    2012-01-01

    Background Approximately 20% of adrenoleukodystrophy (X-ALD) female carriers may develop clinical manifestations, typically consisting of progressive spastic gait, sensory deficits and bladder dysfunctions. A skewing in X Chromosome Inactivation (XCI), leading to the preferential expression of the X chromosome carrying the mutant ABCD1 allele, has been proposed as a mechanism influencing X-linked adrenoleukodystrophy (X-ALD) carrier phenotype, but reported data so far are conflicting. Methods To shed light into this topic we assessed the XCI pattern in peripheral blood mononuclear cells (PBMCs) of 30 X-ALD carriers. Since a frequent problem with XCI studies is the underestimation of skewing due to an incomplete sample digestion by restriction enzymes, leading to variable results, we developed a pyrosequencing assay to identify samples completely digested, on which to perform the XCI assay. Pyrosequencing was also used to quantify ABCD1 allele-specific expression. Moreover, very long-chain fatty acid (VLCFA) levels were determined in the same patients. Results We found severely (≥90:10) or moderately (≥75:25) skewed XCI in 23 out of 30 (77%) X-ALD carriers and proved that preferential XCI is mainly associated with the preferential expression of the mutant ABCD1 allele, irrespective of the manifestation of symptoms. The expression of mutant ABCD1 allele also correlates with plasma VLCFA concentrations. Conclusions Our results indicate that preferential XCI leads to the favored expression of the mutant ABCD1 allele. This emerges as a general phenomenon in X-ALD carriers not related to the presence of symptoms. Our data support the postulated growth advantage of cells with the preferential expression of the mutant ABCD1 allele, but argue against the use of XCI pattern, ABCD1 allele-specific expression pattern and VLCFA plasma concentration as biomarkers to predict the development of symptoms in X-ALD carriers. PMID:22280810

  17. Frequent inaccuracies in ABCD(2) scoring in non-stroke specialists' referrals to a daily Rapid Access Stroke Prevention service.

    LENUS (Irish Health Repository)

    Bradley, David

    2013-09-15

    The \\'accuracy\\' of age, blood pressure, clinical features, duration and diabetes (ABCD(2)) scoring by non-stroke specialists referring patients to a daily Rapid Access Stroke Prevention (RASP) service is unclear, as is the accuracy of ABCD(2) scoring by trainee residents. In this prospective study, referrals were classified as \\'confirmed TIAs\\' if the stroke specialist confirmed a clinical diagnosis of possible, probable or definite TIA, and \\'non-TIAs\\' if patients had a TIA mimic or completed stroke. ABCD(2) scores from referring physicians were compared with scores by experienced stroke specialists and neurology\\/geriatric medicine residents at a daily RASP clinic; inter-observer agreement was examined. Data from 101 referrals were analysed (mean age=60.0years, 58% male). The median interval between referral and clinic assessment was 1day. Of 101 referrals, 52 (52%) were \\'non-TIAs\\': 45 (86%) of 52 were \\'TIA mimics\\' and 7 (14%) of 52 were completed strokes. There was only \\'fair\\' agreement in total ABCD(2) scoring between referring physicians and stroke specialists (κ=0.37). Agreement was \\'excellent\\' between residents and stroke specialists (κ=0.91). Twenty of 29 patients scored as \\'moderate to high risk\\' (score 4-6) by stroke specialists were scored \\'low risk\\' (score 0-3) by referring physicians. ABCD(2) scoring by referring doctors is frequently inaccurate, with a tendency to underestimate stroke risk. These findings emphasise the importance of urgent specialist assessment of suspected TIA patients, and that ABCD(2) scores by non-stroke specialists cannot be relied upon in isolation to risk-stratify patients. Inter-observer agreement in ABCD(2) scoring was \\'excellent\\' between residents and stroke specialists, indicating short-term training may improve accuracy.

  18. ¿Sirve la escala ABCD2 del AIT para predecir y prevenir Ictus?

    Directory of Open Access Journals (Sweden)

    Laura Castelo Corral

    2015-09-01

    Resultados: Incluimos 172 pacientes ( edad media 71 años, 51% mujeres con un nuevo diagnostico de AIT. La puntuación media de la escala ABCD2 fue de 4.2 ± 1.4. Se produjeron 12 nuevos AIT, 21 Ictus no fatales y 3 ictus fatales durante el seguimiento. La mortalidad intrahospitalaria fue del 1.7% y la total durante el seguimiento de 1 año del 12 %. Una puntuación en la escala de ABCD2 de ≥ 4 tenia una sensibilidad del 88% y del 82% para predecir un ictus a los 7 y 30 días respectivamente, con una pobre especificidad del 30%.El valor predictivo negativo a 7 dias fue del 98%. Una puntuación ABCD2 ≥ 4 no tuvo valor predictivo significativo de ictus a los 7 días (hazard ratio [HR], 3.49; 95%CI, 0.42 to 27.93 ni a 30 días (HR, 1.97; 95%CI, 0.43 to 9.13. Como componente individual, solo la diabetes predijo la probabilidad de desarrollar un ictus en la primera semana (HR, 5.47; 95%IC 1.43 to 20.95 y durante el primer mes (HR, 3.60; 95%IC 1.08 to 12. Conclusiones: El poder discriminativo de la escala ABCD2 no ayuda a tomar decisiones de tratamiento salvo por su valor predictivo negativo del 98%. Solo la variable diabetes de la escala se asocio con una probabilidad relevante de tener un ictus.Probablemente cualquier tipo de presentación de AIT justifica la búsqueda rápida de la etiologia subyacente. Consideramos que en el AIT, independientemente de la escala ABCD2 , se debe realizar en menos de 24 horas un TAC cerebral, ECG, e imagen de carótida, mientras al mismo tiempo se inicia tratamiento preventivo urgente.

  19. Biomechanics of Corneal Ring Implants

    OpenAIRE

    Daxer, Albert

    2015-01-01

    Purpose: To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus. Methods: The spherical dome model considers the inhomogeneity of the tunica of the eye, dimensions of the cornea, lamellar structure of the corneal stroma, and asphericity of the cornea. It is used in this study for calculating a strengthening factor sf for the characterization of different ring-shaped corneal implant de...

  20. Beam instability induced by rf deflectors in the combiner ring of the CLIC test facility and mitigation by damped deflecting structures

    CERN Document Server

    Alesini, D; Biscari, C; Ghigo, A; Corsini, R

    2011-01-01

    In the CTF3 (CLIC test facility 3) run of November 2007, a vertical beam instability has been found in the combiner ring during operation. After a careful analysis, the source of the instability has been identified in the vertical deflecting modes trapped in the rf deflectors and excited by the beam passage. A dedicated tracking code that includes the induced transverse wakefield and the multibunch multipassage effects has been written and the results of the beam dynamics analysis are presented in the paper. The mechanism of the instability was similar to the beam breakup in a linear accelerator or in an energy recovery linac. The results of the code allowed identifying the main key parameters driving such instability and allowed finding the main knobs to mitigate it. To completely suppress such beam instability, two new rf deflectors have been designed, constructed, and installed in the ring. In the new structures the frequency separation between the vertical and horizontal deflecting modes has been increase...

  1. Can the ABCD Score be dichotomised to identify high‐risk patients with transient ischaemic attack in the emergency department?

    Science.gov (United States)

    Bray, Janet E; Coughlan, Kelly; Bladin, Christopher

    2007-01-01

    Background Recent evidence shows a substantial short‐term risk of ischaemic stroke after transient ischaemic attack (TIA). Identification of patients with TIA with a high short‐term risk of stroke is now possible through the use of the “ABCD Score”, which considers age, blood pressure, clinical features and duration of symptoms predictive of stroke. Aim To evaluate the ability of dichotomising the ABCD Score to predict stroke at 7 and 90 days in a population with TIA presenting to an emergency department. Methods A retrospective audit was conducted on all probable or definite TIAs presenting to the emergency department of a metropolitan hospital from July to December 2004. The ABCD Score was applied to 98 consecutive patients with TIA who were reviewed for subsequent strokes within 90 days. Patients obtaining an ABCD Score ⩾5 were considered to be at high risk for stroke. Results Dichotomising the ABCD Score categorised 48 (49%) patients with TIA at high risk for stroke (ABCD Score ⩾5). This high‐risk group contained all four strokes that occurred within 7 days (sensitivity 100% (95% confidence interval (CI) 40% to 100%), specificity 53% (95% CI 43% to 63%), positive predictive value 8% (95% CI 3% to 21%) and negative predictive value 100% (95% CI 91% to 100%)), and six of seven occurring within 90 days (sensitivity 86% (95% CI 42% to 99%), specificity 54% (95% CI 43% to 64%), positive predictive value 12.5% (95% CI 5% to 26%) and negative predictive value 98% (95% CI 88% to 100%)). Removal of the “age” item from the ABCD Score halved the number of false‐positive cases without changing its predictive value for stroke. Conclusion In this retrospective analysis, dichotomising the ABCD Score was overinclusive but highly predictive in identifying patients with TIA at a high short‐term risk of stroke. Use of the ABCD Score in the emergency care of patients with TIA is simple, efficient and provides a unique opportunity to prevent stroke in

  2. Biomedical ethics and clinical oversight in multisite observational neuroimaging studies with children and adolescents: The ABCD experience.

    Science.gov (United States)

    Clark, Duncan B; Fisher, Celia B; Bookheimer, Susan; Brown, Sandra A; Evans, John H; Hopfer, Christian; Hudziak, James; Montoya, Ivan; Murray, Margaret; Pfefferbaum, Adolf; Yurgelun-Todd, Deborah

    2017-06-28

    Observational neuroimaging studies with children and adolescents may identify neurological anomalies and other clinically relevant findings. Planning for the management of this information involves ethical considerations that may influence informed consent, confidentiality, and communication with participants about assessment results. Biomedical ethics principles include respect for autonomy, beneficence, non-maleficence, and justice. Each project presents unique challenges. The Adolescent Brain and Cognitive Development study (ABCD) collaborators have systematically developed recommendations with written guidelines for identifying and responding to potential risks that adhere to biomedical ethics principles. To illustrate, we will review the ABCD approach to three areas: (1) hazardous substance use; (2) neurological anomalies; and (3) imminent potential for self-harm or harm to others. Each ABCD site is responsible for implementing procedures consistent with these guidelines in accordance with their Institutional Review Board approved protocols, state regulations, and local resources. To assure that each site has related plans and resources in place, site emergency procedures manuals have been developed, documented and reviewed for adherence to ABCD guidelines. This article will describe the principles and process used to develop these ABCD bioethics and medical oversight guidelines, the concerns and options considered, and the resulting approaches advised to sites. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Value of ABCD2-F in Predicting Cerebral Ischemic Attacks: Three Months Follow-Up after the Primary Attack

    Directory of Open Access Journals (Sweden)

    Mojtaba Chardoli

    2016-06-01

    Full Text Available Cerebrovascular attack (CVA and transient ischemic attack (TIA are major causes of emergency department visits around the globe. A significant number of these patients may experience repeat attacks if left untreated. Several risk stratifying scoring systems have been developed in recent years to point out the high risk patients. ABCD2 is based on age, blood pressure, clinical status, diabetes mellitus, and duration of symptoms and is used commonly for this purpose. In this study, we were to enhance its sensitivity and specificity with the addition of another criterion namely atrial fibrillation and making ABCD2-F. A prospective study in two hospitals was performed and 138 patients diagnosed with TIA/CVA were enrolled. Demographic, clinical, and paraclinical data of all patients were registered. All patients were followed for three months for any sign or symptom of a recurrent ischemic attack. Recurrent ischemic attacks happened in 9.4% of the patients. None of the criteria of ABCD2-F was associated with higher chance of ischemic attacks. Similarly, ABCD2-F was not different between patients with or without repeat cerebral ischemia. The addition of atrial fibrillation to ABCD2 did not enhance the accuracy of this scoring system to detect patients high risk for repeat cerebral ischemia. More studies in the future to improve sensitivity and specificity of this test are warranted.

  4. Analysis of MADS-Box Gene Family Reveals Conservation in Floral Organ ABCDE Model of Moso Bamboo (Phyllostachys edulis

    Directory of Open Access Journals (Sweden)

    Zhanchao Cheng

    2017-05-01

    Full Text Available Mini chromosome maintenance 1, agamous, deficiens, and serum response factor (MADS-box genes are transcription factors which play fundamental roles in flower development and regulation of floral organ identity. However, till date, identification and functions of MADS-box genes remain largely unclear in Phyllostachys edulis. In view of this, we performed a whole-genome survey and identified 34 MADS-box genes in P. edulis, and based on phylogeny, they were classified as MIKCC, MIKC∗, Mα, and Mβ. The detailed analysis about gene structure and motifs, phylogenetic classification, comparison of gene divergence and duplication are provided. Interestingly, expression patterns for most genes were found similar to those of Arabidopsis and rice, indicating that the well-established ABCDE model can be applied to P. edulis. Moreover, we overexpressed PheMADS15, an AP1-like gene, in Arabidopsis, and found that the transgenic plants have early flowering phenotype, suggesting that PheMADS15 might be a regulator of flowering transition in P. edulis. Taken together, this study provides not only insightful comprehension but also useful information for understanding the functions of MADS-box genes in P. edulis.

  5. Population-based study of ABCD2 score, carotid stenosis, and atrial fibrillation for early stroke prediction after transient ischemic attack: the North Dublin TIA study.

    LENUS (Irish Health Repository)

    Sheehan, Orla C

    2010-05-01

    Transient ischemic attack (TIA) etiologic data and the ABCD(2) score may improve early stroke risk prediction, but studies are required in population-based cohorts. We investigated the external validity of the ABCD(2) score, carotid stenosis, and atrial fibrillation for prediction of early recurrent stroke after TIA.

  6. Contiguous Deletion of the X-Linked Adrenoleukodystrophy Gene (ABCD1) and DXS1357E: A Novel Neonatal Phenotype Similar to Peroxisomal Biogenesis Disorders

    Science.gov (United States)

    Corzo, Deyanira; Gibson, William; Johnson, Kisha; Mitchell, Grant; LePage, Guy; Cox, Gerald F.; Casey, Robin; Zeiss, Carolyn; Tyson, Heidi; Cutting, Garry R.; Raymond, Gerald V.; Smith, Kirby D.; Watkins, Paul A.; Moser, Ann B.; Moser, Hugo W.; Steinberg, Steven J.

    2002-01-01

    X-linked adrenoleukodystrophy (X-ALD) results from mutations in ABCD1. ABCD1 resides on Xq28 and encodes an integral peroxisomal membrane protein (ALD protein [ALDP]) that is of unknown function and that belongs to the ATP-binding cassette–transporter superfamily. Individuals with ABCD1 mutations accumulate very-long-chain fatty acids (VLCFA) (carbon length >22). Childhood cerebral X-ALD is the most devastating form of the disease. These children have the earliest onset (age 7.2 ± 1.7 years) among the clinical phenotypes for ABCD1 mutations, but onset does not occur at syndromes and individuals with ABCD1 mutations, on the basis of the clinical presentation and measurement of other biochemical markers. We have identified three newborn boys who had clinical symptoms and initial biochemical results consistent with PBD or SED. In further study, however, we showed that they lacked ALDP, and we identified deletions that extended into the promoter region of ABCD1 and the neighboring gene, DXS1357E. Mutations in DXS1357E and the ABCD1 promoter region have not been described previously. We propose that the term “contiguous ABCD1 DXS1357E deletion syndrome” (CADDS) be used to identify this new contiguous-gene syndrome. The three patients with CADDS who are described here have important implications for genetic counseling, because individuals with CADDS may previously have been misdiagnosed as having an autosomal recessive PBD or SED PMID:11992258

  7. Superiority of a cognitive education with photographs over ABCD criteria in the education of the general population to the early detection of melanoma: a randomized study.

    Science.gov (United States)

    Girardi, Sophie; Gaudy, Caroline; Gouvernet, Joanny; Teston, Jacques; Richard, Marie Aleth; Grob, Jean-Jacques

    2006-05-01

    Most education campaigns for melanoma (MM) detection in the general population have used the "ABCD" algorithm, although recognition of objects in the real life is based on a holistic image recognition rather than on analytic criteria. The objective was to compare analytic (ABCD) and cognitive (photographs) strategies for teaching self-recognition of MM. A prospective 4-arm stratified randomized trial in 255 individuals compared 3 realistic educative interventions by leaflets: 1) ABCD algorithm ("ABCD"), 2) a set of photographs chosen to stimulate recognition of MM among benign pigmented lesions ("Cog"), 3) photographs + explanations ("Cog-Ex" arm) and 4) no intervention ("NI"). A 40-slides test was performed before intervention (T0), 1 week after (T1) and after induction of anxiety (T2). In the "ABCD" arm, sensitivity slightly improved (80 to 83.8%, p = 0.04), but specificity dropped from 65.1 to 56.3% (p ABCD" arm (65.1 to 44.1%, p ABCD" message alone does not seem efficacious and is even worse in the context of anxiety, whereas a quick look at a few photographs is sufficient to improve the ability of the laymen to recognize a MM just by optimizing their spontaneous image recognition capacities. Education by photographs is a realistic strategy which should replace or complete "ABCD" message in the campaigns for self-detection of MM. 2005 Wiley-Liss, Inc.

  8. Structure of 1,5-benzodiazepinones in the solid state and in solution: Effect of the fluorination in the six-membered ring

    Directory of Open Access Journals (Sweden)

    Marta Pérez-Torralba

    2013-10-01

    Full Text Available Two novel tetrafluorinated 1,5-benzodiazepinones were synthesized and their X-ray structures determined. 6,7,8,9-Tetrafluoro-4-methyl-1,3-dihydro-2H-1,5-benzodiazepin-2-one crystallizes in the monoclinic P21/c space group and 6,7,8,9-tetrafluoro-1,4-dimethyl-1,3-dihydro-2H-1,5-benzodiazepin-2-one in the triclinic P−1 space group. Density functional theory studies at the B3LYP/6-311++G(d,p level were carried out on these compounds and on four non-fluorinated derivatives, allowing to calculate geometries, tautomeric energies and ring-inversion barriers, that were compared with the experimental results obtained by static and dynamic NMR in solution and in solid state.

  9. Primary and secondary interactions between CK2alpha and CK2beta lead to ring-like structures in the crystals of the CK2 holoenzyme

    DEFF Research Database (Denmark)

    Niefind, Karsten; Issinger, Olaf-Georg

    2005-01-01

    Protein kinase CK2 predominantly exists as a heterotetrameric holoenyzme consisting of two catalytic subunits (CK2alpha) and two non-catalytic subunits (CK2beta). Early investigations which we review here had revealed the presence of two types of contacts between CK2alpha and CK2beta: a primary...... interaction responsible for the stability of the CK2 holoenzyme and stimulatory for the catalytic activity, and a secondary interaction which is inhibitory and in which the acidic loop of CK2beta associates with the basic stretch and the (p+1)-loop of CK2alpha. At the end of the last decade both types...... a distinct aggregation propensity of CK2. We demonstrate here that in the CK2 holoenzyme crystals contacts between different CK2 tetramers exists which provide structural details of the secondary CK2alpha/CK2beta interactions. These mainly ionic interactions lead to trimeric rings of CK2 holoenzymes...

  10. Evaluation of retinoids for induction of the redundant gene ABCD2 as an alternative treatment option in X-linked adrenoleukodystrophy.

    Directory of Open Access Journals (Sweden)

    Franziska D Weber

    Full Text Available X-linked adrenoleukodystrophy (X-ALD, the most common peroxisomal disorder, is a clinically heterogeneous disease that can manifest as devastating inflammatory cerebral demyelination (CALD leading to death of affected males. Currently, the only curative treatment is allogeneic hematopoietic stem cell transplantation (HSCT. However, HSCT is only effective when performed at an early stage because the inflammation may progress for eighteen months after HSCT. Thus, alternative treatment options able to immediately halt the progression are urgently needed. X-ALD is caused by mutations in the ABCD1 gene, encoding the peroxisomal membrane protein ABCD1, resulting in impaired very long-chain fatty acid metabolism. The related ABCD2 protein is able to functionally compensate for ABCD1-deficiency both in vitro and in vivo. Recently, we demonstrated that of the cell types derived from CD34+ stem cells, predominantly monocytes but not lymphocytes are metabolically impaired in X-ALD. As ABCD2 is virtually not expressed in these cells, we hypothesize that a pharmacological up-regulation of ABCD2 should compensate metabolically and halt the inflammation in CALD. Retinoids are anti-inflammatory compounds known to act on ABCD2. Here, we investigated the capacity of selected retinoids for ABCD2 induction in human monocytes/macrophages. In THP-1 cells, 13-cis-retinoic acid reached the highest, fivefold, increase in ABCD2 expression. To test the efficacy of retinoids in vivo, we analyzed ABCD2 mRNA levels in blood cells isolated from acne patients receiving 13-cis-retinoic acid therapy. In treated acne patients, ABCD2 mRNA levels were comparable to pre-treatment levels in monocytes and lymphocytes. Nevertheless, when primary monocytes were in vitro differentiated into macrophages and treated with 13-cis-retinoic acid, we observed a fourfold induction of ABCD2. However, the level of ABCD2 induction obtained by retinoids alone is probably not of therapeutic relevance

  11. Evaluation of retinoids for induction of the redundant gene ABCD2 as an alternative treatment option in X-linked adrenoleukodystrophy.

    Science.gov (United States)

    Weber, Franziska D; Weinhofer, Isabelle; Einwich, Angelika; Forss-Petter, Sonja; Muneer, Zahid; Maier, Harald; Weber, Willi H A; Berger, Johannes

    2014-01-01

    X-linked adrenoleukodystrophy (X-ALD), the most common peroxisomal disorder, is a clinically heterogeneous disease that can manifest as devastating inflammatory cerebral demyelination (CALD) leading to death of affected males. Currently, the only curative treatment is allogeneic hematopoietic stem cell transplantation (HSCT). However, HSCT is only effective when performed at an early stage because the inflammation may progress for eighteen months after HSCT. Thus, alternative treatment options able to immediately halt the progression are urgently needed. X-ALD is caused by mutations in the ABCD1 gene, encoding the peroxisomal membrane protein ABCD1, resulting in impaired very long-chain fatty acid metabolism. The related ABCD2 protein is able to functionally compensate for ABCD1-deficiency both in vitro and in vivo. Recently, we demonstrated that of the cell types derived from CD34+ stem cells, predominantly monocytes but not lymphocytes are metabolically impaired in X-ALD. As ABCD2 is virtually not expressed in these cells, we hypothesize that a pharmacological up-regulation of ABCD2 should compensate metabolically and halt the inflammation in CALD. Retinoids are anti-inflammatory compounds known to act on ABCD2. Here, we investigated the capacity of selected retinoids for ABCD2 induction in human monocytes/macrophages. In THP-1 cells, 13-cis-retinoic acid reached the highest, fivefold, increase in ABCD2 expression. To test the efficacy of retinoids in vivo, we analyzed ABCD2 mRNA levels in blood cells isolated from acne patients receiving 13-cis-retinoic acid therapy. In treated acne patients, ABCD2 mRNA levels were comparable to pre-treatment levels in monocytes and lymphocytes. Nevertheless, when primary monocytes were in vitro differentiated into macrophages and treated with 13-cis-retinoic acid, we observed a fourfold induction of ABCD2. However, the level of ABCD2 induction obtained by retinoids alone is probably not of therapeutic relevance for X-ALD. In

  12. Saturn's Spectacular Ring System

    Science.gov (United States)

    Lissauer, Jack J.; DeVincenzi, Donald (Technical Monitor)

    2001-01-01

    Saturn's beautiful rings have fascinated astronomers since they were first observed by Galileo in 1610. The main rings consist of solid particles mostly in the 1 cm - 10 m range, composed primarily of water ice. The ring disk is exceptionally thin - the typical local thickness of the bright rings is tens of meters, whereas the diameter of the main rings is 250,000 km! The main rings exhibit substantial radial variations "ringlets", many of which are actively maintained via gravitational perturbations from Saturn's moons. Exterior to the main rings lie tenuous dust rings, which have little mass but occupy a very large volume of space. This seminar will emphasize the physics of ring-moon interactions, recent advances in our understanding of various aspects of the rings obtained from observations taken during 1995 when the rings appeared edge-on to the Earth and then to the Sun, and observations in subsequent years from HST.

  13. Investigation of 2D photonic crystal structure based channel drop filter using quad shaped photonic crystal ring resonator for CWDM system

    Energy Technology Data Exchange (ETDEWEB)

    Chhipa, Mayur Kumar, E-mail: mayurchhipa1@gmail.com; Dusad, Lalit Kumar [Government Engineering College Ajmer, Rajasthan (India); Rajasthan Technical University, Kota, Rajasthan (India)

    2016-05-06

    In this paper, the design & performance of two dimensional (2-D) photonic crystal structure based channel drop filter is investigated using quad shaped photonic crystal ring resonator. In this paper, Photonic Crystal (PhC) based on square lattice periodic arrays of Gallium Indium Phosphide (GaInP) rods in air structure have been investigated using Finite Difference Time Domain (FDTD) method and photonic band gap is being calculated using Plane Wave Expansion (PWE) method. The PhC designs have been optimized for telecommunication wavelength λ= 1571 nm by varying the rods lattice constant. The number of rods in Z and X directions is 21 and 20, with lattice constant 0.540 nm it illustrates that the arrangement of Gallium Indium Phosphide (GaInP) rods in the structure which gives the overall size of the device around 11.4 µm × 10.8 µm. The designed filter gives good dropping efficiency using 3.298, refractive index. The designed structure is useful for CWDM systems. This device may serve as a key component in photonic integrated circuits. The device is ultra compact with the overall size around 123 µm{sup 2}.

  14. Influence of Pyrazine Ring Doping on the 15N and 11B NMR and Electronic Structure Parameters in Zigzag Boron Nitride Nanotube: A DFT Study

    Directory of Open Access Journals (Sweden)

    Sattar Arshadi

    2013-01-01

    Full Text Available Density functional theory (DFT calculations have been performed to investigate the properties of the electronic structures of pyrazine-doped boron nitride nanotubes (PD-BNNTs. The structural forms were firstly optimized and then nuclear magnetic resonance (NMR parameters have been calculated on the optimized structures. The chemical shielding isotropic ( and chemical shielding anisotropic ( parameters were calculated at the sites of 11B and 15N nuclei in structural forms of BNNT including the perfect (a model and PD-BNNTs (b, (c, and (d models. The results indicated that the changes are most significant for those nuclei placed in the nearest neighborhood of the pyrazine-doped ring. The changes of the electronic sites of the N atoms are also more significant than those of the B atoms. The difference of LUMO-HOMO gap for the perfect model was larger than the PD-BNNTs models. Also the atomic charge distribution of N and B atoms has been determined in nanotubes by natural bond orbital (NBO analysis. All calculations were performed by the B3LYP method and 6-311G** basis set using Gaussian 98 package of program.

  15. Burnside Rings of Fusion Systems

    DEFF Research Database (Denmark)

    Reeh, Sune Precht

    In this thesis we study the interactions between saturated fusion systems and group actions of the underlying p-groups. For a saturated fusion system F on a finite p-group S we construct the Burnside ring of F in terms of the finite S-sets whose actions respect the structure of the fusion system...... of the characteristic idempotent of F { the unique idempotent in the p-local double Burnside ring of S satisfying properties of Linckelmann and Webb. We describe this idempotent both in terms of fixed points and as a linear combination of transitive bisets. Additionally, using fixed points we determine the map...... of Burnside rings given by multiplication with the characteristic idempotent, and we show that this map is the transfer map previously constructed. Applying these results, we show that for every saturated fusion system the ring generated by all (non-idempotent) characteristic elements in the p-local double...

  16. A novel mutation in the ABCD1 gene of a Moroccan patient with X-linked adrenoleukodystrophy: case report.

    Science.gov (United States)

    Karkar, Adnane; Barakat, Abdelhamid; Bakhchane, Amina; Fettah, Houda; Slassi, Ilham; Dorboz, Imen; Boespflug-Tanguy, Odile; Nadifi, Sellama

    2015-11-25

    X-linked adrenoleukodystrophy (X-ALD; OMIM: 300100) is the most common peroxisomal disease caused by mutations in the ATP-binding cassette, sub-family D member 1 gene or ABCD1 (geneID: 215), the coding gene for the adrenoleukodystrophy protein (ALDP), which is an ATP-binding transport protein associated to an active transport of very long chain fatty acids (VLCFAs). Dysfunction of ALDP induces an accumulation of VLCFAs in all tissues leading to a neurodegenerative disorder that involves the nervous system white matter. In our case report, magnetic resonance imaging (MRI) as well as the high levels of VLCFAs prompted the diagnosis the X-ALD. Molecular analysis of ABCD1 gene have shown a pathogenic homozygous nonsense mutation (c.1677C > G; p.(Tyr559*)) in exon 7. Thus, we identified here a novel mutation in the ABCD1 gene in a Moroccan patient causing X-linked adrenoleukodystrophy.

  17. Matrix vaccination guidelines: 2015 ABCD recommendations for indoor/outdoor cats, rescue shelter cats and breeding catteries.

    Science.gov (United States)

    Hosie, Margaret J; Addie, Diane D; Boucraut-Baralon, Corine; Egberink, Herman; Frymus, Tadeusz; Gruffydd-Jones, Tim; Hartmann, Katrin; Horzinek, Marian C; Lloret, Albert; Lutz, Hans; Marsilio, Fulvio; Pennisi, Maria Grazia; Radford, Alan D; Thiry, Etienne; Truyen, Uwe; Möstl, Karin

    2015-07-01

    In 2013, the ABCD published 'Matrix vaccination guidelines: ABCD recommendations for indoor/outdoor cats, rescue shelter cats and breeding catteries' in a Special Issue of the Journal of Feline Medicine and Surgery (Volume 15, Issue 7, pages 540-544). The ABCD's vaccination recommendations were presented in tabulated form, taking into account that there is no universal vaccination protocol for all cats. To support the veterinarian's decision making, recommendations for four lifestyles were made: for cats with outdoors access, cats kept solely indoors, rescue shelter cats and cats in breeding catteries. This update article follows the same approach, offering current and, where relevant, expanded recommendations. © Published by SAGE on behalf of ISFM and AAFP 2015.

  18. Heptaphyrins: Expanded porphyrins with seven heterocyclic rings

    Indian Academy of Sciences (India)

    The 30 heptaphyrins exhibit rich structural diversity where some of the heterocyclic rings in the macrocycle undergo a 180° ring flipping. An overview of the synthetic methods employed for the synthesis of heptaphyrins, their spectroscopic properties, structural behaviour and aromatic properties are highlighted in this paper ...

  19. Optofluidic ring resonator dye lasers

    Science.gov (United States)

    Sun, Yuze; Suter, Jonathan D.; Fan, Xudong

    2010-02-01

    We overview the recent progress on optofluidic ring resonator (OFRR) dye lasers developed in our research group. The fluidics and laser cavity design can be divided into three categories: capillary optofluidic ring resonator (COFRR), integrated cylindrical optofluidic ring resonator (ICOFRR), and coupled optofluidic ring resonator (CpOFRR). The COFRR dye laser is based on a micro-sized glass capillary with a wall thickness of a few micrometers. The capillary circular cross-section forms the ring resonator and supports the whispering gallery modes (WGMs) that interact evanescently with the gain medium in the core. The laser cavity structure is versatile to adapt to the gain medium of any refractive index. Owing to the high Q-factor (>109), the lasing threshold of 25 nJ/mm2 is achieved. Besides directly pump the dye molecules, lasing through fluorescence resonance energy transfer (FRET) between the donor and acceptor dye molecules is also studied in COFRR laser. The energy transfer process can be further controlled by designed DNA scaffold labeled with donor/acceptor molecules. The ICOFRR dye laser is based on a cylindrical ring resonator fused onto the inner surface of a thick walled glass capillary. The structure has robust mechanical strength to sustain rapid gain medium circulation. The CpOFRR utilizes a cylindrical ring resonator fused on the inner surface of the COFRR capillary. Since the capillary wall is thin, the individual WGMs of the cylindrical ring resonator and the COFRR couples strongly and forms Vernier effect, which provides a way to generate a single mode dye laser.

  20. Validation of the ABCD score in identifying individuals at high early risk of stroke after a transient ischemic attack: a hospital-based case series study.

    Science.gov (United States)

    Tsivgoulis, Georgios; Spengos, Konstantinos; Manta, Panagiota; Karandreas, Nikolaos; Zambelis, Thomas; Zakopoulos, Nikolaos; Vassilopoulos, Demetrios

    2006-12-01

    A simple score derived in the Oxfordshire Community Stroke Project (ABCD score) was able to identify individuals at high early risk of stroke after a transient ischemic attack (TIA) both in a population-based and a hospital-referred clinic cohort. We aimed to further validate the former score in a cohort of hospitalized TIA patients. We retrospectively reviewed the emergency room and hospital records of consecutive patients hospitalized in our neurological department with a definite TIA according to the World Health Organization (WHO) criteria during a 5-year period. The 6-point ABCD score (age [ or =60 years=1]; blood pressure [systolic 140 mm Hg and/or diastolic >90 mm Hg=1]; clinical features [unilateral weakness=2, speech disturbance without weakness=1, other symptom=0]; duration of symptoms [ or =60 minutes=2]) was used to stratify the 30-day stroke risk. The 30-day risk of stroke in the present case series (n=226) was 9.7% (95% CI, 5.8% to 13.6%). The ABCD score was highly predictive of 30-day risk of stroke (ABCD=0 to 2: 0%, ABCD=3: 3.5% [95% CI, 0% to 8.2%], ABCD=4: 7.6% [95% CI, 1.2% to 14.0%], ABCD=5: 21.3% [95% CI, 10.4% to 33.0%], ABCD=6: 31.3% [95% CI, 8.6% to 54.0%]; log-rank test=23.09; df=6; P=0.0008; P for linear trend across the ABCD score levels ABCD score of 5 to 6 was independently (PABCD score in identifying hospitalized TIA patients with a high risk of early stroke and provide further evidence for its potential applicability in clinical practice.

  1. Diamagnetism in zigzag hexagonal graphene rings

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ning, E-mail: xuning79530@126.com [Department of Physics, Yancheng Institute of Technology, Yancheng 224051 (China); Chen, Qiao [Department of Physics, Hunan Institute of Engineering, Xiangtan 411104 (China); Tian, Hongyu [Department of Physics, Yancheng Institute of Technology, Yancheng 224051 (China); Wang, Baolin [Department of Physics, Nanjing Normal University, Nanjing 210023 (China); Ding, Jianwen [Department of Physics, Xiangtan University, Xiangtan 411105 (China)

    2016-03-06

    Highlights: • Hexagonal graphene rings possess unusually large diamagnetic moments. • The magnetic-field-driven carriers flow clockwise and anticlockwise along the inner and outer edge of rings. • The value of magnetic moment is almost proportional to the number of atoms of rings. - Abstract: The electronic structure and magnetic response of hexagonal graphene rings have been studied within the tight-binding formalism. The calculations show that hexagonal graphene rings possess unusually large diamagnetic moments in the presence of a perpendicular magnetic field. The magnetic-field-driven carriers flow clockwise and anticlockwise along the inner and outer edge of rings owing to quantum Hall effect. The value of magnetic moment is almost proportional to the number of atoms of rings, due to more conduction electrons participating in magnetic moment forming process. Additionally, we find the diamagnetic moment shows a relative weak dependence on the temperature.

  2. AbCD: arbitrary coverage design for sequencing-based genetic studies.

    Science.gov (United States)

    Kang, Jian; Huang, Kuan-Chieh; Xu, Zheng; Wang, Yunfei; Abecasis, Gonçalo R; Li, Yun

    2013-03-15

    Recent advances in sequencing technologies have revolutionized genetic studies. Although high-coverage sequencing can uncover most variants present in the sequenced sample, low-coverage sequencing is appealing for its cost effectiveness. Here, we present AbCD (arbitrary coverage design) to aid the design of sequencing-based studies. AbCD is a user-friendly interface providing pre-estimated effective sample sizes, specific to each minor allele frequency category, for designs with arbitrary coverage (0.5-30×) and sample size (20-10 000), and for four major ethnic groups (Europeans, Africans, Asians and African Americans). In addition, we also present two software tools: ShotGun and DesignPlanner, which were used to generate the estimates behind AbCD. ShotGun is a flexible short-read simulator for arbitrary user-specified read length and average depth, allowing cycle-specific sequencing error rates and realistic read depth distributions. DesignPlanner is a full pipeline that uses ShotGun to generate sequence data and performs initial SNP discovery, uses our previously presented linkage disequilibrium-aware method to call genotypes, and, finally, provides minor allele frequency-specific effective sample sizes. ShotGun plus DesignPlanner can accommodate effective sample size estimate for any combination of high-depth and low-depth data (for example, whole-genome low-depth plus exonic high-depth) or combination of sequence and genotype data [for example, whole-exome sequencing plus genotyping from existing Genomewide Association Study (GWAS)].

  3. Propagation of an Airy-Gaussian beam passing through the ABCD optical system with a rectangular aperture

    Science.gov (United States)

    Liu, Huilong; Lü, Yanfei; Xia, Jing; Pu, Xiaoyun; Zhang, Li

    2015-11-01

    By expanding the hard rectangular aperture function into a finite sum of complex Gaussian functions, we obtain the analytical formula for the propagation of an AiG beam passing through a paraxial ABCD optical system. According to the derived formulas, the propagation properties of an AiG beam through a paraxial ABCD optical system with a hard rectangular aperture are illustrated numerically. As a special case, the fractional Fourier transformation (FrFT) system is taken into consideration. The derived analytical formulas provide a convenient and effective way for studying the propagation and transformation of an AiG beam through an apertured general optical system.

  4. The ABCD's of 5'-adenosine monophosphate-activated protein kinase and adrenoleukodystrophy.

    Science.gov (United States)

    Weidling, Ian; Swerdlow, Russell H

    2016-07-01

    This Editorial highlights a study by Singh and coworkers in the current issue of Journal of Neurochemistry, in which the authors present additional evidence that AMPKα1 is reduced in X-linked adrenoleukodystrophy (X-ALD). They make a case for increasing AMPKα1 activity for therapeutic purposes in this disease, and indicate how this goal may be achieved. Read the highlighted article 'Metformin-induced mitochondrial function and ABCD2 up regulation in X-linked adrenoleukodystrophy involves AMP activated protein kinase' on page 86. © 2016 International Society for Neurochemistry.

  5. The rings of Uranus - Occultation profiles from three observatories

    Science.gov (United States)

    Elias, J. H.; Frogel, J. A.; French, R. G.; Matthews, K.; Meech, K. J.; Mink, D. J.; Nicholson, P. D.; Sicardy, B.; Liller, W.; Elliot, J. L.

    1983-01-01

    Occultation profiles for the nine confirmed Uranian rings obtained from Las Campanas, the European Southern Observatory, and Cerro Tololo on 15-16 August 1980 are compared. The alpha ring shows a 'double-dip' structure; the eta ring shows a broad and narrow component (similar to Saturn's F ring); and the epsilon ring shows six features that appear in the data from all three observatories. Diffraction fringes appear at the edges of several of the occultation profiles.

  6. Electronic structure and Landé g-factor of a quantum ring in the presence of spin-orbit coupling: Temperature and Zeeman effect

    Science.gov (United States)

    Zamani, A.; Setareh, F.; Azargoshasb, T.; Niknam, E.

    2017-10-01

    A wide variety of semiconductor nanostructures have been fabricated experimentally and both theoretical and experimental investigations of their features imply the great role they have in new generation technological devices. However, mathematical modeling provide a powerful means due to definitive goal of predicting the features and understanding of such structures behavior under different circumstances. Therefore, effective Hamiltonian for an electron in a quantum ring with axial symmetry in the presence of both Rashba and Dresselhaus spin-orbit interactions (SOI) is derived. Here we report our study of the electronic structure and electron g-factor in the presence of spin-orbit (SO) couplings under the influence of external magnetic field at finite temperature. This investigation shows that, when Rashba and Dresselhaus couplings are simultaneously present, the degeneracy is removed and energy levels split into two branches. Furthermore, with enhancing the applied magnetic field, separation of former degenerate levels increases and also avoided crossings (anti-crossing) in the energy spectra is detected. It is also discussed how the energy levels of the system can be adjusted with variation of temperature as well as the magnetic field and geometrical sizes.

  7. Synthesis and quantitative structure-activity relationship (QSAR) study of novel 4-acyloxypodophyllotoxin derivatives modified in the A and C rings as insecticidal agents.

    Science.gov (United States)

    He, Shuzhen; Shao, Yonghua; Fan, Lingling; Che, Zhiping; Xu, Hui; Zhi, Xiaoyan; Wang, Juanjuan; Yao, Xiaojun; Qu, Huan

    2013-01-23

    In continuation of our program aimed at the discovery and development of natural-product-based insecticidal agents, we have synthesized three series of novel 4-acyloxy compounds derived from podophyllotoxin modified in the A and C rings, which is isolated as the main secondary metabolite from the roots and rhizomes of Podophyllum hexandrum . Their insecticidal activity was preliminarily evaluated against the pre-third-instar larvae of Mythimna separata in vivo. Compound 9g displayed the best promising insecticidal activity. It revealed that cleavage of the 6,7-methylenedioxy group of podophyllotoxin will lead to a less active compound and that the C-4 position of podophyllotoxin was the important modification location. A quantitative structure-activity relationship (QSAR) model was developed by genetic algorithm combined with multiple linear regression (GA-MLR). For this model, the squared correlation coefficient (R(2)) is 0.914, the leave-one-out cross-validation correlation coefficient (Q(2)(LOO)) is 0.881, and the root-mean-square error (RMSE) is 0.024. Five descriptors, BEHm2, Mor14v, Wap, G1v, and RDF020e, are likely to influence the biological activity of these compounds. Among them, two important ones are BEHm2 and Mor14v. This study will pave the way for further design, structural modification, and development of podophyllotoxin derivatives as insecticidal agents.

  8. Voyager Photometry of Saturn's A Ring

    Science.gov (United States)

    Dones, Luke; Cuzzi, Jeffrey N.; Showalter, Mark R.

    1993-01-01

    Saturn's A Ring samples a wide range of dynamical environments, from the relatively unperturbed, optically thick inner region to the outer part of the ring, which contains numerous density waves. We analyze Voyager images of the A Ring to determine how the reflectivity of different radial regions varies with lighting and viewing geometry. We model our data with a classical radiative transfer code that includes the illumination of the rings by the Sun and Saturn. The particles in the inner and mid-A Ring have Bond albedos near 0.5 and are more backscattering than satellites of comparable albedo. The region outside the Encke Gap becomes progressively less backscattering with increasing radius. Particle properties change abruptly outside the Keeler Gap; particles here have an albedo near 0.6 and a Lambert-like phase function. In contrast with previous suggestions, the abundance of free, submicrometer "dust" is small throughout the entire A Ring; this conclusion holds even in the outermost A Ring, which is strongly perturbed by density waves. Models derived from low-phase data, assuming only macroscopic particles, correctly predict the highphase reflectivity of the outer A Ring and individual strong density waves in the mid-A Ring. However, the inner and mid-A Ring are typically darker at high phase by a factor of two than our models predict. This discrepancy may be due to the reduced multiple scattering from a layer in which the particles are more closely packed. We have also studied the quadrupole azimuthal brightness asymmetry of the A Ring. The asymmetry has a full amplitude of 35% in the mid-A Ring in low-phase Voyager 2 images. We present results on its behavior and possible implications for the structure of the rings. Finally, we compare our results with studies using other data sets to synthesize our current understanding of the nature of the A Ring.

  9. Semi-algebraic function rings and reflectors of partially ordered rings

    CERN Document Server

    Schwartz, Niels

    1999-01-01

    The book lays algebraic foundations for real geometry through a systematic investigation of partially ordered rings of semi-algebraic functions. Real spectra serve as primary geometric objects, the maps between them are determined by rings of functions associated with the spectra. The many different possible choices for these rings of functions are studied via reflections of partially ordered rings. Readers should feel comfortable using basic algebraic and categorical concepts. As motivational background some familiarity with real geometry will be helpful. The book aims at researchers and graduate students with an interest in real algebra and geometry, ordered algebraic structures, topology and rings of continuous functions.

  10. Genotype-phenotype correlation of contiguous gene deletions of SLC6A8, BCAP31 and ABCD1

    NARCIS (Netherlands)

    van de Kamp, J.M.; Errami, A.; Howidi, M.; Anselm, I.; Winter, S.; Phalin-Roque, J.; Osaka, H.; van Dooren, S.J.M.; Mancini, G.M.; Steinberg, S.J.; Salomons, G.

    2015-01-01

    The BCAP31 gene is located between SLC6A8, associated with X-linked creatine transporter deficiency, and ABCD1, associated with X-linked adrenoleukodystrophy. Recently, loss-of-function mutations in BCAP31 were reported in association with severe developmental delay, deafness and dystonia. We

  11. Are GOLD ABCD groups better associated with health status and costs than GOLD 1234 grades? A cross-sectional study

    NARCIS (Netherlands)

    M.R.S. Boland (Melinde); A. Tsiachristas (Apostolos); A.L. Kruis (Annemarije); N.H. Chavannes (Nicolas); M.P.M.H. Rutten-van Mölken (Maureen)

    2014-01-01

    markdownabstract__Abstract__ Aims: To investigate the association of the GOLD ABCD groups classification with costs and health-related quality of life (HR-QoL) and to compare this with the GOLD 1234 grades classification that was primarily based on lung function only. Methods: In a

  12. Structure-induced asymmetry between counterpropagating modes and the reciprocity principle in whistle-geometry ring lasers

    Science.gov (United States)

    Osiński, Marek; Kalagara, Hemashilpa; Lee, Hosuk; Smolyakov, Gennady A.

    2017-08-01

    Greatly enhanced high-speed modulation performance has been recently predicted in numerical calculations for a novel injection-locking scheme involving a distributed Bragg reflector master laser monolithically integrated with a unidirectional whistle-geometry semiconductor microring laser. Operation of these devices relies on the assumption of large difference between modal losses experienced by counterpropagating modes. In this work, we confirm the unidirectionality of the whistle-geometry configuration through rigorous three-dimensional finite-difference timedomain (FDTD) simulation by showing a strong asymmetry in photon lifetimes between the two counterpropagating modes. We also show that similar asymmetry occurs in three-port couplers, whose structure resembles the coupling section of whistle-geometry lasers. We explain why these results do not violate the Helmholtz reciprocity principle.

  13. Feedbacks between earlywood anatomy and non-structural carbohydrates affect spring phenology and wood production in ring-porous oaks

    Science.gov (United States)

    Pérez-de-Lis, Gonzalo; García-González, Ignacio; Rozas, Vicente; Olano, José Miguel

    2016-10-01

    Non-structural carbohydrates (NSC) play a central role in the construction and maintenance of a tree's vascular system, but feedbacks between the NSC status of trees and wood formation are not fully understood. We aimed to evaluate multiple dependencies among wood anatomy, winter NSC, and phenology for coexisting temperate (Quercus robur) and sub-Mediterranean (Q. pyrenaica) oaks along a water-availability gradient in the NW Iberian Peninsula. Sapwood NSC concentrations were quantified at three sites in December 2012 (N = 240). Leaf phenology and wood anatomy were surveyed in 2013. Structural equation modelling was used to analyse the interplay among hydraulic diameter (Dh), winter NSC, budburst date, and earlywood vessel production (EVP), while the effect of Dh and EVP on latewood width was assessed by using a mixed-effects model. NSC and wood production increased under drier conditions for both species. Q. robur showed a narrower Dh and lower soluble sugar (SS) concentration (3.88-5.08 % dry matter) than Q. pyrenaica (4.06-5.57 % dry matter), but Q. robur exhibited larger EVP and wider latewood (1403 µm) than Q. pyrenaica (667 µm). Stem diameter and Dh had a positive effect on SS concentrations, which were related to an earlier leaf flushing in both species. Sapwood sugar content appeared to limit EVP exclusively in Q. pyrenaica. In turn, Dh and EVP were found to be key predictors of latewood growth. Our results confirm that sapwood SS concentrations are involved in modulating growth resumption and xylem production in spring. Q. pyrenaica exhibited a tighter control of carbohydrate allocation to wood formation than Q. robur, which would play a role in protecting against environmental stress in the sub-Mediterranean area.

  14. The fractal theory of the Saturn Ring

    OpenAIRE

    Zelikin, Mikhail

    2015-01-01

    The true reason for partition of the Saturn ring as well as rings of other planets into great many of sub-rings is found. This reason is the theorem of Zelikin-Lokutsievskiy-Hildebrand about fractal structure of solutions to generic piece-wise smooth Hamiltonian systems. The instability of two-dimensional model of rings with continues surface density of particles distribution is proved both for Newtonian and for Boltzmann equations. We do not claim that we have solved the problem of stability...

  15. Diamagnetism in zigzag hexagonal graphene rings

    Science.gov (United States)

    Xu, Ning; Chen, Qiao; Tian, Hongyu; Wang, Baolin; Ding, Jianwen

    2016-03-01

    The electronic structure and magnetic response of hexagonal graphene rings have been studied within the tight-binding formalism. The calculations show that hexagonal graphene rings possess unusually large diamagnetic moments in the presence of a perpendicular magnetic field. The magnetic-field-driven carriers flow clockwise and anticlockwise along the inner and outer edge of rings owing to quantum Hall effect. The value of magnetic moment is almost proportional to the number of atoms of rings, due to more conduction electrons participating in magnetic moment forming process. Additionally, we find the diamagnetic moment shows a relative weak dependence on the temperature.

  16. p53-independent structure-activity relationships of 3-ring mesogenic compounds' activity as cytotoxic effects against human non-small cell lung cancer lines.

    Science.gov (United States)

    Fukushi, Saori; Yoshino, Hironori; Yoshizawa, Atsushi; Kashiwakura, Ikuo

    2016-07-25

    We recently demonstrated the cytotoxicity of liquid crystal precursors (hereafter referred to as "mesogenic compounds") in the human non-small cell lung cancer (NSCLC) cell line A549 which carry wild-type p53. p53 mutations are observed in 50 % of NSCLC and contribute to their resistance to chemotherapy. To develop more effective and cancer-specific agents, in this study, we investigated the structure-activity relationships of mesogenic compounds with cytotoxic effects against multiple NSCLC cells. The pharmacological effects of mesogenic compounds were examined in human NSCLC cells (A549, LU99, EBC-1, and H1299) and normal WI-38 human fibroblast. Analyses of the cell cycle, cell-death induction, and capsases expression were performed. The 3-ring compounds possessing terminal alkyl and hydroxyl groups (compounds C1-C5) showed cytotoxicity in NSCLC cells regardless of the p53 status. The compounds C1 and C3, which possess a pyrimidine at the center of the core, induced G2/M arrest, while the compounds without a pyrimidine (C2, C4, and C5) caused G1 arrest; all compounds produced caspase-mediated cell death. These events occurred in a p53-independent manner. Furthermore, it was suggested that compounds induced cell death through p53-independent DNA damage-signaling pathway. Compounds C2, C4, and C5 did not show strong cytotoxicity in WI-38 cells, whereas C1 and C3 did. However, the cytotoxicity of compound C1 against WI-38 cells was improved by modulating the terminal alkyl chain lengths of the compound. We showed the p53-indepdent structure-activity relationships of mesogenic compounds related to the cytotoxic effects. These structure-activity relationships will be helpful in the development of more effective and cancer-specific agents.

  17. Models of models: filtering and bias rings in depiction of knowledge structures and their implications for design.

    Science.gov (United States)

    Revell, Kirsten M A; Stanton, Neville A

    2012-01-01

    Mental models are poorly specified in three ways: in their defining criteria, their source and the bias to which they have been subjected. Literature from psychology, HCI and human factors sources was reviewed to determine the utility of 'mental models' as a design tool. The definitions and theories offered by key contributors to the notion of mental models were compared. Schematics, representing both the knowledge structures proposed in cognitive processing, as well as the layers of bias evident when forming or accessing mental models, were constructed. Fundamental similarities and differences in the use of this notion, as well as ambiguities in definition, were highlighted graphically. The need for specificity in the use of mental models was emphasised as essential for pragmatic application in design. The use of graphical comparison was proposed as a means of identifying the risk of bias and a means to categorise approaches to mental model research. Practitioner Summary: Mental models are considered significant in user centred design. To apply this notion pragmatically, its definition and methods of construction and access need to be sufficiently specified. This article offers a graphical method to compare existing research in mental models, highlighting similarities, differences and ambiguities.

  18. Structure–Activity Relationship of Oligomeric Flavan-3-ols: Importance of the Upper-Unit B-ring Hydroxyl Groups in the Dimeric Structure for Strong Activities

    Directory of Open Access Journals (Sweden)

    Yoshitomo Hamada

    2015-10-01

    Full Text Available Proanthocyanidins, which are composed of oligomeric flavan-3-ol units, are contained in various foodstuffs (e.g., fruits, vegetables, and drinks and are strongly biologically active compounds. We investigated which element of the proanthocyanidin structure is primarily responsible for this functionality. In this study, we elucidate the importance of the upper-unit of 4–8 condensed dimeric flavan-3-ols for antimicrobial activity against Saccharomyces cerevisiae (S. cerevisiae and cervical epithelioid carcinoma cell line HeLa S3 proliferation inhibitory activity. To clarify the important constituent unit of proanthocyanidin, we synthesized four dimeric compounds, (−-epigallocatechin-[4,8]-(+-catechin, (−-epigallocatechin-[4,8]-(−-epigallocatechin, (−-epigallocatechin-[4,8]-(−-epigallocatechin-3-O-gallate, and (+-catechin-[4,8]-(−-epigallocatechin and performed structure–activity relationship (SAR studies. In addition to antimicrobial activity against S. cerevisiae and proliferation inhibitory activity on HeLa S3 cells, the correlation of 2,2-diphenyl-l-picrylhydrazyl radical scavenging activity with the number of phenolic hydroxyl groups was low. On the basis of the results of our SAR studies, we concluded that B-ring hydroxyl groups of the upper-unit of the dimer are crucially important for strong and effective activity.

  19. Addressing Structural Flexibility at the A-Ring on Salvinorin A: Discovery of a Potent Kappa-Opioid Agonist with Enhanced Metabolic Stability.

    Science.gov (United States)

    Sherwood, Alexander M; Crowley, Rachel Saylor; Paton, Kelly F; Biggerstaff, Andrew; Neuenswander, Benjamin; Day, Victor W; Kivell, Bronwyn M; Prisinzano, Thomas E

    2017-05-11

    Previous structure-activity studies on the neoclerodane diterpenoid salvinorin A have demonstrated the importance of the acetoxy functionality on the A-ring in its activity as a κ-opioid receptor agonist. Few studies have focused on understanding the role of conformation in these interactions. Herein we describe the synthesis and evaluation of both flexible and conformationally restricted compounds derived from salvinorin A. One such compound, spirobutyrolactone 14, was synthesized in a single step from salvinorin B and had similar potency and selectivity to salvinorin A (EC50 = 0.6 ± 0.2 nM at κ; >10000 nM at μ and δ). Microsomal stability studies demonstrated that 14 was more metabolically resistant than salvinorin A. Evaluation of analgesic and anti-inflammatory properties revealed similar in vivo effects between 14 and salvinorin A. To our knowledge, this study represents the first example of bioisosteric replacement of an acetate group by a spirobutyrolactone to produce a metabolically resistant derivative.

  20. First high-power model of the annular-ring coupled structure for use in the Japan Proton Accelerator Research Complex linac

    Directory of Open Access Journals (Sweden)

    Hiroyuki Ao

    2012-01-01

    Full Text Available A prototype cavity for the annular-ring coupled structure (ACS for use in the Japan Proton Accelerator Research Complex (J-PARC linac has been developed to confirm the feasibility of achieving the required performance. This prototype cavity is a buncher module, which includes ten accelerating cells in total. The ACS cavity is formed by the silver brazing of ACS half-cell pieces stacked in a vacuum furnace. The accelerating cell of the ACS is surrounded by a coupling cell. We, therefore, tuned the frequencies of the accelerating and coupling cells by an ultraprecision lathe before brazing, taking into account the frequency shift due to brazing. The prototype buncher module was successfully conditioned up to 600 kW, which corresponds to an accelerating field that is higher than the designed field of 4.1  MV/m by 30%. We describe the frequency-tuning results for the prototype buncher module and its high-power conditioning.

  1. Groups, rings, modules

    CERN Document Server

    Auslander, Maurice

    2014-01-01

    This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions

  2. Avaliação do aprendizado dos pacientes sobre a regra do ABCD: um estudo randomizado no sul do Brasil Evaluation of patients’ learning about the ABCD rule: a randomized study in southern Brazil

    Directory of Open Access Journals (Sweden)

    Karen Reetz Müller

    2009-12-01

    Full Text Available FUNDAMENTOS: A regra do ABCD é utilizada para orientar médicos, profissionais da saúde e pacientes quanto ao reconhecimento das principais características de lesões cutâneas suspeitas de melanoma. Não há, no Brasil,estudos que validem a utilização da regra do ABCD pelos pacientes após orientações realizadas por dermatologistas. OBJETIVOS: Avaliar o aprendizado da regra do ABCD por pacientes atendidos em centro dermatológico de referência no sul do Brasil. MÉTODOS: Estudo randomizado com 80 pacientes ambulatoriais de ambos os sexos, com 12 anos ou mais. Foram avaliados: grau de escolaridade, renda mensal e acesso aos meios de comunicação. O grupo de intervenção recebeu orientações sobre o emprego da regra do ABCD, ao passo que o grupo-controle não recebeu. Ambos os grupos foram avaliados quanto às suas respostas em três momentos (basal, fora do consultório e no consultório, 15 dias após em painel de fotografias. O nível de significância utilizado foi o p Background: the ABCD rule is used to guide physicians, health care professionals and patients to recognize the main characteristics of suspicious skin lesions for melanoma. In Brazil there are no studies to validate the use of the ABCD rule by patients after instructions given by dermatologists. Objectives: to evaluate the learning of the ABCD rule by patients at a dermatology center of reference in the Southern region of Brazil. Methods: a randomized study, with 80 outpatients. The following were evaluated: sex, age, level of schooling, monthly income and access to means of communication. The intervention group received instructions regarding the use of the ABCD rule and the control group did not. Both groups were evaluated at three points in time (baseline; outside the office; and in the doctor's office, 15 days later regarding their answers about a panel of photographs. The level of significance used was p < 0.05 and a power of 0.80. Results: the group that

  3. Synthesis of Hyperbranched Poly(ε-caprolactone Containing Terminal Azobenzene Structure via Combined Ring-Opening Polymerization and “Click” Chemistry

    Directory of Open Access Journals (Sweden)

    Xiaoqiang Xue

    2015-07-01

    Full Text Available A novel well-defined linear poly(ε-caprolactone (P1 containing terminal azobenzene and ethyne groups was successfully synthesized through tin-catalyzed ring-opening polymerization of ε-caprolactone in the presence of N,N′-bis(2-hydroxyethyl-4-(3-ethynylphenylazoaniline (BHA in bulk. Subsequent reactions allowed the synthesis of the corresponding bromoester end-functionalized polymer (P2, which was converted into AB2 type polymer (P3 containing terminal azide groups with NaN3. Consequently, hyperbranched poly(ε-caprolactone (HPCL was prepared with AB2 macromonomer (P3 by “click” chemistry under the catalysis of CuSO4·5H2O/sodium ascorbate/H2O. The structure of the resultant HPCL was characterized by gel permeation chromatography (GPC, proton nuclear magnetic resonance (1H-NMR, ultraviolet-visible (UV-Vis spectroscopy and fourier transform infrared spectroscopy (FT-IR. Thermal and crystallization properties of P1 and HPCL were further studied by differential scanning calorimetry (DSC, wide-angle X-ray diffraction (WAXD and polarised optical microscopy (POM. These results indicated that the crystallinity of HPCL was slightly lower than that of P1 due to the hyperbranched structure of HPCL. Additionally, the photo-induced trans-cis isomerization behaviors of BHA, P1 and HPCL containing terminal azobenzene were investigated in chloroform solution, and the photoisomerization rate constant (kexp of small molecule (BHA was nearly three times faster than that of polymers P1 and HPCL, which was due to the sterically hindering effect of the polymer-chain configuration.

  4. Physics of quantum rings

    CERN Document Server

    Fomin, Vladimir M

    2013-01-01

    This book deals with a new class of materials, quantum rings. Innovative recent advances in experimental and theoretical physics of quantum rings are based on the most advanced state-of-the-art fabrication and characterization techniques as well as theoretical methods. The experimental efforts allow to obtain a new class of semiconductor quantum rings formed by capping self-organized quantum dots grown by molecular beam epitaxy. Novel optical and magnetic properties of quantum rings are associated with non-trivial topologies at the nanoscale. An adequate characterization of quantum rings is po

  5. [Variations of Picea crassifolia tree-ring cell structure and their implications to past climate in eastern margin of Qaidam Basin, Northwest China].

    Science.gov (United States)

    Li, Yan; Liang, Er-Yuan; Shao, Xue-mei

    2008-03-01

    Tree-ring samples of Picea crassifolia were collected from the upper tree-line in the eastern mountainous area of Qaidam Basin in Qinghai Province. The tree-ring width and the cell number and size of the tree-ring were measured, and the standard chronologies for the early-wood cell number, late-wood cell number, total cell number of tree-rings, maximum cell size, and minimum cell size were constructed. By using correlation analysis and the response functions between cell characteristic indices and 1970-2000 climate factors at Chaka meteorological station which was close to the sampling site, the relationships between P. crassifolia growth at cell scale and climate factors were discussed. The results showed that the early-wood cell number was positively correlated to the wintertime temperature from previous October to current March, while the late-wood cell number was positively correlated to the minimum temperature in previous November and December and to the mean temperature in current July and August. Both the early-wood and the late-wood cell numbers were negatively correlated to the precipitation in July, and the early-wood cell number was positively correlated to the precipitation in May. The chronology of maximum cell size of early-wood was positively related to the precipitation in February, while that of minimum cell size of late-wood was positivelyrelated to the precipitation in August. It was concluded that the cell number and cell size could not only reveal the information of temperature change, which was recorded by tree ring width as well, but also provide additional information of precipitation. Since different types of tree-ring indices contained different climate information, multiple aspects of climate change information could be extracted from different tree-ring indices of the same species at the same site, and the cell level tree ring characteristics had great potential to supply the information regarding past climate.

  6. An evolving view of Saturn's dynamic rings.

    Science.gov (United States)

    Cuzzi, J N; Burns, J A; Charnoz, S; Clark, R N; Colwell, J E; Dones, L; Esposito, L W; Filacchione, G; French, R G; Hedman, M M; Kempf, S; Marouf, E A; Murray, C D; Nicholson, P D; Porco, C C; Schmidt, J; Showalter, M R; Spilker, L J; Spitale, J N; Srama, R; Sremcević, M; Tiscareno, M S; Weiss, J

    2010-03-19

    We review our understanding of Saturn's rings after nearly 6 years of observations by the Cassini spacecraft. Saturn's rings are composed mostly of water ice but also contain an undetermined reddish contaminant. The rings exhibit a range of structure across many spatial scales; some of this involves the interplay of the fluid nature and the self-gravity of innumerable orbiting centimeter- to meter-sized particles, and the effects of several peripheral and embedded moonlets, but much remains unexplained. A few aspects of ring structure change on time scales as short as days. It remains unclear whether the vigorous evolutionary processes to which the rings are subject imply a much younger age than that of the solar system. Processes on view at Saturn have parallels in circumstellar disks.

  7. Galactic rings revisited - I. CVRHS classifications of 3962 ringed galaxies from the Galaxy Zoo 2 Database

    Science.gov (United States)

    Buta, Ronald J.

    2017-11-01

    Rings are important and characteristic features of disc-shaped galaxies. This paper is the first in a series that re-visits galactic rings with the goals of further understanding the nature of the features and for examining their role in the secular evolution of galaxy structure. The series begins with a new sample of 3962 galaxies drawn from the Galaxy Zoo 2 citizen science data base, selected because zoo volunteers recognized a ring-shaped pattern in the morphology as seen in Sloan Digital Sky Survey colour images. The galaxies are classified within the framework of the Comprehensive de Vaucouleurs revised Hubble-Sandage system. It is found that zoo volunteers cued on the same kinds of ring-like features that were recognized in the 1995 Catalogue of Southern Ringed Galaxies. This paper presents the full catalogue of morphological classifications, comparisons with other sources of classifications and some histograms designed mainly to highlight the content of the catalogue. The advantages of the sample are its large size and the generally good quality of the images; the main disadvantage is the low physical resolution that limits the detectability of linearly small rings such as nuclear rings. The catalogue includes mainly inner and outer disc rings and lenses. Cataclysmic (`encounter-driven') rings (such as ring and polar ring galaxies) are recognized in less than 1 per cent of the sample.

  8. Novel fused pyrrole heterocyclic ring systems as structure analogs of LE 300: Synthesis and pharmacological evaluation as serotonin 5-HT(2A), dopamine and histamine H(1) receptor ligands.

    Science.gov (United States)

    Rostom, Sherif A F

    2010-02-01

    LE 300 represents a structurally novel type of antagonists acting preferentially at the dopamine D(1)/D(5 )receptors and the serotonin 5-HT(2A )receptor. This compound consists of a ten-membered central azecine ring fused to an indole ring on one side and a benzene moiety on the other side. To estimate the importance of the indole and / or phenyl moieties in this highly active benz-indolo-azecine, both rings were removed and replaced with a 1H-pyrrole counterpart. Accordingly, some new analogs of LE 300 namely, pyrrolo[2,3-g]indolizine, pyrrolo[3,2-a]quinolizine rings and their corresponding dimethylpyrrolo[2,3-d]azonine, and dimethylpyrrolo[2,3-d]azecine were synthesized to be evaluated for their activity at the 5-HT(2A) and dopamine D(1), D(2L), D(4), D(5) receptors in relation to LE 300. In addition, their activity at the H(1)-histamine receptors was also determined. The results suggested that the rigid pyrrolo[2,3-g]indolizine 7 and pyrrolo[3,2-a]quinolizine 8 analogs lacked biological activity in the adopted three bioassays. However, their corresponding flexible pyrrolo[2,3-d]azonine 11 and pyrrolo[2,3-d]azecine 12 derivatives revealed weak partial agonistic activity and weak antagonistic potency at the serotonin 5-HT(2A )and histamine H(1 )receptors, respectively. Meanwhile, they showed no affinity to any of the four utilized dopamine receptors. Variation in ring size did not contribute to a significant influence on the three tested bioactivities. Removal of the hydrophobic moiety (phenyl ring) and replacement of the indole moiety with a 1H-pyrrole counterpart led to a dramatic alteration in the profile of activity of such azecine-type compounds.

  9. Saturn's largest ring.

    Science.gov (United States)

    Verbiscer, Anne J; Skrutskie, Michael F; Hamilton, Douglas P

    2009-10-22

    Most planetary rings in the Solar System lie within a few radii of their host body, because at these distances gravitational accelerations inhibit satellite formation. The best known exceptions are Jupiter's gossamer rings and Saturn's E ring, broad sheets of dust that extend outward until they fade from view at five to ten planetary radii. Source satellites continuously supply the dust, which is subsequently lost in collisions or by radial transport. Here we report that Saturn has an enormous ring associated with its outer moon Phoebe, extending from at least 128R(S) to 207R(S) (Saturn's radius R(S) is 60,330 km). The ring's vertical thickness of 40R(S) matches the range of vertical motion of Phoebe along its orbit. Dynamical considerations argue that these ring particles span the Saturnian system from the main rings to the edges of interplanetary space. The ring's normal optical depth of approximately 2 x 10(-8) is comparable to that of Jupiter's faintest gossamer ring, although its particle number density is several hundred times smaller. Repeated impacts on Phoebe, from both interplanetary and circumplanetary particle populations, probably keep the ring populated with material. Ring particles smaller than centimetres in size slowly migrate inward and many of them ultimately strike the dark leading face of Iapetus.

  10. Fluid entrainment by isolated vortex rings

    Science.gov (United States)

    Dabiri, John O.; Gharib, Morteza

    2004-07-01

    Of particular importance to the development of models for isolated vortex ring dynamics in a real fluid is knowledge of ambient fluid entrainment by the ring. This time-dependent process dictates changes in the volume of fluid that must share impulse delivered by the vortex ring generator. Therefore fluid entrainment is also of immediate significance to the unsteady forces that arise due to the presence of vortex rings in starting flows. Applications ranging from industrial and transportation, to animal locomotion and cardiac flows, are currently being investigated to understand the dynamical role of the observed vortex ring structures. Despite this growing interest, fully empirical measurements of fluid entrainment by isolated vortex rings have remained elusive. The primary difficulties arise in defining the unsteady boundary of the ring, as well as an inability to maintain the vortex ring in the test section sufficiently long to facilitate measurements. We present a new technique for entrainment measurement that utilizes a coaxial counter-flow to retard translation of vortex rings generated from a piston cylinder apparatus, so that their growth due to fluid entrainment can be observed. Instantaneous streamlines of the flow are used to determine the unsteady vortex ring boundary and compute ambient fluid entrainment. Measurements indicate that the entrainment process does not promote self-similar vortex ring growth, but instead consists of a rapid convection-based entrainment phase during ring formation, followed by a slower diffusive mechanism that entrains ambient fluid into the isolated vortex ring. Entrained fluid typically constitutes 30% to 40% of the total volume of fluid carried with the vortex ring. Various counter-flow protocols were used to substantially manipulate the diffusive entrainment process, producing rings with entrained fluid fractions up to 65%. Measurements of vortex ring growth rate and vorticity distribution during diffusive entrainment

  11. Coherence and Polarization of Polarization Speckle Generated by Depolarizers and Their Changes through Complex ABCD Matrix

    DEFF Research Database (Denmark)

    Ma, Ning; Hanson, Steen Grüner; Lee, Tim K.

    2015-01-01

    Recent research work on speckle patterns indicates a variation of the polarization state during propagation and its nonuniformly spatial distribution. The preliminary step for the investigation of this polarization speckle is the generation of the corresponding field. In this paper, a kind...... of special depolarizer: the random roughness birefringent screen (RRBS) is introduced to meet this requirement. The statistical properties of the field generated by the depolarizer is investigated and illustrated in terms of the 2x2 beam coherence and polarization matrix (BCPM) with the corresponding degree...... of coherence (DoC). and degree of polarization (DoP) P. The changes of the coherence and polarization when the speckle field propagates through any optical system are analysed within the framework of the complex ABCD-matrix theory....

  12. Promoting competence in undergraduate medical students through the humanities: The ABCDE paradigm

    Directory of Open Access Journals (Sweden)

    Upreet Dhaliwal

    2015-06-01

    Full Text Available Stakeholders, including patients and employers, find that skills pertaining to professionalism, humanism, diversity, communication, and ethics are as important for patient care as the doctor’s ability to diagnose and treat illness. Practitioners should be able to demonstrate these skills in real time, yet they are not explicitly taught in the medical course – students are expected to learn them through observation of role models. Some students may never witness such role modeling. Research suggests that the creative instincts of medical students could be utilized through exposure to the humanities to explicitly develop these skills. Medical educators worldwide are examining newer ways to actively train and assess learners in professionalism and related competencies. Using Rudyard Kipling’s “Five Ws and One H” guide to writing a scientific paper, we propose the ABCDE paradigm and demonstrate why it is most appropriate to use the medical humanities to teach professionalism and humanism.

  13. Coherence and polarization of polarization speckle generated by depolarizers and their changes through complex ABCD matrix

    Science.gov (United States)

    Ma, Ning; Hanson, Steen G.; Lee, Tim K.; Takeda, Mitsuo; Wang, Wei

    2015-08-01

    Recent research work on speckle patterns indicates a variation of the polarization state during propagation and its nonuniformly spatial distribution. The preliminary step for the investigation of this polarization speckle is the generation of the corresponding field. In this paper, a kind of special depolarizer: the random roughness birefringent screen (RRBS) is introduced to meet this requirement. The statistical properties of the field generated by the depolarizer is investigated and illustrated in terms of the 2x2 beam coherence and polarization matrix (BCPM) with the corresponding degree of coherence (DoC) η and degree of polarization (DoP) P . The changes of the coherence and polarization when the speckle field propagates through any optical system are analysed within the framework of the complex ABCD-matrix theory.

  14. Double-bosonization and Majid's conjecture, (I): Rank-inductions of ABCD

    Science.gov (United States)

    Hu, Hongmei; Hu, Naihong

    2015-11-01

    Majid developed in [S. Majid, Math. Proc. Cambridge Philos. Soc. 125, 151-192 (1999)] the double-bosonization theory to construct Uq(𝔤) and expected to generate inductively not just a line but a tree of quantum groups starting from a node. In this paper, the authors confirm Majid's first expectation (see p. 178 [S. Majid, Math. Proc. Cambridge Philos. Soc. 125, 151-192 (1999)]) through giving and verifying the full details of the inductive constructions of Uq(𝔤) for the classical types, i.e., the ABCD series. Some examples in low ranks are given to elucidate that any quantum group of classical type can be constructed from the node corresponding to Uq(𝔰𝔩2).

  15. Double-bosonization and Majid’s conjecture, (I): Rank-inductions of ABCD

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Hongmei, E-mail: hmhu0124@126.com [School of Mathematical Sciences, University of Science and Technology of China, Jin Zhai Road 96, Hefei 230026 (China); Department of Mathematics, Shanghai Key Laboratory of Pure Mathematics and Mathematical Practice, East China Normal University, Minhang Campus, Dong Chuan Road 500, Shanghai 200241 (China); Hu, Naihong, E-mail: nhhu@math.ecnu.edu.cn [Department of Mathematics, Shanghai Key Laboratory of Pure Mathematics and Mathematical Practice, East China Normal University, Minhang Campus, Dong Chuan Road 500, Shanghai 200241 (China)

    2015-11-15

    Majid developed in [S. Majid, Math. Proc. Cambridge Philos. Soc. 125, 151–192 (1999)] the double-bosonization theory to construct U{sub q}(g) and expected to generate inductively not just a line but a tree of quantum groups starting from a node. In this paper, the authors confirm Majid’s first expectation (see p. 178 [S. Majid, Math. Proc. Cambridge Philos. Soc. 125, 151–192 (1999)]) through giving and verifying the full details of the inductive constructions of U{sub q}(g) for the classical types, i.e., the ABCD series. Some examples in low ranks are given to elucidate that any quantum group of classical type can be constructed from the node corresponding to U{sub q}(sl{sub 2})

  16. Propagation of symmetric tunable dual airy beam through ABCD optical system

    Science.gov (United States)

    Wen, Wei; Chu, Xiuxiang

    2014-12-01

    A simple mathematical model is proposed to describe symmetric tunable dual Airy beam (STDAB) [Opt. Lett. 39 (2014) 2370; Opt. Lett. 38 (2013) 1286; Opt. Lett. 37 (2012) 3402]. This beam is composed of two conventional Airy beams with a tunable parameter which have several distinguishing features. For example, the intensity distribution of the beam can be Gaussian, elliptical Gaussian, rectangular Gaussian or dumbbell shaped with difference tunable parameters. Based on the Collins integral formula, an analytical expression of the STDAB passing through a paraxial ABCD optical system is derived. For special cases, the propagation properties of the beams in free space and in chiral medium, passing a thin lens and passing a fractional Fourier transformation system are studied.

  17. Propagation of a partially coherent Lorentz-Gauss beam through a paraxial ABCD optical system.

    Science.gov (United States)

    Zhou, Guoquan

    2010-03-01

    Based on the generalized Huygens-Fresnel integral and the Hermite-Gaussian expansion of a Lorentz distribution, analytical expressions for the mutual coherence function, the effective beam size, and the spatial complex degree of coherence of a partially coherent Lorentz-Gauss beam through a paraxial and real ABCD optical system are derived, respectively. As a numerical example, the focusing of a partially coherent Lorentz-Gauss beam is considered. The normalized intensity distribution, the effective beam size, and the spatial complex degree of coherence for the focused partially coherent Lorentz-Gauss beam are numerically demonstrated in the focal plane. The influence of the spatial coherence length on the normalized intensity distribution, the effective beam size, and the spatial complex degree of coherence is mainly discussed.

  18. Symmetrical collision of multiple vortex rings

    Science.gov (United States)

    Hernández, R. H.; Reyes, T.

    2017-10-01

    In this work, we investigate the motion, interaction, and simultaneous collision between many initially stable vortex rings arranged symmetrically in two initial configurations, three and six rings making an angle of 60 and 120° between their straight path lines, respectively. We report results for laminar vortex rings in air obtained through numerical simulations of the ring velocity, pressure, and vorticity fields, both in free flight and during the entire collision. Each collision was studied for small Reynolds numbers R e formed by laterally expanding dipolar arms with top and bottom secondary vortex rings. The case of six colliding rings produces, as secondary structures, two big rings moving in opposite directions, a process that reminds us of the head-on collision of two rings [T. T. Lim and T. B. Nickels, "Instability and reconnection in the head-on collision of two vortex rings," Nature 357, 225-227 (1992)] under a hypothetical time reversal transformation. Both collisions display a characteristic kinetic energy evolution where mean collision stages can be identified within the range of Reynolds numbers investigated here.

  19. X-linked adrenoleukodystrophy: molecular and functional analysis of the ABCD1 gene in Argentinean patients.

    Directory of Open Access Journals (Sweden)

    Cyntia Anabel Amorosi

    Full Text Available X-linked adrenoleukodystrophy (X-ALD is an inherited metabolic disease associated with mutations in the ABCD1 gene that encodes an ATP-binding cassette transporter protein, ALDP. The disease is characterized by increased concentrations of very long-chain fatty acids (VLCFAs in plasma and in adrenal, testicular and nervous tissues, due to a defect in peroxisomal VLCFA β-oxidation. In the present study, we analyzed 10 male patients and 17 female carriers from 10 unrelated pedigrees with X-ALD from Argentina. By sequencing the ABCD1 we detected 9 different mutations, 8 of which were novel. These new mutations were verified by a combination of methods that included both functional (western blot and peroxisomal VLCFA β-oxidation and bioinformatics analysis. The spectrum of novel mutations consists of 3 frameshift (p.Ser284fs*16, p.Glu380Argfs*21 and p.Thr254Argfs*82; a deletion (p.Ser572_Asp575del; a splicing mutation (c.1081+5G>C and 3 missense mutations (p.Ala341Asp, p.His420Pro and p.Tyr547Cys. In one patient 2 changes were found: a known missense (p.His669Arg and an unpublished amino acid substitution (p.Ala19Ser. In vitro studies suggest that p.Ala19Ser is a polymorphism. Moreover, we identified two novel intronic polymorphisms and two amino acid polymorphisms. In conclusion, this study extends the spectrum of mutation in X-ALD and facilitates the identification of heterozygous females.

  20. X-Linked Adrenoleukodystrophy: Molecular and Functional Analysis of the ABCD1 Gene in Argentinean Patients

    Science.gov (United States)

    Amorosi, Cyntia Anabel; Myskóva, Helena; Monti, Mariela Roxana; Argaraña, Carlos Enrique; Morita, Masashi; Kemp, Stephan; de Kremer, Raquel Dodelson; Dvoráková, Lenka; de Ramírez, Ana María Oller

    2012-01-01

    X-linked adrenoleukodystrophy (X-ALD) is an inherited metabolic disease associated with mutations in the ABCD1 gene that encodes an ATP-binding cassette transporter protein, ALDP. The disease is characterized by increased concentrations of very long-chain fatty acids (VLCFAs) in plasma and in adrenal, testicular and nervous tissues, due to a defect in peroxisomal VLCFA β-oxidation. In the present study, we analyzed 10 male patients and 17 female carriers from 10 unrelated pedigrees with X-ALD from Argentina. By sequencing the ABCD1 we detected 9 different mutations, 8 of which were novel. These new mutations were verified by a combination of methods that included both functional (western blot and peroxisomal VLCFA β-oxidation) and bioinformatics analysis. The spectrum of novel mutations consists of 3 frameshift (p.Ser284fs*16, p.Glu380Argfs*21 and p.Thr254Argfs*82); a deletion (p.Ser572_Asp575del); a splicing mutation (c.1081+5G>C) and 3 missense mutations (p.Ala341Asp, p.His420Pro and p.Tyr547Cys). In one patient 2 changes were found: a known missense (p.His669Arg) and an unpublished amino acid substitution (p.Ala19Ser). In vitro studies suggest that p.Ala19Ser is a polymorphism. Moreover, we identified two novel intronic polymorphisms and two amino acid polymorphisms. In conclusion, this study extends the spectrum of mutation in X-ALD and facilitates the identification of heterozygous females. PMID:23300730

  1. [Development of an assessment of basic care for the demented (ABCD)].

    Science.gov (United States)

    Asada, T; Yoshioka, M; Morikawa, S; Koyama, H; Kitajima, E; Kawasaki, K; Kinoshita, T; Asa, A

    1994-02-01

    A rating scale measuring care status related to assistance with basic ADL for demented patients was developed. This instrument, named the ABCD, is designed to be completed by family and professional caregivers, and consists of two subscales assessing the level of difficulty of help with the ADL (difficulty scale) and the reasons why assistance is needed (reason category). In the difficulty scale, each of 6 items is rated with 4 possible responses corresponding to the degree of physical assistance from the caregiver and of the patient's cooperation with the assistance. In the reason category, for 5 activities excluding voiding, the reason is assessed with the following three possible responses: A; physical disability, B; disability in motivation and/or so-called apraxia, C; a combination of A and B. The ABCD was administered to 124 outpatients and 203 inpatients with dementia based on the DSM III-R criteria in order to test its reliability and validity. The data from the out- and inpatient samples were analyzed separately. The reliability study of the two subscales based on calculation of perfect agreement rates and kappa values indicated high test-retest and inter-rater reliability for both samples. The Cronbach alpha values of the difficulty scale were also high. As to the validity of the difficulty scale, there was a significantly high correlation between the score obtained with this scale and the results of two established assessment instruments. For the outpatients, logistic regression analysis revealed that the score obtained with this scale was the only predictor of institutionalization and mortality within 1 year after the baseline examination.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Saturn Ring Data Analysis and Thermal Modeling

    Science.gov (United States)

    Dobson, Coleman

    2011-01-01

    CIRS, VIMS, UVIS, and ISS (Cassini's Composite Infrared Specrtometer, Visual and Infrared Mapping Spectrometer, Ultra Violet Imaging Spectrometer and Imaging Science Subsystem, respectively), have each operated in a multidimensional observation space and have acquired scans of the lit and unlit rings at multiple phase angles. To better understand physical and dynamical ring particle parametric dependence, we co-registered profiles from these three instruments, taken at a wide range of wavelengths, from ultraviolet through the thermal infrared, to associate changes in ring particle temperature with changes in observed brightness, specifically with albedos inferred by ISS, UVIS and VIMS. We work in a parameter space where the solar elevation range is constrained to 12 deg - 14 deg and the chosen radial region is the B3 region of the B ring; this region is the most optically thick region in Saturn's rings. From this compilation of multiple wavelength data, we construct and fit phase curves and color ratios using independent dynamical thermal models for ring structure and overplot Saturn, Saturn ring, and Solar spectra. Analysis of phase curve construction and color ratios reveals thermal emission to fall within the extrema of the ISS bandwidth and a geometrical dependence of reddening on phase angle, respectively. Analysis of spectra reveals Cassini CIRS Saturn spectra dominate Cassini CIRS B3 Ring Spectra from 19 to 1000 microns, while Earth-based B Ring Spectrum dominates Earth-based Saturn Spectrum from 0.4 to 4 microns. From our fits we test out dynamical thermal models; from the phase curves we derive ring albedos and non-lambertian properties of the ring particle surfaces; and from the color ratios we examine multiple scattering within the regolith of ring particles.

  3. Affect, Behavior, Cognition, and Desire in the Big Five: An Analysis of Item Content and Structure.

    Science.gov (United States)

    Wilt, Joshua; Revelle, William

    2015-01-01

    Personality psychology is concerned with affect (A), behavior (B), cognition (C) and desire (D), and personality traits have been defined conceptually as abstractions used to either explain or summarize coherent ABC (and sometimes D) patterns over time and space. However, this conceptual definition of traits has not been reflected in their operationalization, possibly resulting in theoretical and practical limitations to current trait inventories. Thus, the goal of this project was to determine the affective, behavioral, cognitive and desire (ABCD) components of Big-Five personality traits. The first study assessed the ABCD content of items measuring Big-Five traits in order to determine the ABCD composition of traits and identify items measuring relatively high amounts of only one ABCD content. The second study examined the correlational structure of scales constructed from items assessing ABCD content via a large, web-based study. An assessment of Big-Five traits that delineates ABCD components of each trait is presented, and the discussion focuses on how this assessment builds upon current approaches of assessing personality.

  4. Combination of 3D skin surface texture features and 2D ABCD features for improved melanoma diagnosis.

    Science.gov (United States)

    Ding, Yi; John, Nigel W; Smith, Lyndon; Sun, Jiuai; Smith, Melvyn

    2015-10-01

    Two-dimensional asymmetry, border irregularity, colour variegation and diameter (ABCD) features are important indicators currently used for computer-assisted diagnosis of malignant melanoma (MM); however, they often prove to be insufficient to make a convincing diagnosis. Previous work has demonstrated that 3D skin surface normal features in the form of tilt and slant pattern disruptions are promising new features independent from the existing 2D ABCD features. This work investigates that whether improved lesion classification can be achieved by combining the 3D features with the 2D ABCD features. Experiments using a nonlinear support vector machine classifier show that many combinations of the 2D ABCD features and the 3D features can give substantially better classification accuracy than using (1) single features and (2) many combinations of the 2D ABCD features. The best 2D and 3D feature combination includes the overall 3D skin surface disruption, the asymmetry and all the three colour channel features. It gives an overall 87.8 % successful classification, which is better than the best single feature with 78.0 % and the best 2D feature combination with 83.1 %. These demonstrate that (1) the 3D features have additive values to improve the existing lesion classification and (2) combining the 3D feature with all the 2D features does not lead to the best lesion classification. The two ABCD features not selected by the best 2D and 3D combination, namely (1) the border feature and (2) the diameter feature, were also studied in separate experiments. It found that inclusion of either feature in the 2D and 3D combination can successfully classify 3 out of 4 lesion groups. The only one group not accurately classified by either feature can be classified satisfactorily by the other. In both cases, they have shown better classification performances than those without the 3D feature in the combinations. This further demonstrates that (1) the 3D feature can be used to

  5. Loss of AMP-Activated Protein Kinase Induces Mitochondrial Dysfunction and Proinflammatory Response in Unstimulated Abcd1-Knockout Mice Mixed Glial Cells

    Directory of Open Access Journals (Sweden)

    Jaspreet Singh

    2015-01-01

    Full Text Available X-linked adrenoleukodystrophy (X-ALD is caused by mutations and/or deletions in the ABCD1 gene. Similar mutations/deletions can give rise to variable phenotypes ranging from mild adrenomyeloneuropathy (AMN to inflammatory fatal cerebral adrenoleukodystrophy (ALD via unknown mechanisms. We recently reported the loss of the anti-inflammatory protein adenosine monophosphate activated protein kinase (AMPKα1 exclusively in ALD patient-derived cells. X-ALD mouse model (Abcd1-knockout (KO mice mimics the human AMN phenotype and does not develop the cerebral inflammation characteristic of human ALD. In this study we document that AMPKα1 levels in vivo (in brain cortex and spinal cord and in vitro in Abcd1-KO mixed glial cells are similar to that of wild type mice. Deletion of AMPKα1 in the mixed glial cells of Abcd1-KO mice induced spontaneous mitochondrial dysfunction (lower oxygen consumption rate and ATP levels. Mitochondrial dysfunction in ALD patient-derived cells and in AMPKα1-deleted Abcd1-KO mice mixed glial cells was accompanied by lower levels of mitochondrial complex (1-V subunits. More importantly, AMPKα1 deletion induced proinflammatory inducible nitric oxide synthase levels in the unstimulated Abcd1-KO mice mixed glial cells. Taken together, this study provides novel direct evidence for a causal role for AMPK loss in the development of mitochondrial dysfunction and proinflammatory response in X-ALD.

  6. A matrix ring description for cyclic convolutional codes

    NARCIS (Netherlands)

    Gluesing-Luerssen, Heide.; Tsang, Fai. -Lung.

    In this paper, we study convolutional codes with a specific cyclic structure. By definition, these codes are left ideals in a certain skew polynomial ring. Using that the skew polynomial ring is isomorphic to a matrix ring we can describe the algebraic parameters of the codes in a more accessible

  7. Token ring technology report

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. This report provides an overview of the IBM Token-Ring technology and products built by IBM and compatible vendors. It consists of two sections: 1. A summary of the design trade-offs for the IBM Token-Ring. 2. A summary of the products of the major token-ring compatible vendors broken down by adapters and components, wiring systems, testing, and new chip technology.

  8. Ordered Rings and Fields

    Directory of Open Access Journals (Sweden)

    Schwarzweller Christoph

    2017-03-01

    Full Text Available We introduce ordered rings and fields following Artin-Schreier’s approach using positive cones. We show that such orderings coincide with total order relations and give examples of ordered (and non ordered rings and fields. In particular we show that polynomial rings can be ordered in (at least two different ways [8, 5, 4, 9]. This is the continuation of the development of algebraic hierarchy in Mizar [2, 3].

  9. Radioactive gold ring dermatitis

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.A.; Aldrich, J.E. (Dalhousie Univ., Halifax, Nova Scotia (Canada))

    1990-08-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy.

  10. Research on propagation properties of controllable hollow flat-topped beams in turbulent atmosphere based on ABCD matrix

    Science.gov (United States)

    Liu, Huilong; Lü, Yanfei; Zhang, Jing; Xia, Jing; Pu, Xiaoyun; Dong, Yuan; Li, Shutao; Fu, Xihong; Zhang, Angfeng; Wang, Changjia; Tan, Yong; Zhang, Xihe

    2015-01-01

    This paper studies the propagation properties of controllable hollow flat-topped beams (CHFBs) in turbulent atmosphere based on ABCD matrix, sets up a propagation model and obtains an analytical expression for the propagation. With the help of numerical simulation, the propagation properties of CHFBs in different parameters are studied. Results indicate that in turbulent atmosphere, with the increase of propagation distance, the darkness of CHFBs gradually annihilate, and eventually evolve into Gaussian beams. Compared with the propagation properties in free space, the turbulent atmosphere enhances the diffraction effect of CHFBs and reduces the propagation distance for CHFBs to evolve into Gaussian beams. In strong turbulence atmospheric propagation, Airy disk phenomenon will disappear. The study on the propagation properties of CHFBs in turbulence atmosphere by using ABCD matrix is simple and convenient. This method can also be applied to study the propagation properties of other hollow laser beams in turbulent atmosphere.

  11. Metformin-induced mitochondrial function and ABCD2 up-regulation in X-linked adrenoleukodystrophy involves AMP-activated protein kinase.

    Science.gov (United States)

    Singh, Jaspreet; Olle, Brittany; Suhail, Hamid; Felicella, Michelle M; Giri, Shailendra

    2016-07-01

    X-linked adrenoleukodystrophy (X-ALD) is a progressive neurometabolic disease caused by mutations/deletions in the Abcd1 gene. Similar mutations/deletions in the Abcd1 gene often result in diagonally opposing phenotypes of mild adrenomyeloneuropathy and severe neuroinflammatory cerebral adrenoleukodystrophy (ALD), which suggests involvement of downstream modifier genes. We recently documented the first evidence of loss of AMP-activated protein kinase α1 (AMPKα1) in ALD patient-derived cells. Here, we report the novel loss of AMPKα1 in postmortem brain white matter of patients with ALD phenotype. Pharmacological activation of AMPK can rescue the mitochondrial dysfunction and inhibit the pro-inflammatory response. The FDA approved anti-diabetic drug Metformin, a well-known AMPK activator, induces mitochondrial biogenesis and is documented for its anti-inflammatory role. We observed a dose-dependent activation of AMPKα1 in metformin-treated X-ALD patient-derived fibroblasts. Metformin also induced mitochondrial oxidative phosphorylation and ATP levels in X-ALD patient-derived fibroblasts. Metformin treatment decreased very long chain fatty acid levels and pro-inflammatory cytokine gene expressions in X-ALD patient-derived cells. Abcd2 [adrenoleukodystrophy protein-related protein] levels were increased in metformin-treated X-ALD patient-derived fibroblasts and Abcd1-KO mice primary mixed glial cells. Abcd2 induction was AMPKα1-dependent since metformin failed to induce Abcd2 levels in AMPKα1-KO mice-derived primary mixed glial cells. In vivo metformin (100 mg/Kg) in drinking water for 60 days induced Abcd2 levels and mitochondrial oxidative phosphorylation protein levels in the brain and spinal cord of Abcd1-KO mice. Taken together, these results provide proof-of-principle for therapeutic potential of metformin as a useful strategy for correcting the metabolic and inflammatory derangements in X-ALD by targeting AMPK. There is no effective therapy for inherited

  12. The refined ABCD assessment and non-costly laboratory parameters are outcome predictors in acute exacerbation of COPD

    Directory of Open Access Journals (Sweden)

    Hend M. Esmaeel

    2017-10-01

    Conclusions: Elevated NLR can be used as a marker similar to ESR, in the determination of increased inflammation in acutely exacerbated COPD.A prognostic role was recognized for the ABCD GOLD categories. So when we faced by a patient with AECOPD, putting the clinical evaluation, including his gold category, side by side to the simple laboratory data will give good idea about the likely prognosis.

  13. Genotype-phenotype correlation of contiguous gene deletions of SLC6A8, BCAP31 and ABCD1.

    Science.gov (United States)

    van de Kamp, J M; Errami, A; Howidi, M; Anselm, I; Winter, S; Phalin-Roque, J; Osaka, H; van Dooren, S J M; Mancini, G M; Steinberg, S J; Salomons, G S

    2015-02-01

    The BCAP31 gene is located between SLC6A8, associated with X-linked creatine transporter deficiency, and ABCD1, associated with X-linked adrenoleukodystrophy. Recently, loss-of-function mutations in BCAP31 were reported in association with severe developmental delay, deafness and dystonia. We characterized the break points in eight patients with deletions of SLC6A8, BCAP31 and/or ABCD1 and studied the genotype-phenotype correlations. The phenotype in patients with contiguous gene deletions involving BCAP31 overlaps with the phenotype of isolated BCAP31 deficiency. Only deletions involving both BCAP31 and ABCD1 were associated with hepatic cholestasis and death before 1 year, which might be explained by a synergistic effect. Remarkably, a patient with an isolated deletion at the 3'-end of SLC6A8 had a similar severe phenotype as seen in BCAP31 deficiency but without deafness. This might be caused by the disturbance of a regulatory element between SLC6A8 and BCAP31. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. The A1C and ABCD of glycaemia management in type 2 diabetes: a physician's personalized approach.

    Science.gov (United States)

    Pozzilli, Paolo; Leslie, R David; Chan, Juliana; De Fronzo, Ralph; Monnier, Louis; Raz, Itamar; Del Prato, Stefano

    2010-05-01

    Recent intervention trials (Veterans Affairs Diabetes Trial, Action to Control Cardiovascular Risk in Diabetes, Action in Diabetes and Vascular Disease) have underscored problems surrounding the risk-benefit balance of most therapeutic strategies in type 2 diabetes given, especially the limited cardiovascular advantage of tight glycaemic control when set against the co-incident risk of severe hypoglycaemia and weight gain. Consequently, therapy should to tailored to the individual. While attractive, such an approach remains highly empiric and to some extent difficult to implement without practical guidance, in particular for the inexperienced physician. To provide a user-friendly guide for a personalized therapeutic approach to type 2 diabetes, we performed a systematic review of the literature and elaborated a simple rule that was debated at a large independent University Symposium on the occasion of the European Association for the Study of Diabetes held in Vienna 2009. As a result of that process, we now propose an A1C and ABCD of glycaemia management in type 2 diabetes to determine appropriate glycaemic targets based on Age, Body weight, Complications and Disease Duration. 'A1C and ABCD' aims to guide clinicians in the use of therapeutic agents more effectively, efficiently and safely. While no regulatory-approved drug can be excluded, given its proven efficacy, there is a need to better phenotype patients, paying particular attention to ABCD. Based on these parameters, physicians can select the therapeutic strategy with minimum risk and maximum benefit for each individual.

  15. Impact of an ABCDE team triage process combined with public guidance on the division of work in an emergency department.

    Science.gov (United States)

    Kantonen, Jarmo; Lloyd, Robert; Mattila, Juho; Kauppila, Timo; Menezes, Ricardo

    2015-06-01

    To study the effects of applying an emergency department (ED) triage system, combined with extensive publicity in local media about the "right" use of emergency services, on the division of work between ED nurses and general practitioners (GPs). An observational and quasi-experimental study based on before-after comparisons. Implementation of the ABCDE triage system in a Finnish combined ED where secondary care is adjacent, and in a traditional primary care ED where secondary care is located elsewhere. GPs and nurses from two different primary care EDs. Numbers of monthly visits to different professional groups before and after intervention in the studied primary care EDs and numbers of monthly visits to doctors in the local secondary care ED. The beginning of the triage process increased temporarily the number of independent consultations and patient record entries by ED nurses in both types of studied primary care EDs and reduced the number of patient visits to a doctor compared with previous years but had no effect on doctor visits in the adjacent secondary care ED. No further decrease in the number of nurse or GP visits was observed by inhibiting the entrance of non-urgent patients. The ABCDE triage system combined with public guidance may reduce non-urgent patient visits to doctors in different kinds of primary care EDs without increasing visits in the secondary care ED. However, the additional work to implement the ABCDE system is mainly directed to nurses, which may pose a challenge for staffing.

  16. N-alkyl functionalised expanded ring N-heterocyclic carbene complexes of rhodium(I) and iridium(I): structural investigations and preliminary catalytic evaluation.

    Science.gov (United States)

    Dunsford, Jay J; Tromp, Dorette S; Cavell, Kingsley J; Elsevier, Cornelis J; Kariuki, Benson M

    2013-05-28

    A series of new N-alkyl functionalised 6- and 7-membered expanded ring N-heterocyclic carbene (NHC) pro-ligands 3-6 and their corresponding complexes of rhodium(I) and iridium(I), [M(NHC)(COD)Cl] 7-14 and [M(NHC)(CO)2Cl] 15-22 are described. The complexes have been characterised by (1)H and (13)C{(1)H} NMR, mass spectrometry, IR and X-ray diffraction. It is noted from X-ray diffraction studies that the N-alkyl substituents are found to orientate themselves away from the metal centre due to unfavourable steric interactions resulting in low percent buried volume (%V(bur)) values in the solid state. The heterocycle ring size is also found to dictate the spatial orientation of the N-alkyl substituents in the neopentyl functionalised derivatives 10 and 14. The 7-membered derivative 14 allows for a conformational 'twist' of the heterocycle ring with the N-alkyl substituents adopting a mutually trans configuration with respect to each other, while the more rigid 6-membered system 10 does not allow for this conformational 'twist' and consequently the N-alkyl substituents adopt a mutually cis configuration. The σ-donor function of this new class of expanded ring NHC ligand has also been probed by measured IR stretching frequencies of the [M(NHC)(CO)2Cl] complexes 15-22. A preliminary catalytic survey of the hydrogenation of functionalised alkenes with molecular hydrogen under mild conditions has also been undertaken with complex , affording an insight into the application of large ring NHC ancillary ligands bearing N-alkyl substituents in hydrogenation transformations.

  17. Metabolic Flux Analysis of the Synechocystis sp. PCC 6803 ΔnrtABCD Mutant Reveals a Mechanism for Metabolic Adaptation to Nitrogen-Limited Conditions.

    Science.gov (United States)

    Nakajima, Tsubasa; Yoshikawa, Katsunori; Toya, Yoshihiro; Matsuda, Fumio; Shimizu, Hiroshi

    2017-03-01

    Metabolic flux redirection during nitrogen-limited growth was investigated in the Synechocystis sp. PCC 6803 glucose-tolerant (GT) strain under photoautotrophic conditions by isotopically non-stationary metabolic flux analysis (INST-MFA). A ΔnrtABCD mutant of Synechocystis sp. PCC 6803 was constructed to reproduce phenotypes arising during nitrogen starvation. The ΔnrtABCD mutant and the wild-type GT strain were cultured under photoautotrophic conditions by a photobioreactor. Intracellular metabolites were labeled over a time course using NaH13CO3 as a carbon source. Based on these data, the metabolic flux distributions in the wild-type and ΔnrtABCD cells were estimated by INST-MFA. The wild-type GT and ΔnrtABCD strains displayed similar distribution patterns, although the absolute levels of metabolic flux were lower in ΔnrtABCD. Furthermore, the relative flux levels for glycogen metabolism, anaplerotic reactions and the oxidative pentose phosphate pathway were increased in ΔnrtABCD. This was probably due to the increased expression of enzyme genes that respond to nitrogen depletion. Additionally, we found that the ratio of ATP/NADPH demand increased slightly in the ΔnrtABCD mutant. These results indicated that futile ATP consumption increases under nitrogen-limited conditions because the Calvin-Benson cycle and the oxidative pentose phosphate pathway form a metabolic futile cycle that consumes ATP without CO2 fixation and NADPH regeneration. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  18. Age but not ABCD(2) score predicts any level of carotid stenosis in either symptomatic or asymptomatic side in transient ischaemic attack.

    Science.gov (United States)

    Mannu, G S; Kyu, M M; Bettencourt-Silva, J H; Loke, Y K; Clark, A B; Metcalf, A K; Potter, J F; Myint, P K

    2015-09-01

    The ABCD(2) score is routinely used in assessment of transient ischaemic attack (TIA) to assess the risk of developing stroke. There remains uncertainty regarding whether the ABCD(2) score could be used to help predict extent of carotid artery stenosis (CAS). We aimed to (i) collate and analyse all available published literature on this topic and (ii) compare the data from our local population to the existing evidence base. We conducted a retrospective-observational study over a 6-month period using our East of England hospital-based TIA clinic data with a catchment population of ~750,000. We also searched the literature on studies reporting the association between ABCD(2) score and CAS. We included 341 patients in our observational study. The mean age in our cohort was 72.86 years (SD 10.91) with 52% male participants. ABCD(2) score was not significantly associated with CAS (p = 0.78). Only age > 60 years was significantly associated with ipsilateral (> 50%) and contralateral CAS (> 50% and > 70%) (p ABCD(2) score and CAS was reported, confirming our findings. Our systematic review and observational study confirm that the ABCD(2) score does not predict CAS. However, our observational study has examined a larger number of possible predictors and demonstrates that age appears to be the single best predictor of CAS in patients presenting with a TIA. Selection of urgent carotid ultrasound scan thus should be based on individual patient's age and potential benefit of carotid intervention rather than ABCD(2) score. © 2015 John Wiley & Sons Ltd.

  19. Algorithms for finite rings

    NARCIS (Netherlands)

    Ciocanea Teodorescu I.,

    2016-01-01

    In this thesis we are interested in describing algorithms that answer questions arising in ring and module theory. Our focus is on deterministic polynomial-time algorithms and rings and modules that are finite. The first main result of this thesis is a solution to the module isomorphism problem in

  20. EBT ring physics

    Energy Technology Data Exchange (ETDEWEB)

    Uckan, N.A. (ed.)

    1980-04-01

    This workshop attempted to evaluate the status of the current experimental and theoretical understanding of hot electron ring properties. The dominant physical processes that influence ring formation, scaling, and their optimal behavior are also studied. Separate abstracts were prepared for each of the 27 included papers. (MOW)

  1. Illustration of Saturn's Rings

    Science.gov (United States)

    2001-01-01

    This illustration shows a close-up of Saturn's rings. These rings are thought to have formed from material that was unable to form into a Moon because of tidal forces from Saturn, or from a Moon that was broken up by Saturn's tidal forces.

  2. Smoke Ring Physics

    Science.gov (United States)

    Huggins, Elisha

    2011-01-01

    The behavior of smoke rings, tornados, and quantized vortex rings in superfluid helium has many features in common. These features can be described by the same mathematics we use when introducing Ampere's law in an introductory physics course. We discuss these common features. (Contains 7 figures.)

  3. Imaging rings in ring imaging Cherenkov counters

    Energy Technology Data Exchange (ETDEWEB)

    Ratcliff, Blair N

    2002-11-25

    The general concepts used to form images in Ring Imaging Cherenkov (RICH) counters are described and their performance properties compared. Particular attention is paid to issues associated with imaging in the time dimension, especially in Detectors of Internally Reflected Cherenkov light (DIRCs).

  4. Rings and their modules

    CERN Document Server

    Bland, Paul E

    2011-01-01

    This book is an introduction to the theory of rings and modules that goes beyond what one normally obtains in a graduate course in abstract algebra. In addition to the presentation of standard topics in ring and module theory, it also covers category theory, homological algebra and even more specialized topics like injective envelopes and projective covers, reflexive modules and quasi-Frobenius rings, and graded rings and modules. The book is a self-contained volume written in a very systematic style: allproofs are clear and easy for the reader to understand and allarguments are based onmaterials contained in the book. A problem sets follow each section. It is suitable for graduate and PhD students who have chosen ring theory for their research subject.

  5. Saturn's Ring: Pre-Cassini Status and Mission Goals

    Science.gov (United States)

    Cuzzi, Jeff N.; DeVincenzi, Donald L. (Technical Monitor)

    1999-01-01

    In November 1980, and again in August 1981, identical Voyager spacecraft flew through the Saturn system, changing forever the way we think about planetary rings. Although Saturn's rings had been the only known ring system for three centuries, a ring system around Uranus had been discovered by stellar occultations from Earth in 1977, and the nearly transparent ring of Jupiter was imaged by Voyager in 1979 (the presence of material there had been inferred from charged particle experiments on Pioneer 10 and 11 several years earlier). While Saturn had thus temporarily lost its uniqueness as having the only ring system, with Voyager it handily recaptured the role of having the most fascinating one. The Voyager breakthroughs included spiral density and bending waves such as cause galactic structure; ubiquitous fine-scale radial 'irregular' structure, with the appearance of record-grooves; regional and local variations in particle color; complex, azimuthally variable ring structure; empty gaps in the rings, some containing very regular, sharp-edged, elliptical rings and one containing both a small moonlet and incomplete arcs of dusty material; and shadowy 'spokes' that flicker across the main rings. One of the paradigm shifts of this period was the realization that many aspects of planetary rings, and even the ring systems themselves, could be 'recent' on geological timescales. These early results are reviewed and summarized in the Arizona Space Science series volumes 'Saturn'. (An excellent review of ring dynamics at a formative stage is by Goldreich and Tremaine.) From the mid 1980's to the time of this writing, progress has been steady, while at a less heady pace, and some of the novel ring properties revealed by Voyager 1 and 2 are beginning to be better understood. It is clearly impossible to cite, much less review, every advance over the last decade; however, below we summarize the main advances in understanding of Saturn's rings since the mid 1980's, in the context

  6. Salen complexes of zirconium and hafnium: synthesis, structural characterization, controlled hydrolysis, and solvent-free ring-opening polymerization of cyclic esters and lactides.

    Science.gov (United States)

    Saha, Tanmoy Kumar; Ramkumar, Venkatachalam; Chakraborty, Debashis

    2011-04-04

    Dinuclear salen compounds of zirconium and hafnium are efficient initiators for the solvent-free ring-opening polymerization of cyclic ester monomers and lactides. There is a correlation between the theoretical and experimental number-average molecular weights (M(n)'s) in these polymerizations. Polymerization of β-butyrolactone gives poly(3-hydroxybutyrate) with a good M(n) and molecular weight distribution.

  7. The addition of E (Empowerment and Economics) to the ABCD algorithm in diabetes care.

    Science.gov (United States)

    Khazrai, Yeganeh Manon; Buzzetti, Raffaella; Del Prato, Stefano; Cahn, Avivit; Raz, Itamar; Pozzilli, Paolo

    2015-01-01

    The ABCD (Age, Body weight, Complications, Duration of disease) algorithm was proposed as a simple and practical tool to manage patients with type 2 diabetes. Diabetes treatment, as for all chronic diseases, relies on patients' ability to cope with daily problems concerning the management of their disease in accordance with medical recommendations. Thus, it is important that patients learn to manage and cope with their disease and gain greater control over actions and decisions affecting their health. Healthcare professionals should aim to encourage and increase patients' perception about their ability to take informed decisions about disease management and to improve patient self-esteem and feeling of self-efficacy to become agents of their own health. E for Empowerment is therefore an additional factor to take into account in the management of patients with type 2 diabetes. E stands also for Economics to be considered in diabetes care. Attention should be paid to public health policies as well as to the physician faced with the dilemma of delivering the best possible care within the problem of limited resources. The financial impact of the new treatment modalities for diabetes represents an issue that needs to be addressed at multiple strata both globally and nationally. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Splicing defects in ABCD1 gene leading to both exon skipping and partial intron retention in X-linked adrenoleukodystrophy Tunisian patient.

    Science.gov (United States)

    Kallabi, Fakhri; Hadj Salem, Ikhlass; Ben Chehida, Amel; Ben Salah, Ghada; Ben Turkia, Hadhami; Tebib, Neji; Keskes, Leila; Kamoun, Hassen

    2015-08-01

    X-linked adrenoleukodystrophy (X-ALD) affects the nervous system white matter and adrenal cortex secondary to mutations in the ABCD1 gene that encodes a peroxisomal membrane protein: the adrenoleukodystrophy protein. The disease is characterized by high concentrations of very long-chain fatty acids in plasma, adrenal, testicular and nervous tissues. Various types of mutations have been identified in the ABCD1 gene: point mutations, insertions, and deletions. To date, more than 40 point mutations have been reported at the splice junctions of the ABCD1 gene; only few functional studies have been performed to explore these types of mutations. In this study, we have identified de novo splice site mutation c.1780+2T>G in ABCD1 gene in an X-ALD Tunisian patient. Sequencing analysis of cDNA showed a minor transcript lacking exon 7 and a major transcript with a partial intron 7 retention due to activation of a new intronic cryptic splice site. Both outcomes lead to frameshifts with premature stop codon generation in exon 8 and intron 7 respectively. To the best of our knowledge, the current study demonstrates that a single splicing mutation affects the ABCD1 transcripts and the ALDP protein function. Copyright © 2015 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  9. Numerical studies on a plasmonic temperature nanosensor based on a metal-insulator-metal ring resonator structure for optical integrated circuit applications

    Science.gov (United States)

    Al-mahmod, Md. Jubayer; Hyder, Rakib; Islam, Md Zahurul

    2017-07-01

    A nanosensor, based on a metal-insulator-metal (MIM) plasmonic ring resonator, is proposed for potential on-chip temperature sensing and its performance is evaluated numerically. The sensor components can be fabricated by using planar processes on a silicon substrate, making its manufacturing compatible to planar electronic fabrication technology. The sensor, constructed using silver as the metal rings and a thermo-optic liquid ethanol film between the metal layers, is capable of sensing temperature with outstanding optical sensitivity, as high as -0.53 nm/°C. The resonance wavelength is found to be highly sensitive to the refractive index of the liquid dielectric film. The resonance peak can be tuned according to the requirement of intended application by changing the radii of the ring resonator geometries in the design phase. The compact size, planar and silicon-based design, and very high resolutions- these characteristics are expected to make this sensor technology a preferred choice for lab-on-a-chip applications, as compared to other contemporary sensors.

  10. Patterns of Behaviour, Group Structure and Reproductive Status Predict Levels of Glucocorticoid Metabolites in Zoo-Housed Ring-Tailed Lemurs, Lemur catta.

    Science.gov (United States)

    Smith, Tessa E; McCusker, Cara M; Stevens, Jeroen M G; Elwood, Robert W

    2015-01-01

    In ring-tailed lemurs, Lemur catta, the factors modulating hypothalamic-pituitary-adrenal (HPA) activity differ between wild and semi-free-ranging populations. Here we assess factors modulating HPA activity in ring-tailed lemurs housed in a third environment: the zoo. First we validate an enzyme immunoassay to quantify levels of glucocorticoid (GC) metabolites in the faeces of L. catta. We determine the nature of the female-female dominance hierarchies within each group by computing David's scores and examining these in relation to faecal GC (fGC). Relationships between female age and fGC are assessed to evaluate potential age-related confounds. The associations between fGC, numbers of males in a group and reproductive status are explored. Finally, we investigate the value of 7 behaviours in predicting levels of fGC. The study revealed stable linear dominance hierarchies in females within each group. The number of males in a social group together with reproductive status, but not age, influenced fGC. The 7 behavioural variables accounted for 68% of the variance in fGC. The amounts of time an animal spent locomoting and in the inside enclosure were both negative predictors of fGC. The study highlights the flexibility and adaptability of the HPA system in ring-tailed lemurs. © 2016 S. Karger AG, Basel.

  11. Saturn's Rings are Fractal

    OpenAIRE

    Li, Jun; Ostoja-Starzewski, Martin

    2012-01-01

    Over the past few decades, various conjectures were advanced that Saturn's rings are Cantor-like sets, although no convincing fractal analysis of actual images has ever appeared. We focus on the images sent by the Cassini spacecraft mission: slide #42 "Mapping Clumps in Saturn's Rings" and slide #54 "Scattered Sunshine". Using the box-counting method, we determine the fractal dimension of rings seen here (and in several other images from the same source) to be consistently about 1.6~1.7. This...

  12. Modified Newton's rings: II

    OpenAIRE

    Chaitanya, T. Sai; Kumar, Rajiv; Krishna, V. Sai; Anandh, B Shankar; Umesh, K S

    2010-01-01

    In an earlier work (Shankar kumar Jha, A Vyas, O S K S Sastri, Rajkumar Jain & K S Umesh, 'Determination of wavelength of laser light using Modified Newton's rings setup', Physics Education, vol. 22, no.3, 195-202(2005)) reported by our group, a version of Newton's rings experiment called Modified Newton's rings was proposed. The present work is an extension of this work. Here, a general formula for wavelength has been derived, applicable for a plane of observation at any distance. A relation...

  13. Ring chromosome 13

    DEFF Research Database (Denmark)

    Brandt, C A; Hertz, Jens Michael; Petersen, M B

    1992-01-01

    A stillborn male child with anencephaly and multiple malformations was found to have the karyotype 46,XY,r(13) (p11q21.1). The breakpoint at 13q21.1, determined by high resolution banding, is the most proximal breakpoint ever reported in patients with ring chromosome 13. In situ hybridisation...... with the probe L1.26 confirmed the derivation from chromosome 13 and DNA polymorphism analysis showed maternal origin of the ring chromosome. Our results, together with a review of previous reports of cases with ring chromosome 13 with identified breakpoints, could neither support the theory of distinct clinical...

  14. Faithfully quadratic rings

    CERN Document Server

    Dickmann, M

    2015-01-01

    In this monograph the authors extend the classical algebraic theory of quadratic forms over fields to diagonal quadratic forms with invertible entries over broad classes of commutative, unitary rings where -1 is not a sum of squares and 2 is invertible. They accomplish this by: (1) Extending the classical notion of matrix isometry of forms to a suitable notion of T-isometry, where T is a preorder of the given ring, A, or T = A^2. (2) Introducing in this context three axioms expressing simple properties of (value) representation of elements of the ring by quadratic forms, well-known to hold in

  15. A conceptual Saturn ring observer mission using standard radioisotope power systems

    Science.gov (United States)

    Abelson, Robert D.; Spilker, Thomas R.

    2006-01-01

    Saturn remains of the most fascinating planets within the solar system. To better understand the complex ring structure of this planet, a conceptual Saturn Ring Observer (SRO) mission is presented that would spend one year in close proximity to Saturn's A and B rings, and perform detailed observations and measurements of the ring particles and electric and magnetic fields.

  16. Particle sizes in Saturn's rings from UVIS stellar occultations 1. Variations with ring region

    Science.gov (United States)

    Colwell, J. E.; Esposito, L. W.; Cooney, J. H.

    2018-01-01

    The Cassini spacecraft's Ultraviolet Imaging Spectrograph (UVIS) includes a high speed photometer (HSP) that has observed stellar occultations by Saturn's rings with a radial resolution of ∼10 m. In the absence of intervening ring material, the time series of measurements by the HSP is described by Poisson statistics in which the variance equals the mean. The finite sizes of the ring particles occulting the star lead to a variance that is larger than the mean due to correlations in the blocking of photons due to finite particle size and due to random variations in the number of individual particles in each measurement area. This effect was first exploited by Showalter and Nicholson (1990) with the stellar occultation observed by Voyager 2. At a given optical depth, a larger excess variance corresponds to larger particles or clumps that results in greater variation of the signal from measurement to measurement. Here we present analysis of the excess variance in occultations observed by Cassini UVIS. We observe differences in the best-fitting particle size in different ring regions. The C ring plateaus show a distinctly smaller effective particle size, R, than the background C ring, while the background C ring itself shows a positive correlation between R and optical depth. The innermost 700 km of the B ring has a distribution of excess variance with optical depth that is consistent with the C ring ramp and C ring but not with the remainder of the B1 region. The Cassini Division, while similar to the C ring in spectral and structural properties, has different trends in effective particle size with optical depth. There are discrete jumps in R on either side of the Cassini Division ramp, while the C ring ramp shows a smooth transition in R from the C ring to the B ring. The A ring is dominated by self-gravity wakes whose shadow size depends on the occultation geometry. The spectral ;halo; regions around the strongest density waves in the A ring correspond to

  17. Vortex and source rings

    DEFF Research Database (Denmark)

    Branlard, Emmanuel Simon Pierre

    2017-01-01

    The velocity field, vector potential and velocity gradient of a vortex ring is derived in this chapter. The Biot-Savart law for the vector potential and velocity is expressed in a first section. Then, the flow is derived at specific locations: on the axis, near the axis and in the far field where...... the analogy to a doublet field is made. The following section derive the value of the vector potential and velocity field in the full domain. The expression for the velocity gradient is also provided since it may be relevant in a simulation with vortex particles and vortex rings. Most of this chapter...... is dedicated to vortex rings. Source rings are only briefly mentioned....

  18. The g-2 ring

    CERN Multimedia

    1974-01-01

    The precise measurement of "g-2", the anomalous magnetic moment of the muon, required a special muon storage ring with electrostatic focussing and very accurate knowledge of the magnetic bending field. For more details see under photo 7405430.

  19. Ringed Seal Distribution Map

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains GIS layers that depict the known spatial distributions (i.e., ranges) of the five subspecies of ringed seals (Phoca hispida). It was produced...

  20. Integrations on rings

    Directory of Open Access Journals (Sweden)

    Banič Iztok

    2017-04-01

    Full Text Available In calculus, an indefinite integral of a function f is a differentiable function F whose derivative is equal to f. The main goal of the paper is to generalize this notion of the indefinite integral from the ring of real functions to any ring. We also investigate basic properties of such generalized integrals and compare them to the well-known properties of indefinite integrals of real functions.

  1. Anti-leishmanial and structure-activity relationship of ring substituted 3-phenyl-1-(1,4-di-N-oxide quinoxalin-2-yl-2-propen-1-one derivatives

    Directory of Open Access Journals (Sweden)

    Asunción Burguete

    2008-12-01

    Full Text Available A series of ring substituted 3-phenyl-1-(1,4-di-N-oxide quinoxalin-2-yl-2-propen-1-one derivatives were synthesized and tested for in vitro leishmanicidal activity against amastigotes of Leishmania amazonensis in axenical cultures and murine infected macrophages. Structure-activity relationships demonstrated the importance of a radical methoxy at position R3', R4' and R5'. (2E-3-(3,4,5-trimethoxy-phenyl-1-(3,6,7-trimethyl-1,4-dioxy-quinoxalin-2-yl-propenone was the most active. Cytotoxicity on macrophages revealed that this product was almost six times more active than toxic.

  2. Seco-B-Ring Steroidal Dienynes with Aromatic D Ring: Design, Synthesis and Biological Evaluation

    Directory of Open Access Journals (Sweden)

    Marcin Szybinski

    2017-10-01

    Full Text Available Continuing our structure-activity studies on the vitamin D analogs with the altered intercyclic seco-B-ring fragment, we designed compounds possessing dienyne system conjugated with the benzene D ring. Analysis of the literature data and the docking experiments seemed to indicate that the target compounds could mimic the ligands with a good affinity to the vitamin D receptor (VDR. Multi-step synthesis of the C/D-ring building block of the tetralone structure was achieved and its enol triflate was coupled with the known A-ring fragments, possessing conjugated enyne moiety, using Sonogashira protocol. The structures of the final products were confirmed by NMR, UV and mass spectroscopy. Their binding affinities for the full-length human VDR were determined and it was established that compound substituted at C-2 with exomethylene group showed significant binding to the receptor. This analog was also able to induce monocytic differentiation of HL-60 cells.

  3. The ABCD (Alternans Before Cardioverter Defibrillator) Trial: strategies using T-wave alternans to improve efficiency of sudden cardiac death prevention.

    Science.gov (United States)

    Costantini, Otto; Hohnloser, Stefan H; Kirk, Malcolm M; Lerman, Bruce B; Baker, James H; Sethuraman, Barathi; Dettmer, Mary M; Rosenbaum, David S

    2009-02-10

    Because risk stratification with electrophysiological study (EPS) improves efficiency but is invasive, we sought to determine whether noninvasive microvolt T-wave alternans (MTWA) testing could identify patients who benefit from implantable cardioverter-defibrillators (ICDs) as well as EPS. Prevention of sudden cardiac death on the basis of left ventricular ejection fraction (LVEF) alone is inefficient, because most ICDs never deliver therapy. The ABCD (Alternans Before Cardioverter Defibrillator) trial is a multicenter prospective study that enrolled patients with ischemic cardiomyopathy (LVEF ABCD study is the first trial to use MTWA to guide prophylactic ICD insertion. Risk stratification strategies using noninvasive MTWA versus invasive EPS are comparable at 1 year and complementary when applied in combination. Strategies employing MTWA, EPS, or both might identify subsets of patients least likely to benefit from ICD insertion. (Study to Compare TWA Test and EPS Test for Predicting Patients at Risk for Life-Threatening Heart Rhythms [ABCD Study]; NCT00187291).

  4. Structure of a dinuclear cadmium complex with 2,2′-bipyridine, monodentate nitrate and 3-carboxy-6-methylpyridine-2-carboxylate ligands: intramolecular carbonyl(lone pair...π(ring and nitrate(π...π(ring interactions

    Directory of Open Access Journals (Sweden)

    Juan Granifo

    2015-08-01

    Full Text Available The centrosymmetric dinuclear complex bis(μ-3-carboxy-6-methylpyridine-2-carboxylato-κ3N,O2:O2;κ3O2:N,O2-bis[(2,2′-bipyridine-κ2N,N′(nitrato-κOcadmium] methanol monosolvate, [Cd2(C8H6NO42(NO32(C10H8N22]·CH3OH, was isolated as colourless crystals from the reaction of Cd(NO32·4H2O, 6-methylpyridine-2,3-dicarboxylic acid (mepydcH2 and 2,2′-bipyridine in methanol. The asymmetric unit consists of a CdII cation bound to a μ-κ3N,O2:O2-mepydcH− anion, an N,N′-bidentate 2,2′-bipyridine group and an O-monodentate nitrate anion, and is completed with a methanol solvent molecule at half-occupancy. The Cd complex unit is linked to its centrosymmetric image through a bridging mepydcH− carboxylate O atom to complete the dinuclear complex molecule. Despite a significant variation in the coordination angles, indicating a considerable departure from octahedral coordination geometry about the CdII atom, the Cd—O and Cd—N distances in this complex are surprisingly similar. The crystal structure consists of O—H...O hydrogen-bonded chains parallel to a, further bound by C—H...O contacts along b to form planar two-dimensional arrays parallel to (001. The juxtaposed planes form interstitial columnar voids that are filled by the methanol solvent molecules. These in turn interact with the complex molecules to further stabilize the structure. A search in the literature showed that complexes with the mepydcH− ligand are rare and complexes reported previously with this ligand do not adopt the μ-κ3 coordination mode found in the title compound.

  5. Are GOLD ABCD groups better associated with health status and costs than GOLD 1234 grades? A cross-sectional study.

    Science.gov (United States)

    Boland, Melinde R S; Tsiachristas, Apostolos; Kruis, Annemarije L; Chavannes, Niels H; Rutten-van Mölken, Maureen P M H

    2014-03-01

    To investigate the association of the GOLD ABCD groups classification with costs and health-related quality of life (HR-QoL) and to compare this with the GOLD 1234 grades classification that was primarily based on lung function only. In a cross-sectional study, we selected patients diagnosed with chronic obstructive pulmonary disease (COPD) from electronic medical records of general practices. Multi-level analysis was used with costs (medication, primary care, healthcare, societal), diseasespecific and generic HR-QoL as independent variables. Either the new or the old GOLD stages were included in the analysis together with several covariates (age, gender, living situation, co-morbidity, self-efficacy, smoking, education, employment). 611 patients from 28 general practices were categorised as GOLD-A (n=333), GOLD-B (n=110), GOLD-C (n=80) and GOLD-D (n=88). Patients in the GOLD-B and GOLD-D groups had the highest prevalence of co-morbidities and the lowest level of physical activity, self-efficacy, and employment. The models with GOLD ABCD groups were more strongly related to and explained more variance in costs and in disease-specific and generic HR-QoL than the models with GOLD 1234 grades. The mean Clinical COPD Questionnaire score worsened significantly, with scores 1.04 (GOLD-B), 0.4 (GOLD-C) and 1.21 (GOLD-D) worse than for patients in GOLD-A. Healthcare costs per patient were significantly higher in GOLD-B (72%), GOLD-C (74%) and GOLD-D (131%) patients than in GOLD-A patients. The GOLD ABCD groups classification is more closely associated with costs and HR-QoL than the GOLD 1234 grades classification. Furthermore, patients with GOLD-C had a better HR-QoL than those with GOLD-B but the costs of the two groups did not differ.

  6. Holomorphic Dynamics and Herman Rings

    DEFF Research Database (Denmark)

    Henriksen, Christian

    1997-01-01

    Existence theorem for Herman Rings of holomorphic mappings in a certain holomorphic family is given, using quasiconformal mappings. Proofs of topological properties of these Herman rings are given.......Existence theorem for Herman Rings of holomorphic mappings in a certain holomorphic family is given, using quasiconformal mappings. Proofs of topological properties of these Herman rings are given....

  7. Comparative structure analyses of cystine knot-containing molecules with eight aminoacyl ring including glycoprotein hormones (GPH alpha and beta subunits and GPH-related A2 (GPA2 and B5 (GPB5 molecules

    Directory of Open Access Journals (Sweden)

    Combarnous Yves

    2009-08-01

    Full Text Available Abstract Background Cystine-knot (cys-knot structure is found in a rather large number of secreted proteins and glycoproteins belonging to the TGFbeta and glycoprotein hormone (GPH superfamilies, many of which are involved in endocrine control of reproduction. In these molecules, the cys-knot is formed by a disulfide (SS bridge penetrating a ring formed by 8, 9 or 10 amino-acid residues among which four are cysteine residues forming two SS bridges. The glycoprotein hormones Follicle-Stimulating Hormone (FSH, Luteinizing Hormone (LH, Thyroid-Stimulating Hormone (TSH and Chorionic Gonadotropin (CG are heterodimers consisting of non-covalently associated alpha and beta subunits that possess cys-knots with 8-amino-acyl (8aa rings. In order to get better insight in the structural evolution of glycoprotein hormones, we examined the number and organization of SS bridges in the sequences of human 8-aa-ring cys-knot proteins having 7 (gremlins, 9 (cerberus, DAN, 10 (GPA2, GPB5, GPHα and 12 (GPHβ cysteine residues in their sequence. Discussion The comparison indicated that the common GPH-alpha subunit exhibits a SS bridge organization ressembling that of DAN and GPA2 but possesses a unique bridge linking an additional cysteine inside the ring to the most N-terminal cysteine residue. The specific GPHbeta subunits also exhibit a SS bridge organization close to that of DAN but it has two additional C-terminal cysteine residues which are involved in the formation of the "seat belt" fastened by a SS "buckle" that ensures the stability of the heterodimeric structure of GPHs. GPA2 and GPB5 exhibit no cys residue potentially involved in interchain SS bridge and GPB5 does not possess a sequence homologous to that of the seatbelt in GPH β-subunits. GPA2 and GPB5 are thus not expected to form a stable heterodimer at low concentration in circulation. Summary The 8-aa cys-knot proteins GPA2 and GPB5 are expected to form a heterodimer only at concentrations above 0

  8. Impaired very long-chain acyl-CoA β-oxidation in human X-linked adrenoleukodystrophy fibroblasts is a direct consequence of ABCD1 transporter dysfunction.

    Science.gov (United States)

    Wiesinger, Christoph; Kunze, Markus; Regelsberger, Günther; Forss-Petter, Sonja; Berger, Johannes

    2013-06-28

    X-linked adrenoleukodystrophy (X-ALD), an inherited peroxisomal disorder, is caused by mutations in the ABCD1 gene encoding the peroxisomal ATP-binding cassette (ABC) transporter ABCD1 (adrenoleukodystrophy protein, ALDP). Biochemically, X-ALD is characterized by an accumulation of very long-chain fatty acids and partially impaired peroxisomal β-oxidation. In this study, we used primary human fibroblasts from X-ALD and Zellweger syndrome patients to investigate the peroxisomal β-oxidation defect. Our results show that the degradation of C26:0-CoA esters is as severely impaired as degradation of unesterified very long-chain fatty acids in X-ALD and is abolished in Zellweger syndrome. Interestingly, the β-oxidation rates for both C26:0-CoA and C22:0-CoA were similarly affected, although C22:0 does not accumulate in patient fibroblasts. Furthermore, we show that the β-oxidation defect in X-ALD is directly caused by ABCD1 dysfunction as blocking ABCD1 function with a specific antibody reduced β-oxidation to levels observed in X-ALD fibroblasts. By quantification of mRNA and protein levels of the peroxisomal ABC transporters and by blocking with specific antibodies, we found that residual β-oxidation activity toward C26:0-CoA in X-ALD fibroblasts is mediated by ABCD3, although the efficacy of ABCD3 appeared to be much lower than that of ABCD1. Finally, using isolated peroxisomes, we show that β-oxidation of C26:0-CoA is independent of additional CoA but requires a cytosolic factor of >10-kDa molecular mass that is resistant to N-ethylmaleimide and heat inactivation. In conclusion, our findings in human cells suggest that, in contrast to yeast cells, very long-chain acyl-CoA esters are transported into peroxisomes by ABCD1 independently of additional synthetase activity.

  9. Impaired Very Long-chain Acyl-CoA β-Oxidation in Human X-linked Adrenoleukodystrophy Fibroblasts Is a Direct Consequence of ABCD1 Transporter Dysfunction*

    Science.gov (United States)

    Wiesinger, Christoph; Kunze, Markus; Regelsberger, Günther; Forss-Petter, Sonja; Berger, Johannes

    2013-01-01

    X-linked adrenoleukodystrophy (X-ALD), an inherited peroxisomal disorder, is caused by mutations in the ABCD1 gene encoding the peroxisomal ATP-binding cassette (ABC) transporter ABCD1 (adrenoleukodystrophy protein, ALDP). Biochemically, X-ALD is characterized by an accumulation of very long-chain fatty acids and partially impaired peroxisomal β-oxidation. In this study, we used primary human fibroblasts from X-ALD and Zellweger syndrome patients to investigate the peroxisomal β-oxidation defect. Our results show that the degradation of C26:0-CoA esters is as severely impaired as degradation of unesterified very long-chain fatty acids in X-ALD and is abolished in Zellweger syndrome. Interestingly, the β-oxidation rates for both C26:0-CoA and C22:0-CoA were similarly affected, although C22:0 does not accumulate in patient fibroblasts. Furthermore, we show that the β-oxidation defect in X-ALD is directly caused by ABCD1 dysfunction as blocking ABCD1 function with a specific antibody reduced β-oxidation to levels observed in X-ALD fibroblasts. By quantification of mRNA and protein levels of the peroxisomal ABC transporters and by blocking with specific antibodies, we found that residual β-oxidation activity toward C26:0-CoA in X-ALD fibroblasts is mediated by ABCD3, although the efficacy of ABCD3 appeared to be much lower than that of ABCD1. Finally, using isolated peroxisomes, we show that β-oxidation of C26:0-CoA is independent of additional CoA but requires a cytosolic factor of >10-kDa molecular mass that is resistant to N-ethylmaleimide and heat inactivation. In conclusion, our findings in human cells suggest that, in contrast to yeast cells, very long-chain acyl-CoA esters are transported into peroxisomes by ABCD1 independently of additional synthetase activity. PMID:23671276

  10. The ABCDE of good care: A thematic analysis on the art of caring for terminally ill patients in Malaysia

    Directory of Open Access Journals (Sweden)

    Tan Seng Beng

    2017-04-01

    Full Text Available The first and foremost requisite of caring is to treat patients as persons, not as diseases or bed-numbers. A qualitative study was conducted to explore the perception of good care from the point of view of 13 terminally ill patientsand 8 caregiving family members of the University of Malaya Medical Centre, Kuala Lumpur, Malaysia. The results were thematically analyzed. Five basic themes were generated: (1 Attitude, (2 Behaviour, (3 Communication, (4 Duty and (5 Environment—ABCDE. The results may provide useful insight into the art of caring.

  11. Something old, something new: Update of the 2009 and 2013 ABCD guidelines on prevention and management of feline infectious diseases.

    Science.gov (United States)

    Möstl, Karin; Addie, Diane D; Boucraut-Baralon, Corine; Egberink, Herman; Frymus, Tadeusz; Gruffydd-Jones, Tim; Hartmann, Katrin; Hosie, Margaret J; Lloret, Albert; Lutz, Hans; Marsilio, Fulvio; Pennisi, Maria Grazia; Radford, Alan D; Thiry, Etienne; Truyen, Uwe; Horzinek, Marian C

    2015-07-01

    The ABCD has published 34 guidelines in two Special Issues of the Journal of Feline Medicine and Surgery (JFMS): the first in July 2009 (Volume 11, Issue 7, pages 527-620) and the second in July 2013 (Volume 15, Issue 7, pages 528-652). The present article contains updates and new information on 18 of these (17 disease guidelines and one special article 'Prevention of infectious diseases in cat shelters'). For detailed information, readers are referred to the guidelines published in the above-mentioned JFMS Special Issues. © Published by SAGE on behalf of ISFM and AAFP 2015.

  12. Polyamine transporter potABCD is required for virulence of encapsulated but not nonencapsulated Streptococcus pneumoniae.

    Directory of Open Access Journals (Sweden)

    Haley R Pipkins

    Full Text Available Streptococcus pneumoniae is commonly found in the human nasopharynx and is the causative agent of multiple diseases. Since invasive pneumococcal infections are associated with encapsulated pneumococci, the capsular polysaccharide is the target of licensed pneumococcal vaccines. However, there is an increasing distribution of non-vaccine serotypes, as well as nonencapsulated S. pneumoniae (NESp. Both encapsulated and nonencapsulated pneumococci possess the polyamine oligo-transport operon (potABCD. Previous research has shown inactivation of the pot operon in encapsulated pneumococci alters protein expression and leads to a significant reduction in pneumococcal murine colonization, but the role of the pot operon in NESp is unknown. Here, we demonstrate deletion of potD from the NESp NCC1 strain MNZ67 does impact expression of the key proteins pneumolysin and PspK, but it does not inhibit murine colonization. Additionally, we show the absence of potD significantly increases biofilm production, both in vitro and in vivo. In a chinchilla model of otitis media (OM, the absence of potD does not significantly affect MNZ67 virulence, but it does significantly reduce the pathogenesis of the virulent encapsulated strain TIGR4 (serotype 4. Deletion of potD also significantly reduced persistence of TIGR4 in the lungs but increased persistence of PIP01 in the lungs. We conclude the pot operon is important for the regulation of protein expression and biofilm formation in both encapsulated and NCC1 nonencapsulated Streptococcus pneumoniae. However, in contrast to encapsulated pneumococcal strains, polyamine acquisition via the pot operon is not required for MNZ67 murine colonization, persistence in the lungs, or full virulence in a model of OM. Therefore, NESp virulence regulation needs to be further established to identify potential NESp therapeutic targets.

  13. Cardiac Autonomic Nervous System Activation and Metabolic Profile in Young Children: The ABCD Study.

    Science.gov (United States)

    Vrijkotte, Tanja G M; van den Born, Bert-Jan H; Hoekstra, Christine M C A; Gademan, Maaike G J; van Eijsden, Manon; de Rooij, Susanne R; Twickler, Marcel T B

    2015-01-01

    In adults, increased sympathetic and decreased parasympathetic nervous system activity are associated with a less favorable metabolic profile. Whether this is already determined at early age is unknown. Therefore, we aimed to assess the association between autonomic nervous system activation and metabolic profile and its components in children at age of 5-6 years. Cross-sectional data from an apparently healthy population (within the ABCD study) were collected at age 5-6 years in 1540 children. Heart rate (HR), respiratory sinus arrhythmia (RSA; parasympathetic activity) and pre-ejection period (PEP; sympathetic activity) were assessed during rest. Metabolic components were waist-height ratio (WHtR), systolic blood pressure (SBP), fasting triglycerides, glucose and HDL-cholesterol. Individual components, as well as a cumulative metabolic score, were analyzed. In analysis adjusted for child's physical activity, sleep, anxiety score and other potential confounders, increased HR and decreased RSA were associated with higher WHtR (P< 0.01), higher SBP (p<0.001) and a higher cumulative metabolic score (HR: p < 0.001; RSA: p < 0.01). Lower PEP was only associated with higher SBP (p <0.05). Of all children, 5.6% had 3 or more (out of 5) adverse metabolic components; only higher HR was associated with this risk (per 10 bpm increase: OR = 1.56; p < 0.001). This study shows that decreased parasympathetic activity is associated with central adiposity and higher SBP, indicative of increased metabolic risk, already at age 5-6 years.

  14. ABCD classification system: a novel classification for subaxial cervical spine injuries.

    Science.gov (United States)

    Shousha, Mootaz

    2014-04-20

    The classification system was derived through a retrospective analysis of 73 consecutive cases of subaxial cervical spine injury as well as thorough literature review. To define a new classification system for subaxial cervical spine injuries. There exist several methods to classify subaxial cervical spine injuries but no single system has emerged as clearly superior to the others. On the basis of a 2-column anatomical model, the first part of the proposed classification is an anatomical description of the injury. It delivers the information whether the injury is bony, ligamentous, or a combined one. The first 4 alphabetical letters have been used for simplicity. Each column is represented by an alphabetical letter from A to D. Each letter has a radiological meaning (A = Absent injury, B = Bony lesion, C = Combined bony and ligamentous, D = Disc or ligamentous injury).The second part of the classification is represented by 3 modifiers. These are the neurological status of the patient (N), the degree of spinal canal stenosis (S), and the degree of instability (I). For simplicity, each modifier was graded in an ascending pattern of severity from zero to 2. The last part is optional and denotes which radiological examination has been used to define the injury type. The new ABCD classification was applicable for all patients. The most common type was anterior ligamentous and posterior combined injury "DC" (37.9%), followed by "DD" injury in 12% of the cases. Through this work a new classification for cervical spine injuries is proposed. The aim is to establish criteria for a common language in description of cervical injuries aiming for simplification, especially for junior residents. Each letter and each sign has a meaning to deliver the largest amount of information. Both the radiological as well as the clinical data are represented in this scheme. However, further evaluation of this classification is needed. 3.

  15. Factors associated with circulating concentrations of irisin in the general population cohort of the ABCD study.

    Science.gov (United States)

    Buscemi, S; Corleo, D; Vasto, S; Buscemi, C; Massenti, M F; Nuzzo, D; Lucisano, G; Barile, A M; Rosafio, G; Maniaci, V; Giordano, C

    2017-10-13

    Animal studies have shown that irisin is a myokine secreted following physical exercise, and that it induces the remodeling of white adipose tissue toward brown adipose tissue. Therefore, a protective role of irisin against obesity, diabetes, and other metabolic and cardiovascular conditions has been hypothesized. However, data in humans are contradictory and few data are available concerning the general population. We aimed to evaluate the association between serum irisin concentrations and habitual physical activity, as well as other metabolic and cardiovascular factors in a general population in a Mediterranean area. We considered 858 consecutive individuals included in the ABCD (Alimentazione, Benessere Cardiovascolare e Diabete) study (ISRCTN15840340), a longitudinal observational single-center study of a cohort representative of the general population of Palermo, Sicily. Irisin serum concentrations (Phoenix Europe, Germany), habitual physical activity (HPA) level, and other blood and clinical variables were measured. The irisin serum concentrations were not normally distributed in the cohort (Shapiro-Wilk test=0.94; P<0.001). A significant association between irisin concentrations and HPA was observed (P<0.001). Irisin concentrations were higher in women than in men (P<0.01), and significantly correlated with serum concentrations of HDL-cholesterol (P<0.05) and hs-C-reactive protein (hs-CRP; P<0.05). Binary logistic regression analysis demonstrated that high (⩾median value) irisin serum concentrations were significantly associated with female gender (OR=1.63; 95%CI=1.16-2.28), high serum hs-CRP concentrations (OR=1.61; 95%CI=1.02-2.54) and the HPA level (OR=1.42; 95%CI=1.02-1.96). Our study confirms, in a cohort of a general population, that irisin concentrations gradually increase with the usual level of habitual physical activity.International Journal of Obesity accepted article preview online, 13 October 2017. doi:10.1038/ijo.2017.255.

  16. Schatzki ring, statistically reexamined.

    Science.gov (United States)

    Pezzullo, John C; Lewicki, Ann M

    2003-09-01

    In the article by Schatzki published in 1963, data about the lower esophageal ring relate ring diameter to presence of dysphagia. Statistical analysis of these measurements was performed to quantify conclusions of Schatzki and to extract additional information from the data. Ring diameters in 332 patients with and without dysphagia are described in a histogram in the original article of Schatzki. Data were evaluated with analysis of variance, logistic regression, and receiver operating characteristic (ROC) analysis to quantify the relationship between ring diameter and dysphagia. Follow-up information was available in 36 symptomatic and 30 asymptomatic patients of Schatzki. Logistic regression indicated that there was a highly significant difference in ring diameter between the asymptomatic group and patients with recurrent dysphagia (P Schatzki had a 96% (104 of 108) sensitivity and a 58% (130 of 224) specificity, with area under the ROC curve of 0.888. Retrospective statistical analysis of original data of Schatzki validated his major conclusions about the data. Some important questions remain unanswered because of missing data in the study of Schatzki. Copyright RSNA, 2003

  17. On the evolution of vortex rings with swirl

    Energy Technology Data Exchange (ETDEWEB)

    Naitoh, Takashi, E-mail: naitoh.takashi@nitech.ac.jp [Department of Engineering Physics, Electronics and Mechanics, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Okura, Nobuyuki, E-mail: ohkura@meijo-u.ac.jp [Department of Vehicle and Mechanical Engineering, Meijo University, 1-501 Shiogamaguchi Tempaku-ku, Nagoya 468-8502 (Japan); Gotoh, Toshiyuki, E-mail: gotoh.toshiyuki@nitech.ac.jp [Department of Scientific and Engineering Simulation, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Kato, Yusuke [Controller Business Unit Engineering Division 1, Engineering Department 3, Denso Wave Incorporated, 1 Yoshiike Kusagi Agui-cho, Chita-gun Aichi 470-2297 (Japan)

    2014-06-15

    A laminar vortex ring with swirl, which has the meridional velocity component inside the vortex core, was experimentally generated by the brief fluid ejection from a rotating outlet. The evolution of the vortex ring was investigated with flow visualizations and particle image velocimetry measurements in order to find the influence of swirling flow in particular upon the transition to turbulence. Immediately after the formation of a vortex ring with swirl, a columnar strong vortex along the symmetric axis is observed in all cases of the present experiment. Then the characteristic fluid discharging from a vortex ring with swirl referred to as “peeling off” appears. The amount of discharging fluid due to the “peeling off” increases with the angular velocity of the rotating outlet. We conjectured that the mechanism generating the “peeling off” is related to the columnar strong vortex by close observations of the spatio-temporal development of the vorticity distribution and the cutting 3D images constructed from the successive cross sections of a vortex ring. While a laminar vortex ring without swirl may develop azimuthal waves around its circumference at some later time and the ring structure subsequently breaks, the swirling flow in a vortex ring core reduces the amplification rate of the azimuthal wavy deformation and preserved its ring structure. Then the traveling distance of a vortex ring can be extended using the swirl flow under certain conditions.

  18. Oligomeric ferrocene rings

    Science.gov (United States)

    Inkpen, Michael S.; Scheerer, Stefan; Linseis, Michael; White, Andrew J. P.; Winter, Rainer F.; Albrecht, Tim; Long, Nicholas J.

    2016-09-01

    Cyclic oligomers comprising strongly interacting redox-active monomer units represent an unknown, yet highly desirable class of nanoscale materials. Here we describe the synthesis and properties of the first family of molecules belonging to this compound category—differently sized rings comprising only 1,1‧-disubstituted ferrocene units (cyclo[n], n = 5-7, 9). Due to the close proximity and connectivity of centres (covalent Cp-Cp linkages; Cp = cyclopentadienyl) solution voltammograms exhibit well-resolved, separated 1e- waves. Theoretical interrogations into correlations based on ring size and charge state are facilitated using values of the equilibrium potentials of these transitions, as well as their relative spacing. As the interaction free energies between the redox centres scale linearly with overall ring charge and in conjunction with fast intramolecular electron transfer (˜107 s-1), these molecules can be considered as uniformly charged nanorings (diameter ˜1-2 nm).

  19. Decay ring design

    CERN Document Server

    Chancé, A; Bouquerel, E; Hancock, S; Jensen, E

    The study of the neutrino oscillation between its different flavours needs pureand very intense fluxes of high energy, well collimated neutrinos with a welldetermined energy spectrum. A dedicated machine seems to be necessarynowadays to reach the required flux. A new concept based on the β-decayof radioactive ions which were accelerated in an accelerator chain was thenproposed. After ion production, stripping, bunching and acceleration, the unstableions are then stored in a racetrack-shaped superconducting decay ring.Finally, the ions are accumulated in the decay ring until being lost. The incomingbeam is merged to the stored beam by using a specific RF system, whichwill be presented here.We propose here to study some aspects of the decay ring, such as its opticalproperties, its RF system or the management of the losses which occur in thering (mainly by decay or by collimation).

  20. Den mindst ringe verdensorden

    DEFF Research Database (Denmark)

    Hansen, Birthe

    2015-01-01

    I 25 år har USA's styrkeposition og politik forsynet os med en 'verdensorden', der i et historisk perspektiv fremstår som den mindst ringe: fravær af store krige, mere demokrati, økonomisk fremgang - men dog også sammenbrudte stater og terrorisme.......I 25 år har USA's styrkeposition og politik forsynet os med en 'verdensorden', der i et historisk perspektiv fremstår som den mindst ringe: fravær af store krige, mere demokrati, økonomisk fremgang - men dog også sammenbrudte stater og terrorisme....

  1. Electrothermal Ring Burn

    Directory of Open Access Journals (Sweden)

    Yakup Çil

    2012-09-01

    Full Text Available Low-voltage fountainheads such as car, tractor or motorcycle batteries are predisposed to produce large currents. Any metal object that comes into contact with these batteries may result in short-circuit. This may result in rapid and excessive heating of metal object and an electrothermal burn. Herein we presented a motorcycle driver who was 28-year-old man with electrothermal ring burn which was caused by metal chain that was used as a ring. (Turk J Dermatol 2012; 6: 106-7

  2. Saturn's Rings, the Yarkovsky Effects, and the Ring of Fire

    Science.gov (United States)

    Rubincam, David Parry

    2004-01-01

    The dimensions of Saturn's A and B rings may be determined by the seasonal Yarkovsky effect and the Yarkovsky-Schach effect; the two effects confine the rings between approximately 1.68 and approximately 2.23 Saturn radii, in reasonable agreement with the observed values of 1.525 and 2.267. The C ring may be sparsely populated because its particles are transients on their way to Saturn; the infall may create a luminous Ring of Fire around Saturn's equator. The ring system may be young: in the past heat flow from Saturn's interior much above its present value would not permit rings to exist.

  3. A de-novo large deletion of 2.8 kb produced in the ABCD1 gene causing adrenoleukodystrophy disease.

    Science.gov (United States)

    Kallabi, Fakhri; Ben Salah, Ghada; Ben Chehida, Amel; Tabebi, Mouna; Felhi, Rahma; Ben Turkia, Hadhami; Tebib, Neji; Keskes, Leila; Kamoun, Hassen

    2016-06-01

    X-linked adrenoleukodystrophy (X-ALD) is a neurodegenerative disorder caused by mutations in the ABCD1 gene, which encodes an ATP-binding cassette transporter protein, ALDP. The disease is characterized by increased concentrations of very long chain fatty acids (VLCFAs) in plasma, adrenal, testicular, and nerve tissues. For this study, our objective was to conduct clinical, molecular, and genetic studies of a Tunisian patient with X-ALD. The diagnosis was based on clinical indications, biochemical analyses, typical brain-scan patterns, and molecular biology; the molecular analyses were based on PCR, long-range PCR, and sequencing. The molecular analysis by long-range PCR and direct sequencing of the ABCD1 gene showed the presence of a de-novo 2794 bp deletion covering the whole of exon 2. Using bioinformatics tools, we demonstrate that the large deletion is located in a region rich with Alu sequences. Furthermore, we suggest that the AluJb sequence could be the cause of the large deletion of intron 1, exon 2, and intron 2, and the creation of a premature stop codon within exon 3. This report is the first report in which we demonstrate the breakpoints and the size of a large deletion in a Tunisian with X-ALD.

  4. Architecture for an advanced biomedical collaboration domain for the European paediatric cancer research community (ABCD-4-E).

    Science.gov (United States)

    Nitzlnader, Michael; Falgenhauer, Markus; Gossy, Christian; Schreier, Günter

    2015-01-01

    Today, progress in biomedical research often depends on large, interdisciplinary research projects and tailored information and communication technology (ICT) support. In the context of the European Network for Cancer Research in Children and Adolescents (ENCCA) project the exchange of data between data source (Source Domain) and data consumer (Consumer Domain) systems in a distributed computing environment needs to be facilitated. This work presents the requirements and the corresponding solution architecture of the Advanced Biomedical Collaboration Domain for Europe (ABCD-4-E). The proposed concept utilises public as well as private cloud systems, the Integrating the Healthcare Enterprise (IHE) framework and web-based applications to provide the core capabilities in accordance with privacy and security needs. The utility of crucial parts of the concept was evaluated by prototypic implementation. A discussion of the design indicates that the requirements of ENCCA are fully met. A whole system demonstration is currently being prepared to verify that ABCD-4-E has the potential to evolve into a domain-bridging collaboration platform in the future.

  5. Structure-Activity Analysis of Gram-positive Bacterium-producing Lasso Peptides with Anti-mycobacterial Activity

    Science.gov (United States)

    Inokoshi, Junji; Koyama, Nobuhiro; Miyake, Midori; Shimizu, Yuji; Tomoda, Hiroshi

    2016-07-01

    Lariatin A, an 18-residue lasso peptide encoded by the five-gene cluster larABCDE, displays potent and selective anti-mycobacterial activity. The structural feature is an N-terminal macrolactam ring, through which the C-terminal passed to form the rigid lariat-protoknot structure. In the present study, we established a convergent expression system by the strategy in which larA mutant gene-carrying plasmids were transformed into larA-deficient Rhodococcus jostii, and generated 36 lariatin variants of the precursor protein LarA to investigate the biosynthesis and the structure-activity relationships. The mutational analysis revealed that four amino acid residues (Gly1, Arg7, Glu8, and Trp9) in lariatin A are essential for the maturation and production in the biosynthetic machinery. Furthermore, the study on structure-activity relationships demonstrated that Tyr6, Gly11, and Asn14 are responsible for the anti-mycobacterial activity, and the residues at positions 15, 16 and 18 in lariatin A are critical for enhancing the activity. This study will not only provide a useful platform for genetically engineering Gram-positive bacterium-producing lasso peptides, but also an important foundation to rationally design more promising drug candidates for combatting tuberculosis.

  6. The Vibration Ring. Phase 1; [Seedling Fund

    Science.gov (United States)

    Asnani, Vivake M.; Krantz, Timothy L.; Delap, Damon C.; Stringer, David B.

    2014-01-01

    The vibration ring was conceived as a driveline damping device to prevent structure-borne noise in machines. It has the appearance of a metal ring, and can be installed between any two driveline components like an ordinary mechanical spacer. Damping is achieved using a ring-shaped piezoelectric stack that is poled in the axial direction and connected to an electrical shunt circuit. Surrounding the stack is a metal structure, called the compression cage, which squeezes the stack along its poled axis when excited by radial driveline forces. The stack in turn generates electrical energy, which is either dissipated or harvested using the shunt circuit. Removing energy from the system creates a net damping effect. The vibration ring is much stiffer than traditional damping devices, which allows it to be used in a driveline without disrupting normal operation. In phase 1 of this NASA Seedling Fund project, a combination of design and analysis was used to examine the feasibility of this concept. Several designs were evaluated using solid modeling, finite element analysis, and by creating prototype hardware. Then an analytical model representing the coupled electromechanical response was formulated in closed form. The model was exercised parametrically to examine the stiffness and loss factor spectra of the vibration ring, as well as simulate its damping effect in the context of a simplified driveline model. The results of this work showed that this is a viable mechanism for driveline damping, and provided several lessons for continued development.

  7. Storage Ring EDM Experiments

    Directory of Open Access Journals (Sweden)

    Semertzidis Yannis K.

    2016-01-01

    Full Text Available Dedicated storage ring electric dipole moment (EDM methods show great promise advancing the sensitivity level by a couple orders of magnitude over currently planned hadronic EDM experiments. We describe the present status and recent updates of the field.

  8. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Stroppel, Catharina

    2012-01-01

    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from [12] and give a similar description of the sp2n-fusion ring in terms of noncommutative symmetric...... functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also compute the fu- sion rings for type G2....

  9. Cassini Imaging Science: initial results on Saturn's rings and small satellites.

    Science.gov (United States)

    Porco, C C; Baker, E; Barbara, J; Beurle, K; Brahic, A; Burns, J A; Charnoz, S; Cooper, N; Dawson, D D; Del Genio, A D; Denk, T; Dones, L; Dyudina, U; Evans, M W; Giese, B; Grazier, K; Helfenstein, P; Ingersoll, A P; Jacobson, R A; Johnson, T V; McEwen, A; Murray, C D; Neukum, G; Owen, W M; Perry, J; Roatsch, T; Spitale, J; Squyres, S; Thomas, P; Tiscareno, M; Turtle, E; Vasavada, A R; Veverka, J; Wagner, R; West, R

    2005-02-25

    Images acquired of Saturn's rings and small moons by the Cassini Imaging Science Subsystem (ISS) during the first 9 months of Cassini operations at Saturn have produced many new findings. These include new saturnian moons; refined orbits of new and previously known moons; narrow diffuse rings in the F-ring region and embedded in gaps within the main rings; exceptionally fine-scale ring structure in moderate- to high-optical depth regions; new estimates for the masses of ring-region moons, as well as ring particle properties in the Cassini division, derived from the analysis of linear density waves; ring particle albedos in select ring regions; and never-before-seen phenomena within the rings.

  10. A REPORT ON ABCD ACTIVITIES SEPTEMBER, 1963 - AUGUST, 1964. TO THE FORD FOUNDATION AND THE PRESIDENT'S COMMITTEE ON JUVENILE DELINQUENCY AND YOUTH CRIME.

    Science.gov (United States)

    Action for Boston Community Development, Inc., MA.

    DURING THE PERIOD UNDER REVIEW, ABCD WAS ENGAGED IN PROGRAM ELABORATION AND IMPLEMENTATION, ESPECIALLY IN CONJUNCTION WITH THE BOSTON YOUTH OPPORTUNITIES PROJECT. IT HAS ATTEMPTED TO MOVE FROM HOPES AND IDEAS TO TANGIBLE OPERATIONS, TO INSURE THAT CHANGE TAKES PLACE AND TO DESIGN PROGRAMS WITH SUFFICIENT CLARITY SO THAT THEIR USEFULNESS CAN BE…

  11. Ring Bubbles of Dolphins

    Science.gov (United States)

    Shariff, Karim; Marten, Ken; Psarakos, Suchi; White, Don J.; Merriam, Marshal (Technical Monitor)

    1996-01-01

    The article discusses how dolphins create and play with three types of air-filled vortices. The underlying physics is discussed. Photographs and sketches illustrating the dolphin's actions and physics are presented. The dolphins engage in this behavior on their own initiative without food reward. These behaviors are done repeatedly and with singleminded effort. The first type is the ejection of bubbles which, after some practice on the part of the dolphin, turn into toroidal vortex ring bubbles by the mechanism of baroclinic torque. These bubbles grow in radius and become thinner as they rise vertically to the surface. One dolphin would blow two in succession and guide them to fuse into one. Physicists call this a vortex reconnection. In the second type, the dolphins first create an invisible vortex ring in the water by swimming on their side and waving their tail fin (also called flukes) vigorously. This vortex ring travels horizontally in the water. The dolphin then turns around, finds the vortex and injects a stream of air into it from its blowhole. The air "fills-out" the core of the vortex ring. Often, the dolphin would knock-off a smaller ring bubble from the larger ring (this also involves vortex reconnection) and steer the smaller ring around the tank. One other dolphin employed a few other techniques for planting air into the fluke vortex. One technique included standing vertically in the water with tail-up, head-down and tail piercing the free surface. As the fluke is waved to create the vortex ring, air is entrained from above the surface. Another technique was gulping air in the mouth, diving down, releasing air bubbles from the mouth and curling them into a ring when they rose to the level of the fluke. In the third type, demonstrated by only one dolphin, the longitudinal vortex created by the dorsal fin on the back is used to produce 10-15 foot long helical bubbles. In one technique she swims in a curved path. This creates a dorsal fin vortex since

  12. The influence of water on visible-light initiated free-radical/cationic ring-opening hybrid polymerization of methacrylate/epoxy: Polymerization kinetics, crosslinking structure and dynamic mechanical properties.

    Science.gov (United States)

    Ge, Xueping; Ye, Qiang; Song, Linyong; Misra, Anil; Spencer, Paulette

    The objective of this study was to determine the influence of water on the polymerization kinetics, crosslinking structure and dynamic mechanical properties of methacrylate/epoxy polymers cured by visible-light initiated free-radical/cationic ring-opening hybrid polymerization. Water-containing formulations were prepared by adding ~4-7 wt% D 2 O depending on the water miscibility of monomer resins. The water-containing adhesives were compared with the adhesives photo-cured in the absence of water. The results show an improved degree of conversion for both methacrylates and epoxy by adding water. The rate of the epoxy cationic ring-opening reaction is increased while the rate of free radical polymerization is decreased in the presence of water. The decreased crosslinking density noted in the presence of water suggests that the chain transfer reaction between water and epoxy competes with the hydroxyl-based chain transfer mechanism. There is potential application of this visible-light initiated hybrid polymerization in biomaterials, e.g. dental restorations and tissue engineering scaffolds.

  13. Ring-shaped velocity distribution functions in energy-dispersed structures formed at the boundaries of a proton stream injected into a transverse magnetic field: Test-kinetic results

    CERN Document Server

    Voitcu, Gabriel

    2016-01-01

    In this paper, we discuss the formation of ring-shaped and gyro-phase restricted velocity distribution functions (VDFs) at the edges of a cloud of protons injected into non-uniform distributions of the electromagnetic field. The velocity distribution function is reconstructed using the forward test-kinetic method. We consider two profiles of the electric field: (1) a non-uniform E-field obtained by solving the Laplace equation consistent with the conservation of the electric drift and (2) a constant and uniform E-field. In both cases, the magnetic field is similar to the solutions obtained for tangential discontinuities. The initial velocity distribution function is Liouville mapped along numerically integrated trajectories. The numerical results show the formation of an energy-dispersed structure due to the energy-dependent displacement of protons towards the edges of the cloud by the gradient-B drift. Another direct effect of the gradient-B drift is the formation of ring-shaped velocity distribution functio...

  14. Saturn ring temperature changes before and after ring equinox

    Science.gov (United States)

    Spilker, Linda; Flandes, Alberto; Morishima, Ryuji; Leyrat, Cedric; Altobelli, Nicolas; Ferrari, Cecile; Brooks, Shawn; Pilorz, Stu

    2010-05-01

    The Cassini Composite infrared spectrometer (CIRS) retrieved the temperatures of Saturn's main rings at solar elevations ranging from 24 degrees to zero degrees at equinox (August 2009) as the sun traversed from the south to north side of the rings. Over this broad range of solar elevation the CIRS data show that the ring temperatures vary as much as 29K- 38K for the A ring, 22K-34K for the B ring and 18K-23K for the C ring. Interestingly the unlit sides of the rings show a similar decrease in temperature with the decreasing solar elevation. As equinox approached, the main rings cooled to their lowest temperatures measured to date. At equinox the solar input is very small and the primary heat sources for the rings are Saturn thermal and visible energy. Temperatures are almost identical for similar geometries on the north and south sides of the rings. The ring temperatures at equinox were: C ring, 55-75 K; B ring, 45-60 K; Cassini Division, 45 - 58 K; and A ring, 43 - 52 K. After Saturn equinox the solar elevation angle began to increase again and the temperatures on both the lit (north) and unlit (south) sides of the rings have begun to increase as well. Ring thermal models developed by Flandes and Morishima are able to reproduce most of the equinox temperatures observed by CIRS. Results before and after equinox will be presented. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA and at CEA Saclay supported by the "Programme National de Planetologie". Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

  15. Voyager Observations of the Color of Saturn's Ring

    Science.gov (United States)

    Estrada, Paul R.; Cuzzi, Jeffrey N.; Morrison, David (Technical Monitor)

    1994-01-01

    Previously unreduced high resolution Voyager 2 images of Saturn's main rings are used to generate reflectivity (I/F) profiles as a function of radius. Ratios of profiles taken from green, violet, orange, and UV filter images are then produced. The I/F ratios are diagnostic of composition, and provide us with information on the rings' present state of compositional evolution. The rings are extremely reddish in color which suggests that they could not be pure water ice. The most likely candidates for the non-icy components are silicates and organics. The sources of these pollutants are of extreme importance in determining the compositional history of the rings. The radial profiles of ring color ratio exhibit several very interesting properties: (a) broad-scale, fairly smooth, color variations which are only weakly correlated with underlying ring structure (optical depth variations) across the outer C ring and inner B ring as well as the Cassini division region. These variations are probably consistent with ballistic transport; (b) fine-scale, noise-Like (but unquestionably real) color variations across at least the outer two-thirds of the B ring. Not only the "redness" but the spectral shape varies. These variations are currently unexplained. Groundbased spectroscopic observations should be pursued to study the implied compositional heterogeneities on at least the larger scales. This data set will be used for modeling of the color and composition of the main rings using ballistic transport and radiative transfer theories.

  16. Stellar Occultation by Saturn's Rings in the UV

    Science.gov (United States)

    Becker, Tracy

    2017-08-01

    We propose to capitalize on the unique opportunity to observe the July 2018 stellar occultation of the star HD 168233 by Saturn's rings using the COS G230L mode on HST. Our program will characterize the particle size distribution of the rings through analyses of the starlight diffracted by the ring particles. It will also define the shape and structure of the rings through measurements of the optical depth of the variable F ring, the characterization of the self-gravity wakes, and by constraining the A ring edge dynamics six months after the radial swap of the co-orbital moons Janus and Epimetheus, which maintain the ring's outer edge. Saturn's rings are very dark at UV wavelengths; therefore, stellar occultations in the UV have a significantly lower background signal from the ring-reflected sunlight than at longer wavelengths. Furthermore, occultations at UV wavelengths are sensitive to the smallest particles in the rings. The geometry and wavelengths of the stellar occultation from HST COS will complement and extend the science return from the Cassini spacecraft nearly one year after the mission's end.

  17. PREFACE: Special section on vortex rings Special section on vortex rings

    Science.gov (United States)

    Fukumoto, Yasuhide

    2009-10-01

    This special section of Fluid Dynamics Research includes five articles on vortex rings in both classical and quantum fluids. The leading scientists of the field describe the trends in and the state-of-the-art development of experiments, theories and numerical simulations of vortex rings. The year 2008 was the 150th anniversary of 'vortex motion' since Hermann von Helmholtz opened up this field. In 1858, Helmholtz published a paper in Crelle's Journal which put forward the concept of 'vorticity' and made the first analysis of vortex motion. Fluid mechanics before that was limited to irrotational motion. In the absence of vorticity, the motion of an incompressible homogeneous fluid is virtually equivalent to a rigid-body motion in the sense that the fluid motion is determined once the boundary configuration is specified. Helmholtz proved, among other things, that, without viscosity, a vortex line is frozen into the fluid. This Helmholtz's law immediately implies the preservation of knots and links of vortex lines and its implication is enormous. One of the major trends of fluid mechanics since the latter half of the 20th century is to clarify the topological meaning of Helmholtz's law and to exploit it to develop theoretical and numerical methods to find the solutions of the Euler equations and to develop experimental techniques to gain an insight into fluid motion. Vortex rings are prominent coherent structures in a variety of fluid motions from the microscopic scale, through human and mesoscale to astrophysical scales, and have attracted people's interest. The late professor Philip G Saffman (1981) emphasized the significance of studies on vortex rings. One particular motion exemplifies the whole range of problems of vortex motion and is also a commonly known phenomenon, namely the vortex ring or smoke ring. Vortex rings are easily produced by dropping drops of one liquid into another, or by puffing fluid out of a hole, or by exhaling smoke if one has the skill

  18. Density-functional calculations of magnetoplasmons in quantum rings

    Science.gov (United States)

    Emperador, A.; Barranco, M.; Lipparini, E.; Pi, M.; Serra, Ll.

    1999-06-01

    We have studied the structure and dipole charge-density response of nanorings as a function of the magnetic field using local-spin-density-functional theory. Two small rings consisting of 12 and 22 electrons confined by a positively charged background are used to represent the cases of narrow and wide rings. The results are qualitatively compared with experimental data existing on microrings and on antidots. A smaller ring containing five electrons is also analyzed to allow for a closer comparison with a recent experiment on a two-electron quantum ring.

  19. Direct detection of gaps in Saturn's A ring

    Science.gov (United States)

    Rehnberg, Morgan E.; Brown, Zarah L.; Esposito, Larry W.; Albers, Nicole

    2017-11-01

    Indirect observations spanning decades have indicated that Saturn's A ring is populated with a plethora of self-gravity wakes, small wavelike structures that arise from the gravitational attraction between ring particles. We present the direct detection of the gaps that represent the minima between the denser wakes. Through a statistical test, we analyze a series of seven high-resolution stellar occultations observed by the Cassini Ultraviolet Imaging Spectrograph to identify nearly half a million discrete regions with an optical depth less than a quarter of the surrounding ring. These gaps correlate strongly with previous observations of the A-ring brightness asymmetry.

  20. Role Of Computational Simulations In The Design Of Piston Rings

    Directory of Open Access Journals (Sweden)

    Novotný Pavel

    2015-06-01

    Full Text Available The paper presents computational approaches using modern strategies for a dynamic piston ring solution as a fluid structural problem. Computational model outputs can be used to understand design parameter influences on defined results of a primarily integral character. Piston ring dynamics incorporates mixed lubrication conditions, the influence of surface roughness on oil film lubrication, the influence of ring movement on gas dynamics, oil film formulation on a cylinder liner and other significant influences. The solution results are presented for several parameters of SI engine piston rings.

  1. The LI-rings in pollen tubes

    Directory of Open Access Journals (Sweden)

    H. Q. Zhang

    2014-01-01

    Full Text Available Monoclonal antibodies, which recognize the specific epitopes for pectins and arabinogalactan proteins, in connection with confocal laser scanning microscopy demonstrated the presence of a ring-like structure in the cell wall of pollen tubes of flowering plants.

  2. Nuclear physics experiments with ion storage rings

    NARCIS (Netherlands)

    Litvinov, Yu. A.; Bishop, S.; Blaum, K.; Bosch, F.; Brandau, C.; Chen, L. X.; Dillmann, I.; Egelhof, P.; Geissel, H.; Grisenti, R. E.; Hagmann, S.; Heil, M.; Heinz, A.; Kalantar-Nayestanaki, N.; Knoebel, R.; Kozhuharov, C.; Lestinsky, M.; Ma, X. W.; Nilsson, T.; Nolden, F.; Ozawa, A.; Raabe, R.; Reed, M. W.; Reifarth, R.; Sanjari, M. S.; Schneider, D.; Simon, H.; Steck, M.; Stoehlker, T.; Sun, B. H.; Tu, X. L.; Uesaka, T.; Walker, P. M.; Wakasugi, M.; Weick, H.; Winckler, N.; Woods, P. J.; Xu, H. S.; Yamaguchi, T.; Yamaguchi, Y.; Zhang, Y. H.

    2013-01-01

    In the last two decades a number of nuclear structure and astrophysics experiments were performed at heavy-ion storage rings employing unique experimental conditions offered by such machines. Furthermore, building on the experience gained at the two facilities presently in operation, several new

  3. Geochemical characterization of gases in the deep hole of the siljan ring structure, Sweden: Chemical analysis of the black material. Topical report, October 25, 1988

    Energy Technology Data Exchange (ETDEWEB)

    1988-10-25

    Results of the analyses of the black material recovered from a well in the Siljan Ring and the interpretation of the origin of the black material are presented. The report focuses on the non-mineral component of the black material, since the mineral component, magnetite with trace amounts of quartz and feldspar, was investigated in other studies. The non-mineral component is isotopically very similar to Torque Trim, a drilling material added to the well prior to the discovery of the black material. The drilling engineers were convinced that fluids from the formation could not have leaked inside the drillpipe prior to the discovery. The analysis, therefore, suggests that the black material is a product of the Torque Trim, added in concentrated form with caustic soda, which was hydrolized down-hole, forming glycerol and sodium salts of fatty acids, and precipitating as a solid mass similar to soap. The interpretation explains the available data satisfactorily though it does not preclude other explanations.

  4. Synthesis and Optical Properties of Excited-State Intramolecular Proton Transfer Active π-Conjugated Benzimidazole Compounds: Influence of Structural Rigidification by Ring Fusion.

    Science.gov (United States)

    Takagi, Koji; Ito, Kaede; Yamada, Yoshihiro; Nakashima, Takuya; Fukuda, Ryoichi; Ehara, Masahiro; Masu, Hyuma

    2017-12-01

    Two excited-state intramolecular proton transfer (ESIPT) active benzimidazole derivatives (1 and 2) were synthesized by acid-catalyzed intramolecular cyclization. The steady-state fluorescence spectrum in THF revealed that ring-fused derivative 1 exhibits a dual emission, namely, the major emission was from the K* (keto) form (ESIPT emission) at 515 nm with a large Stokes shift of 11 100 cm-1 and the minor emission was from the E* (enol) form at below 400 nm. In contrast, the normal emission from the E* form was dominant and the fluorescence quantum yield was very low (Φ ∼ 0.002) for nonfused derivative 2. The time-resolved fluorescence spectroscopy of 1 suggested that ESIPT effectively occurs due to the restricted conformational transition to the S1-TICT state, and the averaged radiative and nonradiative decay rate constants were estimated as ⟨kf⟩ = 0.15 ns-1 and ⟨knr⟩ = 0.60 ns-1, respectively. The fluorescence emission of 1 was influenced by the measurement conditions, such as solvent polarity and basicity, as well as the presence of Lewis base. The ESIPT process and solvatochromic behavior were nicely reproduced by the DFT/TDDFT calculation using the PCM model. In the single-crystal fluorescent spectra, the ESIPT emissions were exclusively observed for both fused and nonfused compounds as a result of hydrogen-bonding interactions.

  5. Mutational analyses on X-linked adrenoleukodystrophy reveal a novel cryptic splicing and three missense mutations in the ABCD1 gene.

    Science.gov (United States)

    Hung, Kun-Long; Wang, Jinn-Shyan; Keng, Wee Teik; Chen, Hui-Ju; Liang, Jao-Shwann; Ngu, Lock Hock; Lu, Jyh-Feng

    2013-09-01

    X-linked adrenoleukodystrophy is caused by a defective peroxisomal membrane transporter, ABCD1, responsible for transporting very-long-chain fatty acid substrate into peroxisomes for degradation. The main biochemical defect, which is also one of the major diagnostic hallmarks, of X-linked adrenoleukodystrophy is the accumulation of saturated very-long-chain fatty acids in all tissues and body fluids. Direct and reverse-transcribed polymerase chain reactions followed by DNA sequencing-based mutational analyses were performed on one Taiwanese and three Malaysian X-linked adrenoleukodystrophy families. A novel splicing donor site mutation (c.1272+1g>a) was identified in a Taiwanese X-linked adrenoleukodystrophy patient, resulting in a deletion of 121 bp and a premature stop codon (p.Val425fs*92) in messenger-RNA transcript. This deletion is caused by the activation of a cryptic splicing donor site in exon 4 of the ABCD1 gene, which is consistent with the prediction by several online algorithms. In addition, three previously described missense mutations (c.965T>C, c.1978C>T, and c.2006A>G), leading to aberrant ABCD1 of p.Leu322Pro, p.Arg660Trp, and p.His669Arg, were also identified in Malaysian probands. This is the first report to unveil unequivocally that cryptic splicing-induced aberrant messenger-RNA carrying an internal frameshift deletion results from an intronic mutation in the ABCD1 gene. Furthermore, a polymorphism in intron 9 (c.1992-32c/t; refSNP: rs4898368) of the ABCD1 gene was commonly observed in both Taiwanese and Malaysian populations. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Preoperative Prediction of Type 2 Diabetes Remission After Gastric Bypass Surgery: a Comparison of DiaRem Scores and ABCD Scores.

    Science.gov (United States)

    Lee, Wei-Jei; Chong, Keong; Chen, Shu-Chun; Zachariah, James; Ser, Kong-Han; Lee, Yi-Chih; Chen, Jung-Chien

    2016-10-01

    Gastric bypass surgery has been well accepted as a novel treatment modality for type 2 diabetes mellitus (T2DM) in obese patients. Some scoring systems have been proposed for the selection of T2DM patients who are eligible for gastric bypass surgery. This study compares two scoring systems with regard to remission of T2DM after gastric bypass surgery. This retrospective cohort study included 245 patients (150 females and 95 males) who had undergone gastric bypass surgery for the treatment of T2DM with 1 year follow-up. We examined the predictive power of complete remission of two scoring systems, the DiaRem score, and the ABCD score. The DiaRem score includes the factors of age, HbA1c, medication, and insulin usage. The ABCD score includes the factors of age, BMI, C-peptide level, and duration of T2DM. The rate of remission of T2DM after gastric bypass surgery was evaluated using both scoring systems. At 1 year after surgery, the percent weight loss was 26.5 % and the mean BMI decreased from 35.7 to 26.2 kg/m(2). The mean HbA1c decreased from 8.8 to 6.2 %. A significant number of patients showed improvement in glycemic control, including 130 (53.1 %) patients with complete remission (HbA1c ABCD score predicted the success of the gastric bypass surgery, but the ABCD score was better at differentiating patients with poorer score (27.9 vs. 9.1 %, p ABCD score is better at predicting T2DM remission at 1 year after gastric bypass surgery than the DiaRem score.

  7. Computers in nonassociative rings and algebras

    CERN Document Server

    Beck, Robert E

    1977-01-01

    Computers in Nonassociative Rings and Algebras provides information pertinent to the computational aspects of nonassociative rings and algebras. This book describes the algorithmic approaches for solving problems using a computer.Organized into 10 chapters, this book begins with an overview of the concept of a symmetrized power of a group representation. This text then presents data structures and other computational methods that may be useful in the field of computational algebra. Other chapters consider several mathematical ideas, including identity processing in nonassociative algebras, str

  8. Ring closure in actin polymers

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Supurna, E-mail: supurna@rri.res.in [Raman Research Institute, Bangalore 560080 (India); Chattopadhyay, Sebanti [Doon University, Dehradun 248001 (India)

    2017-03-18

    We present an analysis for the ring closure probability of semiflexible polymers within the pure bend Worm Like Chain (WLC) model. The ring closure probability predicted from our analysis can be tested against fluorescent actin cyclization experiments. We also discuss the effect of ring closure on bend angle fluctuations in actin polymers. - Highlights: • Ring closure of biopolymers. • Worm like chain model. • Predictions for experiments.

  9. O-Ring-Testing Fixture

    Science.gov (United States)

    Turner, James E.; Mccluney, D. Scott

    1990-01-01

    Fixture used to evalute properties of O-rings of various materials. Hydraulic actuator positions plug in housing, creating controlled, variable gap in O-ring glands formed by grooves in plug and by inner wall of housing. Creates controlled axial and radial gaps between sealing surfaces around ring so effectiveness of material in maintaining seal determined under dynamic conditions.

  10. Clean elements in abelian rings

    Indian Academy of Sciences (India)

    equivalent to being clean for an abelian ring is 'topologically boolean'. In line with [1] we say that a ring R (not necessarily commutative) is right (resp. left) topologically boolean, or a right (resp. left) tb-ring for short, if for every pair of distinct maximal right (resp. left) ideals of R there is an idempotent in exactly one of them.

  11. Ring closure in actin polymers

    OpenAIRE

    Sinha, Supurna; Chattopadhyay, Sebanti

    2017-01-01

    We present an analysis for the ring closure probability of semiflexible polymers within the pure bend Worm Like Chain (WLC) model. The ring closure probability predicted from our analysis can be tested against fluorescent actin cyclization experiments.We also discuss the effect of ring closure on bend angle fluctuations in actin polymers.

  12. Mac-2 binding protein is a cell-adhesive protein of the extracellular matrix which self-assembles into ring-like structures and binds beta1 integrins, collagens and fibronectin

    DEFF Research Database (Denmark)

    Sasaki, T; Brakebusch, C; Engel, J

    1998-01-01

    Human Mac-2 binding protein (M2BP) was prepared in recombinant form from the culture medium of 293 kidney cells and consisted of a 92 kDa subunit. The protein was obtained in a native state as indicated by CD spectroscopy, demonstrating alpha-helical and beta-type structure, and by protease...... resistance and immunological analysis. It was highly modified by N- and O-glycosylation but not by glycosaminoglycans. Ultracentrifugation showed non-covalent association into oligomers with molar masses of 1000-1500 kDa. Electron microscopy showed ring-like shapes with diameters of 30-40 nm. M2BP bound...... in the extracellular matrix of several mouse tissues....

  13. Instructions for the use of the CIVM-Jet 4C finite-strain computer code to calculate the transient structural responses of partial and/or complete arbitrarily-curved rings subjected to fragment impact

    Science.gov (United States)

    Rodal, J. J. A.; French, S. E.; Witmer, E. A.; Stagliano, T. R.

    1979-01-01

    The CIVM-JET 4C computer program for the 'finite strain' analysis of 2 d transient structural responses of complete or partial rings and beams subjected to fragment impact stored on tape as a series of individual files. Which subroutines are found in these files are described in detail. All references to the CIVM-JET 4C program are made assuming that the user has a copy of NASA CR-134907 (ASRL TR 154-9) which serves as a user's guide to (1) the CIVM-JET 4B computer code and (2) the CIVM-JET 4C computer code 'with the use of the modified input instructions' attached hereto.

  14. Saturn Ring Observer

    Science.gov (United States)

    Spilker, T. R.

    2001-01-01

    Answering fundamental questions about ring particle characteristics, and individual and group behavior, appears to require close-proximity (a few km) observations. Saturn's magnificent example of a ring system offers a full range of particle sizes, densities, and behaviors for study, so it is a natural choice for such detailed investigation. Missions implementing these observations require post-approach Delta(V) of approximately 10 km/s or more, so past mission concepts called upon Nuclear Electric Propulsion. The concept described here reduces the propulsive Delta(V) requirement to as little as 3.5 km/s, difficult but not impossible for high-performance chemical propulsion systems. Additional information is contained in the original extended abstract.

  15. Satellite Rings Movie

    Science.gov (United States)

    2000-01-01

    This brief movie clip (of which the release image is a still frame), taken by NASA's Cassini spacecraft as it approached Jupiter, shows the motions, over a 16 hour-period, of two satellites embedded in Jupiter's ring. The moon Adrastea is the fainter of the two, and Metis the brighter. Images such as these will be used to refine the orbits of the two bodies.The movie was made from images taken during a 40-hour sequence of the Jovian ring on December 11, 2000.Cassini is a cooperative mission of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages Cassini for NASA's Office of Space Science, Washington, D.C.

  16. Eelgrass fairy rings

    DEFF Research Database (Denmark)

    Borum, Jens; Raun, Ane-Marie Løvendahl; Hasler-Sheetal, Harald

    2014-01-01

    Distinct ‘fairy rings’ consisting of narrow fringes of eelgrass (Zostera marina l.) expand radially over a bottom of chalk plates outside the calcium carbon- ate cliffs of the island of Møn, Denmark. We conducted a survey to evaluate possible explanations for the formation of the rings and, more...... sulfide accumulating in the sediment due to low iron availability in the carbonate-rich environment....

  17. Mechanical evaluation of aluminum alloy ring fixator.

    Science.gov (United States)

    Tosborvorn, Somboon; Cheechareon, Sukrom; Ruttanuchun, Kittiput; Sirivedin, Suparerk; Rhienumporn, Chaitawat

    2006-11-01

    To test the homemade ring fixator as a tool for correction of bony deformity. The authors developed an aluminum alloy ring fixator and tested it to find out the accuracy of manufacturing and strength of the ring systems under axial load with the Roundness Testing Machine and Lloyd Universal Testing Machine. The mean diameter of the twenty five-drill holes was 6.5843872 +/- 0.0521594 mm (mean +/- SD). Distance between particular drill holes, which reflected the precision of drilling, had a high accuracy with standard deviation from 0.1138 to 0.1870 mm. The roundness of the rings was 0.2421376 +/- 0.12437977 mm (mean +/- SD). The system structure had minimal permanent deformity at breaking point, mean yield strength of the system was 4786.9 +/- 14.353 N (mean +/- SD). This was caused by the failure of the wire. Mean stiffness of the system was 127 N./mm. The aluminum alloy ring fixator was strong enough and well tolerated for clinical usage

  18. Minimizing guard ring dead space in silicon detectors with an n-type guard ring at the edge of the detector

    Energy Technology Data Exchange (ETDEWEB)

    Palviainen, Tanja [Lappeenranta University of Technology, P.O. Box 20, FIN-53851 Lappeenranta (Finland)]. E-mail: tanja.palviainen@lut.fi; Tuuva, Tuure [Lappeenranta University of Technology, P.O. Box 20, FIN-53851 Lappeenranta (Finland); Leinonen, Kari [Lappeenranta University of Technology, P.O. Box 20, FIN-53851 Lappeenranta (Finland)

    2007-04-01

    Detectors with n-type silicon with an n{sup +}-type guard ring were investigated. In the present work, a new p{sup +}/n/n{sup +} detector structure with an n{sup +} guard ring is described. The guard ring is placed at the edge of the detector. The detector depletion region extends also sideways, allowing for signal collection very close to the n-guard ring. In this kind of detector structure, the dead space of the detector is minimized to be only below the guard ring. This is proved by simulations done using Silvaco/ATLAS software.

  19. High-resolution imaging of Saturn’s main rings during the Cassini Ring-Grazing Orbits and Grand Finale

    Science.gov (United States)

    Tiscareno, Matthew S.; Cassini Imaging Team

    2017-10-01

    Cassini is ending its spectacular 13-year mission at Saturn with a two-part farewell, during which it has obtained the sharpest and highest-fidelity images ever taken of Saturn’s rings. From December 2016 to April 2017, the spacecraft executed 20 near-polar orbits that passed just outside the outer edge of the main rings; these “Ring-Grazing Orbits” provided the mission’s best viewing of the A and F rings and the outer B ring. From April to September 2017, the spacecraft is executing 22 near-polar orbits that pass between the innermost D ring and the planet’s clouds; this “Grand Finale” provides the mission’s best viewing of the C and D rings and the inner B ring. 1) Clumpy BeltsClumpy structure called “straw” was previously observed in parts of the main rings [Porco et al. 2005, Science]. New images show this structure with greater clarity. More surprisingly, new images reveal strong radial variations in the degree and character of clumpiness, which are probably an index for particle properties and interactions. Belts with different clumpiness characteristics are often adjacent to each other and not easily correlated with other ring characteristics. 2) PropellersA “propeller” is a local disturbance in the ring created by an embedded moon [Tiscareno et al. 2006, Nature; 2010, ApJL]. Cassini has observed two classes of propellers: small propellers that swarm in the “Propeller Belts” of the mid-A ring, and “Giant Propellers” whose individual orbits can be tracked in the outer A ring. Both are shown in unprecedented detail in new images. Targeted flybys of Giant Propellers were executed on both the lit and unlit sides of the ring, yielding enhanced ability to convert brightness to optical depth and surface density. 3) Impact Ejecta CloudsBeing a large and delicate system, Saturn’s rings function as a detector of their planetary environment. Cassini images of impact ejecta clouds in the rings previously constrained the population of

  20. Preliminary Results from the Cassini RADAR Ring Observations

    Science.gov (United States)

    West, Richard D.; Janssen, Michael A.; Zhang, Zhimeng; Cuzzi, Jeffrey N.; Anderson, Yanhua; Hamilton, Gary; Elachi, Charles; Cassini RADAR Science Team

    2017-10-01

    In its last year of operation, the Cassini spacecraft executed a series of short highly inclined orbits that brought it close to Saturn’s rings. The Cassini RADAR instrument collected active and passive data of the rings in five separate observations. These observations provided a unique opportunity to obtain backscatter measurements and relatively high-resolution brightness temperature measurements from the rings. Such measurements were never before possible from the spacecraft or the Earth due to high range. Preliminary examination of the active data shows major ring structural features such as the Cassini Division, the Encke Gap, and the Keeler Gap. This presentation will show preliminary processing results from the radar rings scans and discuss the calibration and processing issues. These ring scan measurements provide a 1-D profile of backscatter obtained at 2.2 cm wavelength that complements similar passive profiles obtained at optical, infrared, and microwave wavelengths. Such measurements can further constrain and inform models of the ring particle composition and structure, and the local vertical structure of the rings. This work is supported by the NASA Cassini Program at JPL - CalTech.

  1. O-Ring-Testing Fixture

    Science.gov (United States)

    Turner, James E.; Mccluney, D. Scott

    1991-01-01

    Fixture tests O-rings for sealing ability under dynamic conditions after extended periods of compression. Hydraulic cylinder moves plug in housing. Taper of 15 degrees on plug and cavity of housing ensures that gap created between O-ring under test and wall of cavity. Secondary O-rings above and below test ring maintain pressure applied to test ring. Evaluates effects of variety of parameters, including temperature, pressure, rate of pressurization, rate and magnitude of radial gap movement, and pretest compression time.

  2. An evolving view of Saturn’s dynamic rings

    Science.gov (United States)

    Cuzzi, J.N.; Burns, J.A.; Charnoz, S.; Clark, Roger N.; Colwell, J.E.; Dones, L.; Esposito, L.W.; Filacchione, G.; French, R.G.; Hedman, M.M.; Kempf, S.; Marouf, E.A.; Murray, C.D.; Nicholson, P.D.; Porco, C.C.; Schmidt, J.; Showalter, M.R.; Spilker, L.J.; Spitale, J.; Srama, R.; Srem evi, M.; Tiscareno, M.S.; Weiss, J.

    2010-01-01

    We review our understanding of Saturn’s rings after nearly 6 years of observations by the Cassini spacecraft. Saturn’s rings are composed mostly of water ice but also contain an undetermined reddish contaminant. The rings exhibit a range of structure across many spatial scales; some of this involves the interplay of the fluid nature and the self-gravity of innumerable orbiting centimeter- to meter-sized particles, and the effects of several peripheral and embedded moonlets, but much remains unexplained. A few aspects of ring structure change on time scales as short as days. It remains unclear whether the vigorous evolutionary processes to which the rings are subject imply a much younger age than that of the solar system. Processes on view at Saturn have parallels in circumstellar disks.

  3. Mass of Saturn's A ring

    Science.gov (United States)

    Horn, L. J.; Russell, C. T.

    1993-01-01

    The mass of Saturn's A ring is reestimated using the behavior of spiral density waves embedded in the ring. The Voyager photopolarimeter (PPS) observed the star delta-Scorpii as it was occulted by Saturn's rings during the Voyager 2 flyby of Saturn in 1981 producing a radial profile of the rings. We examined forty spiral density waves in the Voyager PPS data of the A ring including 10 weaker waves that have not been previously analyzed by means of an autoregressive power spectral technique called Burg. The strengths of this new method for ring studies are that weaker, less extended waves are easily detected and characterized. This method is also the first one which does not require precise knowledge of the resonance location and phase of the wave in order to calculate the surface mass density. Uncertainties of up to 3 km are present in the currently available radial scales for Saturn's rings.

  4. The Wigner distribution function of a Lorentz-Gauss vortex beam passing through a paraxial ABCD optical system

    Science.gov (United States)

    Zhou, Yimin; Zhou, Guoquan; Dai, Chaoqing; Ru, Guoyun

    2015-03-01

    Based on the Collins integral formula and the Hermite-Gaussian expansion of a Lorentz function, an analytical expression for the Wigner distribution function (WDF) of a Lorentz-Gauss vortex beam passing through a paraxial ABCD optical system is derived. The WDF properties of a Lorentz-Gauss vortex beam propagating in free space are also demonstrated. During propagation, the WDF pattern shrinks in the direction of the spatial frequency variables and elongates in the direction of the transverse spatial coordinates. With given the transverse spatial coordinates or the spatial frequency variables, the evolvement of the WDF of a Lorentz-Gauss vortex beam during propagation is examined in detail. To show the WDF application, the second-order moments of the WDF for a Lorentz-Gauss vortex beam in free space are also presented. This research exhibits the propagation properties of a Lorentz-Gauss vortex beam from the phase space.

  5. Short-Term Prognosis of Transient Ischemic Attack and Predictive Value of the ABCD(2) Score in Hong Kong Chinese.

    Science.gov (United States)

    Chiu, Lai Hong Simon; Yau, Wah Hon; Leung, Ling Pong; Pang, Peter; Tsui, Chee Tat; Wan, Kuang An; Au, Thomas Tak-Shun; Fong, Wing Chi; Chung, Shun Hang Joseph

    2014-01-01

    Literature on prognosis of transient ischemic attack (TIA) in Chinese is scarce. The short-term prognosis of TIA and the predictive value of the ABCD(2) score in Hong Kong Chinese patients attending the emergency department (ED) were studied to provide reference for TIA patient management in our ED. A cohort of TIA patients admitted through the ED to 13 acute public hospitals in 2006 was recruited through the centralized electronic database by the Hong Kong Hospital Authority (HA). All inpatients were e-coded by the HA according to the International Classification of Diseases, Ninth Revision (ICD9). Electronic records and hard copies were studied up to 90 days after a TIA. The stroke risk of a separate TIA cohort diagnosed by the ED was compared. In the 1,000 recruited patients, the stroke risk after a TIA at days 2, 7, 30, and 90 was 0.2, 1.4, 2.9, and 4.4%, respectively. Antiplatelet agents were prescribed in 89%, warfarin in 6.9%, statin in 28.6%, antihypertensives in 39.3%, and antidiabetics in 11.9% of patients after hospitalization. Before the index TIA, the prescribed medications were 27.6, 3.7, 11.3, 27.1, and 9.7%, respectively. The accuracy of the ABCD(2) score in predicting stroke risk was 0.607 at 7 days, 0.607 at 30 days, and 0.574 at 90 days. At 30 days, the p for trend across ABCD(2) score levels was 0.038 (OR for every score point = 1.36, p = 0.040). Diabetes mellitus, previous stroke and carotid bruit were associated with stroke within 90 days (p = 0.038, 0.045, 0.030, respectively). A total of 45.4% of CTs of the brain showed lacunar infarcts or small vessel disease. There was an increased stroke risk at 90 days in patients with old or new infarcts on CT or MRI. Patients with carotid stenosis ≥70% had an increased stroke risk within 30 (OR = 6.335, p = 0.013) and 90 days (OR = 3.623, p = 0.050). Stroke risks at days 2, 7, 30, and 90 in the 289 TIA patients diagnosed by the ED were 0.35, 2.4, 5.2, and 6.2%, respectively. The short-term stroke

  6. Studies on polynuclear furoquinones. Part 1: Synthesis of tri- and tetra-cyclic furoquinones simulating BCD/ABCD ring system of furoquinone diterpenoids

    Directory of Open Access Journals (Sweden)

    Faruk H. Shaik

    2009-09-01

    Full Text Available Synthesis of phenanthro[1,2-b]furan-10,11-dione, the core nucleus present in Tanshinone-I is described in 8–10 steps starting from 2-bromo-3,4-dihydro-1-naphthaldehyde. The bromoaldehyde was converted to methyl 2-(2-bromo-1-naphthylacetate or 2-(2-bromo-1-naphthylacetonitrile following the protocol of functional group transformations. Subsequent Suzuki coupling of this ester/nitrile derivative with furan-2-boronic acid produced [2-(2-furyl-1-naphthyl]acetic ester/nitrile which on hydrolysis furnished the corresponding acid derivative. Cyclization of the acid followed by oxidation of the phenol, with Fremy’s salt, produced the tetra-cyclic furoquinone, phenanthro[1,2-b]furan-10,11-dione. This method has also been extended for the synthesis of the tricyclic furoquinone, naphtho[1,2-b]furan-4,5-dione.

  7. The effects of forming parameters on conical ring rolling process.

    Science.gov (United States)

    Meng, Wen; Zhao, Guoqun; Guan, Yanjin

    2014-01-01

    The plastic penetration condition and biting-in condition of a radial conical ring rolling process with a closed die structure on the top and bottom of driven roll, simplified as RCRRCDS, were established. The reasonable value range of mandrel feed rate in rolling process was deduced. A coupled thermomechanical 3D FE model of RCRRCDS process was established. The changing laws of equivalent plastic strain (PEEQ) and temperature distributions with rolling time were investigated. The effects of ring's outer radius growth rate and rolls sizes on the uniformities of PEEQ and temperature distributions, average rolling force, and average rolling moment were studied. The results indicate that the PEEQ at the inner layer and outer layer of rolled ring are larger than that at the middle layer of ring; the temperatures at the "obtuse angle zone" of ring's cross-section are higher than those at "acute angle zone"; the temperature at the central part of ring is higher than that at the middle part of ring's outer surfaces. As the ring's outer radius growth rate increases at its reasonable value ranges, the uniformities of PEEQ and temperature distributions increase. Finally, the optimal values of the ring's outer radius growth rate and rolls sizes were obtained.

  8. The contraceptive vaginal ring, NuvaRing(®), a decade after its introduction.

    Science.gov (United States)

    Roumen, Frans J M E; Mishell, Daniel R

    2012-12-01

    To review the clinical experience with the contraceptive vaginal ring (CVR, NuvaRing(®)) since its introduction over ten years ago. The literature was searched on efficacy, cycle control, safety, user preference and satisfaction of the CVR in comparison with combined oral contraceptives (COCs) and the patch, with special attention to recent developments. The ring has the same working mechanism and contraindications as COCs. Serum levels of steroids are steadier, whereas oestrogenic exposure is lower. Contraceptive efficacy is similar, as are metabolic changes. Cycle control is better, and compliance and continuation rates are equal or higher. Oestrogen-related adverse symptoms appear to be fewer, but reports on the incidence of venous thrombosis are conflicting. Expulsion of the ring is reported by 4% to 20% of women. Local adverse events are the main reason for discontinuation. Acceptability is as high as with COCs and, after structured counselling, the ring is preferred by many women to the pill or the patch. Efficacy of the CVR, and the metabolic changes and adverse events it elicits, are generally comparable to those of COCs, yet oestrogenic exposure is lower and cycle control superior. After counselling, the ring is preferred to the pill by many women.

  9. The specific effect of gallic acid on Escherichia coli biofilm formation by regulating pgaABCD genes expression.

    Science.gov (United States)

    Kang, Jiamu; Li, Qianqian; Liu, Liu; Jin, Wenyuan; Wang, Jingfan; Sun, Yuyang

    2018-02-01

    Escherichia coli (E. coli) is associated with an array of health-threatening contaminations, some of which are related to biofilm states. The pgaABCD-encoded poly-beta-1,6-N-acetyl-D-glucosamine (PGA) polymer plays an important role in biofilm formation. This study was conducted to determine the inhibitory effect of gallic acid (GA) against E. coli biofilm formation. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values of GA against planktonic E. coli were 0.5 and 4 mg/mL, and minimal biofilm inhibitory concentration and minimal biofilm eradication concentration values of GA against E. coli in biofilms were 2 and 8 mg/mL, respectively. Quantitative crystal violet staining of biofilms and ESEM images clearly indicate that GA effectively, dose-dependently inhibited biofilm formation. CFU counting and confocal laser scanning microscopy measurements showed that GA significantly reduced viable bacteria in the biofilm. The contents of polysaccharide slime, protein, and DNA in the E. coli biofilm also decreased. qRT-PCR data showed that at the sub-MIC level of GA (0.25 mg/mL) and expression of pgaABC genes was downregulated, while pgaD gene expression was upregulated. The sub-MBC level of GA (2 mg/mL) significantly suppressed the pgaABCD genes. Our results altogether demonstrate that GA inhibited viable bacteria and E. coli biofilm formation, marking a novel approach to the prevention and treatment of biofilm-related infections in the food industry.

  10. Expression Analyses of ABCDE Model Genes and Changes in Levels of Endogenous Hormones in Chinese Cabbage Exhibiting Petal-Loss

    Directory of Open Access Journals (Sweden)

    Chuan MENG

    2017-07-01

    Full Text Available Abnormal formation of floral organs affects plant reproduction and can directly interfere with the progress of breeding programs. Using PCR amplification, ABCDE model genes BraAP2, BraAP3, BraPI, BraAG, BraSHP, and BraSEP were isolated from Chinese cabbage (Brassica rapa L. ssp. pekinensis. We examined six development stages of floral buds collected from Chinese cabbage and compared between a line demonstrating normal flowering (A-8 and two mutated lines that exhibited plants having petal-loss (A-16 and A-17. The expression of ABCDE model genes has been analyzed by qRT-PCR. Compared with flower buds of petal-loss plants and normal plants, the expression of A-class gene BraAP2 was significantly decreased during the first to fourth stages, C-class gene BraAG expression was significantly decreased during the first to fifth stages, and D-class gene BraSHP expression was significantly decreased during the first to third stages. Furthermore, B-class gene BraAP3 and BraPI and E-class gene BraSEP expressions were significantly decreased during all six stages of petal-loss plants compared with normal plants. Enzyme-linked immunosorbent assays detected nine endogenous phytohormones during all stages examined here. Except for the second-stage and third-stage buds, levels of the auxin IAA and cytokinin dhZR were always higher in the petal-loss plants than the normal plants at corresponding time points. Meanwhile, concentrations of GA1+3 at the first, fourth, and fifth stages were higher in the petal-loss plants than in the normal plants. Our results provide a theoretical basis for future exploration of the molecular mechanism that determines petal loss and the effects that hormones have on such development in Chinese cabbage plants.

  11. Pre-pregnancy weight status, early pregnancy lipid profile and blood pressure course during pregnancy: The ABCD study.

    Science.gov (United States)

    Oostvogels, Adriëtte J J M; Busschers, Wim B; Spierings, Eline J M; Roseboom, Tessa J; Gademan, Maaike G J; Vrijkotte, Tanja G M

    2017-01-01

    Although pre-pregnancy weight status and early pregnancy lipid profile are known to influence blood pressure course during pregnancy, little is known about how these two factors interact. The association between pre-pregnancy weight status and blood pressure course during pregnancy was assessed in the prospective ABCD study and the role (independent/mediating/moderating) of early pregnancy lipid profile in this association was determined. We included 2500 normal weight (ABCD-study with available measurements of non-fasting early pregnancy lipids [median (IQR): 13 (12-14) weeks of gestation] and blood pressure during pregnancy [mean (SD) = 10 (2.3)]. Lipids (triglycerides, total cholesterol, apolipoprotein A1, apolipoprotein B and free fatty acids) were divided into tertiles. Multilevel piecewise linear spline models were used to describe the course of systolic and diastolic blood pressure (SBP/DBP) in four time periods during gestation for overweight and normal weight women. Both SBP (5.3 mmHg) and DBP (3.9 mmHg) were higher in overweight compared to normal weight women and this difference remained the same over all four time periods. The difference in SBP and DBP was not mediated or moderated by the lipid profile. Lipid profile had an independent positive effect on both SBP (range 1.3-2.2 mmHg) and DBP (0.8-1.1 mmHg), but did not change blood pressure course. Both pre-pregnancy weight status and early pregnancy lipid profile independently increase blood pressure during pregnancy. Improving pre-pregnancy weight status and early pregnancy lipid profile might result in a healthier blood pressure course during pregnancy.

  12. Effect of Lorenzo's Oil on Hepatic Gene Expression and the Serum Fatty Acid Level in abcd1-Deficient Mice.

    Science.gov (United States)

    Morita, Masashi; Honda, Ayako; Kobayashi, Akira; Watanabe, Yuichi; Watanabe, Shiro; Kawaguchi, Kosuke; Takashima, Shigeo; Shimozawa, Nobuyuki; Imanaka, Tsuneo

    2017-05-31

    Lorenzo's oil is known to decrease the saturated very long chain fatty acid (VLCFA) level in the plasma and skin fibroblasts of X-linked adrenoleukodystrophy (ALD) patients. However, the involvement of Lorenzo's oil in in vivo fatty acid metabolism has not been well elucidated. To investigate the effect of Lorenzo's oil on fatty acid metabolism, we analyzed the hepatic gene expression together with the serum fatty acid level in Lorenzo's oil-treated wild-type and abcd1-deficient mice. The change in the serum fatty acid level in Lorenzo's oil-treated abcd1-defcient mice was quite similar to that in the plasma fatty acid level in ALD patients supplemented with Lorenzo's oil. In addition, we found that the hepatic gene expression of two peroxisomal enzymes, Dbp and Scp2, and three microsomal enzymes, Elovl1, 2, and 3, were significantly stimulated by Lorenzo's oil. Our findings indicate that Lorenzo's oil activates hepatic peroxisomal fatty acid β-oxidation at the transcriptional level. In contrast, the transcriptional stimulation of Elovl1, 2, and 3 by Lorenzo's oil does not cause changes in the serum fatty acid level. It seems likely that the inhibition of these elongation activities by Lorenzo's oil results in a decrease in saturated VLCFA. Thus, these results not only contribute to a clarification of the mechanism by which the saturated VLCFA level is reduced in the serum of ALD patients by Lorenzo's oil-treatment, but also suggest the development of a new therapeutic approach to peroxisomal β-oxidation enzyme deficiency, especially mild phenotype of DBP deficiency.

  13. Astrocytes and mitochondria from adrenoleukodystrophy protein (ABCD1)-deficient mice reveal that the adrenoleukodystrophy-associated very long-chain fatty acids target several cellular energy-dependent functions.

    Science.gov (United States)

    Kruska, Nicol; Schönfeld, Peter; Pujol, Aurora; Reiser, Georg

    2015-05-01

    X-linked adrenoleukodystrophy (X-ALD) is a severe neurodegenerative disorder resulting from defective ABCD1 transport protein. ABCD1 mediates peroxisomal uptake of free very-long-chain fatty acids (VLCFA) as well as their CoA-esters. Consequently, VLCFA accumulate in patients' plasma and tissues, which is considered as pathogenic X-ALD triggering factor. Clinical symptoms are mostly manifested in neural tissues and adrenal gland. Here, we investigate astrocytes from wild-type control and a genetic X-ALD mouse model (Abcd1-knockout), exposed to supraphysiological VLCFA (C22:0, C24:0 and C26:0) concentrations. They exhibit multiple impairments of energy metabolism. Furthermore, brain mitochondria from Abcd1(-/-) mice and wild-type control respond similarly to VLCFA with increased ROS generation, impaired oxidative ATP synthesis and diminished Ca(2+) uptake capacity, suggesting that a defective ABCD1 exerts no adaptive pressure on mitochondria. In contrast, astrocytes from Abcd1(-/-) mice respond more sensitively to VLCFA than wild-type control astrocytes. Moreover, long-term application of VLCFA induces high ROS generation, and strong in situ depolarization of mitochondria, and, in Abcd1(-/-) astrocytes, severely diminishes the capability to revert oxidized pyridine nucleotides to NAD(P)H. In addition, observed differences in responses of mitochondria and astrocytes to the hydrocarbon chain length of VLCFA suggest that detrimental VLCFA activities in astrocytes involve defective cellular functions other than mitochondria. In summary, we clearly demonstrate that VLCFA increase the vulnerability of Abcd1(-/-) astrocytes. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Uranus - The planet, rings and satellites

    Science.gov (United States)

    Miner, Ellis D.

    The present overview of available data regarding Uranus and its planetary structures encompasses ground- and space-based observations of the planet with specific attention given to the interpretation of Voyager 2 data. A brief examination of historical observations is given which includes its discovery, position determination, and the related discoveries of Uranus' five large satellites and rings. The observational data preceding the Voyager 2 mission are reviewed in terms of the planetary interior, atmosphere, and magnetosphere. The Voyager 2 mission is given detailed treatment with descriptions of NASA's development and deployment of the spacecraft as well as detailed data from the Uranus encounter. Reference is given to structure and composition of Uranus' atmosphere, valid models of the interior, and wave-particle interactions in the magnetosphere. The structures of the rings and satellites are examined with reference to specific observational requirements from future missions.

  15. Unraveling the strands of Saturn's F ring

    Science.gov (United States)

    Murray, C.D.; Gordon, M.K.; Giuliatti, Winter S.M.

    1997-01-01

    Several high-resolution Voyager 2 images of Saturn's F ring show that it is composed of at least four separate, non-intersecting strands extending ~45?? in longitude. Voyager 1 images show that the two brightest strands appear to intersect, giving rise to a "braided" morphology. From a study of all available Voyager images the detectable radial structure is cataloged and reviewed. Previous indications that there is fine material interior to the orbit of the F ring are confirmed. Evidence is presented that a model of four strands with comparable eccentricities and nearly aligned perichrones is consistent with all the Voyager observations. The observed perichrone offset of the two brightest strands suggests a minimum radial separation of ~20 km, which implies intersection of these strands when their finite radial widths are taken into account. The longitude range of such an intersection includes that observed in the Voyager 1 "braid" images. The proximity of these two strands at some longitudes may account for the apparent differences in the ring between the Voyager encounters, as well as provide a source for the short-lived features detected in the Hubble Space Telescope images of the F ring. There is no evidence that the locations of the individual strands are determined by resonant perturbations with known satellites. It is proposed that the radial structure is formed by the localized action of small satellites orbiting within the strand region. ?? 1997 Academic Press.

  16. Viscosity of ring polymer melts

    KAUST Repository

    Pasquino, Rossana

    2013-10-15

    We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

  17. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Stroppel, Catharina

    2014-01-01

    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from Korff, C., Stroppel, C.: The sl(ˆn)k-WZNW fusion ring: a combinato-rial construction and a realis......We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from Korff, C., Stroppel, C.: The sl(ˆn)k-WZNW fusion ring: a combinato-rial construction...... and a realisation as quotient of quantum cohomology. Adv. Math. 225(1), 200–268, (2010) and give a similar description of the sp2n-fusion ring in terms of non-commutative symmetric functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also...... compute the fusion rings for type G2....

  18. Natural occurrence, biological activities and synthesis of eight-, nine-, and eleven-membered ring lactones

    Directory of Open Access Journals (Sweden)

    Helena M. C. Ferraz

    2008-01-01

    Full Text Available The natural occurrence, biological activities and synthetic approaches to natural eight-, nine-, and eleven-membered lactones is reviewed. These medium ring lactones are grouped according to ring size, and their syntheses are discussed. The structures of some natural products early identified as medium-ring lactones were revised after total synthesis.

  19. Mass transfer during ice particle collisions in planetary rings

    Science.gov (United States)

    Mcdonald, J. S. B.; Hatzes, A.; Bridges, F.; Lin, D. N. C.

    1989-01-01

    Experimental results are presented from laboratory environment simulations of the ice particle collisional properties defining the structure and dynamical evolution of planetary rings. It is inferred from these data that there is a dependence of the interacting volume on the impact velocity. Although the volume fraction exchanged during a collision is small, the net amount of material transferred can be substantially smaller. Attention is given to the implications of these determinations for planetary ring structure and evolution.

  20. Compositional Evolution of Saturn's Rings Due to Meteoroid Bombardment

    Science.gov (United States)

    Cuzzi, J.; Estrada, P.; Young, Richard E. (Technical Monitor)

    1997-01-01

    In this paper we address the question of compositional evolution in planetary ring systems subsequent to meteoroid bombardment. The huge surface area to mass ratio of planetary rings ensures that this is an important process, even with current uncertainties on the meteoroid flux. We develop a new model which includes both direct deposition of extrinsic meteoritic "pollutants", and ballistic transport of the increasingly polluted ring material as impact ejecta. Our study includes detailed radiative transfer modeling of ring particle spectral reflectivities based on refractive indices of realistic constituents. Voyager data have shown that the lower optical depth regions in Saturn's rings (the C ring and Cassini Division) have darker and less red particles than the optically thicken A and B rings. These coupled structural-compositional groupings have never been explained; we present and explore the hypothesis that global scale color and compositional differences in the main rings of Saturn arise naturally from extrinsic meteoroid bombardment of a ring system which was initially composed primarily, but not entirely, of water ice. We find that the regional color and albedo differences can be understood if all ring material was initially identical (primarily water ice, based on other data, but colored by tiny amounts of intrinsic reddish, plausibly organic, absorber) and then evolved entirely by addition and mixing of extrinsic, nearly neutrally colored. plausibly carbonaceous material. We further demonstrate that the detailed radial profile of color across the abrupt B ring - C ring boundary can.constrain key unknown parameters in the model. Using new alternates of parameter values, we estimate the duration of the exposure to extrinsic meteoroid flux of this part of the rings, at least, to be on the order of 10(exp 8) years. This conclusion is easily extended by inference to the Cassini Division and its surroundings as well. This geologically young "age" is compatible

  1. Ring Image Analyzer

    Science.gov (United States)

    Strekalov, Dmitry V.

    2012-01-01

    Ring Image Analyzer software analyzes images to recognize elliptical patterns. It determines the ellipse parameters (axes ratio, centroid coordinate, tilt angle). The program attempts to recognize elliptical fringes (e.g., Newton Rings) on a photograph and determine their centroid position, the short-to-long-axis ratio, and the angle of rotation of the long axis relative to the horizontal direction on the photograph. These capabilities are important in interferometric imaging and control of surfaces. In particular, this program has been developed and applied for determining the rim shape of precision-machined optical whispering gallery mode resonators. The program relies on a unique image recognition algorithm aimed at recognizing elliptical shapes, but can be easily adapted to other geometric shapes. It is robust against non-elliptical details of the image and against noise. Interferometric analysis of precision-machined surfaces remains an important technological instrument in hardware development and quality analysis. This software automates and increases the accuracy of this technique. The software has been developed for the needs of an R&TD-funded project and has become an important asset for the future research proposal to NASA as well as other agencies.

  2. Moduli space of filtered λ-ringstructures over a filtered ring

    Directory of Open Access Journals (Sweden)

    Donald Yau

    2004-01-01

    Full Text Available Motivated in part by recent works on the genus of classifying spaces of compact Lie groups, here we study the set of filtered λ-ring structures over a filtered ring from a purely algebraic point of view. From a global perspective, we first show that this set has a canonical topology compatible with the filtration on the given filtered ring. For power series rings R[[x

  3. Ring current and radiation belts

    Science.gov (United States)

    Williams, D. J.

    1987-01-01

    Studies performed during 1983-1986 on the ring current, the injection boundary model, and the radiation belts are discussed. The results of these studies yielded the first observations on the composition and charge state of the ring current throughout the ring-current energy range, and strong observational support for an injection-boundary model accounting for the origins of radiation-belt particles, the ring current, and substorm particles observed at R less than about 7 earth radii. In addition, the results have demonstrated that the detection of energetic neutral atoms generated by charge-exchange interactions between the ring current and the hydrogen geocorona can provide global images of the earth's ring current and its spatial and temporal evolution.

  4. Self-assembly of InAs ring complexes on InP substrates by droplet epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Noda, T.; Mano, T.; Jo, M.; Kawazu, T. [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Sakaki, H. [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Toyota Technological Institute, 2-12-1 Hisakata, Tempaku-ku, Nagoya 468-8511 (Japan)

    2012-09-15

    We report the self-assembly of InAs ring complexes on InP (100) substrates by droplet epitaxy. Single-ring, ring-disk complex, and concentric double-ring structures were formed by controlling the As beam flux and substrate temperature. A clear photoluminescence signal was detected in a sample where InAs rings were embedded in InGaAs.

  5. RE{sub 3}Au{sub 5}Zn (RE = Y, Sm, Gd-Ho). A new structure type with five- and six-membered rings as building units in a gold network

    Energy Technology Data Exchange (ETDEWEB)

    Gerke, Birgit; Poettgen, Rainer [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie and NRW Graduate School of Chemistry

    2016-08-01

    RE{sub 3}Au{sub 5}Zn (RE = Y, Sm, Gd-Ho) intermetallic compounds were synthesized by melting the elements in sealed tantalum tubes. They exhibit a new structure type which was studied by X-ray diffraction on powders and refined from single crystal diffraction data: Cmcm, a = 736.9(2), b = 1489.4(2), c = 1330.4(3) pm, wR2 = 0.0371, 1184 F{sup 2} values and 55 variables for Y{sub 3}Au{sub 4.92}Zn{sub 1.08} and a = 739.0(1), b = 1495.8(2), c = 1339.2(2) pm, wR2 = 0.0325, 1410 F{sup 2} values and 54 variables for Tb{sub 3}Au{sub 5}Zn. The network consists of five- and six-membered gold rings in puckered conformations. Atoms of the rare earth elements are placed within the cavities of this network where every third cavity is filled by a Zn{sub 2} dumbbell. The structure is discussed in detail and compared with the gold substructure of Hf{sub 7}Au{sub 10}.

  6. Biscembranoids formed from an α,β-unsaturated γ-lactone ring as a dienophile: structure revision and establishment of their absolute configurations using theoretical calculations of electronic circular dichroism spectra.

    Science.gov (United States)

    Jia, Rui; Kurtán, Tibor; Mándi, Attila; Yan, Xiao-Hong; Zhang, Wen; Guo, Yue-Wei

    2013-04-05

    Four new biscembranoids, bislatumlides C-F (1-4), were isolated from the Hainan soft coral Sarcophyton latum . Their structures were elucidated by detailed analysis of spectroscopic data and by comparison with reported data of related derivatives, leading to the structure revision of co-occurring bislatumlides A (5) and B (6) at the C-21 configuration. The absolute configurations of bislatumlides C and E (1 and 3) were determined by TDDFT calculations of their solution ECD spectra, allowing the configurational assignment of the related bislatumlides D and F (2 and 4) and A and B (5 and 6) as well. Bislatumlides A-F (1-6) represent the only biscembranoids formed by the undescribed coupling pattern of Diels-Alder cycloaddition between the Δ(1(2)) double bond involving an α,β-unsaturated γ-lactone ring as a dienophile group and a trisubstituted conjugated Δ(21(34))/Δ(35(36))-butadiene moiety. An endo-cycloaddition gave 1, 2, 5, and 6, whereas an exo-cycloaddition produced 3 and 4. This is the first report of exo-addition dicembranoids from marine sources and from nature. Bislatumlides C and E (1, 3) could be used as ECD reference compounds in the determination of absolute configuration for related derivatives.

  7. Filtration on a Ring Make a Quasi Valuation or Valuation Ring

    Directory of Open Access Journals (Sweden)

    Mohammad Hassan Anjom SHoa

    2014-06-01

    Full Text Available In this paper we show that if R is a filtered ring then we can define a quasi valuation ring. And there exists a valuation ring if R is some kind of filtered ring. Then we prove some properties and relations between filtered ring and quasi valuation ring and valuation ring.

  8. Saturn's Rings and Associated Ring Plasma Cavity: Evidence for Slow Ring Erosion

    Science.gov (United States)

    Farrell, W. M.; Kurth, W. S.; Gurnett, D. A.; Persoon, A. M.; MacDowall, R. J.

    2017-01-01

    We re-examine the radio and plasma wave observations obtained during the Cassini Saturn orbit insertion period, as the spacecraft flew over the northern ring surface into a radial distance of 1.3 Rs (over the C-ring). Voyager era studies suggest the rings are a source of micro-meteoroid generated plasma and dust, with theorized peak impact-created plasma outflows over the densest portion of the rings (central B-ring). In sharp contrast, the Cassini Radio and Plasma Wave System (RPWS) observations identify the presence of a ring-plasma cavity located in the central portion of the B-ring, with little evidence of impact-related plasma. While previous Voyager era studies have predicted unstable ion orbits over the C- ring, leading to field-aligned plasma transport to Saturns ionosphere, the Cassini RPWS observations do not reveal evidence for such instability-created plasma fountains. Given the passive ring loss processes observed by Cassini, we find that the ring lifetimes should extend >10(exp 9) years, and that there is limited evidence for prompt destruction (loss in <100 Myrs).

  9. Saturn's rings and associated ring plasma cavity: Evidence for slow ring erosion

    Science.gov (United States)

    Farrell, W. M.; Kurth, W. S.; Gurnett, D. A.; Persoon, A. M.; MacDowall, R. J.

    2017-08-01

    We re-examine the radio and plasma wave observations obtained during the Cassini Saturn orbit insertion period, as the spacecraft flew over the northern ring surface into a radial distance of 1.3 Rs (over the C-ring). Voyager era studies suggest the rings are a source of micro-meteoroid generated plasma and dust, with theorized peak impact-created plasma outflows over the densest portion of the rings (central B-ring). In sharp contrast, the Cassini Radio and Plasma Wave System (RPWS) observations identify the presence of a ring-plasma cavity located in the central portion of the B-ring, with little evidence of impact-related plasma. While previous Voyager era studies have predicted unstable ion orbits over the C-ring, leading to field-aligned plasma transport to Saturn's ionosphere, the Cassini RPWS observations do not reveal evidence for such instability-created plasma 'fountains'. Given the passive ring loss processes observed by Cassini, we find that the ring lifetimes should extend >109 years, and that there is limited evidence for prompt destruction (loss in <100 Myrs).

  10. Remarks on modeling the flexible seal ring housing

    Science.gov (United States)

    Kundera, C.; Martsynkovskyy, V.; Zahorulko, A.

    2017-08-01

    When formulating models of dynamic face seals, two issues are of essential importance. The first concerns the determination of the forces formed in the medium film in the gap formed by the faces of two rings, while the second refers to the model of the flexible housing of one of the seal rings. The first issue includes the analysis of the medium flow through a narrow slit, taking thermal phenomena and deformations of slit-forming surfaces into account. The second issue concerns the modeling of properties of seal structural components, especially the modeling of elastic-damping properties of the flexible seal ring housing. This paper presents the results of simple relaxation tests of elastomeric rings and the procedure for analyzing these results and evaluating the elastic-damping properties of the rings tested. Finally, experimental results will be compared with theory.

  11. Superluminal and slow light in eye-like ring resonator

    Science.gov (United States)

    Zhang, Yundong; Ma, Kai; Wu, Yongfeng; Su, Huaiyin; Li, Hui; Yuan, Ping

    2017-02-01

    We investigate the phase and group delay in eye-like ring resonator with the effect of different coupling coefficients and attenuation factors. The eye-like structure is composed of two bus waveguides coupling with the outer ring and the two rings coupling together which have the same perimeters. The eye-like ring resonator has two outputs which have different transmission characteristics. In this paper, we measure the group delay of the two outputs through changing the coupling coefficients and the attenuation factors of the inner and the outer ring. The result shows that the two outputs have reverse group delay (superluminal and slow light) which will have potential use in slow light fiber, optical buffers and optical switches.

  12. Cassini discovers a kinematic spiral ring around Saturn.

    Science.gov (United States)

    Charnoz, S; Porco, C C; Déau, E; Brahic, A; Spitale, J N; Bacques, G; Baillie, K

    2005-11-25

    Since the time of the Voyager flybys of Saturn in 1980-1981, Saturn's eccentric F ring has been known to be accompanied on either side by faint strands of material. New Cassini observations show that these strands, initially interpreted as concentric ring segments, are in fact connected and form a single one-arm trailing spiral winding at least three times around Saturn. The spiral rotates around Saturn with the orbital motion of its constituent particles. This structure is likely the result of differential orbital motion stretching an initial cloud of particles scattered from the dense core of the F ring. Different scenarios of formation, implying ringlet-satellite interactions, are explored. A recently discovered moon candidate, S/2004 S6, is on an orbit that crosses the F-ring core at the intersection of the spiral with the ring, which suggests a dynamical connection between S/2004 S6 and the spiral.

  13. n-X-Coherent Rings

    OpenAIRE

    Bennis, Driss

    2010-01-01

    This paper unifies several generalizations of coherent rings in one notion. Namely, we introduce $n$-$\\mathscr{X}$-coherent rings, where $\\mathscr{X}$ is a class of modules and $n$ is a positive integer, as those rings for which the subclass $\\mathscr{X}_n$ of $n$-presented modules of $\\mathscr{X}$ is not empty, and every module in $\\mathscr{X}_n$ is $n+1$-presented. Then, for each particular class $\\mathscr{X}$ of modules, we find correspondent relative coherent rings. Our main aim is to sho...

  14. Integrated Ring Resonators The Compendium

    CERN Document Server

    Rabus, Dominik G

    2007-01-01

    The optical filter, which has emerged in the last few years in integrated optics, is resonator based. Ring-resonator filters do not require facets or gratings for optical feedback and are thus particularly suited for monolithic integration with other components. Ring resonators find applications not only in optical networks, but also as sensors. The required passband shape of ring resonator-filters can be custom designed by the use of configurations of various ring coupled resonators. This book describes the current state-of-the-art on these devices with respect to design, fabrication and application.

  15. ABCDE, but in that order? A cross-sectional survey of Michigan intensive care unit sedation, delirium, and early mobility practices.

    Science.gov (United States)

    Miller, Melissa A; Govindan, Sushant; Watson, Sam R; Hyzy, Robert C; Iwashyna, Theodore J

    2015-07-01

    A bundled approach to intensive care unit (ICU) care known as "Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility" (ABCDE) has been proposed, with evidence supporting individual interventions as well as the bundle as a whole. Few data exist on the bundle's implementation and efficacy in community practice. To evaluate self-reported rates of implementation of ABCDE components and their association with outcomes in a state-wide quality improvement collaborative. A written survey was administered to representatives attending the 2012 annual meeting of the Michigan Health and Hospital Association's Keystone ICU collaborative. Respondents reported on their practices regarding spontaneous awakening trials, delirium assessments, and early mobility. There were 212 respondents, a 76% response rate. Wide variation in focus was noted across the assessed components of ABCDE. Only 12% reported having implemented routine spontaneous awakening trials and delirium assessments as well as early mobility, 36% reported not having early mobility as an active goal in their units (nonmovers), and 52% reported attempts at early mobility without both routine sedation interruption and delirium screening implementation. In adjusted models, those who implemented exercise with sedation interruption and delirium screening were 3.5 (95% confidence interval, 1.4-8.6) times more likely to achieve higher levels of exercise in ventilated patients than those who implemented exercise without both sedation interruption and delirium screening. There is incomplete penetrance of aspects of ABCDE across ICUs in this highly motivated statewide quality improvement collaborative. Yet, implementation of exercise in the context of both sedation interruption and delirium screening was associated with improved self-reported mobility outcomes. Effective knowledge translation and implementation strategies may offer substantial benefits to ICU patients.

  16. Differing clinical presentations of two unrelated cases of X-linked adrenoleukodystrophy with identical mutation Y296C in the ABCD1 gene.

    Science.gov (United States)

    Sutovský, Stanislav; Kolníková, Miriam; Petrovic, Róbert; Kollár, Branislav; Siarnik, Pavel; Chandoga, Ján; Fischerová, Mária; Turcáni, Peter

    2014-01-01

    X-linked adrenoleukodystrophy is a genetically determined disorder that causes varying degrees of malfunction of the adrenal cortex and central nervous system. Our aim was to investigate the occurrence of known, or new, mutations in the ABCD1 gene in two unrelated patients with clinical suspicion of the adrenoleukodystrophy. Two unrelated patients - the first with behavioral changes, the second with progressive cognitive deficit - underwent a clinical and genetic examination in order to establish a diagnosis and discover a possible mutation. In the first patient, a 47 year old man, the clinical examination showed dementia of the frontal type and spastic quadriparesis. The patient also suffered from adrenal insufficiency for 6 years. An MRI showed confluent hyperintensive lesions in FLAIR images in the frontal lobe of both hemispheres. The second patient, a 16 year old boy, suffered also from Addison's disease since the age of 9, and developed cognitive deficit in the course of one year. The MRI showed posterior atrophy and hyperintensive lesions in parietal and occipital lobes in T2WI. In both cases, genetic analyses showed a missense mutation at the codon 887 (A>G) in exon 1 of the ABCD1 gene, predicting the substitution Y296C in the ALD protein. We detected the same mutation of the ABCD1 gene in two unrelated patients with ALD. In the first case there was frontal lobe involvement, in the second case parieto-occipital involvement. Both pathologic involvement and clinical presentation differed in two cases of the same mutation.

  17. Genomic profiling identifies novel mutations and SNPs in ABCD1 gene: a molecular, biochemical and clinical analysis of X-ALD cases in India.

    Directory of Open Access Journals (Sweden)

    Neeraj Kumar

    Full Text Available X-linked adrenoleukodystrophy (X-ALD affects the nervous system white matter and adrenal cortex secondary to mutations in the ABCD1 gene that encode the peroxisomal membrane protein. We conducted a genomic and protein expression study of susceptibility gene with its clinical and biochemical analysis. To the best of our knowledge this is the first preliminary comprehensive study in Indian population that identified novel mutations and SNPs in a relatively large group. We screened 17 Indian indigenous X-linked adrenoleukodystrophy cases and 70 controls for mutations and SNPs in the exonic regions (including flanking regions of ABCD1 gene by direct sequencing with ABI automated sequencer along with Western blot analysis of its endogenous protein, ALDP, levels in peripheral blood mononuclear cells. Single germ line mutation was identified in each index case in ABCD1 gene. We detected 4 novel mutations (2 missense and 2 deletion/insertion and 3 novel single nucleotide polymorphisms. We observed a variable protein expression in different patients. These findings were further extended to biochemical and clinical observations as it occurs with great clinical expression variability. This is the first major study in this population that presents a different molecular genetic spectrum as compared to Caucasian population due to geographical distributions of ethnicity of patients. It enhances our knowledge of the causative mutations of X-ALD that grants holistic base to develop effective medicine against X-ALD.

  18. RING E3 ligases

    DEFF Research Database (Denmark)

    Cho, Seok Keun; Ryu, Moon Young; Kim, Jong Hum

    2017-01-01

    Plants are constantly exposed to a variety of abiotic stresses, such as drought, heat, cold, flood, and salinity. To survive under such unfavorable conditions, plants have evolutionarily developed their own resistant-mechanisms. For several decades, many studies have clarified specific stress...... response pathways of plants through various molecular and genetic studies. In particular, it was recently discovered that ubiquitin proteasome system (UPS), a regulatory mechanism for protein turn over, is greatly involved in the stress responsive pathways. In the UPS, many E3 ligases play key roles...... in recognizing and tethering poly-ubiquitins on target proteins for subsequent degradation by the 26S proteasome. Here we discuss the roles of RING ligases that have been defined in related to abiotic stress responses in plants....

  19. Maximally differential ideals in regular local rings

    Indian Academy of Sciences (India)

    Introduction. Let (A, m) be a Noetherian local ring and let I be an ideal in A. Assume that I is maxi- mally differential under a set of derivations of A. Then A/I contains a field k. If k is of characteristic p > 0 then the structure of A/I is given by Harper's theorem [4] (see [7] for a proof). Assume now that A/I contains a field of ...

  20. The eRHIC Ring-Ring Collider Design

    CERN Document Server

    Wang, Fuhua; Beebe-Wang, Joanne; Deshpande, Abhay A; Farkhondeh, Manouchehr; Franklin, Wilbur; Graves, William; Litvinenko, Vladimir N; MacKay, William W; Milner, Richard; Montag, Christoph; Ozaki, Satoshi; Parker, Brett; Peggs, Steve; Ptitsyn, Vadim; Roser, Thomas; Tepikian, Steven; Trbojevic, Dejan; Tschalär, C; Wang, Dong; Zolfaghari, Abbasali; Zwart, Townsend; van der Laan, Jan

    2005-01-01

    The eRHIC ring-ring collider is the main design option of the future lepton-ion collider at Brookhaven National Laboratory. We report the revisions of the ring-ring collider design features to the baseline design presented in the eRHIC Zeroth Design Report (ZDR). These revisions have been made during the past year. They include changes of the interaction region which are required from the modifications in the design of the main detector. They also include changes in the lepton storage ring for high current operations as a result of better understandings of beam-beam interaction effects. The updated collider luminosity and beam parameters also take into account a more accurate picture of current and future operational aspects of RHIC.

  1. Rheology modification with ring polymers

    Science.gov (United States)

    Vlassopoulos, Dimitris

    It is now established that experimental unconcatenated ring polymers can be purified effectively by means of fractionation at the critical condition. For molecular weights well above the entanglement threshold, purified rings relax stress via power-law (with an exponent of about -0.4), sharply departing from their linear counterparts. Experimental results are in harmony with modeling predictions and simulations. Here, we present results from recent interdisciplinary efforts and discuss two challenges: (i) the nonlinear shear rheology of purified ring melts is also very different from that of unlinked chains. Whereas the latter exhibit features that can be explained, to a first approach, in the framework in the tube model, the former behave akin to unentangled chains with finite extensibility and exhibit much small deformation at steady state. (ii) blends of rings and linear polymers exhibit unique features in different regimes: The addition of minute amounts of linear chains drastically affects ring dynamics. This relates to ring purity and the ability of unlinked linear chains to thread rings. With the help of simulations, it is possible to rationalize the observed surprisingly slow viscoelastic relaxation, which is attributed to ring-linear and ring-ring penetrations. On the other hand, adding small amounts of rings to linear polymers of different molecular weights influences their linear and nonlinear rheology in an unprecedented way. The blend viscosity exceeds that of the slower component (linear) in this non-interacting mixture, and its dependencies on composition and molecular weight ratio are examined, whereas the role of molecular architecture is also addressed. Consequently, closing the ends of a linear chain can serve as a powerful means for molecular manipulation of its rheology. This presentation reflects collaborative efforts with S. Costanzo, Z-C. Yan, R. Pasquino, M. Kaliva, S. Kamble, Y. Jeong, P. Lutz, J. Allgaier, T. Chang, D. Talikis, V

  2. The structural analysis and modelling of ring substituent effect for the ortho-derivatives of 1-hydroxynaphthalene-2-carboxanilides and 2-hydroxynaphthalene-1-carboxanilides

    Science.gov (United States)

    Škorňa, Peter; Michalík, Martin; Lukeš, Vladimír; Klein, Erik

    2017-09-01

    The quantum chemical DFT study of 1-hydroxynaphthalene-2-carboxanilide (A-H) and 2-hydroxynaphthalene-1-carboxanilide (B-H) and their selected ortho-derivatives (A-R, B-R) is presented. The structural analysis showed that the energetically preferred conformation is stabilized via the intramolecular hydrogen bonds occurring between the Cdbnd O⋯H-O1 of A-H molecule and Cdbnd O⋯H-O2 groups of B-H molecule. The A-R derivatives are practically planar, while the B-R derivatives are slightly distorted due to the spatial repulsion of hydrogen atoms. The conformation analysis of molecules with deprotonated hydroxyl group supports the concept of existence of two conformer types with respect to the sbnd NHsbnd COsbnd bridge orientation. Stabilization of the naphtholate moiety by a hydrogen bond to the amide sbnd NHsbnd group may allow the compound to cross the membrane to the extracellular space. The ortho substitution effect on the selected calculated properties was analyzed and the theoretical data were correlated with the substituent constants. For the B-R derivatives, the antitubercular activity concentrations were correlated and predicted by the calculated quantities.

  3. Structure-guided lead optimization of triazolopyrimidine-ring substituents identifies potent Plasmodium falciparum dihydroorotate dehydrogenase inhibitors with clinical candidate potential.

    Science.gov (United States)

    Coteron, Jose M; Marco, María; Esquivias, Jorge; Deng, Xiaoyi; White, Karen L; White, John; Koltun, Maria; El Mazouni, Farah; Kokkonda, Sreekanth; Katneni, Kasiram; Bhamidipati, Ravi; Shackleford, David M; Angulo-Barturen, Iñigo; Ferrer, Santiago B; Jiménez-Díaz, María Belén; Gamo, Francisco-Javier; Goldsmith, Elizabeth J; Charman, William N; Bathurst, Ian; Floyd, David; Matthews, David; Burrows, Jeremy N; Rathod, Pradipsinh K; Charman, Susan A; Phillips, Margaret A

    2011-08-11

    Drug therapy is the mainstay of antimalarial therapy, yet current drugs are threatened by the development of resistance. In an effort to identify new potential antimalarials, we have undertaken a lead optimization program around our previously identified triazolopyrimidine-based series of Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) inhibitors. The X-ray structure of PfDHODH was used to inform the medicinal chemistry program allowing the identification of a potent and selective inhibitor (DSM265) that acts through DHODH inhibition to kill both sensitive and drug resistant strains of the parasite. This compound has similar potency to chloroquine in the humanized SCID mouse P. falciparum model, can be synthesized by a simple route, and rodent pharmacokinetic studies demonstrated it has excellent oral bioavailability, a long half-life and low clearance. These studies have identified the first candidate in the triazolopyrimidine series to meet previously established progression criteria for efficacy and ADME properties, justifying further development of this compound toward clinical candidate status.

  4. Structure-Guided Lead Optimization of Triazolopyrimidine-Ring Substituents Identifies Potent Plasmodium falciparum Dihydroorotate Dehydrogenase Inhibitors with Clinical Candidate Potential

    Energy Technology Data Exchange (ETDEWEB)

    Coteron, Jose M.; Marco, Maria; Esquivias, Jorge; Deng, Xiaoyi; White, Karen L.; White, John; Koltun, Maria; El Mazouni, Farah; Kokkonda, Sreekanth; Katneni, Kasiram; Bhamidipati, Ravi; Shackleford, David M.; Angulo-Barturen, Inigo; Ferrer, Santiago B.; Jimenez-Diaz, Maria Belen; Gamo, Francisco-Javier; Goldsmith, Elizabeth J.; Charman, William N.; Bathurst, Ian; Floyd, David; Matthews, David; Burrows, Jeremy N.; Rathod, Pradipsinh K.; Charman, Susan A.; Phillips, Margaret A. (UWASH); (MMV, Switzerland); (GSK); (Monash); (UW); (UTSMC)

    2012-02-27

    Drug therapy is the mainstay of antimalarial therapy, yet current drugs are threatened by the development of resistance. In an effort to identify new potential antimalarials, we have undertaken a lead optimization program around our previously identified triazolopyrimidine-based series of Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) inhibitors. The X-ray structure of PfDHODH was used to inform the medicinal chemistry program allowing the identification of a potent and selective inhibitor (DSM265) that acts through DHODH inhibition to kill both sensitive and drug resistant strains of the parasite. This compound has similar potency to chloroquine in the humanized SCID mouse P. falciparum model, can be synthesized by a simple route, and rodent pharmacokinetic studies demonstrated it has excellent oral bioavailability, a long half-life and low clearance. These studies have identified the first candidate in the triazolopyrimidine series to meet previously established progression criteria for efficacy and ADME properties, justifying further development of this compound toward clinical candidate status.

  5. Sensitivity enhanced fiber sensor based on a fiber ring microwave photonic filter with the Vernier effect.

    Science.gov (United States)

    Xu, Zuowei; Shu, Xuewen; Fu, Hongyan

    2017-09-04

    A temperature sensor employing the Vernier effect generated from a cascaded fiber rings based microwave photonic filter (MPF) is proposed and experimentally demonstrated. The structure of the fiber ring is used as a sensing element as well as the sampling and delaying component of the MPF in our proposed sensing scheme. The sensing characteristics of both single ring and cascaded fiber rings based sensors have been studied and compared. By employing two cascaded fiber rings of slightly different length, the Vernier effect can be generated in the frequency response of the MPF. The sensing interrogation of the cascaded fiber rings based sensor is conducted by detecting the frequency shift of the upper envelope of the measured frequency response curve. The experimental results show that the sensitivity of the cascaded fiber rings based sensor can be improved about 30 times compared with the single fiber ring based temperature sensor.

  6. Clean elements in abelian rings

    Indian Academy of Sciences (India)

    Let be a ring with identity. An element in is said to be clean if it is the sum of a unit and an idempotent. is said to be clean if all of its elements are clean. If every idempotent in is central, then is said to be abelian. In this paper we obtain some conditions equivalent to being clean in an abelian ring.

  7. Code–checkable group rings

    Directory of Open Access Journals (Sweden)

    Noha Abdelghany

    2017-01-01

    Full Text Available A code over a group ring is defined to be a submodule of that group ring. For a code $C$ over a group ring $RG$, $C$ is said to be checkable if there is $v\\in RG$ such that {$C=\\{x\\in RG: xv=0\\}$}. In \\cite{r2}, Jitman et al. introduced the notion of code-checkable group ring. We say that a group ring $RG$ is code-checkable if every ideal in $RG$ is a checkable code. In their paper, Jitman et al. gave a necessary and sufficient condition for the group ring $\\mathbb{F}G$, when $\\mathbb{F}$ is a finite field and $G$ is a finite abelian group, to be code-checkable. In this paper, we give some characterizations for code-checkable group rings for more general alphabet. For instance, a finite commutative group ring $RG$, with $R$ is semisimple, is code-checkable if and only if $G$ is $\\pi'$-by-cyclic $\\pi$; where $\\pi$ is the set of noninvertible primes in $R$. Also, under suitable conditions, $RG$ turns out to be code-checkable if and only if it is pseudo-morphic.

  8. Richard Schatzki: a familiar ring.

    Science.gov (United States)

    Patel, Birju; Han, Eugene; Swan, Kenneth

    2013-11-01

    The Schatzki ring was named for Richard Schatzki, a renowned radiologist who described the entity with his colleague, John E. Gary. The purpose of this article is to shed more light on a man who made such a significant contribution and to chronicle developments concerning this important radiologic finding. The Schatzki ring was described long ago, but its cause is poorly understood even today.

  9. Contraceptive vaginal rings: a review.

    Science.gov (United States)

    Brache, Vivian; Faundes, Anibal

    2010-11-01

    Development efforts on contraceptive vaginal rings were initiated over 40 years ago based on two principles: the capacity of the vaginal epithelium to absorb steroids and the capacity of elastomers to release these hormones at a nearly constant rate. Numerous models of contraceptive vaginal rings (CVRs) have been studied, but only two have reached the market: NuvaRing, a combined ring that releases etonogestrel (ENG) and ethinylestradiol (EE), and Progering, a progesterone-releasing ring for use in lactating women. The main advantages of CVRs are their effectiveness (similar to or slightly better than the pill), ease of use without the need of remembering a daily routine, user's ability to control initiation and discontinuation, nearly constant release rate allowing for lower doses, greater bioavailability and good cycle control with the combined ring. The main disadvantages are related to the mode of delivery; CVRs may cause vaginal discharge and complaints, ring expulsion is not uncommon, the ring may be felt during coitus and vaginal insertion may be unpleasant for some women. The studies reviewed in this article provide evidence that CVRs are safe, effective and highly acceptable to women. There is no doubt that CVRs offer a new, effective contraceptive option to women, expanding their available choices of hormonal contraception. Copyright © 2010 Elsevier Inc. All rights reserved.

  10. How Jupiter's Ring Was Discovered.

    Science.gov (United States)

    Elliot, James; Kerr, Richard

    1985-01-01

    "Rings" (by astronomer James Elliot and science writer Richard Kerr) is a nontechnical book about the discovery and exploration of ring systems from the time of Galileo to the era of the Voyager spacecraft. One of this book's chapters is presented. (JN)

  11. Constructions over localizations of rings

    Directory of Open Access Journals (Sweden)

    Alessandro Logar

    1987-11-01

    Full Text Available In this paper we construct a category of effective noetherian rings in which linear equations can be “solved”. This category is closed with respect to some important constructions like trascendental extensions, quotientations, finite products and localizations with respect to a large class of multiplicatively closed systems. Hence it gives a definition of “constructive” rings.

  12. DELPHI's Ring Imaging Cherenkov Chamber

    CERN Multimedia

    1989-01-01

    The hundreds of mirrors around this Ring Imaging Cherenkov Chamber reflect cones of light created by fast moving particles to a detector. The velocity of a particle can be measured by the size of the ring produced on the detector. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

  13. Volumetric velocity measurements of vortex rings from inclined exits

    Science.gov (United States)

    Troolin, Daniel R.; Longmire, Ellen K.

    2010-03-01

    Vortex rings were generated by driving pistons within circular cylinders of inner diameter D = 72.8 mm at a constant velocity U 0 over a distance L = D. The Reynolds number, U 0 L/(2ν), was 2500. The flow downstream of circular and inclined exits was examined using volumetric 3-component velocimetry (V3V). The circular exit yields a standard primary vortex ring that propagates downstream at a constant velocity and a lingering trailing ring of opposite sign associated with the stopping of the piston. By contrast, the inclined nozzle yields a much more complicated structure. The data suggest that a tilted primary vortex ring interacts with two trailing rings; one associated with the stopping of the piston, and the other associated with the asymmetry of the cylinder exit. The two trailing ring structures, which initially have circulation of opposite sign, intertwine and are distorted and drawn through the center of the primary ring. This behavior was observed for two inclination angles. Increased inclination was associated with stronger interactions between the primary and trailing vortices as well as earlier breakdown.

  14. Volumetric velocity measurements of vortex rings from inclined exits

    Energy Technology Data Exchange (ETDEWEB)

    Troolin, Daniel R. [TSI Incorporated, Fluid Mechanics Division, St. Paul, MN (United States); Longmire, Ellen K. [University of Minnesota, Department of Aerospace Engineering and Mechanics, Minneapolis, MN (United States)

    2010-03-15

    Vortex rings were generated by driving pistons within circular cylinders of inner diameter D=72.8 mm at a constant velocity U{sub 0} over a distance L=D. The Reynolds number, U{sub 0}L/(2{nu}), was 2500. The flow downstream of circular and inclined exits was examined using volumetric 3-component velocimetry (V3V). The circular exit yields a standard primary vortex ring that propagates downstream at a constant velocity and a lingering trailing ring of opposite sign associated with the stopping of the piston. By contrast, the inclined nozzle yields a much more complicated structure. The data suggest that a tilted primary vortex ring interacts with two trailing rings; one associated with the stopping of the piston, and the other associated with the asymmetry of the cylinder exit. The two trailing ring structures, which initially have circulation of opposite sign, intertwine and are distorted and drawn through the center of the primary ring. This behavior was observed for two inclination angles. Increased inclination was associated with stronger interactions between the primary and trailing vortices as well as earlier breakdown. (orig.)

  15. Caldera ring-fault intrusion through repeated sheet capture

    Science.gov (United States)

    Browning, J.; Gudmundsson, A.

    2014-12-01

    The subsurface structure of caldera-bounding ring faults remains a contentious issue, with geometries often inferred from numerical and analogue models as well as from geophysical studies. All of these inferred structures need to be compared with actual ring-faults so as to test the model implications. Here we present field observations of a deeply eroded and uniquely well exposed section of caldera ring fault in a Tertiary central volcano in south-western Iceland. The Hafnarfjall ring fault represents the outermost fault complex of an elliptical caldera with an original diameter of approximately 5 km. Vertical displacement is estimated to be > 200 m on the steeply inward-dipping ring fault. Several thin (software COMSOL, we offer a mechanical explanation for the deflection of inclined sheets into sub-vertical dikes at a mechanically stratified fault damage zone and core. A model is proposed whereby ring faults can act as a barrier for the propagation of inclined sheets away from a magma chamber within the caldera. Our findings provide an alternative mechanical explanation for magma channelling along caldera ring-faults, which is a process likely to be fundamental in controlling the location of post-caldera volcanism.

  16. Saturn Ring Seismology: Interpreting the Seismogram

    Science.gov (United States)

    Marley, Mark Scott

    2013-01-01

    Marley (1990) and Marley and Porco (1993) proposed that f-mode oscillations of Saturn could excite resonant density and bending waves in the inner C-ring. They hypothesized that certain wave features discovered by Rosen et al. (1991) that were not associated with known satellite resonances could be the result of such resonant interactions with the planetary oscillation modes. They also predicted that if this was the case the waves would be found to be density (and not bending) waves by Cassini and predicted the azimuthal wave number of the C-ring waves m. Employing Cassini VIMS stellar occultation data Hedman and Nicholson (2013) have now confirmed the predictions and demonstrated that at least some of the C-ring features identified by Rosen et al. are indeed likely caused by resonant oscillation modes of Saturn. Given this context we have taken a fresh look at the Saturn ring seismology. First we propose that an apparent bending wave denoted 'j' by Rosen may be a second order outer vertical resonance with the l=3, m=2 f-mode of Saturn and discuss the locations of other plausible second order resonances in the rings. Since only a handful of ring resonances have been identified, measuring even one or two additional planetary mode frequencies would substantially assist the process of inverting mode frequencies to constrain Saturn interior's structure. Using the available mode frequencies, modern inversion technique employed in stellar seismology, and a recent set of Saturn interior models we provide an initial estimation of what available mode frequencies are telling us about the interior structure of the planet. Since the f-modes are confined relatively closely to the planetary surface, most of the observed modes probe only the outermost layers of the planet that are already comparatively well understood. However the l = 2 mode does probe relatively deeply into the planet and we will discuss the potential the measurement of this mode frequency has for placing new

  17. The Search for Ringed Exoplanets

    Science.gov (United States)

    Kohler, Susanna

    2017-04-01

    Are planetary rings as common in our galaxy as they are in our solar system? A new study demonstrates how we might search for ringed exoplanets and then possibly finds one!Saturns Elsewhere?Artists illustration of the super ring system around exoplanet J1407b. This is the only exoplanet weve found with rings, but its not at all like Saturn. [Ron Miller]Our solar system is filled with moons and planetary rings, so it stands to reason that exoplanetary systems should exhibit the same features. But though weve been in the planet-hunting game for decades, weve only found one exoplanet thats surrounded by a ring system. Whats more, that system J1407b has enormous rings that are vastly different from the modest, Saturn-like rings that we might expect to be more commonplace.Have we not discovered ringed exoplanets just because theyre hard to identify? Or is it because theyre not out there? A team of scientists led by Masataka Aizawa (University of Tokyo) has set out to answer this question by conducting a systematic search for rings around long-period planet candidates.The transit light curve of KIC 10403228, shown with three models: the best-fitting planet-only model (blue) and the two best-fitting planet+ring models (green and red). [Aizawa et al. 2017]The Hunt BeginsWhy long-period planets? Rings are expected to be unstable as the planet gets closer to the central star. Whats more, the planet needs to be far enough away from the stars warmth for the icy rings to exist. The authors therefore select from the collection of candidate transiting planets 89 long-period candidates that might be able to host rings.Aizawa and collaborators then fit single-planet models (with no rings) to the light curves of these planets and search for anomalies curves that arent fit well by these standard models. Particularly suspicious characteristics include a long ingress/egress as the planet moves across the face of the star, and asymmetry of the transit shape.After applying a series of

  18. Ionization cooling ring for muons

    Directory of Open Access Journals (Sweden)

    R. Palmer

    2005-06-01

    Full Text Available Practical ionization cooling rings could lead to lower cost or improved performance in neutrino factory or muon collider designs. The ring modeled here uses realistic three-dimensional fields. The performance of the ring compares favorably with the linear cooling channel used in the second U.S. Neutrino Factory Study. The normalized 6D emittance of an ideal ring is decreased by a factor of approximately 240, compared with a factor of only 15 for the linear channel. We also examine such real-world effects as windows on the absorbers and rf cavities and leaving empty lattice cells for injection and extraction. For realistic conditions the ring decreases the normalized 6D emittance by a factor of 49.

  19. Tuning terahertz transitions in a double-gated quantum ring

    Science.gov (United States)

    Collier, T. P.; Saroka, V. A.; Portnoi, M. E.

    2017-12-01

    We theoretically investigate the optical functionality of a semiconducting quantum ring manipulated by two electrostatic lateral gates used to induce a double quantum well along the ring. The well parameters and corresponding interlevel spacings, which lie in the THz range, are highly sensitive to the gate voltages. Our analysis shows that selection rules for interlevel dipole transitions, caused by linearly polarized excitations, depend on the polarization vector angle with respect to the gates. In striking difference from the conventional symmetric double well potential, the ring geometry permits polarization-dependent transitions between the ground and second excited states, allowing the use of this structure in a three-level lasing scheme.

  20. Morphology of large impact craters and basins on Venus: Implications for ring formation

    Science.gov (United States)

    Alexopoulos, Jim S.; McKinnon, William B.

    1993-03-01

    A nearly complete examination of the Magellan radar data for the Venusian surface reveals 72 unequivocal peak-ring craters and 4 larger structures that we interpret to be multiringed. This report updates our earlier studies and that of the Magellan team. The general morphology of peak-ring craters, decreasing ring diameter ratio trends with increasing crater diameter, and the general size-morphology progression from complex central-peak crater to peak-ring crater on Venus and the terrestrial planets suggest similar processes of peak-ring formation. Observations are consistent with a model of dynamic collapse, downward and outward, of an unstable central peak to form a ring. We interpret the four larger ringed structures (Klenova, Lise Meitner, Mead, and Isabella) to be morphologically similar to the Orientale Basin on the Moon, and thus, true multiringed basins.

  1. Is the bell ringing?

    CERN Multimedia

    Francesco Poppi

    2010-01-01

    During the Nobel prize-winning UA1 experiment, scientists in the control room used to ring a bell if a particularly interesting event had occurred. Today, the “CMS Exotica hotline” routine produces a daily report that lists the exotic events that were recorded the day before.   Display of an event selected by the Exotica routine. Take just a very small fraction of the available data (max. 5%); define the events that you want to keep and set the parameters accordingly; run the Exotica routine and only look at the very few images that the system has selected for you. This is the recipe that a small team of CMS researchers has developed to identify the signals coming from possible new physics processes. “This approach does not replace the accurate data analysis on the whole set of data. However, it is a very fast and effective way to focus on just a few events that are potentially very interesting”, explains Maurizio Pierini (CERN), who developed the...

  2. Hybrid silicon ring lasers

    Science.gov (United States)

    Liang, Di; Fiorentino, Marco; Bowers, John E.; Beausoleil, Raymond G.

    2011-01-01

    Hybrid silicon platform provides a solution to integrate active components (lasers, amplifiers, photodetectors, etc.) with passive ones on the same silicon substrate, which can be used for building an optical interconnect system. Owing to the advantages in footprint, power consumption, and high-speed modulation, hybrid silicon microring lasers have been demonstrated as a potential candidate for on-chip silicon light source. In this paper we review the progress to improve the performance of recently demonstrated compact microring lasers with ring diameter of 50 μm. A simple approach to enhance optical mode and electron-hole recombination, which results in threshold reduction and efficiency improvement is developed. This is done by appropriately undercutting the multiple quantum well (MQW) region to force carriers to flow towards the outer edge of the microring for better gain/optical mode overlap. We observe a reduction of the threshold of over 20% and up to 80% output power enhancement. The model and the experimental results highlight the benefits, as well as the negative effects from excessive undercutting, including lower MQW confinement, higher modal loss and higher thermal impedance. A design rule for MQW undercutting is therefore provided. Application as on-chip optical interconnects is discussed from a system perspective.

  3. Algebra 1 groups, rings, fields and arithmetic

    CERN Document Server

    Lal, Ramji

    2017-01-01

    This is the first in a series of three volumes dealing with important topics in algebra. It offers an introduction to the foundations of mathematics together with the fundamental algebraic structures, namely groups, rings, fields, and arithmetic. Intended as a text for undergraduate and graduate students of mathematics, it discusses all major topics in algebra with numerous motivating illustrations and exercises to enable readers to acquire a good understanding of the basic algebraic structures, which they can then use to find the exact or the most realistic solutions to their problems.

  4. Ion Rings for Magnetic Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Greenly, John, B.

    2005-07-31

    This Final Technical Report presents the results of the program, Ion Rings for Magnetic Fusion, which was carried out under Department of Energy funding during the period August, 1993 to January, 2005. The central objective of the program was to study the properties of field-reversed configurations formed by ion rings. In order to reach this objective, our experimental program, called the Field-reversed Ion Ring Experiment, FIREX, undertook to develop an efficient, economical technology for the production of field-reversed ion rings. A field-reversed configuration (FRC) in which the azimuthal (field-reversing) current is carried by ions with gyro-radius comparable to the magnetic separatrix radius is called a field-reversed ion ring. A background plasma is required for charge neutralization of the ring, and this plasma will be confined within the ring's closed magnetic flux. Ion rings have long been of interest as the basis of compact magnetic fusion reactors, as the basis for a high-power accelerator for an inertial fusion driver, and for other applications of high power ion beams or plasmas of high energy density. Specifically, the FIREX program was intended to address the longstanding question of the contribution of large-orbit ions to the observed stability of experimental FRCs to the MHD tilt mode. Typical experimental FRCs with s {approx} 2-4, where s is the ratio of separatrix radius to ion gyro-radius, have been stable to tilting, but desired values for a fusion reactor, s > 20, should be unstable. The FIREX ring would consist of a plasma with large s for the background ions, but with s {approx} 1 for the ring ions. By varying the proportions of these two populations, the minimum proportion of large-orbit ions necessary for stability could be determined. The incorporation of large-orbit ions, perhaps by neutral-beam injection, into an FRC has been advanced for the purpose of stabilizing, heating, controlling angular momentum, and aiding the formation

  5. The Christiansen Effect in Saturn's narrow dusty rings and the spectral identification of clumps in the F ring

    Science.gov (United States)

    Hedman, M.M.; Nicholson, P.D.; Showalter, M.R.; Brown, R.H.; Buratti, B.J.; Clark, R.N.; Baines, K.; Sotin, Christophe

    2011-01-01

    Stellar occultations by Saturn's rings observed with the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft reveal that dusty features such as the F ring and the ringlets in the Encke and the Laplace Gaps have distinctive infrared transmission spectra. These spectra show a narrow optical depth minimum at wavelengths around 2.87??m. This minimum is likely due to the Christiansen Effect, a reduction in the extinction of small particles when their (complex) refractive index is close to that of the surrounding medium. Simple Mie-scattering models demonstrate that the strength of this opacity dip is sensitive to the size distribution of particles between 1 and 100??m across. Furthermore, the spatial resolution of the occultation data is sufficient to reveal variations in the transmission spectra within and among these rings. In both the Encke Gap ringlets and F ring, the opacity dip weakens with increasing local optical depth, which is consistent with the larger particles being concentrated near the cores of these rings. The Encke Gap ringlets also show systematically weaker opacity dips than the F ring and Laplace Gap ringlet, implying that the former has a smaller fraction of grains less than ~30??m across. However, the strength of the opacity dip varies most dramatically within the F ring; certain compact regions of enhanced optical depth lack an opacity dip and therefore appear to have a greatly reduced fraction of grains in the few-micron size range. Such spectrally-identifiable structures probably represent a subset of the compact optically-thick clumps observed by other Cassini instruments. These variations in the ring's particle size distribution can provide new insights into the processes of grain aggregation, disruption and transport within dusty rings. For example, the unusual spectral properties of the F-ring clumps could perhaps be ascribed to small grains adhering onto the surface of larger particles in regions of anomalously

  6. Socioeconomic inequalities in lipid and glucose metabolism in early childhood in a population-based cohort: the ABCD-Study

    Directory of Open Access Journals (Sweden)

    van den Berg Gerrit

    2012-08-01

    Full Text Available Abstract Background Socioeconomic inequalities in cardiovascular disease are pervasive, yet much remains to be understood about how they originate. The objective of this study was to explore the relations of socioeconomic status to lipid and glucose metabolism as indicators of cardiovascular health in 5–6 year olds. Additionally to explore the explanatory role of maternal factors, birth outcome, and child factors. Methods In 1308 5–6 year old ethnic Dutch children from the ABCD cohort study, lipids (cholesterol, LDL, HDL, triglycerides, glucose and C-peptide were measured after an overnight-fast. Results There were no differences in cholesterol, HDL, LDL, and triglycerides between socioeconomic groups, as indicated by maternal education and income adequacy. However, children of low educated mothers had on average a higher glucose (β = 0.15; 95% confidence interval (CI 0.03 – 0.27, logC-peptide (β = 0.07; 95% CI 0.04 – 0.09, and calculated insulin resistance (HOMA-IR (β = 0.15; 95% CI 0.08 – 0.22 compared to children of high educated mothers. Only childhood BMI partly explained these differences (models controlled for age, height, and sex. Conclusions The socioeconomic gradient in cardiovascular risk factors seems to emerge in early childhood. In absence of underlying mechanisms these empirical findings are relevant for public health care and further explanatory research.

  7. Frailty and geography: should these two factors be added to the ABCDE contemporary guide to diabetes therapy?

    Science.gov (United States)

    Maddaloni, Ernesto; D'Onofrio, Luca; Pozzilli, Paolo

    2016-02-01

    On the road towards personalized treatments for type 2 diabetes, we suggest here that two parameters could be added to the ABCDE algorithm, 'F' for frailty and 'G' for geography. Indeed, the progressive ageing of population is causing a simultaneous increase of frailty worldwide. The identification of the optimal therapeutic approach is often difficult in frail subjects because of the complexity of 'frailty syndrome'. Nevertheless, given the relevance of diabetes in the development and progression of frailty, a safe and effective cure of diabetes is extremely important to guarantee a good medical outcome. There are few data about diabetes treatment in this delicate category of patients, and the choice of the appropriate therapy mostly remains a challenge. Moreover, type 2 diabetes affects more than 382 million people of different countries, races and ethnicities. To face the lack of solid evidence-based medicine for the treatment of diabetes in different ethnic groups, it is extremely important to increase knowledge about the different pathophysiology of diabetes according to ethnicity. In this way, a tailored approach to treatment of various ethnic groups living in the same or different regions can eventually be developed. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Socioeconomic inequalities in lipid and glucose metabolism in early childhood in a population-based cohort: the ABCD-Study

    Science.gov (United States)

    2012-01-01

    Background Socioeconomic inequalities in cardiovascular disease are pervasive, yet much remains to be understood about how they originate. The objective of this study was to explore the relations of socioeconomic status to lipid and glucose metabolism as indicators of cardiovascular health in 5–6 year olds. Additionally to explore the explanatory role of maternal factors, birth outcome, and child factors. Methods In 1308 5–6 year old ethnic Dutch children from the ABCD cohort study, lipids (cholesterol, LDL, HDL, triglycerides), glucose and C-peptide were measured after an overnight-fast. Results There were no differences in cholesterol, HDL, LDL, and triglycerides between socioeconomic groups, as indicated by maternal education and income adequacy. However, children of low educated mothers had on average a higher glucose (β = 0.15; 95% confidence interval (CI) 0.03 – 0.27), logC-peptide (β = 0.07; 95% CI 0.04 – 0.09), and calculated insulin resistance (HOMA-IR) (β = 0.15; 95% CI 0.08 – 0.22) compared to children of high educated mothers. Only childhood BMI partly explained these differences (models controlled for age, height, and sex). Conclusions The socioeconomic gradient in cardiovascular risk factors seems to emerge in early childhood. In absence of underlying mechanisms these empirical findings are relevant for public health care and further explanatory research. PMID:22852830

  9. On the Green's function of the partially diffusion-controlled reversible ABCD reaction for radiation chemistry codes

    Energy Technology Data Exchange (ETDEWEB)

    Plante, Ianik, E-mail: ianik.plante-1@nasa.gov [Wyle Science, Technology & Engineering, 1290 Hercules, Houston, TX 77058 (United States); Devroye, Luc, E-mail: lucdevroye@gmail.com [School of Computer Science, McGill University, 3480 University Street, Montreal H3A 0E9 (Canada)

    2015-09-15

    Several computer codes simulating chemical reactions in particles systems are based on the Green's functions of the diffusion equation (GFDE). Indeed, many types of chemical systems have been simulated using the exact GFDE, which has also become the gold standard for validating other theoretical models. In this work, a simulation algorithm is presented to sample the interparticle distance for partially diffusion-controlled reversible ABCD reaction. This algorithm is considered exact for 2-particles systems, is faster than conventional look-up tables and uses only a few kilobytes of memory. The simulation results obtained with this method are compared with those obtained with the independent reaction times (IRT) method. This work is part of our effort in developing models to understand the role of chemical reactions in the radiation effects on cells and tissues and may eventually be included in event-based models of space radiation risks. However, as many reactions are of this type in biological systems, this algorithm might play a pivotal role in future simulation programs not only in radiation chemistry, but also in the simulation of biochemical networks in time and space as well.

  10. On the Green's function of the partially diffusion-controlled reversible ABCD reaction for radiation chemistry codes

    Science.gov (United States)

    Plante, Ianik; Devroye, Luc

    2015-09-01

    Several computer codes simulating chemical reactions in particles systems are based on the Green's functions of the diffusion equation (GFDE). Indeed, many types of chemical systems have been simulated using the exact GFDE, which has also become the gold standard for validating other theoretical models. In this work, a simulation algorithm is presented to sample the interparticle distance for partially diffusion-controlled reversible ABCD reaction. This algorithm is considered exact for 2-particles systems, is faster than conventional look-up tables and uses only a few kilobytes of memory. The simulation results obtained with this method are compared with those obtained with the independent reaction times (IRT) method. This work is part of our effort in developing models to understand the role of chemical reactions in the radiation effects on cells and tissues and may eventually be included in event-based models of space radiation risks. However, as many reactions are of this type in biological systems, this algorithm might play a pivotal role in future simulation programs not only in radiation chemistry, but also in the simulation of biochemical networks in time and space as well.

  11. Ring-Ringlet Interactions in Saturn's C Ring

    Science.gov (United States)

    Rappaport, N. J.

    1997-01-01

    The overall obejective of this work is to derive a theoretical model for the formation of gaps harboring isolated ringlets in order to explain the presence of such features in Saturn's C ring and Cassini division.

  12. Origin and Evolution of Saturn's Ring System

    OpenAIRE

    Charnoz, Sebastien; Dones, Luke; Esposito, Larry W.; Estrada, Paul R.; Hedman, Matthew M.

    2009-01-01

    The origin and long-term evolution of Saturn's rings is still an unsolved problem in modern planetary science. In this chapter we review the current state of our knowledge on this long-standing question for the main rings (A, Cassini Division, B, C), the F Ring, and the diffuse rings (E and G). During the Voyager era, models of evolutionary processes affecting the rings on long time scales (erosion, viscous spreading, accretion, ballistic transport, etc.) had suggested that Saturn's rings are...

  13. Soft Congruence Relations over Rings

    Directory of Open Access Journals (Sweden)

    Xiaolong Xin

    2014-01-01

    Full Text Available Molodtsov introduced the concept of soft sets, which can be seen as a new mathematical tool for dealing with uncertainty. In this paper, we initiate the study of soft congruence relations by using the soft set theory. The notions of soft quotient rings, generalized soft ideals and generalized soft quotient rings, are introduced, and several related properties are investigated. Also, we obtain a one-to-one correspondence between soft congruence relations and idealistic soft rings and a one-to-one correspondence between soft congruence relations and soft ideals. In particular, the first, second, and third soft isomorphism theorems are established, respectively.

  14. Codes over infinite family of rings : Equivalence and invariant ring

    Science.gov (United States)

    Irwansyah, Muchtadi-Alamsyah, Intan; Muchlis, Ahmad; Barra, Aleams; Suprijanto, Djoko

    2016-02-01

    In this paper, we study codes over the ring Bk=𝔽pr[v1,…,vk]/(vi2=vi,∀i =1 ,…,k ) . For instance, we focus on two topics, i.e. characterization of the equivalent condition between two codes over Bk using a Gray map into codes over finite field 𝔽pr, and finding generators for invariant ring of Hamming weight enumerator for Euclidean self-dual codes over Bk.

  15. First principles study of electronic structure for cubane-like and ring-shaped structures of M4O4, M4S4 clusters (M = Mn, Fe, Co, Ni, Cu

    Directory of Open Access Journals (Sweden)

    Soumendu Datta

    2015-11-01

    Full Text Available Spin-polarized DFT has been used to perform a comparative study of the geometric structures and electronic properties for isolated M4X4 nano clusters between their two stable isomers - a planar rhombus-like 2D structure and a cubane-like 3D structure with M = Mn, Fe, Co, Ni, Cu ; X = O, S. These two structural patterns of the M4X4 clusters are commonly found as building blocks in several poly-nuclear transition metal complexes in inorganic chemistry. The effects of the van der Waals corrections to the physical properties have been considered in the electronic structure calculations employing the empirical Grimme’s correction (DFT+D2. We report here an interesting trend in their relative structural stability - the isolated M4O4 clusters prefer to stabilize more in the planar structure, while the cubane-like 3D structure is more favorable for most of the isolated M4S4 clusters than their planar 2D counterparts. Our study reveals that this contrasting trend in the relative structural stability is expected to be driven by an interesting interplay between the s-d and p-d hybridization effects of the constituents’ valence electrons.

  16. The ring nerve of the box jellyfish Tripedalia cystophora.

    Science.gov (United States)

    Garm, A; Poussart, Y; Parkefelt, L; Ekström, P; Nilsson, D-E

    2007-07-01

    Box jellyfish have the most elaborate sensory system and behavioural repertoire of all cnidarians. Sensory input largely comes from 24 eyes situated on four club-shaped sensory structures, the rhopalia, and behaviour includes obstacle avoidance, light shaft attractance and mating. To process the sensory input and convert it into the appropriate behaviour, the box jellyfish have a central nervous system (CNS) but this is still poorly understood. The CNS has two major components: the rhopalial nervous system and the ring nerve. The rhopalial nervous system is situated within the rhopalia in close connection with the eyes, whereas the ring nerve encircles the bell. We describe the morphology of the ring nerve of the box jellyfish Tripedalia cystophora as ascertained by normal histological techniques, immunohistochemistry and transmission electron microscopy. By light microscopy, we have estimated the number of cells in the ring nerve by counting their nuclei. In cross sections at the ultrastructural level, the ring nerve appears to have three types of neurites: (1) small "normal"-looking neurites, (2) medium-sized neurites almost completely filled by electron-lucent vacuoles and (3) giant neurites. In general, only one giant neurite is seen on each section; this type displays the most synapses. Epithelial cells divide the ring nerve into compartments, each having a tendency to contain neurites of similar morphology. The number and arrangement of the compartments vary along the length of the ring nerve.

  17. Structure of certain near-rings

    OpenAIRE

    Murtaza A. Quadri; Ashraf, Mohd; Ali, Asma

    1992-01-01

    Recentemente Ligh e Luh $\\left[6\\right]$ hanno trovato una scomposizione in somma diretta per gli anelli che hanno la proprietà $\\left(xy\\right)^{n\\left(x,y\\right)}=xy$ usando la commutatività di questi anelli provata da Searcòid e MacHale $\\left[8\\right]$. In questo lavoro si continua questo studio e si ottiene una scomposizione per i quasi-anelli che hanno una qualunque delle proprietà $\\left(i\\right)\\left(xy\\right)^{n\\left(x,y\\right)}=xy\\left(ii\\right)x^{n\\left(x,y\\right)}y^...

  18. A close look at Saturn's rings with Cassini VIMS

    Science.gov (United States)

    Nicholson, P.D.; Hedman, M.M.; Clark, R.N.; Showalter, M.R.; Cruikshank, D.P.; Cuzzi, J.N.; Filacchione, G.; Capaccioni, F.; Cerroni, P.; Hansen, G.B.; Sicardy, B.; Drossart, P.; Brown, R.H.; Buratti, B.J.; Baines, K.H.; Coradini, A.

    2008-01-01

    Soon after the Cassini-Huygens spacecraft entered orbit about Saturn on 1 July 2004, its Visual and Infrared Mapping Spectrometer obtained two continuous spectral scans across the rings, covering the wavelength range 0.35-5.1 ??m, at a spatial resolution of 15-25 km. The first scan covers the outer C and inner B rings, while the second covers the Cassini Division and the entire A ring. Comparisons of the VIMS radial reflectance profile at 1.08 ??m with similar profiles at a wavelength of 0.45 ??m assembled from Voyager images show very little change in ring structure over the intervening 24 years, with the exception of a few features already known to be noncircular. A model for single-scattering by a classical, many-particle-thick slab of material with normal optical depths derived from the Voyager photopolarimeter stellar occultation is found to provide an excellent fit to the observed VIMS reflectance profiles for the C ring and Cassini Division, and an acceptable fit for the inner B ring. The A ring deviates significantly from such a model, consistent with previous suggestions that this region may be closer to a monolayer. An additional complication here is the azimuthally-variable average optical depth associated with "self-gravity wakes" in this region and the fact that much of the A ring may be a mixture of almost opaque wakes and relatively transparent interwake zones. Consistently with previous studies, we find that the near-infrared spectra of all main ring regions are dominated by water ice, with a typical regolith grain radius of 5-20 ??m, while the steep decrease in visual reflectance shortward of 0.6 ??m is suggestive of an organic contaminant, perhaps tholin-like. Although no materials other than H2O ice have been identified with any certainty in the VIMS spectra of the rings, significant radial variations are seen in the strength of the water-ice absorption bands. Across the boundary between the C and B rings, over a radial range of ???7000 km, the

  19. Autumn study on storage rings

    CERN Multimedia

    1974-01-01

    The first two weeks of October have seen storage ring people from accelerator Laboratories throughout the world at CERN to study the fundamental problems of very high energy protonproton colliding beam machines.

  20. $(n,m)$-SG rings

    OpenAIRE

    Bennis, Driss

    2009-01-01

    This paper is a continuation of the paper Int. Electron. J. Algebra 6 (2009), 219-227. Namely, we introduce and study a doubly filtered set of classes of rings of finite Gorenstein global dimension, which are called $(n,m)$-SG for integers $n\\geq 1$ and $m\\geq 0$. Examples of $(n,m)$-SG rings, for $n=1$ and 2 and every $m\\geq 0$, are given.