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Sample records for induces multipolar mitoses

  1. The Fate of Chrysotile-Induced Multipolar Mitosis and Aneuploid Population in Cultured Lung Cancer Cells

    PubMed Central

    de Araujo Cortez, Beatriz; Quassollo, Gonzalo; Caceres, Alfredo; Machado-Santelli, Glaucia Maria

    2011-01-01

    Chrysotile is one of the six types of asbestos, and it is the only one that can still be commercialized in many countries. Exposure to other types of asbestos has been associated with serious diseases, such as lung carcinomas and pleural mesotheliomas. The association of chrysotile exposure with disease is controversial. However, in vitro studies show the mutagenic potential of chrysotile, which can induce DNA and cell damage. The present work aimed to analyze alterations in lung small cell carcinoma cultures after 48 h of chrysotile exposure, followed by 2, 4 and 8 days of recovery in fiber-free culture medium. Some alterations, such as aneuploid cell formation, increased number of cells in G2/M phase and cells in multipolar mitosis were observed even after 8 days of recovery. The presence of chrysotile fibers in the cell cultures was detected and cell morphology was observed by laser scanning confocal microscopy. After 4 and 8 days of recovery, only a few chrysotile fragments were present in some cells, and the cellular morphology was similar to that of control cells. Cells transfected with the GFP-tagged α-tubulin plasmid were treated with chrysotile for 24 or 48 h and cells in multipolar mitosis were observed by time-lapse microscopy. Fates of these cells were established: retention in metaphase, cell death, progression through M phase generating more than two daughter cells or cell fusion during telophase or cytokinesis. Some of them were related to the formation of aneuploid cells and cells with abnormal number of centrosomes. PMID:21483691

  2. Multipolar mitosis of tetraploid cells: inhibition by p53 and dependency on Mos.

    PubMed

    Vitale, Ilio; Senovilla, Laura; Jemaà, Mohamed; Michaud, Mickaël; Galluzzi, Lorenzo; Kepp, Oliver; Nanty, Lisa; Criollo, Alfredo; Rello-Varona, Santiago; Manic, Gwenola; Métivier, Didier; Vivet, Sonia; Tajeddine, Nicolas; Joza, Nicholas; Valent, Alexander; Castedo, Maria; Kroemer, Guido

    2010-04-07

    Tetraploidy can constitute a metastable intermediate between normal diploidy and oncogenic aneuploidy. Here, we show that the absence of p53 is not only permissive for the survival but also for multipolar asymmetric divisions of tetraploid cells, which lead to the generation of aneuploid cells with a near-to-diploid chromosome content. Multipolar mitoses (which reduce the tetraploid genome to a sub-tetraploid state) are more frequent when p53 is downregulated and the product of the Mos oncogene is upregulated. Mos inhibits the coalescence of supernumerary centrosomes that allow for normal bipolar mitoses of tetraploid cells. In the absence of p53, Mos knockdown prevents multipolar mitoses and exerts genome-stabilizing effects. These results elucidate the mechanisms through which asymmetric cell division drives chromosomal instability in tetraploid cells.

  3. Multipolar mitosis of tetraploid cells: inhibition by p53 and dependency on Mos

    PubMed Central

    Vitale, Ilio; Senovilla, Laura; Jemaà, Mohamed; Michaud, Mickaël; Galluzzi, Lorenzo; Kepp, Oliver; Nanty, Lisa; Criollo, Alfredo; Rello-Varona, Santiago; Manic, Gwenola; Métivier, Didier; Vivet, Sonia; Tajeddine, Nicolas; Joza, Nicholas; Valent, Alexander; Castedo, Maria; Kroemer, Guido

    2010-01-01

    Tetraploidy can constitute a metastable intermediate between normal diploidy and oncogenic aneuploidy. Here, we show that the absence of p53 is not only permissive for the survival but also for multipolar asymmetric divisions of tetraploid cells, which lead to the generation of aneuploid cells with a near-to-diploid chromosome content. Multipolar mitoses (which reduce the tetraploid genome to a sub-tetraploid state) are more frequent when p53 is downregulated and the product of the Mos oncogene is upregulated. Mos inhibits the coalescence of supernumerary centrosomes that allow for normal bipolar mitoses of tetraploid cells. In the absence of p53, Mos knockdown prevents multipolar mitoses and exerts genome-stabilizing effects. These results elucidate the mechanisms through which asymmetric cell division drives chromosomal instability in tetraploid cells. PMID:20186124

  4. v-Src-induced nuclear localization of YAP is involved in multipolar spindle formation in tetraploid cells.

    PubMed

    Kakae, Keiko; Ikeuchi, Masayoshi; Kuga, Takahisa; Saito, Youhei; Yamaguchi, Naoto; Nakayama, Yuji

    2017-01-01

    The protein-tyrosine kinase, c-Src, is involved in a variety of signaling events, including cell division. We have reported that v-Src, which is a mutant variant of the cellular proto-oncogene, c-Src, causes delocalization of Aurora B kinase, resulting in a furrow regression in cytokinesis and the generation of multinucleated cells. However, the effect of v-Src on mitotic spindle formation is unknown. Here we show that v-Src-expressing HCT116 and NIH3T3 cells undergo abnormal cell division, in which cells separate into more than two cells. Upon v-Src expression, the proportion of multinucleated cells is increased in a time-dependent manner. Flow cytometry analysis revealed that v-Src increases the number of cells having a ≥4N DNA content. Microscopic analysis showed that v-Src induces the formation of multipolar spindles with excess centrosomes. These results suggest that v-Src induces multipolar spindle formation by generating multinucleated cells. Tetraploidy activates the tetraploidy checkpoint, leading to a cell cycle arrest of tetraploid cells at the G1 phase, in which the nuclear exclusion of the transcription co-activator YAP plays a critical role. In multinucleated cells that are induced by cytochalasin B and the Plk1 inhibitor, YAP is excluded from the nucleus. However, v-Src prevents this nuclear exclusion of YAP through a decrease in the phosphorylation of YAP at Ser127 in multinucleated cells. Furthermore, v-Src decreases the expression level of p53, which also plays a critical role in the cell cycle arrest of tetraploid cells. These results suggest that v-Src promotes abnormal spindle formation in at least two ways: generation of multinucleated cells and a weakening of the tetraploidy checkpoint.

  5. Expression of the novel maternal centrosome assembly factor Wdr8 is required for vertebrate embryonic mitoses

    PubMed Central

    Inoue, Daigo; Stemmer, Manuel; Thumberger, Thomas; Ruppert, Thomas; Bärenz, Felix; Wittbrodt, Joachim; Gruss, Oliver J.

    2017-01-01

    The assembly of the first centrosome occurs upon fertilisation when male centrioles recruit pericentriolar material (PCM) from the egg cytoplasm. The mechanisms underlying the proper assembly of centrosomes during early embryogenesis remain obscure. We identify Wdr8 as a novel maternally essential protein that is required for centrosome assembly during embryonic mitoses of medaka (Oryzias latipes). By CRISPR–Cas9-mediated knockout, maternal/zygotic Wdr8-null (m/zWdr8−/−) blastomeres exhibit severe defects in centrosome structure that lead to asymmetric division, multipolar mitotic spindles and chromosome alignment errors. Via its WD40 domains, Wdr8 interacts with the centriolar satellite protein SSX2IP. Combining targeted gene knockout and in vivo reconstitution of the maternally essential Wdr8–SSX2IP complex reveals an essential link between maternal centrosome proteins and the stability of the zygotic genome for accurate vertebrate embryogenesis. Our approach provides a way of distinguishing maternal from paternal effects in early embryos and should contribute to understanding molecular defects in human infertility. PMID:28098238

  6. Multipolar optically induced electric and magnetic resonances in the ellipsoidal nanoparticles

    NASA Astrophysics Data System (ADS)

    Reena; Devi, Inder; Kalra, Yogita; Sinha, R. K.

    2016-09-01

    In this paper, electric and magnetic resonances induced in the ellipsoidal dielectric nanoparticles in the optical range have been analyzed. Circular displacement currents excited inside the elliptical nano-particles by the incident light result in magnetic dipolar resonance in the dielectric nanoparticles. Kerker's type scattering is observed due to the mutual interference of electric and magnetic resonances. The effect on the resonance conditions with the variation in the relative permittivity from Er= 5 to Er= 20 of the ellipsoidal nanoparticle has been observed. It has been analyzed that peaks of electric and magnetic resonances come closer by decreasing the electric permittivity of the nanoparticle, which leads to the increase in the directionality in the forward direction, as verified using Generalized Kerker's condition. Further, far field scattering patterns have been obtained using the finite element method. Here, the electric and magnetic resonances have been optically induced up to quadrupolar modes. There is enhancement of the directionality in the forward direction when electric and magnetic resonances are in phase. Further, the effect of size of the linear array of ellipsoidal nanoparticles on the directionality has been analyzed. It has been observed that there is increase in the directivity by increasing the chain of the nanoparticles. Thus, the ellipsoidal nanoparticles can lead to the design of low loss and highly directional optical nanoantennas.

  7. Multipolar ECR plasma characterization

    SciTech Connect

    Ciubotariu, C.I.; Golovanivsky, K.S.; Bacal, M.

    1995-12-31

    There has been considerable interest in the development of intense negative ion sources for use in high-energy neutral beam heating and diagnostics systems for nuclear fusion plasmas. As it was shown by one of the authors overdense ECR plasmas seem to be an appropriate medium to produce H-ions at high rate. Overdense plasmas are a result of the microwave({mu}wave) power absorption in ECR plasma heating and magnetic field confinement. Our aim is to characterize the hydrogen plasma produced in a 2.45 GHz multipolar negative ion ECR source (ECRIN).

  8. Zygotic expression of the pebble locus is required for cytokinesis during the postblastoderm mitoses of Drosophila.

    PubMed

    Hime, G; Saint, R

    1992-01-01

    Mutations at the pebble locus of Drosophila melanogaster result in embryonic lethality. Examination of homozygous mutant embryos at the end of embryogenesis revealed the presence of fewer and larger cells which contained enlarged nuclei. Characterization of the embryonic cell cycles using DAPI, propidium iodide, anti-tubulin and anti-spectrin staining showed that the first thirteen rapid syncytial nuclear divisions proceeded normally in pebble mutant embryos. Following cellularization, the postblastoderm nuclear divisions occurred (mitoses 14, 15 and 16), but cytokinesis was never observed. Multinucleate cells and duplicate mitotic figures were seen within single cells at the time of the cycle 15 mitoses. We conclude that zygotic expression of the pebble gene is required for cytokinesis following cellularization during Drosophila embryogenesis. We postulate that developmental regulation of zygotic transcription of the pebble gene is a consequence of the transition from syncytial to cellular mitoses during cycle 14 of embryogenesis.

  9. Nonrandom frequency distribution of mitoses in rat lobuloaveolar mammary gland epithelium.

    PubMed Central

    Purnell, D. M.; Stowers, D. J.

    1977-01-01

    A quantitative microscopic technique was employed to examine the distribution of mitotic activity in the rat mammary gland. The frequency distribution of mitoses per unit volume of lobuloalveolar mammary gland epithelium in virgin Lewis/Mai rats at each phase of the estrous cycle were determined and compared to the expected Poisson frequency distributions, assuming random mitotic activity. Both pooled data and data from individual rats were compared to expected Poisson distributions. At each phase of the estrous cycle, the pooled observed distributions deviated significantly from Poisson distributions. Sixty-seven percent (72/108) of the observed frequency distributions obtained from individual rats also deviated significantly from expected Poisson distributions. These data indicate a nonrandom distribution of mitoses in rat lobuloalveolar mammary gland epithelium. This observation suggests that local cell products and/or a variation in the extent of replicative synchrony of lobuloalveolar cell populations may determine in part the pattern of mitotic activity in this tissue. A nonrandom distribution of mitoses in mammary epithelium may have significance in relation to the genesis of hyperplastic and neoplastic lesions of the mammary gland. PMID:560125

  10. Multipolar interference effects in nanophotonics.

    PubMed

    Liu, Wei; Kivshar, Yuri S

    2017-03-28

    Scattering of electromagnetic waves by an arbitrary nanoscale object can be characterized by a multipole decomposition of the electromagnetic field that allows one to describe the scattering intensity and radiation pattern through interferences of dominating multipole modes excited. In modern nanophotonics, both generation and interference of multipole modes start to play an indispensable role, and they enable nanoscale manipulation of light with many related applications. Here, we review the multipolar interference effects in metallic, metal-dielectric and dielectric nanostructures, and suggest a comprehensive view on many phenomena involving the interferences of electric, magnetic and toroidal multipoles, which drive a number of recently discussed effects in nanophotonics such as unidirectional scattering, effective optical antiferromagnetism, generalized Kerker scattering with controlled angular patterns, generalized Brewster angle, and non-radiating optical anapoles. We further discuss other types of possible multipolar interference effects not yet exploited in the literature and envisage the prospect of achieving more flexible and advanced nanoscale control of light relying on the concepts of multipolar interference through full phase and amplitude engineering.This article is part of the themed issue 'New horizons for nanophotonics'.

  11. Cytological characteristics and classification of spindle inhibitors according to their effects on segmentation mitoses.

    PubMed

    Sentein, P; Ates, Y

    1978-01-01

    The effects of spindle inhibitors and of protein synthesis inhibitors on segmentation mitoses allow us to classify them into six groups : 1. Colchicine type : destruction of the whole achromatic apparatus and centrospheres without storing of dense bodies; 2. Quinoline type : same effect on the achromatic apparatus, but blocked centrospheres with accumulation of dense bodies; 3. Chloralhydrate type : Incomplete destruction of achromatic apparatus, spindle residue which maintains the chromosomes in a star shape, inactive centrospheres sequestered by the reticulum, but without accumulation of dense bodies; 4. Phenylurethane type : Incomplete and reversible action, which leads to easy production of pluripolar mitoses; 5. Carboxylic acid type : dissociation of the spindle, sometimes with blocking of the centrosphere, together with profound chromosome changes without primitive breaks; the intensity and quality of their action is related to the number of carbon atoms in the acid considered; 6. Protein synthesis inhibitor type : (cycloheximide, pederin) characterized by a stop of the nuclear cycle at telo-prophase when the action is sufficient, chromosome abnormalities, sometimes, reduced to strings of beads, and freeing of asters; at weaker concentrations mitosis is possible, but the congression of chromosomes at the equator is abnormal because of functional disturbance of the kinetochores. The nature and grading of these effects, their association (or non - association) to chromosome damage, the soundness of the spindle when only the chromosomes are affected (nitrogen mustard) make this one of the tests which gives the most specific data about the action of antimitotic substances.

  12. Libration-driven multipolar instabilities

    NASA Astrophysics Data System (ADS)

    Cébron, D.; Vantieghem, S.; Herreman, W.

    2014-01-01

    We consider rotating flows in non-axisymmetric enclosures that are driven by libration, i.e. by a small periodic modulation of the rotation rate. Thanks to its simplicity, this model is relevant to various contexts, from industrial containers (with small oscillations of the rotation rate) to fluid layers of terrestial planets (with length-of-day variations). Assuming a multipolar $n$-fold boundary deformation, we first obtain the two-dimensional basic flow. We then perform a short-wavelength local stability analysis of the basic flow, showing that an instability may occur in three dimensions. We christen it the Libration Driven Multipolar Instability (LDMI). The growth rates of the LDMI are computed by a Floquet analysis in a systematic way, and compared to analytical expressions obtained by perturbation methods. We then focus on the simplest geometry allowing the LDMI, a librating deformed cylinder. To take into account viscous and confinement effects, we perform a global stability analysis, which shows that the LDMI results from a parametric resonance of inertial modes. Performing numerical simulations of this librating cylinder, we confirm that the basic flow is indeed established and report the first numerical evidence of the LDMI. Numerical results, in excellent agreement with the stability results, are used to explore the non-linear regime of the instability (amplitude and viscous dissipation of the driven flow). We finally provide an example of LDMI in a deformed spherical container to show that the instability mechanism is generic. Our results show that the previously studied libration driven elliptical instability simply corresponds to the particular case $n=2$ of a wider class of instabilities. Summarizing, this work shows that any oscillating non-axisymmetric container in rotation may excite intermittent, space-filling LDMI flows, and this instability should thus be easy to observe experimentally.

  13. Designing Multipolar Resonances in Dielectric Metamaterials

    PubMed Central

    Butakov, Nikita A.; Schuller, Jon A.

    2016-01-01

    Dielectric resonators form the building blocks of nano-scale optical antennas and metamaterials. Due to their multipolar resonant response and low intrinsic losses they offer design flexibility and high-efficiency performance. These resonators are typically described in terms of a spherical harmonic decomposition with Mie theory. In experimental realizations however, a departure from spherical symmetry and the use of high-index substrates leads to new features appearing in the multipolar response. To clarify this behavior, we present a systematic experimental and numerical characterization of Silicon disk resonators. We demonstrate that for disk resonators on low-index quartz substrates, the electric and magnetic dipole modes are easily identifiable across a wide range of aspect-ratios, but that higher order peaks cannot be unambiguously associated with any specific multipolar mode. On high-index Silicon substrates, even the fundamental dipole modes do not have a clear association. When arranged into arrays, resonances are shifted and pronounced preferential forward and backward scattering conditions appear, which are not as apparent in individual resonators and may be associated with interference between multipolar modes. These findings present new opportunities for engineering the multipolar scattering response of dielectric optical antennas and metamaterials, and provide a strategy for designing nano-optical components with unique functionalities. PMID:27929038

  14. Designing Multipolar Resonances in Dielectric Metamaterials

    NASA Astrophysics Data System (ADS)

    Butakov, Nikita A.; Schuller, Jon A.

    2016-12-01

    Dielectric resonators form the building blocks of nano-scale optical antennas and metamaterials. Due to their multipolar resonant response and low intrinsic losses they offer design flexibility and high-efficiency performance. These resonators are typically described in terms of a spherical harmonic decomposition with Mie theory. In experimental realizations however, a departure from spherical symmetry and the use of high-index substrates leads to new features appearing in the multipolar response. To clarify this behavior, we present a systematic experimental and numerical characterization of Silicon disk resonators. We demonstrate that for disk resonators on low-index quartz substrates, the electric and magnetic dipole modes are easily identifiable across a wide range of aspect-ratios, but that higher order peaks cannot be unambiguously associated with any specific multipolar mode. On high-index Silicon substrates, even the fundamental dipole modes do not have a clear association. When arranged into arrays, resonances are shifted and pronounced preferential forward and backward scattering conditions appear, which are not as apparent in individual resonators and may be associated with interference between multipolar modes. These findings present new opportunities for engineering the multipolar scattering response of dielectric optical antennas and metamaterials, and provide a strategy for designing nano-optical components with unique functionalities.

  15. Both Cyclin B levels and DNA-replication checkpoint control the early embryonic mitoses in Drosophila

    PubMed Central

    Ji, Jun-Yuan; Squirrell, Jayne M.; Schubiger, Gerold

    2013-01-01

    Summary The earliest embryonic mitoses in Drosophila, as in other animals except mammals, are viewed as synchronous and of equal duration. However, we observed that total cell-cycle length steadily increases after cycle 7, solely owing to the extension of interphase. Between cycle 7 and cycle 10, this extension is DNA-replication checkpoint independent, but correlates with the onset of Cyclin B oscillation. In addition, nuclei in the middle of embryos have longer metaphase and shorter anaphase than nuclei at the two polar regions. Interestingly, sister chromatids move faster in anaphase in the middle than the posterior region. These regional differences correlate with local differences in Cyclin B concentration. After cycle 10, interphase and total cycle duration of nuclei in the middle of the embryo are longer than at the poles. Because interphase also extends in checkpoint mutant (grapes) embryo after cycle 10, although less dramatic than wild-type embryos, interphase extension after cycle 10 is probably controlled by both Cyclin B limitation and the DNA-replication checkpoint. PMID:14681192

  16. p53 Dependent Centrosome Clustering Prevents Multipolar Mitosis in Tetraploid Cells

    PubMed Central

    Yi, Qiyi; Zhao, Xiaoyu; Huang, Yun; Ma, Tieliang; Zhang, Yingyin; Hou, Heli; Cooke, Howard J.; Yang, Da-Qing; Wu, Mian; Shi, Qinghua

    2011-01-01

    Background p53 abnormality and aneuploidy often coexist in human tumors, and tetraploidy is considered as an intermediate between normal diploidy and aneuploidy. The purpose of this study was to investigate whether and how p53 influences the transformation from tetraploidy to aneuploidy. Principal Findings Live cell imaging was performed to determine the fates and mitotic behaviors of several human and mouse tetraploid cells with different p53 status, and centrosome and spindle immunostaining was used to investigate centrosome behaviors. We found that p53 dominant-negative mutation, point mutation, or knockout led to a 2∼ 33-fold increase of multipolar mitosis in N/TERT1, 3T3 and mouse embryonic fibroblasts (MEFs), while mitotic entry and cell death were not significantly affected. In p53-/- tetraploid MEFs, the ability of centrosome clustering was compromised, while centrosome inactivation was not affected. Suppression of RhoA/ROCK activity by specific inhibitors in p53-/- tetraploid MEFs enhanced centrosome clustering, decreased multipolar mitosis from 38% to 20% and 16% for RhoA and ROCK, respectively, while expression of constitutively active RhoA in p53+/+ tetraploid 3T3 cells increased the frequency of multipolar mitosis from 15% to 35%. Conclusions p53 could not prevent tetraploid cells entering mitosis or induce tetraploid cell death. However, p53 abnormality impaired centrosome clustering and lead to multipolar mitosis in tetraploid cells by modulating the RhoA/ROCK signaling pathway. PMID:22076149

  17. Perturbation theory for multipolar discrete fluids.

    PubMed

    Benavides, Ana L; Gámez, Francisco

    2011-10-07

    An analytical expression for the Helmholtz free energy of discrete multipolar potentials as a function of density, temperature, and intermolecular parameters is obtained as an extension of the multipolar square-well perturbation theory [A. L. Benavides, Y. Guevara, and F. del Río, Physica A 202, 420 (1994)]. The presented procedure is suitable for the description of a more general intermolecular potential model taking into account the overlap and dispersion forces through a discrete potential represented by a sequence of square-shoulders and wells, as well as electrostatic interactions. The main advantage of this approach is that since the Helmholtz free energy is given as an explicit expression in terms of the intermolecular parameters characterizing the interaction, the properties of interest can be easily obtained through usual thermodynamic relations. Besides, since a great variety of discretized potentials can be used with this equation of state, its applicability is very vast. By varying the intermolecular parameters, some illustrative cases are considered, and their phase diagrams are tested against available simulation data. It is found that this theoretical approach is able to reproduce qualitatively and quantitatively well the vapor-liquid equilibrium of the chosen potentials with different multipole moment of varied strengths, except in the critical region.

  18. Perturbation theory for multipolar discrete fluids

    NASA Astrophysics Data System (ADS)

    Benavides, Ana L.; Gámez, Francisco

    2011-10-01

    An analytical expression for the Helmholtz free energy of discrete multipolar potentials as a function of density, temperature, and intermolecular parameters is obtained as an extension of the multipolar square-well perturbation theory [A. L. Benavides, Y. Guevara, and F. del Río, Physica A 202, 420 (1994), 10.1016/0378-4371(94)90469-3]. The presented procedure is suitable for the description of a more general intermolecular potential model taking into account the overlap and dispersion forces through a discrete potential represented by a sequence of square-shoulders and wells, as well as electrostatic interactions. The main advantage of this approach is that since the Helmholtz free energy is given as an explicit expression in terms of the intermolecular parameters characterizing the interaction, the properties of interest can be easily obtained through usual thermodynamic relations. Besides, since a great variety of discretized potentials can be used with this equation of state, its applicability is very vast. By varying the intermolecular parameters, some illustrative cases are considered, and their phase diagrams are tested against available simulation data. It is found that this theoretical approach is able to reproduce qualitatively and quantitatively well the vapor-liquid equilibrium of the chosen potentials with different multipole moment of varied strengths, except in the critical region.

  19. Arbitrary order permanent Cartesian multipolar electrostatic interactions

    NASA Astrophysics Data System (ADS)

    Boateng, H. A.; Todorov, I. T.

    2015-01-01

    Recently, there has been a concerted effort to implement advanced classical potential energy surfaces by adding higher order multipoles to fixed point charge electrostatics in a bid to increase the accuracy of simulations of condensed phase systems. One major hurdle is the unwieldy nature of the expressions which in part has limited developers mostly to including only dipoles and quadrupoles. In this paper, we present a generalization of the Cartesian formulation of electrostatic multipolar interactions that enables the specification of an arbitrary order of multipoles. Specifically, we derive formulas for arbitrary order implementation of the particle mesh Ewald method and give a closed form formula for the stress tensor in the reciprocal space. In addition, we provide recurrence relations for common electrostatic potentials employed in molecular simulations, which allows for the generalization to arbitrary order and guarantees a computational cost that scales as O(p3) for Cartesian multipole interactions of order p.

  20. Forest discrimination with multipolarization imaging radar

    NASA Technical Reports Server (NTRS)

    Ford, J. P.; Wickland, D. E.

    1985-01-01

    The relations between polarization signatures and biophysical characteristics through a range of different forest environments were investigated using airborne synthetic-aperture (SAR) images acquired at L-band on March 1, 1984 in South Carolina. SAR data acquired in four linear polarization states with 10-m spatial resolution were encoded as color composite images and compared to US Forest Service forest stand data. The most useful correlative forest data were stand basal area, forest age, site condition index, and forest management type. It is found that the multipolarization images discriminate variation in tree density or difference in the amount of understory, but no evidence has been found for discrimination between evergreen and deciduous forest types.

  1. Forest discrimination with multipolarization imaging radar

    NASA Technical Reports Server (NTRS)

    Ford, J. P.; Wickland, D. E.

    1985-01-01

    The use of radar polarization diversity for discriminating forest canopy variables on airborne synthetic-aperture radar (SAR) images is evaluated. SAR images were acquired at L-Band (24.6 cm) simultaneously in four linear polarization states (HH, HV, VH, and VV) in South Carolina on March 1, 1984. In order to relate the polarization signatures to biophysical properties, false-color composite images were compared to maps of forest stands in the timber compartment. In decreasing order, the most useful correlative forest data are stand basal area, forest age, site condition index, and forest management type. It is found that multipolarization images discriminate variation in tree density and difference in the amount of understory, but do not discriminate between evergreen and deciduous forest types.

  2. A novel network of multipolar bursting interneurons generates theta frequency oscillations in neocortex.

    PubMed

    Blatow, Maria; Rozov, Andrei; Katona, Istvan; Hormuzdi, Sheriar G; Meyer, Axel H; Whittington, Miles A; Caputi, Antonio; Monyer, Hannah

    2003-06-05

    GABAergic interneurons can phase the output of principal cells, giving rise to oscillatory activity in different frequency bands. Here we describe a new subtype of GABAergic interneuron, the multipolar bursting (MB) cell in the mouse neocortex. MB cells are parvalbumin positive but differ from fast-spiking multipolar (FS) cells in their morphological, neurochemical, and physiological properties. MB cells are reciprocally connected with layer 2/3 pyramidal cells and are coupled with each other by chemical and electrical synapses. MB cells innervate FS cells but not vice versa. MB to MB cell as well as MB to pyramidal cell synapses exhibit paired-pulse facilitation. Carbachol selectively induced synchronized theta frequency oscillations in MB cells. Synchrony required both gap junction coupling and GABAergic chemical transmission, but not excitatory glutamatergic input. Hence, MB cells form a distinct inhibitory network, which upon cholinergic drive can generate rhythmic and synchronous theta frequency activity, providing temporal coordination of pyramidal cell output.

  3. MULTIPOLAR PLANETARY NEBULAE: NOT AS GEOMETRICALLY DIVERSIFIED AS THOUGHT

    SciTech Connect

    Chong, S.-N.; Imai, H.; Chibueze, J.; Kwok, Sun; Tafoya, D. E-mail: sunkwok@hku.hk

    2012-12-01

    Planetary nebulae (PNe) have diverse morphological shapes, including point-symmetric and multipolar structures. Many PNe also have complicated internal structures such as tori, lobes, knots, and ansae. A complete accounting of all the morphological structures through physical models is difficult. A first step toward such an understanding is to derive the true three-dimensional structure of the nebulae. In this paper, we show that a multipolar nebula with three pairs of lobes can explain many such features, if orientation and sensitivity effects are taken into account. Using only six parameters-the inclination and position angles of each pair-we are able to simulate the observed images of 20 PNe with complex structures. We suggest that multipolar structure is an intrinsic structure of PNe and the statistics of multipolar PNe have been severely underestimated in the past.

  4. Geological applications of multipolarization SAR data

    NASA Technical Reports Server (NTRS)

    Evans, Diane L.

    1986-01-01

    Spaceborne Synthetic Aperture Radar (SAR) data acquired by SEASAT and the Shuttle Imaging Radar (SIR-A/B) operating at L-band with HH polarization were found to be useful in conjunction with other sensors for lithologic discrimination in arid environments with limited vegetation cover. In order to assess the utility of more advanced sensors for geologic research and define the unique contributions each sensor makes, remote sensing data were collected over the Deadman Butte area of the Wind River Basin, Wyoming. The Wind River Basin is an asymmetric sedimentary basin in central Wyoming created during the early Eocene Laramide orogeny. The stratigraphic section of the Deadman Butte study area, which was measured by Woodward is made up of Paleozoic and Mesozoic marine shales, siltstones, limestones, and sandstones. Sensor systems included LANDSAT 4 Thematic Mapper (TM), Thermal Infrared Multispectral Scanner (TIMS) and the Multipolarization, L-band airborne SAR, a prototype for the next Shuttle Imaging Radar (SIR-C). Sensor parameters are given.

  5. The multipolar stage and disruptions in neuronal migration.

    PubMed

    LoTurco, Joseph J; Bai, Jilin

    2006-07-01

    The genetic basis is now known for several disorders of neuronal migration in the developing cerebral cortex. Identification of the cellular processes mediated by the implicated genes is revealing crucial stages of neuronal migration and has the potential to reveal common cellular causes of neuronal migration disorders. We hypothesize that a newly recognized morphological stage of neuronal migration, the multipolar stage, is vulnerable and is disrupted in several disorders of neocortical development. The multipolar stage occurs as bipolar progenitor cells become radially migrating neurons. Several studies using in utero electroporation and RNAi have revealed that transition out of the multipolar stage depends on the function of filamin A, LIS1 and DCX. Mutations in the genes encoding these proteins in humans cause distinct neuronal migration disorders, including periventricular nodular heterotopia, subcortical band heterotopia and lissencephaly. The multipolar stage therefore seems to be a critical point of migration control and a vulnerable target for disruption of neocortical development. This review is part of the INMED/TINS special issue "Nature and nurture in brain development and neurological disorders", based on presentations at the annual INMED/TINS symposium (http://inmednet.com/).

  6. Excitation of dark multipolar plasmonic resonances at terahertz frequencies

    PubMed Central

    Chen, Lin; Wei, YuMing; Zang, XiaoFei; Zhu, YiMing; Zhuang, SongLin

    2016-01-01

    We experimentally observe the excitation of dark multipolar spoof localized surface plasmon resonances in a hybrid structure consisting of a corrugated metallic disk coupled with a C-shaped dipole resonator. The uncoupled corrugated metallic disk only supports a dipolar resonance in the transmission spectrum due to perfect symmetry of the structure. However, the dark multipolar spoof localized surface plasmon resonances emerge when coupled with a bright C-shaped resonator which is placed in the vicinity of the corrugated metallic disk. These excited multipolar resonances show minimum influence on the coupling distance between the C-shaped resonator and corrugated metallic disk. The resonance frequencies of the radiative modes are controlled by varying the angle of the C-shaped resonator and the inner disk radius, both of which play dominant roles in the excitation of the spoof localized surface plasmons. Observation of such a transition from the dark to radiative nature of multipolar spoof localized plasmon resonances would find potential applications in terahertz based resonant plasmonic and metamaterial devices. PMID:26903382

  7. Strategies for Business Schools in a Multi-Polar World

    ERIC Educational Resources Information Center

    Dameron, Stephanie; Durand, Thomas

    2013-01-01

    Purpose: The purpose of this paper is to examine the contours of the emerging business education and institutions in a multi-polar world and to identify the causes of the strategic convergence of management education, to explore the limitations of the dominant models of management education and to propose a range of strategic alternatives for…

  8. Excitation of dark multipolar plasmonic resonances at terahertz frequencies

    NASA Astrophysics Data System (ADS)

    Chen, Lin; Wei, Yuming; Zang, Xiaofei; Zhu, Yiming; Zhuang, Songlin

    2016-02-01

    We experimentally observe the excitation of dark multipolar spoof localized surface plasmon resonances in a hybrid structure consisting of a corrugated metallic disk coupled with a C-shaped dipole resonator. The uncoupled corrugated metallic disk only supports a dipolar resonance in the transmission spectrum due to perfect symmetry of the structure. However, the dark multipolar spoof localized surface plasmon resonances emerge when coupled with a bright C-shaped resonator which is placed in the vicinity of the corrugated metallic disk. These excited multipolar resonances show minimum influence on the coupling distance between the C-shaped resonator and corrugated metallic disk. The resonance frequencies of the radiative modes are controlled by varying the angle of the C-shaped resonator and the inner disk radius, both of which play dominant roles in the excitation of the spoof localized surface plasmons. Observation of such a transition from the dark to radiative nature of multipolar spoof localized plasmon resonances would find potential applications in terahertz based resonant plasmonic and metamaterial devices.

  9. Multipolar electromagnetic fields around neutron stars: exact vacuum solutions and related properties

    NASA Astrophysics Data System (ADS)

    Pétri, J.

    2015-06-01

    The magnetic field topology in the surrounding of neutron stars is one of the key questions in pulsar magnetospheric physics. A very extensive literature exists about the assumption of a dipolar magnetic field but very little progress has been made in attempts to include multipolar components in a self-consistent way. In this paper, we study the effect of multipolar electromagnetic fields anchored in the star. We give exact analytical solutions in closed form for any order l and apply them to the retarded point quadrupole (l = 2), hexapole (l = 3) and octopole (l = 4), a generalization of the retarded point dipole (l = 1). We also compare the Poynting flux from each multipole and show that the spin-down luminosity depends on the ratio R/rL, R being the neutron star radius and rL the light-cylinder radius. Therefore the braking index also depends on R/rL. As such multipole fields possess very different topology, most importantly smaller length scales compared to the dipolar field, especially close to the neutron star, we investigate the deformation of the polar caps induced by these multipolar fields. Such fields could have a strong impact on the interpretation of the pulsed radio emission suspected to emanate from these polar caps as well as on the inferred geometry deduced from the high-energy light-curve fitting and on the magnetic field strength. Discrepancies between the two-pole caustic model and our new multipole caustic model are emphasized with the quadrupole field. To this respect, we demonstrate that working with only a dipole field can be very misleading.

  10. Requirement of mitoses for the reversal of X-inactivation in cell hybrids between murine embryonal carcinoma cells and normal female thymocytes

    SciTech Connect

    Takagi, N. )

    1988-04-01

    By means of a 5-bromodeoxyuridine (BrdU) incorporation and acridine orange fluorescence staining method the authors studied reactivation of the inactivated X chromosome (X{sub i}) in newly formed cell hybrids between the near-diploid HPRT-deficient OTF9-63 murine embryonal carcinoma cell (ECC) with an XO sex chromosome constitution and the normal female mouse thymocyte. Synchronization of the late replicating S chromosome in such hybrid cells, indicative of reactivation, was found for the first time on Day 3, and the frequency of reactivation was attained 90% on Day 5. Inhibition of cell cycle progression either by methylglyoxal bis(guanylhydrazone) dihydrochloride, an inhibitor of polyamine metabolism, or by isoleucine-deficient medium after cell fusion delayed reactivation of the X{sub i}, which implied that the number of cell division cycles traversed by individual cells rather than the length of time after cell fusion is critical for the reactivation. Double-labeling experiments using ({sup 3}H)thymidine and BrdU indicated that hybrid cells had undergone three or four mitoses before reactivation of the X{sub i}. Most probably reactivation of the X{sub i} is consequent to reversion of the thymocyte genome to an undifferentiated state under the influence of OTF9 genome. DNA demethylation or dilution of X{sub i}-specific factors by mitoses may be involved in this process.

  11. From dipolar to multipolar interactions between ultracold Feshbach molecules

    NASA Astrophysics Data System (ADS)

    Quéméner, Goulven; Lepers, Maxence; Luc-Koenig, Eliane; Dulieu, Olivier

    2016-05-01

    Using the multipolar expansion of electrostatic and magnetostatic potential energies, we characterize the long-range interactions between two weakly-bound diatomic molecules, taking as an example the paramagnetic Er2 Feshbach molecules which were produced recently. The interaction between atomic magnetic dipoles gives rise to the usual R-3 leading term of the multipolar expansion, where R is the intermolecular distance. We show that additional terms scaling as R-5, R-7 and so on also appear, which are strongly anisotropic with respect to the orientation of the molecules. These terms can be seen as effective molecular multipole moments reflecting the spatial extension of the molecules which is non-negligible compared to R. We acknowledge the financial support of the COPOMOL project (ANR-13-IS04-0004) from Agence Nationale de la Recherche.

  12. Mapping diverse forest cover with multipolarization airborne radar

    NASA Technical Reports Server (NTRS)

    Ford, J. P.; Wickland, D. E.; Sharitz, R. R.

    1985-01-01

    Imaging radar backscatter in continuously forested areas contains information about the forest canopy; it also contains data about topography, landforms, and terrain texture. For purposes of radar image interpretation and geologic mapping researchers were interested in identifying and separating forest canopy effects from geologic or geomorphic effects on radar images. The objectives of this investigation was to evaluate forest canopy variables in multipolarization radar images under conditions where geologic and topographic variables are at a minimum. A subsidiary objective was to compare the discriminatory capabilities of the radar images with corresponding optical images of similar spatial resolution. It appears that the multipolarization images discriminate variation in tree density, but no evidence was found for discrimination between evergreen and deciduous forest types.

  13. The emerging multi-polar world and China's grand game

    SciTech Connect

    Gupta, Rajan

    2011-01-19

    This talk outlines a scenario describing an emerging multipolar world that is aligned with geographical regions. The stability and security of this multipolar world is examined with respect to demographics, trade (economics), resource constraints, and development. In particular I focus on Asia which has two large countries, China and India, competing for resources and markets and examine the emerging regional relations, opportunities and threats. These relationships must overcome many hurdles - the Subcontinent is in a weak position politically and strategically and faces many threats, and China's growing power could help stabilize it or create new threats. Since the fate of 1.5 billion (2.4 billion by 2050) people depends on how the Subcontinent evolves, this talk is meant to initiates a discussion of what China and India can do to help the region develop and stabilize.

  14. Okadaic acid mediates p53 hyperphosphorylation and growth arrest in cells with wild-type p53 but increases aberrant mitoses in cells with non-functional p53.

    PubMed

    Milczarek, G J; Chen, W; Gupta, A; Martinez, J D; Bowden, G T

    1999-06-01

    The protein phosphatase inhibitor and tumor promoting agent okadaic acid (OA), has been shown previously to induce hyperphosphorylation of p53 protein, which in turn correlated with increased transactivation or apoptotic function. However, how the tumor promotion effects of OA relate to p53 tumor supressor function (or dysfunction) remain unclear. Rat embryonic fibroblasts harboring a temperature-sensitive mouse p53 transgene were treated with 50 nM doses of OA. At the wild-type permissive temperature this treatment resulted in: (i) the hyperphosphorylation of sites within tryptic peptides of the transactivation domain of p53; (ii) an increase in p53 affinity for a p21(waf1) promotor oligonucleotide; (iii) an increase in cellular steady state levels of p21(waf1) message; (iv) a G2/M cell cycle blockage in addition to the G1/S arrest previously associated with p53; and (v) no increased incidence of apoptosis. On the other hand, OA treatment at the mutated p53 permissive temperature resulted in a relatively high incidence of aberrant mitosis with no upregulation of p21(waf1) message. These results suggest that while wild-type p53 blocks the proliferative effects of OA through p21(waf1)-mediated growth arrest, cells with non-functional p53 cannot arrest and suffer relatively high levels of OA-mediated aberrant mitoses.

  15. Dynamic FoxG1 expression coordinates the integration of multipolar pyramidal neuron precursors into the cortical plate.

    PubMed

    Miyoshi, Goichi; Fishell, Gord

    2012-06-21

    Pyramidal cells of the cerebral cortex are born in the ventricular zone and migrate through the intermediate zone to enter into the cortical plate. In the intermediate zone, these migrating precursors move tangentially and initiate the extension of their axons by transiently adopting a characteristic multipolar morphology. We observe that expression of the forkhead transcription factor FoxG1 is dynamically regulated during this transitional period. By utilizing conditional genetic strategies, we show that the downregulation of FoxG1 at the beginning of the multipolar cell phase induces Unc5D expression, the timing of which ultimately determines the laminar identity of pyramidal neurons. In addition, we demonstrate that the re-expression of FoxG1 is required for cells to transit out of the multipolar cell phase and to enter into the cortical plate. Thus, the dynamic expression of FoxG1 during migration within the intermediate zone is essential for the proper assembly of the cerebral cortex.

  16. Structural and functional classes of multipolar cells in the ventral cochlear nucleus.

    PubMed

    Doucet, John R; Ryugo, David K

    2006-04-01

    Multipolar cells in the ventral cochlear nucleus (VCN) are a structurally and functionally diverse group of projection neurons. Understanding their role in the ascending pathway involves partitioning multipolar cells into distinct populations and determining where in the brain each sends its coded messages. In this study, we used retrograde labeling techniques in rats to identify multipolar neurons that project their axons to the ipsilateral dorsal cochlear nucleus (DCN), the contralateral CN, or both structures. Three rats received injections of biotinylated dextran amine in the ipsilateral DCN and diamidino yellow in the contralateral CN. Several radiate multipolar neurons (defined by their axonal projections to the ipsilateral DCN and their dendrites that traverse VCN isofrequency sheets) were double-labeled but over 70% were not. This result suggests two distinct populations: (1) radiate-commissural (RC) multipolar cells that project to the ipsilateral DCN and the contralateral CN, and (2) radiate multipolar cells that project exclusively (in this context) to the ipsilateral DCN. In a different group of animals, we retrogradely labeled multipolar neurons that project their axons to the contralateral CN and measured the size of their cell bodies. The mean size of this population (266 +/- 156 microm2) was significantly smaller than those of RC-multipolar cells (418 +/- 140 microm2). We conclude that the CN commissural pathway is composed of at least two components: (1) RC multipolar cells and (2) commissural multipolar cells that are small- and medium-sized neurons that project exclusively (in this context) to the contralateral CN. These results identify separate structural groups of multipolar cells that may correspond to physiological unit types described in the literature. They also provide protocols for isolating and studying different populations of multipolar cells to determine the neural mechanisms that govern their responses to sound.

  17. The Role of Angular Momentum in the Construction of Electromagnetic Multipolar Fields

    ERIC Educational Resources Information Center

    Tischler, Nora; Zambrana-Puyalto, Xavier; Molina-Terriza, Gabriel

    2012-01-01

    Multipolar solutions of Maxwell's equations are used in many practical applications and are essential for the understanding of light-matter interactions at the fundamental level. Unlike the set of plane wave solutions of electromagnetic fields, the multipolar solutions do not share a standard derivation or notation. As a result, expressions…

  18. Molecules and mechanisms that regulate multipolar migration in the intermediate zone.

    PubMed

    Cooper, Jonathan A

    2014-01-01

    Most neurons migrate with an elongated, "bipolar" morphology, extending a long leading process that explores the environment. However, when immature projection neurons enter the intermediate zone (IZ) of the neocortex they become "multipolar". Multipolar cells extend and retract cytoplasmic processes in different directions and move erratically-sideways, up and down. Multipolar cells extend axons while they are in the lower half of the IZ. Remarkably, the cells then resume radial migration: they reorient their centrosome and Golgi apparatus towards the pia, transform back to bipolar morphology, and commence locomotion along radial glia (RG) fibers. This reorientation implies the existence of directional signals in the IZ that are ignored during the multipolar stage but sensed after axonogenesis. In vivo genetic manipulation has implicated a variety of candidate directional signals, cell surface receptors, and signaling pathways, that may be involved in polarizing multipolar cells and stabilizing a pia-directed leading process for radial migration. Other signals are implicated in starting multipolar migration and triggering axon outgrowth. Here we review the molecules and mechanisms that regulate multipolar migration, and also discuss how multipolar migration affects the orderly arrangement of neurons in layers and columns in the developing neocortex.

  19. The body-centered cubic structure of methyllithium tetramer crystal: staggered methyl conformation by electrostatic stabilization via intratetramer multipolarization.

    PubMed

    Ohta, Yusuke; Demura, Akimitsu; Okamoto, Takuya; Hitomi, Haruko; Nagaoka, Masataka

    2006-06-29

    The methyllithium tetramer (CH3Li)4 structure in the bcc crystal has been theoretically optimized with the use of density functional theory calculations under the periodic boundary condition. The X-ray structure shows that the methyl-group conformation in tetramer in crystal takes the staggered form rather than the eclipsed form that is taken in the isolated tetramer, i.e., the crystal packing effect, and this has been reproduced for the first time. It is concluded that the staggered form is advantageous in crystal, as a whole, due to the larger electrostatic stabilization via the induced intratetramer multipolarization, although it should cause, simultaneously, smaller destabilization in intratetramer electronic energy.

  20. Anatomy of the Binary Black Hole Recoil: A Multipolar Analysis

    NASA Technical Reports Server (NTRS)

    Schnittman, Jeremy; Buonanno, Alessandra; vanMeter, James R.; Baker, John G.; Boggs, William D.; Centrella, Joan; Kelly, Bernard J.; McWilliams, Sean T.

    2007-01-01

    We present a multipolar analysis of the recoil velocity computed in recent numerical simulations of binary black hole coalescence, for both unequal masses and non-zero, non-precessing spins. We show that multipole moments up to and including 1 = 4 are sufficient to accurately reproduce the final recoil velocity (= 98%) and that only a few dominant modes contribute significantly to it (2 95%). We describe how the relative amplitude, and more importantly, the relative phase, of these few modes control the way in which the recoil builds up throughout the inspiral, merger, and ring-down phases. We also find that the numerical results can be reproduced, to a high level of accuracy, by an effective Newtonian formula for the multipole moments obtained by replacing in the Newtonian formula the radial separation with an effective radius computed from the numerical data. Beyond the merger, the numerical results are reproduced by a superposition of three Kerr quasi-normal modes. Analytic formulae, obtained by expressing the multipole moments in terms of the fundamental QNMs of a Kerr BH, are able to explain the onset and amount of '.anti-kick" for each of the simulations. Lastly, we apply this multipolar analysis to understand the remarkable difference between the amplitudes of planar and non-planar kicks for equal-mass spinning black holes.

  1. Transverse multipolar light-matter couplings in evanescent waves

    NASA Astrophysics Data System (ADS)

    Fernandez-Corbaton, Ivan; Zambrana-Puyalto, Xavier; Bonod, Nicolas; Rockstuhl, Carsten

    2016-11-01

    We present an approach to study the interaction between matter and evanescent fields. The approach is based on the decomposition of evanescent plane waves into multipoles of well-defined angular-momentum transverse to both decay and propagation directions. We use the approach to identify the origin of the recently observed directional coupling of emitters into guided modes, and of the opposite Zeeman state excitation of atoms near a fiber. We explain how to rigorously quantify both effects and show that the directionality and the difference in excitation rates grow exponentially with the multipolar order of the light-matter interaction. We also use the approach to study and maximize the transverse torque exerted by an evanescent plane wave onto a given spherical absorbing particle. All the obtained physical insights can be traced back to the two main features of the decomposition of evanescent plane waves into transverse multipolar modes: A polarization independent exponential dominance of modes with large transverse angular momentum, and a polarization-controlled parity selection rule.

  2. Molecules and mechanisms that regulate multipolar migration in the intermediate zone

    PubMed Central

    Cooper, Jonathan A.

    2014-01-01

    Most neurons migrate with an elongated, “bipolar” morphology, extending a long leading process that explores the environment. However, when immature projection neurons enter the intermediate zone (IZ) of the neocortex they become “multipolar”. Multipolar cells extend and retract cytoplasmic processes in different directions and move erratically—sideways, up and down. Multipolar cells extend axons while they are in the lower half of the IZ. Remarkably, the cells then resume radial migration: they reorient their centrosome and Golgi apparatus towards the pia, transform back to bipolar morphology, and commence locomotion along radial glia (RG) fibers. This reorientation implies the existence of directional signals in the IZ that are ignored during the multipolar stage but sensed after axonogenesis. In vivo genetic manipulation has implicated a variety of candidate directional signals, cell surface receptors, and signaling pathways, that may be involved in polarizing multipolar cells and stabilizing a pia-directed leading process for radial migration. Other signals are implicated in starting multipolar migration and triggering axon outgrowth. Here we review the molecules and mechanisms that regulate multipolar migration, and also discuss how multipolar migration affects the orderly arrangement of neurons in layers and columns in the developing neocortex. PMID:25452716

  3. Nanoscale interference patterns of gap-mode multipolar plasmonic fields.

    PubMed

    Tanaka, Yoshito; Sanada, Akio; Sasaki, Keiji

    2012-01-01

    Arbitrary spatial distributions of the electric field of light are formed through the interference of individual wavenumber mode fields with appropriate amplitudes and phases, while the maximum wavenumber in the far field is limited by the wavelength of light. In contrast, localized surface plasmons (LSPs) possess the ability to confine photons strongly into nanometer-scale areas, exceeding the diffraction limit. In particular, gap-mode LSPs produce single-nanometer-sized, highly intense localized fields, known as hot spots. Here, we show the nanoscale spatial profiles of the LSP fields within hot spots, which exhibit complicated fine structures, rather than single peaks. The nanopatterns are created by constructive and destructive interferences of dipolar, quadrupolar, and higher-order multipolar plasmonic modes, which can be drastically altered by controlling parameters of the excitation optical system. The analysis in this study would be useful for proposing new concepts for manipulation and control of light-matter interactions in nanospaces.

  4. Multipolar Coupling in Hybrid Metal–Dielectric Metasurfaces

    DOE PAGES

    Guo, Rui; Rusak, Evgenia; Staude, Isabelle; ...

    2016-03-02

    In this paper, we study functional hybrid metasurfaces consisting of metal–dielectric nanoantennas that direct light from an incident plane wave or from localized light sources into a preferential direction. The directionality is obtained by carefully balancing the multipolar contributions to the scattering response from the constituents of the metasurface. The hybrid nanoantennas are composed of a plasmonic gold nanorod acting as a feed element and a silicon nanodisk acting as a director element. In order to experimentally realize this design, we have developed a two-step electron-beam lithography process in combination with a precision alignment step. Finally, the optical response ofmore » the fabricated sample is measured and reveals distinct signatures of coupling between the plasmonic and the dielectric nanoantenna elements that ultimately leads to unidirectional radiation of light.« less

  5. Does Size Matter? The Multipolar International Landscape of Nanoscience

    PubMed Central

    Jensen, Pablo; Kreimer, Pablo

    2016-01-01

    How do different countries tackle nanoscience research? Are all countries similar except for a trivial size effect, as science is often assumed to be universal? Or does size dictate large differences, as large countries are able to develop activities in all directions of research, while small countries have to specialize in some specific niches? Alternatively, is size irrelevant, as all countries have followed different historical paths, leading to different patterns of specialisation? Here, we develop an original method that uses a bottom-up definition of scientific subfields to map the international structure of any scientific field. Our analysis shows that nanoscience research does not show a universal pattern of specialisation, homothetic of that of a single global leader (e.g., the United States). Instead, we find a multipolar world, with four main ways of doing nanosciences. PMID:27992439

  6. Multipolar interference for non-reciprocal nonlinear generation

    NASA Astrophysics Data System (ADS)

    Poutrina, Ekaterina; Urbas, Augustine

    2016-04-01

    We show that nonlinear multipolar interference allows achieving not only unidirectional, but also non-reciprocal nonlinear generation from a nanoelement, with the direction of the produced light decoupled from the direction of at least one of the excitation beams. Alternatively, it may allow inhibiting the specified nonlinear response in a nanoelement or in its periodic arrangement by reversing the direction of one of the pumps. These general phenomena exploit the fact that, contrary to the linear response case, nonlinear magneto-electric interference stems from a combination of additive and multiplicative processes and includes an interference between various terms within the electric and magnetic partial waves themselves. We demonstrate the introduced concept numerically using an example of a plasmonic dimer geometry with realistic material parameters.

  7. Multipolar Coupling in Hybrid Metal–Dielectric Metasurfaces

    SciTech Connect

    Guo, Rui; Rusak, Evgenia; Staude, Isabelle; Dominguez, Jason; Decker, Manuel; Rockstuhl, Carsten; Brener, Igal; Neshev, Dragomir N.; Kivshar, Yuri S.

    2016-03-02

    In this paper, we study functional hybrid metasurfaces consisting of metal–dielectric nanoantennas that direct light from an incident plane wave or from localized light sources into a preferential direction. The directionality is obtained by carefully balancing the multipolar contributions to the scattering response from the constituents of the metasurface. The hybrid nanoantennas are composed of a plasmonic gold nanorod acting as a feed element and a silicon nanodisk acting as a director element. In order to experimentally realize this design, we have developed a two-step electron-beam lithography process in combination with a precision alignment step. Finally, the optical response of the fabricated sample is measured and reveals distinct signatures of coupling between the plasmonic and the dielectric nanoantenna elements that ultimately leads to unidirectional radiation of light.

  8. Multipolar blackbody radiation shifts for single-ion clocks

    NASA Astrophysics Data System (ADS)

    Arora, Bindiya; Nandy, D. K.; Sahoo, B. K.

    2012-01-01

    Appraising the projected 10-18 fractional uncertainty in the optical frequency standards using singly ionized ions, we estimate the blackbody radiation (BBR) shifts due to the magnetic dipole (M1) and electric quadrupole (E2) multipoles of the applied external electromagnetic field. Multipolar scalar polarizabilities are determined for the singly ionized calcium (Ca+) and strontium (Sr+) ions using the relativistic coupled-cluster method, though the theory can be exercised for any single-ion clocks. The expected energy shifts for the respective clock transitions are estimated to be 4.38(3)×10-4 Hz for Ca+ and 9.50(7)×10-5 Hz for Sr+. These shifts are large enough and may be a prerequisite for the frequency standards to achieve the foreseen 10-18 precision goal.

  9. Multipolar interference for non-reciprocal nonlinear generation

    PubMed Central

    Poutrina, Ekaterina; Urbas, Augustine

    2016-01-01

    We show that nonlinear multipolar interference allows achieving not only unidirectional, but also non-reciprocal nonlinear generation from a nanoelement, with the direction of the produced light decoupled from the direction of at least one of the excitation beams. Alternatively, it may allow inhibiting the specified nonlinear response in a nanoelement or in its periodic arrangement by reversing the direction of one of the pumps. These general phenomena exploit the fact that, contrary to the linear response case, nonlinear magneto-electric interference stems from a combination of additive and multiplicative processes and includes an interference between various terms within the electric and magnetic partial waves themselves. We demonstrate the introduced concept numerically using an example of a plasmonic dimer geometry with realistic material parameters. PMID:27126209

  10. Does Size Matter? The Multipolar International Landscape of Nanoscience.

    PubMed

    Levin, Luciano; Jensen, Pablo; Kreimer, Pablo

    2016-01-01

    How do different countries tackle nanoscience research? Are all countries similar except for a trivial size effect, as science is often assumed to be universal? Or does size dictate large differences, as large countries are able to develop activities in all directions of research, while small countries have to specialize in some specific niches? Alternatively, is size irrelevant, as all countries have followed different historical paths, leading to different patterns of specialisation? Here, we develop an original method that uses a bottom-up definition of scientific subfields to map the international structure of any scientific field. Our analysis shows that nanoscience research does not show a universal pattern of specialisation, homothetic of that of a single global leader (e.g., the United States). Instead, we find a multipolar world, with four main ways of doing nanosciences.

  11. Incommensurate short-range multipolar order parameter of phase II in Ce3Pd20Si6

    NASA Astrophysics Data System (ADS)

    Portnichenko, P. Y.; Paschen, S.; Prokofiev, A.; Vojta, M.; Cameron, A. S.; Mignot, J.-M.; Ivanov, A.; Inosov, D. S.

    2016-12-01

    The clathrate compound Ce3Pd20Si6 is a heavy-fermion metal that exhibits magnetically hidden order at low temperatures. Reputedly, this exotic type of magnetic ground state, known as "phase II", could be associated with the ordering of Ce 4 f quadrupolar moments. In contrast to conventional (dipolar) order, it has vanishing Bragg intensity in zero magnetic field and, as a result, has escaped direct observation by neutron scattering until now. Here we report the observation of diffuse magnetic neutron scattering induced by an application of magnetic field along either the [1 1 ¯0 ] or the [001 ] direction within phase II. The broad elastic magnetic signal that surrounds the (111) structural Bragg peak can be attributed to a short-range G -type antiferromagnetic arrangement of field-induced dipoles modulated by the underlying multipolar order on the simple-cubic sublattice of Ce ions occupying the 8 c Wyckoff site. In addition, for magnetic fields applied along the [001 ] direction, the diffuse magnetic peaks in Ce3Pd20Si6 become incommensurate, suggesting a more complex modulated structure of the underlying multipolar order that can be continuously tuned by a magnetic field.

  12. Multipolar mitosis and aneuploidy after chrysotile treatment: a consequence of abscission failure and cytokinesis regression

    PubMed Central

    Cortez, Beatriz Araujo; Teixeira, Paula Rezende; Redick, Sambra; Doxsey, Stephen; Machado-Santelli, Glaucia Maria

    2016-01-01

    Chrysotile, like other types of asbestos, has been associated with mesothelioma, lung cancer and asbestosis. However, the cellular abnormalities induced by these fibers involved in cancer development have not been elucidated yet. Previous works show that chrysotile fibers induce features of cancer cells, such as aneuploidy, multinucleation and multipolar mitosis. In the present study, normal and cancer derived human cell lines were treated with chrysotile and the cellular and molecular mechanisms related to generation of aneuploid cells was elucidated. The first alteration observed was cytokinesis regression, the main cause of multinucleated cells formation and centrosome amplification. The multinucleated cells formed after cytokinesis regression were able to progress through cell cycle and generated aneuploid cells after abnormal mitosis. To understand the process of cytokinesis regression, localization of cytokinetic proteins was investigated. It was observed mislocalization of Anillin, Aurora B, Septin 9 and Alix in the intercellular bridge, and no determination of secondary constriction and abscission sites. Fiber treatment also led to overexpression of genes related to cancer, cytokinesis and cell cycle. The results show that chrysotile fibers induce cellular and molecular alterations in normal and tumor cells that have been related to cancer initiation and progression, and that tetraploidization and aneuploid cell formation are striking events after fiber internalization, which could generate a favorable context to cancer development. PMID:26788989

  13. Multipolar mitosis and aneuploidy after chrysotile treatment: a consequence of abscission failure and cytokinesis regression.

    PubMed

    Cortez, Beatriz Araujo; Rezende-Teixeira, Paula; Redick, Sambra; Doxsey, Stephen; Machado-Santelli, Glaucia Maria

    2016-02-23

    Chrysotile, like other types of asbestos, has been associated with mesothelioma, lung cancer and asbestosis. However, the cellular abnormalities induced by these fibers involved in cancer development have not been elucidated yet. Previous works show that chrysotile fibers induce features of cancer cells, such as aneuploidy, multinucleation and multipolar mitosis. In the present study, normal and cancer derived human cell lines were treated with chrysotile and the cellular and molecular mechanisms related to generation of aneuploid cells was elucidated. The first alteration observed was cytokinesis regression, the main cause of multinucleated cells formation and centrosome amplification. The multinucleated cells formed after cytokinesis regression were able to progress through cell cycle and generated aneuploid cells after abnormal mitosis. To understand the process of cytokinesis regression, localization of cytokinetic proteins was investigated. It was observed mislocalization of Anillin, Aurora B, Septin 9 and Alix in the intercellular bridge, and no determination of secondary constriction and abscission sites. Fiber treatment also led to overexpression of genes related to cancer, cytokinesis and cell cycle. The results show that chrysotile fibers induce cellular and molecular alterations in normal and tumor cells that have been related to cancer initiation and progression, and that tetraploidization and aneuploid cell formation are striking events after fiber internalization, which could generate a favorable context to cancer development.

  14. Prdm8 regulates the morphological transition at multipolar phase during neocortical development.

    PubMed

    Inoue, Mayuko; Kuroda, Takao; Honda, Aya; Komabayashi-Suzuki, Mariko; Komai, Tae; Shinkai, Yoichi; Mizutani, Ken-ichi

    2014-01-01

    Here, we found that the PR domain protein Prdm8 serves as a key regulator of the length of the multipolar phase by controlling the timing of morphological transition. We used a mouse line with expression of Prdm8-mVenus reporter and found that Prdm8 is predominantly expressed in the middle and upper intermediate zone during both the late and terminal multipolar phases. Prdm8 expression was almost coincident with Unc5D expression, a marker for the late multipolar phase, although the expression of Unc5D was found to be gradually down-regulated to the point at which mVenus expression was gradually up-regulated. This expression pattern suggests the possible involvement of Prdm8 in the control of the late and terminal multipolar phases, which controls the timing for morphological transition. To test this hypothesis, we performed gain- and loss-of-function analysis of neocortical development by using in utero electroporation. We found that the knockdown of Prdm8 results in premature change from multipolar to bipolar morphology, whereas the overexpression of Prdm8 maintained the multipolar morphology. Additionally, the postnatal analysis showed that the Prdm8 knockdown stimulated the number of early born neurons, and differentiated neurons located more deeply in the neocortex, however, majority of those cells could not acquire molecular features consistent with laminar location. Furthermore, we found the candidate genes that were predominantly utilized in both the late and terminal multipolar phases, and these candidate genes included those encoding for guidance molecules. In addition, we also found that the expression level of these guidance molecules was inhibited by the introduction of the Prdm8 expression vector. These results indicate that the Prdm8-mediated regulation of morphological changes that normally occur during the late and terminal multipolar phases plays an important role in neocortical development.

  15. Multipolar migration: the third mode of radial neuronal migration in the developing cerebral cortex.

    PubMed

    Tabata, Hidenori; Nakajima, Kazunori

    2003-11-05

    Two distinct modes of radial neuronal migration, locomotion and somal translocation, have been reported in the developing cerebral cortex. Although these two modes of migration have been well documented, the cortical intermediate zone contains abundant multipolar cells, and they do not resemble the cells migrating by locomotion or somal translocation. Here, we report that these multipolar cells express neuronal markers and extend multiple thin processes in various directions independently of the radial glial fibers. Time-lapse analysis of living slices revealed that the multipolar cells do not have any fixed cell polarity, and that they very dynamically extend and retract multiple processes as their cell bodies slowly move. They do not usually move straight toward the pial surface during their radial migration, but instead frequently change migration direction and rate; sometimes they even remain in almost the same position, especially when they are in the subventricular zone. Occasionally, the multipolar cells jump tangentially during their radial migration. Because the migration modality of these cells clearly differs from locomotion or somal translocation, we refer to their novel type of migration as "multipolar migration." In view of the high proportion of cells exhibiting multipolar migration, this third mode of radial migration must be an important type of migration in the developing cortex.

  16. A Global Optimization Approach to Multi-Polarity Sentiment Analysis

    PubMed Central

    Li, Xinmiao; Li, Jing; Wu, Yukeng

    2015-01-01

    Following the rapid development of social media, sentiment analysis has become an important social media mining technique. The performance of automatic sentiment analysis primarily depends on feature selection and sentiment classification. While information gain (IG) and support vector machines (SVM) are two important techniques, few studies have optimized both approaches in sentiment analysis. The effectiveness of applying a global optimization approach to sentiment analysis remains unclear. We propose a global optimization-based sentiment analysis (PSOGO-Senti) approach to improve sentiment analysis with IG for feature selection and SVM as the learning engine. The PSOGO-Senti approach utilizes a particle swarm optimization algorithm to obtain a global optimal combination of feature dimensions and parameters in the SVM. We evaluate the PSOGO-Senti model on two datasets from different fields. The experimental results showed that the PSOGO-Senti model can improve binary and multi-polarity Chinese sentiment analysis. We compared the optimal feature subset selected by PSOGO-Senti with the features in the sentiment dictionary. The results of this comparison indicated that PSOGO-Senti can effectively remove redundant and noisy features and can select a domain-specific feature subset with a higher-explanatory power for a particular sentiment analysis task. The experimental results showed that the PSOGO-Senti approach is effective and robust for sentiment analysis tasks in different domains. By comparing the improvements of two-polarity, three-polarity and five-polarity sentiment analysis results, we found that the five-polarity sentiment analysis delivered the largest improvement. The improvement of the two-polarity sentiment analysis was the smallest. We conclude that the PSOGO-Senti achieves higher improvement for a more complicated sentiment analysis task. We also compared the results of PSOGO-Senti with those of the genetic algorithm (GA) and grid search method. From

  17. Induction of robust de novo centrosome amplification, high-grade spindle multipolarity and metaphase catastrophe: a novel chemotherapeutic approach.

    PubMed

    Pannu, V; Rida, P C G; Ogden, A; Clewley, R; Cheng, A; Karna, P; Lopus, M; Mishra, R C; Zhou, J; Aneja, R

    2012-07-12

    Centrosome amplification (CA) and resultant chromosomal instability have long been associated with tumorigenesis. However, exacerbation of CA and relentless centrosome declustering engender robust spindle multipolarity (SM) during mitosis and may induce cell death. Recently, we demonstrated that a noscapinoid member, reduced bromonoscapine, (S)-3-(R)-9-bromo-5-(4,5-dimethoxy-1,3-dihydroisobenzofuran-1-yl)-4-methoxy-6-methyl-5,6,7,8-tetrahydro-[1,3]dioxolo-[4,5-g]isoquinoline (Red-Br-nos), induces reactive oxygen species (ROS)-mediated autophagy and caspase-independent death in prostate cancer PC-3 cells. Herein, we show that Red-Br-nos induces ROS-dependent DNA damage that resulted in high-grade CA and SM in PC-3 cells. Unlike doxorubicin, which causes double-stranded DNA breaks and chronic G2 arrest accompanied by 'templated' CA, Red-Br-nos-mediated DNA damage elicits de novo CA during a transient S/G2 stall, followed by checkpoint abrogation and mitotic entry to form aberrant mitotic figures with supernumerary spindle poles. Attenuation of multipolar phenotype in the presence of tiron, a ROS inhibitor, indicated that ROS-mediated DNA damage was partly responsible for driving CA and SM. Although a few cells (∼5%) yielded to aberrant cytokinesis following an 'anaphase catastrophe', most mitotically arrested cells (∼70%) succumbed to 'metaphase catastrophe,' which was caspase-independent. This report is the first documentation of rapid de novo centrosome formation in the presence of parent centrosome by a noscapinoid family member, which triggers death-inducing SM via a unique mechanism that distinguishes it from other ROS-inducers, conventional DNA-damaging agents, as well as other microtubule-binding drugs.

  18. Ordering in linear multipolar colloids driven by an external field.

    PubMed

    Alarcón-Waess, O

    2006-08-14

    An approach to describe a linear multipolar colloid driven by an external field is developed by considering a colloid which in absence of the field is low structured and its coupling potential is axially symmetric. The equilibrium correlation of one component of the orientation tensor, self and collective, is computed up to linear order in density, which can be measured in an appropriate light scattering experiment. The self-correlation is written in terms of the second and fourth order parameters. All the equilibrium quantities are computed up to two-body level. This is done by assuming that the two-body equilibrium density function is given by the Boltzmann distribution, whereas the one-body density function is computed as solution of the equilibrium N-body Smoluchowski equation in the absence of hydrodynamic interactions. These observables, self and collective, as well as the second and fourth order parameters are able to describe when the colloid would evolve to an orientationally ordered phase. Explicit results for the dipole and quadrupole moments are reported. These results predict a different alignment with the external field for each moment. A relationship is provided between second and fourth order parameters, predicting the critical value of the external field in which the colloid goes into an axially symmetric phase.

  19. Configuration analysis and optimization on multipolar Galatea trap

    NASA Astrophysics Data System (ADS)

    Tong, W. M.; Tao, B. Q.; Jin, X. J.; Li, Z. W.

    2016-10-01

    Multipolar Galatea magnetic trap simulation model was established with the finite element simulation software COMSOL Multiphysics. Analyses about the magnetic section configuration show that better magnetic configuration should make more plasma stay in the weak magnetic field rather than the annular magnetic shell field. Then an optimization model was established with axial electromagnetic force, weak magnetic field area and average magnetic mirror ratio as the optimization goals and with the currents of myxines as design variables. Select appropriate weight coefficients and get optimization results by applying genetic algorithm. Results show that the superiority of the target value of typical application parameters, including the average magnetic mirror can reduce more than 5%, the weak magnetic field area can increase at least 65%, at the same time, axial electromagnetic force acting on the outer myxines can be reduced to less than 50 N. Finally, the results were proved by COMSOL Multiphysics and the results proved the optimized magnetic trap configuration with more plasma in the weak magnetic field can reduce the plasma diffusion velocity and is more conducive for the constraint of plasma.

  20. A multipolar approach to the interatomic covalent interaction energy.

    PubMed

    Francisco, Evelio; Menéndez Crespo, Daniel; Costales, Aurora; Martín Pendás, Ángel

    2017-04-30

    Interatomic exchange-correlation energies correspond to the covalent energetic contributions to an interatomic interaction in real space theories of the chemical bond, but their widespread use is severely limited due to their computationally intensive character. In the same way as the multipolar (mp) expansion is customary used in biomolecular modeling to approximate the classical Coulomb interaction between two charge densities ρA(r) and ρB(r), we examine in this work the mp approach to approximate the interatomic exchange-correlation (xc) energies of the Interacting Quantum Atoms method. We show that the full xc mp series is quickly divergent for directly bonded atoms (1-2 pairs) albeit it works reasonably well most times for 1- n (n > 2) interactions. As with conventional perturbation theory, we show numerically that the xc series is asymptotically convergent and that, a truncated xc mp approximation retaining terms up to l1+l2=2 usually gives relatively accurate results, sometimes even for directly bonded atoms. Our findings are supported by extensive numerical analyses on a variety of systems that range from several standard hydrogen bonded dimers to typically covalent or aromatic molecules. The exact algebraic relationship between the monopole-monopole xc mp term and the inter-atomic bond order, as measured by the delocalization index of the quantum theory of atoms in molecules, is also established. © 2017 Wiley Periodicals, Inc.

  1. Multipolar correlations between reactants in crystalline and semiamorphous zeolites

    SciTech Connect

    Mandeville, J.B.; Golub, J.; Kozak, J.J.

    1988-03-24

    The authors study the role of multipolar correlations in influencing the efficiency of reaction between a fixed target molecule and a diffusing coreactant in zeolites that exhibit both crystalline and semiamorphous structures. They focus on zeolite A and construct a geometrical model whose framework structure and attendant channel patterns have the same topology as the 26-hedral cavities of type I of this aluminosilicate. They consider reaction partners interacting via (attractiverepulsive) ion-ion, angle-averaged ion-dipole, and angle-averaged dipole-dipole potentials V(r), and by coupling the theory of finite Markov processes with a lattice version of the Debye-Smoluchowski theory of encounter-controlled reactions, they quantify the differences in the diffusion-controlled rate constant k/sub D/ for reactions taking place in crystalline regions of finite extent (rafts) versus those occurring in crystalline regions surrounded by an amorphous aluminosilicate structure. Calculations based on the model introduced in this paper suggest that much of the marked cation-exchange activity and catalytic activity of fully crystalline zeolites is already captured by semiamorphous zeolites containing raft structures having the spatial extent of those found in recent experimental work by Thomas and Bursill

  2. Two-site fluctuations and multipolar intersite exchange interactions in strongly correlated systems

    NASA Astrophysics Data System (ADS)

    Pourovskii, L. V.

    2016-09-01

    An approach is proposed for evaluating dipolar and multipolar intersite interactions in strongly correlated materials. This approach is based on the single-site dynamical mean-field theory (DMFT) in conjunction with the atomic approximation for the local self-energy. Starting from the local-moment paramagnetic state described by DMFT, we derive intersite interactions by considering the response of the DMFT grand potential to small fluctuations of atomic configurations on two neighboring sites. The present method is validated by applying it to one-band and two-band eg Hubbard models on the simple-cubic 3 d lattice. It is also applied to study the spin-orbital order in the parent cubic structure of ternary chromium fluoride KCrF3. We obtain the onset of a G-type antiferro-orbital order at a significantly lower temperature compared to that in real distorted KCrF3. In contrast, its layered A-type antiferromagnetic order and Néel temperature are rather well reproduced. The calculated full Kugel-Khomskii Hamiltonian contains spin-orbital coupling terms inducing a misalignment in the antiferro-orbital order upon the onset of antiferromagnetism.

  3. Exposure of Allium cepa root cells to zidovudine or nevirapine induces cytogenotoxic changes.

    PubMed

    Onwuamah, Chika K; Ekama, Sabdat O; Audu, Rosemary A; Ezechi, Oliver C; Poirier, Miriam C; Odeigah, Peter G C

    2014-01-01

    Antiretroviral drugs have proved useful in the clinical management of HIV-infected persons, though there are concerns about the effects of exposure to these DNA-reactive drugs. We investigated the potential of the plant model Allium cepa root tip assay to demonstrate the cytogenotoxicity of zidovudine and nevirapine and as a replace-reduce-refine programme amenable to resource-poor research settings. Cells mitotic index were determined in squashed root cells from Allium cepa bulbs exposed to zidovudine or nevirapine for 48 hr. The concentration of zidovudine and nevirapine inhibiting 50% root growth after 96 hr exposure was 65.0 µM and 92.5 µM respectively. Root length of all antiretroviral-exposed roots after 96 hr exposure was significantly shorter than the unexposed roots while additional root growth during a subsequent 48 hr recovery period in the absence of drug was not significantly different. By ANOVA, there was a significant association between percentage of cells in mitosis and zidovudine dose (p=0.004), but not nevirapine dose (p=0.68). Chromosomal aberrations such as sticky chromosomes, chromatin bridges, multipolar mitoses and binucleated cells were observed in root cells exposed to zidovudine and nevirapine for 48 hr. The most notable chromosomal aberration was drug-related increases in sticky chromosomes. Overall, the study showed inhibition in root length growth, changes in the mitotic index, and the induction of chromosomal aberrations in Allium bulbs treated for 96 hr or 48 hr with zidovudine and nevirapine. The study reveals generalized cytogenotoxic damage induced by exposure to zidovudine and nevirapine, and further show that the two compounds differ in their effects on mitosis and the types of chromosomal aberrations induced.

  4. Exposure of Allium cepa Root Cells to Zidovudine or Nevirapine Induces Cytogenotoxic Changes

    PubMed Central

    Onwuamah, Chika K.; Ekama, Sabdat O.; Audu, Rosemary A.; Ezechi, Oliver C.; Poirier, Miriam C.; Odeigah, Peter G C.

    2014-01-01

    Antiretroviral drugs have proved useful in the clinical management of HIV-infected persons, though there are concerns about the effects of exposure to these DNA-reactive drugs. We investigated the potential of the plant model Allium cepa root tip assay to demonstrate the cytogenotoxicity of zidovudine and nevirapine and as a replace-reduce-refine programme amenable to resource–poor research settings. Cells mitotic index were determined in squashed root cells from Allium cepa bulbs exposed to zidovudine or nevirapine for 48 hr. The concentration of zidovudine and nevirapine inhibiting 50% root growth after 96 hr exposure was 65.0 µM and 92.5 µM respectively. Root length of all antiretroviral-exposed roots after 96 hr exposure was significantly shorter than the unexposed roots while additional root growth during a subsequent 48 hr recovery period in the absence of drug was not significantly different. By ANOVA, there was a significant association between percentage of cells in mitosis and zidovudine dose (p = 0.004), but not nevirapine dose (p = 0.68). Chromosomal aberrations such as sticky chromosomes, chromatin bridges, multipolar mitoses and binucleated cells were observed in root cells exposed to zidovudine and nevirapine for 48 hr. The most notable chromosomal aberration was drug-related increases in sticky chromosomes. Overall, the study showed inhibition in root length growth, changes in the mitotic index, and the induction of chromosomal aberrations in Allium bulbs treated for 96 hr or 48 hr with zidovudine and nevirapine. The study reveals generalized cytogenotoxic damage induced by exposure to zidovudine and nevirapine, and further show that the two compounds differ in their effects on mitosis and the types of chromosomal aberrations induced. PMID:24599327

  5. Multi-Polarization Reconfigurable Antenna for Wireless Biomedical System.

    PubMed

    Wong, Hang; Lin, Wei; Huitema, Laure; Arnaud, Eric

    2017-01-23

    This paper presents a multi-polarization reconfigurable antenna with four dipole radiators for biomedical applications in body-centric wireless communication system (BWCS). The proposed multi-dipole antenna with switchable 0°, +45°, 90° and -45° linear polarizations is able to overcome the polarization mismatching and multi-path distortion in complex wireless channels as in BWCS. To realize this reconfigurable feature for the first time among all the reported antenna designs, we assembled four dipoles together with 45° rotated sequential arrangements. These dipoles are excited by the same feeding source provided by a ground tapered Balun. A metallic reflector is placed below the dipoles to generate a broadside radiation. By introducing eight PIN diodes as RF switches between the excitation source and the four dipoles, we can control a specific dipole to operate. As the results, 0°, +45°, 90° and -45° linear polarizations can be switched correspondingly to different operating dipoles. Experimental results agree with the simulation and show that the proposed antenna well works in all polarization modes with desirable electrical characteristics. The antenna has a wide impedance bandwidth of 34% from 2.2 to 3.1 GHz (for the reflection coefficient ≤ -10 dB) and exhibits a stable cardioid-shaped radiation pattern across the operating bandwidth with a peak gain of 5.2 dBi. To validate the effectiveness of the multi-dipole antenna for biomedical applications, we also designed a meandered PIFA as the implantable antenna. Finally, the communication link measurement shows that our proposed antenna is able to minimize the polarization mismatching and maintains the optimal communication link thanks to its polarization reconfigurability.

  6. Electrophysiological channel interactions using focused multipolar stimulation for cochlear implants

    NASA Astrophysics Data System (ADS)

    George, Shefin S.; Shivdasani, Mohit N.; Wise, Andrew K.; Shepherd, Robert K.; Fallon, James B.

    2015-12-01

    Objective. Speech intelligibility with existing multichannel cochlear implants (CIs) is thought to be limited by poor spatial selectivity and interactions between CI channels caused by overlapping activation with monopolar (MP) stimulation. Our previous studies have shown that focused multipolar (FMP) and tripolar (TP) stimulation produce more restricted neural activation in the inferior colliculus (IC), compared to MP stimulation. Approach. This study explored interactions in the IC produced by simultaneous stimulation of two CI channels. We recorded multi-unit neural activity in the IC of anaesthetized cats with normal and severely degenerated spiral ganglion neuron populations in response to FMP, TP and MP stimulation from a 14 channel CI. Stimuli were applied to a ‘fixed’ CI channel, chosen toward the middle of the cochlear electrode array, and the effects of simultaneously stimulating a more apical ‘test’ CI channel were measured as a function of spatial separation between the two stimulation channels and stimulus level of the fixed channel. Channel interactions were quantified by changes in neural responses and IC threshold (i.e., threshold shift) elicited by simultaneous stimulation of two CI channels, compared to stimulation of the test channel alone. Main results. Channel interactions were significantly lower for FMP and TP than for MP stimulation (p < 0.001), whereas no significant difference was observed between FMP and TP stimulation. With MP stimulation, threshold shifts increased with decreased inter-electrode spacing and increased stimulus levels of the fixed channel. For FMP and TP stimulation, channel interactions were found to be similar for different inter-electrode spacing and stimulus levels of the fixed channel. Significance. The present study demonstrates how the degree of channel interactions in a CI can be controlled using stimulation configurations such as FMP and TP; such knowledge is essential in enhancing CI function in complex

  7. Numerical simulation of multipolar configuration and prepulse technique to obtain spatially reverse recruitment order.

    PubMed

    Dali, Melissa; Rossel, Olivier; Guiraud, David

    2016-08-01

    In the context of functional electrical stimulation of peripheral nerves, the control of a specific motor or sensory functions may need selective stimulation to target the desired effect without others. In implanted stimulation, spatial selectivity is obtained using multipolar CUFF electrodes with specific spread of the current over each contact. Furthermore, electrical stimulation recruits large fibers before small ones, whereas the targeted function could be elicited by a specific fiber type i.e. fiber diameter. In our work, numerical simulations were used to investigate the combination of multipolar configuration and prepulses, in order to obtain spatially reverse recruitment order. Multipolar stimulation provides efficient spatial selectivity, whereas sub-threshold prepulses were used to reverse recruitment order with a reasonable increase of the injected charges. We compared several selective configurations combined with prepulses to show that some are able to guarantee both the spatial selectivity while one fiber's diameter can be preferentially activated.

  8. Planar multipolar cells in the cochlear nucleus project to medial olivocochlear neurons in mouse.

    PubMed

    Darrow, Keith N; Benson, Thane E; Brown, M Christian

    2012-05-01

    Medial olivocochlear (MOC) neurons originate in the superior olivary complex and project to the cochlea, where they act to reduce the effects of noise masking and protect the cochlea from damage. MOC neurons respond to sound via a reflex pathway; however, in this pathway the cochlear nucleus cell type that provides input to MOC neurons is not known. We investigated whether multipolar cells of the ventral cochlear nucleus have projections to MOC neurons by labeling them with injections into the dorsal cochlear nucleus. The projections of one type of labeled multipolar cell, planar neurons, were traced into the ventral nucleus of the trapezoid body, where they were observed terminating on MOC neurons (labeled in some cases by a second cochlear injection of FluoroGold). These terminations formed what appear to be excitatory synapses, i.e., containing small, round vesicles and prominent postsynaptic densities. These data suggest that cochlear nucleus planar multipolar neurons drive the MOC neuron's response to sound.

  9. Short-Term Results of Laparoscopic Radiofrequency Ablation Using a Multipolar System for Localized Hepatocellular Carcinoma

    PubMed Central

    Morimoto, Naoki; Isoda, Norio; Takaoka, Yoshinari; Hirosawa, Takuya; Watanabe, Shunji; Otake, Toshiya; Murayama, Kozue; Fujieda, Takeshi; Tsukui, Mamiko; Miyata, Natsumi; Ono, Kohei; Yamaguchi, Shota; Yamamoto, Hironori

    2017-01-01

    Background and Aim Multipolar radiofrequency ablation (RFA) is feasible for the treatment of hepatocellular carcinoma (HCC) for which a large ablative area is planned, and it imposes a light physical burden on patients. Multipolar RFA via the percutaneous approach is performed in the majority of cases, but the efficacy of multipolar RFA with a laparoscopic approach has rarely been studied. This study aimed to evaluate the efficacy and safety of multipolar laparoscopic RFA (LRA) for localized HCC over the short term. Methods From January 2014 to January 2016, 77 consecutive patients with 130 HCCs treated by multipolar LRA were assessed. One to three bipolar needle applicators were inserted under laparoscopic ultrasonography guidance, regardless of tumor location. We intended to achieve parallel insertions and no-touch ablation as much as possible. Results The median size of the main tumor was 22 mm (range, 10-42 mm). The median follow-up time was 13.6 months (range, 3.1-24.8 months). In all cases, a sufficient ablative area was obtained as planned, without thermal injury of adjacent organs. During the follow-up period, all patients were alive with no local tumor progression, while intrahepatic recurrence distant from the primary site occurred in 7 patients. The 2-year local tumor progression-free survival rate and overall cancer-free survival rate were 100 and 81.6%, respectively. There were no procedural major complications caused prolonging the hospitalization, and all patients were discharged without subjective symptoms 4-7 days after LRA. Conclusions Multipolar LRA was efficacious in the treatment of localized HCCs by safely achieving a good ablative area. PMID:28275580

  10. Connexin 43 controls the multipolar phase of neuronal migration to the cerebral cortex.

    PubMed

    Liu, Xiuxin; Sun, Lin; Torii, Masaaki; Rakic, Pasko

    2012-05-22

    The prospective pyramidal neurons, migrating from the proliferative ventricular zone to the overlaying cortical plate, assume multipolar morphology while passing through the transient subventricular zone. Here, we show that this morphogenetic transformation, from the bipolar to the mutipolar and then back to bipolar again, is associated with expression of connexin 43 (Cx43) and, that knockdown of Cx43 retards, whereas its overexpression enhances, this morphogenetic process. In addition, we have observed that knockdown of Cx43 reduces expression of p27, whereas overexpression of p27 rescues the effect of Cx43 knockdown in the multipolar neurons. Furthermore, functional gap junction/hemichannel domain, and the C-terminal domain of Cx43, independently enhance the expression of p27 and promote the morphological transformation and migration of the multipolar neurons in the SVZ/IZ. Collectively, these results indicate that Cx43 regulates the passage of migrating neurons through their multipolar stage via p27 signaling and that interference with this process, by either genetic and/or environmental factors, may cause cortical malformations.

  11. Spherical tensor multipolar electrostatics and smooth particle mesh Ewald summation: a theoretical study.

    PubMed

    Zielinski, François; Popelier, Paul L A

    2014-07-01

    The point-charge approximation, typically used by classical molecular mechanics force-fields, can be overcome by a multipolar expansion. For decades multipole moments were only used in the context of the rigid body approximation but recently it has become possible to combine multipolar electrostatics with molecular flexibility. The program DL_MULTI, which is derived from DL_POLY_2, includes efficient multipolar Ewald functionality up to the hexadecapole moment but the code is restricted to rigid bodies. The incorporation of flexibility into DL_MULTI would cause too large an impact on its architecture whereas the package DL_POLY_4 offers a more attractive and sustainable route to handle multipolar electrostatics. This package inherently handles molecular flexibility, which warrants sufficiently transferable atoms or atoms that are "knowledgeable" about their chemical environment (as made possible by quantum chemical topology and machine learning). DL_MULTI uses the spherical multipole formalism, which is mathematically more involved than the Cartesian one but which is more compact. DL_POLY_4 uses the computationally efficient method of smooth particle mesh Ewald (SPME) summation, which has also been parallellized by others. Therefore, combining the strengths of DL_POLY_4 and DL_MULTI poses the challenge of merging SPME with multipolar electrostatics by spherical multipole. In an effort to recast as clearly as possible the principles behind DL_MULTI, its key equations have been reformulated by the more streamlined route involving the algebra of complex numbers, and some of these equations' peculiarities clarified. This article explores theoretically the repercussions of the merging of SPME with spherical multipole electrostatics (as implemented in DL_MULTI). Difficulties in design and implementation of possible future code are discussed.

  12. Hubble space telescope observations and geometric models of compact multipolar planetary nebulae

    SciTech Connect

    Hsia, Chih-Hao; Chau, Wayne; Zhang, Yong; Kwok, Sun E-mail: wwlljj1314@gmail.com E-mail: sunkwok@hku.hk

    2014-05-20

    We report high angular resolution Hubble Space Telescope observations of 10 compact planetary nebulae (PNs). Many interesting internal structures, including multipolar lobes, arcs, two-dimensional rings, tori, and halos, are revealed for the first time. These results suggest that multipolar structures are common among PNs, and these structures develop early in their evolution. From three-dimensional geometric models, we have determined the intrinsic dimensions of the lobes. Assuming the lobes are the result of interactions between later-developed fast winds and previously ejected asymptotic giant branch winds, the geometric structures of these PNs suggest that there are multiple phases of fast winds separated by temporal variations and/or directional changes. A scenario of evolution from lobe-dominated to cavity-dominated stages is presented. The results reported here will provide serious constraints on any dynamical models of PNs.

  13. Wnt signaling regulates multipolar-to-bipolar transition of migrating neurons in the cerebral cortex.

    PubMed

    Boitard, Michael; Bocchi, Riccardo; Egervari, Kristof; Petrenko, Volodymyr; Viale, Beatrice; Gremaud, Stéphane; Zgraggen, Eloisa; Salmon, Patrick; Kiss, Jozsef Z

    2015-03-03

    The precise timing of pyramidal cell migration from the ventricular germinal zone to the cortical plate is essential for establishing cortical layers, and migration errors can lead to neurodevelopmental disorders underlying psychiatric and neurological diseases. Here, we report that Wnt canonical as well as non-canonical signaling is active in pyramidal precursors during radial migration. We demonstrate using constitutive and conditional genetic strategies that transient downregulation of canonical Wnt/β-catenin signaling during the multipolar stage plays a critical role in polarizing and orienting cells for radial migration. In addition, we show that reduced canonical Wnt signaling is triggered cell autonomously by time-dependent expression of Wnt5A and activation of non-canonical signaling. We identify ephrin-B1 as a canonical Wnt-signaling-regulated target in control of the multipolar-to-bipolar switch. These findings highlight the critical role of Wnt signaling activity in neuronal positioning during cortical development.

  14. Magnetar giant flares in multipolar magnetic fields. I. Fully and partially open eruptions of flux ropes

    SciTech Connect

    Huang, Lei; Yu, Cong E-mail: cyu@ynao.ac.cn

    2014-04-01

    We propose a catastrophic eruption model for the enormous energy release of magnetars during giant flares, in which a toroidal and helically twisted flux rope is embedded within a force-free magnetosphere. The flux rope stays in stable equilibrium states initially and evolves quasi-statically. Upon the loss of equilibrium, the flux rope cannot sustain the stable equilibrium states and erupts catastrophically. During the process, the magnetic energy stored in the magnetosphere is rapidly released as the result of destabilization of global magnetic topology. The magnetospheric energy that could be accumulated is of vital importance for the outbursts of magnetars. We carefully establish the fully open fields and partially open fields for various boundary conditions at the magnetar surface and study the relevant energy thresholds. By investigating the magnetic energy accumulated at the critical catastrophic point, we find that it is possible to drive fully open eruptions for dipole-dominated background fields. Nevertheless, it is hard to generate fully open magnetic eruptions for multipolar background fields. Given the observational importance of the multipolar magnetic fields in the vicinity of the magnetar surface, it would be worthwhile to explore the possibility of the alternative eruption approach in multipolar background fields. Fortunately, we find that flux ropes may give rise to partially open eruptions in the multipolar fields, which involve only partial opening of background fields. The energy release fractions are greater for cases with central-arcaded multipoles than those with central-caved multipoles that emerged in background fields. Eruptions would fail only when the centrally caved multipoles become extremely strong.

  15. RP58 regulates the multipolar-bipolar transition of newborn neurons in the developing cerebral cortex.

    PubMed

    Ohtaka-Maruyama, Chiaki; Hirai, Shinobu; Miwa, Akiko; Heng, Julian Ik-Tsen; Shitara, Hiroshi; Ishii, Rie; Taya, Choji; Kawano, Hitoshi; Kasai, Masataka; Nakajima, Kazunori; Okado, Haruo

    2013-02-21

    Accumulating evidence suggests that many brain diseases are associated with defects in neuronal migration, suggesting that this step of neurogenesis is critical for brain organization. However, the molecular mechanisms underlying neuronal migration remain largely unknown. Here, we identified the zinc-finger transcriptional repressor RP58 as a key regulator of neuronal migration via multipolar-to-bipolar transition. RP58(-/-) neurons exhibited severe defects in the formation of leading processes and never shifted to the locomotion mode. Cre-mediated deletion of RP58 using in utero electroporation in RP58(flox/flox) mice revealed that RP58 functions in cell-autonomous multipolar-to-bipolar transition, independent of cell-cycle exit. Finally, we found that RP58 represses Ngn2 transcription to regulate the Ngn2-Rnd2 pathway; Ngn2 knockdown rescued migration defects of the RP58(-/-) neurons. Our findings highlight the critical role of RP58 in multipolar-to-bipolar transition via suppression of the Ngn2-Rnd2 pathway in the developing cerebral cortex.

  16. Phosphorylation of SCG10/stathmin-2 determines multipolar stage exit and neuronal migration rate.

    PubMed

    Westerlund, Nina; Zdrojewska, Justyna; Padzik, Artur; Komulainen, Emilia; Björkblom, Benny; Rannikko, Emmy; Tararuk, Tanya; Garcia-Frigola, Cristina; Sandholm, Jouko; Nguyen, Laurent; Kallunki, Tuula; Courtney, Michael J; Coffey, Eleanor T

    2011-03-01

    Cell migration is the consequence of the sum of positive and negative regulatory mechanisms. Although appropriate migration of neurons is a principal feature of brain development, the negative regulatory mechanisms remain obscure. We found that JNK1 was highly active in developing cortex and that selective inhibition of JNK in the cytoplasm markedly increased both the frequency of exit from the multipolar stage and radial migration rate and ultimately led to an ill-defined cellular organization. Moreover, regulation of multipolar-stage exit and radial migration in Jnk1(-/-) (also known as Mapk8) mice, resulted from consequential changes in phosphorylation of the microtubule regulator SCG10 (also called stathmin-2). Expression of an SCG10 mutant that mimics the JNK1-phosphorylated form restored normal migration in the brains of Jnk1(-/-) mouse embryos. These findings indicate that the phosphorylation of SCG10 by JNK1 is a fundamental mechanism that governs the transition from the multipolar stage and the rate of neuronal cell movement during cortical development.

  17. Force-balance model of suppression of multipolar division in cancer cells with extra centrosomes

    NASA Astrophysics Data System (ADS)

    Zhu, Jie

    2013-03-01

    Cancer cells often possess extra centrosomes which have the potential to cause cell death due to catastrophic multipolar division. Many cancer cells, however, are able to escape multipolar mitosis by clustering the extra centrosomes to form bipolar spindles. The mechanism of centrosome clustering is therefore of great interest to the development of anti-cancer drugs because the de-clustering of extra centrosomes provides an appealing way to eliminate cancer cells while keeping healthy cells intact. We present a physical model assuming 1) dynamic centrosomal microtubules interact with chromosomes by both pushing on chromosome arms and pulling along kinetochores; 2) these microtubules interact with force generators associated with actin/adhesion structures at the cell boundary; and 3) motors act on anti-parallel microtubules from different centrosomes. We find via computer simulations that chromosomes tend to aggregate near the cell center while centrosomes can be either clustered to form bipolar spindles or scattered to form multipolar spindles, depending on the strengths of relative forces, cell shape and adhesion geometry. The model predictions agree with data from cells plated on adhesive micropatterns and from biochemically or genetically perturbed cells. Furthermore, our model is able to explain various microtubule distributions in interphase cells on patterned substrates. This work was supported by NSF

  18. Effects of multipolar electrode radiofrequency energy delivery on ventricular endocardium

    SciTech Connect

    Oeff, M.; Langberg, J.J.; Franklin, J.O.; Chin, M.C.; Sharkey, H.; Finkbeiner, W.; Herre, J.M.; Scheinman, M.M. )

    1990-03-01

    This study examined the effects of radiofrequency energy applied in a bipolar fashion with single as compared with multiple sequential applications at the canine endocardium. In this closed-chest model, radiofrequency energy (750 kHz) was delivered between two adjacent poles of an electrode catheter. Single applications were performed at distinct sites in the left (n = 30) and right ventricles (n = 29) of 13 normal dogs. A multiple sequential technique, which enlarges the ablated endocardial surface, was applied in the left (n = 13) and right ventricles (n = 4) of seven normal dogs and six dogs with remote myocardial infarction. Single applications (199 +/- 200 joules) resulted in lesions with a volume of 0.12 +/- 0.06 cm3 (range 0.03 to 0.31 cm3) and an endocardial surface area of 0.29 +/- 0.15 cm2 (range 0.06 to 0.63 cm2). Changes at the catheter/tissue interface led to a rise in impedance, restricting further enlargement of the necrosis. Sequential delivery of radiofrequency energy between poles 1 and 2, 2 and 3, and 3 and 4 of a quadripolar electrode catheter repeated 9 to 11 times in slightly different positions allowed a cumulative energy of 6571 +/- 3857 joules to be applied to the endocardium, resulting in a lesion volume of 0.84 +/- 0.38 cm3, with an endocardial lesion surface area of 3.7 +/- 1.2 cm2 (range 2.9 to 5.1 cm2). Histologically, all radiofrequency lesions were restricted to the endocardium/subendocardium with a small border zone of injury. Aggressive stimulation techniques did not induce ventricular tachycardia in any of the dogs before and 19 +/- 11.4 days after multiple sequential ablations.

  19. Rational Design of Orthogonal Multipolar Interactions with Fluorine in Protein-Ligand Complexes.

    PubMed

    Pollock, Jonathan; Borkin, Dmitry; Lund, George; Purohit, Trupta; Dyguda-Kazimierowicz, Edyta; Grembecka, Jolanta; Cierpicki, Tomasz

    2015-09-24

    Multipolar interactions involving fluorine and the protein backbone have been frequently observed in protein-ligand complexes. Such fluorine-backbone interactions may substantially contribute to the high affinity of small molecule inhibitors. Here we found that introduction of trifluoromethyl groups into two different sites in the thienopyrimidine class of menin-MLL inhibitors considerably improved their inhibitory activity. In both cases, trifluoromethyl groups are engaged in short interactions with the backbone of menin. In order to understand the effect of fluorine, we synthesized a series of analogues by systematically changing the number of fluorine atoms, and we determined high-resolution crystal structures of the complexes with menin. We found that introduction of fluorine at favorable geometry for interactions with backbone carbonyls may improve the activity of menin-MLL inhibitors as much as 5- to 10-fold. In order to facilitate the design of multipolar fluorine-backbone interactions in protein-ligand complexes, we developed a computational algorithm named FMAP, which calculates fluorophilic sites in proximity to the protein backbone. We demonstrated that FMAP could be used to rationalize improvement in the activity of known protein inhibitors upon introduction of fluorine. Furthermore, FMAP may also represent a valuable tool for designing new fluorine substitutions and support ligand optimization in drug discovery projects. Analysis of the menin-MLL inhibitor complexes revealed that the backbone in secondary structures is particularly accessible to the interactions with fluorine. Considering that secondary structure elements are frequently exposed at protein interfaces, we postulate that multipolar fluorine-backbone interactions may represent a particularly attractive approach to improve inhibitors of protein-protein interactions.

  20. Post-Newtonian factorized multipolar waveforms for spinning, nonprecessing black-hole binaries

    SciTech Connect

    Pan, Yi; Buonanno, Alessandra; Racine, Etienne; Fujita, Ryuichi; Tagoshi, Hideyuki

    2011-03-15

    We generalize the factorized resummation of multipolar waveforms introduced by Damour, Iyer, and Nagar to spinning black holes. For a nonspinning test particle spiraling a Kerr black hole in the equatorial plane, we find that factorized multipolar amplitudes which replace the residual relativistic amplitude f{sub lm} with its lth root, {rho}{sub lm}=f{sub lm}{sup 1/l}, agree quite well with the numerical amplitudes up to the Kerr-spin value q{<=}0.95 for orbital velocities v{<=}0.4. The numerical amplitudes are computed solving the Teukolsky equation with a spectral code. The agreement for prograde orbits and large spin values of the Kerr black-hole can be further improved at high velocities by properly factoring out the lower-order post-Newtonian contributions in {rho}{sub lm}. The resummation procedure results in a better and systematic agreement between numerical and analytical amplitudes (and energy fluxes) than standard Taylor-expanded post-Newtonian approximants. This is particularly true for higher-order modes, such as (2,1), (3,3), (3,2), and (4,4), for which less spin post-Newtonian terms are known. We also extend the factorized resummation of multipolar amplitudes to generic mass-ratio, nonprecessing, spinning black holes. Lastly, in our study we employ new, recently computed, higher-order post-Newtonian terms in several subdominant modes and compute explicit expressions for the half and one-and-half post-Newtonian contributions to the odd-parity (current) and even-parity (odd) multipoles, respectively. Those results can be used to build more accurate templates for ground-based and space-based gravitational-wave detectors.

  1. Effective medium multipolar tensor analysis of second-harmonic generation from metal nanoparticles

    NASA Astrophysics Data System (ADS)

    Zdanowicz, Mariusz; Kujala, Sami; Husu, Hannu; Kauranen, Martti

    2011-02-01

    We present a detailed multipolar tensor analysis of second-harmonic (SH) generation from arrays of L-shaped gold nanoparticles. We define three effective nonlinear tensors, which include electric dipoles only (Aeee) and lowest-order magnetic (and quadrupole) effects at the fundamental (Aeem) and the SH (Amee) frequency. The components of the various tensors are distinguished through their different transformations as the experimental geometry is varied. The response is dominated by electric-dipole effects. However, the higher multipoles also play a significant role and are more important at the fundamental frequency than at the SH frequency. The results correlate well with the particles' plasmonic resonances and symmetry rules.

  2. Optical Photometry of BY Cam Modeled Using a Multipolar Magnetic Field Structure

    NASA Astrophysics Data System (ADS)

    Morales, John; Mason, P. A.; Zhilkin, A.; Bisikalo, D. V.; Robinson, E. L.

    2014-01-01

    We present new high-speed broad-band optical photometry of the asynchronous polar (magnetic cataclysmic variable) BY Cam. Observations were obtained at the 2.1-m Otto Struve Telescope of McDonald observatory with 3s integration times. In an attempt to understand the complex changes in accretion flow geometry, we performed full 3D MHD simulations assuming a variety of white dwarf magnetic field structures including both aligned and non-aligned dipole plus quadrupole field components. We compare model predictions with photometry and various phases of the beat cycle and find that synthetic light curves derived from a multipolar field structure are consistent with the optical photometry.

  3. MEG (Magnetoencephalography) multipolar modeling of distributed sources using RAP-MUSIC (Recursively Applied and Projected Multiple Signal Characterization)

    SciTech Connect

    Mosher, J. C.; Baillet, S.; Jerbi, K.; Leahy, R. M.

    2001-01-01

    We describe the use of truncated multipolar expansions for producing dynamic images of cortical neural activation from measurements of the magnetoencephalogram. We use a signal-subspace method to find the locations of a set of multipolar sources, each of which represents a region of activity in the cerebral cortex. Our method builds up an estimate of the sources in a recursive manner, i.e. we first search for point current dipoles, then magnetic dipoles, and finally first order multipoles. The dynamic behavior of these sources is then computed using a linear fit to the spatiotemporal data. The final step in the procedure is to map each of the multipolar sources into an equivalent distributed source on the cortical surface. The method is illustrated through an application to epileptic interictal MEG data.

  4. An axosomatic and axodendritic multipolar neuron in the lizard cerebral cortex.

    PubMed Central

    Bernabeu, A; Martinez-Guijarro, F J; de la Iglesia, J A; Lopez-Garcia, C

    1994-01-01

    The morphology and synaptic organisation of a type of multipolar neuron of the lizard cerebral cortex were studied by Golgi impregnation, intracellular injection of horseradish peroxidase, electron microscopy, and immunocytochemistry. It is a GABA-immunoreactive interneuron and most likely parvalbumin-immunoreactive. Its conspicuous axonal arbor is characterised by an initial segment arising from the soma or from a juxtasomatic dendritic segment. The initial axon segment ramifies and gives rise to thick myelinated segments that terminate in short unmyelinated branches studded with thick boutons 'en passant' that (1) make axosomatic synapses on bipyramidal neuronal somata and (2) synapse on initial apical dendritic segments of bipyramidal neurons forming climbing-like cartridges. The dendrites extend throughout the thickness of the cortex, receiving synaptic input from a variety of sources of which the most prominent is that of zinc-positive boutons coming from granule cells of the medial cortex. According to its synaptology, this interneuron may play a role in regulating the activity of bipyramidal neurons by both feed-forward and feed-back inhibition mechanisms. From a comparative standpoint, it may be related to the sparsely spiny or nonspiny multipolar neurons of the stratum oriens of the mammalian hippocampus. Images Fig. 1 Fig. 4 Fig. 6 Fig. 7 Fig. 8 PMID:7928645

  5. Effects of Multipolar Radiofrequency and Pulsed Electromagnetic Field Treatment for Face and Neck Rejuvenation

    PubMed Central

    de Oliveira, Thais Cristina Ferraz; Rocha, Sheyla de Fatima Soares; Ramos, Daniel Gontijo; Ramos, Camila Gontijo; Carvalho, Michelle Vanessa dos Anjos

    2017-01-01

    Skin aging is a gradual process that leads to wrinkle formation, laxity, and overall changes in skin appearance. In recent years, the demands to noninvasive treatments for facial rejuvenation increased, along with a variety of technologies and devices, such as radiofrequency. The present study aimed to evaluate the clinical effects of a multipolar radiofrequency and pulsed electromagnetic field treatment for face and neck rejuvenation. Eleven patients with mild to moderate grades of photoaging underwent eight radiofrequency and pulsed electromagnetic field treatment sessions, once a week. Clinical photographs were taken before and a week after the end of the treatment, and improvement of facial skin parameters was evaluated by two different investigators. Significant improvement in skin laxity was observed in all eleven patients (100%). Improvement in facial contour was noted in 73% and 100% of patients when analyzed by investigators A and B, respectively. The score for overall improvement in skin condition was 3 ± 0.78 for investigator A and 3.6 ± 0.67 for investigator B. All patients were satisfied with the procedure and noted significant improvement in the skin. The combined multipolar radiofrequency and pulsed electromagnetic field device is effective and safe for treatment of aged skin in Brazilian patients. PMID:28373880

  6. Properties of liquid water from a systematic refinement of a high-rank multipolar electrostatic potential.

    PubMed

    Shaik, Majeed S; Liem, Steven Y; Popelier, Paul L A

    2010-05-07

    We build on previous work [S. Y. Liem and P. L. A. Popelier, J. Chem. Theory Comput. 4, 353 (2008)], where for the first time, a high-rank multipolar electrostatic potential was used in molecular dynamics simulations of liquid water at a wide range of pressures and temperatures, and using a multipolar Ewald summation. Water is represented as a rigid body, with atomic multipole moments defined by quantum chemical topology partitioning its gas phase electron density. The effect of the level of theory on the local structure of liquid water is systematically addressed. Values for Lennard-Jones (LJ) parameters are optimized, for both oxygen and hydrogen atoms, against bulk properties. The best LJ parameters were then used in a set of simulations at 30 different temperatures (1 atm) and another set at 11 different pressures (at 298 K). Inclusion of the hydrogen LJ parameters significantly increases the self-diffusion coefficient. The behavior of bulk properties was studied and the local water structure analyzed by both radial and spatial distribution functions. Comparisons with familiar point-charge potentials, such as TIP3P, TIP4P, TIP5P, and simple point charge, show the benefits of multipole moments.

  7. Output of acoustical sources. [effects of structural elements and background flow on immobile multipolar point radiation

    NASA Technical Reports Server (NTRS)

    Levine, H.

    1980-01-01

    Acoustic radiation from a source, here viewed as an immobile point singularity with periodic strength and a given multipolar nature, is affected by the presence of nearly structural elements (e.g., rigid or impedance surfaces) as well as that of a background flow in the medium. An alternative to the conventional manner of calculating the net source output by integrating the energy flux over a distant control surface is described; this involves a direct evaluation of the secondary wavefunction at the position of the primary source and obviates the need for a (prospectively difficult) flux integration. Various full and half-planar surface configurations with an adjacent source are analyzed in detail, and the explicit results obtained, in particular, for the power factor of a dipole brings out a substantial rise in its output as the source nears the sharp edge of a half-plane.

  8. Multifrequency, Multipolarization External Calibration of the SIR-C/X-SAR Radars

    NASA Technical Reports Server (NTRS)

    Freeman, Anthony; Sarabandi, K.

    1996-01-01

    Progress and the future plans for the following objectives are discussed: (1) Assess the accuracy at which the SIR-C/X-SAR standard data products can be calibrated through the use of ground calibrators to estimate the end-to-end system polarization calibration constants (or distortion parameters) and incorporate the constants into the data processing; (2) Study the cross-calibration between three multipolarization systems: SIR-C, the National Aeronautics and Space Administration/Jet Propulsion Laboratory (NASA/JPL) DC-8 SAR, and the University of Michigan ground-based polarimetric scatterometer; (3) Evaluate the calibration "stability" of SIR-C/X-SAR (measured by variations in the calibration constants) over the range swath width and over a specified distance in azimuth. Variations over a 12-hour period (between ascending and descending passes) will also be studied; and (4) Develop a cost-effective calibration plan including development of inexpensive polarimetric active calibrators.

  9. Estimation of Soil Moisture with L-band Multi-polarization Radar

    NASA Technical Reports Server (NTRS)

    Shi, J.; Chen, K. S.; Kim, Chung-Li Y.; Van Zyl, J. J.; Njoku, E.; Sun, G.; O'Neill, P.; Jackson, T.; Entekhabi, D.

    2004-01-01

    Through analyses of the model simulated data-base, we developed a technique to estimate surface soil moisture under HYDROS radar sensor (L-band multi-polarizations and 40deg incidence) configuration. This technique includes two steps. First, it decomposes the total backscattering signals into two components - the surface scattering components (the bare surface backscattering signals attenuated by the overlaying vegetation layer) and the sum of the direct volume scattering components and surface-volume interaction components at different polarizations. From the model simulated data-base, our decomposition technique works quit well in estimation of the surface scattering components with RMSEs of 0.12,0.25, and 0.55 dB for VV, HH, and VH polarizations, respectively. Then, we use the decomposed surface backscattering signals to estimate the soil moisture and the combined surface roughness and vegetation attenuation correction factors with all three polarizations.

  10. Phonon Dynamics and Multipolar Isomorphic Transition in β-Pyrochlore KOs2O6

    NASA Astrophysics Data System (ADS)

    Hattori, Kazumasa

    2011-02-01

    We investigate with a microscopic model anharmonic K-cation oscillation observed by neutron experiments in β-pyrochlore superconductor KOs2O6, which also shows a mysterious first-order structural transition at Tp = 7.5 K. We have identified a set of microscopic model parameters that successfully reproduce the observed tem perature dependence and the superconducting transition temperature. Considering changes in the parameters at Tp, we can explain puzzling experimental results about electron--phonon coupling and neutron data. Our analysis demonstrates that the first-order transition is multipolar transition driven by the octupolar component of K-cation oscillations. The octupole moment does not change the symmetry and is characteristic to noncentrosymmetric K-cation potential.

  11. An improved experimental databank of transferable multipolar atom models--ELMAM2. Construction details and applications.

    PubMed

    Domagała, Sławomir; Fournier, Bertrand; Liebschner, Dorothee; Guillot, Benoît; Jelsch, Christian

    2012-05-01

    ELMAM2 is a generalized and improved library of experimentally derived multipolar atom types. The previously published ELMAM database is restricted mostly to protein atoms. The current database is extended to common functional groups encountered in organic molecules and is based on optimized local axes systems taking into account the local pseudosymmetry of the molecular fragment. In this approach, the symmetry-restricted multipoles have zero populations, while others take generally significant values. The various applications of the database are described. The deformation electron densities, electrostatic potentials and interaction energies calculated for several tripeptides and aromatic molecules are calculated using ELMAM2 electron-density parameters and compared with the former ELMAM database and density functional theory calculations.

  12. FMRP regulates multipolar to bipolar transition affecting neuronal migration and cortical circuitry.

    PubMed

    La Fata, Giorgio; Gärtner, Annette; Domínguez-Iturza, Nuria; Dresselaers, Tom; Dawitz, Julia; Poorthuis, Rogier B; Averna, Michele; Himmelreich, Uwe; Meredith, Rhiannon M; Achsel, Tilmann; Dotti, Carlos G; Bagni, Claudia

    2014-12-01

    Deficiencies in fragile X mental retardation protein (FMRP) are the most common cause of inherited intellectual disability, fragile X syndrome (FXS), with symptoms manifesting during infancy and early childhood. Using a mouse model for FXS, we found that Fmrp regulates the positioning of neurons in the cortical plate during embryonic development, affecting their multipolar-to-bipolar transition (MBT). We identified N-cadherin, which is crucial for MBT, as an Fmrp-regulated target in embryonic brain. Furthermore, spontaneous network activity and high-resolution brain imaging revealed defects in the establishment of neuronal networks at very early developmental stages, further confirmed by an unbalanced excitatory and inhibitory network. Finally, reintroduction of Fmrp or N-cadherin in the embryo normalized early postnatal neuron activity. Our findings highlight the critical role of Fmrp in the developing cerebral cortex and might explain some of the clinical features observed in patients with FXS, such as alterations in synaptic communication and neuronal network connectivity.

  13. Nesting-driven multipolar order in CeB6 from photoemission tomography

    PubMed Central

    Koitzsch, A.; Heming, N.; Knupfer, M.; Büchner, B.; Portnichenko, P. Y.; Dukhnenko, A. V; Shitsevalova, N. Y.; Filipov, V. B.; Lev, L. L.; Strocov, V. N.; Ollivier, J.; Inosov, D. S.

    2016-01-01

    Some heavy fermion materials show so-called hidden-order phases which are invisible to many characterization techniques and whose microscopic origin remained controversial for decades. Among such hidden-order compounds, CeB6 is of model character due to its simple electronic configuration and crystal structure. Apart from more conventional antiferromagnetism, it shows an elusive phase at low temperatures, which is commonly associated with multipolar order. Here we show that this phase roots in a Fermi surface instability. This conclusion is based on a full 3D tomographic sampling of the electronic structure by angle-resolved photoemission and comparison with inelastic neutron scattering data. The hidden order is mediated by itinerant electrons. Our measurements will serve as a paradigm for the investigation of hidden-order phases in f-electron systems, but also generally for situations where the itinerant electrons drive orbital or spin order. PMID:26976632

  14. The multiple functions of T stellate/multipolar/chopper cells in the ventral cochlear nucleus.

    PubMed

    Oertel, Donata; Wright, Samantha; Cao, Xiao-Jie; Ferragamo, Michael; Bal, Ramazan

    2011-06-01

    Acoustic information is brought to the brain by auditory nerve fibers, all of which terminate in the cochlear nuclei, and is passed up the auditory pathway through the principal cells of the cochlear nuclei. A population of neurons variously known as T stellate, type I multipolar, planar multipolar, or chopper cells forms one of the major ascending auditory pathways through the brainstem. T Stellate cells are sharply tuned; as a population they encode the spectrum of sounds. In these neurons, phasic excitation from the auditory nerve is made more tonic by feedforward excitation, coactivation of inhibitory with excitatory inputs, relatively large excitatory currents through NMDA receptors, and relatively little synaptic depression. The mechanisms that make firing tonic also obscure the fine structure of sounds that is represented in the excitatory inputs from the auditory nerve and account for the characteristic chopping response patterns with which T stellate cells respond to tones. In contrast with other principal cells of the ventral cochlear nucleus (VCN), T stellate cells lack a low-voltage-activated potassium conductance and are therefore sensitive to small, steady, neuromodulating currents. The presence of cholinergic, serotonergic and noradrenergic receptors allows the excitability of these cells to be modulated by medial olivocochlear efferent neurons and by neuronal circuits associated with arousal. T Stellate cells deliver acoustic information to the ipsilateral dorsal cochlear nucleus (DCN), ventral nucleus of the trapezoid body (VNTB), periolivary regions around the lateral superior olivary nucleus (LSO), and to the contralateral ventral lemniscal nuclei (VNLL) and inferior colliculus (IC). It is likely that T stellate cells participate in feedback loops through both medial and lateral olivocochlear efferent neurons and they may be a source of ipsilateral excitation of the LSO.

  15. Ultrastructure and immunocytochemical characteristics of cells in the octopus cell area of the rat cochlear nucleus: comparison with multipolar cells.

    PubMed

    Alibardi, Lorenzo

    2003-01-01

    Cells in the octopus cell area of the rat ventral cochlear nucleus have been connected to the monaural interpretation of spectral patterns of sound such as those derived from speech. This is possible by their fast onset of firing after each octopus cell and its dendrites have been contacted by many auditory fibres carrying different frequencies. The cytological characteristics that make these large cells able to perform such a function have been studied with ultrastructural immunocytochemistry for glycine, GABA and glutamate, and compared to that of other multipolar neurons of other regions of the ventral cochlear nucleus. Cells in the octopus cell area have an ultrastructure similar to large-giant D-multipolar neurons present in other areas of the cochlear nucleus, from which they differ by the presence of a larger excitatory axo-somatic synaptic input and larger mitochondria. Octopus cells are glycine and GABA negative, and glutamate positive with different degree. Large octopus cells receive more axo-somatic boutons than smaller octopus cells. Fusiform octopus cells are found sparsely within the intermediate acoustic striae. These cells are large to giant excitatory neurons (23-35 microm) with 62-85% of their irregular perimeter covered with large axo-somatic synaptic boutons. Most boutons contain round vesicles and are glycine and GABA negative but glutamate positive. The latter excitatory boutons represent about 70% of the input to octopus cells. Glycine positive boutons with flat and pleomorphic vesicles account for 9-10% of the input while GABA-ergic boutons with pleomorphic vesicles represent about 20% of the synaptic input. Other few, multipolar cells within the rat octopus cell area are surrounded by more inhibitory than excitatory terminals which contain flat and pleomorphic vesicles, a feature distinctive from that of true octopus cells. The latter resemble multipolar cells seen outside the octopus cell area that project to the contralateral inferior

  16. Reelin, Rap1 and N-cadherin orient the migration of multipolar neurons in the developing neocortex.

    PubMed

    Jossin, Yves; Cooper, Jonathan A

    2011-06-01

    Projection neurons migrate from the ventricular zone to the neocortical plate during the development of the mouse brain. Their overall movement is radial, but they become multipolar and move nonradially in the intermediate zone. Here we show that Reelin, the Rap1 GTPase and N-cadherin (NCad) are important for multipolar neurons to polarize their migration toward the cortical plate. Inhibition and rescue experiments indicated that Reelin regulates migration through Rap1 and Akt, and that the Rap1-regulated GTPases RalA, RalB, Rac1 and Cdc42 are also involved. We found that Rap1 regulated the plasma membrane localization of NCad and NCad rescued radial polarization when Rap1 was inhibited. However, inhibition of Rap1 or NCad had little effect on glia-dependent locomotion. We propose a multistep mechanism in which Reelin activates Rap1, Rap1 upregulates NCad, and NCad is needed to orient cell migration.

  17. ADAM17 is critical for multipolar exit and radial migration of neuronal intermediate progenitor cells in mice cerebral cortex.

    PubMed

    Li, Qingyu; Zhang, Zhengyu; Li, Zengmin; Zhou, Mei; Liu, Bin; Pan, Le; Ma, Zhixing; Zheng, Yufang

    2013-01-01

    The radial migration of neuronal progenitor cells is critical for the development of cerebral cortex layers. They go through a critical step transforming from multipolar to bipolar before outward migration. A Disintegrin and Metalloprotease 17 (ADAM17) is a transmembrane protease which can process many substrates involved in cell-cell interaction, including Notch, ligands of EGFR, and some cell adhesion molecules. In this study, we used in utero electroporation to knock down or overexpress ADAM17 at embryonic day 14.5 (E14.5) in neuronal progenitor cells to examine the role of ADAM17 in cortical embryonic neurogenesis. Our results showed that the radial migration of ADAM17-knocked down cells were normal till E16.5 and reached the intermediate zone (IZ). Then most transfected cells stopped migration and stayed at the IZ to inner cortical plate (CP) layer at E18.5, and there was higher percentage of multipolar cells at IZ layer in the ADAM17-knocked down group compared to the cells in control group. Marker staining revealed that those ADAM17-knocked down cells differentiated normally from neural stem cells (NSCs) to neuronal intermediate progenitor cells (nIPCs) but did not differentiate into mature neurons. The migration and multipolar exit defects caused by ADAM17 knockdown could be partially rescued by over-expressing an shRNA resistant ADAM17, while overexpressing ADAM17 alone did not affect the radial migration. Taken together, our results showed for the first time that, ADAM17 is critical in regulating the multipolar-stage exit and radial migration of the nIPCs during telencephalon cortex development in mice.

  18. Huntingtin-Mediated Multipolar-Bipolar Transition of Newborn Cortical Neurons Is Critical for Their Postnatal Neuronal Morphology.

    PubMed

    Barnat, Monia; Le Friec, Julien; Benstaali, Caroline; Humbert, Sandrine

    2017-01-04

    In the developing cortex, projection neurons undergo multipolar-bipolar transition, radial-directed migration, and maturation. The contribution of these developmental steps to the structure of the adult cortex is not completely understood. Here, we report that huntingtin (HTT), the protein mutated in Huntington's disease, is enriched in polarizing projection neurons. The depletion of HTT in postmitotic projection neurons leads to the mislocalization of layer-specific neuronal populations in the mouse neocortex. HTT is required for the multipolar-bipolar transition of projection neurons and for the maintenance of their bipolar shape during their radial migration. HTT mediates these effects in vivo through the regulation of RAB11-dependent N-Cadherin trafficking. Importantly, HD pathological HTT alters RAB11-dependent neuronal migration. Finally, we show that the cortical defects resulting from the postmitotic loss of HTT specifically during embryonic development affect neuronal morphology at adulthood. Our data reveal a new HTT-RAB11-N-Cadherin pathway regulating multipolar-bipolar transition with direct implications for mature brain. VIDEO ABSTRACT.

  19. Multipolarity of the 2-→1- , ground-state transition in 210Bi via multivariable angular correlation analysis

    NASA Astrophysics Data System (ADS)

    Cieplicka-Oryńczak, N.; Szpak, B.; Leoni, S.; Fornal, B.; Bazzacco, D.; Blanc, A.; Bocchi, G.; Bottoni, S.; de France, G.; Jentschel, M.; Köster, U.; Mutti, P.; Simpson, G.; Soldner, T.; Ur, C.; Urban, W.

    2016-07-01

    The multipolarity of the main transition leading to the ground state in 210Bi was investigated using the angular correlations of γ rays. The analyzed γ -coincidence data were obtained from the 209Bi(n ,γ )210Bi experiment performed at Institut Laue-Langevin Grenoble at the PF1B cold-neutron facility. The EXILL (EXOGAM at the ILL) multidetector array, consisting of 16 high-purity germanium detectors, was used to detect γ transitions. The mixing ratio of the 320-keV γ ray was defined by minimizing a multivariable χΣ2 function constructed from the coefficients of angular correlation functions for seven pairs of strong transitions in 210Bi. As a result, the almost pure M 1 multipolarity of the 320-keV γ ray was obtained, with an E 2 admixture of less than 0.6% only (95% confidence limit). Based on this multipolarity the neutron-capture cross section leading to the ground state in 210Bi, that decays in turn to radiotoxic 210Po, was determined to be within the limits 21.3(9) and 21.5(9) mb. This result is important for nuclear reactor applications.

  20. The Slope Imaging Multi-Polarization Photon-Counting Lidar: Development and Performance Results

    NASA Technical Reports Server (NTRS)

    Dabney, Phillip

    2010-01-01

    The Slope Imaging Multi-polarization Photon-counting Lidar is an airborne instrument developed to demonstrate laser altimetry measurement methods that will enable more efficient observations of topography and surface properties from space. The instrument was developed through the NASA Earth Science Technology Office Instrument Incubator Program with a focus on cryosphere remote sensing. The SIMPL transmitter is an 11 KHz, 1064 nm, plane-polarized micropulse laser transmitter that is frequency doubled to 532 nm and split into four push-broom beams. The receiver employs single-photon, polarimetric ranging at 532 and 1064 nm using Single Photon Counting Modules in order to achieve simultaneous sampling of surface elevation, slope, roughness and depolarizing scattering properties, the latter used to differentiate surface types. Data acquired over ice-covered Lake Erie in February, 2009 are documenting SIMPL s measurement performance and capabilities, demonstrating differentiation of open water and several ice cover types. ICESat-2 will employ several of the technologies advanced by SIMPL, including micropulse, single photon ranging in a multi-beam, push-broom configuration operating at 532 nm.

  1. THE SHAPING OF THE MULTIPOLAR PRE-PLANETARY NEBULA CRL 618 BY MULTIDIRECTIONAL BULLETS

    SciTech Connect

    Huang, Po-Sheng; Lee, Chin-Fei; Moraghan, Anthony; Smith, Michael

    2016-04-01

    In order to understand the formation of the multipolar structures of the pre-planetary nebula CRL 618, we perform 3D simulations using a multidirectional bullet model. The optical lobes of CRL 618 and fast molecular outflows at the tips of the lobes have been found to have similar expansion ages of ∼100 yr. Additional fast molecular outflows were found near the source along the outflow axes with ages of ∼45 yr, suggesting a second episode of bullet ejections. Thus, in our simulations, two episodes of bullet ejections are assumed. The shaping process is simulated using the ZEUS-3D hydrodynamics code that includes molecular and atomic cooling. In addition, molecular chemistry is also included to calculate the CO intensity maps. Our results show the following: (1) Multiepoch bullets interacting with the toroidal dense core can produce the collimated multiple lobes as seen in CRL 618. The total mass of the bullets is ∼0.034 M{sub ⊙}, consistent with the observed high-velocity (HV) CO emission in fast molecular outflows. (2) The simulated CO J = 3–2 intensity maps show that the low-velocity cavity wall and the HV outflows along the lobes are reasonably consistent with the observations. The position–velocity diagram of the outflows along the outflow axes shows a linear increase of velocity with distance, similar to the observations. The ejections of these bullets could be due to magnetorotational explosions or nova-like explosions around a binary companion.

  2. The Shaping of the Multipolar Pre-planetary Nebula CRL 618 by Multidirectional Bullets

    NASA Astrophysics Data System (ADS)

    Huang, Po-Sheng; Lee, Chin-Fei; Moraghan, Anthony; Smith, Michael

    2016-04-01

    In order to understand the formation of the multipolar structures of the pre-planetary nebula CRL 618, we perform 3D simulations using a multidirectional bullet model. The optical lobes of CRL 618 and fast molecular outflows at the tips of the lobes have been found to have similar expansion ages of ˜100 yr. Additional fast molecular outflows were found near the source along the outflow axes with ages of ˜45 yr, suggesting a second episode of bullet ejections. Thus, in our simulations, two episodes of bullet ejections are assumed. The shaping process is simulated using the ZEUS-3D hydrodynamics code that includes molecular and atomic cooling. In addition, molecular chemistry is also included to calculate the CO intensity maps. Our results show the following: (1) Multiepoch bullets interacting with the toroidal dense core can produce the collimated multiple lobes as seen in CRL 618. The total mass of the bullets is ˜0.034 M⊙, consistent with the observed high-velocity (HV) CO emission in fast molecular outflows. (2) The simulated CO J = 3-2 intensity maps show that the low-velocity cavity wall and the HV outflows along the lobes are reasonably consistent with the observations. The position-velocity diagram of the outflows along the outflow axes shows a linear increase of velocity with distance, similar to the observations. The ejections of these bullets could be due to magnetorotational explosions or nova-like explosions around a binary companion.

  3. Role of the multipolar electrostatic interaction energy components in strong and weak cation-π interactions.

    PubMed

    Kadlubanski, Pawel; Calderón-Mojica, Katherine; Rodriguez, Weyshla A; Majumdar, D; Roszak, Szczepan; Leszczynski, Jerzy

    2013-08-22

    Density functional and Møller-Plesset second-order perturbation (MP2) calculations have been carried out on various model cation-π complexes formed through the interactions of Mg(2+), Ca(2+), and NH4(+) cations with benzene, p-methylphenol, and 3-methylindole. Partial hydration of the metal cations was also considered in these model studies to monitor the effect of hydration of cations in cation-π interactions. The binding energies of these complexes were computed from the fully optimized structures using coupled cluster calculations including triple excitations (CCSD(T)) and Gaussian-G4-MP2 (G4MP2) techniques. An analysis of the charge sharing between the donor (the π-systems) and the acceptors (the cations) together with the partitioning of total interaction energies revealed that the strong and weak cation-π interactions have similar electrostatic interaction properties. Further decomposition of such electrostatic terms into their multipolar components showed the importance of the charge-dipole, charge-quadrupole, and charge-octopole terms in shaping the electrostatic forces in such interactions. The computed vibrational spectra of the complexes were analyzed for the specific cation-π interaction modes and have been shown to contain the signature of higher order electrostatic interaction energy components (quadrupole and octopole) in such interactions.

  4. Multipolar Electrostatic Energy Prediction for all 20 Natural Amino Acids Using Kriging Machine Learning.

    PubMed

    Fletcher, Timothy L; Popelier, Paul L A

    2016-06-14

    A machine learning method called kriging is applied to the set of all 20 naturally occurring amino acids. Kriging models are built that predict electrostatic multipole moments for all topological atoms in any amino acid based on molecular geometry only. These models then predict molecular electrostatic interaction energies. On the basis of 200 unseen test geometries for each amino acid, no amino acid shows a mean prediction error above 5.3 kJ mol(-1), while the lowest error observed is 2.8 kJ mol(-1). The mean error across the entire set is only 4.2 kJ mol(-1) (or 1 kcal mol(-1)). Charged systems are created by protonating or deprotonating selected amino acids, and these show no significant deviation in prediction error over their neutral counterparts. Similarly, the proposed methodology can also handle amino acids with aromatic side chains, without the need for modification. Thus, we present a generic method capable of accurately capturing multipolar polarizable electrostatics in amino acids.

  5. Cholesterol oxidase: ultrahigh-resolution crystal structure and multipolar atom model-based analysis.

    PubMed

    Zarychta, Bartosz; Lyubimov, Artem; Ahmed, Maqsood; Munshi, Parthapratim; Guillot, Benoît; Vrielink, Alice; Jelsch, Christian

    2015-04-01

    Examination of protein structure at the subatomic level is required to improve the understanding of enzymatic function. For this purpose, X-ray diffraction data have been collected at 100 K from cholesterol oxidase crystals using synchrotron radiation to an optical resolution of 0.94 Å. After refinement using the spherical atom model, nonmodelled bonding peaks were detected in the Fourier residual electron density on some of the individual bonds. Well defined bond density was observed in the peptide plane after averaging maps on the residues with the lowest thermal motion. The multipolar electron density of the protein-cofactor complex was modelled by transfer of the ELMAM2 charge-density database, and the topology of the intermolecular interactions between the protein and the flavin adenine dinucleotide (FAD) cofactor was subsequently investigated. Taking advantage of the high resolution of the structure, the stereochemistry of main-chain bond lengths and of C=O···H-N hydrogen bonds was analyzed with respect to the different secondary-structure elements.

  6. CT-guided Bipolar and Multipolar Radiofrequency Ablation (RF Ablation) of Renal Cell Carcinoma: Specific Technical Aspects and Clinical Results

    SciTech Connect

    Sommer, C. M.; Lemm, G.; Hohenstein, E.; Bellemann, N.; Stampfl, U.; Goezen, A. S.; Rassweiler, J.; Kauczor, H. U.; Radeleff, B. A.; Pereira, P. L.

    2013-06-15

    Purpose. This study was designed to evaluate the clinical efficacy of CT-guided bipolar and multipolar radiofrequency ablation (RF ablation) of renal cell carcinoma (RCC) and to analyze specific technical aspects between both technologies. Methods. We included 22 consecutive patients (3 women; age 74.2 {+-} 8.6 years) after 28 CT-guided bipolar or multipolar RF ablations of 28 RCCs (diameter 2.5 {+-} 0.8 cm). Procedures were performed with a commercially available RF system (Celon AG Olympus, Berlin, Germany). Technical aspects of RF ablation procedures (ablation mode [bipolar or multipolar], number of applicators and ablation cycles, overall ablation time and deployed energy, and technical success rate) were analyzed. Clinical results (local recurrence-free survival and local tumor control rate, renal function [glomerular filtration rate (GFR)]) and complication rates were evaluated. Results. Bipolar RF ablation was performed in 12 procedures and multipolar RF ablation in 16 procedures (2 applicators in 14 procedures and 3 applicators in 2 procedures). One ablation cycle was performed in 15 procedures and two ablation cycles in 13 procedures. Overall ablation time and deployed energy were 35.0 {+-} 13.6 min and 43.7 {+-} 17.9 kJ. Technical success rate was 100 %. Major and minor complication rates were 4 and 14 %. At an imaging follow-up of 15.2 {+-} 8.8 months, local recurrence-free survival was 14.4 {+-} 8.8 months and local tumor control rate was 93 %. GFR did not deteriorate after RF ablation (50.8 {+-} 16.6 ml/min/1.73 m{sup 2} before RF ablation vs. 47.2 {+-} 11.9 ml/min/1.73 m{sup 2} after RF ablation; not significant). Conclusions. CT-guided bipolar and multipolar RF ablation of RCC has a high rate of clinical success and low complication rates. At short-term follow-up, clinical efficacy is high without deterioration of the renal function.

  7. Magnetar giant flares in multipolar magnetic fields. II. Flux rope eruptions with current sheets

    SciTech Connect

    Huang, Lei; Yu, Cong E-mail: cyu@ynao.ac.cn

    2014-11-20

    We propose a physical mechanism to explain giant flares and radio afterglows in terms of a magnetospheric model containing both a helically twisted flux rope and a current sheet (CS). With the appearance of a CS, we solve a mixed boundary value problem to get the magnetospheric field based on a domain decomposition method. We investigate properties of the equilibrium curve of the flux rope when the CS is present in background multipolar fields. In response to the variations at the magnetar surface, it quasi-statically evolves in stable equilibrium states. The loss of equilibrium occurs at a critical point and, beyond that point, it erupts catastrophically. New features show up when the CS is considered. In particular, we find two kinds of physical behaviors, i.e., catastrophic state transition and catastrophic escape. Magnetic energy would be released during state transitions. This released magnetic energy is sufficient to drive giant flares, and the flux rope would, therefore, go away from the magnetar quasi-statically, which is inconsistent with the radio afterglow. Fortunately, in the latter case, i.e., the catastrophic escape, the flux rope could escape the magnetar and go to infinity in a dynamical way. This is more consistent with radio afterglow observations of giant flares. We find that the minor radius of the flux rope has important implications for its eruption. Flux ropes with larger minor radii are more prone to erupt. We stress that the CS provides an ideal place for magnetic reconnection, which would further enhance the energy release during eruptions.

  8. Evaluation of focused multipolar stimulation for cochlear implants in long-term deafened cats

    NASA Astrophysics Data System (ADS)

    George, Shefin S.; Wise, Andrew K.; Fallon, James B.; Shepherd, Robert K.

    2015-06-01

    Objective. Focused multipolar (FMP) stimulation has been shown to produce restricted neural activation using intracochlear stimulation in animals with a normal population of spiral ganglion neurons (SGNs). However, in a clinical setting, the widespread loss of SGNs and peripheral fibres following deafness is expected to influence the effectiveness of FMP. Approach. We compared the efficacy of FMP stimulation to both monopolar (MP) and tripolar (TP) stimulation in long-term deafened cat cochleae (n = 8). Unlike our previous study, these cochleae contained <10% of the normal SGN population adjacent to the electrode array. We also evaluated the effect of electrode position on stimulation modes by using either modiolar facing or lateral wall facing half-band electrodes. The spread of neural activity across the inferior colliculus, a major nucleus within the central auditory pathway, was used as a measure of spatial selectivity. Main results. In cochleae with significant SGN degeneration, we observed that FMP and TP stimulation resulted in greater spatial selectivity than MP stimulation (p < 0.001). However, thresholds were significantly higher for FMP and TP stimulation compared to MP stimulation (p < 0.001). No difference between FMP and TP stimulation was found in any measures. The high threshold levels for FMP stimulation was significantly reduced without compromising spatial selectivity by varying the degree of current focusing (referred as ‘partial-FMP’ stimulation). Spatial selectivity of all stimulation modes was unaffected by the electrode position. Finally, spatial selectivity in long-term deafened cochleae was significantly less than that of cochleae with normal SGN population (George S S et al 2014 J. Neural Eng. 11 065003). Significance. The present results indicate that the greater spatial selectivity of FMP and TP stimulation over MP stimulation is maintained in cochleae with significant neural degeneration and is not adversely affected by electrode

  9. Multipolar Ewald Methods, 2: Applications Using a Quantum Mechanical Force Field

    PubMed Central

    2015-01-01

    A fully quantum mechanical force field (QMFF) based on a modified “divide-and-conquer” (mDC) framework is applied to a series of molecular simulation applications, using a generalized Particle Mesh Ewald method extended to multipolar charge densities. Simulation results are presented for three example applications: liquid water, p-nitrophenylphosphate reactivity in solution, and crystalline N,N-dimethylglycine. Simulations of liquid water using a parametrized mDC model are compared to TIP3P and TIP4P/Ew water models and experiment. The mDC model is shown to be superior for cluster binding energies and generally comparable for bulk properties. Examination of the dissociative pathway for dephosphorylation of p-nitrophenylphosphate shows that the mDC method evaluated with the DFTB3/3OB and DFTB3/OPhyd semiempirical models bracket the experimental barrier, whereas DFTB2 and AM1/d-PhoT QM/MM simulations exhibit deficiencies in the barriers, the latter for which is related, in part, to the anomalous underestimation of the p-nitrophenylate leaving group pKa. Simulations of crystalline N,N-dimethylglycine are performed and the overall structure and atomic fluctuations are compared with the experiment and the general AMBER force field (GAFF). The QMFF, which was not parametrized for this application, was shown to be in better agreement with crystallographic data than GAFF. Our simulations highlight some of the application areas that may benefit from using new QMFFs, and they demonstrate progress toward the development of accurate QMFFs using the recently developed mDC framework. PMID:25691830

  10. Multipolar Ewald methods, 2: applications using a quantum mechanical force field.

    PubMed

    Giese, Timothy J; Panteva, Maria T; Chen, Haoyuan; York, Darrin M

    2015-02-10

    A fully quantum mechanical force field (QMFF) based on a modified “divide-and-conquer” (mDC) framework is applied to a series of molecular simulation applications, using a generalized Particle Mesh Ewald method extended to multipolar charge densities. Simulation results are presented for three example applications: liquid water, p-nitrophenylphosphate reactivity in solution, and crystalline N,N-dimethylglycine. Simulations of liquid water using a parametrized mDC model are compared to TIP3P and TIP4P/Ew water models and experiment. The mDC model is shown to be superior for cluster binding energies and generally comparable for bulk properties. Examination of the dissociative pathway for dephosphorylation of p-nitrophenylphosphate shows that the mDC method evaluated with the DFTB3/3OB and DFTB3/OPhyd semiempirical models bracket the experimental barrier, whereas DFTB2 and AM1/d-PhoT QM/MM simulations exhibit deficiencies in the barriers, the latter for which is related, in part, to the anomalous underestimation of the p-nitrophenylate leaving group pKa. Simulations of crystalline N,N-dimethylglycine are performed and the overall structure and atomic fluctuations are compared with the experiment and the general AMBER force field (GAFF). The QMFF, which was not parametrized for this application, was shown to be in better agreement with crystallographic data than GAFF. Our simulations highlight some of the application areas that may benefit from using new QMFFs, and they demonstrate progress toward the development of accurate QMFFs using the recently developed mDC framework.

  11. Evaluation of focused multipolar stimulation for cochlear implants in acutely deafened cats

    NASA Astrophysics Data System (ADS)

    George, Shefin S.; Wise, Andrew K.; Shivdasani, Mohit N.; Shepherd, Robert K.; Fallon, James B.

    2014-12-01

    Objective. The conductive nature of the fluids and tissues of the cochlea can lead to broad activation of spiral ganglion neurons using contemporary cochlear implant stimulation configurations such as monopolar (MP) stimulation. The relatively poor spatial selectivity is thought to limit implant performance, particularly in noisy environments. Several current focusing techniques have been proposed to reduce the spread of activation with the aim towards achieving improved clinical performance. Approach. The present research evaluated the efficacy of focused multipolar (FMP) stimulation, a relatively new focusing technique in the cochlea, and compared its efficacy to both MP stimulation and tripolar (TP) stimulation. The spread of neural activity across the inferior colliculus (IC), measured by recording the spatial tuning curve, was used as a measure of spatial selectivity. Adult cats (n = 6) were acutely deafened and implanted with an intracochlear electrode array before multi-unit responses were recorded across the cochleotopic gradient of the contralateral IC. Recordings were made in response to acoustic and electrical stimulation using the MP, TP and FMP configurations. Main results. FMP and TP stimulation resulted in greater spatial selectivity than MP stimulation. However, thresholds were significantly higher (p < 0.001) for FMP and TP stimulation compared to MP stimulation. There were no differences found in spatial selectivity and threshold between FMP and TP stimulation. Significance. The greater spatial selectivity of FMP and TP stimulation would be expected to result in improved clinical performance. However, further research will be required to demonstrate the efficacy of these modes of stimulation after longer durations of deafness.

  12. Analysis of Multi-Polarization Switching in Vertical-Cavity Surface-Emitting Lasers Using Multi-peak gain model

    NASA Astrophysics Data System (ADS)

    Hsu, Chuan; Chen, Yu-Fong; Chin, Pei-Hou; Quadir, Shaham; Li, Yueh-Chen; Wu, Yu-Heng; Yen, Tsu-Chiang

    2013-03-01

    This research investigated the mulit-polarization switching (MPS) in vertical-cavity surface-emitting lasers (VCSELs) at constant temperature by simple multi-peak gain model.In experimental results, the phenomenon of the polarization switching (PS) in the VCSEL were arduous to definite quantitative analysis. A simple multi-peak gain model which included the temperature effect and current effect was established to match the MPS in the VCSEL. Simulation results match the experimental results well and shoe that the variation of temperature is a affecting factor of MPS. Therefore, the simple multi-peak gain model contributed a good understanding of multi-polarization switching in VCSELs.

  13. [Morphometry of giant multipolar neurons of the brain stem reticular formation in rats on board the Kosmos-1667 biosatellite].

    PubMed

    Belichenko, P V; Leontovich, T A

    1989-05-01

    Giant multipolar neurons of nucleus reticularis gigantocellularis of rats which had been kept on board the biosatellite "Kosmos-1667" were morphometrically studied. There was a trend towards the increase in the cellular surface, the maximum diameter of dendritic field, the volume of the whole dendritic territory in the test group ad in the control experimental group kept on the earth. A reliable decrease in dendritic mass oriented to nucleus vestibularis and an increase in dendritic mass oriented to the midline were also found in test group, as compared to 3 control groups. Our data were discussed in the light of nervous tissue plasticity in adult mammals.

  14. 4-Benzoyl-3,4-dihydro-2H-1,4-benzoxazine-2-carbonitrile: refinement using a multipolar atom model.

    PubMed

    Ejsmont, Krzysztof; Joly, Jean Pierre; Wenger, Emmanuel; Guillot, Benoit; Jelsch, Christian

    2009-07-01

    The structural model for the title compound, C(16)H(12)N(2)O(2), was refined using a multipolar atom model transferred from an experimental electron-density database. The refinement showed some improvements of crystallographic statistical indices when compared with a conventional spherical neutral-atom refinement. The title compound adopts a half-chair conformation. The amide N atom lies almost in the plane defined by the three neighbouring C atoms. In the crystal structure, molecules are linked by weak intermolecular C-H...O and C-H...pi hydrogen bonds.

  15. A phosphatidylinositol lipids system, lamellipodin, and Ena/VASP regulate dynamic morphology of multipolar migrating cells in the developing cerebral cortex.

    PubMed

    Yoshinaga, Satoshi; Ohkubo, Takahiro; Sasaki, Shinji; Nuriya, Mutsuo; Ogawa, Yukino; Yasui, Masato; Tabata, Hidenori; Nakajima, Kazunori

    2012-08-22

    In the developing mammalian cerebral cortex, excitatory neurons are generated in the ventricular zone (VZ) and subventricular zone; these neurons migrate toward the pial surface. The neurons generated in the VZ assume a multipolar morphology and remain in a narrow region called the multipolar cell accumulation zone (MAZ) for ∼24 h, in which they extend and retract multiple processes dynamically. They eventually extend an axon tangentially and begin radial migration using a migratory mode called locomotion. Despite the potential biological importance of the process movement of multipolar cells, the molecular mechanisms remain to be elucidated. Here, we observed that the processes of mouse multipolar cells were actin rich and morphologically resembled the filopodia and lamellipodia in growth cones; thus, we focused on the actin-remodeling proteins Lamellipodin (Lpd) and Ena/vasodilator-stimulated phosphoprotein (VASP). Lpd binds to phosphatidylinositol (3,4)-bisphosphate [PI(3,4)P₂] and recruits Ena/VASP, which promotes the assembly of actin filaments, to the plasma membranes. In situ hybridization and immunohistochemistry revealed that Lpd is expressed in multipolar cells in the MAZ. The functional silencing of either Lpd or Ena/VASP decreased the number of primary processes. Immunostaining and a Förster resonance energy transfer analysis revealed the subcellular localization of PI(3,4)P₂ at the tips of the processes. A knockdown experiment and treatment with an inhibitor for Src homology 2-containing inositol phosphatase-2, a 5-phosphatase that produces PI(3,4)P₂ from phosphatidylinositol (3,4,5)-triphosphate, decreased the number of primary processes. Our observations suggest that PI(3,4)P₂, Lpd, and Ena/VASP are involved in the process movement of multipolar migrating cells.

  16. Corneal endothelial cells possess an elaborate multipolar shape to maximize the basolateral to apical membrane area

    PubMed Central

    Harrison, Theresa A.; He, Zhiguo; Boggs, Kristin; Thuret, Gilles; Liu, Hong-Xiang

    2016-01-01

    . Conclusions Our analysis indicates that, far from being simple polygonal prisms, endothelial cells possess an elaborate multipolar shape. Their unusual geometry may be essential for the endothelium to carry out its role as the principal regulator of corneal extracellular fluid flux, and thus ultimately of tissue clarity. PMID:27081293

  17. Multipolar electrostatics based on the Kriging machine learning method: an application to serine.

    PubMed

    Yuan, Yongna; Mills, Matthew J L; Popelier, Paul L A

    2014-04-01

    A multipolar, polarizable electrostatic method for future use in a novel force field is described. Quantum Chemical Topology (QCT) is used to partition the electron density of a chemical system into atoms, then the machine learning method Kriging is used to build models that relate the multipole moments of the atoms to the positions of their surrounding nuclei. The pilot system serine is used to study both the influence of the level of theory and the set of data generator methods used. The latter consists of: (i) sampling of protein structures deposited in the Protein Data Bank (PDB), or (ii) normal mode distortion along either (a) Cartesian coordinates, or (b) redundant internal coordinates. Wavefunctions for the sampled geometries were obtained at the HF/6-31G(d,p), B3LYP/apc-1, and MP2/cc-pVDZ levels of theory, prior to calculation of the atomic multipole moments by volume integration. The average absolute error (over an independent test set of conformations) in the total atom-atom electrostatic interaction energy of serine, using Kriging models built with the three data generator methods is 11.3 kJ mol⁻¹ (PDB), 8.2 kJ mol⁻¹ (Cartesian distortion), and 10.1 kJ mol⁻¹ (redundant internal distortion) at the HF/6-31G(d,p) level. At the B3LYP/apc-1 level, the respective errors are 7.7 kJ mol⁻¹, 6.7 kJ mol⁻¹, and 4.9 kJ mol⁻¹, while at the MP2/cc-pVDZ level they are 6.5 kJ mol⁻¹, 5.3 kJ mol⁻¹, and 4.0 kJ mol⁻¹. The ranges of geometries generated by the redundant internal coordinate distortion and by extraction from the PDB are much wider than the range generated by Cartesian distortion. The atomic multipole moment and electrostatic interaction energy predictions for the B3LYP/apc-1 and MP2/cc-pVDZ levels are similar, and both are better than the corresponding predictions at the HF/6-31G(d,p) level.

  18. Excitatory cortical neurons with multipolar shape establish neuronal polarity by forming a tangentially oriented axon in the intermediate zone.

    PubMed

    Hatanaka, Yumiko; Yamauchi, Kenta

    2013-01-01

    The formation of axon-dendrite polarity is crucial for neuron to make the proper information flow within the brain. Although the processes of neuronal polarity formation have been extensively studied using neurons in dissociated culture, the corresponding developmental processes in vivo are still unclear. Here, we illuminate the initial steps of morphological polarization of excitatory cortical neurons in situ, by sparsely labeling their neuroepithelial progenitors using in utero electroporation and then examining their neuronal progeny in brain sections and in slice cultures. Morphological analysis showed that an axon-like long tangential process formed in progeny cells in the intermediate zone (IZ). Time-lapse imaging analysis using slice culture revealed that progeny cells with multipolar shape, after alternately extending and retracting their short processes for several hours, suddenly elongated a long process tangentially. These cells then transformed into a bipolar shape, extending a pia-directed leading process, and migrated radially leaving the tangential process behind, which gave rise to an "L-shaped" axon. Our findings suggest that neuronal polarity in these cells is established de novo from a nonpolarized stage in vivo and indicate that excitatory cortical neurons with multipolar shape in the IZ initiate axon outgrowth before radial migration into the cortical plate.

  19. Application of multipolar charge models and molecular dynamics simulations to study stark shifts in inhomogeneous electric fields.

    PubMed

    Devereux, Michael; Plattner, Nuria; Meuwly, Markus

    2009-11-26

    Atomic multipole moments are used to investigate vibrational frequency shifts of CO and H(2) in uniform and inhomogeneous electric fields using ab initio calculations and Molecular Dynamics (MD) simulations. The importance of using atomic multipole moments that can accurately represent both molecular electrostatics and the vibrational response of the molecule to changes in the local electric field is highlighted. The vibrational response of CO to applied uniform and inhomogeneous electric fields is examined using Density Functional Theory calculations for a range of test fields, and the results are used to assess the performance of different atomic multipole models. In uniform fields, the calculated Stark tuning rates of Deltamu = 0.52 cm(-1)/(MV/cm) (DFT), Deltamu = 0.55 cm(-1)/(MV/cm) (fluctuating three-point charge model), and Deltamu = 0.64 cm(-1)/(MV/cm) (Multipole model up to octupole), compare favorably with the experimentally measured value of 0.67 cm(-1)/(MV/cm). For H(2), which has no permanent dipole moment, CCSD(T) calculations demonstrate the importance of bond-weakening effects in force fields in response to the applied inhomogeneous electric field. Finally, CO in hexagonal ice is considered as a test system to highlight the performance of selected multipolar models in MD simulations. The approach discussed here can be applied to calibrate a range of multipolar charge models for diatomic probes, with applications to interpret Stark spectroscopy measurements in protein active sites.

  20. Dependence of the probabilities of the electric-multipole electron transitions in W{sup 24+} on multipolarity

    SciTech Connect

    Gaigalas, Gediminas; Rudzikas, Zenonas; Rynkun, Pavel; Alkauskas, Andrius

    2011-03-15

    Usually it is accepted that the probabilities of the electric-multipole electron transitions are rapidly decreasing functions of their multipolarity. Therefore while calculating the probabilities of electronic transitions between the configurations of certain chosen parities, it seems sufficient to take into account the first nonzero term, i.e., to consider the electron transitions of lowest multipolarity permitted by the exact selection rules. This paper aims at verifying this assumption on the example of electric-octupole transitions in W{sup 24+} ion. For this purpose the large-scale multiconfiguration Hartree-Fock and Dirac-Fock calculations have been performed for the configurations [Kr]4d{sup 10}4f{sup 4} and [Kr]4d{sup 10}4f{sup 3}5s energy levels of W{sup 24+} ion. The relativistic corrections were taken into account in the quasirelativistic Breit-Pauli and fully relativistic Breit (taking into account QED effects) approximations. The role of correlation, relativistic, and QED corrections is discussed. Line strengths, oscillator strengths, and transition probabilities in Coulomb and Babushkin gauges are presented for E1 and E3 transitions among these levels.

  1. Comparative analysis of transverse intrafascicular multichannel, longitudinal intrafascicular and multipolar cuff electrodes for the selective stimulation of nerve fascicles

    NASA Astrophysics Data System (ADS)

    Badia, Jordi; Boretius, Tim; Andreu, David; Azevedo-Coste, Christine; Stieglitz, Thomas; Navarro, Xavier

    2011-06-01

    The selection of a suitable nerve electrode for neuroprosthetic applications implies a trade-off between invasiveness and selectivity, wherein the ultimate goal is achieving the highest selectivity for a high number of nerve fascicles by the least invasiveness and potential damage to the nerve. The transverse intrafascicular multichannel electrode (TIME) is intended to be transversally inserted into the peripheral nerve and to be useful to selectively activate subsets of axons in different fascicles within the same nerve. We present a comparative study of TIME, LIFE and multipolar cuff electrodes for the selective stimulation of small nerves. The electrodes were implanted on the rat sciatic nerve, and the activation of gastrocnemius, plantar and tibialis anterior muscles was recorded by EMG signals. Thus, the study allowed us to ascertain the selectivity of stimulation at the interfascicular and also at the intrafascicular level. The results of this study indicate that (1) intrafascicular electrodes (LIFE and TIME) provide excitation circumscribed to the implanted fascicle, whereas extraneural electrodes (cuffs) predominantly excite nerve fascicles located superficially; (2) the minimum threshold for muscle activation with TIME and LIFE was significantly lower than with cuff electrodes; (3) TIME allowed us to selectively activate the three tested muscles when stimulating through different active sites of one device, both at inter- and intrafascicular levels, whereas selective activation using multipolar cuff (with a longitudinal tripolar stimulation configuration) was only possible for two muscles, at the interfascicular level, and LIFE did not activate selectively more than one muscle in the implanted nerve fascicle.

  2. Hippocampal pyramidal neurons switch from a multipolar migration mode to a novel "climbing" migration mode during development.

    PubMed

    Kitazawa, Ayako; Kubo, Ken-ichiro; Hayashi, Kanehiro; Matsunaga, Yuki; Ishii, Kazuhiro; Nakajima, Kazunori

    2014-01-22

    The hippocampus plays important roles in brain functions. Despite the importance of hippocampal functions, recent analyses of neuronal migration have mainly been performed on the cerebral neocortex, and the cellular mechanisms responsible for the formation of the hippocampus are not yet completely understood. Moreover, why a prolonged time is required for hippocampal neurons to complete their migration has been unexplainable for several decades. We analyzed the migratory profile of neurons in the developing mouse hippocampal CA1 region and found that the hippocampal pyramidal neurons generated near the ventricle became postmitotic multipolar cells and accumulated in the multipolar cell accumulation zone (MAZ) in the late stage of development. The hippocampal neurons passed through the pyramidal layer by a unique mode of migration. Their leading processes were highly branched and made contact with many radial fibers. Time-lapse imaging revealed that the migrating cells changed their scaffolds from the original radial fibers to other radial fibers, and as a result they proceed in a zigzag manner, with long intervals. The migrating cells in the hippocampus reminded us of "rock climbers" that instead of using their hands to pull up their bodies were using their leading processes to pull up their cell bodies. Because this mode of migration had never been described, we called it the "climbing" mode. The change from the "climbing" mode in the hippocampus to the "locomotion" mode in the neocortex may have contributed to the brain expansion during evolution.

  3. NDUFV2 regulates neuronal migration in the developing cerebral cortex through modulation of the multipolar-bipolar transition.

    PubMed

    Chen, Tianda; Wu, Qinwei; Zhang, Yang; Zhang, Dai

    2015-11-02

    Abnormalities during brain development are tightly linked several psychiatric disorders. Mutations in NADH dehydrogenase ubiquinone flavoprotein 2 (NDUFV2) are responsible for schizophrenia, bipolar disorder and Parkinson׳s disease. However, the function of NDUFV2 during brain development remains unclear. Here we reported that ndufv2 is expressed in the developing cerebral cortex. In utero suppression of ndufv2 arrested neuronal migration, leading to accumulation of ectopic neurons in the intermediate zone. ndufv2 inhibition did not affect radial glia scaffold, progenitor cells or neurons survival. However, the loss of ndufv2 impairs neuronal multipolar-bipolar transition in vivo and polarization in vitro. Moreover, ndufv2 affected actin cytoskeleton and tubulin stabilization in cortical neurons. Overall, our findings establish a new NDUFV2 dependent mechanism underlying neuronal migration and psychiatric disorders.

  4. Multipolar theory of blackbody radiation shift of atomic energy levels and its implications for optical lattice clocks

    SciTech Connect

    Porsev, Sergey G.; Derevianko, Andrei

    2006-08-15

    Blackbody radiation (BBR) shifts of the {sup 3}P{sub 0}-{sup 1}S{sub 0} clock transition in the divalent atoms Mg, Ca, Sr, and Yb are evaluated. The dominant electric-dipole contributions are computed using accurate relativistic many-body techniques of atomic structure. At room temperatures, the resulting uncertainties in the E1 BBR shifts are large and substantially affect the projected 10{sup -18} fractional accuracy of the optical-lattice-based clocks. A peculiarity of these clocks is that the characteristic BBR wavelength is comparable to the {sup 3}P fine-structure intervals. To evaluate relevant M1 and E2 contributions, a theory of multipolar BBR shifts is developed. The resulting corrections, although presently masked by the uncertainties in the E1 contribution, are required at the 10{sup -18} accuracy goal.

  5. Increase of intracellular Ca2+ by P2Y but not P2X receptors in cultured cortical multipolar neurons of the rat.

    PubMed

    Fischer, Wolfgang; Nörenberg, Wolfgang; Franke, Heike; Schaefer, Michael; Illes, Peter

    2009-10-10

    The expression and functionality of P2X/P2Y receptor subtypes in multipolar nonpyramidal neurons of mixed cortical cell cultures were investigated by means of immunocytochemistry and fura-2 microfluorimetry. The morphological studies revealed that most of the neurons are immunoreactive for GABA and express a range of P2X/P2Y receptors, predominantly of the P2X(2,4,6) and P2Y(1,2) subtypes. P2X(1) and P2X(7) receptor immunoreactivity (IR) was found on thin axon-like processes and presynaptic structures, respectively. Application of ATP caused a small concentration-dependent increase in intracellular Ca2+ concentration ([Ca2+]i) in most investigated neurons, whereas only about the half of these cells responded to 2',3'-O-(benzoyl-4-benzoyl)-ATP (BzATP), ADPbetaS, 2MeSADP, or 2MeSATP and even fewer cells to UTP. In contrast, alpha,beta-meATP, UDP, and UDP-glucose failed to produce any [Ca2+]i signaling. The response to ATP itself was inhibited by pyridoxal-5'-phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS), Reactive Blue 2, 2'-deoxy-N(6)-methyl adenosine 3',5'-diphosphate (MRS2179), and suramin (300 microM) as well as by a cyclopiazonic acid-induced depletion of intracellular Ca2+ stores. A Ca2+-free external medium tended to decrease the ATP-induced [Ca2+]i transients, although this action did not reach statistical significance. Various blockers of voltage-sensitive Ca2+ channels and the gap junction inhibitor carbenoxolone did not interfere with the effect of ATP, whereas a combination of the ionotropic glutamate receptor antagonists D(-)-2-amino-5-phosphonopentanoic acid (AP5) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) decreased it. Cross-desensitization experiments between ADPbetaS or UTP and ATP suggested that ATP acts on the one hand via P2Y(1,2) receptors and on the other hand by additional signaling mechanisms. These mechanisms may involve the release of glutamate (which in consequence activates ionotropic glutamate receptors) and the entry of Ca2

  6. The 5'-flanking region of the RP58 coding sequence shows prominent promoter activity in multipolar cells in the subventricular zone during corticogenesis.

    PubMed

    Ohtaka-Maruyama, C; Hirai, S; Miwa, A; Takahashi, A; Okado, H

    2012-01-10

    Pyramidal neurons of the neocortex are produced from progenitor cells located in the neocortical ventricular zone (VZ) and subventricular zone (SVZ) during embryogenesis. RP58 is a transcriptional repressor that is strongly expressed in the developing brain and plays an essential role in corticogenesis. The expression of RP58 is strictly regulated in a time-dependent and spatially restricted manner. It is maximally expressed in E15-16 embryonic cerebral cortex, localized specifically to the cortical plate and SVZ of the neocortex, hippocampus, and parts of amygdala during brain development, and found in glutamatergic but not GABAergic neurons. Identification of the promoter activity underlying specific expression patterns provides important clues to their mechanisms of action. Here, we show that the RP58 gene promoter is activated prominently in multipolar migrating cells, the first in vivo analysis of RP58 promoter activity in the brain. The 5.3 kb 5'-flanking genomic DNA of the RP58 coding region demonstrates promoter activity in neurons both in vitro and in vivo. This promoter is highly responsive to the transcription factor neurogenin2 (Ngn2), which is a direct upstream activator of RP58 expression. Using in utero electroporation, we demonstrate that RP58 gene promoter activity is first detected in a subpopulation of pin-like VZ cells, then prominently activated in migrating multipolar cells in the multipolar cell accumulation zone (MAZ) located just above the VZ. In dissociated primary cultured cortical neurons, RP58 promoter activity mimics in vivo expression patterns from a molecular standpoint that RP58 is expressed in a fraction of Sox2-positive progenitor cells, Ngn2-positive neuronal committed cells, and Tuj1-positive young neurons, but not in Dlx2-positive GABAergic neurons. Finally, we show that Cre recombinase expression under the control of the RP58 gene promoter is a feasible tool for conditional gene switching in post-mitotic multipolar migrating

  7. [Modulating effect of dopamine on amplitude of GABA-produced chemocontrolled currents in multipolar spinal cord neurons of ammocaete].

    PubMed

    Bukinich, A A

    2010-01-01

    By using the patch-clamp method in the whole cell configuration, modulating effect of dopamine on GABA-activated currents has been studied on isolated multipolar spinal cord neurons of the ammocaete (larva of the lamprey Lampetra planeri). At application of dopamine (5 microM), there was observed in some cases a decrease of the GABA-activated current, on average, by 33.3 +/- 8.7 (n = 8, p < 0.01), in other cases--an increase of the amplitude, on average, by 37.3 +/- 11.8% (n = 5, p < 0.01). Concentration of GABA amounted to 2 mM. Study of action of agonists of D1- and D2-receptors on amplitude of che-mocontrolled currents has shown that agonist of D1-receptors (+)-SKF-38393 (5 microM) decreases the GABA-activated current amplitude, on average, by 63.1 +/- 11.7% (n = 8, p < 0.01); the agonist of D2-receptors (-)-quinpirole (5 microM) produces in various cells the dopamine-like effects: an increase of the GABA-activated current amplitude, on average, by 61.0 +/- 13.8% (n = 8, p < 0.01) and a decrease of amplitude, on average, by 55.7 +/- 2.0 % (n = 6, p < 0.01). It has been shown that antagonist of D2-receptors sulpiride (5 microM) does not block effects produced by dopamine. The dopamine effects were partially blocked by antagonist of D1-receptors (+)-SCH-23390 (5 microM): a decrease of the GABA-activated amplitude current amounted, on average, to 11.7 +/- 1.8 % (n = 7, p < 0.01), while an increase of amplitude--8.3 +/- 2.0 % (n = 5,p < 0.01). At the same time, effects of agonist of D1-receptors quinpirole (5 microM) were partially blocked by antagonist of D1-receptors (+)-SCH-23390: a decrease of the GABA-activated current amplitude amounted, on average, to 9.2 +/- 3.4 % (n = 6, p < 0.01) and an increase of amplitude--6.3 +/- 1.8 % (n = 10, p < 0.01). The obtained data indicate differences of mechanisms of the receptor-mediated effect of agonists of dopamine receptors on GABA-activated and potential-activated currents of multipolar neurons of the ammocaete spinal

  8. The development and migration of large multipolar neurons into the cochlear nucleus of the North American opossum.

    PubMed

    Willard, F H; Martin, G F

    1986-06-01

    We have studied the maturation of the inferior colliculus and cochlear nuclei of the North American opossum with particular emphasis on the large multipolar neurons of the cochlear nucleus. These neurons include the principal and giant cells of the dorsal cochlear nucleus (DCN) and the large neurons of the ventral cochlear nucleus (VCN), all of which can be labelled by horseradish peroxidase (HRP) injections into the contralateral inferior colliculus (IC). The size of these neurons, their characteristic Nissl patterns, and their labelling density after injections into the IC render them distinguishable from other neurons in this nuclei, even in young animals. In Nissl-stained sections of newborn opossums, a band of horizontally oriented neurons can be identified dorsomedial to the vestibular nerve root. This band extends from an apparent cytogenetic zone close to the sulcus limitans, to, but not within, the presumptive cochlear nucleus. Between birth and estimated postnatal day 22 (EPND 22) the band shifts laterally, eventually becoming incorporated into the cochlear nucleus. Many neurons in this band have perinuclear caps of Nissl substance similar to those present in the principal cells of the adult DCN. Injections of HRP into the IC as early as EPND 5 (17 days after conception) labelled neurons in the band referred to above but not in the presumptive cochlear nucleus. By EPND 15, labelled cells were clustered mainly within the nucleus proper. Most of these cells were located in the DCN, but a few were scattered in the dorsocentral VCN. Consistent labelling of small neurons in VCN was not obtained until sometime later. From EPND 15 to EPND 20 most of the labelled cells in DCN reoriented in the vertical plane, aligned in layer II, and differentiated into principal neurons. Some, however, remained deep to layer II and differentiated into giant neurons. The heavily labelled cells in VCN differentiated into large neurons. Our results suggest that the large multipolar

  9. WAVE2-Abi2 complex controls growth cone activity and regulates the multipolar-bipolar transition as well as the initiation of glia-guided migration.

    PubMed

    Xie, Min-Jue; Yagi, Hideshi; Kuroda, Kazuki; Wang, Chen-Chi; Komada, Munekazu; Zhao, Hong; Sakakibara, Akira; Miyata, Takaki; Nagata, Koh-Ichi; Oka, Yuichiro; Iguchi, Tokuichi; Sato, Makoto

    2013-06-01

    Glia-guided migration (glia-guided locomotion) during radial migration is a characteristic yet unique mode of migration. In this process, the directionality of migration is predetermined by glial processes and not by growth cones. Prior to the initiation of glia-guided migration, migrating neurons transform from multipolar to bipolar, but the molecular mechanisms underlying this multipolar-bipolar transition and the commencement of glia-guided migration are not fully understood. Here, we demonstrate that the multipolar-bipolar transition is not solely a cell autonomous event; instead, the interaction of growth cones with glial processes plays an essential role. Time-lapse imaging with lattice assays reveals the importance of vigorously active growth cones in searching for appropriate glial scaffolds, completing the transition, and initiating glia-guided migration. These growth cone activities are regulated by Abl kinase and Cdk5 via WAVE2-Abi2 through the phosphorylation of tyrosine 150 and serine 137 of WAVE2. Neurons that do not display such growth cone activities are mispositioned in a more superficial location in the neocortex, suggesting the significance of growth cones for the final location of the neurons. This process occurs in spite of the "inside-out" principle in which later-born neurons are situated more superficially.

  10. Numerical simulation and performance improvement of a multi-polar concentric Halbach cylindrical magnet for magnetic refrigeration

    NASA Astrophysics Data System (ADS)

    You, Yonghua; Guo, Yue; Xiao, Shuifang; Yu, Shen; Ji, Hu; Luo, Xiaobing

    2016-05-01

    Multi-polar concentric Halbach cylinders of magnets could generate the magnetic field varying considerably in the annular gaps, thus were applied in the rotary magnetic refrigerators. In the current investigation, a six-polar concentric Halbach cylinder is developed based on the ideal concentric one by the numerical simulation with COMSOL Multiphysics. Cylinder radii are optimized and magnet material profiles are adjusted for a better overall performance (Λcool). Moreover, the segmentation on the concentric cylinder is conducted for an easy fabrication, and the edge effect of finite-length device is studied. With the present investigation, it is found that a larger external radius of external cylinder facilitates a larger flux density in the high field region (| B | bar high), while Λcool could be worse. Meanwhile, with the removal of magnet materials enclosed by the equipotential lines of magnetic vector potential, the magnetic flux density in low field region (| B | bar low) drops from 0.271 to 0.0136 T, and Λcool rises from 1.36 to 1.85 T0.7. Moreover, a proper segmentation would not degrade the difference between | B | bar high and | B | bar low, on the contrary, Λcool rises by about 20.2% due to magnet materials lack for efficiency replaced by soft irons. Finally, current 3D simulation indicates the edge effect on Λcool could be trivial.

  11. Automated Wetland Delineation from Multi-Frequency and Multi-Polarized SAR Images in High Temporal and Spatial Resolution

    NASA Astrophysics Data System (ADS)

    Moser, L.; Schmitt, A.; Wendleder, A.

    2016-06-01

    Water scarcity is one of the main challenges posed by the changing climate. Especially in semi-arid regions where water reservoirs are filled during the very short rainy season, but have to store enough water for the extremely long dry season, the intelligent handling of water resources is vital. This study focusses on Lac Bam in Burkina Faso, which is the largest natural lake of the country and of high importance for the local inhabitants for irrigated farming, animal watering, and extraction of water for drinking and sanitation. With respect to the competition for water resources an independent area-wide monitoring system is essential for the acceptance of any decision maker. The following contribution introduces a weather and illumination independent monitoring system for the automated wetland delineation with a high temporal (about two weeks) and a high spatial sampling (about five meters). The similarities of the multispectral and multi-polarized SAR acquisitions by RADARSAT-2 and TerraSAR-X are studied as well as the differences. The results indicate that even basic approaches without pre-classification time series analysis or post-classification filtering are already enough to establish a monitoring system of prime importance for a whole region.

  12. Accuracy and tractability of a kriging model of intramolecular polarizable multipolar electrostatics and its application to histidine.

    PubMed

    Kandathil, Shaun M; Fletcher, Timothy L; Yuan, Yongna; Knowles, Joshua; Popelier, Paul L A

    2013-08-05

    We propose a generic method to model polarization in the context of high-rank multipolar electrostatics. This method involves the machine learning technique kriging, here used to capture the response of an atomic multipole moment of a given atom to a change in the positions of the atoms surrounding this atom. The atoms are malleable boxes with sharp boundaries, they do not overlap and exhaust space. The method is applied to histidine where it is able to predict atomic multipole moments (up to hexadecapole) for unseen configurations, after training on 600 geometries distorted using normal modes of each of its 24 local energy minima at B3LYP/apc-1 level. The quality of the predictions is assessed by calculating the Coulomb energy between an atom for which the moments have been predicted and the surrounding atoms (having exact moments). Only interactions between atoms separated by three or more bonds ("1, 4 and higher" interactions) are included in this energy error. This energy is compared with that of a central atom with exact multipole moments interacting with the same environment. The resulting energy discrepancies are summed for 328 atom-atom interactions, for each of the 29 atoms of histidine being a central atom in turn. For 80% of the 539 test configurations (outside the training set), this summed energy deviates by less than 1 kcal mol(-1).

  13. The vapor-liquid interface potential of (multi)polar fluids and its influence on ion solvation.

    PubMed

    Horváth, Lorand; Beu, Titus; Manghi, Manoel; Palmeri, John

    2013-04-21

    The interface between the vapor and liquid phase of quadrupolar-dipolar fluids is the seat of an electric interfacial potential whose influence on ion solvation and distribution is not yet fully understood. To obtain further microscopic insight into water specificity we first present extensive classical molecular dynamics simulations of a series of model liquids with variable molecular quadrupole moments that interpolates between SPC/E water and a purely dipolar liquid. We then pinpoint the essential role played by the competing multipolar contributions to the vapor-liquid and the solute-liquid interface potentials in determining an important ion-specific direct electrostatic contribution to the ionic solvation free energy for SPC/E water-dominated by the quadrupolar and dipolar parts-beyond the dominant polarization one. Our results show that the influence of the vapor-liquid interfacial potential on ion solvation is strongly reduced due to the strong partial cancellation brought about by the competing solute-liquid interface potential.

  14. Multipolar phases and magnetically hidden order: review of the heavy-fermion compound Ce1-x La x B6.

    PubMed

    Cameron, Alistair S; Friemel, Gerd; Inosov, Dmytro S

    2016-06-01

    Cerium hexaboride is a cubic f-electron heavy-fermion compound that displays a rich array of low-temperature magnetic ordering phenomena which have been the subject of investigation for more than 50 years. Its complex behaviour is the result of competing interactions, with both itinerant and local electrons playing important roles. Investigating this material has proven to be a substantial challenge, in particular because of the appearance of a 'magnetically hidden order' phase, which remained elusive to neutron-scattering investigations for many years. It was not until the development of modern x-ray scattering techniques that the long suspected multipolar origin of this phase was confirmed. Doping with non-magnetic lanthanum dilutes the magnetic cerium sublattice and reduces the f-electron count, bringing about substantial changes to the ground state with the emergence of new phases and quantum critical phenomena. To this day, Ce1-x La x B6 and its related compounds remain a subject of intense interest. Despite the substantial progress in understanding their behaviour, they continue to reveal new and unexplained physical phenomena. Here we present a review of the accumulated body of knowledge on this family of materials in order to provide a firm standpoint for future investigations.

  15. Tetraploid cells from cytokinesis failure induce aneuploidy and spontaneous transformation of mouse ovarian surface epithelial cells.

    PubMed

    Lv, Lei; Zhang, Tianwei; Yi, Qiyi; Huang, Yun; Wang, Zheng; Hou, Heli; Zhang, Huan; Zheng, Wei; Hao, Qiaomei; Guo, Zongyou; Cooke, Howard J; Shi, Qinghua

    2012-08-01

    Most ovarian cancers originate from the ovarian surface epithelium and are characterized by aneuploid karyotypes. Aneuploidy, a consequence of chromosome instability, is an early event during the development of ovarian cancers. However, how aneuploid cells are evolved from normal diploid cells in ovarian cancers remains unknown. In the present study, cytogenetic analyses of a mouse syngeneic ovarian cancer model revealed that diploid mouse ovarian surface epithelial cells (MOSECs) experienced an intermediate tetraploid cell stage, before evolving to aneuploid (mainly near-tetraploid) cells. Using long-term live-cell imaging followed by fluorescence in situ hybridization (FISH), we demonstrated that tetraploid cells originally arose from cytokinesis failure of bipolar mitosis in diploid cells, and gave rise to aneuploid cells through chromosome mis-segregation during both bipolar and multipolar mitoses. Injection of the late passage aneuploid MOSECs resulted in tumor formation in C57BL/6 mice. Therefore, we reveal a pathway for the evolution of diploid to aneuploid MOSECs and elucidate a mechanism for the development of near-tetraploid ovarian cancer cells.

  16. Cdk5 is required for multipolar-to-bipolar transition during radial neuronal migration and proper dendrite development of pyramidal neurons in the cerebral cortex.

    PubMed

    Ohshima, Toshio; Hirasawa, Motoyuki; Tabata, Hidenori; Mutoh, Tetsuji; Adachi, Tomoko; Suzuki, Hiromi; Saruta, Keiko; Iwasato, Takuji; Itohara, Shigeyoshi; Hashimoto, Mistuhiro; Nakajima, Kazunori; Ogawa, Masaharu; Kulkarni, Ashok B; Mikoshiba, Katsuhiko

    2007-06-01

    The mammalian cerebral cortex consists of six layers that are generated via coordinated neuronal migration during the embryonic period. Recent studies identified specific phases of radial migration of cortical neurons. After the final division, neurons transform from a multipolar to a bipolar shape within the subventricular zone-intermediate zone (SVZ-IZ) and then migrate along radial glial fibres. Mice lacking Cdk5 exhibit abnormal corticogenesis owing to neuronal migration defects. When we introduced GFP into migrating neurons at E14.5 by in utero electroporation, we observed migrating neurons in wild-type but not in Cdk5(-/-) embryos after 3-4 days. Introduction of the dominant-negative form of Cdk5 into the wild-type migrating neurons confirmed specific impairment of the multipolar-to-bipolar transition within the SVZ-IZ in a cell-autonomous manner. Cortex-specific Cdk5 conditional knockout mice showed inverted layering of the cerebral cortex and the layer V and callosal neurons, but not layer VI neurons, had severely impaired dendritic morphology. The amount of the dendritic protein Map2 was decreased in the cerebral cortex of Cdk5-deficient mice, and the axonal trajectory of cortical neurons within the cortex was also abnormal. These results indicate that Cdk5 is required for proper multipolar-to-bipolar transition, and a deficiency of Cdk5 results in abnormal morphology of pyramidal neurons. In addition, proper radial neuronal migration generates an inside-out pattern of cerebral cortex formation and normal axonal trajectories of cortical pyramidal neurons.

  17. Multipolarity analysis for {sup 14}C high-energy resonance populated by ({sup 18}O,{sup 16}O) two-neutron transfer reaction

    SciTech Connect

    Carbone, D. Cavallaro, M.; Bondì, M.; Agodi, C.; Cunsolo, A.; Cappuzzello, F.; Azaiez, F.; Franchoo, S.; Khan, E.; Bonaccorso, A.; Fortunato, L.; Foti, A.; Linares, R.; Lubian, J.; Scarpaci, J. A.; Vitturi, A.

    2015-10-15

    The {sup 12}C({sup 18}O,{sup 16}O){sup 14}C reaction at 84 MeV incident energy has been explored up to high excitation energy of the residual nucleus thanks to the use of the MAGNEX spectrometer to detect the ejectiles. In the region above the two-neutron separation energy, a resonance has been observed at 16.9 MeV. A multipolarity analysis of the cross section angular distribution indicates an L = 0 character for such a transition.

  18. Establishment of M1 multipolarity of a 6.5 (micro)2n resonance in 172Yb at E(gamma) = 3.3 MeV

    SciTech Connect

    Schiller, A; Voinov, A; Algin, E; Becker, J A; Bernstein, L A; Garrett, P E; Guttormsen, M; Nelson, R O; Rekstad, J; Siem, S

    2004-02-04

    Two-step-cascade spectra in {sup 172}Yb have been measured after thermal neutron capture. they are compared to calculations based on experimental values of the level density and radiative strength function (RSF) obtained from the {sup 173}Yb(3{sup 3}He,{alpha}{gamma}){sup 172}Yb reaction. The multipolarity of a 6.5(15) {mu}{sub N}{sup 2} resonance at E{sub {gamma}} = 3.3(1) MeV in the RSF is determined to be M1 by this comparison.

  19. 5-(3,4-Dimethoxybenzyl)-7-isopropyl-1,3,5-triazepane-2,6-dione acetonitrile solvate refined using a multipolar atom model.

    PubMed

    Ejsmont, Krzysztof; Boeglin, Joel; Didierjean, Claude; Guichard, Gilles; Jelsch, Christian

    2010-06-01

    The crystal structure of the title compound, C(16)H(23)N(3)O(4).CH(3)CN, was refined using a multipolar atom model transferred from an experimental electron-density database. The refinement showed some improvement in crystallographic statistical indices compared with the independent atom model. The triazepane ring adopts a twist-boat conformation. In the crystal structure, the molecule forms intermolecular contacts with 14 different neighbours. There are two N-H...O and one C-H...O intermolecular hydrogen bond.

  20. Genetic changes induced by space flight factors in barley seeds on Soyuz-5 and Soyuz-9 craft

    NASA Technical Reports Server (NTRS)

    Nuzhdin, N. I.; Dozortseva, R. L.

    1980-01-01

    Air-dry seeds of the barley Zimujuschij moscowskyi of the 1969 harvest were taken into space onboard the spaceships Soyuz-5 and Soyuz-9. A cytological study of the mitoses in meristemic cells in rootlet terminals revealed that space flight factors (SFF) in nonirradiated seeds induced about 3% of aberrant cells. After irradiation the effect of SFF increased over two-fold. Although the radio protectors ensured the seeds against from the SFF-induced damage either in irradiated or nonirradiated seed cells which is inconsistent with the previously obtained data.

  1. [Peculiarities of dopamine receptors on the membrane of spinal cord multipolar neurons of the brook lamprey Lampetra planeri].

    PubMed

    Bukinich, A a; Tsvetkov, E A; Veselkin, N P

    2007-01-01

    On isolated multiporal neurons of spinal cord of amniocoete larva of the brook lamprey Lampetra planeri, by the patch-clamp method in configuration "the whole cell", a modulating effect of dopamine on potential-activated Na+ currents was studied. Application of dopamine (10 microM) was shown to produce a complex action on the sodium current amplitude. In some cases a decrease of the amplitude, on average, by 13.5 +/- 2.2% was found, while in others--an increase, on average, by 8.6 +/- 6.1%. The modulation dopamine effect was not accompanied by any changes either of the threshold of the current appearance or of resistance of neuronal cell membranes. Pharmacological analysis with use of dopamine agonist has shown that the agonist of D1-receptors (-)-SKF-38393 (10 microM) decreases the Na+ current amplitude, whereas the agonist of D2-receptors (-)-quinpirole (10 microM) can produce in different cells both an increase, by 30.7 +/- 17.0 %, and a decrease, by 13.2 +/- 3.1%, of the Na+ current amplitude. The obtained data indicate the existence of D1- and D2-receptors on the membrane of multipolar spinal neurons of the amniocoete larva of the brook lamprey. Study of action of antagonists has shown that the antagonist of D1-receptors (+)-SCH-23390 (10 microM) does not affect action of the agonist of D1-receptors (-)-SKF-38393 (10 microM); the antagonist of D2-receptors (-)-sulpiride (10 microM) blocks completely effects both of the agonist of D1-receptors (-)-SKF-38393 (10 microM) and of the agonist of D2-receptors (-)-quinpirole (10 microM). The antagonist of D1-receptors (+)-SCH-23390 (10 microM) produced no effect on action of the agonist of D1-receptors (-)-SKF-38393 (10 microM). The obtained data indicate peculiarities of dopamine receptors of Cyclostomata as compared with those in mammals.

  2. General methodology to optimize damping functions to account for charge penetration effects in electrostatic calculations using multicentered multipolar expansions.

    PubMed

    Werneck, Araken S; Filho, Tarcísio M Rocha; Dardenne, Laurent E

    2008-01-17

    We developed a methodology to optimize exponential damping functions to account for charge penetration effects when computing molecular electrostatic properties using the multicentered multipolar expansion method (MME). This methodology is based in the optimization of a damping parameter set using a two-step fast local fitting procedure and the ab initio (Hartree-Fock/6-31G** and 6-31G**+) electrostatic potential calculated in a set of concentric grid of points as reference. The principal aspect of the methodology is a first local fitting step which generates a focused initial guess to improve the performance of a simplex method avoiding the use of multiple runs and the choice of initial guesses. Three different strategies for the determination of optimized damping parameters were tested in the following studies: (1) investigation of the error in the calculation of the electrostatic interaction energy for five hydrogen-bonded dimers at standard and nonstandard hydrogen-bonded geometries and at nonequilibrium geometries; (2) calculation of the electrostatic molecular properties (potential and electric field) for eight small molecular systems (methanol, ammonia, water, formamide, dichloromethane, acetone, dimethyl sulfoxide, and acetonitrile) and for the 20 amino acids. Our results show that the methodology performs well not only for small molecules but also for relatively larger molecular systems. The analysis of the distinct parameter sets associated with different optimization strategies show that (i) a specific parameter set is more suitable and more general for electrostatic interaction energy calculations, with an average absolute error of 0.46 kcal/mol at hydrogen-bond geometries; (ii) a second parameter set is more suitable for electrostatic potential and electric field calculations at and outside the van der Waals (vdW) envelope, with an average error decrease >72% at the vdW surface. A more general amino acid damping parameter set was constructed from the

  3. Multipolar, time-dynamical model for the loss compensation and lasing of a spherical plasmonic nanoparticle spaser immersed in an active gain medium

    PubMed Central

    Veltri, Alessandro; Chipouline, Arkadi; Aradian, Ashod

    2016-01-01

    The plasmonic response of a metal nanoparticle in the presence of surrounding gain elements is studied, using a space and time-dependent model, which integrates a quantum formalism to describe the gain and a classical treatment for the metal. Our model fully takes into account the influence of the system geometry (nanosphere) and offers for the first time, the possibility to describe the temporal evolution of the fields and the coupling among the multipolar modes of the particle. We calculate the lasing threshold value for all multipoles of the spaser, and demonstrate that the dipolar one is lowest. The onset of the lasing instability, in the linear regime, is then studied both with and without external field forcing. We also study the behaviour of the system below the lasing threshold, with the external field, demonstrating the existence of an amplification regime where the nanoparticle’s plasmon is strongly enhanced as the threshold is approached. Finally, a qualitative discussion is provided on later, non-linear stages of the dynamics and the approach to the steady-state of the spaser; in particular, it is shown that, for the considered geometry, the spasing is necessarily multi-modal and multipolar modes are always activated. PMID:27625072

  4. Multipolar, time-dynamical model for the loss compensation and lasing of a spherical plasmonic nanoparticle spaser immersed in an active gain medium

    NASA Astrophysics Data System (ADS)

    Veltri, Alessandro; Chipouline, Arkadi; Aradian, Ashod

    2016-09-01

    The plasmonic response of a metal nanoparticle in the presence of surrounding gain elements is studied, using a space and time-dependent model, which integrates a quantum formalism to describe the gain and a classical treatment for the metal. Our model fully takes into account the influence of the system geometry (nanosphere) and offers for the first time, the possibility to describe the temporal evolution of the fields and the coupling among the multipolar modes of the particle. We calculate the lasing threshold value for all multipoles of the spaser, and demonstrate that the dipolar one is lowest. The onset of the lasing instability, in the linear regime, is then studied both with and without external field forcing. We also study the behaviour of the system below the lasing threshold, with the external field, demonstrating the existence of an amplification regime where the nanoparticle’s plasmon is strongly enhanced as the threshold is approached. Finally, a qualitative discussion is provided on later, non-linear stages of the dynamics and the approach to the steady-state of the spaser; in particular, it is shown that, for the considered geometry, the spasing is necessarily multi-modal and multipolar modes are always activated.

  5. C3G/Rapgef1 Is Required in Multipolar Neurons for the Transition to a Bipolar Morphology during Cortical Development.

    PubMed

    Shah, Bhavin; Lutter, Daniela; Bochenek, Magdalena L; Kato, Katsuhiro; Tsytsyura, Yaroslav; Glyvuk, Natalia; Sakakibara, Akira; Klingauf, Jürgen; Adams, Ralf H; Püschel, Andreas W

    2016-01-01

    The establishment of a polarized morphology is essential for the development and function of neurons. During the development of the mammalian neocortex, neurons arise in the ventricular zone (VZ) from radial glia cells (RGCs) and leave the VZ to generate the cortical plate (CP). During their migration, newborn neurons first assume a multipolar morphology in the subventricular zone (SVZ) and lower intermediate zone (IZ). Subsequently, they undergo a multi-to-bipolar (MTB) transition to become bipolar in the upper IZ by developing a leading process and a trailing axon. The small GTPases Rap1A and Rap1B act as master regulators of neural cell polarity in the developing mouse neocortex. They are required for maintaining the polarity of RGCs and directing the MTB transition of multipolar neurons. Here we show that the Rap1 guanine nucleotide exchange factor (GEF) C3G (encoded by the Rapgef1 gene) is a crucial regulator of the MTB transition in vivo by conditionally inactivating the Rapgef1 gene in the developing mouse cortex at different time points during neuronal development. Inactivation of C3G results in defects in neuronal migration, axon formation and cortical lamination. Live cell imaging shows that C3G is required in cortical neurons for both the specification of an axon and the initiation of radial migration by forming a leading process.

  6. A theoretical analysis of HLA-DRbeta1*0301-CLIP complex using the first three multipolar moments of the electrostatic field.

    PubMed

    Balbín, Alejandro; Cárdenas, Constanza; Villaveces, José Luis; Patarroyo, Manuel E

    2006-09-01

    Interactions between the HLA-DRbeta1*0301 molecule and several occupying peptides obtained from computational substitutions made to the CLIP peptide are studied. The exploration was carried out using a vector composed of the first three terms of the multipolar expansion of the electrostatic field, namely, charge (q), dipole (d) and quadrupole (C). Comparisons between pocket-peptide interactions established that the binding pockets for this HLA molecule are ordered in terms of their importance for binding peptides, as follows: P1 > P4 > P6 > P7 > P9. A set of electrostatically distinct amino acids that determine interaction stability and specificity were identified for each pocket. The beta74R residue was especially identified as being the key amino acid mediating the occupying peptide binding for pocket 4; this residue has been recently associated with Graves' disease.

  7. Multi-Frequency and Multi-Polarization Study on SAR-Based Coastal AReas Characterization: The Case of the Yellow River Delta

    NASA Astrophysics Data System (ADS)

    Buono, Andrea; Nunziata, Ferdinando; Migliaccio, Maurizio; Li, Xiaofeng; Shen, Dongliang; Ding, Xianwen

    2016-08-01

    The Yellow River is the most sediment-filled river and the sixth-longest one in the world. It is of paramount importance for safe navigation, local economy and environment due to the presence of floods, farms, aquacultures and pollution. Further, the Yellow River delta is characterized by several physical phenomena due to both natural and anthropogenic processes: sedimentation, erosion, floods, pollution, etc.In this study, actual partially-overlapped L-/C-band fully- polarimetric (FP) synthetic aperture radar (SAR) data are used to investigate the scattering properties of the Yellow River delta, whose very complex area is characterized by different environments as recorded by ground truth data acquired during a ship-based in-situ campaign. Preliminary results witness that multi-polarization and multi-frequency SAR measurements allow inferring more physical information in such a complex environment that can be used as starting point for developing ad hoc classification algorithms.

  8. Transferred multipolar atom model for 10β,17β-dihydroxy-17α-methylestr-4-en-3-one dihydrate obtained from the biotransformation of methyloestrenolone.

    PubMed

    Faroque, Muhammad Umer; Yousuf, Sammer; Zafar, Salman; Choudhary, M Iqbal; Ahmed, Maqsood

    2016-05-01

    Biotransformation is the structural modification of compounds using enzymes as the catalysts and it plays a key role in the synthesis of pharmaceutically important compounds. 10β,17β-Dihydroxy-17α-methylestr-4-en-3-one dihydrate, C19H28O3·2H2O, was obtained from the fungal biotransformation of methyloestrenolone. The structure was refined using the classical independent atom model (IAM) and a transferred multipolar atom model using the ELMAM2 database. The results from the two refinements have been compared. The ELMAM2 refinement has been found to be superior in terms of the refinement statistics. It has been shown that certain electron-density-derived properties can be calculated on the basis of the transferred parameters for crystals which diffract to ordinary resolution.

  9. Was the Devonian geomagnetic field dipolar or multipolar? Palaeointensity studies of Devonian igneous rocks from the Minusa Basin (Siberia) and the Kola Peninsula dykes, Russia

    NASA Astrophysics Data System (ADS)

    Shcherbakova, V. V.; Biggin, A. J.; Veselovskiy, R. V.; Shatsillo, A. V.; Hawkins, L.; Shcherbakov, V. P.; Zhidkov, G. V.

    2017-02-01

    Defining variations in the behaviour of the geomagnetic field through geological time is critical to understanding the dynamics of Earth's core and its response to mantle convection and planetary evolution. Furthermore, the question of whether the axial dipole dominance of the recent palaeomagnetic field persists through the whole of Earth's history is fundamental to determining the reliability of palaeogeographic reconstructions and the efficacy of the magnetosphere in shielding Earth from solar wind radiation. Previous palaeomagnetic directional studies have suggested that the palaeofield had a complex configuration in the Devonian period (419-359 Ma). Here we present new palaeointensity determinations from rocks aged between 408 and 375 Ma from the Minusa Basin (southern Siberia), and the Kola Peninsula to investigate the strength of the field during this enigmatic period. Palaeointensity experiments were performed using the thermal Thellier, microwave Thellier, and Wilson methods on 165 specimens from 25 sites. Six out of eight successful sites from the Minusa Basin and all four successful sites from the Kola Peninsula produced extremely low palaeointensities (< 10 μT). These findings challenge the uniformitarian view of the palaeomagnetic field: field intensities of nearly an order of magnitude lower than Neogene values (except during relatively rare geomagnetic excursions and reversals) together with the widespread appearance of strange directions found in the Devonian suggest that the Earth's field during this time may have had a dominantly multipolar geometry. A persistent, low intensity multipolar magnetic field and associated diminished magnetosphere would increase the impact of solar particles on the Earth's magnetosphere, ionosphere and atmosphere with potential major implications for Earth's climate and biosphere.

  10. Cellular and Molecular Characterization of Multipolar Map5-Expressing Cells: A Subset of Newly Generated, Stage-Specific Parenchymal Cells in the Mammalian Central Nervous System

    PubMed Central

    Crociara, Paola; Parolisi, Roberta; Conte, Daniele; Fumagalli, Marta; Bonfanti, Luca

    2013-01-01

    Although extremely interesting in adult neuro-glio-genesis and promising as an endogenous source for repair, parenchymal progenitors remain largely obscure in their identity and physiology, due to a scarce availability of stage-specific markers. What appears difficult is the distinction between real cell populations and various differentiation stages of the same population. Here we focused on a subset of multipolar, polydendrocyte-like cells (mMap5 cells) expressing the microtubule associated protein 5 (Map5), which is known to be present in most neurons. We characterized the morphology, phenotype, regional distribution, proliferative dynamics, and stage-specific marker expression of these cells in the rabbit and mouse CNS, also assessing their existence in other mammalian species. mMap5 cells were never found to co-express the Ng2 antigen. They appear to be a population of glial cells sharing features but also differences with Ng2+progenitor cells. We show that mMap5 cells are newly generated, postmitotic parenchymal elements of the oligodendroglial lineage, thus being a stage-specific population of polydendrocytes. Finally, we report that the number of mMap5 cells, although reduced within the brain of adult/old animals, can increase in neurodegenerative and traumatic conditions. PMID:23667595

  11. Charge-density analysis using multipolar atom and spherical charge models: 2-methyl-1,3-cyclopentanedione, a compound displaying a resonance-assisted hydrogen bond.

    PubMed

    Nassour, Ayoub; Kubicki, Maciej; Wright, Jonathan; Borowiak, Teresa; Dutkiewicz, Grzegorz; Lecomte, Claude; Jelsch, Christian

    2014-04-01

    The experimental charge-density distribution in 2-methyl-1,3-cyclopentanedione in the crystal state was analyzed by synchrotron X-ray diffraction data collection at 0.33 Å resolution. The molecule in the crystal is in the enol form. The experimental electron density was refined using the Hansen-Coppens multipolar model and an alternative modeling, based on spherical atoms and additional charges on the covalent bonds and electron lone-pair sites. The crystallographic refinements, charge-density distributions, molecular electrostatic potentials, dipole moments and intermolecular interaction energies obtained from the different charge-density models were compared. The experimental results are also compared with the theoretical charge densities using theoretical structure factors obtained from periodic quantum calculations at the B3LYP/6-31G** level. A strong intermolecular O-H···O hydrogen bond connects molecules along the [001] direction. The deformation density maps show the resonance within the O=C-C=C-OH fragment and merged lone pair lobes on the hydroxyl O atom. This resonance is further confirmed by the analysis of charges and topology of the electron density.

  12. Cellular and molecular characterization of multipolar Map5-expressing cells: a subset of newly generated, stage-specific parenchymal cells in the mammalian central nervous system.

    PubMed

    Crociara, Paola; Parolisi, Roberta; Conte, Daniele; Fumagalli, Marta; Bonfanti, Luca

    2013-01-01

    Although extremely interesting in adult neuro-glio-genesis and promising as an endogenous source for repair, parenchymal progenitors remain largely obscure in their identity and physiology, due to a scarce availability of stage-specific markers. What appears difficult is the distinction between real cell populations and various differentiation stages of the same population. Here we focused on a subset of multipolar, polydendrocyte-like cells (mMap5 cells) expressing the microtubule associated protein 5 (Map5), which is known to be present in most neurons. We characterized the morphology, phenotype, regional distribution, proliferative dynamics, and stage-specific marker expression of these cells in the rabbit and mouse CNS, also assessing their existence in other mammalian species. mMap5 cells were never found to co-express the Ng2 antigen. They appear to be a population of glial cells sharing features but also differences with Ng2+progenitor cells. We show that mMap5 cells are newly generated, postmitotic parenchymal elements of the oligodendroglial lineage, thus being a stage-specific population of polydendrocytes. Finally, we report that the number of mMap5 cells, although reduced within the brain of adult/old animals, can increase in neurodegenerative and traumatic conditions.

  13. Building on the EGIPPS performance assessment: the multipolar framework as a heuristic to tackle the complexity of performance of public service oriented health care organisations

    PubMed Central

    2014-01-01

    Background Performance of health care systems is a key concern of policy makers and health service managers all over the world. It is also a major challenge, given its multidimensional nature that easily leads to conceptual and methodological confusion. This is reflected by a scarcity of models that comprehensively analyse health system performance. Discussion In health, one of the most comprehensive performance frameworks was developed by the team of Leggat and Sicotte. Their framework integrates 4 key organisational functions (goal attainment, production, adaptation to the environment, and values and culture) and the tensions between these functions. We modified this framework to better fit the assessment of the performance of health organisations in the public service domain and propose an analytical strategy that takes it into the social complexity of health organisations. The resulting multipolar performance framework (MPF) is a meta-framework that facilitates the analysis of the relations and interactions between the multiple actors that influence the performance of health organisations. Summary Using the MPF in a dynamic reiterative mode not only helps managers to identify the bottlenecks that hamper performance, but also the unintended effects and feedback loops that emerge. Similarly, it helps policymakers and programme managers at central level to better anticipate the potential results and side effects of and required conditions for health policies and programmes and to steer their implementation accordingly. PMID:24742181

  14. Scalable improvement of SPME multipolar electrostatics in anisotropic polarizable molecular mechanics using a general short-range penetration correction up to quadrupoles

    PubMed Central

    Narth, Christophe; Lagardère, Louis; Polack, Étienne; Gresh, Nohad; Wang, Qiantao; Bell, David R.; Rackers, Joshua A.; Ponder, Jay W.; Ren, Pengyu Y.; Piquemal, Jean-Philip

    2015-01-01

    We propose a general coupling of the Smooth Particle Mesh Ewald (spme) approach for distributed multipoles to a short-range charge penetration correction modifying the charge-charge, charge-dipole and charge-quadrupole energies. Such an approach significantly improves electrostatics when compared to ab initio values and has been calibrated on Symmetry-Adapted Perturbation Theory (sapt) reference data. Various neutral molecular dimers have been tested as results on charged systems (metal cation complexes) are provided. Transferability of the correction is adressed in the context of the implementation of the amoeba and sibfa polarizable force fields in the Tinker-hp software. As the choices of the multipolar distribution are discussed, conclusions are drawn for the future penetration-corrected polarizable force fields highlighting the mandatory need of non-spurious procedures for the obtention of well balanced and physically meaningful distributed moments. Finally scalability and parallelism of the short-range corrected spme approach are addressed, demonstrating that the damping function is computationally affordable and accurate for molecular dynamics simulations of complexe bio- or bioinorganic systems in periodic boundary conditions. PMID:26814845

  15. On the use of L-band multipolarization airborne SAR for surveys of crops, vineyards, and orchards in a California irrigated agricultural region

    NASA Technical Reports Server (NTRS)

    Paris, J. F.

    1985-01-01

    The airborne L-band synthetic aperture radar (SAR) collected multipolarization calibrated image data over an irrigated agricultural test site near Fresno, CA, on March 6, 1984. The conclusions of the study are as follows: (1) the effects of incidence angle on the measured backscattering coefficients could be removed by using a correction factor equal to the secant of the angle raised to the 1.4 power, (2) for this scene and time of year, the various polarization channels were highly correlated such that the use of more than one polarization added little to the ability of the radar to discriminate vegetation type or condition; the exception was barley which separated from vineyards only when a combination of like and cross polarization data were used (polarization was very useful for corn identification in fall crops), (3) an excellent separation between herbaceous vegetation (alfalfa, barley, and oats) or bare fields and trees in orchards existed in brightness was well correlated to alfalfa height or biomass, especially for the HH polarization combination, (5) vineyards exhibited a narrow range of brightnesses with no systematic effects of type or number of stakes nor of number of wires in the trellises nor of the size of the vines, (6) within the orchard classes, areal biomass characterized by basal area differences caused radar image brightness differences for small to medium trees but not for medium to large trees.

  16. The terminal basal mitosis of chicken retinal Lim1 horizontal cells is not sensitive to cisplatin-induced cell cycle arrest.

    PubMed

    Shirazi Fard, Shahrzad; Thyselius, Malin; All-Ericsson, Charlotta; Hallböök, Finn

    2014-01-01

    For proper development, cells need to coordinate proliferation and cell cycle-exit. This is mediated by a cascade of proteins making sure that each phase of the cell cycle is controlled before the initiation of the next. Retinal progenitor cells divide during the process of interkinetic nuclear migration, where they undergo S-phase on the basal side, followed by mitoses on the apical side of the neuroepithelium. The final cell cycle of chicken retinal horizontal cells (HCs) is an exception to this general cell cycle behavior. Lim1 expressing (+) horizontal progenitor cells (HPCs) have a heterogenic final cell cycle, with some cells undergoing a terminal mitosis on the basal side of the retina. The results in this study show that this terminal basal mitosis of Lim1+ HPCs is not dependent on Chk1/2 for its regulation compared to retinal cells undergoing interkinetic nuclear migration. Neither activating nor blocking Chk1 had an effect on the basal mitosis of Lim1+ HPCs. Furthermore, the Lim1+ HPCs were not sensitive to cisplatin-induced DNA damage and were able to continue into mitosis in the presence of γ-H2AX without activation of caspase-3. However, Nutlin3a-induced expression of p21 did reduce the mitoses, suggesting the presence of a functional p53/p21 response in HPCs. In contrast, the apical mitoses were blocked upon activation of either Chk1/2 or p21, indicating the importance of these proteins during the process of interkinetic nuclear migration. Inhibiting Cdk1 blocked M-phase transition both for apical and basal mitoses. This confirmed that the cyclin B1-Cdk1 complex was active and functional during the basal mitosis of Lim1+ HPCs. The regulation of the final cell cycle of Lim1+ HPCs is of particular interest since it has been shown that the HCs are able to sustain persistent DNA damage, remain in the cell cycle for an extended period of time and, consequently, survive for months.

  17. Harnessing Fluorine–Sulfur Contacts and Multipolar Interactions for the Design of p53 Mutant Y220C Rescue Drugs

    PubMed Central

    2016-01-01

    Many oncogenic mutants of the tumor suppressor p53 are conformationally unstable, including the frequently occurring Y220C mutant. We have previously developed several small-molecule stabilizers of this mutant. One of these molecules, PhiKan083, 1-(9-ethyl-9H-carbazole-3-yl)-N-methylmethanamine, binds to a mutation-induced surface crevice with a KD = 150 μM, thereby increasing the melting temperature of the protein and slowing its rate of aggregation. Incorporation of fluorine atoms into small molecule ligands can substantially improve binding affinity to their protein targets. We have, therefore, harnessed fluorine–protein interactions to improve the affinity of this ligand. Step-wise introduction of fluorines at the carbazole ethyl anchor, which is deeply buried within the binding site in the Y220C–PhiKan083 complex, led to a 5-fold increase in affinity for a 2,2,2-trifluoroethyl anchor (ligand efficiency of 0.3 kcal mol–1 atom–1). High-resolution crystal structures of the Y220C–ligand complexes combined with quantum chemical calculations revealed favorable interactions of the fluorines with protein backbone carbonyl groups (Leu145 and Trp146) and the sulfur of Cys220 at the mutation site. Affinity gains were, however, only achieved upon trifluorination, despite favorable interactions of the mono- and difluorinated anchors with the binding pocket, indicating a trade-off between energetically favorable protein–fluorine interactions and increased desolvation penalties. Taken together, the optimized carbazole scaffold provides a promising starting point for the development of high-affinity ligands to reactivate the tumor suppressor function of the p53 mutant Y220C in cancer cells. PMID:27267810

  18. Harnessing Fluorine-Sulfur Contacts and Multipolar Interactions for the Design of p53 Mutant Y220C Rescue Drugs.

    PubMed

    Bauer, Matthias R; Jones, Rhiannon N; Baud, Matthias G J; Wilcken, Rainer; Boeckler, Frank M; Fersht, Alan R; Joerger, Andreas C; Spencer, John

    2016-08-19

    Many oncogenic mutants of the tumor suppressor p53 are conformationally unstable, including the frequently occurring Y220C mutant. We have previously developed several small-molecule stabilizers of this mutant. One of these molecules, PhiKan083, 1-(9-ethyl-9H-carbazole-3-yl)-N-methylmethanamine, binds to a mutation-induced surface crevice with a KD = 150 μM, thereby increasing the melting temperature of the protein and slowing its rate of aggregation. Incorporation of fluorine atoms into small molecule ligands can substantially improve binding affinity to their protein targets. We have, therefore, harnessed fluorine-protein interactions to improve the affinity of this ligand. Step-wise introduction of fluorines at the carbazole ethyl anchor, which is deeply buried within the binding site in the Y220C-PhiKan083 complex, led to a 5-fold increase in affinity for a 2,2,2-trifluoroethyl anchor (ligand efficiency of 0.3 kcal mol(-1) atom(-1)). High-resolution crystal structures of the Y220C-ligand complexes combined with quantum chemical calculations revealed favorable interactions of the fluorines with protein backbone carbonyl groups (Leu145 and Trp146) and the sulfur of Cys220 at the mutation site. Affinity gains were, however, only achieved upon trifluorination, despite favorable interactions of the mono- and difluorinated anchors with the binding pocket, indicating a trade-off between energetically favorable protein-fluorine interactions and increased desolvation penalties. Taken together, the optimized carbazole scaffold provides a promising starting point for the development of high-affinity ligands to reactivate the tumor suppressor function of the p53 mutant Y220C in cancer cells.

  19. Properties of native P2X receptors in large multipolar neurons dissociated from rat hypothalamic arcuate nucleus.

    PubMed

    Wakamori, Minoru; Sorimachi, Masaru

    2004-04-16

    ATP, the ligand of P2X receptors, is a candidate of neurotransmitter or co-transmitter in the peripheral and the central nervous systems. Anatomical studies have revealed the wide distribution of P2X receptors in the brain. So far, P2X-mediated small synaptic responses have been recorded in some brain regions. To determine the physiological significance of postsynaptic ATP receptors in the brain, we have investigated the P2X responses in rat dissociated hypothalamic arcuate neurons by using the patch-clamp technique. ATP evoked inward currents in a concentration-dependent manner (EC(50)=42 microM) at a holding potential of -70 mV. The current-voltage relationship showed a marked inward rectification starting around -10 mV. Although neither 300 microM alphabeta-methylene-ATP nor 300 microM betagamma-methylene-ATP induced any currents, 100 microM ATPgammaS and 100 microM 2-methylthio-ATP evoked inward currents of which amplitude was about 60% of the control currents evoked by 100 microM ATP. PPADS, one of P2 receptor antagonists, inhibited the ATP-evoked currents in a time- and a concentration-dependent manners (IC(50)=19 microM at 2 min). Permeant Ca(2+) inhibited the ATP-evoked currents in the range of millimolars (IC(50)=7 mM); however, Cd(2+) (1-300 microM), a broad cation channel blocker, facilitated the currents with slow off-response. Zn(2+) in the range of 1-100 microM facilitated the currents whereas Zn(2+) at the concentrations over 100 microM inhibited the currents. These observations suggest that functional P2X receptors are expressed in the hypothalamic arcuate nucleus. The most likely subunit combinations of the P2X receptors are P2X(2)-homomultimer and P2X(2)/P2X(6)-heteromultimer.

  20. Stokes and anti-Stokes luminescence in Tm(3+)/Yb(3+)-doped Lu3Ga5O12 nano-garnets: a study of multipolar interactions and energy transfer dynamics.

    PubMed

    Rathaiah, Mamilla; Haritha, Pamuluri; Lozano-Gorrín, Antonio Diego; Babu, Palamandala; Jayasankar, Chalicheemalapalli Kulala; Rodríguez-Mendoza, Ulises Ruyman; Lavín, Victor; Venkatramu, Vemula

    2016-06-07

    Nanocrystalline Lu3Ga5O12 garnets doped with Tm(3+)/Yb(3+) ions have been synthesized by a low cost and environmentally benign sol-gel technique and characterized for their structural, Stokes and anti-Stokes luminescence properties. The diffuse reflectance spectra of doped Lu3Ga5O12 nano-garnets have been measured to derive the partial energy level structure of Tm(3+) and Yb(3+) ions and possible energy transfer channels between them. Upon laser excitation at 473 nm, weak red and intense near-infrared Stokes emissions have been observed in the nano-garnets. The decay curves of (3)H4 and (1)G4 levels of Tm(3+) ions and the (2)F5/2 level of Yb(3+) ions have been measured upon resonant laser excitation and are found to be non-exponential in nature due to multipolar interactions. In order to know the kind of multipolar interaction among optically active ions, the decay curves are analyzed through the generalized Yokota-Tanimoto model. Moreover, under 970 nm laser excitation, intense blue anti-Stokes emission is observed by the naked eye in Tm(3+)-Yb(3+) co-doped Lu3Ga5O12 nano-garnets. The results show that as-synthesized nano-garnets may be useful in the field of phosphors and photonics.

  1. A Unipolar or Multipolar World?

    DTIC Science & Technology

    1992-03-11

    doom for the American economy. Economist Paul Krugman in The Age of Diminished Expectations believes that sour economic performance today is broadly... Paul Krugman , The Aqe of Diminished ExDectations (Washington, DC: The Washington Post Co., 1990), 5. 44Huntington, 84. 4 5Nye, ’Still in the Game, 45

  2. Polarizable multipolar electrostatics for cholesterol

    NASA Astrophysics Data System (ADS)

    Fletcher, Timothy L.; Popelier, Paul L. A.

    2016-08-01

    FFLUX is a novel force field under development for biomolecular modelling, and is based on topological atoms and the machine learning method kriging. Successful kriging models have been obtained for realistic electrostatics of amino acids, small peptides, and some carbohydrates but here, for the first time, we construct kriging models for a sizeable ligand of great importance, which is cholesterol. Cholesterol's mean total (internal) electrostatic energy prediction error amounts to 3.9 kJ mol-1, which pleasingly falls below the threshold of 1 kcal mol-1 often cited for accurate biomolecular modelling. We present a detailed analysis of the error distributions.

  3. Prediction of vapor-liquid equilibrium and PVTx properties of geological fluid system with SAFT-LJ EOS including multi-polar contribution. Part I: Application to H 2O-CO 2 system

    NASA Astrophysics Data System (ADS)

    Sun, Rui; Dubessy, Jean

    2010-04-01

    Molecular based equations of state (EOS) are attractive because they can take into account the energetic contribution of the main types of molecular interactions. This study models vapor-liquid equilibrium (VLE) and PVTx properties of the H 2O-CO 2 binary system using a Lennard-Jones (LJ) referenced SAFT (Statistical Associating Fluid Theory) EOS. The improved SAFT-LJ EOS is defined in terms of the residual molar Helmholtz energy, which is a sum of four terms representing the contributions from LJ segment-segment interactions, chain-forming among the LJ segments, short-range associations and long-range multi-polar interactions. CO 2 is modeled as a linear chain molecule with a constant quadrupole moment, and H 2O is modeled as a spherical molecule with four association sites and a dipole moment. The multi-polar contribution to Helmholtz energy, including the dipole-dipole, dipole-quadrupole, and quadrupole-quadrupole contribution for H 2O-CO 2 system, is calculated using the theory of Gubbins and Twu (1978). Six parameters for pure H 2O and four parameters for pure CO 2 are needed in our model. The Van der Waals one-fluid mixing rule is used to calculate the Lennard-Jones energy parameter and volume parameter for the mixture. Two or three binary parameters are needed for CO 2-H 2O mixtures, which are evaluated from phase equilibrium data of the binary system. Comparison with the experimental data shows that our model represents the PVT properties of CO 2 better than other SAFT EOS without a quadrupole contribution. For the CO 2-H 2O system, our model agrees well with the vapor-liquid equilibrium data from 323-623 K. The average relative deviation for CO 2 solubility (expressed in mole fraction) in water is within 6%. Our model can also predict the PVTx properties of CO 2-H 2O mixtures up to 1073 K and 3000 bar. The good performance of this model indicates that: (1) taking account of the multi-polar contribution explicitly improves the agreement of calculated

  4. Gadolinium chloride pretreatment ameliorates acute cadmium-induced hepatotoxicity.

    PubMed

    Kyriakou, Loukas G; Tzirogiannis, Konstantinos N; Demonakou, Maria D; Kourentzi, Kalliopi T; Mykoniatis, Michael G; Panoutsopoulos, Georgios I

    2013-08-01

    Cadmium is a known industrial and environmental pollutant. It causes hepatotoxicity upon acute administration. Features of cadmium-induced acute hepatoxicity encompass necrosis, apoptosis, peliosis and inflammatory infiltration. Gadolinium chloride (GdCl3) may prevent cadmium-induced hepatotoxicity by suppressing Kupffer cells. The effect of GdCl3 pretreatment on a model of acute cadmium-induced liver injury was investigated. Male Wistar rats 4-5 months old were injected intraperitoneally with normal saline followed by cadmium chloride (CdCl2; 6.5 mg/kg) or GdCl3 (10 mg/kg) followed by CdCl2 (6.5 mg/kg; groups I and II, respectively). Rats of both the groups were killed at 9, 12, 16, 24, 48 and 60 h after cadmium intoxication. Liver sections were analyzed for necrosis, apoptosis, peliosis and mitoses. Liver regeneration was also evaluated by tritiated thymidine incorporation into hepatic DNA. Serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were also determined. Hepatic necrosis, hepatocyte and nonparenchymal cell apoptosis and macroscopic and microscopic types of peliosis hepatis were minimized by gadolinium pretreatment. Serum levels of AST and ALT were also greatly diminished in rats of group II. Tritiated thymidine incorporation into hepatic DNA was increased in gadolinium pretreatment rats. Kupffer cell activation was minimal in both the groups of rats. Gadolinium pretreatment attenuates acute cadmium-induced liver injury in young Wistar rats, with mechanisms other than Kupffer cell elimination.

  5. Calculation of vapor-liquid equilibrium and PVTx properties of geological fluid system with SAFT-LJ EOS including multi-polar contribution. Part III. Extension to water-light hydrocarbons systems

    NASA Astrophysics Data System (ADS)

    Sun, Rui; Lai, Shaocong; Dubessy, Jean

    2014-01-01

    The SAFT-LJ EOS improved by Sun and Dubessy (2010, 2012) is extended to water-light hydrocarbon systems. Light hydrocarbons (including CH4, C2H6, C3H8 and nC4H10) are modeled as chain molecules without multi-polar moments. The contributions of the shape of molecules and main intermolecular interactions existing in water-light hydrocarbon systems (including repulsive and attractive forces between Lennard-Jones segments, the hydrogen-bonding force and the multi-polar interaction between water molecules) to the residual Helmholtz energy were accounted for by this EOS. The adjustable parameters for the interactions of H2O-CH4, H2O-C2H6, H2O-C3H8, and H2O-nC4H10 pairs were evaluated from mutual solubility data of binary water-hydrocarbon systems at vapor-liquid equilibria. Comparison with the experimental data shows this SAFT-LJ EOS can represent well vapor-liquid (and liquid-liquid) equilibria of binary water-light hydrocarbon systems over a wide P-T range. The accuracy of this EOS for mutual solubilities of methane, ethane, propane and water is within the experimental uncertainty generally. Moreover, the model is able to accurately predict the vapor-liquid equilibria and PVTx properties of multi-component systems composed of water, light hydrocarbon as well as CO2. As we know, this EOS is the first one allowing quantitative calculation of the mutual solubilities of water and light hydrocarbons over a wide P-T range among SAFT-type EOSs. This work indicates that the molecular-based EOS combined with conventional mixing rule can well describe the thermodynamic behavior of highly non-ideal systems such as water-light hydrocarbons mixtures except in the critical region for which long range density fluctuations cannot be taken into account by this analytical model.

  6. Harmonic filters for 3D multichannel data: rotation invariant detection of mitoses in colorectal cancer.

    PubMed

    Schlachter, Matthias; Reisert, Marco; Herz, Corinna; Schlürmann, Fabienne; Lassmann, Silke; Werner, Martin; Burkhardt, Hans; Ronneberger, Olaf

    2010-08-01

    In this paper, we present a novel approach for a trainable rotation invariant detection of complex structures in 3D microscopic multichannel data using a nonlinear filter approach. The basic idea of our approach is to compute local features in a window around each 3D position and map these features by means of a nonlinear mapping onto new local harmonic descriptors of the local window. These local harmonic descriptors are then combined in a linear way to form the output of the filter. The optimal combination of the computed local harmonic descriptors is determined in previous training step, and allows the filter to be adapted to an arbitrary structure depending on the problem at hand. Our approach is not limited to scalar-valued images and can also be used for vector-valued (multichannel) images such as gradient vector flow fields. We present realizations of a scalar-valued and a vector-valued multichannel filter. Our proposed algorithm was quantitatively evaluated on colorectal cancer cell lines (cells grown under controlled conditions), on which we successfully detected complex 3D mitotic structures. For a qualitative evaluation we tested our algorithms on human 3D tissue samples of colorectal cancer. We compare our results with a steerable filter approach as well as a morphology-based approach.

  7. High-resolution neutron and X-ray diffraction room-temperature studies of an H-FABP-oleic acid complex: study of the internal water cluster and ligand binding by a transferred multipolar electron-density distribution.

    PubMed

    Howard, E I; Guillot, B; Blakeley, M P; Haertlein, M; Moulin, M; Mitschler, A; Cousido-Siah, A; Fadel, F; Valsecchi, W M; Tomizaki, Takashi; Petrova, T; Claudot, J; Podjarny, A

    2016-03-01

    Crystal diffraction data of heart fatty acid binding protein (H-FABP) in complex with oleic acid were measured at room temperature with high-resolution X-ray and neutron protein crystallography (0.98 and 1.90 Å resolution, respectively). These data provided very detailed information about the cluster of water molecules and the bound oleic acid in the H-FABP large internal cavity. The jointly refined X-ray/neutron structure of H-FABP was complemented by a transferred multipolar electron-density distribution using the parameters of the ELMAMII library. The resulting electron density allowed a precise determination of the electrostatic potential in the fatty acid (FA) binding pocket. Bader's quantum theory of atoms in molecules was then used to study interactions involving the internal water molecules, the FA and the protein. This approach showed H⋯H contacts of the FA with highly conserved hydrophobic residues known to play a role in the stabilization of long-chain FAs in the binding cavity. The determination of water hydrogen (deuterium) positions allowed the analysis of the orientation and electrostatic properties of the water molecules in the very ordered cluster. As a result, a significant alignment of the permanent dipoles of the water molecules with the protein electrostatic field was observed. This can be related to the dielectric properties of hydration layers around proteins, where the shielding of electrostatic interactions depends directly on the rotational degrees of freedom of the water molecules in the interface.

  8. High-resolution neutron and X-ray diffraction room-temperature studies of an H-FABP–oleic acid complex: study of the internal water cluster and ligand binding by a transferred multipolar electron-density distribution

    PubMed Central

    Howard, E. I.; Guillot, B.; Blakeley, M. P.; Haertlein, M.; Moulin, M.; Mitschler, A.; Cousido-Siah, A.; Fadel, F.; Valsecchi, W. M.; Tomizaki, Takashi; Petrova, T.; Claudot, J.; Podjarny, A.

    2016-01-01

    Crystal diffraction data of heart fatty acid binding protein (H-FABP) in complex with oleic acid were measured at room temperature with high-resolution X-ray and neutron protein crystallography (0.98 and 1.90 Å resolution, respectively). These data provided very detailed information about the cluster of water molecules and the bound oleic acid in the H-FABP large internal cavity. The jointly refined X-ray/neutron structure of H-FABP was complemented by a transferred multipolar electron-density distribution using the parameters of the ELMAMII library. The resulting electron density allowed a precise determination of the electrostatic potential in the fatty acid (FA) binding pocket. Bader’s quantum theory of atoms in molecules was then used to study interactions involving the internal water molecules, the FA and the protein. This approach showed H⋯H contacts of the FA with highly conserved hydrophobic residues known to play a role in the stabilization of long-chain FAs in the binding cavity. The determination of water hydrogen (deuterium) positions allowed the analysis of the orientation and electrostatic properties of the water molecules in the very ordered cluster. As a result, a significant alignment of the permanent dipoles of the water molecules with the protein electrostatic field was observed. This can be related to the dielectric properties of hydration layers around proteins, where the shielding of electrostatic interactions depends directly on the rotational degrees of freedom of the water molecules in the interface. PMID:27006775

  9. Computer Simulation of the far Infrared Collision Induced Absorption Spectra of Gaseous CO2

    NASA Technical Reports Server (NTRS)

    Gruszka, Marcin; Borysow, Aleksandra

    1998-01-01

    Far infrared collision induced absorption spectra of gaseous CO2 were computed using molecular dynamics simulations. The quadrupole and hexadecapole multipolar induction, through the trace, and the anisotropy of the molecular polarizability were found to be insufficient to represent properly the dipole induction mechanism. For a detailed analysis of the induction process the spectra obtained were decomposed into components resulting from different terms of the induced dipole. Based on this decomposition, all additional overlap contribution for each term was proposed. When spectra were recomputed including such overlap, good agreement between experiment and simulation was achieved over the temperature range at which measurements exist (233-400 K). The use of an anisotropic intermolecular potential was found to be of critical importance for obtaining the right shape of the far wings of the spectra.

  10. Information Content Analysis for the Multi-Viewing, Multi-Channel, Multi-Polarization Imaging (3MI) Instrument : Toward Retrieval of Vertically Resolved Cloud Properties from Passive Only Measurements.

    NASA Astrophysics Data System (ADS)

    Riedi, J.; Merlin, G.; Labonnote, L.; Cornet, C.; Ferlay, N.; Desmons, M.; Dubuisson, P.; Parol, F.; Davis, A. B.; Marbach, T.

    2014-12-01

    The EUMETSAT Polar System- Second Generation (EPS-SG) is currently under development to take over the current EUMETSAT Polar System at the 2020 horizon. As part of it, the Multi-Viewing Multi-Channel Multi-Polarization Imaging mission (3MI) will be dedicated to the operational monitoring of aerosols but will also provide unique observations for characterization of cloud properties building on the legacy of POLDER and particularly of its 3rd mission (PARASOL) within the A-Train. Through the synergy of POLDER3/PARASOL and MODIS/AQUA several studies have demonstrated the great interest of combining multispectral, multiangle and polarization measurements in the visible, near and shortwave infrared to better constrain retrieval of clouds microphysical and macrophysical properties. Remote-sensing of cloud thermodynamic phase (Riedi et al, 2010), liquid (Bréon and Doutriaux-Boucher, 2005) or ice clouds microphysics (Zhang et al, 2009; Cole et al, 2012), cloud radiative (Zeng et al, 2012) or macrophysical properties (Ferlay et al, 2010; Desmons et al, 2013) can unarguably benefit from the additional information content brought by polarization and multiangle measurements. At the same time, retrieval algorithms are gaining further complexity and skills. Thanks to availability of computational resources, practical implementation of optimal estimation or related optimization techniques (Delanoe & Hogan, 2008; Dubovik et al, 2013) have appeared that allow simultaneous and consistent retrieval of larger sets of parameters from constantly growing observations vectors. Therefore 3MI observations will not only allow to improve accuracy of future cloud products but also opens perspectives for the development of new retrieval algorithms. A major challenge for cloud remote-sensing from passive measurements is to obtain information on clouds properties vertical distribution and structure. Through results of a comprehensive information content analysis we will illustrate our current

  11. Multipolar interference for directed light emission.

    PubMed

    Hancu, Ion M; Curto, Alberto G; Castro-López, Marta; Kuttge, Martin; van Hulst, Niek F

    2014-01-08

    By directing light, optical antennas can enhance light-matter interaction and improve the efficiency of nanophotonic devices. Here we exploit the interference among the electric dipole, quadrupole, and magnetic dipole moments of a split-ring resonator to experimentally realize a compact directional optical antenna. This single-element antenna design robustly directs emission even when covered with nanometric emitters at random positions, outperforming previously demonstrated nanoantennas with a bandwidth of 200 nm and a directivity of 10.1 dB from a subwavelength structure. The advantages of this approach bring directional optical antennas closer to practical applications.

  12. Somatic tetraploidy in specific chick retinal ganglion cells induced by nerve growth factor

    PubMed Central

    Morillo, Sandra M.; Escoll, Pedro; de la Hera, Antonio; Frade, José M.

    2009-01-01

    A subset of neurons in the normal vertebrate nervous system contains double the normal amount of DNA in their nuclei. These neurons are all thought to derive from aberrant mitoses in neuronal precursor cells. Here we show that endogenous NGF induces DNA replication in a subpopulation of differentiating chick retinal ganglion cells that express both the neurotrophin receptor p75 and the E2F1 transcription factor, but that lack the retinoblastoma protein. Many of these neurons avoid G2/M transition and remain alive in the retina as tetraploid cells with large cell somas and extensive dendritic trees, and most of them express β2 nicotinic acetylcholine receptor subunits, a specific marker of retinal ganglion cells innervating lamina F in the stratum-griseum-et-fibrosum-superficiale of the tectal cortex. Tetraploid neurons were also observed in the adult mouse retina. Thus, a developmental program leading to somatic tetraploidy in specific retinal neurons exists in vertebrates. This program might occur in other vertebrate neurons during normal or pathological situations. PMID:20018664

  13. Assembly of Reconfigurable Colloidal Structures by Multidirectional Field-Induced Interactions.

    PubMed

    Bharti, Bhuvnesh; Velev, Orlin D

    2015-07-28

    Field-directed colloidal assembly has shown remarkable recent progress in increasing the complexity, degree of control, and multiscale organization of the structures. This has largely been achieved by using particles of complex shapes and polarizabilites (Janus, patchy, shaped, and faceted). We review the fundamentals of the interactions leading to the directed assembly of such structures, the ways to simulate the dynamics of the process, and the effect of particle size, shape, and properties on the type of structure obtained. We discuss how directional polarization interactions induced by external electric and magnetic fields can be used to assemble complex particles or particle mixtures into lattices of tailored structure. Examples of such systems include isotropic and anisotropic shaped particles with surface patches, which form networks and crystals of unusual symmetry by dipolar, quadrupolar, and multipolar interactions in external fields. The emerging trends in making reconfigurable and dynamic structures are discussed.

  14. Mitotic Stress Is an Integral Part of the Oncogene-Induced Senescence Program that Promotes Multinucleation and Cell Cycle Arrest

    PubMed Central

    Dikovskaya, Dina; Cole, John J.; Mason, Susan M.; Nixon, Colin; Karim, Saadia A.; McGarry, Lynn; Clark, William; Hewitt, Rachael N.; Sammons, Morgan A.; Zhu, Jiajun; Athineos, Dimitris; Leach, Joshua D.G.; Marchesi, Francesco; van Tuyn, John; Tait, Stephen W.; Brock, Claire; Morton, Jennifer P.; Wu, Hong; Berger, Shelley L.; Blyth, Karen; Adams, Peter D.

    2015-01-01

    Summary Oncogene-induced senescence (OIS) is a tumor suppression mechanism that blocks cell proliferation in response to oncogenic signaling. OIS is frequently accompanied by multinucleation; however, the origin of this is unknown. Here, we show that multinucleate OIS cells originate mostly from failed mitosis. Prior to senescence, mutant H-RasV12 activation in primary human fibroblasts compromised mitosis, concordant with abnormal expression of mitotic genes functionally linked to the observed mitotic spindle and chromatin defects. Simultaneously, H-RasV12 activation enhanced survival of cells with damaged mitoses, culminating in extended mitotic arrest and aberrant exit from mitosis via mitotic slippage. ERK-dependent transcriptional upregulation of Mcl1 was, at least in part, responsible for enhanced survival and slippage of cells with mitotic defects. Importantly, mitotic slippage and oncogene signaling cooperatively induced senescence and key senescence effectors p21 and p16. In summary, activated Ras coordinately triggers mitotic disruption and enhanced cell survival to promote formation of multinucleate senescent cells. PMID:26299965

  15. Mitotic Stress Is an Integral Part of the Oncogene-Induced Senescence Program that Promotes Multinucleation and Cell Cycle Arrest.

    PubMed

    Dikovskaya, Dina; Cole, John J; Mason, Susan M; Nixon, Colin; Karim, Saadia A; McGarry, Lynn; Clark, William; Hewitt, Rachael N; Sammons, Morgan A; Zhu, Jiajun; Athineos, Dimitris; Leach, Joshua D G; Marchesi, Francesco; van Tuyn, John; Tait, Stephen W; Brock, Claire; Morton, Jennifer P; Wu, Hong; Berger, Shelley L; Blyth, Karen; Adams, Peter D

    2015-09-01

    Oncogene-induced senescence (OIS) is a tumor suppression mechanism that blocks cell proliferation in response to oncogenic signaling. OIS is frequently accompanied by multinucleation; however, the origin of this is unknown. Here, we show that multinucleate OIS cells originate mostly from failed mitosis. Prior to senescence, mutant H-RasV12 activation in primary human fibroblasts compromised mitosis, concordant with abnormal expression of mitotic genes functionally linked to the observed mitotic spindle and chromatin defects. Simultaneously, H-RasV12 activation enhanced survival of cells with damaged mitoses, culminating in extended mitotic arrest and aberrant exit from mitosis via mitotic slippage. ERK-dependent transcriptional upregulation of Mcl1 was, at least in part, responsible for enhanced survival and slippage of cells with mitotic defects. Importantly, mitotic slippage and oncogene signaling cooperatively induced senescence and key senescence effectors p21 and p16. In summary, activated Ras coordinately triggers mitotic disruption and enhanced cell survival to promote formation of multinucleate senescent cells.

  16. Ruta Graveolens Extract Induces DNA Damage Pathways and Blocks Akt Activation to Inhibit Cancer Cell Proliferation and Survival

    PubMed Central

    FADLALLA, KHALDA; WATSON, ANGELA; YEHUALAESHET, TESHOME; TURNER, TIMOTHY; SAMUEL, TEMESGEN

    2011-01-01

    Background Ruta graveolens is a medicinal herb that has been used for centuries against various ailments. This study examined the anticancer properties of the herb using cancer cell lines. Materials and Methods Methanolic extract of R. graveolens was tested on colon, breast and prostate cancer cells. Viability, cell cycle profiles, clonogenicity and capase activation were measured. Induction and subcellular localizations of p53, 53BP1 and γ-H2AX proteins were examined. Results the extract dose-dependently decreased the viability and the clonogenicity of treated cells and induced G2/M arrest, aberrant mitoses, and caspase-3 activation. It also induced the p53 pathway and focal concentration of the DNA damage response proteins 53BP1 and γ-H2AX. Moreover, the levels of phospho-Akt and cyclin B1 were reduced by treatment, whereas only cyclin B1 was reduced in normal dermal fibroblasts. Conclusion R. graveolens extract contains bioactive compounds which, independently of known photoactivatable mechanisms, potently inhibit cancer cell proliferation and survival through multiple targets. PMID:21273604

  17. Intraperitoneal mesotheliomas induced in mice by a polycyclic aromatic hydrocarbon

    SciTech Connect

    Rice, J.M.; Anderson, L.M. ); Kovatch, R.M. )

    1989-01-01

    Female mice of 6 strains (C3H/HeN, BALB/c, C57BL/6N, DBA/2, NIH Swiss, and AKR/N) were given the polycyclic aromatic hydrocarbon carcinogen 3-methylcholanthrene (MC) intragastrically in olive oil at a dose of 20 mg/kg, weekly for 12 wk. Half were pretreated 24 h before each MC administration with intraperitoneal {beta}-naphthoflavone ({beta}-NF, 150 mg/kg in olive oil), a noncarinogenic inducer of certain cytochrome P-450 isozymes. Remaining mice were given olive oil prior to MC in the same fashion, or {beta}-NF in olive oil or olive oil alone without subsequent exposure to MC. All mice were killed when moribund or 13 mo after the start of treatment. Most of the mice, irrespective of treatment, exhibited signs of peritoneal injury, including inflammation, necrosis, granuloma formation, and mineralization. Mice of some of the strains also presented peritoneal mesotheliomas, in addition to a variety of other tumors. {beta}-NF pretreatment reduced the frequency of mesotheliomas: there was only one definite mesothelioma in any of the {beta}-NF-MC groups, in a C3H/He mouse. Most of the measotheliomas were mixed fibro-mesothelial type, sometimes with papillary epithelial excrescences. They typically grew in a botryoid pattern within the peritoneal cavity, coating the abdominal organs and sometimes actively invading these organs and the diaphragm. Some lesions exhibited pleomorphism, prominent giant cells, and frequent mitoses. In addition, several lesions consisting of severe mesothelial hyperplasia associated with tissue necrosis and inflammation were considered as possible early stages of mesothelioma development. It was postulated that peritoneal injury imposed by repeated intraperitoneal injection of oil acted as an enhancing factor for mesothelioma induction by MC.

  18. Microcystin-LR and Cylindrospermopsin Induced Alterations in Chromatin Organization of Plant Cells

    PubMed Central

    Máthé, Csaba; M-Hamvas, Márta; Vasas, Gábor

    2013-01-01

    Cyanobacteria produce metabolites with diverse bioactivities, structures and pharmacological properties. The effects of microcystins (MCYs), a family of peptide type protein-phosphatase inhibitors and cylindrospermopsin (CYN), an alkaloid type of protein synthesis blocker will be discussed in this review. We are focusing mainly on cyanotoxin-induced changes of chromatin organization and their possible cellular mechanisms. The particularities of plant cells explain the importance of such studies. Preprophase bands (PPBs) are premitotic cytoskeletal structures important in the determination of plant cell division plane. Phragmoplasts are cytoskeletal structures involved in plant cytokinesis. Both cyanotoxins induce the formation of multipolar spindles and disrupted phragmoplasts, leading to abnormal sister chromatid segregation during mitosis. Thus, MCY and CYN are probably inducing alterations of chromosome number. MCY induces programmed cell death: chromatin condensation, nucleus fragmentation, necrosis, alterations of nuclease and protease enzyme activities and patterns. The above effects may be related to elevated reactive oxygen species (ROS) and/or disfunctioning of microtubule associated proteins. Specific effects: MCY-LR induces histone H3 hyperphosphorylation leading to incomplete chromatid segregation and the formation of micronuclei. CYN induces the formation of split or double PPB directly related to protein synthesis inhibition. Cyanotoxins are powerful tools in the study of plant cell organization. PMID:24084787

  19. Induced Abortion

    MedlinePlus

    ... Education & Events Advocacy For Patients About ACOG Induced Abortion Home For Patients Search FAQs Induced Abortion Page ... Induced Abortion FAQ043, May 2015 PDF Format Induced Abortion Special Procedures What is an induced abortion? What ...

  20. PRR11 regulates late-S to G2/M phase progression and induces premature chromatin condensation (PCC)

    SciTech Connect

    Zhang, Chundong; Zhang, Ying; Li, Yi; Zhu, Huifang; Wang, Yitao; Cai, Wei; Zhu, Jiang; Ozaki, Toshinori; Bu, Youquan

    2015-03-13

    Recently, we have demonstrated that proline-rich protein 11 (PRR11) is a novel tumor-related gene product likely implicated in the regulation of cell cycle progression as well as lung cancer development. However, its precise role in cell cycle progression remains unclear. In the present study, we have further investigated the expression pattern and functional implication of PRR11 during cell cycle in detail in human lung carcinoma-derived H1299 cells. According to our immunofluorescence study, PRR11 was expressed largely in cytoplasm, the amount of PRR11 started to increase in the late S phase, and was retained until just before mitotic telophase. Consistent with those observations, siRNA-mediated knockdown of PRR11 caused a significant cell cycle arrest in the late S phase. Intriguingly, the treatment with dNTPs further augmented PRR11 silencing-mediated S phase arrest. Moreover, knockdown of PRR11 also resulted in a remarkable retardation of G2/M progression, and PRR11-knockdown cells subsequently underwent G2 phase cell cycle arrest accompanied by obvious mitotic defects such as multipolar spindles and multiple nuclei. In addition, forced expression of PRR11 promoted the premature Chromatin condensation (PCC), and then proliferation of PRR11-expressing cells was massively attenuated and induced apoptosis. Taken together, our current observations strongly suggest that PRR11, which is strictly regulated during cell cycle progression, plays a pivotal role in the regulation of accurate cell cycle progression through the late S phase to mitosis. - Highlights: • PRR11 started to increase in the late S phase and was retained until just before mitotic telophase. • PRR11-knockdown caused a significant cell cycle arrest in the late S phase and G2 phase. • The treatment with dNTPs further augmented PRR11 silencing-mediated S phase arrest. • PRR11-knockdown led to multipolar spindles and multiple nuclei. • Forced expression of PRR11 promoted the PCC and inhibited

  1. Trivalent dimethylarsenic compound induces histone H3 phosphorylation and abnormal localization of Aurora B kinase in HepG2 cells

    SciTech Connect

    Suzuki, Toshihide; Miyazaki, Koichi; Kita, Kayoko; Ochi, Takafumi

    2009-12-15

    Trivalent dimethylarsinous acid [DMA(III)] has been shown to induce mitotic abnormalities, such as centrosome abnormality, multipolar spindles, multipolar division, and aneuploidy, in several cell lines. In order to elucidate the mechanisms underlying these mitotic abnormalities, we investigated DMA(III)-mediated changes in histone H3 phosphorylation and localization of Aurora B kinase, which is a key molecule in cell mitosis. DMA(III) caused the phosphorylation of histone H3 (ser10) and was distributed predominantly in mitotic cells, especially in prometaphase cells. By contrast, most of the phospho-histone H3 was found to be localized in interphase cells after treatment with inorganic arsenite [iAs(III)], suggesting the involvement of a different pathway in phosphorylation. DMA(III) activated Aurora B kinase and slightly activated ERK MAP kinase. Phosphorylation of histone H3 by DMA(III) was effectively reduced by ZM447439 (Aurora kinase inhibitor) and slightly reduced by U0126 (MEK inhibitor). By contrast, iAs(III)-dependent histone H3 phosphorylation was markedly reduced by U0126. Aurora B kinase is generally localized in the midbody during telophase and plays an important role in cytokinesis. However, in some cells treated with DMA(III), Aurora B was not localized in the midbody of telophase cells. These findings suggested that DMA(III) induced a spindle abnormality, thereby activating the spindle assembly checkpoint (SAC) through the Aurora B kinase pathway. In addition, cytokinesis was not completed because of the abnormal localization of Aurora B kinase by DMA(III), thereby resulting in the generation of multinucleated cells. These results provide insight into the mechanism of arsenic tumorigenesis.

  2. Protective Effects of Quercetin against Dimethoate-Induced Cytotoxicity and Genotoxicity in Allium sativum Test.

    PubMed

    Ahmad, Waseem; Shaikh, Sibhghatulla; Nazam, Nazia; Lone, Mohammad Iqbal

    2014-01-01

    The present investigation was directed to study the possible protective activity of quercetin-a natural antioxidant against dimethoate-induced cyto- and genotoxicity in meristematic cells of Allium sativum. So far there is no report on the biological properties of quercetin in plant test systems. Chromosome breaks, multipolar anaphase, stick chromosome, and mitotic activity were undertaken in the current study as markers of cyto- and genotoxicity. Untreated control, quercetin controls (@ 5, 10 and 20 μg/mL for 3 h), and dimethoate exposed groups (@ 100 and 200 μg/mL for 3 h) were maintained. For protection against cytogenotoxicity, the root tip cells treated with dimethoate at 100 and 200 μg/mL for 3 h and quercetin treatment at 5, 10, and 20 μg/mL for 16 h, prior to dimethoate treatment, were undertaken. Quercetin was found to be neither cytotoxic nor genotoxic in Allium sativum control at these doses. A significant increase (P < 0.05) in chromosomal aberrations was noted in dimethoate treated Allium. Pretreatment of Allium sativum with quercetin significantly (P < 0.05) reduced dimethoate-induced genotoxicity and cytotoxicity in meristematic cells, and these effects were dose dependent. In conclusion, quercetin has a protective role in the abatement of dimethoate-induced cyto- and genotoxicity in the meristematic cells of Allium sativum that resides, at least in part, on its antioxidant effects.

  3. Protective Effects of Quercetin against Dimethoate-Induced Cytotoxicity and Genotoxicity in Allium sativum Test

    PubMed Central

    Ahmad, Waseem; Shaikh, Sibhghatulla; Nazam, Nazia; Lone, Mohammad Iqbal

    2014-01-01

    The present investigation was directed to study the possible protective activity of quercetin—a natural antioxidant against dimethoate-induced cyto- and genotoxicity in meristematic cells of Allium sativum. So far there is no report on the biological properties of quercetin in plant test systems. Chromosome breaks, multipolar anaphase, stick chromosome, and mitotic activity were undertaken in the current study as markers of cyto- and genotoxicity. Untreated control, quercetin controls (@ 5, 10 and 20 μg/mL for 3 h), and dimethoate exposed groups (@ 100 and 200 μg/mL for 3 h) were maintained. For protection against cytogenotoxicity, the root tip cells treated with dimethoate at 100 and 200 μg/mL for 3 h and quercetin treatment at 5, 10, and 20 μg/mL for 16 h, prior to dimethoate treatment, were undertaken. Quercetin was found to be neither cytotoxic nor genotoxic in Allium sativum control at these doses. A significant increase (P < 0.05) in chromosomal aberrations was noted in dimethoate treated Allium. Pretreatment of Allium sativum with quercetin significantly (P < 0.05) reduced dimethoate-induced genotoxicity and cytotoxicity in meristematic cells, and these effects were dose dependent. In conclusion, quercetin has a protective role in the abatement of dimethoate-induced cyto- and genotoxicity in the meristematic cells of Allium sativum that resides, at least in part, on its antioxidant effects. PMID:27379342

  4. Zika virus infection induces mitosis abnormalities and apoptotic cell death of human neural progenitor cells

    PubMed Central

    Souza, Bruno S. F.; Sampaio, Gabriela L. A.; Pereira, Ciro S.; Campos, Gubio S.; Sardi, Silvia I.; Freitas, Luiz A. R.; Figueira, Claudio P.; Paredes, Bruno D.; Nonaka, Carolina K. V.; Azevedo, Carine M.; Rocha, Vinicius P. C.; Bandeira, Antonio C.; Mendez-Otero, Rosalia; dos Santos, Ricardo Ribeiro; Soares, Milena B. P.

    2016-01-01

    Zika virus (ZIKV) infection has been associated with severe complications both in the developing and adult nervous system. To investigate the deleterious effects of ZIKV infection, we used human neural progenitor cells (NPC), derived from induced pluripotent stem cells (iPSC). We found that NPC are highly susceptible to ZIKV and the infection results in cell death. ZIKV infection led to a marked reduction in cell proliferation, ultrastructural alterations and induction of autophagy. Induction of apoptosis of Sox2+ cells was demonstrated by activation of caspases 3/7, 8 and 9, and by ultrastructural and flow cytometry analyses. ZIKV-induced death of Sox2+ cells was prevented by incubation with the pan-caspase inhibitor, Z-VAD-FMK. By confocal microscopy analysis we found an increased number of cells with supernumerary centrosomes. Live imaging showed a significant increase in mitosis abnormalities, including multipolar spindle, chromosome laggards, micronuclei and death of progeny after cell division. FISH analysis for chromosomes 12 and 17 showed increased frequency of aneuploidy, such as monosomy, trisomy and polyploidy. Our study reinforces the link between ZIKV and abnormalities in the developing human brain, including microcephaly. PMID:28008958

  5. Induction of Excess Centrosomes in Neural Progenitor Cells during the Development of Radiation-Induced Microcephaly

    PubMed Central

    Shimada, Mikio; Matsuzaki, Fumio; Kato, Akihiro; Kobayashi, Junya; Matsumoto, Tomohiro; Komatsu, Kenshi

    2016-01-01

    The embryonic brain is one of the tissues most vulnerable to ionizing radiation. In this study, we showed that ionizing radiation induces apoptosis in the neural progenitors of the mouse cerebral cortex, and that the surviving progenitor cells subsequently develop a considerable amount of supernumerary centrosomes. When mouse embryos at Day 13.5 were exposed to γ-rays, brains sizes were reduced markedly in a dose-dependent manner, and these size reductions persisted until birth. Immunostaining with caspase-3 antibodies showed that apoptosis occurred in 35% and 40% of neural progenitor cells at 4 h after exposure to 1 and 2 Gy, respectively, and this was accompanied by a disruption of the apical layer in which mitotic spindles were positioned in unirradiated mice. At 24 h after 1 Gy irradiation, the apoptotic cells were completely eliminated and proliferation was restored to a level similar to that of unirradiated cells, but numerous spindles were localized outside the apical layer. Similarly, abnormal cytokinesis, which included multipolar division and centrosome clustering, was observed in 19% and 24% of the surviving neural progenitor cells at 48 h after irradiation with 1 and 2 Gy, respectively. Because these cytokinesis aberrations derived from excess centrosomes result in growth delay and mitotic catastrophe-mediated cell elimination, our findings suggest that, in addition to apoptosis at an early stage of radiation exposure, radiation-induced centrosome overduplication could contribute to the depletion of neural progenitors and thereby lead to microcephaly. PMID:27367050

  6. Over-expression of Plk4 induces centrosome amplification, loss of primary cilia and associated tissue hyperplasia in the mouse

    PubMed Central

    Coelho, Paula A.; Bury, Leah; Shahbazi, Marta N.; Liakath-Ali, Kifayathullah; Tate, Peri H.; Wormald, Sam; Hindley, Christopher J.; Huch, Meritxell; Archer, Joy; Skarnes, William C.; Zernicka-Goetz, Magdalena; Glover, David M.

    2015-01-01

    To address the long-known relationship between supernumerary centrosomes and cancer, we have generated a transgenic mouse that permits inducible expression of the master regulator of centriole duplication, Polo-like-kinase-4 (Plk4). Over-expression of Plk4 from this transgene advances the onset of tumour formation that occurs in the absence of the tumour suppressor p53. Plk4 over-expression also leads to hyperproliferation of cells in the pancreas and skin that is enhanced in a p53 null background. Pancreatic islets become enlarged following Plk4 over-expression as a result of equal expansion of α- and β-cells, which exhibit centrosome amplification. Mice overexpressing Plk4 develop grey hair due to a loss of differentiated melanocytes and bald patches of skin associated with a thickening of the epidermis. This reflects an increase in proliferating cells expressing keratin 5 in the basal epidermal layer and the expansion of these cells into suprabasal layers. Such cells also express keratin 6, a marker for hyperplasia. This is paralleled by a decreased expression of later differentiation markers, involucrin, filaggrin and loricrin. Proliferating cells showed an increase in centrosome number and a loss of primary cilia, events that were mirrored in primary cultures of keratinocytes established from these animals. We discuss how repeated duplication of centrioles appears to prevent the formation of basal bodies leading to loss of primary cilia, disruption of signalling and thereby aberrant differentiation of cells within the epidermis. The absence of p53 permits cells with increased centrosomes to continue dividing, thus setting up a neoplastic state of error prone mitoses, a prerequisite for cancer development. PMID:26701933

  7. Centrosomal amplification and aneuploidy induced by the antiretroviral drug AZT in hamster and human cells

    PubMed Central

    Borojerdi, Jennifer P.; Ming, Jessica; Cooch, Catherine; Ward, Yvona; Semino-Mora, Cristina; Yu, Mia; Braun, Hannan M.; Taylor, Barbara J.; Poirier, Miriam C.; Olivero, Ofelia A.

    2009-01-01

    The centrosome directs chromosomal migration by a complex process of tubulin-chromatin binding. In this contribution centrosomal abnormalities, including centrosomal amplification, were explored in Chinese Hamster Ovary (CHO) and Normal Human Mammary Epithelial (NHMEC) cells exposed to the antiretroviral drug zidovudine (3’-azido-3’-deoxythymidine, AZT). Centrosomal amplification/fragmentation was observed in both cell types and kinetochore positive micronuclei were found in AZT-exposed CHO cells in correlation with dose. Normal human mammary epithelial cell (NMHEC), strain M99005, previously identified as a strain that incorporates high levels of AZT into DNA (High incorporator, HI), showed greater centrosomal amplification when compared with a second strain, NHMEC M98040, which did not incorporate AZT into DNA (Low incorporator, LI). Additionally, an abnormal tubulin distribution was observed in AZT-exposed HI cells bearing multiple centrosomes. Immunofluorescent staining of human cells with Aurora A, a kinase involved in the maturation of the centrosome, confirmed the induction of centrosomal amplification and revealed multipolar mitotic figures. Flow cytometric studies revealed that cells bearing abnormal numbers of centrosomes and abnormal tubulin distribution had similar S-phase percentages suggesting that cells bearing unbalanced chromosomal segregation could divide. Therefore, AZT induces genomic instability and clastogenicity as well as alterations in proteins involved in centrosomal activation, all of which may contribute to the carcinogenic properties of this compound. PMID:19427513

  8. Chromosomal and Nuclear Alterations in Root Tip Cells of Allium Cepa L. Induced by Alprazolam

    PubMed Central

    Nefic, Hilada; Musanovic, Jasmin; Metovic, Azra; Kurteshi, Kemajl

    2013-01-01

    ABSTRACT Introduction: Alprazolam is a triazolobenzodiazepine used in panic disorders and other anxiety states. Target organ of Alprazolam is CNS, causing depression of respiration and consciousness. Aim: This study aimed to estimate the genotoxic potential of Alprazolam using Allium cepa test. Methods: Allium cepa is one of the most suitable plants for detecting different types of xenobiotics. The test enables the assessment of different genetic endpoints making possible damage to the DNA of humans to be predicted. Results: Alprazolam induced chromosomal (anaphase bridges, breaks, lagging and stickiness, abnormal spiralisation, multipolarity and polyploidy) and cytological aberrations, especially nuclear alterations (nuclear buds, fragmented nucleus and apoptotic bodies, cells without nucleus, binucleated and micronucleated cells), morphological alterations in shape and size of cells, spindle disturbance and polar deviation in root tip meristem cells of Allium cepa at all tested concentrations. Alprazolam also caused significant inhibition of mitotic index in these cells. Conclusion: These changes in cells are indicators of genotoxic potential of Alprazolam suggesting a need for further in vitro studies on animal and human lymphocytes as well as in vivo studies. PMID:25568504

  9. Hyperthermia induces cytoskeletal alterations and mitotic catastrophe in p53-deficient H1299 lung cancer cells.

    PubMed

    Pawlik, Andrzej; Nowak, Jakub Marcin; Grzanka, Dariusz; Gackowska, Lidia; Michalkiewicz, Jacek; Grzanka, Alina

    2013-01-01

    Hyperthermia is used in cancer therapy, however much remains to be discovered regarding its mechanisms of action at the cellular level. In this study, the effects of hyperthermia on cell death, survival, morphology and the cytoskeleton were investigated in a non-small cell lung cancer cell line, H1299. Despite the fact that this cell line is widely used in research, it has not yet been tested for heat shock sensitivity. Cells were given a 30-min heat shock at 43.5°C and 45°C and left to recover at 37°C for 24 and 48 h. 24 h after heat shock treatment, we monitored changes in the organization of the cytoskeleton using immunofluorescence microscopy. The number of actin stress fibers was significantly reduced, microtubules formed a looser meshwork, a portion of the cells possessed multipolar mitotic spindles, whereas vimentin filaments collapsed into perinuclear complexes. 48 h following heat stress, most of the cells showed recovery of the cytoskeleton, however we observed a considerable number of giant cells that were multinucleated or contained one enlarged nucleus. The data obtained by MTT assay showed a dose-dependent decrease of cell viability, while flow cytometric analysis revealed an increase in the number of cells with externalized phosphatidylserine. The results suggest that one of the modes of heat-induced cell death in H1299 cells is mitotic catastrophe, which probably ends in apoptosis.

  10. Arsenite-induced mitotic death involves stress response and is independent of tubulin polymerization

    SciTech Connect

    Taylor, B. Frazier; McNeely, Samuel C.; Miller, Heather L.; States, J. Christopher

    2008-07-15

    Arsenite, a known mitotic disruptor, causes cell cycle arrest and cell death at anaphase. The mechanism causing mitotic arrest is highly disputed. We compared arsenite to the spindle poisons nocodazole and paclitaxel. Immunofluorescence analysis of {alpha}-tubulin in interphase cells demonstrated that, while nocodazole and paclitaxel disrupt microtubule polymerization through destabilization and hyperpolymerization, respectively, microtubules in arsenite-treated cells remain comparable to untreated cells even at supra-therapeutic concentrations. Immunofluorescence analysis of {alpha}-tubulin in mitotic cells showed spindle formation in arsenite- and paclitaxel-treated cells but not in nocodazole-treated cells. Spindle formation in arsenite-treated cells appeared irregular and multi-polar. {gamma}-tubulin staining showed that cells treated with nocodazole and therapeutic concentrations of paclitaxel contained two centrosomes. In contrast, most arsenite-treated mitotic cells contained more than two centrosomes, similar to centrosome abnormalities induced by heat shock. Of the three drugs tested, only arsenite treatment increased expression of the inducible isoform of heat shock protein 70 (HSP70i). HSP70 and HSP90 proteins are intimately involved in centrosome regulation and mitotic spindle formation. HSP90 inhibitor 17-DMAG sensitized cells to arsenite treatment and increased arsenite-induced centrosome abnormalities. Combined treatment of 17-DMAG and arsenite resulted in a supra-additive effect on viability, mitotic arrest, and centrosome abnormalities. Thus, arsenite-induced abnormal centrosome amplification and subsequent mitotic arrest is independent of effects on tubulin polymerization and may be due to specific stresses that are protected against by HSP90 and HSP70.

  11. Spectral Moments of Collision-Induced Absorption of CO2 Pairs: The Role of the Intermolecular Potential

    NASA Technical Reports Server (NTRS)

    Gruszka, Marcin; Borysow, Aleksandra

    1994-01-01

    In this paper we examine the role of the anisotropy of the intermolecular potential in the rototranslational collision-induced absorption of the CO2 pairs. Using newly developed formulas that include the effects of anisotropy of the potential to all orders, we calculate the two lowest spectral moments gamma(prime), and alpha(prime), for four different classes of C02 pair potentials and compare the results with the experimental values. We assumed only multipolar induction in the process of forming the induced dipole, with the second-order contributions included. Using a site-site LJ and a site-site semi-ab initio intermolecular potentials we were able to reproduce the experimental values of gamma(prime), and alpha(prime) moments over entire temperature range from 230 to 330 K. Also, the role of an electrostatic interaction between two C02 molecules and its impact on the spectral moments is thoroughly investigated. An isotropic core with a point quadrupole centered at each molecule is shown to be an inadequate representation of the C02-CO2 potential. Additionally, we show the results obtained with the first- and second-order perturbation theory to be more than twice too small.

  12. Shape-Induced Deformation, Capillary Bridging, and Self-Assembly of Cuboids at the Fluid-Fluid Interface.

    PubMed

    Anjali, Thriveni G; Basavaraj, Madivala G

    2017-01-24

    The controlled assembly of anisotropic particles through shape-induced interface deformations is shown to be a potential route for the fabrication of novel functional materials. In this article, the shape-induced interface deformation, capillary bridging, and directed self-assembly of cuboidal-shaped hematite particles at fluid-fluid interfaces are reported. The multipolar nature of the interface distortions is directly visualized using high-resolution scanning electron microscopy and 3D optical surface profiling. The nature of the interface deformations around cuboidal particles vary from monopolar to octupolar types depending on their orientation and position with respect to the interface. The deformations are of either hexapolar or octupolar type in the face-up orientation, quadrupolar or monopolar type in the edge-up orientation, and monopolar type in the vertex-up orientation. The particles adsorbed at the interface interact through the interface deformations, forming capillary bridges that lead to isolated assemblies of two or more particles. The arrangement of particles in any assembly is such that the condition for capillary attraction is satisfied, that is, in accordance with predictions based on the nature of interface deformations. At sufficient particle concentrations, these isolated structures interact to form a percolating network of cuboids. Furthermore, the difference in the nature of the assembly structures formed at the air-water interface and in the bulk water phase indicates that the interfacial assembly of these particles is controlled by the capillary interactions.

  13. Multipolarization radar images for geologic mapping and vegetation discrimination

    NASA Technical Reports Server (NTRS)

    Evans, D. L.; Farr, T. G.; Ford, J. P.; Thompson, T. W.; Werner, C. L.

    1986-01-01

    NASA has developed an airborne SAR that simultaneously yields image data in four linear polarizations in L-band with 10-m resolution over a swath of about 10 km. Signal data are recorded both optically and digitally and annotated in each of the channels to facilitate completely automated digital correlation. Comparison of the relative intensities of the different polarizations furnishes discriminatory mapping information. Local intensity variations in like-polarization images result from topographic effects, while strong cross polarization responses denote the effects of vegetation cover and, in some cases, possible scattering from the subsurface. In each of the areas studied, multiple polarization data led to the discrimination and mapping of unique surface unit features.

  14. Challenges in the Multipolar Space-Power Environment

    DTIC Science & Technology

    2007-07-01

    Aeronautic and Space Company (EADS) Astrium , and Alcatel Space. The AlphaBus communication satellite will bring advanced technology at lower costs to...Space and Astrium .” 7. ESA, “Safer Train Circulation.” 8. “ESI Overview,” European Space Incubator. 9. About the European Space Incubators Network...European Space Agency [ESA]. “Alcatel Space and Astrium Forge Agreement for AlphaBus,” 20 June 2003. http://www.esa .int/esaTE/SEMADPVO4HD_index_0.html

  15. Investigation of vegetation with multifrequency and multipolarization SAR systems

    NASA Astrophysics Data System (ADS)

    Winter, Rudolf; Roth, Achim; Bayer, Thomas

    1990-05-01

    Investigations of vegetation is conducted by synergism of different types of digital image data and models. As a standard application, satellite images are digitally coregistered with existant topographical data and stored in the Geographic Information Systems (GIS). The usefulness of multiparametric SAR (Synthetic Aperture Radar) data for vegetation mapping is discussed. The multifrequency aspects requires precise geocoding. Different application fields with recent results are discussed: forest investigations with SIR (Spaceborne Imaging Radar)-B data in the southern Rhine valley ; extraction of landuse categories in landscape units using two geocoded Seasat-SAR scenes in the area of Bonn; relief effects on image gray values in geocoded Seasat-SAR images; the concept of a remote sensing data base for ecological applications.

  16. 2-(3-Methoxyphenyl)-5-methyl-1,8-naphthyridin-4(1H)-one (HKL-1) induces G2/M arrest and mitotic catastrophe in human leukemia HL-60 cells

    SciTech Connect

    Hsu, Mei-Hua; Liu, Chin-Yu; Lin, Chiao-Min; Chen, Yen-Jung; Chen, Chun-Jen; Lin, Yu-Fu; Huang, Li-Jiau; Lee, Kuo-Hsiung; Kuo, Sheng-Chu

    2012-03-01

    2-(3-Methoxyphenyl)-5-methyl-1,8-naphthyridin-4(1H)-one (HKL-1), a 2-phenyl-1,8-naphthyridin-4-one (2-PN) derivative, was synthesized and evaluated as an effective antimitotic agent in our laboratory. However, the molecular mechanisms are uncertain. In this study, HKL-1 was demonstrated to induce multipolar spindles, sustain mitotic arrest and generate multinucleated cells, all of which indicate mitotic catastrophe, in human leukemia HL-60 cells. Western blotting showed that HKL-1 induces mitotic catastrophe in HL-60 cells through regulating mitotic phase-specific kinases (down-regulating CDK1, cyclin B1, CENP-E, and aurora B) and regulating the expression of Bcl-2 family proteins (down-regulating Bcl-2 and up-regulating Bax and Bak), followed by caspase-9/-3 cleavage. These findings suggest that HKL-1 appears to exert its cytotoxicity toward HL-60 cells in culture by inducing mitotic catastrophe. Highlights: ► HKL-1 is a potential antimitotic agent against HL-60 cells. ► HKL-1 induces spindle disruption and sustained resulted in mitotic catastrophe. ► CENP-E and aurora B protein expressions significantly reduced. ► Bcl-2 family protein expressions altered and caspase-9/-3 activation. ► HKL-1 is an attractive candidate for possible use as a novel antimitotic agent.

  17. Inducing labor

    MedlinePlus

    ... inducing labor is to "break the bag of waters" or rupture the membranes. Your health care provider will do a pelvic exam and will guide a small plastic probe with a hook on the end through your cervix to create a hole in the membrane. This does not hurt you ...

  18. Genotoxicity of multi-walled carbon nanotubes at occupationally relevant doses.

    PubMed

    Siegrist, Katelyn J; Reynolds, Steven H; Kashon, Michael L; Lowry, David T; Dong, Chenbo; Hubbs, Ann F; Young, Shih-Houng; Salisbury, Jeffrey L; Porter, Dale W; Benkovic, Stanley A; McCawley, Michael; Keane, Michael J; Mastovich, John T; Bunker, Kristin L; Cena, Lorenzo G; Sparrow, Mark C; Sturgeon, Jacqueline L; Dinu, Cerasela Zoica; Sargent, Linda M

    2014-01-30

    Carbon nanotubes are commercially-important products of nanotechnology; however, their low density and small size makes carbon nanotube respiratory exposures likely during their production or processing. We have previously shown mitotic spindle aberrations in cultured primary and immortalized human airway epithelial cells exposed to single-walled carbon nanotubes (SWCNT). In this study, we examined whether multi-walled carbon nanotubes (MWCNT) cause mitotic spindle damage in cultured cells at doses equivalent to 34 years of exposure at the NIOSH Recommended Exposure Limit (REL). MWCNT induced a dose responsive increase in disrupted centrosomes, abnormal mitotic spindles and aneuploid chromosome number 24 hours after exposure to 0.024, 0.24, 2.4 and 24 μg/cm² MWCNT. Monopolar mitotic spindles comprised 95% of disrupted mitoses. Three-dimensional reconstructions of 0.1 μm optical sections showed carbon nanotubes integrated with microtubules, DNA and within the centrosome structure. Cell cycle analysis demonstrated a greater number of cells in S-phase and fewer cells in the G2 phase in MWCNT-treated compared to diluent control, indicating a G1/S block in the cell cycle. The monopolar phenotype of the disrupted mitotic spindles and the G1/S block in the cell cycle is in sharp contrast to the multi-polar spindle and G2 block in the cell cycle previously observed following exposure to SWCNT. One month following exposure to MWCNT there was a dramatic increase in both size and number of colonies compared to diluent control cultures, indicating a potential to pass the genetic damage to daughter cells. Our results demonstrate significant disruption of the mitotic spindle by MWCNT at occupationally relevant exposure levels.

  19. Genotoxicity of multi-walled carbon nanotubes at occupationally relevant doses

    PubMed Central

    2014-01-01

    Carbon nanotubes are commercially-important products of nanotechnology; however, their low density and small size makes carbon nanotube respiratory exposures likely during their production or processing. We have previously shown mitotic spindle aberrations in cultured primary and immortalized human airway epithelial cells exposed to single-walled carbon nanotubes (SWCNT). In this study, we examined whether multi-walled carbon nanotubes (MWCNT) cause mitotic spindle damage in cultured cells at doses equivalent to 34 years of exposure at the NIOSH Recommended Exposure Limit (REL). MWCNT induced a dose responsive increase in disrupted centrosomes, abnormal mitotic spindles and aneuploid chromosome number 24 hours after exposure to 0.024, 0.24, 2.4 and 24 μg/cm2 MWCNT. Monopolar mitotic spindles comprised 95% of disrupted mitoses. Three-dimensional reconstructions of 0.1 μm optical sections showed carbon nanotubes integrated with microtubules, DNA and within the centrosome structure. Cell cycle analysis demonstrated a greater number of cells in S-phase and fewer cells in the G2 phase in MWCNT-treated compared to diluent control, indicating a G1/S block in the cell cycle. The monopolar phenotype of the disrupted mitotic spindles and the G1/S block in the cell cycle is in sharp contrast to the multi-polar spindle and G2 block in the cell cycle previously observed following exposure to SWCNT. One month following exposure to MWCNT there was a dramatic increase in both size and number of colonies compared to diluent control cultures, indicating a potential to pass the genetic damage to daughter cells. Our results demonstrate significant disruption of the mitotic spindle by MWCNT at occupationally relevant exposure levels. PMID:24479647

  20. Cucurbitacin-I inhibits Aurora kinase A, Aurora kinase B and survivin, induces defects in cell cycle progression and promotes ABT-737-induced cell death in a caspase-independent manner in malignant human glioma cells.

    PubMed

    Premkumar, Daniel R; Jane, Esther P; Pollack, Ian F

    2015-01-01

    Because STAT signaling is commonly activated in malignant gliomas as a result of constitutive EGFR activation, strategies for inhibiting the EGFR/JAK/STAT cascade are of significant interest. We, therefore, treated a panel of established glioma cell lines, including EGFR overexpressors, and primary cultures derived from patients diagnosed with glioblastoma with the JAK/STAT inhibitor cucurbitacin-I. Treatment with cucurbitacin-I depleted p-STAT3, p-STAT5, p-JAK1 and p-JAK2 levels, inhibited cell proliferation, and induced G2/M accumulation, DNA endoreduplication, and multipolar mitotic spindles. Longer exposure to cucurbitacin-I significantly reduced the number of viable cells and this decrease in viability was associated with cell death, as confirmed by an increase in the subG1 fraction. Our data also demonstrated that cucurbitacin-I strikingly downregulated Aurora kinase A, Aurora kinase B and survivin. We then searched for agents that exhibited a synergistic effect on cell death in combination with cucurbitacin-I. We found that cotreatment with cucurbitacin-I significantly increased Bcl(-)2/Bcl(-)xL family member antagonist ABT-737-induced cell death regardless of EGFR/PTEN/p53 status of malignant human glioma cell lines. Although >50% of the cucurbitacin-I plus ABT-737 treated cells were annexin V and propidium iodide positive, PARP cleavage or caspase activation was not observed. Pretreatment of z-VAD-fmk, a pan caspase inhibitor did not inhibit cell death, suggesting a caspase-independent mechanism of cell death. Genetic inhibition of Aurora kinase A or Aurora kinase B or survivin by RNA interference also sensitized glioma cells to ABT-737, suggesting a link between STAT activation and Aurora kinases in malignant gliomas.

  1. Exercise-Induced Bronchoconstriction

    MedlinePlus

    ... Conditions & Treatments ▸ Conditions Dictionary ▸ Exercise-Induced Bronchoconstriction Share | Exercise-Induced Bronchoconstriction (EIB) « Back to A to Z Listing Exercise-Induced Bronchoconstriction, (EIB), often known as exercise-induced ...

  2. Curcumin affects components of the chromosomal passenger complex and induces mitotic catastrophe in apoptosis-resistant Bcr-Abl-expressing cells.

    PubMed

    Wolanin, Kamila; Magalska, Adriana; Mosieniak, Grazyna; Klinger, Rut; McKenna, Sharon; Vejda, Susanne; Sikora, Ewa; Piwocka, Katarzyna

    2006-07-01

    The Bcr-Abl oncoprotein plays a major role in the development and progression of chronic myeloid leukemia and is a determinant of chemotherapy resistance occurring during the blast crisis phase of the disease. The aim of this article was to investigate the possibility of combating the resistance to apoptosis caused by Bcr-Abl by inducing an alternative cell death process. As a model of chronic myeloid leukemia, we employed Bcr-Abl-transfected mouse progenitor 32D cells with low and high Bcr-Abl expression levels corresponding to drug-sensitive and drug-resistant cells, respectively. The drug curcumin (diferuloylmethane), a known potent inducer of cell death in many cancer cells, was investigated for efficacy with Bcr-Abl-expressing cells. Curcumin strongly inhibited cell proliferation and affected cell viability by inducing apoptotic symptoms in all tested cells; however, apoptosis was a relatively late event. G(2)-M cell cycle arrest, together with increased mitotic index and cellular and nuclear morphology resembling those described for mitotic catastrophe, was observed and preceded caspase-3 activation and DNA fragmentation. Mitosis-arrested cells displayed abnormal chromatin organization, multipolar chromosome segregation, aberrant cytokinesis, and multinucleated cells-morphologic changes typical of mitotic catastrophe. We found that the mitotic cell death symptoms correlated with attenuated expression of survivin, a member of the chromosomal passenger complex, and mislocalization of Aurora B, the partner of survivin in the chromosomal passenger complex. Inhibition of survivin expression with small interfering RNA exhibited similar mitotic disturbances, thus implicating survivin as a major, albeit not the only, target for curcumin action. This study shows that curcumin can overcome the broad resistance to cell death caused by expression of Bcr-Abl and suggests that curcumin may be a promising agent for new combination regimens for drug-resistant chronic myeloid

  3. Exercise-Induced Asthma

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Exercise-Induced Asthma KidsHealth > For Parents > Exercise-Induced Asthma ... they choose. previous continue Tips for Kids With Exercise-Induced Asthma For the most part, kids with ...

  4. Proteomic profiling revealed the functional networks associated with mitotic catastrophe of HepG2 hepatoma cells induced by 6-bromine-5-hydroxy-4-methoxybenzaldehyde

    SciTech Connect

    Zhang Bo; Huang Bo; Guan Hua; Zhang Shimeng; Xu Qinzhi; He Xingpeng; Liu Xiaodan; Wang Yu; Shang Zengfu; Zhou Pingkun

    2011-05-01

    Mitotic catastrophe, a form of cell death resulting from abnormal mitosis, is a cytotoxic death pathway as well as an appealing mechanistic strategy for the development of anti-cancer drugs. In this study, 6-bromine-5-hydroxy-4-methoxybenzaldehyde was demonstrated to induce DNA double-strand break, multipolar spindles, sustain mitotic arrest and generate multinucleated cells, all of which indicate mitotic catastrophe, in human hepatoma HepG2 cells. We used proteomic profiling to identify the differentially expressed proteins underlying mitotic catastrophe. A total of 137 differentially expressed proteins (76 upregulated and 61 downregulated proteins) were identified. Some of the changed proteins have previously been associated with mitotic catastrophe, such as DNA-PKcs, FoxM1, RCC1, cyclin E, PLK1-pT210, 14-3-3{sigma} and HSP70. Multiple isoforms of 14-3-3, heat-shock proteins and tubulin were upregulated. Analysis of functional significance revealed that the 14-3-3-mediated signaling network was the most significantly enriched for the differentially expressed proteins. The modulated proteins were found to be involved in macromolecule complex assembly, cell death, cell cycle, chromatin remodeling and DNA repair, tubulin and cytoskeletal organization. These findings revealed the overall molecular events and functional signaling networks associated with spindle disruption and mitotic catastrophe. - Graphical abstract: Display Omitted Research highlights: > 6-bromoisovanillin induced spindle disruption and sustained mitotic arrest, consequently resulted in mitotic catastrophe. > Proteomic profiling identified 137 differentially expressed proteins associated mitotic catastrophe. > The 14-3-3-mediated signaling network was the most significantly enriched for the altered proteins. > The macromolecule complex assembly, cell cycle, chromatin remodeling and DNA repair, tubulin organization were also shown involved in mitotic catastrophe.

  5. Morphology of microvascular changes and endothelial regeneration in experimental ozone-induced parathyroiditis. III. Some pathologic considerations

    SciTech Connect

    Atwal, O.S.; Pemsingh, R.S.

    1981-03-01

    Proliferation of the vascular endothelium of the parathyroid glands of dogs exposed to ozone inhalation was studied. Direct observation of mitoses in the endothelial cells were made. Focal hemorrhages in the form of the presence of erythrocytes, clotting, and fibrin deposition in the extravascular spaces were seen. Ultrastructural analysis of transverse section of blood vessels showed intravascular platelet aggregation. Lymphoid cells were observed in the lumen of the blood vessels as well as in the perivascular areas as infiltrates. The possibility is discussed that present vascular reactions signify the morphologic equivalent of an immunologic response.

  6. T Cells' Immunological Synapses Induce Polarization of Brain Astrocytes In Vivo and In Vitro: A Novel Astrocyte Response Mechanism to Cellular Injury

    PubMed Central

    Barcia, Carlos; Sanderson, Nicholas S. R.; Barrett, Robert J.; Wawrowsky, Kolja; Kroeger, Kurt M.; Puntel, Mariana; Liu, Chunyan; Castro, Maria G.; Lowenstein, Pedro R.

    2008-01-01

    Background Astrocytes usually respond to trauma, stroke, or neurodegeneration by undergoing cellular hypertrophy, yet, their response to a specific immune attack by T cells is poorly understood. Effector T cells establish specific contacts with target cells, known as immunological synapses, during clearance of virally infected cells from the brain. Immunological synapses mediate intercellular communication between T cells and target cells, both in vitro and in vivo. How target virally infected astrocytes respond to the formation of immunological synapses established by effector T cells is unknown. Findings Herein we demonstrate that, as a consequence of T cell attack, infected astrocytes undergo dramatic morphological changes. From normally multipolar cells, they become unipolar, extending a major protrusion towards the immunological synapse formed by the effector T cells, and withdrawing most of their finer processes. Thus, target astrocytes become polarized towards the contacting T cells. The MTOC, the organizer of cell polarity, is localized to the base of the protrusion, and Golgi stacks are distributed throughout the protrusion, reaching distally towards the immunological synapse. Thus, rather than causing astrocyte hypertrophy, antiviral T cells cause a major structural reorganization of target virally infected astrocytes. Conclusions Astrocyte polarization, as opposed to hypertrophy, in response to T cell attack may be due to T cells providing a very focused attack, and thus, astrocytes responding in a polarized manner. A similar polarization of Golgi stacks towards contacting T cells was also detected using an in vitro allogeneic model. Thus, different T cells are able to induce polarization of target astrocytes. Polarization of target astrocytes in response to immunological synapses may play an important role in regulating the outcome of the response of astrocytes to attacking effector T cells, whether during antiviral (e.g. infected during HIV, HTLV-1

  7. Cavitation-resistant inducer

    DOEpatents

    Dunn, Charlton; Subbaraman, Maria R.

    1989-01-01

    An improvement in an inducer for a pump wherein the inducer includes a hub, a plurality of radially extending substantially helical blades and a wall member extending about and encompassing an outer periphery of the blades. The improvement comprises forming adjacent pairs of blades and the hub to provide a substantially rectangular cross-sectional flow area which cross-sectional flow area decreases from the inlet end of the inducer to a discharge end of the inducer, resulting in increased inducer efficiency improved suction performance, reduced susceptibility to cavitation, reduced susceptibility to hub separation and reduced fabrication costs.

  8. Cavitation-resistant inducer

    DOEpatents

    Dunn, C.; Subbaraman, M.R.

    1989-06-13

    An improvement in an inducer for a pump is disclosed wherein the inducer includes a hub, a plurality of radially extending substantially helical blades and a wall member extending about and encompassing an outer periphery of the blades. The improvement comprises forming adjacent pairs of blades and the hub to provide a substantially rectangular cross-sectional flow area which cross-sectional flow area decreases from the inlet end of the inducer to a discharge end of the inducer, resulting in increased inducer efficiency improved suction performance, reduced susceptibility to cavitation, reduced susceptibility to hub separation and reduced fabrication costs. 11 figs.

  9. The good, the bad and the ugly: the practical consequences of centrosome amplification.

    PubMed

    Sluder, Greenfield; Nordberg, Joshua J

    2004-02-01

    Centrosome amplification (the presence of more than two centrosomes at mitosis) is characteristic of many human cancers. Extra centrosomes can cause the assembly of multipolar spindles, which unequally distribute chromosomes to daughter cells; the resulting genetic imbalances may contribute to cellular transformation. However, this raises the question of how a population of cells with centrosome amplification can survive such chaotic mitoses without soon becoming non-viable as a result of chromosome loss. Recent observations indicate that a variety of mechanisms partially mute the practical consequences of centrosome amplification. Consequently, populations of cells propagate with good efficiency, despite centrosome amplification, yet have an elevated mitotic error rate that can fuel the evolution of the transformed state.

  10. Merlin/ERM proteins establish cortical asymmetry and centrosome position

    PubMed Central

    Hebert, Alan M.; DuBoff, Brian; Casaletto, Jessica B.; Gladden, Andrew B.; McClatchey, Andrea I.

    2012-01-01

    The ability to generate asymmetry at the cell cortex underlies cell polarization and asymmetric cell division. Here we demonstrate a novel role for the tumor suppressor Merlin and closely related ERM proteins (Ezrin, Radixin, and Moesin) in generating cortical asymmetry in the absence of external cues. Our data reveal that Merlin functions to restrict the cortical distribution of the actin regulator Ezrin, which in turn positions the interphase centrosome in single epithelial cells and three-dimensional organotypic cultures. In the absence of Merlin, ectopic cortical Ezrin yields mispositioned centrosomes, misoriented spindles, and aberrant epithelial architecture. Furthermore, in tumor cells with centrosome amplification, the failure to restrict cortical Ezrin abolishes centrosome clustering, yielding multipolar mitoses. These data uncover fundamental roles for Merlin/ERM proteins in spatiotemporally organizing the cell cortex and suggest that Merlin's role in restricting cortical Ezrin may contribute to tumorigenesis by disrupting cell polarity, spindle orientation, and, potentially, genome stability. PMID:23249734

  11. Flumazenil-induced ballism.

    PubMed

    Kim, Joong-Seok; Ko, Seok-Bum; Choi, Yeong-Bin; Lee, Kwang-Soo

    2003-04-01

    Flumazenil, an imidazobenzodiazepine, is the first benzodiazepine antagonist and is being used to reverse the adverse pharmacological effects of benzodiazepine. There have been a few reports on the central nevous system side effects with its use. We report a patient with generalized ballism following administration of flumazenil. The mechanism through which flumazenil induced this symptom is unknown. It is conceivable that flumazenil may antagonize the GABA-benzodiazepine receptor complex and induce dopamine hypersensitivity, thus induce dyskinesic symptoms.

  12. Flumazenil-induced ballism.

    PubMed Central

    Kim, Joong-Seok; Ko, Seok-Bum; Choi, Yeong-Bin; Lee, Kwang-Soo

    2003-01-01

    Flumazenil, an imidazobenzodiazepine, is the first benzodiazepine antagonist and is being used to reverse the adverse pharmacological effects of benzodiazepine. There have been a few reports on the central nevous system side effects with its use. We report a patient with generalized ballism following administration of flumazenil. The mechanism through which flumazenil induced this symptom is unknown. It is conceivable that flumazenil may antagonize the GABA-benzodiazepine receptor complex and induce dopamine hypersensitivity, thus induce dyskinesic symptoms. PMID:12692435

  13. Drug-induced nephropathies.

    PubMed

    Paueksakon, Paisit; Fogo, Agnes B

    2017-01-01

    Drugs are associated frequently with the development of various types of acute and chronic kidney diseases. Nephrotoxicity is associated most commonly with injury in the tubulointerstitial compartment manifested as either acute tubular injury or acute interstitial nephritis. A growing number of reports has also highlighted the potential for drug-induced glomerular disease, including direct cellular injury and immune-mediated injury. Recognition of drug-induced nephropathies and rapid discontinuation of the offending agents are critical to maximizing the likelihood of renal function recovery. This review will focus on the pathology and pathogenesis of drug-induced acute interstitial nephritis and drug-induced glomerular diseases.

  14. Microcystin-LR, a protein phosphatase inhibitor, induces alterations in mitotic chromatin and microtubule organization leading to the formation of micronuclei in Vicia faba

    PubMed Central

    Beyer, Dániel; Tándor, Ildikó; Kónya, Zoltán; Bátori, Róbert; Roszik, Janos; Vereb, György; Erdődi, Ferenc; Vasas, Gábor; M-Hamvas, Márta; Jambrovics, Károly; Máthé, Csaba

    2012-01-01

    Background and Aims Microcystin-LR (MCY-LR) is a cyanobacterial toxin, a specific inhibitor of type 1 and 2A protein phosphatases (PP1 and PP2A) with significant impact on aquatic ecosystems. It has the potential to alter regulation of the plant cell cycle. The aim of this study was improved understanding of the mitotic alterations induced by cyanotoxin in Vicia faba, a model organism for plant cell biology studies. Methods Vicia faba seedlings were treated over the long and short term with MCY-LR purified in our laboratory. Short-term treatments were performed on root meristems synchronized with hydroxylurea. Sections of lateral root tips were labelled for chromatin, phosphorylated histone H3 and β-tubulin via histochemical and immunohistochemical methods. Mitotic activity and the occurrence of mitotic alterations were detected and analysed by fluorescence microscopy. The phosphorylation state of histone H3 was studied by Western blotting. Key Results Long-term MCY-LR exposure of lateral root tip meristems increased the percentage of either early or late mitosis in a concentration-dependent manner. We observed hypercondensed chromosomes and altered sister chromatid segregation (lagging chromosomes) leading to the formation of micronuclei, accompanied by the formation of disrupted, multipolar and monopolar spindles, disrupted phragmoplasts and the hyperphosphorylation of histone H3 at Ser10. Short-term MCY-LR treatment of synchronized cells showed that PP1 and PP2A inhibition delayed the onset of anaphase at 1 µg mL−1 MCY-LR, accelerated cell cycle at 10 µg mL−1 MCY-LR and induced the formation of lagging chromosomes. In this case mitotic microtubule alterations were not detected, but histone H3 was hyperphosphorylated. Conclusions MCY-LR delayed metaphase–anaphase transition. Consequently, it induced aberrant chromatid segregation and micronucleus formation that could be associated with both H3 hyperphosphorylation and altered microtubule organization

  15. Teacher-Induced Errors.

    ERIC Educational Resources Information Center

    Richmond, Kent C.

    Students of English as a second language (ESL) often come to the classroom with little or no experience in writing in any language and with inaccurate assumptions about writing. Rather than correct these assumptions, teachers often seem to unwittingly reinforce them, actually inducing errors into their students' work. Teacher-induced errors occur…

  16. Stress-induced flowering

    PubMed Central

    Wada, Kaede C

    2010-01-01

    Many plant species can be induced to flower by responding to stress factors. The short-day plants Pharbitis nil and Perilla frutescens var. crispa flower under long days in response to the stress of poor nutrition or low-intensity light. Grafting experiments using two varieties of P. nil revealed that a transmissible flowering stimulus is involved in stress-induced flowering. The P. nil and P. frutescens plants that were induced to flower by stress reached anthesis, fruited and produced seeds. These seeds germinated, and the progeny of the stressed plants developed normally. Phenylalanine ammonialyase inhibitors inhibited this stress-induced flowering, and the inhibition was overcome by salicylic acid (SA), suggesting that there is an involvement of SA in stress-induced flowering. PnFT2, a P. nil ortholog of the flowering gene FLOWERING LOCUS T (FT) of Arabidopsis thaliana, was expressed when the P. nil plants were induced to flower under poor-nutrition stress conditions, but expression of PnFT1, another ortholog of FT, was not induced, suggesting that PnFT2 is involved in stress-induced flowering. PMID:20505356

  17. Space Station Induced Monitoring

    NASA Technical Reports Server (NTRS)

    Spann, James F. (Editor); Torr, Marsha R. (Editor)

    1988-01-01

    This report contains the results of a conference convened May 10-11, 1988, to review plans for monitoring the Space Station induced environment, to recommend primary components of an induced environment monitoring package, and to make recommendations pertaining to suggested modifications of the Space Station External Contamination Control Requirements Document JSC 30426. The contents of this report are divided as Follows: Monitoring Induced Environment - Space Station Work Packages Requirements, Neutral Environment, Photon Emission Environment, Particulate Environment, Surface Deposition/Contamination; and Contamination Control Requirements.

  18. Mania Induced by Opipramol

    PubMed Central

    Firoz, Kazhungil; Khaleel, Asfia; Rajmohan, V; Kumar, Manoj; Raghuram, TM

    2015-01-01

    Antidepressants have propensity to induce manic switch in patients with bipolar disorder. Opipramol is an atypical anxiolytic and antidepressant drug which predominantly acts on sigma receptors. Although structurally resembles tricyclic antidepressant imipramine it does not have inhibitory action on the reuptake of norepinephrine/serotonin and hence it is not presumed to cause manic switch in bipolar depression. Here, we describe a case of mania induced by opipramol, in a patient with bipolar affective disorder who was treated for moderate depressive episode with lithium and opipramol and we discuss neurochemical hypothesis of opipramol-induced mania. PMID:25722522

  19. Three-dimensional instability of a multipolar vortex in a rotating flow

    NASA Astrophysics Data System (ADS)

    Le Dizès, Stéphane

    2000-11-01

    In this paper, the elliptic instability is generalized to account for Coriolis effects and higher order symmetries. We consider, in a frame rotating at the angular frequency Ω, a stationary vortex which is described near its center r=0 by the stream function written in polar coordinates Ψ=-(r2/2)+p(rn/n)cos(nθ), where the integer n is the order of the azimuthal symmetry, and p is a small positive parameter which measures the strength of the nonaxisymmetric field. Based on the Lifschitz and Hameiri [Phys. Fluids A 3, 2644-2651 (1991)] theory, the local stability analysis of the streamline Ψ=-1/2 is performed in the limit of small p. As for the elliptic instability [Bayly, Phys. Rev. Lett. 57, 2160-2163 (1986)], the instability is shown to be due to a parametric resonance of inertial waves when the inclination angle ξ of their wave vector with respect to the rotation axis takes a particular value given by cos ξ=±4/(n(1+Ω)). An explicit formula for the maximum growth rate of the inertial wave is obtained for arbitrary ξ, Ω, and n. As an immediate consequence, it is shown that a vortex core of relative vorticity Wr (assumed positive) is locally unstable if Ω<-(1+n/4)Wr/2 or Ω>(-1+n/4-p(n-1)/2)Wr/2. The predictive power of the local theory is demonstrated on several vortex examples by comparing the local stability predictions with global stability results. For both the Kirchhoff vortex and Moore and Saffman vortex, it is shown how global stability results can be derived from the local stability analysis using the dispersion relation of normal (Kelvin) modes. These results are compared to those obtained by global methods and a surprisingly good agreement is demonstrated. The local results are also applied to rotating Stuart vortices and compared to available numerical data.

  20. Energetics of charge transfer reactions in solvents of dipolar and higher order multipolar character. II. Results

    NASA Astrophysics Data System (ADS)

    Perng, Baw-Ching; Newton, Marshall D.; Raineri, Fernando O.; Friedman, Harold L.

    1996-05-01

    We apply the theories developed in the preceding paper (paper I) to calculate various energy quantities of charge transfer (CT) reactions in nine solvents that cover a wide range of polarity, and for which interaction site models (ISM's) may be found in the literature. Besides the two surrogate Hamiltonian theories developed in paper I, the renormalized site-density theory (RST) and the renormalized dielectric theory (RDT), we also investigate a simple harmonic approximation (HXA) for the diabatic free energy profiles, whose characteristic parameters are calculated taking specific advantage of the expression given by the extended reference interaction site method (XRISM) for the free energy of solvation. For each CT process we analyze (a) the solvent reorganization energy λ, (b) the shift of the absorption transition energy due to the solvatochromic effect, and (c) the solvent contribution to the free energy change ΔA. In addition, for a few selected examples, we also report the detailed diabatic free energy profiles. The calculations reported rely on solute-solvent and solvent-solvent pair correlation functions obtained with the XRISM integral equation method applied to nonpolarizable (with fixed mean partial charges) ISM representations of the solute and solvent molecules. To rectify the omission of the solvent electronic degrees of freedom, we correct the dielectric part of the solvent reorganization energy with an additive term designed to compensate for the use of fixed charge ISM models. Contact with theories in which the solvent is represented as a dielectric continuum medium (with or without spatial dispersion) and the solute as a set of charges inside spherical cavities carved out of the dielectric is made straightforwardly within the RDT theory by considering a particularly simple form of the solute-solvent RISM site-site direct correlation functions. Using simple ISM models for several solute species, including Reichardt's betaine-30 dye and a porphyrin-quinone (PQ) ``dyad'' recently studied by Mataga and co-workers, we examine the ability of the molecular theories to explain the dependence of charge-transfer energetics on dipolar and nondipolar solvents. We find that the solvatochromic effect on the absorption energy of betaine-30, which forms the basis of the ET(30) empirical solvent polarity scale, is reproduced reasonably well by the RST, RDT, and HXA theories for solvents ranging from carbon tetrachloride to water. In the case of the PQ dyad, we find that the calculated values of λ in dipolar and nondipolar solvents are in good agreement with experimental estimates. Our results indicate that the molecular theories of solvation discussed in this paper can explain the observation that a solvent with vanishing molecular dipole moment, like benzene, can show unmistakable ``polarity,'' as reflected by its influence on the energetics of CT reactions. We also present calculations that corroborate the suggestion (Sec. VII of paper I) that, compared with the behavior in dipolar solvents, in nondipolar solvents the dependence of λ with the donor-acceptor separation distance is practically negligible.

  1. Experimental investigation of microwave interaction with magnetoplasma in miniature multipolar configuration using impedance measurements

    SciTech Connect

    Dey, Indranuj Toyoda, Yuji; Yamamoto, Naoji; Nakashima, Hideki

    2014-09-15

    A miniature microwave plasma source employing both radial and axial magnetic fields for plasma confinement has been developed for micro-propulsion applications. Plasma is initiated by launching microwaves via a short monopole antenna to circumvent geometrical cutoff limitations. The amplitude and phase of the forward and reflected microwave power is measured to obtain the complex reflection coefficient from which the equivalent impedance of the plasma source is determined. Effect of critical plasma density condition is reflected in the measurements and provides insight into the working of the miniature plasma source. A basic impedance calculation model is developed to help in understanding the experimental observations. From experiment and theory, it is seen that the equivalent impedance magnitude is controlled by the coaxial discharge boundary conditions, and the phase is influenced primarily by the plasma immersed antenna impedance.

  2. Multipolar electrostatics for proteins: atom-atom electrostatic energies in crambin.

    PubMed

    Yuan, Yongna; Mills, Matthew J L; Popelier, Paul L A

    2014-02-15

    Accurate electrostatics necessitates the use of multipole moments centered on nuclei or extra point charges centered away from the nuclei. Here, we follow the former alternative and investigate the convergence behavior of atom-atom electrostatic interactions in the pilot protein crambin. Amino acids are cut out from a Protein Data Bank structure of crambin, as single amino acids, di, or tripeptides, and are then capped with a peptide bond at each side. The atoms in the amino acids are defined through Quantum Chemical Topology (QCT) as finite volume electron density fragments. Atom-atom electrostatic energies are computed by means of a multipole expansion with regular spherical harmonics, up to a total interaction rank of L = ℓA+ ℓB + 1 = 10. The minimum internuclear distance in the convergent region of all the 15 possible types of atom-atom interactions in crambin that were calculated based on single amino acids are close to the values calculated from di and tripeptides. Values obtained at B3LYP/aug-cc-pVTZ and MP2/aug-cc-pVTZ levels are only slightly larger than those calculated at HF/6-31G(d,p) level. This convergence behavior is transferable to the well-known amyloid beta polypeptide Aβ1-42. Moreover, for a selected central atom, the influence of its neighbors on its multipole moments is investigated, and how far away this influence can be ignored is also determined. Finally, the convergence behavior of AMBER becomes closer to that of QCT with increasing internuclear distance.

  3. A DETAILED SPATIOKINEMATIC MODEL OF THE CONICAL OUTFLOW OF THE MULTIPOLAR PLANETARY NEBULA NGC 7026

    SciTech Connect

    Clark, D. M.; Lopez, J. A.; Steffen, W.; Richer, M. G.

    2013-03-15

    We present extensive, long-slit, high-resolution coverage of the complex planetary nebula (PN) NGC 7026. We acquired 10 spectra using the Manchester Echelle Spectrometer at San Pedro Martir Observatory in Baja California, Mexico, and each shows exquisite detail, revealing the intricate structure of this object. Incorporating these spectra into the three-dimensional visualization and kinematic program SHAPE and using Hubble Space Telescope images of NGC 7026, we have produced a detailed structural and kinematic model of this PN. NGC 7026 exhibits remarkable symmetry consisting of three lobe pairs and four sets of knots, all symmetrical about the nucleus and displaying a conical outflow. Comparing the three-dimensional structure of this nebula to recent XMM-Newton X-ray observations, we investigate the extended X-ray emission in relation to the nebular structure. We find that the X-ray emission, while confined to the closed, northern lobes of this PN, shows an abrupt termination in the middle of the southeast lobe, which our long slit data show to be open. This is where the shocked fast wind seems to be escaping the interior of the nebula and the X-ray emission rapidly cools in this region.

  4. Reducing Insertion Sites of Penetrating Multipolar Shaft Electrodes by Double Side Electrode Arrangement

    DTIC Science & Technology

    2007-11-02

    for Implantable Biomedical Microdevices ,“ Proc. MICRO.tec 2000, Hannover, Germany, 2000, pp. 277-281. [5] T. Stieglitz, “Flexible Biomedical ... Microdevices with Dou- ble-Sided Electrode Arrangements for Neural Applications“, Sens & Act. A-Physical, (in press 2001).

  5. Crystal design using multipolar electrostatic interactions: A concept study for organic electronics

    PubMed Central

    Tong, Qiong; Untenecker, Harald

    2013-01-01

    Summary Using a simple synthetic protocol, heterohexacene analogues with a quadrupolar distribution of partial charges are readily available. In contrast to most other acenes, these compounds crystallize with a slipped-stack, brickwork-like packing which is mainly controlled by electrostatic interactions. This type of packing offers an advantage for organic semiconductors, because it allows more isotropic charge transport compared to the “herring bone” stacking observed for other acenes. PMID:24367401

  6. Unified approach to multipolar polarisation and charge transfer for ions: microhydrated Na+.

    PubMed

    Mills, Matthew J L; Hawe, Glenn I; Handley, Christopher M; Popelier, Paul L A

    2013-11-07

    Electrostatic effects play a large part in determining the properties of chemical systems. In addition, a treatment of the polarisation of the electron distribution is important for many systems, including solutions of monatomic ions. Typically employed methods for describing polarisable electrostatics use a number of approximations, including atom-centred point charges and polarisation methods that require iterative calculation on the fly. We present a method that treats charge transfer and polarisation on an equal footing. Atom-centred multipole moments describe the charge distribution of a chemical system. The variation of these multipole moments with the geometry of the surrounding atoms is captured by the machine learning method kriging. The interatomic electrostatic interaction can be computed using the resulting predicted multipole moments. This allows the treatment of both intra- and interatomic polarisation with the same method. The proposed method does not return explicit polarisabilities but instead, predicts the result of the polarisation process. An application of this new method to the sodium cation in a water environment is described. The performance of the method is assessed by comparison of its predictions of atomic multipole moments and atom-atom electrostatic interaction energies to exact results. The kriging models are able to predict the electrostatic interaction energy between the ion and all water atoms within 4 kJ mol(-1) for any of the external test set Na(+)(H2O)6 configurations.

  7. Realistic sampling of amino acid geometries for a multipolar polarizable force field.

    PubMed

    Hughes, Timothy J; Cardamone, Salvatore; Popelier, Paul L A

    2015-09-15

    The Quantum Chemical Topological Force Field (QCTFF) uses the machine learning method kriging to map atomic multipole moments to the coordinates of all atoms in the molecular system. It is important that kriging operates on relevant and realistic training sets of molecular geometries. Therefore, we sampled single amino acid geometries directly from protein crystal structures stored in the Protein Databank (PDB). This sampling enhances the conformational realism (in terms of dihedral angles) of the training geometries. However, these geometries can be fraught with inaccurate bond lengths and valence angles due to artefacts of the refinement process of the X-ray diffraction patterns, combined with experimentally invisible hydrogen atoms. This is why we developed a hybrid PDB/nonstationary normal modes (NM) sampling approach called PDB/NM. This method is superior over standard NM sampling, which captures only geometries optimized from the stationary points of single amino acids in the gas phase. Indeed, PDB/NM combines the sampling of relevant dihedral angles with chemically correct local geometries. Geometries sampled using PDB/NM were used to build kriging models for alanine and lysine, and their prediction accuracy was compared to models built from geometries sampled from three other sampling approaches. Bond length variation, as opposed to variation in dihedral angles, puts pressure on prediction accuracy, potentially lowering it. Hence, the larger coverage of dihedral angles of the PDB/NM method does not deteriorate the predictive accuracy of kriging models, compared to the NM sampling around local energetic minima used so far in the development of QCTFF.

  8. Surface Ship Classification Using Multipolarization, Multifrequency Sky-Wave Resonance Radar

    DTIC Science & Technology

    1984-10-01

    November 1974. [14] H.L. Van Trees, Detection, Estimation, and Modulation Thoery , Part I, John Wiley & Sons, New York, 1968. [15] A. Papoulis, Signal... STRING (22) E*UIVALBCE(LINEI(1j,BUFF(1)),(LINE2(l),BUFF(51i), DIMENSIONM ARA(3OJCMJ E6M) )WO CFT=9.83SE+0a NP=-N C KRPTr in a counter which stops the...and of string IF[LINEIB)(I:I).NE. 𔃻) THEN I Find Length of string "-3 340 ,*? ’!t~., *~A-. *~ SOTO 53 END IF END D0 53 ENCODE(15,103 9, TLINE) NS I

  9. Controlling multipolar surface plasmon excitation through the azimuthal phase structure of electron vortex beams

    NASA Astrophysics Data System (ADS)

    Ugarte, Daniel; Ducati, Caterina

    2016-05-01

    We have theoretically studied how the azimuthal phase structure of an electron vortex beam excites surface plasmons on metal particles of different geometries as observed in electron energy loss spectroscopy (EELS). We have developed a semiclassical approximation combining a ring-shaped beam and the dielectric formalism. Our results indicate that for the case of total orbital angular momentum transfer, we can manipulate surface plasmon multipole excitation and even attain an enhancement factor of several orders of magnitude. Since electron vortex beams interact with particles mostly through effects due to azimuthal symmetry, i.e., in the plane perpendicular to the electron beam, anisotropy information (longitudinal and transversal) of the sample may be derived in EELS studies by comparing nonvortex and vortex beam measurements.

  10. Multi-polarization C-band SAR for soil moisture estimation

    NASA Technical Reports Server (NTRS)

    Brown, R. J.; Brisco, B.

    1991-01-01

    Previous studies of synthetic aperture radar (SAR) imagery have shown qualitative relationships between radar backscatter and soil moisture. However, to be able to use these data in operational programs it will be necessary to establish quantitatively how the radar return is related to soil moisture and the effects of surface roughness, soil type, and vegetation cover and growth stage, as a function of frequency and polarization. To this end, a multi-year experiment began in 1990 as a cooperative venture amongst the Canada Center (Agriculture Canada), and the Universities of Guelph, Sherbrooke, Laval, and Waterloo. During 1990, SAR imagery was acquired during two periods (May and Jun.) to correspond to times of minimal and substantial vegetation cover. SAR data were acquired on three days in May and on four days in Jul. to cover different soil moisture conditions. This unique comprehensive data set is used to investigate the relationships between soil moisture and radar backscatter. The experiment and data collected are described, and a preliminary qualitative interpretation of the relationship between soil moisture and image tone is provided.

  11. Realistic sampling of amino acid geometries for a multipolar polarizable force field

    PubMed Central

    Hughes, Timothy J.; Cardamone, Salvatore

    2015-01-01

    The Quantum Chemical Topological Force Field (QCTFF) uses the machine learning method kriging to map atomic multipole moments to the coordinates of all atoms in the molecular system. It is important that kriging operates on relevant and realistic training sets of molecular geometries. Therefore, we sampled single amino acid geometries directly from protein crystal structures stored in the Protein Databank (PDB). This sampling enhances the conformational realism (in terms of dihedral angles) of the training geometries. However, these geometries can be fraught with inaccurate bond lengths and valence angles due to artefacts of the refinement process of the X‐ray diffraction patterns, combined with experimentally invisible hydrogen atoms. This is why we developed a hybrid PDB/nonstationary normal modes (NM) sampling approach called PDB/NM. This method is superior over standard NM sampling, which captures only geometries optimized from the stationary points of single amino acids in the gas phase. Indeed, PDB/NM combines the sampling of relevant dihedral angles with chemically correct local geometries. Geometries sampled using PDB/NM were used to build kriging models for alanine and lysine, and their prediction accuracy was compared to models built from geometries sampled from three other sampling approaches. Bond length variation, as opposed to variation in dihedral angles, puts pressure on prediction accuracy, potentially lowering it. Hence, the larger coverage of dihedral angles of the PDB/NM method does not deteriorate the predictive accuracy of kriging models, compared to the NM sampling around local energetic minima used so far in the development of QCTFF. © 2015 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. PMID:26235784

  12. Detecting forest structure and biomass with C-band multipolarization radar - Physical model and field tests

    NASA Technical Reports Server (NTRS)

    Westman, Walter E.; Paris, Jack F.

    1987-01-01

    The ability of C-band radar (4.75 GHz) to discriminate features of forest structure, including biomass, is tested using a truck-mounted scatterometer for field tests on a 1.5-3.0 m pygmy forest of cypress (Cupressus pygmaea) and pine (Pinus contorta ssp, Bolanderi) near Mendocino, CA. In all, 31 structural variables of the forest are quantified at seven sites. Also measured was the backscatter from a life-sized physical model of the pygmy forest, composed of nine wooden trees with 'leafy branches' of sponge-wrapped dowels. This model enabled independent testing of the effects of stem, branch, and leafy branch biomass, branch angle, and moisture content on radar backscatter. Field results suggested that surface area of leaves played a greater role in leaf scattering properties than leaf biomass per se. Tree leaf area index was strongly correlated with vertically polarized power backscatter (r = 0.94; P less than 0.01). Field results suggested that the scattering role of leaf water is enhanced as leaf surface area per unit leaf mass increases; i.e., as the moist scattering surfaces become more dispersed. Fog condensate caused a measurable rise in forest backscatter, both from surface and internal rises in water content. Tree branch mass per unit area was highly correlated with cross-polarized backscatter in the field (r = 0.93; P less than 0.01), a result also seen in the physical model.

  13. Multifrequency and multipolarization radar scatterometry of sand dunes and comparison with spaceborne and airborne radar images

    NASA Technical Reports Server (NTRS)

    Blom, Ronald; Elachi, Charles

    1987-01-01

    Airborne radar scatterometer data on sand dunes, acquired at multiple frequencies and polarizations, are reported. Radar backscatter from sand dunes is very sensitive to the imaging geometry. At small incidence angles the radar return is mainly due to quasi-specular reflection from dune slopes favorably oriented toward the radar. A peak return usually occurs at the incidence angle equal to the angle of repose for the dunes. The peak angle is the same at all frequencies as computed from specular reflection theory. At larger angles the return is significantly weaker. The scatterometer measurements verified observations made with airborne and spaceborne radar images acquired over a number of dune fields in the U.S., central Africa, and the Arabian peninsula. The imaging geometry constraints indicate that possible dunes on other planets, such as Venus, will probably not be detected in radar images unless the incidence angle is less than the angles of repose of such dunes and the radar look direction is approximately orthogonal to the dune trends.

  14. Searching for Surficial Deposits on Venus Using Multi-Polarization Radar

    NASA Technical Reports Server (NTRS)

    Carter, Lynn M.; Campbell, Donald B.; Campbell, Bruce A.; Margot, Jean-Luc

    2003-01-01

    Introduction. The Magellan spacecraft returned hundreds of images of craters, radardark halos, and wind features on Venus. It is clear that surficial layers are associated with some of these features; for example, 59 of the craters have parabolic shaped deposits that are thought to be a few centimeters to a meter in thickness. Magellan also revealed about 400 radar dark "splotches" that may be places where a smooth rubble layer was formed when the shock wave from an impactor hit the surface and crushed the rock. Two dune fields and several areas of microdunes were identified in Magellan data, as well a few thousand windstreaks, so it is clear that dust is transported and redeposited by wind. Thin surficial layers that are not clearly visible in the Magellan imagery may be present in other regions as well. In fact, many surfaces on Venus that were imaged by Magellan SAR may look much different when viewed at optical wavelengths, since radar waves penetrate surface layers and show details of the underlying terrain. A good example is the L-Band (24 cm wavelength) shuttle imaging radar (SIRA) observations by McKauley et al. who detected buried river valleys in the Arbain Desert in southern Egypt.

  15. Generation of trisomies in cancer cells by multipolar mitosis and incomplete cytokinesis

    PubMed Central

    Gisselsson, David; Jin, Yuesheng; Lindgren, David; Persson, Johan; Gisselsson, Lennart; Hanks, Sandra; Sehic, Daniel; Mengelbier, Linda Holmquist; Øra, Ingrid; Rahman, Nazneen; Mertens, Fredrik; Mitelman, Felix; Mandahl, Nils

    2010-01-01

    One extra chromosome copy (i.e., trisomy) is the most common type of chromosome aberration in cancer cells. The mechanisms behind the generation of trisomies in tumor cells are largely unknown, although it has been suggested that dysfunction of the spindle assembly checkpoint (SAC) leads to an accumulation of trisomies through failure to correctly segregate sister chromatids in successive cell divisions. By using Wilms tumor as a model for cancers with trisomies, we now show that trisomic cells can form even in the presence of a functional SAC through tripolar cell divisions in which sister chromatid separation proceeds in a regular fashion, but cytokinesis failure nevertheless leads to an asymmetrical segregation of chromosomes into two daughter cells. A model for the generation of trisomies by such asymmetrical cell division accurately predicted several features of clones having extra chromosomes in vivo, including the ratio between trisomies and tetrasomies and the observation that different trisomies found in the same tumor occupy identical proportions of cells and colocalize in tumor tissue. Our findings provide an experimentally validated model explaining how multiple trisomies can occur in tumor cells that still maintain accurate sister chromatid separation at metaphase–anaphase transition and thereby physiologically satisfy the SAC. PMID:21059955

  16. On the Effects of Imaging Geometry on Multipolarization SAR Features for Oil Spill Observation

    NASA Astrophysics Data System (ADS)

    Skrunes, Stine; Jones, Cathleen E.; Brekke, Camilla; Holt, Benjamin; Espeseth, Martine M.

    2016-08-01

    Polarimetric SAR is increasingly used for oil spill observation. In order to develop reliable methods for oil spill detection and characterization, the sensitivity of these measurements to the imaging geometry, including incidence angle and look direction relative to the wind, must be investigated. In this paper, we study the effects of these parameters on L-band SAR data collected with the UAVSAR instrument over experimental oil spills. The relative look direction is found to have a larger effect on the slick detectability than the incidence angle, and the detectability is better in the downwind direction compared to upwind. The features showing the best slick detectability in the conditions investigated here are the VV intensity, HV intensity, the geometric intensity and the polarization difference. The latter feature shows low dependency on imaging geometry.

  17. United States-Gulf Cooperation Council Security Cooperation in a Multipolar World

    DTIC Science & Technology

    2014-10-01

    to Asia.49 The mar- ket for GCC exports in liquefied natural gas —coming from Qatar, Abu Dhabi, and Oman—is even more concentrated, where above 95...Kuwait, and the UAE. GCC exporters supply more than a quarter of Japanese and Korean liquefied natural gas (LNG), and around a fifth of Chinese LNG...its natural gas ,1 the Gulf states continue to supply world markets with an important share of their energy supplies. Continuing to be one of the

  18. Multi-Frequency and Multi-Polarization Scattering Analysis for Model-Based Coastal Areas Classification

    NASA Astrophysics Data System (ADS)

    Buono, A.; Nunziata, F.; Migliaccio, M.; Li, X.; Wei, Y.; Shen, D.

    2016-08-01

    The Yellow River (in Chinese, Huang He) is the most sediment-filled river and the sixth-longest one in the world. The Yellow River is of paramount importance for safe navigation, local economy and environment due to the presence of floods, farms, aquacultures and pollution. Nonetheless, its delta area it is characterized by of several physical phenomena due to both natural and anthropogenic processes: sedimentation, erosion, floods, pollution, etc.In this study, actual partially overlapped L-/C-band FP SAR data collected from Radarsat-2 and ALOS PalSAR-2, respectively, are used to investigate the scattering properties of the Yellow River delta, whose very challenging area is characterized by different scenarios as recorded by ground truth data acquired during an in-situ campaign. 10 different classes have been codified: sea, river, forest, pond, swamp, tide-land, sand, saline soil, rural and industrial urban areas. However, no ground truth data is available in some codified areas.

  19. Multipolar universal relations between f -mode frequency and tidal deformability of compact stars

    NASA Astrophysics Data System (ADS)

    Chan, T. K.; Sham, Y.-H.; Leung, P. T.; Lin, L.-M.

    2014-12-01

    Though individual stellar parameters of compact stars usually demonstrate obvious dependence on the equation of state (EOS), EOS-insensitive universal formulas relating these parameters remarkably exist. In the present paper, we explore the interrelationship between two such formulas, namely the f -I relation connecting the f -mode quadrupole oscillation frequency ω2 and the moment of inertia I , and the I -Love-Q relations relating I , the quadrupole tidal deformability λ2, and the quadrupole moment Q , which have been proposed by Lau, Leung, and Lin [Astrophys. J. 714, 1234 (2010)] and Yagi and Yunes [Science 341, 365 (2013)], respectively. A relativistic universal relation between ωl and λl with the same angular momentum l =2 ,3 ,… , the so-called "diagonal f -Love relation" that holds for realistic compact stars and stiff polytropic stars, is unveiled here. An in-depth investigation in the Newtonian limit is further carried out to pinpoint its underlying physical mechanism and hence leads to a unified f -I -Love relation. We reach the conclusion that these EOS-insensitive formulas stem from a common physical origin—compact stars can be considered as quasiincompressible when they react to slow time variations introduced by f -mode oscillations, tidal forces and rotations.

  20. MAGNETAR GIANT FLARES-FLUX ROPE ERUPTIONS IN MULTIPOLAR MAGNETOSPHERIC MAGNETIC FIELDS

    SciTech Connect

    Yu Cong

    2012-09-20

    We address a primary question regarding the physical mechanism that triggers the energy release and initiates the onset of eruptions in the magnetar magnetosphere. Self-consistent stationary, axisymmetric models of the magnetosphere are constructed based on force-free magnetic field configurations that contain a helically twisted force-free flux rope. Depending on the surface magnetic field polarity, there exist two kinds of magnetic field configurations, inverse and normal. For these two kinds of configurations, variations of the flux rope equilibrium height in response to gradual surface physical processes, such as flux injections and crust motions, are carefully examined. We find that equilibrium curves contain two branches: one represents a stable equilibrium branch, and the other an unstable equilibrium branch. As a result, the evolution of the system shows a catastrophic behavior: when the magnetar surface magnetic field evolves slowly, the height of the flux rope would gradually reach a critical value beyond which stable equilibriums can no longer be maintained. Subsequently, the flux rope would lose equilibrium and the gradual quasi-static evolution of the magnetosphere will be replaced by a fast dynamical evolution. In addition to flux injections, the relative motion of active regions would give rise to the catastrophic behavior and lead to magnetic eruptions as well. We propose that a gradual process could lead to a sudden release of magnetosphere energy on a very short dynamical timescale, without being initiated by a sudden fracture in the crust of the magnetar. Some implications of our model are also discussed.

  1. The Importance of Why: An Intelligence Approach for a Multi-Polar World

    DTIC Science & Technology

    2016-04-04

    defines intelligence as the “product resulting from the collection, processing, integration, evaluation, analysis , and interpretation of available...integration, evaluation, analysis , and interpretation of all source data and the preparation of intelligence products in support of known or anticipated...intellectual process of interpreting collected information ( analysis ) and proposing what it means (estimation). Puzzle solving is a deterministic process

  2. The star fish twins: Two young planetary nebulae with extreme multipolar morphology

    NASA Technical Reports Server (NTRS)

    Sahai, R.

    2000-01-01

    We present alpha images of two objects, He 2-47 and M1-37, obtained during a Hubble Space Telescope imaging survey of young planetary nebulae (PNs) selected on the basis of their low-excitation characteristics.

  3. Multi-frequency, multi-polarization SAR and radiometer sea ice classification

    NASA Technical Reports Server (NTRS)

    Drinkwater, Mark R.; Crawford, John P.; Cavalieri, Donald J.

    1991-01-01

    Microwave remotely sensed data were acquired simultaneously in March 1988 over Beaufort, Chukchi, and Bering Sea ice using the JPL multifrequency, polarimetric synthetic aperture radar (SAR), and multifrequency dual-polarization GSFC radiometer. The experiment was conducted as a series of coordinated underflights of the DMSP SSM/I satellite radiometer to validate ice products derived from its radiance values. Concurrent flights by an NRL P-3 aircraft enabled overlapping high-resolution, single-frequency images to be acquired over the same surfaces using a Ka-band scanning microwave radiometer. Precise coregistration to an accuracy of 100 m, +/- 25 m enables comparison of temporally and spatially coincident active and passive microwave datasets. Three-channel polarimetric SAR data are compared with dual-polarized radiometer data at several SSM/I frequencies, showing backscatter signatures to be highly correlated with radiometric temperatures. Further comparisons are used to evaluate ice concentration retrievals and to show how multiparameter datasets can be used to resolve ambiguities present in identifying certain sea ice forms with a single microwave instrument.

  4. Drug-induced catatonia.

    PubMed

    Duggal, Harpreet S; Singh, Ira

    2005-09-01

    Catatonia is a heterogeneous syndrome that varies in etiology, presentation, course and sequelae. Initially conceptualized as a subtype of schizophrenia, catatonia is now recognized to occur not only with other psychiatric conditions but also with medical conditions and drug-induced and toxic states. While drug-induced catatonia is now a recognized entity, most studies club it with catatonia due to general medical conditions or organic catatonia, thus precluding any meaningful interpretation of such cases. The literature on drug-induced catatonia mostly draws from scattered case reports. This article attempts to review the available literature in this realm and integrate the information in an attempt to explore the epidemiology, etiology, mechanism and treatment of drug-induced catatonia.

  5. Exercise-induced asthma

    MedlinePlus

    Wheezing - exercise-induced; Reactive airway disease - exercise ... Having asthma symptoms when you exercise does not mean you cannot or should not exercise. But be aware of your EIA triggers. Cold or dry air may ...

  6. Drug-induced hepatitis

    MedlinePlus

    Toxic hepatitis ... to get liver damage. Some drugs can cause hepatitis with small doses, even if the liver breakdown ... liver. Many different drugs can cause drug-induced hepatitis. Painkillers and fever reducers that contain acetaminophen are ...

  7. Vitiligo, drug induced (image)

    MedlinePlus

    ... this person's face have resulted from drug-induced vitiligo. Loss of melanin, the primary skin pigment, occasionally ... is the case with this individual. The typical vitiligo lesion is flat and depigmented, but maintains the ...

  8. Statin induced myotoxicity.

    PubMed

    Sathasivam, Sivakumar

    2012-06-01

    Statins are an effective treatment for the prevention of cardiovascular diseases and used extensively worldwide. However, myotoxicity induced by statins is a common adverse event and a major barrier to maximising cardiovascular risk reduction. The clinical spectrum of statin induced myotoxicity includes asymptomatic rise in creatine kinase concentration, myalgia, myositis and rhabdomyolysis. In certain cases, the cessation of statin therapy does not result in the resolution of muscular symptoms or the normalization of creatine kinase, raising the possibility of necrotizing autoimmune myopathy. There is increasing understanding and recognition of the pathophysiology and risk factors of statin induced myotoxicity. Careful history and physical examination in conjunction with selected investigations such as creatine kinase measurement, electromyography and muscle biopsy in appropriate clinical scenario help diagnose the condition. The management of statin induced myotoxicity involves statin cessation, the use of alternative lipid lowering agents or treatment regimes, and in the case of necrotizing autoimmune myopathy, immunosuppression.

  9. Glucocorticoid-induced osteonecrosis.

    PubMed

    Weinstein, Robert S

    2012-04-01

    Awareness of the need for prevention of glucocorticoid-induced fractures is growing, but glucocorticoid administration is often overlooked as the most common cause of nontraumatic osteonecrosis. Glucocorticoid-induced osteonecrosis develops in 9-40% of patients receiving long-term therapy although it may also occur with short-term exposure to high doses, after intra-articular injection, and without glucocorticoid-induced osteoporosis. The name, osteonecrosis, is misleading because the primary histopathological lesion is osteocyte apoptosis. Apoptotic osteocytes persist because they are anatomically unavailable for phagocytosis and, with glucocorticoid excess, decreased bone remodeling retards their replacement. Glucocorticoid-induced osteocyte apoptosis, a cumulative and unrepairable defect, uniquely disrupts the mechanosensory function of the osteocyte-lacunar-canalicular system and thus starts the inexorable sequence of events leading to collapse of the femoral head. Current evidence indicates that bisphosphonates may rapidly reduce pain, increase ambulation, and delay joint collapse in patients with osteonecrosis.

  10. Ethionamide-induced Pellagra.

    PubMed

    Gupta, Yashashree; Shah, Ira

    2015-08-01

    Pellagra is a disorder characterized by dermatitis, diarrhea, dementia and eventually death, resulting from a deficiency of niacin or its precursor tryptophan. Ethionamide (a second-line antituberculosis agent)-induced pellagra is rarely encountered in clinical practice. Prompt diagnosis and treatment with nicotinamide can prevent life-threatening complications. To date, only three cases have been reported. We report a 13-year-old girl presenting with ethionamide-induced pellagra that resolved after the administration of niacin.

  11. Levodopa-induced myoclonus.

    PubMed

    Klawans, H L; Goetz, C; Bergen, D

    1975-05-01

    Twelve parkinsonian patients on long-term levodopa therapy developed intermittent, myoclonic body jerks. The movements consisted of single unilateral or bilateral abrupt jerks of the extremities and occurred most frequently during sleep. Although directly related to daily dosage of levodopa, the myoclonus was specifically blocked by the serotonin antagonist, methysergide. Levodopa-induced myoclonus may be related to intermittent increases of activity of serotonin in the brain and results from levodopa-induced dysregulation of serotonin activity.

  12. Induced polarization response of microbial induced sulfideprecipitation

    SciTech Connect

    Ntarlagiannis, Dimitrios; Williams, Kenneth Hurst; Slater, Lee; Hubbard, Susan

    2004-06-04

    A laboratory scale experiment was conducted to examine the use of induced polarization and electrical conductivity to monitor microbial induced sulfide precipitation under anaerobic conditions in sand filled columns. Three columns were fabricated; one for electrical measurements, one for geochemical sampling and a third non-inoculated column was used as a control. A continual upward flow of nutrients and metals in solution was established in each column. Desulfovibrio vulgaris microbes were injected into the middle of the geochemical and electrical columns. Iron and zinc sulfides precipitated along a microbial action front as a result of sulfate reduction due by Desulfovibrio vulgaris. The precipitation front initially developed near the microbial injection location, and subsequently migrated towards the nutrient inlet, as a result of chemotaxis by Desulfovibrio vulgaris. Sampling during and subsequent to the experiment revealed spatiotemporal changes in the biogeochemical measurements associated with microbial sulfate reduction. Conductivity measurements were insensitive to all biogeochemical changes occurred within the column. Changes in the IP response (of up to 14 mrad)were observed to coincide in place and in time with the active microbe respiration/sulfide precipitation front as determined from geochemical sampling. The IP response is correlated with the lactate concentration gradient, an indirect measurement of microbial metabolism, suggesting the potential of IP as a method for monitoring microbial respiration/activity. Post experimental destructive sample analysis and SEM imaging verified the geochemical results and supported our hypothesis that microbe induced sulfide precipitation is directly detectable using electrical methods. Although the processes not fully understood, the IP response appears to be sensitive to this anaerobic microbial precipitation, suggesting a possible novel application for the IP method.

  13. Gravitationally induced quantum transitions

    NASA Astrophysics Data System (ADS)

    Landry, A.; Paranjape, M. B.

    2016-06-01

    In this paper, we calculate the probability for resonantly inducing transitions in quantum states due to time-dependent gravitational perturbations. Contrary to common wisdom, the probability of inducing transitions is not infinitesimally small. We consider a system of ultracold neutrons, which are organized according to the energy levels of the Schrödinger equation in the presence of the Earth's gravitational field. Transitions between energy levels are induced by an oscillating driving force of frequency ω . The driving force is created by oscillating a macroscopic mass in the neighborhood of the system of neutrons. The neutron lifetime is approximately 880 sec while the probability of transitions increases as t2. Hence, the optimal strategy is to drive the system for two lifetimes. The transition amplitude then is of the order of 1.06 ×10-5, and hence with a million ultracold neutrons, one should be able to observe transitions.

  14. Radiation-induced gliomas

    PubMed Central

    Prasad, Gautam; Haas-Kogan, Daphne A.

    2013-01-01

    Radiation-induced gliomas represent a relatively rare but well-characterized entity in the neuro-oncologic literature. Extensive retrospective cohort data in pediatric populations after therapeutic intracranial radiation show a clearly increased risk in glioma incidence that is both patient age- and radiation dose/volume-dependent. Data in adults are more limited but show heightened risk in certain groups exposed to radiation. In both populations, there is no evidence linking increased risk associated with routine exposure to diagnostic radiation. At the molecular level, recent studies have found distinct genetic differences between radiation-induced gliomas and their spontaneously-occurring counterparts. Clinically, there is understandable reluctance on the part of clinicians to re-treat patients due to concern for cumulative neurotoxicity. However, available data suggest that aggressive intervention can lead to improved outcomes in patients with radiation-induced gliomas. PMID:19831840

  15. Drug-induced mania.

    PubMed

    Peet, M; Peters, S

    1995-02-01

    Mania can occur by chance association during drug treatment, particularly in patients predisposed to mood disorder. Single case reports are unreliable, and evidence must be sought from large series of treated patients, particularly those with a matched control group. Drugs with a definite propensity to cause manic symptoms include levodopa, corticosteroids and anabolic-androgenic steroids. Antidepressants of the tricyclic and monoamine oxidase inhibitor classes can induce mania in patients with pre-existing bipolar affective disorder. Drugs which are probably capable of inducing mania, but for which the evidence is less scientifically secure, include other dopaminergic anti-Parkinsonian drugs, thyroxine, iproniazid and isoniazid, sympathomimetic drugs, chloroquine, baclofen, alprazolam, captopril, amphetamine and phencyclidine. Other drugs may induce mania rarely and idiosyncratically. Management involves discontinuation or dosage reduction of the suspected drug, if this is medically possible, and treatment of manic symptoms with antipsychotic drugs or lithium.

  16. Crystalglobulin-induced nephropathy.

    PubMed

    Gupta, Vinay; El Ters, Mireille; Kashani, Kianoush; Leung, Nelson; Nasr, Samih H

    2015-03-01

    Crystalline nephropathy refers to renal parenchymal deposition of crystals leading to kidney damage. The most common forms of crystalline nephropathy encountered in renal pathology are nephrocalcinosis and oxalate nephropathy. Less frequent types include urate nephropathy, cystinosis, dihydroxyadeninuria, and drug-induced crystalline nephropathy (e.g., caused by indinavir or triamterene). Monoclonal proteins can also deposit in the kidney as crystals and cause tissue damage. This occurs in conditions such as light chain proximal tubulopathy, crystal-storing histiocytosis, and crystalglobulinemia. The latter is a rare complication of multiple myeloma that results from crystallization of monoclonal proteins in the systemic vasculature, leading to vascular injury, thrombosis, and occlusion. In this report, we describe a case of crystalglobulin-induced nephropathy and discuss its pathophysiology and the differential diagnosis of paraprotein-induced crystalline nephropathy.

  17. Geomagnetism and induced voltage

    NASA Astrophysics Data System (ADS)

    Abdul-Razzaq, W.; Biller, R. D.

    2010-07-01

    Introductory physics laboratories have seen an influx of conceptual integrated science over time in their classrooms with elements of other sciences such as chemistry, biology, Earth science, and astronomy. We describe a laboratory to introduce this development, as it attracts attention to the voltage induced in the human brain as it is initiated by the change in the magnetic flux due to the Earth's magnetic field and movement. This simple and enjoyable experiment will demonstrate how basic concepts in physics and geology can help us think about possible health effects due to the induced voltage.

  18. Surgery induced immunosuppression.

    PubMed

    Hogan, Brian V; Peter, Mark B; Shenoy, Hrishikesh G; Horgan, Kieran; Hughes, Thomas A

    2011-02-01

    Surgery and anaesthesia result in a variety of metabolic and endocrine responses, which result in a generalised state of immunosuppression in the immediate post-operative period. Surgery induced immunosuppression has been implicated in the development of post-operative septic complications and tumour metastasis formation. In addition the effectiveness of many treatments in the adjuvant setting is dependent on a functioning immune system. By understanding the mechanisms contributing to surgery-induced immunosuppression, surgeons may undertake strategies to minimise its effect and reduce potential short-term and long-term consequences to patients.

  19. Olmesartan-Induced Enteropathy

    PubMed Central

    Adike, Abimbola; Corral, Juan; Rybnicek, David; Sussman, Daniel; Shah, Samir; Quigley, Eamonn

    2016-01-01

    Olmesartan-induced enteropathy mimics celiac disease clinically and pathologically. As in celiac disease, the pathologic findings are villous atrophy and increased intraepithelial lymphocytes. Clinical presentation of olmesartan-induced enteropathy includes diarrhea, weight loss, and nausea. In contrast to celiac disease, tissue transglutaminase is not elevated and there is no response to a gluten-free diet. Including this entity in the differential diagnosis of sprue-like enteropathy is critical for its early diagnosis since replacing olmesartan with an alternative antihypertensive drug can simplify the diagnostic workup and provide both clinical and histologic improvement. PMID:28289500

  20. Injection-induced earthquakes.

    PubMed

    Ellsworth, William L

    2013-07-12

    Earthquakes in unusual locations have become an important topic of discussion in both North America and Europe, owing to the concern that industrial activity could cause damaging earthquakes. It has long been understood that earthquakes can be induced by impoundment of reservoirs, surface and underground mining, withdrawal of fluids and gas from the subsurface, and injection of fluids into underground formations. Injection-induced earthquakes have, in particular, become a focus of discussion as the application of hydraulic fracturing to tight shale formations is enabling the production of oil and gas from previously unproductive formations. Earthquakes can be induced as part of the process to stimulate the production from tight shale formations, or by disposal of wastewater associated with stimulation and production. Here, I review recent seismic activity that may be associated with industrial activity, with a focus on the disposal of wastewater by injection in deep wells; assess the scientific understanding of induced earthquakes; and discuss the key scientific challenges to be met for assessing this hazard.

  1. Shrouded inducer pump

    DOEpatents

    Meng, S.Y.

    1989-08-08

    An improvement in a pump is described including a shrouded inducer, the improvement comprising first and second sealing means which cooperate with a first vortex cell and a series of secondary vortex cells to remove any tangential velocity components from the recirculation flow. 3 figs.

  2. [Chemotherapy-induced alopecia].

    PubMed

    Spaëth, Dominique; Rosso, Nathalie; Clivot, Laetitia

    2006-11-30

    Chemotherapy-induced alopecia is frequent with most chemotherapy regimens; mechanisms, evolution and small prevention tools are described. Scalp cooling (helmets or continuous cooling systems) can avoid or diminish hair loss in selected chemotherapy regimens but tolerance can be fair and long harmlessness needs to be confirmed by prospective studies. Drug prevention is only in the first steps of research.

  3. Effects of Induced Astigmatism.

    ERIC Educational Resources Information Center

    Schubert, Delwyn G.; Walton, Howard N.

    1968-01-01

    The relationship of astigmatism to reading and the possible detrimental effects it might have on reading were investigated. The greatest incidence of astigmatism was for the with-the-rule type ranging from .50 to 1.00 diopter. This type of astigmatism was induced in 35 seniors from the Los Angeles College of Optometry by placing cylindrical lenses…

  4. Drug-induced uveitis

    PubMed Central

    2013-01-01

    A number of medications have been associated with uveitis. This review highlights both well-established and recently reported systemic, topical, intraocular, and vaccine-associated causes of drug-induced uveitis, and assigns a quantitative score to each medication based upon criteria originally described by Naranjo and associates. PMID:23522744

  5. Drug-induced hyperkalemia.

    PubMed

    Ben Salem, Chaker; Badreddine, Atef; Fathallah, Neila; Slim, Raoudha; Hmouda, Houssem

    2014-09-01

    Hyperkalemia is a common clinical condition that can be defined as a serum potassium concentration exceeding 5.0 mmol/L. Drug-induced hyperkalemia is the most important cause of increased potassium levels in everyday clinical practice. Drug-induced hyperkalemia may be asymptomatic. However, it may be dramatic and life threatening, posing diagnostic and management problems. A wide range of drugs can cause hyperkalemia by a variety of mechanisms. Drugs can interfere with potassium homoeostasis either by promoting transcellular potassium shift or by impairing renal potassium excretion. Drugs may also increase potassium supply. The reduction in renal potassium excretion due to inhibition of the renin-angiotensin-aldosterone system represents the most important mechanism by which drugs are known to cause hyperkalemia. Medications that alter transmembrane potassium movement include amino acids, beta-blockers, calcium channel blockers, suxamethonium, and mannitol. Drugs that impair renal potassium excretion are mainly represented by angiotensin-converting enzyme inhibitors, angiotensin-II receptor blockers, direct renin inhibitors, nonsteroidal anti-inflammatory drugs, calcineurin inhibitors, heparin and derivatives, aldosterone antagonists, potassium-sparing diuretics, trimethoprim, and pentamidine. Potassium-containing agents represent another group of medications causing hyperkalemia. Increased awareness of drugs that can induce hyperkalemia, and monitoring and prevention are key elements for reducing the number of hospital admissions, morbidity, and mortality related to drug-induced hyperkalemia.

  6. Injection-induced earthquakes

    USGS Publications Warehouse

    Ellsworth, William L.

    2013-01-01

    Earthquakes in unusual locations have become an important topic of discussion in both North America and Europe, owing to the concern that industrial activity could cause damaging earthquakes. It has long been understood that earthquakes can be induced by impoundment of reservoirs, surface and underground mining, withdrawal of fluids and gas from the subsurface, and injection of fluids into underground formations. Injection-induced earthquakes have, in particular, become a focus of discussion as the application of hydraulic fracturing to tight shale formations is enabling the production of oil and gas from previously unproductive formations. Earthquakes can be induced as part of the process to stimulate the production from tight shale formations, or by disposal of wastewater associated with stimulation and production. Here, I review recent seismic activity that may be associated with industrial activity, with a focus on the disposal of wastewater by injection in deep wells; assess the scientific understanding of induced earthquakes; and discuss the key scientific challenges to be met for assessing this hazard.

  7. Geomagnetism and Induced Voltage

    ERIC Educational Resources Information Center

    Abdul-Razzaq, W.; Biller, R. D.

    2010-01-01

    Introductory physics laboratories have seen an influx of "conceptual integrated science" over time in their classrooms with elements of other sciences such as chemistry, biology, Earth science, and astronomy. We describe a laboratory to introduce this development, as it attracts attention to the voltage induced in the human brain as it…

  8. Shrouded inducer pump

    SciTech Connect

    Meng, Sen Y.

    1989-01-01

    An improvement in a pump including a shrouded inducer, the improvement comprising first and second sealing means 32,36 which cooperate with a first vortex cell 38 and a series of secondary vortex cells 40 to remove any tangential velocity components from the recirculation flow.

  9. Statin-induced Myopathy.

    PubMed

    Fitzgerald, Kara; Redmond, Elizabeth; Harbor, Cathryn

    2012-05-01

    Heart disease (HD) is the number one killer in the United States.(1) In 2006, the direct and indirect costs associated with cardiovascular disease in the United States were estimated at 400 billion dollars.(2) Statin therapy for cholesterol reduction is a mainstay intervention for cardiovascular disease (CVD) as reflected in atorvastatin's status as the number one prescribed medication in the United States.(3) Statin therapy, however, is also associated with side effects that signal mitochondrial distress. A commonly reported statin-induced symptom is myalgia, which is defined as muscle pain without an associated elevation of serum creatine kinase (CK). In clinical trials, the reports of myalgia vary from less than 1% to 25% of patients.(4) Myopathy is a general term defined as an abnormal condition or disease of muscle tissue. Myopathy includes myalgia, myositis (inflammation of muscle tissue associated with elevated CK) and the very serious condition rhabdomyolysis (extreme myositis). Histological findings in statin-induced myopathy demonstrate electron chain dysfunction making "mitochondrial myopathy" the more precise term.(5) Mitochondrial myopathy has been associated with statin-induced CoQ10 depletion.(5) Given the density of mitochondria in cardiomyocytes, and CoQ10's role in mitochondrial energy production, depletion has long been associated with increased risk for heart disease.(6-7) In the case below, mitochondrial-specific organic acids, serum CoQ10, vitamin D and clinical history all suggest statin-induced mitochondrial myopathy, despite normal serum CK.

  10. Bacteriocin Inducer Peptides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Novel peptides produced by bacteriocin-producing bacteria stimulate the production of bacteriocins in vitro. The producer bacteria are cultured in the presence of a novel inducer bacteria and a peptide having a carboxy terminal sequence of VKGLT in order to achieve an increase in bacteriocin produc...

  11. Induced Angular Momentum

    ERIC Educational Resources Information Center

    Parker, G. W.

    1978-01-01

    Discusses, classically and quantum mechanically, the angular momentum induced in the bound motion of an electron by an external magnetic field. Calculates the current density and its magnetic moment, and then uses two methods to solve the first-order perturbation theory equation for the required eigenfunction. (Author/GA)

  12. Topological induced gravity

    NASA Astrophysics Data System (ADS)

    Oda, Ichiro

    We propose a topological model of induced gravity (pregeometry) where both Newton’s coupling constant and the cosmological constant appear as integration constants in solving field equations. The matter sector of a scalar field is also considered, and by solving field equations it is shown that various types of cosmological solutions in the Friedmann-Robertson-Walker (FRW) universe can be obtained. A detailed analysis is given of the meaning of the BRST transformations, which make the induced gravity be a topological field theory, by means of the canonical quantization analysis, and the physical reason why such BRST transformations are needed in the present formalism is clarified. Finally, we propose a dynamical mechanism for fixing the Lagrange multiplier fields by following the Higgs mechanism. The present study clearly indicates that the induced gravity can be constructed at the classical level without recourse to quantum fluctuations of matter and suggests an interesting relationship between the induced gravity and the topological quantum-field theory (TQFT).

  13. Schedule-Induced Stereotypy.

    ERIC Educational Resources Information Center

    Emerson, Eric; Howard, Denise

    1992-01-01

    The phenomena of the induction and entrainment of adjunctive behaviors was investigated in 8 people (ages 5-51) with severe or profound mental retardation who exhibited stereotypic behaviors. Seven of the eight demonstrated evidence of schedule-induced stereotypic behavior, whereas five also showed evidence of the entrainment of these behaviors by…

  14. Warfarin-induced erythroderma.

    PubMed

    Rowe, Casey J; Robertson, Ivan; James, Daniel; McMeniman, Erin

    2015-02-01

    Erythroderma is a potentially serious and life-threatening skin disease with a number of possible aetiologies. Drug reactions are well-documented causes, with carbamazepine, penicillin and allopurinol being the most commonly implicated. This case describes a unique presentation of warfarin-induced erythroderma in a 78-year-old female patient.

  15. Friction induced rail vibrations

    NASA Astrophysics Data System (ADS)

    Kralov, Ivan; Sinapov, Petko; Nedelchev, Krasimir; Ignatov, Ignat

    2012-11-01

    A model of rail, considered as multiple supported beam, subjected on friction induced vibration is studied in this work using FEM. The model is presented as continuous system and the mass and elastic properties of a real object are taken into account. The friction forces are nonlinear functions of the relative velocity during slipping. The problem is solved using Matlab Simulink.

  16. Heparin-induced thrombocytopaenia.

    PubMed

    Gounden, Ronald; Blockman, Marc

    2008-01-01

    Heparin-induced thrombocytopaenia (HIT) is an acquired, transient prothrombotic disorder caused by heparin. The predominant problem is the creation of a prothrombotic milieu, accompanied by a fall in the platelet count. This explains the apparent paradox of thrombosis in the face of thrombocytopaenia and why non-heparin antithrombotic agents are integral to its management.

  17. Viral induced demyelination.

    PubMed

    Stohlman, S A; Hinton, D R

    2001-01-01

    Viral induced demyelination, in both humans and rodent models, has provided unique insights into the cell biology of oligodendroglia, their complex cell-cell interactions and mechanisms of myelin destruction. They illustrate mechanisms of viral persistence, including latent infections in which no infectious virus is readily evident, virus reactivation and viral-induced tissue damage. These studies have also provided excellent paradigms to study the interactions between the immune system and the central nervous system (CNS). Although of interest in their own right, an understanding of the diverse mechanisms used by viruses to induce demyelination may shed light into the etiology and pathogenesis of the common demyelinating disorder multiple sclerosis (MS). This notion is supported by the persistent view that a viral infection acquired during adolescence might initiate MS after a long period of quiescence. Demyelination in both humans and rodents can be initiated by infection with a diverse group of enveloped and non-enveloped RNA and DNA viruses (Table 1). The mechanisms that ultimately result in the loss of CNS myelin appear to be equally diverse as the etiological agents capable of causing diseases which result in demyelination. Although demyelination can be a secondary result of axonal loss, in many examples of viral induced demyelination, myelin loss is primary and associated with axonal sparing. This suggests that demyelination induced by viral infections can result from: 1) a direct viral infection of oligodendroglia resulting in cell death with degeneration of myelin and its subsequent removal; 2) a persistent viral infection, in the presence or absence of infectious virus, resulting in the loss of normal cellular homeostasis and subsequent oligodendroglial death; 3) a vigorous virus-specific inflammatory response wherein the virus replicates in a cell type other than oligodendroglia, but cytokines and other immune mediators directly damage the

  18. [Steroid-induced osteoporosis].

    PubMed

    Perrot, Serge; Le Jeunne, Claire

    2012-04-01

    Bone-related steroid involvement is one of the most frequent complications of steroid treatment. Epidemiological data demonstrate that osteoporosis starts early during the treatment, predominantly involves trabecular bone and is correlated to dosage and treatment duration. Mechanisms and consequences of steroid bone involvement are related to osseous and extra-osseous mechanisms. In clinical practice, steroid-induced osteoporosis remains underdiagnosed and undertreated both in preventive and curative approaches. Recently, new molecules as teriparatide and zoledronic acid got indication for the treatment of steroid-induced osteoporosis. To guide treatment strategies, several recommendations are available: French, not updated recommendations since 2003 (Afssaps, 2003), European elaborated by the EULAR in 2007 and those of the ACR updated in 2010.

  19. Hypoxia-Inducible Hydrogels

    PubMed Central

    Park, Kyung Min; Gerecht, Sharon

    2014-01-01

    Oxygen is vital for the existence of all multicellular organisms, acting as a signaling molecule regulating cellular activities. Specifically, hypoxia, which occurs when the partial pressure of oxygen falls below 5%, plays a pivotal role during development, regeneration, and cancer. Here we report a novel hypoxia-inducible (HI) hydrogel composed of gelatin and ferulic acid that can form hydrogel networks via oxygen consumption in a laccase-mediated reaction. Oxygen levels and gradients within the hydrogels can be accurately controlled and precisely predicted. We demonstrate that HI hydrogels guide vascular morphogenesis in vitro via hypoxia-inducible factors activation of matrix metalloproteinases and promote rapid neovascularization from the host tissue during subcutaneous wound healing. The HI hydrogel is a new class of biomaterials that may prove useful in many applications, ranging from fundamental studies of developmental, regenerative and disease processes through the engineering of healthy and diseased tissue models towards the treatment of hypoxia-regulated disorders. PMID:24909742

  20. Current induced interlayer coupling

    NASA Astrophysics Data System (ADS)

    Levy, Peter M.; Heide, Carsten; Zhang, Shufeng; Fert, Albert

    2001-03-01

    It has recently been shown that a perpendicular current in a magnetically multilayered structures induces an unusual bilinear coupling between the magnetizations of the layers [1]. While this was demonstrated in the ballistic regime, transport is likely to be diffusive in the structures where this may be relevant to the role of currents in switching the magnetization of the layers. We have derived the current induced coupling by using the Boltzmann equation in terms of the parameters used to describe the giant magnetoresistance of magnetically layered structures, and thereby estimate the strength of this coupling. Work supported in part by DARPA and ONR. [1] C.Heide and R.J.Elliott, Europhys. Lett. 50, 271 (2000).

  1. Tulipalin A induced phytotoxicity.

    PubMed

    McCluskey, James; Bourgeois, Marie; Harbison, Raymond

    2014-04-01

    Tulipalin A induced phytotoxicity is a persistent allergic contact dermatitides documented in floral workers exposed to Alstroemeria and its cultivars.[1] The causative allergen is tulipalin A, a toxic glycoside named for the tulip bulbs from which it was first isolated.[2] The condition is characterized by fissured acropulpitis, often accompanied by hyperpigmentation, onychorrhexis, and paronychia. More of the volar surface may be affected in sensitized florists. Dermatitis and paronychia are extremely common conditions and diagnostic errors may occur. A thorough patient history, in conjunction with confirmatory patch testing with a bulb sliver and tuliposide A exposure, can prevent misdiagnosis. We report a case of Tulipalin A induced phytotoxicity misdiagnosed as an unresolved tinea manuum infection in a patient evaluated for occupational exposure.

  2. Tulipalin A induced phytotoxicity

    PubMed Central

    McCluskey, James; Bourgeois, Marie; Harbison, Raymond

    2014-01-01

    Tulipalin A induced phytotoxicity is a persistent allergic contact dermatitides documented in floral workers exposed to Alstroemeria and its cultivars.[1] The causative allergen is tulipalin A, a toxic glycoside named for the tulip bulbs from which it was first isolated.[2] The condition is characterized by fissured acropulpitis, often accompanied by hyperpigmentation, onychorrhexis, and paronychia. More of the volar surface may be affected in sensitized florists. Dermatitis and paronychia are extremely common conditions and diagnostic errors may occur. A thorough patient history, in conjunction with confirmatory patch testing with a bulb sliver and tuliposide A exposure, can prevent misdiagnosis. We report a case of Tulipalin A induced phytotoxicity misdiagnosed as an unresolved tinea manuum infection in a patient evaluated for occupational exposure. PMID:25024947

  3. Sepsis-induced Cardiomyopathy

    PubMed Central

    Romero-Bermejo, Francisco J; Ruiz-Bailen, Manuel; Gil-Cebrian, Julián; Huertos-Ranchal, María J

    2011-01-01

    Myocardial dysfunction is one of the main predictors of poor outcome in septic patients, with mortality rates next to 70%. During the sepsis-induced myocardial dysfunction, both ventricles can dilate and diminish its ejection fraction, having less response to fluid resuscitation and catecholamines, but typically is assumed to be reversible within 7-10 days. In the last 30 years, It´s being subject of substantial research; however no explanation of its etiopathogenesis or effective treatment have been proved yet. The aim of this manuscript is to review on the most relevant aspects of the sepsis-induced myocardial dysfunction, discuss its clinical presentation, pathophysiology, etiopathogenesis, diagnostic tools and therapeutic strategies proposed in recent years. PMID:22758615

  4. Buckling-Induced Kirigami

    NASA Astrophysics Data System (ADS)

    Rafsanjani, Ahmad; Bertoldi, Katia

    2017-02-01

    We investigate the mechanical response of thin sheets perforated with a square array of mutually orthogonal cuts, which leaves a network of squares connected by small ligaments. Our combined analytical, experimental and numerical results indicate that under uniaxial tension the ligaments buckle out of plane, inducing the formation of 3D patterns whose morphology is controlled by the load direction. We also find that by largely stretching the buckled perforated sheets, plastic strains develop in the ligaments. This gives rise to the formation of kirigami sheets comprising periodic distribution of cuts and permanent folds. As such, the proposed buckling-induced pop-up strategy points to a simple route for manufacturing complex morphable structures out of flat perforated sheets.

  5. Buckling-Induced Kirigami.

    PubMed

    Rafsanjani, Ahmad; Bertoldi, Katia

    2017-02-24

    We investigate the mechanical response of thin sheets perforated with a square array of mutually orthogonal cuts, which leaves a network of squares connected by small ligaments. Our combined analytical, experimental and numerical results indicate that under uniaxial tension the ligaments buckle out of plane, inducing the formation of 3D patterns whose morphology is controlled by the load direction. We also find that by largely stretching the buckled perforated sheets, plastic strains develop in the ligaments. This gives rise to the formation of kirigami sheets comprising periodic distribution of cuts and permanent folds. As such, the proposed buckling-induced pop-up strategy points to a simple route for manufacturing complex morphable structures out of flat perforated sheets.

  6. Cocaine-Induced Vasculitis

    PubMed Central

    Berman, Mark; Paran, Daphna; Elkayam, Ori

    2016-01-01

    The use of cocaine continues to grow worldwide. One of the possible side-effects of cocaine is vasculitis. Two distinct vasculitic syndromes have been described due to cocaine. One is cocaine-induced midline destructive lesion, secondary to a direct vasoconstrictor effect of cocaine, inducing ischemic necrosis of the septal cartilage and perforation of the nasal septum, mimicking findings of granulomatosis with polyangiitis in the upper airways. The other is ANCA-associated vasculitis, attributed to the levamisole component that contaminates about 70% of the cocaine. This type of vasculitis may be myeloperoxidase (MPO) and proteinase 3 (PR3) positive, and its main manifestations are typical cutaneous findings, arthralgia, otolaryngologic involvement, and agranulocytosis. A high degree of suspicion and awareness is needed in order properly to diagnose and treat these patients. PMID:27824551

  7. Drug-induced hypokalaemia.

    PubMed

    Ben Salem, Chaker; Hmouda, Houssem; Bouraoui, Kamel

    2009-01-01

    Hypokalaemia (defined as a plasma potassium concentration<3.5 mEq/L) is a common electrolyte abnormality in clinical practice. Drugs are a common cause of either asymptomatic or symptomatic hypokalaemia. Drug-induced hypokalaemia is an important problem particularly in the elderly and in patients with cardiovascular, renal or hepatic disease. Hypokalaemia can complicate the use of the drug in the therapeutic concentration range, and can also be precipitated with overdose or conditions leading to drug intoxication. Because the etiologies of hypokalaemia are numerous, the diagnosis of drug-induced hypokalaemia may be overlooked. Physicians should always pay close attention to this common side effect. Evaluation and management of a hypokalaemic patient should include a careful review of medications history to determine if a drug capable of causing or aggravating this electrolyte abnormality is present.

  8. Radiation-induced schwannomas

    SciTech Connect

    Rubinstein, A.B.; Reichenthal, E.; Borohov, H.

    1989-06-01

    The histopathology and clinical course of three patients with schwannomas of the brain and high cervical cord after therapeutic irradiation for intracranial malignancy and for ringworm of the scalp are described. Earlier reports in the literature indicated that radiation of the scalp may induce tumors in the head and neck. It is therefore suggested that therapeutic irradiation in these instances was a causative factor in the genesis of these tumors.

  9. Polarization induced doped transistor

    SciTech Connect

    Xing, Huili; Jena, Debdeep; Nomoto, Kazuki; Song, Bo; Zhu, Mingda; Hu, Zongyang

    2016-06-07

    A nitride-based field effect transistor (FET) comprises a compositionally graded and polarization induced doped p-layer underlying at least one gate contact and a compositionally graded and doped n-channel underlying a source contact. The n-channel is converted from the p-layer to the n-channel by ion implantation, a buffer underlies the doped p-layer and the n-channel, and a drain underlies the buffer.

  10. Drug-induced diarrhoea.

    PubMed

    Chassany, O; Michaux, A; Bergmann, J F

    2000-01-01

    Diarrhoea is a relatively frequent adverse event, accounting for about 7% of all drug adverse effects. More than 700 drugs have been implicated in causing diarrhoea; those most frequently involved are antimicrobials, laxatives, magnesium-containing antacids, lactose- or sorbitol-containing products, nonsteroidal anti-inflammatory drugs, prostaglandins, colchicine, antineoplastics, antiarrhythmic drugs and cholinergic agents. Certain new drugs are likely to induce diarrhoea because of their pharmacodynamic properties; examples include anthraquinone-related agents, alpha-glucosidase inhibitors, lipase inhibitors and cholinesterase inhibitors. Antimicrobials are responsible for 25% of drug-induced diarrhoea. The disease spectrum of antimicrobial-associated diarrhoea ranges from benign diarrhoea to pseudomembranous colitis. Several pathophysiological mechanisms are involved in drug-induced diarrhoea: osmotic diarrhoea, secretory diarrhoea, shortened transit time, exudative diarrhoea and protein-losing enteropathy, and malabsorption or maldigestion of fat and carbohydrates. Often 2 or more mechanisms are present simultaneously. In clinical practice, 2 major types of diarrhoea are seen: acute diarrhoea, which usually appears during the first few days of treatment, and chronic diarrhoea, lasting more than 3 or 4 weeks and which can appear a long time after the start of drug therapy. Both can be severe and poorly tolerated. In a patient presenting with diarrhoea, the medical history is very important, especially the drug history, as it can suggest a diagnosis of drug-induced diarrhoea and thereby avoid multiple diagnostic tests. The clinical examination should cover severity criteria such as fever, rectal emission of blood and mucus, dehydration and bodyweight loss. Establishing a relationship between drug consumption and diarrhoea or colitis can be difficult when the time elapsed between the start of the drug and the onset of symptoms is long, sometimes up to several

  11. Arsenic-Induced Pancreatitis

    PubMed Central

    Connelly, Sean; Zancosky, Krysia; Farah, Katie

    2011-01-01

    The introduction of all-trans retinoic acid (ATRA) and arsenic trioxide has brought about tremendous advancement in the treatment of acute promyelocytic myelogenous leukemia (APML). In most instances, the benefits of these treatments outweigh the risks associated with their respective safety profiles. Although acute pancreatitis is not commonly associated with arsenic toxicity, it should be considered as a possible side effect. We report a case of arsenic-induced pancreatitis in a patient with APML. PMID:22606427

  12. Ketamine-Induced Hallucinations

    PubMed Central

    Powers, A.R.; Gancsos, M.G.; Finn, E.S.; Morgan, P.T.; Corlett, P.R.

    2015-01-01

    Background Ketamine, the NMDA glutamate receptor antagonist drug, is increasingly employed as an experimental model of psychosis in healthy volunteers. At sub-anesthetic doses, it safely and reversibly causes delusion-like ideas, amotivation, and perceptual disruptions reminiscent of the aberrant salience experiences that characterize first-episode psychosis. However, auditory verbal hallucinations (AVHs), a hallmark symptom of schizophrenia, have not been reported consistently in healthy volunteers even at high doses of ketamine. Methods Here we present data from a set of healthy participants who received moderately dosed, placebo controlled ketamine infusions in the reduced stimulation environment of the magnetic resonance imaging scanner. We highlight the phenomenological experiences of three participants who experienced particularly vivid hallucinations. Results Participants in this series reported auditory verbal and musical hallucinations at a ketamine dose that does not induce auditory hallucination outside of the scanner. Discussion We interpret the observation of ketamine-induced AVHs in the context of the reduced perceptual environment of the magnetic resonance scanner, and offer an explanation grounded in predictive coding models of perception and psychosis: the brain fills in expected perceptual inputs and it does so more in situations of reduced perceptual input. The reduced perceptual input of the MRI scanner creates a mismatch between top-down perceptual expectations and the heightened bottom-up signals induced by ketamine; such circumstances induce aberrant percepts including musical and auditory verbal hallucinations. We suggest that these circumstances might represent a useful experimental model of AVHs and highlight the impact of ambient sensory stimuli on psychopathology. PMID:26361209

  13. Allopurinol induced erythroderma.

    PubMed

    Sharma, Geeta; Govil, Dinesh Chandra

    2013-01-01

    Allopurinol, a widely prescribed urate lowering agent is responsible for various adverse drug reactions, including erythroderma. A 45-year-old male patient was admitted with the complaints of fever, redness and scaling all over the body after 3-4 weeks of allopurinol treatment for asymptomatic hyperuricemia. Elevated liver enzymes were detected in his blood analysis. Skin biopsy was consistent with drug induced erythroderma. Allopurinol was stopped and steroids were started. Patient improved over a period of 2 weeks.

  14. Allergen-induced asthma

    PubMed Central

    Cockcroft, Donald W

    2014-01-01

    It was only in the late 19th century that specific allergens, pollen, animal antigens and, later, house dust mite, were identified to cause upper and lower airway disease. Early allergen challenge studies, crudely monitored before measurement of forced expiratory volume in 1 s became widespread in the 1950s, focused on the immediate effects but noted in passing prolonged and/or recurrent asthma symptoms. The late asthmatic response, recurrent bronchoconstriction after spontaneous resolution of the early responses occurring 3 h to 8 h or more postchallenge, has been identified and well characterized over the past 50 years. The associated allergen-induced airway hyper-responsiveness (1977) and allergen-induced airway inflammation (1985) indicate that these late sequelae are important in the mechanism of allergen-induced asthma. Allergens are now recognized to be the most important cause of asthma. A standardized allergen inhalation challenge model has been developed and is proving to be a valuable research tool in the investigation of asthma pathophysiology and of potential new pharmacological agents for the treatment of asthma. PMID:24791256

  15. Glycerol-induced hyperhydration

    NASA Technical Reports Server (NTRS)

    Riedesel, Marvin L.; Lyons, Timothy P.; Mcnamara, M. Colleen

    1991-01-01

    Maintenance of euhydration is essential for maximum work performance. Environments which induce hypohydration reduce plasma volume and cardiovascular performance progressively declines as does work capacity. Hyperhydration prior to exposure to dehydrating environments appears to be a potential countermeasure to the debilitating effects of hypohydration. The extravascular fluid space, being the largest fluid compartment in the body, is the most logical space by which significant hyperhydration can be accomplished. Volume and osmotic receptors in the vascular space result in physiological responses which counteract hyperhydration. Our hypothesis is that glycerol-induced hyperhydration (GIH) can accomplish extravascular fluid expansion because of the high solubility of glycerol in lipid and aqueous media. A hypertonic solution of glycerol is rapidly absorbed from the gastrointestinal tract, results in mild increases in plasma osmolality and is distributed to 65 percent of the body mass. A large volume of water ingested within minutes after glycerol intake results in increased total body water because of the osmotic action and distribution of glycerol. The resulting expanded extravascular fluid space can act as a reservoir to maintain plasma volume during exposure to dehydrating environments. The fluid shifts associated with exposure to microgravity result in increased urine production and is another example of an environment which induces hypohydration. Our goal is to demonstrate that GIH will facilitate maintenance of euhydration and cardiovascular performance during space flight and upon return to a 1 g environment.

  16. Induced QCD I: theory

    NASA Astrophysics Data System (ADS)

    Brandt, Bastian B.; Lohmayer, Robert; Wettig, Tilo

    2016-11-01

    We explore an alternative discretization of continuum SU( N c ) Yang-Mills theory on a Euclidean spacetime lattice, originally introduced by Budzcies and Zirnbauer. In this discretization the self-interactions of the gauge field are induced by a path integral over N b auxiliary boson fields, which are coupled linearly to the gauge field. The main progress compared to earlier approaches is that N b can be as small as N c . In the present paper we (i) extend the proof that the continuum limit of the new discretization reproduces Yang-Mills theory in two dimensions from gauge group U( N c ) to SU( N c ), (ii) derive refined bounds on N b for non-integer values, and (iii) perform a perturbative calculation to match the bare parameter of the induced gauge theory to the standard lattice coupling. In follow-up papers we will present numerical evidence in support of the conjecture that the induced gauge theory reproduces Yang-Mills theory also in three and four dimensions, and explore the possibility to integrate out the gauge fields to arrive at a dual formulation of lattice QCD.

  17. Ethanol-induced analgesia

    SciTech Connect

    Pohorecky, L.A.; Shah, P.

    1987-09-07

    The effect of ethanol (ET) on nociceptive sensitivity was evaluated using a new tail deflection response (TDR) method. The IP injection of ET (0.5 - 1.5 g/kg) produced raid dose-dependent analgesia. Near maximal effect (97% decrease in TDR) was produced with the 1.5 g/kg dose of ET ten minutes after injection. At ninety minutes post-injection there was still significant analgesia. Depression of ET-induced nociceptive sensitivity was partially reversed by a 1 mg/kg dose of naloxone. On the other hand, morphine (0.5 or 5.0 mg/kg IP) did not modify ET-induced analgesia, while 3.0 minutes of cold water swim (known to produce non-opioid mediated analgesia) potentiated ET-induced analgesic effect. The 0.5 g/kg dose of ET by itself did not depress motor activity in an open field test, but prevented partially the depression in motor activity produced by cold water swim (CWS). Thus, the potentiation by ET of the depression of the TDR produced by CWS cannot be ascribed to the depressant effects of ET on motor activity. 21 references, 4 figures, 1 table.

  18. Study of cavitating inducer instabilities

    NASA Technical Reports Server (NTRS)

    Young, W. E.; Murphy, R.; Reddecliff, J. M.

    1972-01-01

    An analytic and experimental investigation into the causes and mechanisms of cavitating inducer instabilities was conducted. Hydrofoil cascade tests were performed, during which cavity sizes were measured. The measured data were used, along with inducer data and potential flow predictions, to refine an analysis for the prediction of inducer blade suction surface cavitation cavity volume. Cavity volume predictions were incorporated into a linearized system model, and instability predictions for an inducer water test loop were generated. Inducer tests were conducted and instability predictions correlated favorably with measured instability data.

  19. Radiation Induced Genomic Instability

    SciTech Connect

    Morgan, William F.

    2011-03-01

    Radiation induced genomic instability can be observed in the progeny of irradiated cells multiple generations after irradiation of parental cells. The phenotype is well established both in vivo (Morgan 2003) and in vitro (Morgan 2003), and may be critical in radiation carcinogenesis (Little 2000, Huang et al. 2003). Instability can be induced by both the deposition of energy in irradiated cells as well as by signals transmitted by irradiated (targeted) cells to non-irradiated (non-targeted) cells (Kadhim et al. 1992, Lorimore et al. 1998). Thus both targeted and non-targeted cells can pass on the legacy of radiation to their progeny. However the radiation induced events and cellular processes that respond to both targeted and non-targeted radiation effects that lead to the unstable phenotype remain elusive. The cell system we have used to study radiation induced genomic instability utilizes human hamster GM10115 cells. These cells have a single copy of human chromosome 4 in a background of hamster chromosomes. Instability is evaluated in the clonal progeny of irradiated cells and a clone is considered unstable if it contains three or more metaphase sub-populations involving unique rearrangements of the human chromosome (Marder and Morgan 1993). Many of these unstable clones have been maintained in culture for many years and have been extensively characterized. As initially described by Clutton et al., (Clutton et al. 1996) many of our unstable clones exhibit persistently elevated levels of reactive oxygen species (Limoli et al. 2003), which appear to be due dysfunctional mitochondria (Kim et al. 2006, Kim et al. 2006). Interestingly, but perhaps not surprisingly, our unstable clones do not demonstrate a “mutator phenotype” (Limoli et al. 1997), but they do continue to rearrange their genomes for many years. The limiting factor with this system is the target – the human chromosome. While some clones demonstrate amplification of this chromosome and thus lend

  20. Polycation induced actin bundles.

    PubMed

    Muhlrad, Andras; Grintsevich, Elena E; Reisler, Emil

    2011-04-01

    Three polycations, polylysine, the polyamine spermine and the polycationic protein lysozyme were used to study the formation, structure, ionic strength sensitivity and dissociation of polycation-induced actin bundles. Bundles form fast, simultaneously with the polymerization of MgATP-G-actins, upon the addition of polycations to solutions of actins at low ionic strength conditions. This indicates that nuclei and/or nascent filaments bundle due to attractive, electrostatic effect of polycations and the neutralization of repulsive interactions of negative charges on actin. The attractive forces between the filaments are strong, as shown by the low (in nanomolar range) critical concentration of their bundling at low ionic strength. These bundles are sensitive to ionic strength and disassemble partially in 100 mM NaCl, but both the dissociation and ionic strength sensitivity can be countered by higher polycation concentrations. Cys374 residues of actin monomers residing on neighboring filaments in the bundles can be cross-linked by the short span (5.4Å) MTS-1 (1,1-methanedyl bismethanethiosulfonate) cross-linker, which indicates a tight packing of filaments in the bundles. The interfilament cross-links, which connect monomers located on oppositely oriented filaments, prevent disassembly of bundles at high ionic strength. Cofilin and the polysaccharide polyanion heparin disassemble lysozyme induced actin bundles more effectively than the polylysine-induced bundles. The actin-lysozyme bundles are pathologically significant as both proteins are found in the pulmonary airways of cystic fibrosis patients. Their bundles contribute to the formation of viscous mucus, which is the main cause of breathing difficulties and eventual death in this disorder.

  1. Method for inducing hypothermia

    DOEpatents

    Becker, Lance B.; Hoek, Terry Vanden; Kasza, Kenneth E.

    2003-04-15

    Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

  2. Method for inducing hypothermia

    DOEpatents

    Becker, Lance B.; Hoek, Terry Vanden; Kasza, Kenneth E.

    2005-11-08

    Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

  3. Isoniazid-induced pellagra.

    PubMed

    Bilgili, Serap Gunes; Karadag, Ayse Serap; Calka, Omer; Altun, Faruk

    2011-12-01

    Pellagra is characterized by dermatitis, diarrhea, dementia and eventually death occurring as a result of niacin or its precursor tryptophan deficiency. Although pellagra is a well-known complication of isoniazid (INH) therapy, the clinical diagnosis may be missed or delayed that may cause life-threatening consequences. Due to the diversity of pellagra-related signs and symptoms, the diagnosis can be made with an appropriate index of suspicion. We report a 7-year-old boy presenting with INH-induced pellagra that resolved after the administration of the niacin therapy.

  4. Trastuzumab-induced cardiomyopathy.

    PubMed

    Guglin, Maya; Cutro, Raymond; Mishkin, Joseph D

    2008-06-01

    Trastuzumab is a recombinant humanized monoclonal antibody used for the treatment of advanced breast cancer. It improves survival and increases response to chemotherapy. The major side effect of trastuzumab is cardiotoxicity manifesting as a reduction in left ventricular systolic function, either asymptomatic or with signs and symptoms of heart failure. Although reversible in most cases, cardiotoxicity frequently results in the discontinuation of trastuzumab. The objective of this review is to summarize facts about trastuzumab-induced cardiotoxicity and to highlight the areas of future investigations. We searched PubMed for trials involving trastuzumab used as an adjuvant therapy for breast cancer, including the metastatic breast cancer setting, and focused on cardiotoxicity.

  5. Bupropion-induced somnambulism.

    PubMed

    Khazaal, Yasser; Krenz, Sonia; Zullino, Daniele Fabio

    2003-09-01

    Whereas there are some case reports of bupropion-induced vivid dreaming and nightmares, until now it has not been associated with somnambulism. A case is reported of a patient treated with bupropion as a smoking cessation medication, who developed somnambulism during nicotine withdrawal. Furthermore, the sleepwalking episodes were associated with eating behaviour. Amnesia was reported for all episodes. As, on one hand,bupropion is a noradrenergic and dopaminergic drug and nicotine withdrawal, on the other hand, is associated with alterations in monoaminergic functions, an interaction at the level of these neurotransmitters is suggested as the underlying mechanism.

  6. [Neuroleptic induced deficit syndrome].

    PubMed

    Szafrański, T

    1995-01-01

    Increasing interest in subjective aspects of therapy and rehabilitation focused the attention of psychiatrists, psychologists and psychopharmacologists on the mental side effects of neuroleptics. For the drug-related impairment of affective, cognitive and social function the name of neuroleptic-induced deficit syndrome (NIDS) is proposed. Patients with NIDS appear to be indifferent to the environmental stimuli, retarded and apathetic. They complain of feeling drugged and drowsy, weird, they suffer from lack of motivation, feel like "zombies". The paper presents description of NIDS and its differentiation from negative and depressive symptoms in schizophrenia and subjective perceiving of extrapyramidal syndromes.

  7. Drug-induced gynecomastia.

    PubMed

    Eckman, Ari; Dobs, Adrian

    2008-11-01

    Gynecomastia is caused by drugs in 10 - 25% of all cases. The pathophysiologic mechanism for some drugs includes exogenous estrogens exposure, medications that cause hypogonadism, anti-androgenic effects and hyperprolactinemia. This manuscript reviews common examples of drug-induced gynecomastia, discussing the mechanisms and possible treatments. Discontinuing the medication is always the best choice; however, if this is not possible, then testosterone replacement therapy may be needed for hypogonadism. When a man is euogonadal, a trial of the anti-estrogen, tamoxifen or an aromatase inhibitor may be an option.

  8. Inducing Pluripotency in Cattle.

    PubMed

    Malaver-Ortega, Luis F; Taheri-Ghahfarokhi, Amir; Sumer, Huseyin

    2015-01-01

    Nuclear reprogramming technologies in general and induced pluripotent stem cells (iPSCs) in particular have opened the door to a vast number of practical applications in regenerative medicine and biotechnology. It also represents a possible alternative to the still evasive achievement of embryonic stem cells (ESCs) isolation from refractory species such as Bos. taurus. Herein, we described a protocol for bovine iPSCs (biPSCs) generation and characterization. The protocol is based on the overexpression of the exogenous transcription factors NANOG, OCT4, SOX2, KLF4 and c-MYC, using a pantropic retroviral system.

  9. 5-fluorouracil induced pericarditis.

    PubMed

    Killu, Ammar; Madhavan, Malini; Prasad, Kavita; Prasad, Abhiram

    2011-04-15

    Cardiac toxicity is an infrequent, but potentially serious side effect of 5-fluorouracil (5-FU). The reported incidence of 5-FU-induced cardiotoxicity is approximately 3%, although estimates vary from 1.2% to 18%. Cardiac death occurs in less than 1%. The prompt recognition of cardiac toxicity demands a thorough understanding of the myriad of potential cardiac manifestations and a high index of suspicion. The most common presentation is angina pectoris while other manifestations, namely myocardial infarction, left ventricular dysfunction, arrhythmias and sudden death have been recognised. The authors report an unusual case of myopericarditis masquerading as myocardial infarction.

  10. Method for inducing hypothermia

    SciTech Connect

    Becker, Lance B.; Hoek, Terry Vanden; Kasza, Kenneth E.

    2008-09-09

    Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

  11. Antacid-induced osteomalacia.

    PubMed

    Boutsen, Y; Devogelaer, J P; Malghem, J; Noel, H; Nagant de Deuxchaisnes, C

    1996-01-01

    The case of a 49-year-old woman suffering from generalized skeletal pain and multiple fractures accompanied by severe hypophosphataemia and low urinary phosphorus excretion is reported. She had been taking large amounts of antacids containing aluminum hydroxide for many years. A diagnosis of antacid-induced osteomalacia was made. It was confirmed by biological work-up, radiographs and bone biopsy. A dramatic biological, osteodensitometric, and clinical improvement was achieved by withdrawal of antacids and phosphorus administration. The literature concerning this unusual condition has been reviewed.

  12. Drug-induced lupus.

    PubMed

    Rubin, Robert L

    2005-04-15

    Autoantibodies and, less commonly, systemic rheumatic symptoms are associated with treatment with numerous medications and other types of ingested compounds. Distinct syndromes can be distinguished, based on clinical and laboratory features, as well as exposure history. Drug-induced lupus has been reported as a side-effect of long-term therapy with over 40 medications. Its clinical and laboratory features are similar to systemic lupus erythematosus, except that patients fully recover after the offending medication is discontinued. This syndrome differs from typical drug hypersensitivity reactions in that drug-specific T-cells or antibodies are not involved in induction of autoimmunity, it usually requires many months to years of drug exposure, is drug dose-dependent and generally does not result in immune sensitization to the drug. Circumstantial evidence strongly suggests that oxidative metabolites of the parent compound trigger autoimmunity. Several mechanisms for induction of autoimmunity will be discussed, including bystander activation of autoreactive lymphocytes due to drug-specific immunity or to non-specific activation of lymphocytes, direct cytotoxicity with release of autoantigens and disruption of central T-cell tolerance. The latter hypothesis will be supported by a mouse model in which a reactive metabolite of procainamide introduced into the thymus results in lupus-like autoantibody induction. These findings, as well as evidence for thymic function in drug-induced lupus patients, support the concept that abnormalities during T-cell selection in the thymus initiate autoimmunity.

  13. [Exercise-induced anaphylaxis].

    PubMed

    Gani, Federica; Selvaggi, Lucia; Roagna, Davide

    2008-01-01

    Exercise-induced anaphylaxis (EIA) was defined for the first time in 1980. EIA is associated with different kind of exercise, although jogging is the most frequently reported. The clinical manifestations progress from itching, erythema and urticaria to some combination of cutaneous angioedema, gastrointestinal and laryngeal symptoms and signs of angioedema and vascular collapse. Mast cell participation in the pathogenesis of this syndrome has been proved by the finding of an elevated serum histamine level during experimentally-induced attacks and by cutaneous degranulation of mast cells with elevated serum tryptase after attacks. As predisposing factors of EIA, a specific or even aspecific sensitivity to food has been reported and such cases are called "food-dependent EIA". Many foods are implicated but particularly wheat, vegetables, crustacean. Another precipitating factor includes drugs intake (non steroidal anti-inflammatory drugs), climate variations and menstrual cycle factors. Treatment of an attack should include all the manoeuvres efficacious in the management of conventional anaphylactic syndrome, including the administration of epinephrine and antihistamines. Prevention of the attacks may be achieved with the interruption of the exercise at the appearance of the first premonitory symptoms. To prevent the onset of EIA it is also suitable to delay the exercise practice after at least 4-6 hours from the swallowing of food.

  14. Interferon induced thyroiditis.

    PubMed

    Tomer, Yaron; Menconi, Francesca

    2009-12-01

    Interferon-alpha (IFNalpha) is used for the treatment of various disorders, most notable chronic hepatitis C virus (HCV) infection. One of the commonest side effects of IFNalpha therapy is thyroiditis, with up to 40% of HCV patients on IFNalpha developing clinical or subclinical disease. In some cases interferon induced thyroiditis (IIT) may result in severe symptomatology necessitating discontinuation of therapy. IIT can manifest as clinical autoimmune thyroiditis, presenting with symptoms of classical Hashimoto's thyroiditis or Graves' disease, or as non-autoimmune thyroiditis. Non-autoimmune thyroiditis can manifest as destructive thyroiditis, with early thyrotoxicosis and later hypothyroidism, or as non-autoimmune hypothyroidism. While the epidemiology and clinical presentation of IIT have been well characterized the mechanisms causing IIT are still poorly understood. It is likely that the hepatitis C virus (HCV) itself plays a role in the disease, as the association between HCV infection and thyroiditis is well established. It is believed that IFNalpha induces thyroiditis by both immune stimulatory effects and by direct effects on the thyroid. Early detection and therapy of this condition are important in order to avoid complications of thyroid disease such as cardiac arrhythmias.

  15. [Gluten induced diseases].

    PubMed

    Frič, P; Zavoral, M; Dvořáková, T

    2013-05-01

    The introduction of cereals in human nutrition 10 000 years ago caused the occurrence of gluten induced diseases. This protein complex is involved in pathogenesis of wheat allergy, celiac disease, and gluten sensitivity. Wheat allergy and celiac disease are mediated by the system of adaptive immunity. Gluten sensitivity is a recently defined entity induced by innate immune mechanisms. These subjects present various intestinal and particularly extraintestinal symptoms. The differences between celiac disease and gluten intolerance include permeability of the intestinal mucosal barrier, histology of duodenal biopsy, and mucosal gene expression. The symptoms of gluten sensitivity may also have another genetic background of food intolerance independent of the HLADQ2, - DQ8 system and tissue transglutaminase (eg. in some psychiatric disorders). At present, there is no specific bio-marker of gluten sensitivity. The diagnosis is possible only by exclusion of other causes of symptoms and improvement on a glutenfree diet applied in a doubleblind placebo controlled manner with optional sequence of both stages to exclude the placebo effect due to nutritional intervention.

  16. Cholesterol depletion induces autophagy

    SciTech Connect

    Cheng, Jinglei; Ohsaki, Yuki; Tauchi-Sato, Kumi; Fujita, Akikazu; Fujimoto, Toyoshi . E-mail: tfujimot@med.nagoya-u.ac.jp

    2006-12-08

    Autophagy is a mechanism to digest cells' own components, and its importance in many physiological and pathological processes is being recognized. But the molecular mechanism that regulates autophagy is not understood in detail. In the present study, we found that cholesterol depletion induces macroautophagy. The cellular cholesterol in human fibroblasts was depleted either acutely using 5 mM methyl-{beta}-cyclodextrin or 10-20 {mu}g/ml nystatin for 1 h, or metabolically by 20 {mu}M mevastatin and 200 {mu}M mevalonolactone along with 10% lipoprotein-deficient serum for 2-3 days. By any of these protocols, marked increase of LC3-II was detected by immunoblotting and by immunofluorescence microscopy, and the increase was more extensive than that caused by amino acid starvation, i.e., incubation in Hanks' solution for several hours. The induction of autophagic vacuoles by cholesterol depletion was also observed in other cell types, and the LC3-positive membranes were often seen as long tubules, >50 {mu}m in length. The increase of LC3-II by methyl-{beta}-cyclodextrin was suppressed by phosphatidylinositol 3-kinase inhibitors and was accompanied by dephosphorylation of mammalian target of rapamycin. By electron microscopy, autophagic vacuoles induced by cholesterol depletion were indistinguishable from those seen after amino acid starvation. These results demonstrate that a decrease in cholesterol activates autophagy by a phosphatidylinositol 3-kinase-dependent mechanism.

  17. Statin-induced myopathies.

    PubMed

    Tomaszewski, Michał; Stępień, Karolina M; Tomaszewska, Joanna; Czuczwar, Stanisław J

    2011-01-01

    Statins are considered to be safe, well tolerated and the most efficient drugs for the treatment of hypercholesterolemia, one of the main risk factor for atherosclerosis, and therefore they are frequently prescribed medications. The most severe adverse effect of statins is myotoxicity, in the form of myopathy, myalgia, myositis or rhabdomyolysis. Clinical trials commonly define statin toxicity as myalgia or muscle weakness with creatine kinase (CK) levels greater than 10 times the normal upper limit. Rhabdomyolysis is the most severe adverse effect of statins, which may result in acute renal failure, disseminated intravascular coagulation and death. The exact pathophysiology of statin-induced myopathy is not fully known. Multiple pathophysiological mechanisms may contribute to statin myotoxicity. This review focuses on a number of them. The prevention of statin-related myopathy involves using the lowest statin dose required to achieve therapeutic goals and avoiding polytherapy with drugs known to increase systemic exposure and myopathy risk. Currently, the only effective treatment of statin-induced myopathy is the discontinuation of statin use in patients affected by muscle aches, pains and elevated CK levels.

  18. Drug-induced exanthems.

    PubMed

    Yawalkar, Nikhil

    2005-04-15

    Cutaneous adverse reactions to drugs can comprise a broad spectrum of clinical and histopathological features. Recent evidence from immunohistological and functional studies of drug-reactive T cells suggest that distinct T-cell functions may be responsible for this broad spectrum of different clinical reactions. Maculopapular exanthems represent the most commonly encountered cutaneous drug eruption. Previous studies on maculopapular exanthems indicate that drug-specific CD4+ T cells expressing cytotoxic granule proteins such as perforin and granzyme B are critically involved in killing activated keratinocytes. These cells are particularly found at the dermo-epidermal junction and may contribute to the generation of vacuolar alteration and destruction of basal keratinocytes, which are typical found in drug-induced maculopapular exanthems. In contrast to maculopapular exanthems, the preferential activation of drug-specific cytotoxic CD8+ T cells may lead to more severe reactions like bullous drug eruptions. Furthermore, activation of drug-specific T with distinct cytokine and chemokines profiles may also explain the different clinical features of drug-induced exanthems. IL-5 and eotaxin are upregulated in maculopapular exanthems and explain the eosinophilia often found in these reactions.

  19. Induced Seismicity Monitoring System

    NASA Astrophysics Data System (ADS)

    Taylor, S. R.; Jarpe, S.; Harben, P.

    2014-12-01

    There are many seismological aspects associated with monitoring of permanent storage of carbon dioxide (CO2) in geologic formations. Many of these include monitoring underground gas migration through detailed tomographic studies of rock properties, integrity of the cap rock and micro seismicity with time. These types of studies require expensive deployments of surface and borehole sensors in the vicinity of the CO2 injection wells. Another problem that may exist in CO2 sequestration fields is the potential for damaging induced seismicity associated with fluid injection into the geologic reservoir. Seismic hazard monitoring in CO2 sequestration fields requires a seismic network over a spatially larger region possibly having stations in remote settings. Expensive observatory-grade seismic systems are not necessary for seismic hazard deployments or small-scale tomographic studies. Hazard monitoring requires accurate location of induced seismicity to magnitude levels only slightly less than that which can be felt at the surface (e.g. magnitude 1), and the frequencies of interest for tomographic analysis are ~1 Hz and greater. We have developed a seismo/acoustic smart sensor system that can achieve the goals necessary for induced seismicity monitoring in CO2 sequestration fields. The unit is inexpensive, lightweight, easy to deploy, can operate remotely under harsh conditions and features 9 channels of recording (currently 3C 4.5 Hz geophone, MEMS accelerometer and microphone). An on-board processor allows for satellite transmission of parameter data to a processing center. Continuous or event-detected data is kept on two removable flash SD cards of up to 64+ Gbytes each. If available, data can be transmitted via cell phone modem or picked up via site visits. Low-power consumption allows for autonomous operation using only a 10 watt solar panel and a gel-cell battery. The system has been successfully tested for long-term (> 6 months) remote operations over a wide range

  20. Peripherally induced oromandibular dystonia

    PubMed Central

    Sankhla, C.; Lai, E.; Jankovic, J.

    1998-01-01

    OBJECTIVES—Oromandibular dystonia (OMD) is a focal dystonia manifested by involuntary muscle contractions producing repetitive, patterned mouth, jaw, and tongue movements. Dystonia is usually idiopathic (primary), but in some cases it follows peripheral injury. Peripherally induced cervical and limb dystonia is well recognised, and the aim of this study was to characterise peripherally induced OMD.
METHODS—The following inclusion criteria were used for peripherally induced OMD: (1) the onset of the dystonia was within a few days or months (up to 1 year) after the injury; (2) the trauma was well documented by the patient's history or a review of their medical and dental records; and (3) the onset of dystonia was anatomically related to the site of injury (facial and oral).
RESULTS—Twenty seven patients were identified in the database with OMD, temporally and anatomically related to prior injury or surgery. No additional precipitant other than trauma could be detected. None of the patients had any litigation pending. The mean age at onset was 50.11 (SD 14.15) (range 23-74) years and there was a 2:1 female preponderance. Mean latency between the initial trauma and the onset of OMD was 65 days (range 1 day-1 year). Ten (37%) patients had some evidence of predisposing factors such as family history of movement disorders, prior exposure to neuroleptic drugs, and associated dystonia affecting other regions or essential tremor. When compared with 21 patients with primary OMD, there was no difference for age at onset, female preponderance, and phenomenology. The frequency of dystonic writer's cramp, spasmodic dysphonia, bruxism, essential tremor, and family history of movement disorder, however, was lower in the post-traumatic group (p<0.05). In both groups the response to botulinum toxin treatment was superior to medical therapy (p<0.005). Surgical intervention for temporomandibular disorders was more frequent in the post-traumatic group and was associated with

  1. Drug-Induced Hematologic Syndromes

    PubMed Central

    Mintzer, David M.; Billet, Shira N.; Chmielewski, Lauren

    2009-01-01

    Objective. Drugs can induce almost the entire spectrum of hematologic disorders, affecting white cells, red cells, platelets, and the coagulation system. This paper aims to emphasize the broad range of drug-induced hematological syndromes and to highlight some of the newer drugs and syndromes. Methods. Medline literature on drug-induced hematologic syndromes was reviewed. Most reports and reviews focus on individual drugs or cytopenias. Results. Drug-induced syndromes include hemolytic anemias, methemoglobinemia, red cell aplasia, sideroblastic anemia, megaloblastic anemia, polycythemia, aplastic anemia, leukocytosis, neutropenia, eosinophilia, immune thrombocytopenia, microangiopathic syndromes, hypercoagulability, hypoprothrombinemia, circulating anticoagulants, myelodysplasia, and acute leukemia. Some of the classic drugs known to cause hematologic abnormalities have been replaced by newer drugs, including biologics, accompanied by their own syndromes and unintended side effects. Conclusions. Drugs can induce toxicities spanning many hematologic syndromes, mediated by a variety of mechanisms. Physicians need to be alert to the potential for iatrogenic drug-induced hematologic complications. PMID:19960059

  2. Induced seismicity. Final report

    SciTech Connect

    Segall, P.

    1997-09-18

    The objective of this project has been to develop a fundamental understanding of seismicity associated with energy production. Earthquakes are known to be associated with oil, gas, and geothermal energy production. The intent is to develop physical models that predict when seismicity is likely to occur, and to determine to what extent these earthquakes can be used to infer conditions within energy reservoirs. Early work focused on earthquakes induced by oil and gas extraction. Just completed research has addressed earthquakes within geothermal fields, such as The Geysers in northern California, as well as the interactions of dilatancy, friction, and shear heating, on the generation of earthquakes. The former has involved modeling thermo- and poro-elastic effects of geothermal production and water injection. Global Positioning System (GPS) receivers are used to measure deformation associated with geothermal activity, and these measurements along with seismic data are used to test and constrain thermo-mechanical models.

  3. [Tachycardia-induced cardiomyopathy].

    PubMed

    Povolný, Jan

    2015-01-01

    Cardiomyopathy is a heterogeneous group of diseases of heart muscle accompanied with impaired cardiac function. Tachycardia-induced cardiomyopathy (TIC) is caused by prolonged tachycardia leading to dilatation and systolic dysfunction with clinical manifestation of heart failure. This state is reversible after normalization of heart rate. The diagnosis is usually made retrospectively after normalization of heart rate and recovery of left ventricular function (LVF). More than 100 years after the first documented case (described in 1913 in a young patient with atrial fibrillation and symptoms of heart failure [25]) is still limited knowledge of pathophysiological mechanisms. The most common arrhythmias responsible for the TIC include atrial fibrillation [1,2], atrial flutter [3], incessant supraventricular tachycardia [4], ventricular tachycardia (VT) [5] and frequent ventricular extrasystoles (VES) [6]. TIC detection and therapeutic intervention is crucial considering potential reversibility of tachycardia. Current options of treatment involve drug therapy and surgical or catheter ablation.

  4. Radiation-Induced Bioradicals

    NASA Astrophysics Data System (ADS)

    Lahorte, Philippe; Mondelaers, Wim

    This chapter represents the second part of a review in which the production and application of radiation-induced radicals in biological matter are discussed. In part one the general aspects of the four stages (physical, physicochemical, chemical and biological) of interaction of radiation with matter in general and biological matter in particular, were discussed. Here an overview is presented of modem technologies and theoretical methods available for studying these radiation effects. The relevance is highlighted of electron paramagnetic resonance spectroscopy and quantum chemical calculations with respect to obtaining structural information on bioradicals, and a survey is given of the research studies in this field. We also discuss some basic aspects of modem accelerator technologies which can be used for creating radicals and we conclude with an overview of applications of radiation processing in biology and related fields such as biomedical and environmental engineering, food technology, medicine and pharmacy.

  5. [Cannabis-induced disorders].

    PubMed

    Soyka, M; Preuss, U; Hoch, E

    2017-03-01

    Use and misuse of cannabis and marihuana are frequent. About 5% of the adult population are current users but only 1.2% are dependent. The medical use of cannabis is controversial but there is some evidence for improvement of chronic pain and spasticity. The somatic toxicity of cannabis is well proven but limited and psychiatric disorders induced by cannabis are of more relevance, e.g. cognitive disorders, amotivational syndrome, psychoses and delusional disorders as well as physical and psychological dependence. The withdrawal symptoms are usually mild and do not require pharmacological interventions. To date there is no established pharmacotherapy for relapse prevention. Psychosocial interventions include psychoeducation, behavioral therapy and motivational enhancement. The CANDIS protocol is the best established German intervention among abstinence-oriented therapies.

  6. Catatonia induced by levetiracetam.

    PubMed

    Chouinard, Marie-Josée; Nguyen, Dang-Khoa; Clément, Jean-François; Bruneau, Marie-Andrée

    2006-02-01

    Levetiracetam (Keppra) is a novel antiepileptic drug approved as adjunctive treatment for adults with partial onset seizures. Although the drug is generally well tolerated, behavioral side effects have been reported in variable frequency. Most behavioral problems are mild in nature (agitation, hostility, anxiety, emotional lability, apathy, depression) and quickly resolve with discontinuation of medication. However, serious psychiatric adverse events may also occur with rare cases of psychosis and suicidal behavior. We report here the case of a 43-year-old woman who developed symptoms compatible with catatonia after being exposed to levetiracetam for the treatment of epilepsy. To our knowledge, it is the first reported case of catatonia induced by levetiracetam. We review the difficulties that may be encountered in the differential diagnosis of medical catatonia.

  7. Gadolinium-Induced Fibrosis.

    PubMed

    Todd, Derrick J; Kay, Jonathan

    2016-01-01

    Gadolinium-based contrast agents (GBCAs), once believed to be safe for patients with renal disease, have been strongly associated with nephrogenic systemic fibrosis (NSF), a severe systemic fibrosing disorder that predominantly afflicts individuals with advanced renal dysfunction. We provide a historical perspective on the appearance and disappearance of NSF, including its initial recognition as a discrete clinical entity, its association with GBCA exposure, and the data supporting a causative relationship between GBCA exposure and NSF. On the basis of this body of evidence, we propose that the name gadolinium-induced fibrosis (GIF) more accurately reflects the totality of knowledge regarding this disease. Use of high-risk GBCAs, such as formulated gadodiamide, should be avoided in patients with renal disease. Restriction of GBCA use in this population has almost completely eradicated new cases of this debilitating condition. Emerging antifibrotic therapies may be useful for patients who suffer from GIF.

  8. [Designer drug induced psychosis].

    PubMed

    Fullajtar, Mate; Ferencz, Csaba

    2012-06-01

    3,4-methylene-dioxy-pyrovalerone (MDPV) is a popular designer drug in Hungary, known as MP4. We present a case of a 34-year-old man, whose first psychotic episode was observed in the presence of MP4 use. The paranoid ideas of reference and the dereistic thinking could be the consequence of drug-induced psychosis. Within 24 hours after the intoxication was over delirium set in. The patient's history included only the use of MP4, use of other kinds of drugs was negated. The drug tests were negative, amphetamine derivates were not detectable in the urine sample. It is most likely that the MP4 pill contained an amount of MDPV less than detectable. In conclusion we suggest that the clinical picture could be the consequence of regular MDPV use.

  9. Laser-induced bioluminescence

    SciTech Connect

    Hickman, G.D.; Lynch, R.V. III

    1981-01-01

    A project has been initiated to determine the feasibility of developing a complete airborne remote sensing system for rapidly mapping high concentration patches of bioluminescent organisms in the world's oceans. Conceptually, this system would be composed of a laser illuminator to induce bioluminescence and a low light level image intensifier for detection of light. Initial laboratory measurements consisted of using a 2-J flash lamp pulsed optical dye laser to excite bioluminescence in the marine dinoflagellate Pyrocustis lunula at ambient temperature using Rhodamine 6G as the lasing dye (585 nm) and a laser pulse width of 1 microsec. After a latency period of 15-20 msec, the bioluminescence maximum occurred in the blue (480 nm is the wavelength maximum for most dinoflagellate bioluminescence) with the peaking occurring approximately 65 msec after the laser pulse. Planned experiments will investigate the effect of different excitation wavelengths and energies at various temperatures and salinities of the cultures.

  10. Radiation Induced Oral Mucositis

    PubMed Central

    PS, Satheesh Kumar; Balan, Anita; Sankar, Arun; Bose, Tinky

    2009-01-01

    Patients receiving radiotherapy or chemotherapy will receive some degree of oral mucositis The incidence of oral mucositis was especially high in patients: (i) With primary tumors in the oral cavity, oropharynx, or nasopharynx; (ii) who also received concomitant chemotherapy; (iii) who received a total dose over 5,000 cGy; and (iv) who were treated with altered fractionation radiation schedules. Radiation-induced oral mucositis affects the quality of life of the patients and the family concerned. The present day management of oral mucositis is mostly palliative and or supportive care. The newer guidelines are suggesting Palifermin, which is the first active mucositis drug as well as Amifostine, for radiation protection and cryotherapy. The current management should focus more on palliative measures, such as pain management, nutritional support, and maintenance, of good oral hygiene PMID:20668585

  11. [Drug-induced asterixis].

    PubMed

    Rittmannsberger, H; Leblhuber, F

    1994-04-22

    A 54-year-old woman with acute schizoaffective psychosis was treated with lithium carbonate (1,350 mg daily) and zuclopenthixol. On admission, clozapine was added (250 mg daily). Because extrapyramidal symptoms (rigor, akinesia) developed, she was additionally given biperiden retard (4 mg daily) from the fourth hospital day onwards. Eleven days after admission she began to complain of "unsteadiness" and "tremors" in her arms and she had asterixis (flapping tremor) on holding up her arms. The electromyogram showed electrical pauses of 60-120 ms, typical for asterixis. There were no significant metabolic or organic cerebral changes that could have accounted for the symptoms which presumably had been induced by the drugs even though their dosage was not unusual. The symptoms in fact regressed completely after the clozapine dose had been reduced, at first to 125 mg then to 50 mg. Previous experience has suggested that the risk of asterixis is particularly high when lithium and clozapine are taken together.

  12. Load Induced Blindness

    PubMed Central

    Macdonald, James S. P.; Lavie, Nilli

    2008-01-01

    Although the perceptual load theory of attention has stimulated a great deal of research, evidence for the role of perceptual load in determining perception has typically relied on indirect measures that infer perception from distractor effects on reaction times or neural activity (see N. Lavie, 2005d`) was consistently reduced with high, compared to low, perceptual load but was unaffected by the level of working memory load. Because alternative accounts in terms of expectation, memory, response bias, and goal-neglect due to the more strenuous high load task were ruled out, these experiments clearly demonstrate that high perceptual load determines conscious perception, impairing the ability to merely detect the presence of a stimulus—a phenomenon of load induced blindness. PMID:18823196

  13. DNA Damage Induced Neuronal Death

    DTIC Science & Technology

    1999-10-01

    Experiments are proposed to examine the molecular mechanism by which mustard chemical warfare agents induce neuronal cell death . DNA damage is the...proposed underlying mechanism of mustard-induced neuronal cell death . We propose a novel research strategy to test this hypothesis by using mice with...perturbed DNA repair to explore the relationship between mustard-induced DNA damage and neuronal cell death . Initial in vitro studies (Years 1, 2 & 3

  14. Pertussis-induced cough.

    PubMed

    Wang, Kay; Harnden, Anthony

    2011-06-01

    Pertussis (whooping cough) is one of the commonest vaccine preventable diseases in the UK, despite vaccination coverage being maintained for the last 15 years at over 90% among infants and the addition of a pre-school booster to the UK national immunisation programme in 2001. However, it is known that pertussis vaccine does not confer long-term immunity to clinical infection. Evidence of pertussis infection has been reported in 37% of children presenting in UK primary care and 20% of adolescents and adults presenting in Canadian health centres with persistent cough. In children and adults with persistent cough, paroxysmal coughing is the most sensitive indicator of pertussis, but has poor specificity and limited diagnostic value. Vomiting and whooping, particularly in combination, are stronger predictors of pertussis. Cough duration is longer in children than in adults with pertussis (median cough duration 112 days versus 42 days); individuals may take even longer to recover fully and regain previous levels of exercise tolerance. A diagnosis of pertussis may be confirmed by culture, Polymerase Chain Reaction (PCR) or serology. Single estimates of anti-pertussis toxin (PT) antibody titres in blood or oral fluid samples are highly specific. There are currently no proven efficacious treatments for pertussis-induced cough. Treatment with macrolide antibiotics reduces the duration of an individual's infectious period, but does not alter the duration of cough. Further research is needed to re-examine the epidemiology of pertussis in countries with different vaccination schedules, find efficacious treatments and develop methods of measuring cough frequency and severity in patients with pertussis-induced cough.

  15. Bellows flow-induced vibrations

    NASA Technical Reports Server (NTRS)

    Tygielski, P. J.; Smyly, H. M.; Gerlach, C. R.

    1983-01-01

    The bellows flow excitation mechanism and results of comprehensive test program are summarized. The analytical model for predicting bellows flow induced stress is refined. The model includes the effects of an upstream elbow, arbitrary geometry, and multiple piles. A refined computer code for predicting flow induced stress is described which allows life prediction if a material S-N diagram is available.

  16. Fishbone-induced perforated appendicitis.

    PubMed

    Bababekov, Yanik J; Stanelle, Eric J; Abujudeh, Hani H; Kaafarani, Haytham M A

    2015-05-20

    We review the literature and describe a case of fishbone-induced appendicitis. A 63-year-old man presented with abdominal pain. Work up including a focused history and imaging revealed fishbone-induced perforated appendicitis. The patient was managed safely and successfully with laparoscopic removal of the foreign body and appendectomy.

  17. Clofibrate-Induced Antidiuresis

    PubMed Central

    Moses, Arnold M.; Howanitz, Joan; Gemert, Marcia Van; Miller, Myron

    1973-01-01

    Normal subjects and patients with antidiuretic hormone (ADH) deficiency were studied to determine the mechanism of the antidiuretic action of clofibrate. Before clofibrate treatment, the patients' ability to concentrate urine with a standardized dehydration procedure correlated with the amount of ADH which was excreted. During clofibrate administration all six patients with ADH deficiency developed an antidiuresis which was like that of ADH, since there was no change in sodium, potassium, total solute, or creatinine excretion. There was a correlation between the patients' ability to concentrate urine during dehydration and the subsequent response to clofibrate, and the excretion of ADH during dehydration correlated with the excretion of ADH on clofibrate therapy. Clofibrate-induced antidiuresis in these patients was partially overcome by ethanol and by water loading. Clofibrate interfered with the ability of patients and subjects to excrete a water load and prevented the water load from inhibiting ADH excretion in the normal subjects. These studies suggested that clofibrate was acting through endogenous ADH and this thesis was supported by the failure of clofibrate to produce an antidiuresis when injected into rats with total ADH deficiency (Brattleboro strain) although an antidiuresis was produced in water-loaded normal rats. When the drug was injected into Brattleboro rats with exogenous ADH, clofibrate either did not alter or it inhibited the action of the ADH. The data demonstrate that clofibrate has a significant ADH-like action. This action appears to be mediated through the release of endogenous ADH. Images PMID:4685079

  18. Chemotherapy-induced alopecia.

    PubMed

    Trüeb, Ralph M

    2009-03-01

    Few dermatologic conditions carry as much emotional distress as chemotherapy-induced alopecia (CIA). The prerequisite for successful development of strategies for CIA prevention is the understanding of the pathobiology of CIA. The incidence and severity of CIA are variable and related to the particular chemotherapeutic protocol. CIA is traditionally categorized as acute diffuse hair loss caused by dystrophic anagen effluvium; however, CIA presents with different clinical patterns of hair loss. When an arrest of mitotic activity occurs, obviously numerous and interacting factors influence the shedding pattern. The major approach to minimize CIA is by scalp cooling. Unfortunately, most published data on scalp cooling are of poor quality. Several experimental approaches to the development of pharmacologic agents are under evaluation and include drug-specific antibodies, hair growth cycle modifiers, cytokines and growth factors, antioxidants, inhibitors of apoptosis, and cell-cycle and proliferation modifiers. Ultimately, the protection should be selective to the hair follicle; for example, topical application, such that the anticancer efficacy of chemotherapy is not hampered. Among the few agents that have been evaluated so far in humans, AS101 and minoxidil were able to reduce the severity or shorten the duration of CIA, but could not prevent CIA.

  19. [Cold-induced urticaria].

    PubMed

    Delorme, N; Drouet, M; Thibaudeau, A; Verret, J L

    2002-09-01

    Cold urticaria is characterized by the development of urticaria, usually superficial and/or angioedematous reaction after cold contact. It was found predominantly in young women. The diagnosis is based on the history and ice cube test. Patients with a negative ice cube test may have represented systemic cold urticaria (atypical acquired cold urticaria) induced by general body cooling. The pathogenesis is poorly understood. Cold urticaria can be classified into acquired and familial disorders, with an autosomal dominant inheritance. Idiopathic cold urticaria is most common type but the research of a cryopathy is necessary. Therapy is often difficult. It is essential that the patient be warned of the dangers of swimming in cold water because systemic hypotension can occur. H1 antihistamines can be used for treatment of cold urticaria but the clinical responses are highly variable. The combination with an H2 antagonists is more effective. Doxepin may be useful in the treatment. Leukotriene receptor antagonists may be a novel, promising drug entity. In patients who do not respond to previous treatments, induction of cold tolerance may be tried.

  20. Discreteness inducing coexistence

    NASA Astrophysics Data System (ADS)

    dos Santos, Renato Vieira

    2013-12-01

    Consider two species that diffuse through space. Consider further that they differ only in initial densities and, possibly, in diffusion constants. Otherwise they are identical. What happens if they compete with each other in the same environment? What is the influence of the discrete nature of the interactions on the final destination? And what are the influence of diffusion and additive fluctuations corresponding to random migration and immigration of individuals? This paper aims to answer these questions for a particular competition model that incorporates intra and interspecific competition between the species. Based on mean field theory, the model has a stationary state dependent on the initial density conditions. We investigate how this initial density dependence is affected by the presence of demographic multiplicative noise and additive noise in space and time. There are three main conclusions: (1) Additive noise favors denser populations at the expense of the less dense, ratifying the competitive exclusion principle. (2) Demographic noise, on the other hand, favors less dense populations at the expense of the denser ones, inducing equal densities at the quasi-stationary state, violating the aforementioned principle. (3) The slower species always suffers the more deleterious effects of statistical fluctuations in a homogeneous medium.

  1. Laughter-induced syncope.

    PubMed

    Kim, Alexander J; Frishman, William H

    2012-01-01

    Reported cases of syncope caused directly by laughter are rare. The common scenario described in a few reports involved episodes of fortuitous laughter, sometimes followed by a short prodrome of lightheadedness, facial flushing, and dizziness, followed by an episode of definite syncope. There were no seizure-like movements, automatisms, or bladder or bowel incontinence. After the syncopal episodes that were seconds in length, the patients regained consciousness, and at that point were fully oriented. These episodes could recur in a similar situation with such laughter. Many of these patients subsequently underwent full syncope workups, without elucidating a primary cardiac or neurologic cause. In this review of laughter-induced syncope, we describe a patient of ours who fit these descriptions. This phenomenon is likely a subtype of benign Valsalva-related syncope, with autonomic reflex arcs coming into play that ultimately result in global cerebral hypoperfusion. Besides the Valsalva produced by a great fit of laughter, laughter itself has its own neuroendocrine and vasculature effects that may play a role.

  2. Inductive source induced polarization

    NASA Astrophysics Data System (ADS)

    Marchant, David; Haber, Eldad; Oldenburg, Douglas W.

    2013-02-01

    Induced polarization (IP) surveys are commonly performed to map the distribution of electrical chargeability that is a diagnostic physical property in mineral exploration and in many environmental problems. Although these surveys have been successful in the past, the galvanic sources required for traditional IP and magnetic IP (MIP) surveys prevent them from being applied in some geological settings. We develop a new methodology for processing frequency domain EM data to identify the presence of IP effects in observations of the magnetic fields arising from an inductive source. The method makes use of the asymptotic behaviour of the secondary magnetic fields at low frequency. A new quantity, referred to as the ISIP datum, is defined so that it equals zero at low frequencies for any frequency-independent (non-chargeable) conductivity distribution. Thus, any non-zero response in the ISIP data indicates the presence of chargeable material. Numerical simulations demonstrate that the method can be applied even in complicated geological situations. A 3-D inversion algorithm is developed to recover the chargeability from the ISIP data and the inversion is demonstrated on synthetic examples.

  3. Load induced blindness.

    PubMed

    Macdonald, James S P; Lavie, Nilli

    2008-10-01

    Although the perceptual load theory of attention has stimulated a great deal of research, evidence for the role of perceptual load in determining perception has typically relied on indirect measures that infer perception from distractor effects on reaction times or neural activity (see N. Lavie, 2005, for a review). Here we varied the level of perceptual load in a letter-search task and assessed its effect on the conscious perception of a search-irrelevant shape stimulus appearing in the periphery, using a direct measure of awareness (present/absent reports). Detection sensitivity (d') was consistently reduced with high, compared to low, perceptual load but was unaffected by the level of working memory load. Because alternative accounts in terms of expectation, memory, response bias, and goal-neglect due to the more strenuous high load task were ruled out, these experiments clearly demonstrate that high perceptual load determines conscious perception, impairing the ability to merely detect the presence of a stimulus--a phenomenon of load induced blindness.

  4. Loperamide-induced hypopituitarism

    PubMed Central

    Napier, Catherine; Gan, Earn H; Pearce, Simon H S

    2016-01-01

    Loperamide is the most commonly used antidiarrhoeal medication in the UK. We report a serious and hitherto undocumented adverse effect of chronic use in a 45-year-old man with inflammatory bowel disease. He presented to the endocrine clinic with fatigue and low libido; biochemical assessment revealed hypogonadism and adrenal insufficiency without any elevated adrenocorticotropic hormone. When symptoms allowed, loperamide was reduced and a short synacthen test (SST) showed a ‘clear pass’ with a normal peak cortisol of 833 nmol/L. Later, worsening diarrhoea necessitated an escalation in loperamide use again. While taking a daily dose of 15–20 mg (recommended daily maximum 16 mg) reassessment revealed a fall in peak cortisol on SST to 483 nmol/L, a subnormal response. Clinicians should exercise caution when relying on loperamide to manage their patients’ chronic diarrhoea and remain mindful of the possibility of drug-induced life-threatening adrenal insufficiency. PMID:27681351

  5. Extreme geomagnetically induced currents

    NASA Astrophysics Data System (ADS)

    Kataoka, Ryuho; Ngwira, Chigomezyo

    2016-12-01

    We propose an emergency alert framework for geomagnetically induced currents (GICs), based on the empirically extreme values and theoretical upper limits of the solar wind parameters and of d B/d t, the time derivative of magnetic field variations at ground. We expect this framework to be useful for preparing against extreme events. Our analysis is based on a review of various papers, including those presented during Extreme Space Weather Workshops held in Japan in 2011, 2012, 2013, and 2014. Large-amplitude d B/d t values are the major cause of hazards associated with three different types of GICs: (1) slow d B/d t with ring current evolution (RC-type), (2) fast d B/d t associated with auroral electrojet activity (AE-type), and (3) transient d B/d t of sudden commencements (SC-type). We set "caution," "warning," and "emergency" alert levels during the main phase of superstorms with the peak Dst index of less than -300 nT (once per 10 years), -600 nT (once per 60 years), or -900 nT (once per 100 years), respectively. The extreme d B/d t values of the AE-type GICs are 2000, 4000, and 6000 nT/min at caution, warning, and emergency levels, respectively. For the SC-type GICs, a "transient alert" is also proposed for d B/d t values of 40 nT/s at low latitudes and 110 nT/s at high latitudes, especially when the solar energetic particle flux is unusually high.

  6. Endopolyploidy in irradiated p53-deficient tumour cell lines: Persistence of cell division activity in giant cells expressing Aurora B- kinase

    PubMed Central

    Erenpreisa, Jekaterina; Ivanov, Andrei; Wheatley, Sally P; Kosmacek, Elizabeth A; Ianzini, Fiorenza; Anisimov, Alim P; Mackey, Michael; Davis, Paul J; Plakhins, Grigorijs; Illidge, Timothy M

    2008-01-01

    Recent findings including computerized live imaging suggest that polyploidy cells transiently emerging after severe genotoxic stress (and named ‘endopolyploid cells’) may have a role in tumour regrowth after anti-cancer treatment. Until now, mostly the factors enabling metaphase were studied in them. Here we investigate the mitotic activities and the role of Aurora B, in view of potential de-polyploidisation of these cells, because Aurora B- kinase is responsible for coordination and completion of mitosis. We observed that endopolyploid giant cells are formed in irradiated p53 tumours in several ways: (1) by division/fusion of daughter cells creating early multi-nucleated cells; (2) by asynchronous division/fusion of sub-nuclei of these multinucleated cells; (3) by a series of polyploidising mitoses reverting replicative interphase from aborted metaphase and forming giant cells with a single nucleus; (4) by micronucleation of arrested metaphases enclosing genome fragments; or (5) by incomplete division in the multipolar mitoses forming late multi-nucleated giant cells. We also observed that these activities are able to release para-diploid cells, although they do so infrequently. Although after a substantial delay, apoptosis typically occurs in these cells, we also found that roughly 2% of endopolyploid cells evade apoptosis and senescence arrest and continue mitotic activities. In this article we describe that catalytically active aurora B-kinase is expressed in the nuclei of many interphase endopolyploid cells, as well as being present at the centromeres, mitotic spindle and cleavage furrow during their mitotic efforts. The totally micronucleated giant cells (containing subgenomic fragments in multiple micronuclei) represented the only minor fraction, which failed to undergo mitosis and Aurora B was absent from it. These observations suggest that most endopolyploid tumour cells are not reproductively inert and that aurora B may contribute to the establishment

  7. Drug-Induced Metabolic Acidosis

    PubMed Central

    Pham, Amy Quynh Trang; Xu, Li Hao Richie; Moe, Orson W.

    2015-01-01

    Metabolic acidosis could emerge from diseases disrupting acid-base equilibrium or from drugs that induce similar derangements. Occurrences are usually accompanied by comorbid conditions of drug-induced metabolic acidosis, and clinical outcomes may range from mild to fatal. It is imperative that clinicians not only are fully aware of the list of drugs that may lead to metabolic acidosis but also understand the underlying pathogenic mechanisms. In this review, we categorized drug-induced metabolic acidosis in terms of pathophysiological mechanisms, as well as individual drugs’ characteristics. PMID:26918138

  8. Pregnancy-Induced hypertension.

    PubMed

    Kintiraki, Evangelia; Papakatsika, Sophia; Kotronis, George; Goulis, Dimitrios G; Kotsis, Vasilios

    2015-01-01

    Pregnancy-induced hypertension (PIH) complicates 6-10% of pregnancies. It is defined as systolic blood pressure (SBP) >140 mmHg and diastolic blood pressure (DBP) >90 mmHg. It is classified as mild (SBP 140-149 and DBP 90-99 mmHg), moderate (SBP 150-159 and DBP 100-109 mmHg) and severe (SBP ≥ 160 and DBP ≥ 110 mmHg). PIH refers to one of four conditions: a) pre-existing hypertension, b) gestational hypertension and preeclampsia (PE), c) pre-existing hypertension plus superimposed gestational hypertension with proteinuria and d) unclassifiable hypertension. PIH is a major cause of maternal, fetal and newborn morbidity and mortality. Women with PIH are at a greater risk of abruptio placentae, cerebrovascular events, organ failure and disseminated intravascular coagulation. Fetuses of these mothers are at greater risk of intrauterine growth retardation, prematurity and intrauterine death. Ambulatory blood pressure monitoring over a period of 24 h seems to have a role in predicting deterioration from gestational hypertension to PE. Antiplatelet drugs have moderate benefits when used for prevention of PE. Treatment of PIH depends on blood pressure levels, gestational age, presence of symptoms and associated risk factors. Non-drug management is recommended when SBP ranges between 140-149 mmHg or DBP between 90-99 mmHg. Blood pressure thresholds for drug management in pregnancy vary between different health organizations. According to 2013 ESH/ESC guidelines, antihypertensive treatment is recommended in pregnancy when blood pressure levels are ≥ 150/95 mmHg. Initiation of antihypertensive treatment at values ≥ 140/90 mmHg is recommended in women with a) gestational hypertension, with or without proteinuria, b) pre-existing hypertension with the superimposition of gestational hypertension or c) hypertension with asymptomatic organ damage or symptoms at any time during pregnancy. Methyldopa is the drug of choice in pregnancy. Atenolol and metoprolol appear to be

  9. Drug-induced urinary calculi.

    PubMed

    Matlaga, Brian R; Shah, Ojas D; Assimos, Dean G

    2003-01-01

    Urinary calculi may be induced by a number of medications used to treat a variety of conditions. These medications may lead to metabolic abnormalities that facilitate the formation of stones. Drugs that induce metabolic calculi include loop diuretics; carbonic anhydrase inhibitors; and laxatives, when abused. Correcting the metabolic abnormality may eliminate or dramatically attenuate stone activity. Urinary calculi can also be induced by medications when the drugs crystallize and become the primary component of the stones. In this case, urinary supersaturation of the agent may promote formation of the calculi. Drugs that induce calculi via this process include magnesium trisilicate; ciprofloxacin; sulfa medications; triamterene; indinavir; and ephedrine, alone or in combination with guaifenesin. When this situation occurs, discontinuation of the medication is usually necessary.

  10. Phentermine induced acute interstitial nephritis.

    PubMed

    Shao, Emily Ximin; Wilson, Gregory John; Ranganathan, Dwarakanathan

    2017-03-09

    Acute interstitial nephritis (AIN) has a number of medication-related aetiologies. Antibiotics, proton pump inhibitors and non-steroidal anti-inflammatory drugs are common causes; however, any medication has the potential to cause drug-induced AIN. We report the first case of phentermine-induced AIN. A Caucasian woman aged 43 years presented with a 5-week history of lethargy, left-sided lower abdominal pain, nausea and vomiting. She had been taking phentermine for weight loss for 9 months and had recently ceased the medication. The patient underwent a renal biopsy that showed a predominantly lymphohistiocytic interstitial infiltrate with a moderate number of eosinophils consistent with AIN. Phentermine is increasingly used for weight loss in obese patients. This is the first case implicating phentermine as the causative agent for drug-induced AIN. While rare, phentermine-induced AIN is a possible adverse reaction of phentermine. Physicians and patients need to be aware of this risk.

  11. Groundwater: Climate-induced pumping

    NASA Astrophysics Data System (ADS)

    Gurdak, Jason J.

    2017-01-01

    Groundwater resources are directly affected by climate variability via precipitation, evapotranspiration and recharge. Analyses of US and India trends reveal that climate-induced pumping indirectly influences groundwater depletion as well.

  12. Drug-induced lupus erythematosus

    MedlinePlus

    ... Causes Drug-induced lupus erythematosus is similar to systemic lupus erythematosus (SLE). It is an autoimmune disorder. This means ... 2015:chap 132. Wright B, Bharadwaj S, Abelson A. Systemic lupus erythematosus. In: Carey WD, ed. Cleveland Clinic: Current Clinical ...

  13. Victim-induced criminality.

    PubMed

    Fooner, M

    1966-09-02

    about the probable effects on the administration of criminal justice. These are pragmatic problems; there is a third problem which may at this time seem speculative, but is, nevertheless, quite important. 3) To what extent will a particular proposal for victim compensation contribute to a temptation-opportunity pattern in victim behavior? In previous studies it has been pointed out that large numbers of our fellow Americans have tended to acquire casual money-handling habits-generically designated "carelessness"-which contribute to the national growth of criminality. How the victim helps the criminal was sketched in reports of those studies (10). It was made abundantly clear that human beings in our affluent society cannot be assumed to be prudent or self-protective against the hazards of crime. Even when the "victim" is not overtly acting to commit a crime-as in the case of the property owner who hires an arsonist-he often tempts the offender. Among the victims of burglary-statistically the most prevalent crime in the United States-are a substantial number of Americans who keep cash, jewelry, and other valuables carelessly at home or in hotel rooms to which the burglar has easy access through door or window. Victims of automobile theft-one of the fastest growing classes of crime-include drivers who leave the vehicle or its contents invitingly accessible to thieves. And so on with other classes of crime. As pointed out in previous studies, when victim behavior follows a temptation-opportunity pattern, it (i) contributes to a "climate of criminal inducements," (ii) adds to the economic resources available to criminal societies, and (iii) detracts from the ability of lawenforcement agencies to suppress the growth of crime.

  14. Reprogramming with defined factors: from induced pluripotency to induced transdifferentiation.

    PubMed

    Masip, Manuel; Veiga, Anna; Izpisúa Belmonte, Juan Carlos; Simón, Carlos

    2010-11-01

    Ever since work on pluripotency induction was originally published, reporting the reprogramming of somatic cells to induced pluripotent stem cells (iPS cells) by the ectopic expression of the four transcription factors Oct4, Sox2, Klf4 and c-Myc, high expectations regarding their potential use for regenerative medicine have emerged. Very recently, the direct conversion of fibroblasts into functional neurons with no prior pluripotent stage has been described. Interconversion between adult cells from ontogenically different lineages by an induced transdifferentiation process based on the overexpression of a cocktail of transcription factors, while avoiding transition through an embryonic stem cell-like state, provides a new impetus in the field of regenerative medicine. Here, we review the induced reprogramming of somatic cells with defined factors and analyze their potential clinical use. Beginning with induced pluripotency, we summarize the initial objections including their extremely low efficiency and the risk of tumor generation. We also review recent reports describing iPS cells' capacity to generate viable offspring through tetraploid complementation, the most restrictive pluripotency criterion. Finally, we explore the available evidence for 'induced transdifferentiated cells' as a novel tool for adult cell fate modification.

  15. Lattice-Induced Frequency Shifts in Sr Optical Lattice Clocks at the 10{sup -17} Level

    SciTech Connect

    Westergaard, P. G.; Lodewyck, J.; Lecallier, A.; Millo, J.; Lemonde, P.; Lorini, L.; Burt, E. A.; Zawada, M.

    2011-05-27

    We present a comprehensive study of the frequency shifts associated with the lattice potential in a Sr lattice clock by comparing two such clocks with a frequency stability reaching 5x10{sup -17} after a 1 h integration time. We put the first experimental upper bound on the multipolar M1 and E2 interactions, significantly smaller than the recently predicted theoretical upper limit, and give a 30-fold improved upper limit on the effect of hyperpolarizability. Finally, we report on the first observation of the vector and tensor shifts in a Sr lattice clock. Combining these measurements, we show that all known lattice related perturbations will not affect the clock accuracy down to the 10{sup -17} level, even for lattices as deep as 150 recoil energies.

  16. Induced airflow in flying insects II. Measurement of induced flow.

    PubMed

    Sane, Sanjay P; Jacobson, Nathaniel P

    2006-01-01

    The flapping wings of insects and birds induce a strong flow over their body during flight. Although this flow influences the sensory biology and physiology of a flying animal, there are very little data on the characteristics of this self-generated flow field or its biological consequences. A model proposed in the companion paper estimated the induced flow over flying insects. In this study, we used a pair of hot wire anemometers to measure this flow at two locations near the body of a tethered flapping hawk moth, Manduca sexta. The axial inflow anemometer measured the airflow prior to its entry into the stroke plane, whereas the radial outflow anemometer measured the airflow after it crossed the stroke plane. The high temporal resolution of the hot wire anemometers allowed us to measure not only the mean induced flow but also subtle higher frequency disturbances occurring at 1-4 times the wing beat frequency. These data provide evidence for the predictions of a mathematical model proposed in the companion paper. Specifically, the absolute value of the measured induced flow matches the estimate of the model. Also, as predicted by the model, the induced flow varies linearly with wing beat frequency. Our experiments also show that wing flexion contributes significantly to the observed higher frequency disturbances. Thus, the hot wire anemometry technique provides a useful means to quantify the aerodynamic signature of wing flexion. The phasic and tonic components of induced flow influence several physiological processes such as convective heat loss and gas exchange in endothermic insects, as well as alter the nature of mechanosensory and olfactory stimuli to the sensory organs of a flying insect.

  17. Multi-Frequency and Multi-Polarization SAR Use at the Canadian Ice Service- An Operational Perspective

    NASA Astrophysics Data System (ADS)

    Arkett, Matt; De Abreu, Roger; Zagon, Tom; Flett, Dean; Dekorte, Jessica

    2010-12-01

    The Canadian Ice Service (CIS) has used both airborne and spaceborne synthetic aperture radar (SAR) data extensively for almost three decades in their daily ice monitoring operations. The prohibitive cost of operating aircraft has seen CIS become increasingly reliant on spaceborne data in recent years. In particular, single-polarization (HH) C-band SAR from the ERS series and RADARSAT-1 sateliites formed the backbone of all CIS' operational programs through the 1990s. A limitation of these earlier C-Band sensors was their inability to acquire data in more than one polarization. Envisat-ASAR provided CIS with its first look at dual-polarization SAR from space and an opportunity to prepare for the upcoming launch of RADARSAT-2. After a short post-launch evaluation, CIS adopted the routine use of dual-polarization RADARSAT-2 ScanSAR (HH+HV) in its ice operations in June 2009. The January 2006 launch of the JAXA ALOS satellite gave CIS its first opportunity to incorporate L-band SAR into its daily operations. As a partner in the North American Ice Service (NAIS), CIS began to receive ALOS-PALSAR data through the National Ice Centre (NIC) in the United States via the Alaska Satellite Facility node. CIS currently receives approximately 70 scenes/week covering the Western Arctic, Beaufort and Chukchi Sea areas.

  18. Glycine immunoreactivity of multipolar neurons in the ventral cochlear nucleus which project to the dorsal cochlear nucleus.

    PubMed

    Doucet, J R; Ross, A T; Gillespie, M B; Ryugo, D K

    1999-06-14

    Certain distinct populations of neurons in the dorsal cochlear nucleus are inhibited by a neural source that is responsive to a wide range of acoustic frequencies. In this study, we examined the glycine immunoreactivity of two types of ventral cochlear nucleus neurons (planar and radiate) in the rat which project to the dorsal cochlear nucleus (DCN) and thus, might be responsible for this inhibition. Previously, we proposed that planar neurons provided a tonotopic and narrowly tuned input to the DCN, whereas radiate neurons provided a broadly tuned input and thus, were strong candidates as the source of broadband inhibition (Doucet and Ryugo [1997] J. Comp. Neurol. 385:245-264). We tested this idea by combining retrograde labeling and glycine immunohistochemical protocols. Planar and radiate neurons were first retrogradely labeled by injecting biotinylated dextran amine into a restricted region of the dorsal cochlear nucleus. The labeled cells were visualized using streptavidin conjugated to indocarbocyanine (Cy3), a fluorescent marker. Sections that contained planar or radiate neurons were then processed for glycine immunocytochemistry using diaminobenzidine as the chromogen. Immunostaining of planar neurons was light, comparable to that of excitatory neurons (pyramidal neurons in the DCN), whereas immunostaining of radiate neurons was dark, comparable to that of glycinergic neurons (cartwheel cells in the dorsal cochlear nucleus and principal cells in the medial nucleus of the trapezoid body). These results are consistent with the hypothesis that radiate neurons in the ventral cochlear nucleus subserve the wideband inhibition observed in the dorsal cochlear nucleus.

  19. Preferred Ice Crystal Orientation Fabric Measurements within the Greenland Ice Sheet Using Multi-Polarization Radar Data

    NASA Astrophysics Data System (ADS)

    Velez-Gonzalez, J. A.; JiLu, L.; Leuschen, C.; Gogineni, P.; Van der Veen, C. J.; Tsoflias, G. P.; Drews, R.; Harish, A. R.

    2013-12-01

    Discharge of ice from the Greenland Ice Sheet to the ocean has increased significantly over the last 25 years due to the acceleration of important outlet glaciers. It was reported that the Greenland Ice Sheet contributed about 2.5 m out of about 6 m of sea-level rise during the Eemian interglacial period. The temperatures during Eemian were reported to be about 8o×4o C higher than the mean of the past millennium. Laboratory measurements have shown that glacial ice, characterized by preferred crystal orientation fabric (COF), is three times more deformable than ice with randomly oriented crystalline structures. Layers characterized by preferred ice COF can influence the flow behavior of a glacier or ice sheet. However, COF measurements are typically obtained from ice cores, and thus are very spatially limited and mostly constrained to areas with little ice flow. A more efficient technique to map the extent of ice fabric over larger regions of ice sheets is needed to better understand the effects on large scale ice flow processes. Radar measurements are capable of discriminating between reflections caused by changes in density, electrical permittivity and COF by exploiting the anisotropic and birefringent properties of ice crystals. For this investigation two radar datasets were collected during the survey of the Greenland Eemian Ice Drilling Site (77.45°N 51.06°W) in August 2008, using a ground-based and chirped-pulse Multi-Channel Radar Depth Sounder (MCRDS) developed by the Center for Remote Sensing of Ice Sheets (CReSIS). The radar used two transmit and eight receive antennas at the center frequency of 150 MHz with a bandwidth of 30 MHz. The first data set consisted of polarimatric measurements acquired in a circular pattern (radius: 35 m) with two co-polarized antenna orientations (one transmitter and four receivers oriented with 90° offsets in the directions of the incident H-Field and E-Field, respectively). Analysis of the circular data shows a periodic power variation with four distinct extinction patterns occurring at 90 degree intervals starting at approximately 700 m depth. Furthermore a 20 degree phase change is observed between the E- and H-field data. Both observations suggest that approximately 72% of the 2542m ice column exhibits birefringent anisotropy caused by preferred ice crystal orientation. The second dataset was acquired in a grid pattern consisting of twenty 10-Km 2D lines (NW to SE) spaced at 0.5-Km and three 10-Km lines (NE to SW) spaced at 2.5-Km. Both transmit and eight receive antenna were oriented parallel to the vehicle track, resulting in E-Field co-polarized data. We will determine the dominant COF relative to the ice divide for a 100 square Km region around the NEEM camp using the results from both datasets. The results of this investigation will be compared to the NEEM ice core observations to determine the accuracy of the analysis. In this investigation we will provide a brief overview of the system and experiments and present the results of data analysis.

  20. Maternal inheritance of mitochondria: multipolarity, multiallelism and hierarchical transmission of mitochondrial DNA in the true slime mold Physarum polycephalum.

    PubMed

    Moriyama, Yohsuke; Kawano, Shigeyuki

    2010-03-01

    Direct evidence of digestion of paternal mitochondrial DNA (mtDNA) has been found in the true slime mold Physarum polycephalum. This is the first report on the selective digestion of mtDNA inside the zygote, and is striking evidence for the mechanism of maternal inheritance of mitochondria. Moreover, two mitochondrial nuclease activities were detected in this organism as-candidates for the nucleases responsible for selective digestion of mtDNA. In the true slime mold, there is an additional-feature of the uniparental inheritance of mitochondria.Although mitochondria are believed to be inherited from the maternal lineage in nearly all eukaryotes, the mating types of the true slime mold P. polycephalum is not restricted to two: there are three mating loci--matA, matB,and matC--and these loci have 16, 15, and 3 alleles,-respectively. Interestingly, the transmission patterns of mtDNA are determined by the matA locus, in a hierarchical-fashion (matA hierarchy) as follows: matA7[matA2[matA11[matA12[matA15/matA16[matA1[matA6.The strain possessing the higher status of matA would be the mtDNA donor in crosses. Furthermore, we have found that some crosses showed biparental inheritance of mitochondria.This review describes the phenomenon of hierarchical transmission of mtDNA in true slime molds, and discusses the presumed molecular mechanism of maternal and biparental inheritance.

  1. Jet-Induced Star Formation

    SciTech Connect

    van Breugel, W; Fragile, C; Anninos, P; Murray, S

    2003-12-16

    Jets from radio galaxies can have dramatic effects on the medium through which they propagate. We review observational evidence for jet-induced star formation in low ('FR-I') and high ('FR-II') luminosity radio galaxies, at low and high redshifts respectively. We then discuss numerical simulations which are aimed to explain a jet-induced starburst ('Minkowski's Object') in the nearby FR-I type radio galaxy NGC 541. We conclude that jets can induce star formation in moderately dense (10 cm{sup -3}), warm (10{sup 4} K) gas; that this may be more common in the dense environments of forming, active galaxies; and that this may provide a mechanism for 'positive' feedback from AGN in the galaxy formation process.

  2. Persistent nicorandil induced oral ulceration

    PubMed Central

    Healy, C M; Smyth, Y; Flint, S R

    2004-01-01

    Four patients with nicorandil induced ulceration are described, and the literature on the subject is reviewed. Nicorandil induced ulcers are very painful and distressing for patients. Clinically they appear as large, deep, persistent ulcers that have punched out edges. They are poorly responsive to topical steroids and usually require alteration of nicorandil treatment. The ulceration tends to occur at high doses of nicorandil and all four cases reported here were on doses of 40 mg per day or greater. In these situations reduction of nicorandil dose may be sufficient to promote ulcer healing and prevent further recurrence. However, nicorandil induced ulcers have been reported at doses as low as 10 mg daily and complete cessation of nicorandil may be required. PMID:15201264

  3. Validating induced seismicity forecast models—Induced Seismicity Test Bench

    NASA Astrophysics Data System (ADS)

    Király-Proag, Eszter; Zechar, J. Douglas; Gischig, Valentin; Wiemer, Stefan; Karvounis, Dimitrios; Doetsch, Joseph

    2016-08-01

    Induced earthquakes often accompany fluid injection, and the seismic hazard they pose threatens various underground engineering projects. Models to monitor and control induced seismic hazard with traffic light systems should be probabilistic, forward-looking, and updated as new data arrive. In this study, we propose an Induced Seismicity Test Bench to test and rank such models; this test bench can be used for model development, model selection, and ensemble model building. We apply the test bench to data from the Basel 2006 and Soultz-sous-Forêts 2004 geothermal stimulation projects, and we assess forecasts from two models: Shapiro and Smoothed Seismicity (SaSS) and Hydraulics and Seismics (HySei). These models incorporate a different mix of physics-based elements and stochastic representation of the induced sequences. Our results show that neither model is fully superior to the other. Generally, HySei forecasts the seismicity rate better after shut-in but is only mediocre at forecasting the spatial distribution. On the other hand, SaSS forecasts the spatial distribution better and gives better seismicity rate estimates before shut-in. The shut-in phase is a difficult moment for both models in both reservoirs: the models tend to underpredict the seismicity rate around, and shortly after, shut-in.

  4. Diapir-Induced Reorientation of Enceladus

    NASA Technical Reports Server (NTRS)

    Pappalardo, Robert T.; Nimno, Francis

    2006-01-01

    A viewgraph presentation on the diapir-induced reorientation of Enceladus is shown. The contents include: 1) Activity on Enceladus; 2) Miranda's Coronae: Origin above Diapirs; 3) Reorientation of Miranda; 4) Planetary Reorientation; 5) Modeling Diapir-Induced Reorientation; 6) Diapir-Induced Reorientation: Results; 7) Tectonic Implications of Reorientation; 8) Additional Tests of Reorientation; 9) Diapir-Induced Reorientation of Enceladus: Conclusions; and 10) Diapir-Induced Reorientation: Future Work

  5. Plasma rotation induced by RF

    SciTech Connect

    Chan, V. S.; Chiu, S. C.; Lin-Liu, Y. R. [General Atomics, P.O. Box 85608, San Diego, California 92186-5698; Omelchenko, Y. A. [General Atomics, P.O. Box 85608, San Diego, California 92186-5698

    1999-09-20

    Plasma rotation has many beneficial effects on tokamak operation including stabilization of MHD and microturbulence to improve the beta limit and confinement. Contrary to present-day tokamaks, neutral beams may not be effective in driving rotation in fusion reactors; hence the investigation of radiofrequency (RF) induced plasma rotation is of great interest and potential importance. This paper reviews the experimental results of RF induced rotation and possible physical mechanisms, suggested by theories, to explain the observations. This subject is only in the infancy of its research and many challenging issues remained to be understood and resolved. (c) 1999 American Institute of Physics.

  6. Induced radioactivity in LDEF components

    NASA Technical Reports Server (NTRS)

    Harmon, B. A.; Fishman, G. J.; Parnell, T. A.; Laird, C. E.

    1992-01-01

    A systematic study of the induced radioactivity of the Long Duration Exposure Facility (LDEF) is being carried out in order to gather information about the low earth orbit radiation environment and its effects on materials. The large mass of the LDEF spacecraft, its stabilized configuration, and long mission duration have presented an opportunity to determine space radiation-induced radioactivities with a precision not possible before. Data presented include preliminary activities for steel and aluminum structural samples, and activation subexperiment foils. Effects seen in the data show a clear indication of the trapped proton anisotropy in the South Atlantic Anomaly and suggest contributions from different sources of external radiation fluxes.

  7. Graphene with geometrically induced vorticity.

    PubMed

    Pachos, Jiannis K; Stone, Michael; Temme, Kristan

    2008-04-18

    At half filling, the electronic structure of graphene can be modeled by a pair of free two-dimensional Dirac fermions. We explicitly demonstrate that in the presence of a geometrically induced gauge field an everywhere-real Kekulé modulation of the hopping matrix elements can correspond to a nonreal Higgs field with nontrivial vorticity. This provides a natural setting for fractionally charged vortices with localized zero modes. For fullerenelike molecules we employ the index theorem to demonstrate the existence of six low-lying states that do not depend strongly on the Kekulé-induced mass gap.

  8. Efavirenz-induced exfoliative dermatitis.

    PubMed

    Zhang, Jiu-Cong; Sun, Yong-Tao

    2013-01-01

    Individuals with a human immunodeficiency virus (HIV) infection are at higher risk of developing adverse drug reactions. Multiple drugs are usually prescribed to patients with HIV infection for preventing the replication of HIV and for the treatment of the associated opportunistic infections. We report here the first case of an HIV-1-infected patient who developed an exfoliative dermatitis induced by efavirenz, a non-nucleoside reverse transcriptase inhibitor. Physicians should be aware of the possible occurrence of efavirenz-induced skin eruptions from the start of antiviral treatment of HIV infection.

  9. Method for induced polarization logging

    SciTech Connect

    Vinegar, H.J.; Waxman, M.H.

    1987-04-14

    A method is described for generating a log of the formation phase shift, resistivity and spontaneous potential of an earth formation from data obtained from the earth formation with a multi-electrode induced polarization logging tool. The method comprises obtaining data samples from the formation at measurement points equally spaced in time of the magnitude and phase of the induced voltage and the magnitude and phase of the current supplied by a circuit through a reference resistance R/sub 0/ to a survey current electrode associated with the tool.

  10. An induced junction photovoltaic cell

    NASA Technical Reports Server (NTRS)

    Call, R. L.

    1974-01-01

    Silicon solar cells operating with induced junctions rather than diffused junctions have been fabricated and tested. Induced junctions were created by forming an inversion layer near the surface of the silicon by supplying a sheet of positive charge above the surface. Measurements of the response of the inversion layer cell to light of different wavelengths indicated it to be more sensitive to the shorter wavelengths of the sun's spectrum than conventional cells. The greater sensitivity occurs because of the shallow junction and the strong electric field at the surface.

  11. Conflict-Induced Perceptual Filtering

    ERIC Educational Resources Information Center

    Wendt, Mike; Luna-Rodriguez, Aquiles; Jacobsen, Thomas

    2012-01-01

    In a variety of conflict paradigms, target and distractor stimuli are defined in terms of perceptual features. Interference evoked by distractor stimuli tends to be reduced when the ratio of congruent to incongruent trials is decreased, suggesting conflict-induced perceptual filtering (i.e., adjusting the processing weights assigned to stimuli…

  12. Photobiomodulation on alcohol induced dysfunction

    NASA Astrophysics Data System (ADS)

    Yang, Zheng-Ping; Liu, Timon C.; Zhang, Yan; Wang, Yan-Fang

    2007-05-01

    Alcohol, which is ubiquitous today, is a major health concern. Its use was already relatively high among the youngest respondents, peaked among young adults, and declined in older age groups. Alcohol is causally related to more than 60 different medical conditions. Overall, 4% of the global burden of disease is attributable to alcohol, which accounts for about as much death and disability globally as tobacco and hypertension. Alcohol also promotes the generation of reactive oxygen species (ROS) and/or interferes with the body's normal defense mechanisms against these compounds through numerous processes, particularly in the liver. Photobiomodulation (PBM) is a cell-specific effect of low intensity monochromatic light or low intensity laser irradiation (LIL) on biological systems. The cellular effects of both alcohol and LIL are ligand-independent so that PBM might rehabilitate alcohol induced dysfunction. The PBM on alcohol induced human neutrophil dysfunction and rat chronic atrophic gastritis, the laser acupuncture on alcohol addiction, and intravascular PBM on alcoholic coma of patients and rats have been observed. The endonasal PBM (EPBM) mediated by Yangming channel, autonomic nervous systems and blood cells is suggested to treat alcohol induced dysfunction in terms of EPBM phenomena, the mechanism of alcohol induced dysfunction and our biological information model of PBM. In our opinion, the therapeutic effects of PBM might also be achieved on alcoholic myopathy.

  13. Oxaliplatin-induced lung fibrosis

    PubMed Central

    Shah, Arpan; Udwadia, Zarir F.; Almel, Sachin

    2009-01-01

    Oxaliplatin has been approved for use as an adjuvant treatment in stage III colorectal carcinoma by the US-FDA. The majority of toxicity caused by this drug is manageable. However, rare, isolated cases of pulmonary fibrosis induced by this drug have been reported in literature. We report one such case of rapidly evolving pulmonary fibrosis following treatment with oxaliplatin. PMID:20838550

  14. Radiation-induced genomic instability

    NASA Technical Reports Server (NTRS)

    Kronenberg, A.

    1994-01-01

    Quantitative assessment of the heritable somatic effects of ionizing radiation exposures has relied upon the assumption that radiation-induced lesions were 'fixed' in the DNA prior to the first postirradiation mitosis. Lesion conversion was thought to occur during the initial round of DNA replication or as a consequence of error-prone enzymatic processing of lesions. The standard experimental protocols for the assessment of a variety of radiation-induced endpoints (cell death, specific locus mutations, neoplastic transformation and chromosome aberrations) evaluate these various endpoints at a single snapshot in time. In contrast with the aforementioned approaches, some studies have specifically assessed radiation effects as a function of time following exposure. Evidence has accumulated in support of the hypothesis that radiation exposure induces a persistent destabilization of the genome. This instability has been observed as a delayed expression of lethal mutations, as an enhanced rate of accumulation of non-lethal heritable alterations, and as a progressive intraclonal chromosomal heterogeneity. The genetic controls and biochemical mechanisms underlying radiation-induced genomic instability have not yet been delineated. The aim is to integrate the accumulated evidence that suggests that radiation exposure has a persistent effect on the stability of the mammalian genome.

  15. Adrafinil-induced orofacial dyskinesia.

    PubMed

    Thobois, Stéphane; Xie, Jing; Mollion, Helena; Benatru, Isabelle; Broussolle, Emmanuel

    2004-08-01

    We describe the first case of orofacial abnormal movements induced by adrafinil, a vigilance promoting agent of the same pharmacological class as modafinil. The dyskinesias did not spontaneously recover despite adrafinil withdrawal for a 4-month period. They were secondly dramatically improved by tetrabenazine, a presynaptic dopaminergic depleting drug which was introduced after the 4-month adrafinil-free period.

  16. Adolescents and Exercise Induced Asthma

    ERIC Educational Resources Information Center

    Hansen, Pamela; Bickanse, Shanna; Bogenreif, Mike; VanSickle, Kyle

    2008-01-01

    This article defines asthma and exercise induced asthma, and provides information on the triggers, signs, and symptoms of an attack. It also gives treatments for these conditions, along with prevention guidelines on how to handle an attack in the classroom or on the practice field. (Contains 2 tables and 1 figure.)

  17. [Readers' position against induced abortion].

    PubMed

    1981-08-25

    Replies to the request by the Journal of Nursing on readers' positions against induced abortion indicate there is a definite personal position against induced abortion and the assistance in this procedure. Some writers expressed an emotional "no" against induced abortion. Many quoted arguments from the literature, such as a medical dictionary definition as "a premeditated criminally induced abortion." The largest group of writers quoted from the Bible, the tenor always being: "God made man, he made us with his hands; we have no right to make the decision." People with other philosophies also objected. Theosophical viewpoint considers reincarnation and the law of cause and effect (karma). This philosophy holds that induced abortion impedes the appearance of a reincarnated being. The fundamental question in the abortion problem is, "can the fetus be considered a human life?" The German anatomist Professor E. Bleckschmidt points out that from conception there is human life, hence the fertilized cell can only develop into a human being and is not merely a piece of tissue. Professional nursing interpretation is that nursing action directed towards killing of a human being (unborn child) is against the nature and the essence of the nursing profession. A different opinion states that a nurse cares for patients who have decided for the operation. The nurse doesn't judge but respects the individual's decision. Some proabortion viewpoints considered the endangering of the mother's life by the unborn child, and the case of rape. With the arguments against abortion the question arises how to help the woman with unwanted pregnancy. Psychological counseling is emphasized as well as responsible and careful assistance. Referral to the Society for Protection of the Unborn Child (VBOK) is considered as well as other agencies. Further reader comments on this subject are solicited.

  18. An inducible offense: carnivore morph tadpoles induced by tadpole carnivory

    PubMed Central

    Levis, Nicholas A; de la Serna Buzón, Sofia; Pfennig, David W

    2015-01-01

    Phenotypic plasticity is commonplace, and plasticity theory predicts that organisms should often evolve mechanisms to detect and respond to environmental cues that accurately predict future environmental conditions. Here, we test this prediction in tadpoles of spadefoot toads, Spea multiplicata. These tadpoles develop into either an omnivore ecomorph, which is a dietary generalist, or a carnivore ecomorph, which specializes on anostracan shrimp and other tadpoles. We investigated a novel proximate cue – ingestion of Scaphiopus tadpoles – and its propensity to produce carnivores by rearing tadpoles on different diets. We found that diets containing tadpoles from the genus Scaphiopus produced more carnivores than diets without Scaphiopus tadpoles. We discuss why Scaphiopus tadpoles are an excellent food source and why it is therefore advantageous for S. multiplicata tadpoles to produce an inducible offense that allows them to better utilize this resource. In general, such inducible offenses provide an excellent setting for investigating the proximate and evolutionary basis of phenotypic plasticity. PMID:25897380

  19. Diuretic-induced hypokalaemia inducing torsades de pointes.

    PubMed

    Chvilicek, J P; Hurlbert, B J; Hill, G E

    1995-12-01

    Torsades de pointes (TP), an unique polymorphous type of ventricular tachycardia, is associated with either an acquired or congenitally prolonged QT interval. Several reports have demonstrated TP to follow an acquired prolonged QT interval secondary to chronic hypocalcaemia, hypomagnesaemia, or hypokalaemia. We report a rapid onset, acute extracellular hypokalaemia not associated with other electrolyte disturbances inducing a prolonged QT interval followed by TP. This is the first case report of a rapid onset isolated acute extracellular hypokalaemia inducing TP. Since anaesthetists are involved in therapies that will rapidly reduce extracellular potassium (diuretic, catecholamine, and/or insulin administration, hyperventilation), this cae report serves as a warning that such therapy may have the risk of arrhythmia induction.

  20. Distinguishing warming-induced drought from drought-induced warming

    NASA Astrophysics Data System (ADS)

    Roderick, M. L.; Yin, D.

    2015-12-01

    It is usually observed that temperatures, especially maximum temperatures are higher during drought. A very widely held public perception is that the increase in temperature is a cause of drought. This represents the warming-induced drought scenario. However, the agricultural and hydrologic scientific communities have a very different interpretation with drought being the cause of increasing temperature. In essence, those communities assume the warming is a surface feedback and their interpretation is for drought-induced warming. This is a classic cause-effect problem that has resisted definitive explanation due to the lack of radiative observations at suitable spatial and temporal scales. In this presentation we first summarise the observations and then use theory to untangle the cause-effect relationships that underlie the competing interpretations. We then show how satellite data (CERES, NASA) can be used to disentangle the cause-effect relations.

  1. Does a parthenogenesis-inducing Wolbachia induce vestigial cytoplasmic incompatibility?

    NASA Astrophysics Data System (ADS)

    Kraaijeveld, Ken; Reumer, Barbara M.; Mouton, Laurence; Kremer, Natacha; Vavre, Fabrice; van Alphen, Jacques J. M.

    2011-03-01

    Wolbachia is a maternally inherited bacterium that manipulates the reproduction of its host. Recent studies have shown that male-killing strains can induce cytoplasmic incompatibility (CI) when introgressed into a resistant host. Phylogenetic studies suggest that transitions between CI and other Wolbachia phenotypes have also occurred frequently, raising the possibility that latent CI may be widespread among Wolbachia. Here, we investigate whether a parthenogenesis-inducing Wolbachia strain can also induce CI. Parthenogenetic females of the parasitoid wasp Asobara japonica regularly produce a small number of males that may be either infected or not. Uninfected males were further obtained through removal of the Wolbachia using antibiotics and from a naturally uninfected strain. Uninfected females that had mated with infected males produced a slightly, but significantly more male-biased sex ratio than uninfected females that had mated with uninfected males. This effect was strongest in females that mated with males that had a relatively high Wolbachia titer. Quantitative PCR indicated that infected males did not show higher ratios of nuclear versus mitochondrial DNA content. Wolbachia therefore does not cause diploidization of cells in infected males. While these results are consistent with CI, other alternatives such as production of abnormal sperm by infected males cannot be completely ruled out. Overall, the effect was very small (9%), suggesting that if CI is involved it may have degenerated through the accumulation of mutations.

  2. Fluid injection and induced seismicity

    NASA Astrophysics Data System (ADS)

    Kendall, Michael; Verdon, James

    2016-04-01

    The link between fluid injection, or extraction, and induced seismicity has been observed in reservoirs for many decades. In fact spatial mapping of low magnitude events is routinely used to estimate a stimulated reservoir volume. However, the link between subsurface fluid injection and larger felt seismicity is less clear and has attracted recent interest with a dramatic increase in earthquakes associated with the disposal of oilfield waste fluids. In a few cases, hydraulic fracturing has also been linked to induced seismicity. Much can be learned from past case-studies of induced seismicity so that we can better understand the risks posed. Here we examine 12 case examples and consider in particular controls on maximum event size, lateral event distributions, and event depths. Our results suggest that injection volume is a better control on maximum magnitude than past, natural seismicity in a region. This might, however, simply reflect the lack of baseline monitoring and/or long-term seismic records in certain regions. To address this in the UK, the British Geological Survey is leading the deployment of monitoring arrays in prospective shale gas areas in Lancashire and Yorkshire. In most cases, seismicity is generally located in close vicinity to the injection site. However, in some cases, the nearest events are up to 5km from the injection point. This gives an indication of the minimum radius of influence of such fluid injection projects. The most distant events are never more than 20km from the injection point, perhaps implying a maximum radius of influence. Some events are located in the target reservoir, but most occur below the injection depth. In fact, most events lie in the crystalline basement underlying the sedimentary rocks. This suggests that induced seismicity may not pose a leakage risk for fluid migration back to the surface, as it does not impact caprock integrity. A useful application for microseismic data is to try and forecast induced seismicity

  3. Toxin-induced hepatic injury.

    PubMed

    Lopez, Annette M; Hendrickson, Robert G

    2014-02-01

    Toxins such as pharmaceuticals, herbals, foods, and supplements may lead to hepatic damage. This damage may range from nonspecific symptoms in the setting of liver test abnormalities to acute hepatic failure. The majority of severe cases of toxin-induced hepatic injury are caused by acetaminophen and ethanol. The most important step in the patient evaluation is to gather an extensive history that includes toxin exposure and exclude common causes of liver dysfunction. Patients whose hepatic dysfunction progresses to acute liver failure may benefit from transfer to a transplant service for further management. Currently, the mainstay in management for most exposures is discontinuing the offending agent. This manuscript will review the incidence, pathophysiology, diagnosis and management of the different forms of toxin-induced hepatic injury and exam in-depth the most common hepatic toxins.

  4. Disorder induced Floquet Topological Insulators

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Paraj; Lindner, Netanel; Rechtsman, Mikael; Refael, Gil

    2014-03-01

    We investigate the possibility of realizing a disorder induced topological state in two dimensional periodically driven systems. This phenomenon is akin to the topological Anderson insulator (TAI) in equilibrium systems. We focus on graphene band structures, where in the presence of the driving electromagnetic field, but in the absence of disorder, the system starts off in a trivial state due to the presence of a sublattice potential. We show that by adding on-site disorder a topological state is induced in this system. We numerically compute the average Bott index (the analog of the Chern number for disordered systems) to show that starting from a trivial phase, topological behavior can be observed at finite disorder strength. In the topological phase, we detect chiral edge states by a numerical time evolution of wavepackets at the edge of the system. We propose an experimental set-up in photonic lattices to observe this phenomenon.

  5. Aloe-induced Toxic Hepatitis

    PubMed Central

    Yang, Ha Na; Kim, Young Mook; Kim, Byoung Ho; Sohn, Kyoung Min; Choi, Myung Jin; Choi, Young Hee

    2010-01-01

    Aloe has been widely used in phytomedicine. Phytomedicine describes aloe as a herb which has anti-inflammatory, anti-proliferative, anti-aging effects. In recent years several cases of aloe-induced hepatotoxicity were reported. But its pharmacokinetics and toxicity are poorly described in the literature. Here we report three cases with aloe-induced toxic hepatitis. A 57-yr-old woman, a 62-yr-old woman and a 55-yr-old woman were admitted to the hospital for acute hepatitis. They had taken aloe preparation for months. Their clinical manifestation, laboratory findings and histologic findings met diagnostic criteria (RUCAM scale) of toxic hepatitis. Upon discontinuation of the oral aloe preparations, liver enzymes returned to normal level. Aloe should be considered as a causative agent in hepatotoxicity. PMID:20191055

  6. Drug-induced Liver Injury

    PubMed Central

    David, Stefan; Hamilton, James P

    2011-01-01

    Drug-induced liver injury (DILI) is common and nearly all classes of medications can cause liver disease. Most cases of DILI are benign, and improve after drug withdrawal. It is important to recognize and remove the offending agent as quickly as possible to prevent the progression to chronic liver disease and/or acute liver failure. There are no definite risk factors for DILI, but pre-existing liver disease and genetic susceptibility may predispose certain individuals. Although most patients have clinical symptoms that are identical to other liver diseases, some patients may present with symptoms of systemic hypersensitivity. Treatment of drug and herbal-induced liver injury consists of rapid drug discontinuation and supportive care targeted to alleviate unwanted symptoms. PMID:21874146

  7. Abacavir-induced liver toxicity.

    PubMed

    Pezzani, Maria Diletta; Resnati, Chiara; Di Cristo, Valentina; Riva, Agostino; Gervasoni, Cristina

    2016-01-01

    Abacavir-induced liver toxicity is a rare event almost exclusively occurring in HLA B*5701-positive patients. Herein, we report one case of abnormal liver function tests occurring in a young HLA B*5701-negative woman on a stable nevirapine-based regimen with no history of liver problems or alcohol abuse after switching to abacavir from tenofovir. We also investigated the reasons for abacavir discontinuation in a cohort of patients treated with abacavir-lamivudine-nevirapine.

  8. Cadmium-induced testicular injury

    SciTech Connect

    Siu, Erica R.; Mruk, Dolores D.; Porto, Catarina S.; Cheng, C. Yan

    2009-08-01

    Cadmium (Cd) is an environmental toxicant and an endocrine disruptor in humans and rodents. Several organs (e.g., kidney, liver) are affected by Cd and recent studies have illustrated that the testis is exceedingly sensitive to Cd toxicity. More important, Cd and other toxicants, such as heavy metals (e.g., lead, mercury) and estrogenic-based compounds (e.g., bisphenols) may account for the recent declining fertility in men among developed countries by reducing sperm count and testis function. In this review, we critically discuss recent data in the field that have demonstrated the Cd-induced toxicity to the testis is probably the result of interactions of a complex network of causes. This is likely to involve the disruption of the blood-testis barrier (BTB) via specific signal transduction pathways and signaling molecules, such as p38 mitogen-activated protein kinase (MAPK). We also summarize current studies on factors that confer and/or regulate the testis sensitivity to Cd, such as Cd transporters and metallothioneins, the impact of Cd on the testis as an endocrine disruptor and oxidative stress inducer, and how it may disrupt the Zn{sup 2+} and/or Ca{sup 2+} mediated cellular events. While much work is needed before a unified mechanistic pathway of Cd-induced testicular toxicity emerges, recent studies have helped to identify some of the likely mechanisms and/or events that take place during Cd-induced testis injury. Furthermore, some of the recent studies have shed lights on potential therapeutic or preventive approaches that can be developed in future studies by blocking or minimizing the destructive effects of Cd to testicular function in men.

  9. The fluctuation induced Hall effect

    SciTech Connect

    Shen, W.; Prager, S.C.

    1993-02-01

    The fluctuation induced Hall term, {le}{approximately}{ovr J} {times} {approximately}{ovr B}{ge}, has been measured in the MST reversed field pinch. The term is of interest as a possible source of current self-generation (dynamo). It is found to be non-negligible, but small in that it can account for less than 25% of the dynamo driven current.

  10. The fluctuation induced Hall effect

    SciTech Connect

    Shen, W.; Prager, S.C.

    1993-02-01

    The fluctuation induced Hall term, [le][approximately][ovr J] [times] [approximately][ovr B][ge], has been measured in the MST reversed field pinch. The term is of interest as a possible source of current self-generation (dynamo). It is found to be non-negligible, but small in that it can account for less than 25% of the dynamo driven current.

  11. Etanercept-induced cystic acne.

    PubMed

    Kashat, Maria; Caretti, Katherine; Kado, Jessica

    2014-07-01

    Tumor necrosis factor α antagonists are potent biologics used to treat a variety of autoimmune disorders such as rheumatoid arthritis, ankylosing spondylitis, Crohn disease, psoriasis, and psoriatic arthritis. These medications are known to have many side effects (eg, infusion reactions, cytopenia, risk for infection, heart failure); however, only a few cases of acne vulgaris have been associated with the use of these biologics, particularly infliximab and adalimumab. We report a rare case of etanercept-induced cystic acne.

  12. Nanostructure-induced DNA condensation

    NASA Astrophysics Data System (ADS)

    Zhou, Ting; Llizo, Axel; Wang, Chen; Xu, Guiying; Yang, Yanlian

    2013-08-01

    The control of the DNA condensation process is essential for compaction of DNA in chromatin, as well as for biological applications such as nonviral gene therapy. This review endeavours to reflect the progress of investigations on DNA condensation effects of nanostructure-based condensing agents (such as nanoparticles, nanotubes, cationic polymer and peptide agents) observed by using atomic force microscopy (AFM) and other techniques. The environmental effects on structural characteristics of nanostructure-induced DNA condensates are also discussed.

  13. Cadmium-induced Testicular Injury*

    PubMed Central

    Siu, Erica R.; Mruk, Dolores D.; Porto, Catarina S.; Cheng, C. Yan

    2009-01-01

    Cadmium (Cd) is an environmental toxicant and an endocrine disruptor in humans. Several organs (e.g., kidney, liver) are affected by Cd and recent studies have illustrated that the testis is exceedingly sensitive to Cd toxicity. More important, Cd and other toxicants, such as heavy metals (e.g., lead, mercury) and estrogenic-based compounds (e.g., bisphenols) may account for the recent declining fertility in men among developed countries by reducing sperm count and testis function. In this review, we critically discuss recent data in the field that have demonstrated the Cd-induced toxicity to the testis is probably the result of interactions of a complex network of causes. This is likely to involve the disruption of the blood-testis barrier (BTB) via specific signal transduction pathways and signaling molecules, such as p38 mitogen-activated protein kinase (MAPK). We also summarize current studies on factors that confer the testis sensitivity to Cd, such as Cd transporters and metallothioneins, and the impact of Cd on the testis as an endocrine disruptor, oxidative stress inducer and how it may disrupt the Zn+2 and/or Ca+2 mediated cellular events. While much work is needed before a unified mechanistic pathway of Cd-induced testicular toxicity is emerged, recent studies have helped to identify some of the likely mechanisms and/or events that take place during Cd-induced testis injury. Furthermore, some of the recent studies have shed lights on potential therapeutic or preventive approaches that can be developed in future studies by blocking or minimizing the destructive effects of Cd to testicular function in men. PMID:19236889

  14. Propulsion Induced Effects Test Program

    NASA Technical Reports Server (NTRS)

    Cappuccio, Gelsomina; Won, Mark; Bencze, Dan

    1999-01-01

    The objective of this milestone is to assess the propulsion/airframe integration characteristics of the Technology Concept Airplane and design variations through computational analysis and experimental subsonic through supersonic wind tunnel testing. The Milestone will generate a comprehensive CFD and wind tunnel data base of the baseline, and design variations. Emphasis will be placed on establishing the propulsion induced effects on the flight performance of the Technology Concept Airplane with all appropriate wind tunnel corrections.

  15. Acyclovir-induced thrombotic microangiopathy

    PubMed Central

    Goli, R.; Mukku, K. K.; Devaraju, S. B. R.; Uppin, M. S.

    2017-01-01

    Acyclovir is a commonly used antiviral drug. Acute kidney injury (AKI) due to intratubular crystal precipitation and interstitial nephritis is well known. Here we present a case of acyclovir induced AKI in a 61 year old male with herpes zoster, which presented like thrombotic microangiopathy with acute interstitial nephritis. This is the first case report on acyclovir causing thrombotic microaniopathy with partial improvement in renal function after plasmapharesis. PMID:28356666

  16. Drug-Induced Sleep Endoscopy.

    PubMed

    Charakorn, Natamon; Kezirian, Eric J

    2016-12-01

    Drug-induced sleep endoscopy (DISE) is an upper airway evaluation technique in which fiberoptic examination is performed under conditions of unconscious sedation. Unique information obtained from this 3-dimensional examination of the airway potentially provides additive benefits to other evaluation methods to guide treatment selection. This article presents recommendations regarding DISE technique and the VOTE Classification system for reporting DISE findings and reviews the evidence concerning DISE test characteristics and the association between DISE findings and treatment outcomes.

  17. Local Anesthetic-Induced Neurotoxicity

    PubMed Central

    Verlinde, Mark; Hollmann, Markus W.; Stevens, Markus F.; Hermanns, Henning; Werdehausen, Robert; Lirk, Philipp

    2016-01-01

    This review summarizes current knowledge concerning incidence, risk factors, and mechanisms of perioperative nerve injury, with focus on local anesthetic-induced neurotoxicity. Perioperative nerve injury is a complex phenomenon and can be caused by a number of clinical factors. Anesthetic risk factors for perioperative nerve injury include regional block technique, patient risk factors, and local anesthetic-induced neurotoxicity. Surgery can lead to nerve damage by use of tourniquets or by direct mechanical stress on nerves, such as traction, transection, compression, contusion, ischemia, and stretching. Current literature suggests that the majority of perioperative nerve injuries are unrelated to regional anesthesia. Besides the blockade of sodium channels which is responsible for the anesthetic effect, systemic local anesthetics can have a positive influence on the inflammatory response and the hemostatic system in the perioperative period. However, next to these beneficial effects, local anesthetics exhibit time and dose-dependent toxicity to a variety of tissues, including nerves. There is equivocal experimental evidence that the toxicity varies among local anesthetics. Even though the precise order of events during local anesthetic-induced neurotoxicity is not clear, possible cellular mechanisms have been identified. These include the intrinsic caspase-pathway, PI3K-pathway, and MAPK-pathways. Further research will need to determine whether these pathways are non-specifically activated by local anesthetics, or whether there is a single common precipitating factor. PMID:26959012

  18. Chemotherapy-induced peripheral neuropathy.

    PubMed

    Fehrenbacher, Jill C

    2015-01-01

    Chemotherapy-induced peripheral neuropathy (CIPN) is common in patients receiving anticancer treatment and can affect survivability and long-term quality of life of the patient following treatment. The symptoms of CIPN primarily include abnormal sensory discrimination of touch, vibration, thermal information, and pain. There is currently a paucity of pharmacological agents to prevent or treat CIPN. The lack of efficacious therapeutics is due, at least in part, to an incomplete understanding of the mechanisms by which chemotherapies alter the sensitivity of sensory neurons. Although the clinical presentation of CIPN can be similar with the various classes of chemotherapeutic agents, there are subtle differences, suggesting that each class of drugs might induce neuropathy via different mechanisms. Multiple mechanisms have been proposed to underlie the development and maintenance of neuropathy; however, most pharmacological agents generated from preclinical experiments have failed to alleviate the symptoms of CIPN in the clinic. Further research is necessary to identify the specific mechanisms by which each class of chemotherapeutics induces neuropathy.

  19. Induced radioactivity in LDEF components

    NASA Technical Reports Server (NTRS)

    Harmon, B. A.; Fishman, G. J.; Parnell, T. A.; Laird, C. E.

    1991-01-01

    The systematics of induced radioactivity on the Long Duration Exposure Facility (LDEF) were studied in a wide range of materials using low level background facilities for detection of gamma rays. Approx. 400 samples of materials processed from structural parts of the spacecraft, as well as materials from onboard experiments, were analyzed at national facilities. These measurements show the variety of radioisotopes that are produced with half-lives greater than 2 wks, most of which are characteristic of proton induced reactions above 20 MeV. For the higher activity, long lived isotopes, it was possible to map the depth and directional dependences of the activity. Due to the stabilized configuration of the LDEF, the induced radioactivity data clearly show contributions from the anisotropic trapped proton flux in the South Atlantic Anomaly. This effect is discussed, along with evidence for activation by galactic protons and thermal neutrons. The discovery of Be-7 was made on leading side parts of the spacecraft, although this was though not to be related to the in situ production of radioisotopes from external particle fluxes.

  20. [Drug-induced oral ulcerations].

    PubMed

    Madinier, I; Berry, N; Chichmanian, R M

    2000-06-01

    Different side effects of drugs have been described in the oral cavity, including oral ulcerations. Direct contact between drugs and oral mucosa may induce chemical burn or local hypersensitivity. Less frequently, these drug-induced oral ulcerations are part of a complex reaction with cutaneous or systemic manifestations. Sometimes, one or more oral ulcerations appear as the main side-effect of a drug, or exceptionally as solitary lesions. Solitary oral ulcerations usually appear after few weeks of treatment. In most of cases, these lesions resist to conventional treatments, with a rapid healing following the suppression of the responsible drug. This diagnosis is usually difficult, particularly with patients receiving multiple drug therapy. Besides, special attention must be paid to new drugs. Oral ulcerations following symptoms of burning mouth, metallic taste, dysgueusia or agueusia are strongly suggestive of a pharmacological origin. Most of the molecules able to induce solitary oral ulcerations are commonly prescribed in a) rheumatology: NSAI (diclofenac, flurbiprofen, indomethacin, naproxen), long-term rheumatoid arthritis therapy (azathioprine, methotrexate, penicillamine, gold compounds, tiopronin); b) cardiology: angiotensin-converting-enzyme inhibitors (captopril, enalapril), angiotensin 2-receptor antagonist (losartan), anti-angorous (nicorandil), c) psychiatry: antidepressants (fluoxetine, lithium), d) AIDS therapy (foscarnet, zalcitabine).

  1. Efficient treatment of induced dipoles

    PubMed Central

    Simmonett, Andrew C.; Pickard, Frank C.; Shao, Yihan; Cheatham, Thomas E.; Brooks, Bernard R.

    2015-01-01

    Most existing treatments of induced dipoles in polarizable molecular mechanics force field calculations use either the self-consistent variational method, which is solved iteratively, or the “direct” approximation that is non-iterative as a result of neglecting coupling between induced dipoles. The variational method is usually implemented using assumptions that are only strictly valid under tight convergence of the induced dipoles, which can be computationally demanding to enforce. In this work, we discuss the nature of the errors that result from insufficient convergence and suggest a strategy that avoids such problems. Using perturbation theory to reintroduce the mutual coupling into the direct algorithm, we present a computationally efficient method that combines the precision of the direct approach with the accuracy of the variational approach. By analyzing the convergence of this perturbation series, we derive a simple extrapolation formula that delivers a very accurate approximation to the infinite order solution at the cost of only a few iterations. We refer to the new method as extrapolated perturbation theory. Finally, we draw connections to our previously published permanent multipole algorithm to develop an efficient implementation of the electric field and Thole terms and also derive some necessary, but not sufficient, criteria that force field parameters must obey. PMID:26298123

  2. Chromium-induced kidney disease

    SciTech Connect

    Wedeen, R.P. ); Qian, Lifen )

    1991-05-01

    Kidney disease is often cited as one of the adverse effects of chromium, yet chronic renal disease due to occupational or environmental exposure to chromium has not been reported. Occasional cases of acute tubular necrosis (ATN) following massive absorption of chromate have been described. Chromate-induced ATN has been extensively studied in experimental animals following parenteral administration of large doses of potassium chromate (hexavalent). The chromate is selectively accumulated in the convoluted proximal tubule where necrosis occurs. An adverse long-term effect of low-dose chromium exposure on the kidneys is suggested by reports of low molecular weight (LMW) proteinuria in chromium workers. Excessive urinary excretion of {beta}{sub 2}-microglobulin, a specific proximal tubule brush border protein, and retinol-binding protein has been reported among chrome palters and welders. However, LMW proteinuria occurs after a variety of physiologic stresses, is usually reversible, and cannot by itself be considered evidence of chromic renal disease. Chromate-induced ATN and LMW proteinuria in chromium workers, nevertheless, raise the possibility that low-level, long-term exposure may produce persistent renal injury. The absence of evidence of chromate-induced chromic renal disease cannot be interpreted as evidence of the absence of such injury.

  3. Field induced gap infrared detector

    NASA Technical Reports Server (NTRS)

    Elliott, C. Thomas (Inventor)

    1990-01-01

    A tunable infrared detector which employs a vanishing band gap semimetal material provided with an induced band gap by a magnetic field to allow intrinsic semiconductor type infrared detection capabilities is disclosed. The semimetal material may thus operate as a semiconductor type detector with a wavelength sensitivity corresponding to the induced band gap in a preferred embodiment of a diode structure. Preferred semimetal materials include Hg(1-x)Cd(x)Te, x is less than 0.15, HgCdSe, BiSb, alpha-Sn, HgMgTe, HgMnTe, HgZnTe, HgMnSe, HgMgSe, and HgZnSe. The magnetic field induces a band gap in the semimetal material proportional to the strength of the magnetic field allowing tunable detection cutoff wavelengths. For an applied magnetic field from 5 to 10 tesla, the wavelength detection cutoff will be in the range of 20 to 50 micrometers for Hg(1-x)Cd(x)Te alloys with x about 0.15. A similar approach may also be employed to generate infrared energy in a desired band gap and then operating the structure in a light emitting diode or semiconductor laser type of configuration.

  4. Statistical Seismology and Induced Seismicity

    NASA Astrophysics Data System (ADS)

    Tiampo, K. F.; González, P. J.; Kazemian, J.

    2014-12-01

    While seismicity triggered or induced by natural resources production such as mining or water impoundment in large dams has long been recognized, the recent increase in the unconventional production of oil and gas has been linked to rapid rise in seismicity in many places, including central North America (Ellsworth et al., 2012; Ellsworth, 2013). Worldwide, induced events of M~5 have occurred and, although rare, have resulted in both damage and public concern (Horton, 2012; Keranen et al., 2013). In addition, over the past twenty years, the increase in both number and coverage of seismic stations has resulted in an unprecedented ability to precisely record the magnitude and location of large numbers of small magnitude events. The increase in the number and type of seismic sequences available for detailed study has revealed differences in their statistics that previously difficult to quantify. For example, seismic swarms that produce significant numbers of foreshocks as well as aftershocks have been observed in different tectonic settings, including California, Iceland, and the East Pacific Rise (McGuire et al., 2005; Shearer, 2012; Kazemian et al., 2014). Similarly, smaller events have been observed prior to larger induced events in several occurrences from energy production. The field of statistical seismology has long focused on the question of triggering and the mechanisms responsible (Stein et al., 1992; Hill et al., 1993; Steacy et al., 2005; Parsons, 2005; Main et al., 2006). For example, in most cases the associated stress perturbations are much smaller than the earthquake stress drop, suggesting an inherent sensitivity to relatively small stress changes (Nalbant et al., 2005). Induced seismicity provides the opportunity to investigate triggering and, in particular, the differences between long- and short-range triggering. Here we investigate the statistics of induced seismicity sequences from around the world, including central North America and Spain, and

  5. Ion beam induced luminescence: Relevance to radiation induced bystander effects

    NASA Astrophysics Data System (ADS)

    Ahmad, S. B.; McNeill, F. E.; Byun, S. H.; Prestwich, W. V.; Seymour, C.; Mothersill, C. E.

    2012-10-01

    The aim of this work is quantify the light emitted as a result of charged particle interaction in materials which may be of relevance to radiation induced "bystander effects" studies. We have developed a system which employs single photon counting to measure the light emitted from samples irradiated under vacuum by a charged particle beam. The system uses a fast photomultiplier tube with a peak cathode response at 420 nm. It has been tested in a proof-of-principle experiment using polystyrene targets. Light output, as a result of irradiation, was measured. The luminescence yield appears to have a non-linear behavior with the incident ion fluence: it rises exponentially to an asymptotic value. The target was irradiated with beam energies varying from 1 to 2 MeV and showed saturation at or before an incident fluence rate of 3 × 1013 H+/cm2 s. The average saturation value for the photon output was found to be 40 × 106 cps. Some measurements were performed using filters to study the emission at specific wavelengths. In the case of filtered light measurements, the photon output was found to saturate at 28 × 103, 10 × 106, and 35 × 106 cps for wavelengths of 280 ± 5 nm, 320 ± 5 nm and 340 ± 5 nm respectively. The light output reaches a maximum value because of damage induced in the polymer. Our measurements indicate a "damage cross section" of the order of 10-14 cm2. The average radiant intensity was found to increase at wavelengths of 280 and 320 nm when the proton energy was increased. This was not found to occur at 340 nm. In conclusion, the light emission at specific wavelengths was found to depend upon the incident proton fluence and the proton energy. The wavelengths of the emitted light measured in this study have significance for the understanding of radiation induced bystander effects.

  6. Homocysteine induces inflammatory transcriptional signaling in monocytes.

    PubMed

    Meng, Shu; Ciment, Stephen; Jan, Michael; Tran, Tran; Pham, Hung; Cueto, Ramon; Yang, Xiao-Feng; Wang, Hong

    2013-01-01

    Hyperhomocysteinemia (HHcy) is an independent risk factor for cardiovascular disease. Here, we studied transcriptional regulation in homocysteine (Hcy)-induced gene expression in monocytes (MC). We identified 11 Hcy-induced genes, 17 anti-inflammatory cytokine interleukin 10-induced, 8 pro-inflammatory cytokine interferon gamma (IFN gamma)-induced and 8 pro-inflammatory cytokine tumor necrosis factor alpha (TNF alpha)-induced genes through literature search. Binding frequency of 36 transcription factors (TFs) implicated in inflammation and MC differentiation were analyzed within core promoter regions of identified genes, and classified into 3 classes based on the significant binding frequency to the promoter of Hcy-induced genes. Class 1 TFs exert high significant binding frequency in Hcy-induced genes. Class 2 and 3 TFs have low and no significant binding frequency, respectively. Class 1 TF binding occurrence in Hcy-induced genes is similar to that in IFN gamma -induced genes, but not that in TNF alpha -induced. We conclude that Hcy is a pro-inflammatory amino acid and induces inflammatory transcriptional signal pathways mediated by class 1 TF. We term class 1 TF as putative Hcy-responsive TFs.

  7. Homocysteine induces inflammatory transcriptional signaling in monocytes

    PubMed Central

    Meng, Shu; Ciment, Stephen; Jan, Michael; Tran, Tran; Pham, Hung; Cueto, Ramón; Yang, Xiao-Feng; Wang, Hong

    2013-01-01

    Hyperhomocysteinemia (HHcy) is an independent risk factor for cardiovascular disease. This study is to investigate transcriptional mechanism underlying homocysteine (Hcy)-induced and monocytes (MC)-derived inflammatory response. We identified 11 Hcy-induced genes, 17 anti-inflammatory cytokine interleukin 10-induced, 8 pro-inflammatory cytokine interferon γ (IFNγ)-induced and 8 pro-inflammatory cytokine tumor necrosis factor α (TNFα)-induced genes through literature search. Binding frequency of 36 transcription factors (TFs) implicated in inflammation and MC differentiation were analyzed within core promoter regions of identified genes, and classified into 3 classes based on the significant binding frequency to the promoter of Hcy-induced genes. Class 1 TFs exert high significant binding frequency in Hcy-induced genes. Class 2 and 3 TFs have low and no significant binding frequency, respectively. Class 1 TF binding occurrence in Hcy-induced genes is similar to that in IFNγ-induced genes, but not that in TNFα-induced. We conclude that Hcy is a pro-inflammatory amino acid and induces inflammatory transcriptional signal pathways mediated by class 1 TF. We term class 1 TF, which includes heat shock factor, MC enhancer factor-2, nuclear factor of activated T-cells, nuclear factor kappa light chain enhancer of activated B cells and Krueppel-like factor 4, as putative Hcy-responsive TFs. PMID:23276953

  8. High homocysteine induces betaine depletion

    PubMed Central

    Imbard, Apolline; Benoist, Jean-François; Esse, Ruben; Gupta, Sapna; Lebon, Sophie; de Vriese, An S; de Baulny, Helene Ogier; Kruger, Warren; Schiff, Manuel; Blom, Henk J.

    2015-01-01

    Betaine is the substrate of the liver- and kidney-specific betaine-homocysteine (Hcy) methyltransferase (BHMT), an alternate pathway for Hcy remethylation. We hypothesized that BHMT is a major pathway for homocysteine removal in cases of hyperhomocysteinaemia (HHcy). Therefore, we measured betaine in plasma and tissues from patients and animal models of HHcy of genetic and acquired cause. Plasma was collected from patients presenting HHcy without any Hcy interfering treatment. Plasma and tissues were collected from rat models of HHcy induced by diet and from a mouse model of cystathionine β-synthase (CBS) deficiency. S-adenosyl-methionine (AdoMet), S-adenosyl-homocysteine (AdoHcy), methionine, betaine and dimethylglycine (DMG) were quantified by ESI—LC–MS/MS. mRNA expression was quantified using quantitative real-time (QRT)-PCR. For all patients with diverse causes of HHcy, plasma betaine concentrations were below the normal values of our laboratory. In the diet-induced HHcy rat model, betaine was decreased in all tissues analysed (liver, brain, heart). In the mouse CBS deficiency model, betaine was decreased in plasma, liver, heart and brain, but was conserved in kidney. Surprisingly, BHMT expression and activity was decreased in liver. However, in kidney, BHMT and SLC6A12 expression was increased in CBS-deficient mice. Chronic HHcy, irrespective of its cause, induces betaine depletion in plasma and tissues (liver, brain and heart), indicating a global decrease in the body betaine pool. In kidney, betaine concentrations were not affected, possibly due to overexpression of the betaine transporter SLC6A12 where betaine may be conserved because of its crucial role as an osmolyte. PMID:26182429

  9. High homocysteine induces betaine depletion.

    PubMed

    Imbard, Apolline; Benoist, Jean-François; Esse, Ruben; Gupta, Sapna; Lebon, Sophie; de Vriese, An S; de Baulny, Helene Ogier; Kruger, Warren; Schiff, Manuel; Blom, Henk J

    2015-04-28

    Betaine is the substrate of the liver- and kidney-specific betaine-homocysteine (Hcy) methyltransferase (BHMT), an alternate pathway for Hcy remethylation. We hypothesized that BHMT is a major pathway for homocysteine removal in cases of hyperhomocysteinaemia (HHcy). Therefore, we measured betaine in plasma and tissues from patients and animal models of HHcy of genetic and acquired cause. Plasma was collected from patients presenting HHcy without any Hcy interfering treatment. Plasma and tissues were collected from rat models of HHcy induced by diet and from a mouse model of cystathionine β-synthase (CBS) deficiency. S-adenosyl-methionine (AdoMet), S-adenosyl-homocysteine (AdoHcy), methionine, betaine and dimethylglycine (DMG) were quantified by ESI-LC-MS/MS. mRNA expression was quantified using quantitative real-time (QRT)-PCR. For all patients with diverse causes of HHcy, plasma betaine concentrations were below the normal values of our laboratory. In the diet-induced HHcy rat model, betaine was decreased in all tissues analysed (liver, brain, heart). In the mouse CBS deficiency model, betaine was decreased in plasma, liver, heart and brain, but was conserved in kidney. Surprisingly, BHMT expression and activity was decreased in liver. However, in kidney, BHMT and SLC6A12 expression was increased in CBS-deficient mice. Chronic HHcy, irrespective of its cause, induces betaine depletion in plasma and tissues (liver, brain and heart), indicating a global decrease in the body betaine pool. In kidney, betaine concentrations were not affected, possibly due to overexpression of the betaine transporter SLC6A12 where betaine may be conserved because of its crucial role as an osmolyte.

  10. Vibrational excitation induces double reaction.

    PubMed

    Huang, Kai; Leung, Lydie; Lim, Tingbin; Ning, Zhanyu; Polanyi, John C

    2014-12-23

    Electron-induced reaction at metal surfaces is currently the subject of extensive study. Here, we broaden the range of experimentation to a comparison of vibrational excitation with electronic excitation, for reaction of the same molecule at the same clean metal surface. In a previous study of electron-induced reaction by scanning tunneling microscopy (STM), we examined the dynamics of the concurrent breaking of the two C-I bonds of ortho-diiodobenzene physisorbed on Cu(110). The energy of the incident electron was near the electronic excitation threshold of E0=1.0 eV required to induce this single-electron process. STM has been employed in the present work to study the reaction dynamics at the substantially lower incident electron energies of 0.3 eV, well below the electronic excitation threshold. The observed increase in reaction rate with current was found to be fourth-order, indicative of multistep reagent vibrational excitation, in contrast to the first-order rate dependence found earlier for electronic excitation. The change in mode of excitation was accompanied by altered reaction dynamics, evidenced by a different pattern of binding of the chemisorbed products to the copper surface. We have modeled these altered reaction dynamics by exciting normal modes of vibration that distort the C-I bonds of the physisorbed reagent. Using the same ab initio ground potential-energy surface as in the prior work on electronic excitation, but with only vibrational excitation of the physisorbed reagent in the asymmetric stretch mode of C-I bonds, we obtained the observed alteration in reaction dynamics.

  11. Sad music induces pleasant emotion.

    PubMed

    Kawakami, Ai; Furukawa, Kiyoshi; Katahira, Kentaro; Okanoya, Kazuo

    2013-01-01

    In general, sad music is thought to cause us to experience sadness, which is considered an unpleasant emotion. As a result, the question arises as to why we listen to sad music if it evokes sadness. One possible answer to this question is that we may actually feel positive emotions when we listen to sad music. This suggestion may appear to be counterintuitive; however, in this study, by dividing musical emotion into perceived emotion and felt emotion, we investigated this potential emotional response to music. We hypothesized that felt and perceived emotion may not actually coincide in this respect: sad music would be perceived as sad, but the experience of listening to sad music would evoke positive emotions. A total of 44 participants listened to musical excerpts and provided data on perceived and felt emotions by rating 62 descriptive words or phrases related to emotions on a scale that ranged from 0 (not at all) to 4 (very much). The results revealed that the sad music was perceived to be more tragic, whereas the actual experiences of the participants listening to the sad music induced them to feel more romantic, more blithe, and less tragic emotions than they actually perceived with respect to the same music. Thus, the participants experienced ambivalent emotions when they listened to the sad music. After considering the possible reasons that listeners were induced to experience emotional ambivalence by the sad music, we concluded that the formulation of a new model would be essential for examining the emotions induced by music and that this new model must entertain the possibility that what we experience when listening to music is vicarious emotion.

  12. Metabolic Stress Induced by Arginine Deprivation Induces Autophagy Cell Death in Prostate Cancer

    DTIC Science & Technology

    2010-08-01

    Arginine deiminase as a novel therapy for prostate cancer induces autophagy and caspase-independent apoptosis. Cancer Research, 69(2):700-708...TITLE: Metabolic stress induced by arginine deprivation induces autophagy cell death in prostate cancer PRINCIPAL INVESTIGATOR: Richard Bold, MD...4. TITLE AND SUBTITLE Metabolic stress induced by arginine deprivation induces autophagy cell 5a. CONTRACT NUMBER death in prostate cancer 5b

  13. Kif2a depletion generates chromosome segregation and pole coalescence defects in animal caps and inhibits gastrulation of the Xenopus embryo

    PubMed Central

    Eagleson, Gerald; Pfister, Katherine; Knowlton, Anne L.; Skoglund, Paul; Keller, Ray; Stukenberg, P. Todd

    2015-01-01

    Kif2a is a member of the kinesin-13 microtubule depolymerases, which tightly regulate microtubule dynamics for many cellular processes. We characterized Kif2a depletion in Xenopus animal caps and embryos. Kif2a depletion generates defects in blastopore closure. These defects are rescued by removing the animal cap, suggesting that Kif2a-depleted animal caps are not compliant enough to allow gastrulation movements. Gastrulation defects are not rescued by a Kif2a mutated in an Aurora kinase phosphorylation site, suggesting that the phenotypes are caused by problems in mitosis. During animal cap mitoses, Kif2a localizes to the spindle poles and centromeres. Depletion of Kif2a generated multipolar spindles in stage 12 embryos. Kif2a-depleted animal caps have anaphase lagging chromosomes in stage 9 and 10 embryos and subsequent cytokinesis failure. Later divisions have greater than two centrosomes, generating extra spindle poles. Kif2a-depleted embryos are also defective at coalescing extra spindle poles into a bipolar spindle. The gastrulation and mitotic phenotypes can be rescued by either human Kif2a or Kif2b, which suggests that the two homologues redundantly regulate mitosis in mammals. These studies demonstrate that defects in mitosis can inhibit large-scale developmental movements in vertebrate tissues. PMID:25568341

  14. The ploidy conveyor of mature hepatocytes as a source of genetic variation.

    PubMed

    Duncan, Andrew W; Taylor, Matthew H; Hickey, Raymond D; Hanlon Newell, Amy E; Lenzi, Michelle L; Olson, Susan B; Finegold, Milton J; Grompe, Markus

    2010-10-07

    Mononucleated and binucleated polyploid hepatocytes (4n, 8n, 16n and higher) are found in all mammalian species, but the functional significance of this conserved phenomenon remains unknown. Polyploidization occurs through failed cytokinesis, begins at weaning in rodents and increases with age. Previously, we demonstrated that the opposite event, ploidy reversal, also occurs in polyploid hepatocytes generated by artificial cell fusion. This raised the possibility that somatic 'reductive mitoses' can also happen in normal hepatocytes. Here we show that multipolar mitotic spindles form frequently in mouse polyploid hepatocytes and can result in one-step ploidy reversal to generate offspring with halved chromosome content. Proliferating hepatocytes produce a highly diverse population of daughter cells with multiple numerical chromosome imbalances as well as uniparental origins. Our findings support a dynamic model of hepatocyte polyploidization, ploidy reversal and aneuploidy, a phenomenon that we term the 'ploidy conveyor'. We propose that this mechanism evolved to generate genetic diversity and permits adaptation of hepatocytes to xenobiotic or nutritional injury.

  15. Spallation-induced fission reactions

    NASA Astrophysics Data System (ADS)

    Benlliure, J.; Rodríguez-Sánchez, J. L.

    2017-03-01

    During the last decade spallation-induced fission reactions have received particular attention because of their impact in the design of spallation-neutron sources or radioactive beam facilities, but also in the understanding of the fission process at high excitation energy. In this paper, we review the main progress brought by modern experimental techniques, in particular those based in the inverse kinematic, as well as the achievements in modelling these reactions. We will also address future possibilities for improving the investigation of fission dynamics.

  16. Sertraline-induced ventricular tachycardia.

    PubMed

    Patel, Nishit H; Golwala, Harsh; Stavrakis, Stavros; Schechter, Eliot

    2013-01-01

    Sertraline is a selective serotonin reuptake inhibitor, which is a commonly used drug for major depressive disorder. Most frequently reported adverse effects of sertraline in patients receiving 50-150 mg/d are dry mouth, headache, diarrhea, nausea, vomiting, sweating, and dizziness. We hereby report one of the few cases of sertraline-induced ventricular tachycardia, which has been for the first time objectively assessed by the Naranjo scale. We therefore urge the primary care physicians and the cardiologists to keep sertraline as a possible precipitating factor for evaluation of ventricular tachycardia.

  17. Auditory hallucinations induced by trazodone.

    PubMed

    Shiotsuki, Ippei; Terao, Takeshi; Ishii, Nobuyoshi; Hatano, Koji

    2014-04-03

    A 26-year-old female outpatient presenting with a depressive state suffered from auditory hallucinations at night. Her auditory hallucinations did not respond to blonanserin or paliperidone, but partially responded to risperidone. In view of the possibility that her auditory hallucinations began after starting trazodone, trazodone was discontinued, leading to a complete resolution of her auditory hallucinations. Furthermore, even after risperidone was decreased and discontinued, her auditory hallucinations did not recur. These findings suggest that trazodone may induce auditory hallucinations in some susceptible patients.

  18. Auditory hallucinations induced by trazodone

    PubMed Central

    Shiotsuki, Ippei; Terao, Takeshi; Ishii, Nobuyoshi; Hatano, Koji

    2014-01-01

    A 26-year-old female outpatient presenting with a depressive state suffered from auditory hallucinations at night. Her auditory hallucinations did not respond to blonanserin or paliperidone, but partially responded to risperidone. In view of the possibility that her auditory hallucinations began after starting trazodone, trazodone was discontinued, leading to a complete resolution of her auditory hallucinations. Furthermore, even after risperidone was decreased and discontinued, her auditory hallucinations did not recur. These findings suggest that trazodone may induce auditory hallucinations in some susceptible patients. PMID:24700048

  19. Cocaine-induced mesenteric ischaemia.

    PubMed

    Osorio, J; Farreras, N; Ortiz De Zárate L; Bachs, E

    2000-01-01

    We report a 33-year-old man with distal ileum infarction after intravenous abuse of cocaine. He underwent resection of a gangrenous bowel segment and survived. We review the literature regarding intestinal ischaemia related to cocaine. To date, 19 cases have been published. Like most previously reported cases, our patient was young and had no previous history of arteriosclerosis. He suffered cocaine-induced rhabdomyolysis and acute renal failure. Mesenteric ischaemia should be considered in the differential diagnosis of acute or chronic abdominal pain in cocaine consumers.

  20. Fluoroquinolone-induced Achilles tendinitis.

    PubMed

    Tam, P K; Ho, Carmen T K

    2014-12-01

    We report a case of Achilles tendinitis after intake of ciprofloxacin for treatment of respiratory tract infection. Fluoroquinolone-induced tendinopathy is an uncommon but increasingly recognised adverse effect of this antibiotic class. Most of the cases occur in the Achilles tendon and may lead to tendon rupture. Possible predisposing risk factors include use of steroid, patients with renal impairment or renal transplant, old age, and being an athlete. The drug should be stopped once this condition is suspected. Symptomatic treatment should be given and orthopaedic referral is desirable if tendon rupture occurs.

  1. [Pregnancy-induced haemolytic anaemia].

    PubMed

    Karagiozova, J; Masseva, A; Ivanov, St; Marinov, B; Kulinska, R; Boiadjiev, D; Jordanova, D

    2014-01-01

    This is the clinical case of a primiparous eight month pregnant female, presenting with symptoms of pregnancy-induced acute haemolytic anaemia (haemolytic aneamia provoked by an immune mechanism, intra- and extra-erythrocyte defects, and HELLP syndrome were excluded). The anaemia progressed to become life-threatening for both the pregnant women and the foetus, which brought the following questions into consideration: diagnosis of anaemia during pregnancy; dosing of corticosteroid therapy; possibility of giving birth to a viable foetus and prognosis for next pregnancies. Owing to the inter-disciplinary efforts, the life and health of this pregnant woman were preserved, but the foetus was lost.

  2. Metronidazole-Induced Cerebellar Toxicity

    PubMed Central

    Agarwal, Amit; Kanekar, Sangam; Sabat, Shyam; Thamburaj, Krishnamurthy

    2016-01-01

    Metronidazole is a very common antibacterial and antiprotozoal with wide usage across the globe, including the least developed countries. It is generally well-tolerated with a low incidence of serious side-effects. Neurological toxicity is fairly common with this drug, however majority of these are peripheral neuropathy with very few cases of central nervous toxicity reported. We report the imaging findings in two patients with cerebellar dysfunction after Metronidazole usage. Signal changes in the dentate and red nucleus were seen on magnetic resonance imaging in these patients. Most of the cases reported in literature reported similar findings, suggesting high predilection for the dentate nucleus in metronidazole induced encephalopathy. PMID:27127600

  3. Airway management: induced tension pneumoperitoneum

    PubMed Central

    Ahmed, Khedher; Amine, El Ghali Mohamed; Abdelbaki, Azouzi; Jihene, Ayachi; Khaoula, Meddeb; Yamina, Hamdaoui; Mohamed, Boussarsar

    2016-01-01

    Pneumoperitoneum is not always associated with hollow viscus perforation. Such condition is called non-surgical or spontaneous pneumoperitoneum. Intrathoracic causes remain the most frequently reported mechanism inducing this potentially life threatening complication. This clinical condition is associated with therapeutic dilemma. We report a case of a massive isolated pneumoperitoneum causing acute abdominal hypertension syndrome, in a 75 year female, which occurred after difficult airway management and mechanical ventilation. Emergent laparotomy yielded to full recovery. The recognition of such cases for whom surgical management can be avoided is primordial to avoid unnecessary laparotomy and its associated morbidity particularly in the critically ill.

  4. HYPOGLYCEMIA INDUCED BY ANTIDIABETIC SULFONYLUREAS.

    PubMed

    Confederat, Luminiţa; Constantin, Sandra; Lupaşcu, Florentina; Pânzariu, Andreea; Hăncianu, Monica; Profire, Lenuţa

    2015-01-01

    Diabetes mellitus is a major health problem due to its increasing prevalence and life-threatening complications. Antidiabetic sulfonylureas represent the first-line drugs in type 2 diabetes even though the most common associated risk is pharmacologically-induced hypoglycemia. In the development of this side effect are involved several factors including the pharmacokinetic and pharmacodynamic profile of the drug, patient age and behavior, hepatic or renal dysfunctions, or other drugs associated with a high risk of interactions. If all these are controlled, the risk-benefit balance can be equal to other oral antidiabetic drugs.

  5. Ion-induced nuclear radiotherapy

    DOEpatents

    Horn, Kevin M.; Doyle, Barney L.

    1996-01-01

    Ion-induced Nuclear Radiotherapy (INRT) is a technique for conducting radiosurgery and radiotherapy with a very high degree of control over the spatial extent of the irradiated volume and the delivered dose. Based upon the concept that low energy, ion induced atomic and nuclear reactions can be used to produce highly energetic reaction products at the site of a tumor, the INRT technique is implemented through the use of a conduit-needle or tube which conducts a low energy ion beam to a position above or within the intended treatment area. At the end of the conduit-needle or tube is a specially fabricated target which, only when struck by the ion beam, acts as a source of energetic radiation products. The inherent limitations in the energy, and therefore range, of the resulting reaction products limits the spatial extent of irradiation to a pre-defined volume about the point of reaction. Furthermore, since no damage is done to tissue outside this irradiated volume, the delivered dose may be made arbitrarily large. INRT may be used both as a point-source of radiation at the site of a small tumor, or as a topical bath of radiation to broad areas of diseased tissue.

  6. Chemotherapy-induced hair loss.

    PubMed

    Trüeb, R M

    2010-01-01

    Chemotherapy-induced hair loss occurs with an estimated incidence of 65%. Forty-seven percent of female patients consider hair loss to be the most traumatic aspect of chemotherapy and 8% would decline chemotherapy due to fears of hair loss. At present, no approved pharmacologic intervention exists to circumvent this side-effect of anticancer treatment, though a number of agents have been investigated on the basis of the current understanding of the underlying pathobiology. Among the agents that have been evaluated, topical minoxidil was able to reduce the severity or shorten the duration, but it did not prevent hair loss. The major approach to minimize chemotherapy-induced hair loss is by scalp cooling, though most published data on this technique are of poor quality. Fortunately, the condition is usually reversible, and appropriate hair and scalp care along with temporarily wearing a wig may represent the most effective coping strategy. However, some patients may show changes in color and/or texture of regrown hair, and in limited cases the reduction in density may persist.

  7. [Autoimmune hepatitis induced by isotretionine].

    PubMed

    Guzman Rojas, Patricia; Gallegos Lopez, Roxana; Ciliotta Chehade, Alessandra; Scavino, Yolanda; Morales, Alejandro; Tagle, Martín

    2016-01-01

    We describe a case of a teenage patient with the diagnosis of drug induced autoimmune hepatitis. The patient is a 16 years old female, with the past medical history of Hashimoto’s hypothyroidism controlled with levothyroxine, who started treatment with Isotretionin (®Accutane) 20 mg q/12 hours for a total of 3 months for the treatment of severe acne. The physical examination was within normal limits and the results of the laboratory exams are: Baseline values of ALT 28 U/L, AST 28 U/L. Three months later: AST 756 U/L, ALT 1199U/L, alkaline phosphatase 114 U/L, with normal bilirrubin levels throughout the process. The serology studies were negative for all viral hepatitis; ANA titers were positive (1/160) and igG levels were also elevated. A liver biopsy was performed, and was compatible with the diagnosis of autoimmune hepatitis. Corticosteroid therapy was started with Prednisone 40 mg per day one week after stopping the treatment with isotretionin, observing an improvement in the laboratory values. We describe this case and review the world literature since there are no reported cases of Isotretinoin-induced autoimmune hepatitis.

  8. Preference pulses induced by reinforcement.

    PubMed

    Hachiga, Yosuke; Sakagami, Takayuki; Silberberg, Alan

    2014-11-01

    Eight rats responded on concurrent Variable-Ratio 20 Extinction schedules for food reinforcement. The assignment of variable-ratio reinforcement to a left or right lever varied randomly following each reinforcer, and was cued by illumination of a stimulus light above that lever. Postreinforcement preference levels decreased substantially and reliably over time when the lever that just delivered reinforcement was now in extinction; however, if that lever was once again associated with variable ratio, this decrease in same-lever preference tended to be small, and for some subjects, not in evidence. The changes in preference level to the extinction lever were well described by a modified version of Killeen, Hanson, and Osborne's (1978) induction model. Consistent with this model's attribution of preference change to induction, we attribute preference change in this report to a brief period of reinforcer-induced arousal that energizes responding to the lever that delivered the last reinforcer. After a few seconds, this induced responding diminishes, and the operant responding that remains comes under the control of the stimulus light cuing the lever providing variable-ratio reinforcement.

  9. Radiation-induced cardiovascular effects

    NASA Astrophysics Data System (ADS)

    Tapio, Soile

    Recent epidemiological studies indicate that exposure to ionising radiation enhances the risk of cardiovascular mortality and morbidity in a moderate but significant manner. Our goal is to identify molecular mechanisms involved in the pathogenesis of radiation-induced cardiovascular disease using cellular and mouse models. Two radiation targets are studied in detail: the vascular endothelium that plays a pivotal role in the regulation of cardiac function, and the myocardium, in particular damage to the cardiac mitochondria. Ionising radiation causes immediate and persistent alterations in several biological pathways in the endothelium in a dose- and dose-rate dependent manner. High acute and cumulative doses result in rapid, non-transient remodelling of the endothelial cytoskeleton, as well as increased lipid peroxidation and protein oxidation of the heart tissue, independent of whether exposure is local or total body. Proteomic and functional changes are observed in lipid metabolism, glycolysis, mitochondrial function (respiration, ROS production etc.), oxidative stress, cellular adhesion, and cellular structure. The transcriptional regulators Akt and PPAR alpha seem to play a central role in the radiation-response of the endothelium and myocardium, respectively. We have recently started co-operation with GSI in Darmstadt to study the effect of heavy ions on the endothelium. Our research will facilitate the identification of biomarkers associated with adverse cardiac effects of ionising radiation and may lead to the development of countermeasures against radiation-induced cardiac damage.

  10. Inducer Hydrodynamic Load Measurement Devices

    NASA Technical Reports Server (NTRS)

    Skelley, Stephen E.; Zoladz, Thomas F.

    2002-01-01

    Marshall Space Flight Center (MSFC) has demonstrated two measurement devices for sensing and resolving the hydrodynamic loads on fluid machinery. The first - a derivative of the six component wind tunnel balance - senses the forces and moments on the rotating device through a weakened shaft section instrumented with a series of strain gauges. This "rotating balance" was designed to directly measure the steady and unsteady hydrodynamic loads on an inducer, thereby defining both the amplitude and frequency content associated with operating in various cavitation modes. The second device - a high frequency response pressure transducer surface mounted on a rotating component - was merely an extension of existing technology for application in water. MSFC has recently completed experimental evaluations of both the rotating balance and surface-mount transducers in a water test loop. The measurement bandwidth of the rotating balance was severely limited by the relative flexibility of the device itself, resulting in an unexpectedly low structural bending mode and invalidating the higher frequency response data. Despite these limitations, measurements confirmed that the integrated loads on the four-bladed inducer respond to both cavitation intensity and cavitation phenomena. Likewise, the surface-mount pressure transducers were subjected to a range of temperatures and flow conditions in a non-rotating environment to record bias shifts and transfer functions between the transducers and a reference device. The pressure transducer static performance was within manufacturer's specifications and dynamic response accurately followed that of the reference.

  11. Neutrino-Induced Meson Productions

    NASA Astrophysics Data System (ADS)

    Nakamura, Satoshi X.

    We develop a dynamical coupled-channels (DCC) model for neutrino-nucleon reactions in the resonance region, by extending the DCC model that we have previously developed through an analysis of π N,γ N to π N,η N,KΛ ,KΣ reaction data for W ≤ 2.1 GeV. We analyze electron-induced reaction data for both proton and neutron targets to determine the vector current form factors up to Q2 ≤ 3.0 (GeV/c)2. Axial-current matrix elements are derived in accordance with the Partially Conserved Axial Current (PCAC) relation to the πN interactions of the DCC model. As a result, we can uniquely determine the interference pattern between resonant and non-resonant amplitudes. Our calculated cross sections for neutrino-induced single-pion productions are compared with available data, and are found to be in reasonable agreement with the data. We also calculate the double-pion production cross sections in the resonance region, for the first time, with relevant resonance contributions and channel couplings. The result is compared with the double-pion production data. For a future development of a neutrino-nucleus reaction model and/or a neutrino event generator for analyses of neutrino experiments, the DCC model presented here can give a useful input.

  12. Stress proteins induced by arsenic.

    PubMed

    Del Razo, L M; Quintanilla-Vega, B; Brambila-Colombres, E; Calderón-Aranda, E S; Manno, M; Albores, A

    2001-12-01

    The elevated expression of stress proteins is considered to be a universal response to adverse conditions, representing a potential mechanism of cellular defense against disease and a potential target for novel therapeutics. Exposure to arsenicals either in vitro or in vivo in a variety of model systems has been shown to cause the induction of a number of the major stress protein families such as heat shock proteins (Hsp). Among them are members with low molecular weight, such as metallotionein and ubiquitin, as well as ones with masses of 27, 32, 60, 70, 90, and 110 kDa. In most of the cases, the induction of stress proteins depends on the capacity of the arsenical to reach the target, its valence, and the type of exposure, arsenite being the biggest inducer of most Hsp in several organs and systems. Hsp induction is a rapid dose-dependent response (1-8 h) to the acute exposure to arsenite. Thus, the stress response appears to be useful to monitor the sublethal toxicity resulting from a single exposure to arsenite. The present paper offers a critical review of the capacity of arsenicals to modulate the expression and/or accumulation of stress proteins. The physiological consequences of the arsenic-induced stress and its usefulness in monitoring effects resulting from arsenic exposure in humans and other organisms are discussed.

  13. Ion-induced nuclear radiotherapy

    DOEpatents

    Horn, K.M.; Doyle, B.L.

    1996-08-20

    Ion-induced Nuclear Radiotherapy (INRT) is a technique for conducting radiosurgery and radiotherapy with a very high degree of control over the spatial extent of the irradiated volume and the delivered dose. Based upon the concept that low energy, ion induced atomic and nuclear reactions can be used to produce highly energetic reaction products at the site of a tumor, the INRT technique is implemented through the use of a conduit-needle or tube which conducts a low energy ion beam to a position above or within the intended treatment area. At the end of the conduit-needle or tube is a specially fabricated target which, only when struck by the ion beam, acts as a source of energetic radiation products. The inherent limitations in the energy, and therefore range, of the resulting reaction products limits the spatial extent of irradiation to a pre-defined volume about the point of reaction. Furthermore, since no damage is done to tissue outside this irradiated volume, the delivered dose may be made arbitrarily large. INRT may be used both as a point-source of radiation at the site of a small tumor, or as a topical bath of radiation to broad areas of diseased tissue. 25 figs.

  14. Simulations of Cavitating Cryogenic Inducers

    NASA Technical Reports Server (NTRS)

    Dorney, Dan (Technical Monitor); Hosangadi, Ashvin; Ahuja, Vineet; Ungewitter, Ronald J.

    2004-01-01

    Simulations of cavitating turbopump inducers at their design flow rate are presented. Results over a broad range of Nss, numbers extending from single-phase flow conditions through the critical head break down point are discussed. The flow characteristics and performance of a subscale geometry designed for water testing are compared with the fullscale configuration that employs LOX. In particular, thermal depression effects arising from cavitation in cryogenic fluids are identified and their impact on the suction performance of the inducer quantified. The simulations have been performed using the CRUNCH CFD[R] code that has a generalized multi-element unstructured framework suitable for turbomachinery applications. An advanced multi-phase formulation for cryogenic fluids that models temperature depression and real fluid property variations is employed. The formulation has been extensively validated for both liquid nitrogen and liquid hydrogen by simulating the experiments of Hord on hydrofoils; excellent estimates of the leading edge temperature and pressure depression were obtained while the comparisons in the cavity closure region were reasonable.

  15. Hydroxycut-induced Liver Toxicity

    PubMed Central

    Kaswala, DH; Shah, S; Patel, N; Raisoni, S; Swaminathan, S

    2014-01-01

    In the recent era, use of various nutritional supplements is highly encouraged amongst the people of United States. Weight loss supplements are major part of the nutritional supplements and their usage is unregulated in the US. Obesity is a major health concern in the US and Americans spend around $30 billion a year for weight loss supplements. At times, these supplements can be responsible for documented or undocumented adverse drug effects. The health consequences related to these supplements are often overlooked by the general public, even though FDA issues advisories regarding them. One common supplement used for weight loss was Hydroxycut (Iovate Health Sciences Research, Oakville, Ontario, Canada). Hydroxycut was recalled from the market after a FDA warning in May 2009 because of 23 reports of serious health problems ranging from jaundice and elevated liver enzymes to liver damage. 1 This case report adds evidence for Hydroxycut - induced hepatotoxicity. A 27 year old man with right upper quadrant pain and jaundice was found to have elevated liver enzymes and was taking Hydroxycut along with other supplements. Liver biopsy showed drug induced hepatotoxicity. Discontinuation of Hydroxycut dramatically improved liver functions and related symptoms. PMID:24669349

  16. Inducer Hydrodynamic Load Measurement Devices

    NASA Technical Reports Server (NTRS)

    Skelley, Stephen E.; Zoladz, Thomas F.; Turner, Jim (Technical Monitor)

    2002-01-01

    Marshall Space Flight Center (MSFC) has demonstrated two measurement devices for sensing and resolving the hydrodynamic loads on fluid machinery. The first - a derivative of the six-component wind tunnel balance - senses the forces and moments on the rotating device through a weakened shaft section instrumented with a series of strain gauges. This rotating balance was designed to directly measure the steady and unsteady hydrodynamic loads on an inducer, thereby defining both the amplitude and frequency content associated with operating in various cavitation modes. The second device - a high frequency response pressure transducer surface mounted on a rotating component - was merely an extension of existing technology for application in water. MSFC has recently completed experimental evaluations of both the rotating balance and surface-mount transducers in a water test loop. The measurement bandwidth of the rotating balance was severely limited by the relative flexibility of the device itself, resulting in an unexpectedly low structural bending mode and invalidating the higher-frequency response data. Despite these limitations, measurements confirmed that the integrated loads on the four-bladed inducer respond to both cavitation intensity and cavitation phenomena. Likewise, the surface-mount pressure transducers were subjected to a range of temperatures and flow conditions in a non-rotating environment to record bias shifts and transfer functions between the transducers and a reference device. The pressure transducer static performance was within manufacturer's specifications and dynamic response accurately followed that of the reference.

  17. Diet-induced metabolic acidosis.

    PubMed

    Adeva, María M; Souto, Gema

    2011-08-01

    The modern Western-type diet is deficient in fruits and vegetables and contains excessive animal products, generating the accumulation of non-metabolizable anions and a lifespan state of overlooked metabolic acidosis, whose magnitude increases progressively with aging due to the physiological decline in kidney function. In response to this state of diet-derived metabolic acidosis, the kidney implements compensating mechanisms aimed to restore the acid-base balance, such as the removal of the non-metabolizable anions, the conservation of citrate, and the enhancement of kidney ammoniagenesis and urinary excretion of ammonium ions. These adaptive processes lower the urine pH and induce an extensive change in urine composition, including hypocitraturia, hypercalciuria, and nitrogen and phosphate wasting. Low urine pH predisposes to uric acid stone formation. Hypocitraturia and hypercalciuria are risk factors for calcium stone disease. Even a very mild degree of metabolic acidosis induces skeletal muscle resistance to the insulin action and dietary acid load may be an important variable in predicting the metabolic abnormalities and the cardiovascular risk of the general population, the overweight and obese persons, and other patient populations including diabetes and chronic kidney failure. High dietary acid load is more likely to result in diabetes and systemic hypertension and may increase the cardiovascular risk. Results of recent observational studies confirm an association between insulin resistance and metabolic acidosis markers, including low serum bicarbonate, high serum anion gap, hypocitraturia, and low urine pH.

  18. Coalescence-induced nanodroplet jumping

    NASA Astrophysics Data System (ADS)

    Cha, Hyeongyun; Xu, Chenyu; Sotelo, Jesus; Chun, Jae Min; Yokoyama, Yukihiro; Enright, Ryan; Miljkovic, Nenad

    2016-10-01

    Water vapor condensation on superhydrophobic surfaces has received much attention in recent years due to the ability of such surfaces to shed microscale water droplets via coalescence-induced droplet jumping, resulting in heat transfer, anti-icing, and self-cleaning performance enhancement. Here we report the coalescence-induced removal of water nanodroplets (R ≈500 nm ) from superhydrophobic carbon nanotube (CNT) surfaces. The two-droplet coalescence time is measured for varying droplet Ohnesorge numbers, confirming that coalescence prior to jumping is governed by capillary-inertial dynamics. By varying the conformal hydrophobic coating thickness on the CNT surface, the minimum jumping droplet radius is shown to increase with increasing solid fraction and decreasing apparent advancing contact angle, allowing us to explore both hydrodynamic limitations stemming from viscous dissipation and surface adhesion limitations. We find that, even for the smallest nanostructure length scale (≤100 nm) and lowest surface adhesions, nonideal surface interactions and the evolved droplet morphology play defining roles in limiting the minimum size for jumping on real surfaces. The outcomes of this work demonstrate the ability to passively shed nanometric water droplets, which has the potential to further increase the efficiency of systems that can harness jumping droplets for a wide range of energy and water applications.

  19. Amiodarone-induced myxoedema coma

    PubMed Central

    Hassan, Syed; Ayoub, Walaa; Hassan, Mona; Wisgerhof, Max

    2014-01-01

    A 62-year-old man was found to have bradycardia, hypothermia and respiratory failure 3 weeks after initiation of amiodarone therapy for atrial fibrillation. Thyroid-stimulating hormone was found to be 168 μIU/mL (nl. 0.3–5 μIU/mL) and free thyroxine (FT4) was <0.2 ng/dL (nl. 0.8–1.8 ng/dL). He received intravenous fluids, vasopressor therapy and stress dose steroids; he was intubated and admitted to the intensive care unit. He received 500 μg of intravenous levothyroxine in the first 18 h of therapy, and 150 µg intravenous daily thereafter. Haemodynamic improvement, along with complete recovery of mental status, occurred after 48 h. Twelve hours after the initiation of therapy, FT4 was 0.96 ng/dL. The patient was maintained on levothyroxine 175 (g POorally daily. A thyroid ultrasound showed diffuse heterogeneity. The 24 hour excretion of iodine was 3657 (mcg (25–756 ( mcg). The only two cases of amiodarone-induced myxoedema coma in the literature report patient death despite supportive therapy and thyroid hormone replacement. This case represents the most thoroughly investigated case of amiodarone-induced myxoedema coma with a history significant for subclinical thyroid disease. PMID:24729111

  20. Psychosocial aspects of induced abortion.

    PubMed

    Stotland, N L

    1997-09-01

    US anti-abortion groups have used misinformation on the long-term psychological impact of induced abortion to advance their position. This article reviews the available research evidence on the definition, history, cultural context, and emotional and psychiatric sequelae of induced abortion. Notable has been a confusion of normative, transient reactions to unintended pregnancy and abortion (e.g., guilt, depression, anxiety) with serious mental disorders. Studies of the psychiatric aspects of abortion have been limited by methodological problems such as the impossibility of randomly assigning women to study and control groups, resistance to follow-up, and confounding variables. Among the factors that may impact on an unintended pregnancy and the decision to abort are ongoing or past psychiatric illness, poverty, social chaos, youth and immaturity, abandonment issues, ongoing domestic responsibilities, rape and incest, domestic violence, religion, and contraceptive failure. Among the risk factors for postabortion psychosocial difficulties are previous or concurrent psychiatric illness, coercion to abort, genetic or medical indications, lack of social supports, ambivalence, and increasing length of gestation. Overall, the literature indicates that serious psychiatric illness is at least 8 times more common among postpartum than among postabortion women. Abortion center staff should acknowledge that the termination of a pregnancy may be experienced as a loss even when it is a voluntary choice. Referrals should be offered to women who show great emotional distress, have had several previous abortions, or request psychiatric consultation.

  1. Plasmon-induced artificial photosynthesis

    PubMed Central

    Ueno, Kosei; Oshikiri, Tomoya; Shi, Xu; Zhong, Yuqing; Misawa, Hiroaki

    2015-01-01

    We have successfully developed a plasmon-induced artificial photosynthesis system that uses a gold nanoparticle-loaded oxide semiconductor electrode to produce useful chemical energy as hydrogen and ammonia. The most important feature of this system is that both sides of a strontium titanate single-crystal substrate are used without an electrochemical apparatus. Plasmon-induced water splitting occurred even with a minimum chemical bias of 0.23 V owing to the plasmonic effects based on the efficient oxidation of water and the use of platinum as a co-catalyst for reduction. Photocurrent measurements were performed to determine the electron transfer between the gold nanoparticles and the oxide semiconductor. The efficiency of water oxidation was determined through spectroelectrochemical experiments aimed at elucidating the electron density in the gold nanoparticles. A set-up similar to the water-splitting system was used to synthesize ammonia via nitrogen fixation using ruthenium instead of platinum as a co-catalyst. PMID:26052419

  2. Induced gravity II: grand unification

    NASA Astrophysics Data System (ADS)

    Einhorn, Martin B.; Jones, D. R. Timothy

    2016-05-01

    As an illustration of a renormalizable, asymptotically-free model of induced gravity, we consider an SO(10) gauge theory interacting with a real scalar multiplet in the adjoint representation. We show that dimensional transmutation can occur, spontaneously breaking SO(10) to SU(5)⊗U(1), while inducing the Planck mass and a positive cosmological constant, all proportional to the same scale v. All mass ratios are functions of the values of coupling constants at that scale. Below this scale (at which the Big Bang may occur), the model takes the usual form of Einstein-Hilbert gravity in de Sitter space plus calculable corrections. We show that there exist regions of parameter space in which the breaking results in a local minimum of the effective action giving a positive dilaton (mass)2 from two-loop corrections associated with the conformal anomaly. Furthermore, unlike the singlet case we considered previously, some minima lie within the basin of attraction of the ultraviolet fixed point. Moreover, the asymptotic behavior of the coupling constants also lie within the range of convergence of the Euclidean path integral, so there is hope that there will be candidates for sensible vacua. Although open questions remain concerning unitarity of all such renormalizable models of gravity, it is not obvious that, in curved backgrounds such as those considered here, unitarity is violated. In any case, any violation that may remain will be suppressed by inverse powers of the reduced Planck mass.

  3. Shear-Induced Reactive Gelation.

    PubMed

    Brand, Bastian; Morbidelli, Massimo; Soos, Miroslav

    2015-11-24

    In this work, we describe a method for the production of porous polymer materials in the form of particles characterized by narrow pore size distribution using the principle of shear-induced reactive gelation. Poly(styrene-co-divinylbenzene) primary particles with diameter ranging from 80 to 200 nm are used as building blocks, which are assembled into fractal-like clusters when exposed to high shear rates generated in a microchannel. It was found that independent of the primary particle size, it is possible to modulate the internal structure of formed fractal-like aggregates having fractal dimension ranging from 2.4 to 2.7 by varying the residence time in the microchannel. Thermally induced postpolymerization was used to increase the mechanical resilience of such formed clusters. Primary particle interpenetration was observed by SEM and confirmed by light scattering resulting in an increase of fractal dimension. Nitrogen sorption measurements and mercury porosimetry confirmed formation of a porous material with surface area ranging from 20 to 40 m(2)/g characterized by porosity of 70% and narrow pore size distribution with an average diameter around 700 nm without the presence of any micropores. The strong perfusive character of the synthesized material was confirmed by the existence of a plateau of the height equivalent to a theoretical plate measured at high reduced velocities using a chromatographic column packed with the synthesized microclusters.

  4. Shear induced phase transitions induced in edible fats

    NASA Astrophysics Data System (ADS)

    Mazzanti, Gianfranco; Welch, Sarah E.; Marangoni, Alejandro G.; Sirota, Eric B.; Idziak, Stefan H. J.

    2003-03-01

    The food industry crystallizes fats under different conditions of temperature and shear to obtain products with desired crystalline phases. Milk fat, palm oil, cocoa butter and chocolate were crystallized from the melt in a temperature controlled Couette cell. Synchrotron x-ray diffraction studies were conducted to examine the role of shear on the phase transitions seen in edible fats. The shear forces on the crystals induced acceleration of the alpha to beta-prime phase transition with increasing shear rate in milk fat and palm oil. The increase was slow at low shear rates and became very strong above 360 s-1. In cocoa butter the acceleration between beta-prime-III and beta-V phase transition increased until a maximum of at 360 s-1, and then decreased, showing competition between enhanced heat transfer and viscous heat generation.

  5. Anion adsorption induced surface reconstructions

    NASA Astrophysics Data System (ADS)

    Tang, Lei

    2005-11-01

    Surface stress plays an important role in the behavior of solid surfaces. Potential-controlled anion adsorption in electrolytes alters the surface stress of the electrode and results in morphology changes to the surfaces. With a combination of potential-induced surface stress measurement and in situ electrochemical scanning tunneling microscopy (STM), it is demonstrated that anion adsorption induces changes in structure of thin films and modifies the growth morphology and stress evolution in epitaxially grown films. Surface structural transitions in the heteroepitaxial system consisting of one to two gold monolayers on platinum substrates were observed. By increasing the potential, structural transitions, from (1 x 1), to a striped phase, to a hexagonal structure, occurred in the gold bilayer. This hexagonal structure was related to the formation of an ordered sulfate adlayer with a ( 3x7 ) structure. Such transitions were repeatable by cycling the potential. Furthermore, the transitions between various dislocation structures were affected by anion adsorption. The surface composition of the gold bilayer on Pt was measured by underpotential deposition of copper. By subtracting the contribution of a pure Pt surface from the gold bi-layer on Pt, a stress change of -2.4 N/m was observed, which agrees with the stress change of -2.46 N/m predicted to accompany formation of 1.5 MLs of coherent Au on Pt(111) from epitaxy theory. The Cu monolayer deposited on Au(111) from an acid sulfate electrolyte was found to be pseudomorphic while the Cu monolayer formed on Au(111) in vacuum was incoherent. The stress-thickness change associated with the coherent monolayer of copper on Au(111) in electrolyte was -0.6 N/m, while conventional epitaxy theories predict a value of +7.76 N/m. STM results elucidated the sulfate adsorption on the copper monolayer caused an expansion of the layer as evidenced by a Moire Structure. For the Cu monolayer on Au(111), the sulfate-induced expansion

  6. Numerical calculation for cavitation flow of inducer

    NASA Astrophysics Data System (ADS)

    Ning, C.; Wang, Y.; Zhu, Z. T.; Xie, S. F.; Zhao, L. F.; Liu, Z. C.

    2015-01-01

    Inducer has significant effect on improving the cavitation characteristic of centrifugal pump. Several inducers were designed and modeled by Pro/E software. The mesh of flow field was done by ICEM and then was imported to ANSYS CFX to analyze the inducer's cavitation characteristic. Effects of the blade number on the performance of an inducer are investigated in the present paper. The inducers were designed on the basis of identical design flow rate and identical pressure elevation at nominal flow rate. The study focuses on the steady behavior of the inducers in cavitating conditions. Evolutions of performance, torque, mass flow rate, and amplitude of radial forces on the shaft according to the inlet pressure are considered. Furthermore, cavitation instabilities are analyzed in the study. The purpose of the present study is to investigate the pressure distribution and vapour volume fraction distribution through numerical simulations using the Navier-stokes solver with computational fluid dynamics (CFD) code.

  7. The mechanism of PDT-induced apoptosis

    NASA Astrophysics Data System (ADS)

    Cai, Xiongwei; Liu, Timon C.; Ding, Xin-Min; Gu, Ying; Liu, Fan-Guang; Liu, Song-Hao

    2003-12-01

    Photodynamic therapy (PDT) can induce apoptosis in many cancer cells in vitro and in tumors in vivo. Cells become more oxidation with PDT, and maintain differentiation and proliferation, go apoptosis and necrosis with the increase of reactive oxygen species (ROS) concentration. ROS can induce apoptosis through mitochondria by inhibiting respiration chain or oxidative phosphorylation or damaging mitochondrial membrane. ROS can initiate apoptosis through endoplamic reticulum(ER) by opening Ca2+ channel or starting unfold protein response (UPR). ROS can also induce apoptosis through Golgi by producing ganglioside GD3 by use of ceramide, which induces apoptosis by activating caspase-3, JNK and p38 MAPK. It can also induce apoptosis by activating Bip (mitochondria-dependant) or preocaspase-12 (mitochondria- independent) or inhibiting protein synthesizing. There are so complicated cross-talking among different signal pathways or organnells that we think PDT-induced apoptosis is mediated by multiplex pathways and excessive levels in a refined network.

  8. Tenofovir induced lichenoid drug eruption.

    PubMed

    Gupta, Mrinal; Gupta, Heena; Gupta, Anish

    2015-01-01

    Cutaneous adverse reactions are a common complication of anti-retroviral therapy. Tenofovir is a newer anti-retroviral drug belonging to the nucleotide reverse transcriptase inhibitor group. Systemic adverse effects like nausea, vomiting, diarrhea, hepatotoxicity and renal toxicity are common with tenofovir but cutaneous adverse effects are rare. Lichenoid drug eruptions are a common adverse effect seen with a large variety of drugs including antimalarials, antihypertensives, nonsteroidal anti-inflammatory drugs and diuretics. Lichenoid drug eruption is a rare cutaneous adverse effect of tenofovir with only a single case reported till date. Here, we report a case of tenofovir induced lichenoid drug eruption in a 54-year-old human immunodeficiency virus affected male who presented with generalized lichenoid eruption after 6 weeks of initiation of tenofovir and complete clearance on cessation of the drug.

  9. Pressure induced polymerization of Formates

    NASA Astrophysics Data System (ADS)

    Tschauner, Oliver

    2004-03-01

    The discovery of pressure induced polymerization of CO2 inspired us to search for C-O based chain structures forming at high pressure. We used salts of carboxylic acids as starting materials and exposed them to pressures between 10 and 30 GPa. Upon heating to temperatures above 1800 K we observed deprotonation and significant changes in the Raman shifts of C-O streching modes. Structure analysis based on powder diffraction patterns collected at sector 16 of the APS showed formation of extended C-O chain structures with the cations of the salts residing in the interchain spaces. These new high pressure polymers are interesting by their mechanical strength and provide basic molecular patterns of organic metallic conductors.

  10. Front interaction induces excitable behavior

    NASA Astrophysics Data System (ADS)

    Parra-Rivas, P.; Matías, M. A.; Colet, P.; Gelens, L.; Walgraef, D.; Gomila, D.

    2017-02-01

    Spatially extended systems can support local transient excitations in which just a part of the system is excited. The mechanisms reported so far are local excitability and excitation of a localized structure. Here we introduce an alternative mechanism based on the coexistence of two homogeneous stable states and spatial coupling. We show the existence of a threshold for perturbations of the homogeneous state. Subthreshold perturbations decay exponentially. Superthreshold perturbations induce the emergence of a long-lived structure formed by two back to back fronts that join the two homogeneous states. While in typical excitability the trajectory follows the remnants of a limit cycle, here reinjection is provided by front interaction, such that fronts slowly approach each other until eventually annihilating. This front-mediated mechanism shows that extended systems with no oscillatory regimes can display excitability.

  11. Human-induced Arctic moistening.

    PubMed

    Min, Seung-Ki; Zhang, Xuebin; Zwiers, Francis

    2008-04-25

    The Arctic and northern subpolar regions are critical for climate change. Ice-albedo feedback amplifies warming in the Arctic, and fluctuations of regional fresh water inflow to the Arctic Ocean modulate the deep ocean circulation and thus exert a strong global influence. By comparing observations to simulations from 22 coupled climate models, we find influence from anthropogenic greenhouse gases and sulfate aerosols in the space-time pattern of precipitation change over high-latitude land areas north of 55 degrees N during the second half of the 20th century. The human-induced Arctic moistening is consistent with observed increases in Arctic river discharge and freshening of Arctic water masses. This result provides new evidence that human activity has contributed to Arctic hydrological change.

  12. Broadband cavity electromagnetically induced transparency

    SciTech Connect

    Wei Xiaogang; Wang Yanhua; Zhang Jiepeng; Zhu Yifu

    2011-10-15

    Cavity electromagnetically induced transparency (EIT) is created in a three-level atomic system confined in a cavity and coupled to a free-space control laser and is manifested as a narrow transmission peak of a probe laser coupled into the cavity mode and tuned to the two-photon Raman resonance with the control laser. Cavity EIT can be observed with a control laser detuned from the atomic transition frequency in a range limited by the vacuum Rabi splitting of two cavity-atom normal modes. This leads to the broadband cavity EIT obtained in the coupled-cavity-atom system with a free-space, broadband control laser. We report an experimental observation of broadband cavity EIT in cold Rb atoms with a frequency-modulated control laser and discuss its application in multichannel and multifrequency light memory.

  13. Texture induced microwave background anisotropies

    SciTech Connect

    Borrill, Julian; Copeland, Edmund J.; Liddle, Andrew R.; Stebbins, Albert; Veeraraghavan, Shoba

    1994-03-01

    We use numerical simulations to calculate the cosmic microwave background anisotropy induced by the evolution of a global texture field, with special emphasis on individual textures. Both spherically symmetric and general configurations are analyzed, and in the latter case we consider field configurations which exhibit unwinding events and also ones which do not. We compare the results given by evolving the field numerically under both the expanded core (XCORE) and non-linear sigma model (NLSM) approximations with the analytic predictions of the NLSM exact solution for a spherically symmetric self-similar (SSSS) unwinding. We find that the random unwinding configuration spots' typical peak height is 60-75\\% and angular size typically only 10% of those of the SSSS unwinding, and that random configurations without an unwinding event nonetheless may generate indistinguishable hot and cold spots. A brief comparison is made with other work.

  14. Drug-Induced Liver Injury.

    PubMed

    Hamilton, Leslie A; Collins-Yoder, Angela; Collins, Rachel E

    2016-10-01

    Drug-induced liver injury (DILI) can result from both idiosyncratic and intrinsic mechanisms. This article discusses the clinical impact of DILI from a broad range of medications as well as herbal and dietary supplements. Risk factors for idiosyncratic DILI (IDILI) are the result of multiple host, environmental, and compound factors. Some triggers of IDILI often seen in critical care include antibiotics, antiepileptic medications, statins, novel anticoagulants, proton pump inhibitors, inhaled anesthetics, nonsteroidal anti-inflammatory agents, methotrexate, sulfasalazine, and azathioprine. The mechanism of IDILI due to these medications varies, and the resulting damage can be cholestatic, hepatocellular, or mixed. The primary treatment of IDILI is to discontinue the causative agent. DILI due to acetaminophen is intrinsic because the liver damage is predictably aligned with the dose ingested. Acute acetaminophen ingestion can be treated with activated charcoal or N-acetylcysteine. Future areas of research include identification of mitochondrial stress biomarkers and of the patients at highest risk for DILI.

  15. Phenytoin-induced Lyell's syndrome

    PubMed Central

    Lobão, Bárbara; Martins, Claúdio; Sousa, Manuel; Marques, Susana; Pedroso, Ermelinda

    2012-01-01

    Lyell's syndrome or toxic epidermal necrolysis (TEN) is a rare dermatological disease that causes serious morbidity and mortality. It is most commonly drug induced. The authors report the case of a 57-year-old woman who was admitted to our hospital with severe rash all over the body. She had been previously submitted to brain surgery for total resection of a large meningioma and medicated with phenytoin for seizures prophylaxis. During this treatment, erythematous lesions and blisters were observed first on her face and trunk and then spreading to the entire body. Detachment of the skin, as well as mucous involvement especially of mouth and conjunctiva, was also observed. TEN was diagnosed, and phenytoin was discontinued. Intravenous fluids, systemic steroids and tightened infection control measures were implemented. After 10 days, skin recovery and re-epithelialisation were established, temperature decreased and mucosal complications stabilised. The patient was discharged after 1 month of hospitalisation. PMID:23230258

  16. Radiocontrast-Induced Renal Failure

    PubMed Central

    Misson, Robert T.; Cutler, Ralph E.

    1985-01-01

    Review of the literature concerning contrast-induced renal dysfunction shows that the currently used agents are remarkably safe with careful patient selection. Clinically apparent kidney failure after their use is essentially nonexistent in those without preexistent renal insufficiency. The incidence rises rapidly in those with azotemia from any cause, however, and diabetic persons with nephropathy are perhaps at special risk. Vigorous volume expansion is possibly effective as a preventive measure and may attenuate adverse effects in those in whom postcontrast dysfunction occurs. New agents are becoming available. It is not yet known if these will prove safer or cost-effective. They have some experimentally demonstrated and theoretic advantages over the presently used agents. PMID:4013281

  17. Hemolysis induced by PMIVSD occluder.

    PubMed

    Rao, D Sheshagiri; Barik, Ramachandra; Siva Prasad, Akula

    2016-09-01

    Hemolysis related to occluder, prosthetic valve, and prosthetic ring used for mitral valve annuloplasty are not very unusual. However, hemolysis related to transcathetor closure of post-myocardial infarction ventricular septal defect (PMIVSD) is infrequent. A close follow-up for spontaneous resolution with or without blood transfusion has been reported in a few cases. Occasionally, surgical retrieval is unavoidable or lifelong blood transfusion is required if surgery cannot be done because of higher risk. In this illustration, we have showed a close follow-up of a case of hemolysis induced by atrial septal occluder used for VSD closure after myocardial infarction. Despite successful device closure of PMIVSD which is difficult, a close watch is needed for complications like residual leak, device embolization, and hemolysis.

  18. Statin induced necrotizing autoimmune myopathy.

    PubMed

    Babu, Suma; Li, Yuebing

    2015-04-15

    Statin induced necrotizing autoimmune myopathy (SINAM) is a recently characterized entity belonging to the spectrum of statin myotoxicity. It is a more severe form, and is usually associated with significant proximal muscle weakness, strikingly elevated creatine kinase levels and persistent symptoms despite statin discontinuation. The characteristic pathological finding is a marked muscle fiber necrosis with minimal or no inflammation on muscle biopsy. SINAM is an autoimmune disorder associated with an antibody against 3-hydroxy-3-methyglutaryl-coenzyme A reductase (HMGCR), and the antibody titer is a useful marker for assessing treatment response. However, anti-HMGCR positive myopathies are also caused by unknown etiologies other than statin exposure, especially in the younger population. SINAM should be promptly recognized as immunosuppressive therapy can improve its clinical outcome significantly. Further research is needed to elucidate its pathogenesis and provide evidence based guidelines for management.

  19. Pressure induced metallization of Germane

    NASA Astrophysics Data System (ADS)

    Martinez-Canales, M.; Bergara, A.; Feng, J.; Grochala, W.

    2006-09-01

    Recently reported superconductivity in lithium under pressure has renewed the interest on hydrogen and hydrogen-rich systems in the long standing quest for room temperature superconductivity. Although the required metallization of pure hydrogen cannot be achieved within correct experimental capabilities, chemical precompression exerted by heavier atoms in compounds with a large hydrogen content is expected to imply that lower pressures might be required to attain the metallic transition in these alloys. In this article, we present an ab initio analysis of pressure induced metallization of germane, as a particular case between group IVa hydrides. According to our calculations, metallization of germane is predicted to occur at an experimentally accessible pressure of around 70 GPa, which corresponds to a compression factor of 3.4.

  20. Exercise-induced cardiac remodeling.

    PubMed

    Weiner, Rory B; Baggish, Aaron L

    2012-01-01

    Early investigations in the late 1890s and early 1900s documented cardiac enlargement in athletes with above-normal exercise capacity and no evidence of cardiovascular disease. Such findings have been reported for more than a century and continue to intrigue scientists and clinicians. It is well recognized that repetitive participation in vigorous physical exercise results in significant changes in myocardial structure and function. This process, termed exercise-induced cardiac remodeling (EICR), is characterized by structural cardiac changes including left ventricular hypertrophy with sport-specific geometry (eccentric vs concentric). Associated alterations in both systolic and diastolic functions are emerging as recognized components of EICR. The increasing popularity of recreational exercise and competitive athletics has led to a growing number of individuals exhibiting these findings in routine clinical practice. This review will provide an overview of EICR in athletes.

  1. Ciprofloxacin-induced erythema multiforme.

    PubMed

    Shilpashree, H S; Sarapur, Shriprasad

    2012-10-01

    Ciprofloxacin is one of the most commonly used antibacterial agents with relatively few side effects. Serious adverse reactions reported with ciprofloxacin are rare with an incidence of 0.6%. One of the side effects of ciprofloxacin is erythema multiforme (EM). EM is an acute, self -limiting mucocutaneous hypersensitivity syndrome. It exhibits a diverse etiology, often recurs, has unusual clinical features and is of uncertain etiopathogenesis. It usually exhibits a distinctive skin or mucosal lesions that are characterized by combination of bullae, papules, macules or ulcers. It is most probably an immunologically mediated process. With the use of ciprofloxacin becoming more and more widespread, fatal complications of ciprofloxacin should be borne in mind. In this article we present a case of ciprofloxacin induced erythema multiforme in 40 year old woman.

  2. Canagliflozin-Induced Diabetic Ketoacidosis

    PubMed Central

    Turner, Jessica; Begum, Tahmina; Smalligan, Roger D.

    2016-01-01

    Introduction: Sodium-glucose co-transporter 2 (SGLT-2) inhibitors are relatively new antihyperglycemic agents that lower renal glucose reabsorption. They are used as adjunctive therapy to standard diabetes treatment. Case Report: We present the case of a 62-year-old woman with a past medical history of type 2 diabetes mellitus and sudden-onset diabetic ketoacidosis (DKA). Use of canagliflozin, a SGLT-2 inhibitor, was determined to be the cause of the DKA. The patient ultimately recovered after 5 days in the intensive care unit. She was changed to long- and short-acting insulins and instructed to avoid canagliflozin. Conclusion: Although SGLT-2 inhibitors are effective at lowering a patient’s hemoglobin A1C, physicians must be aware of the rare but dangerous potential adverse effect of inducing DKA. This article reports an illustrative case and presents a review of the literature. PMID:27635409

  3. Laser-induced magnetization curve

    NASA Astrophysics Data System (ADS)

    Takayoshi, Shintaro; Sato, Masahiro; Oka, Takashi

    2014-12-01

    We propose an all optical ultrafast method to highly magnetize general quantum magnets using a circularly polarized terahertz laser. The key idea is to utilize a circularly polarized laser and its chirping. Through this method, one can obtain magnetization curves of a broad class of quantum magnets as a function of time even without any static magnetic field. We numerically demonstrate the laser-induced magnetization process in realistic quantum spin models and find a condition for the realization. The onset of magnetization can be described by a many-body version of Landau-Zener mechanism. In a particular model, we show that a plateau state with topological properties can be realized dynamically.

  4. Regeneration inducers in limb regeneration.

    PubMed

    Satoh, Akira; Mitogawa, Kazumasa; Makanae, Aki

    2015-08-01

    Limb regeneration ability, which can be observed in amphibians, has been investigated as a representative phenomenon of organ regeneration. Recently, an alternative experimental system called the accessory limb model was developed to investigate early regulation of amphibian limb regeneration. The accessory limb model contributed to identification of limb regeneration inducers in urodele amphibians. Furthermore, the accessory limb model may be applied to other species to explore universality of regeneration mechanisms. This review aims to connect the insights recently gained to emboss universality of regeneration mechanisms among species. The defined molecules (BMP7 (or2) + FGF2 + FGF8) can transform skin wound healing to organ (limb) regeneration responses. The same molecules can initiate regeneration responses in some species.

  5. Nanoparticle-induced pulmonary toxicity.

    PubMed

    Li, Jasmine Jia'en; Muralikrishnan, Sindu; Ng, Cheng-Teng; Yung, Lin-Yue Lanry; Bay, Boon-Huat

    2010-09-01

    In recent decades, advances in nanotechnology engineering have given rise to the rapid development of many novel applications in the biomedical field. However, studies into the health and safety of these nanomaterials are still lacking. The main concerns are the adverse effects to health caused by acute or chronic exposure to nanoparticles (NPs), especially in the workplace environment. The lung is one of the main routes of entry for NPs into the body and, hence, a likely site for accumulation of NPs. Once NPs enter the interstitial air spaces and are quickly taken up by alveolar cells, they are likely to induce toxic effects. In this review, we highlight the different aspects of lung toxicity resulting from NP exposure, such as generation of oxidative stress, DNA damage and inflammation leading to fibrosis and pneumoconiosis, and the underlying mechanisms causing pulmonary toxicity.

  6. Capecitabine-Induced Coronary Vasospasm

    PubMed Central

    Henry, Danish; Rudzik, Francine; Butts, Allison; Mathew, Aju

    2016-01-01

    Capecitabine, an oral prodrug of 5-fluorouracil (5-FU), is approved for early-stage and advanced colorectal cancer and metastatic breast cancer. Cardiotoxicity of 5-FU is well described in the literature. However, cardiac adverse effects of capecitabine are poorly described. We report a case of coronary vasospasm induced by capecitabine. A 41-year-old female with metastatic breast cancer presented with chest pain 3 days after starting capecitabine. The chest pain was relieved by rest and exacerbated by exertion. Her physical examination was unremarkable except for a rapid heart rate of 100 bpm. Electrocardiogram test showed no acute ischemic changes. Troponin tests were negative. CT angiography of the chest was negative for acute pulmonary embolism. An echocardiogram showed a left ventricular ejection fraction of 60% without any wall motion abnormalities. The chest pain resolved with aspirin and analgesic use. She was discharged following an inconclusive cardiac workup. Further use of capecitabine was discontinued. PMID:27920693

  7. Candesartan cilexetil induced pustular psoriasis.

    PubMed

    Kawamura, Ai; Ochiai, Toyoko

    2003-01-01

    Pustular eruptions caused by anti-hypertension drugs are relatively rare. They have been reported with beta-adrenergic blocking agents, calcium channel blocker and angiotensin converting enzyme (ACE) inhibitors. Angiotensin II type 1 (AT 1) receptor antagonists, as a new class of drug for hypertension, has become an established and popular treatment. We describe a patient with generalized pustular psoriasis induced by candesartan cilexetil (AT1 receptor antagonist), who was previously diagnosed as flexural psoriasis. It is known that AT1 receptor antagonists do not increase the bradykinin level, inhibiting the renin-angiotensin system more potently than ACE inhibitor. But our results suggest that AT 1 receptor antagonists could have some ACE inhibitor potency as an up-regulator for bradykinin in our patient, with pustular eruptions developing on the psoriatic background. To the best of our knowledge, there have been no reported cases of pustular psoriasis associated with AT1 receptor antagonists.

  8. Levetiracetam-induced eosinophilic pneumonia.

    PubMed

    Fagan, Aisling; Fuld, Jonathan; Soon, Elaine

    2017-03-08

    Levetiracetam is widely regarded as a benign antiepileptic drug, compared to older antiepileptic medication. We report a case of eosinophilic pneumonia due to levetiracetam use in a non-smoking woman aged 59 years with no previous respiratory history. Our patient presented with exertional breathlessness and marked desaturation on exertion. She displayed 'reverse bat-wing' infiltrates on her chest radiograph and peripheral eosinophilia on a complete blood count. Her symptoms, radiology and peripheral eosinophilia resolved completely with cessation of levetiracetam and a course of prednisolone. This is the first report of isolated eosinophilic pneumonia due to levetiracetam. Other reports of levetiracetam-induced eosinophilia describe drug rash, eosinophilia and systemic symptoms (DRESS syndrome). Detection of pulmonary drug reactions requires a careful drug history and high index of suspicion. Identifying and reporting a causative agent is crucially important, as cessation of the drug is essential for resolution of the syndrome.

  9. Radiation-Induced Vaccination to Breast Cancer

    DTIC Science & Technology

    2015-10-01

    Award Number: W81XWH-11-1-0531 TITLE: Radiation-Induced Vaccination to Breast Cancer PRINCIPAL INVESTIGATOR: William H. McBride CONTRACTING...FORM TO THE ABOVE ADDRESS. 1. REPORT DATE 2. REPORT TYPE Annual 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Radiation-Induced Vaccination to...determine abscopal responses that are hypothesized to be due to RT- induced vaccination . RT was started 10 days after the first and 3rd dose of

  10. Seborrheic dermatitis in neuroleptic-induced parkinsonism.

    PubMed

    Binder, R L; Jonelis, F J

    1983-06-01

    An increased prevalence of seborrheic dermatitis has previously been noted in idiopathic Parkinson's disease and in postencephalitic parkinsonism. Our study of 42 hospitalized patients with drug-induced parkinsonism and 47 hospitalized psychiatric patients without that disorder showed a statistically significant higher prevalence of clinically diagnosed seborrheic dermatitis in the group with drug-induced parkinsonism (59.5% v 15%). To our knowledge, this is the first report of an increased prevalence of seborrheic dermatitis with drug-induced parkinsonism.

  11. Induced activation study of LDEF

    NASA Technical Reports Server (NTRS)

    Harmon, B. A.; Fishman, G. J.; Parnell, T. A.; Laird, C. E.

    1993-01-01

    Analysis of the induced radioactivity of the Long Duration Exposure Facility (LDEF) is continuing with extraction of specific activities for various spacecraft materials. Data and results of activation measurements from eight facilities are being collected for interpretation at Eastern Kentucky University and NASA/Marshall Space Flight Center. The major activation mechanism in LDEF components is the proton flux in the South Atlantic Anomaly (SAA). This flux is highly anisotropic, and could be sampled by taking advantage of the gravity-gradient stabilization of the LDEF. The directionally-dependent activation due to these protons was clearly observed in the data from aluminum experiment tray clamps (reaction product Na-22), steel trunnions (reaction product Mn-54 and others) and is also indicated by the presence of a variety of nuclides in other materials. A secondary production mechanism, thermal neutron capture, was observed in cobalt, indium, and tantalum, which are known to have large capture cross sections. Experiments containing samples of these metals and significant amounts of thermalizing low atomic number (Z) material showed clear evidence of enhanced activation of Co-60, In-114m, and Ta-182. Other mechanisms which activate spacecraft material that are not as easily separable from SAA proton activation, such as galactic proton bombardment and secondary production by fast neutrons, are being investigated by comparison to radiation environmental calculations. Deviations from one-dimensional radiation models indicate that these mechanisms are more important at greater shielding depths. The current status of the induced radioactivity measurements as of mid-year 1992 are reviewed. Specific activities for a number of materials which show SAA effects and thermal neutron capture are presented. The results for consistency by combining data from the participating institutions is also examined.

  12. Nivolumab-induced thyroid dysfunction.

    PubMed

    Tanaka, Ryota; Fujisawa, Yasuhiro; Maruyama, Hiroshi; Nakamura, Yasuhiro; Yoshino, Koji; Ohtsuka, Mikio; Fujimoto, Manabu

    2016-06-01

    Nivolumab (ONO-4538) is an anti-programmed death-1 specific monoclonal antibody, which has become a standard treatment for metastatic malignant melanoma. Nivolumab induces autoimmune adverse events, defined as immune-related adverse events. Herein, we report a case of nivolumab-induced thyroid dysfunction in the clinical setting. Fourteen patients were treated with nivolumab at our institute, of which three developed thyroid dysfunction, an incidence higher than previously reported in the initial clinical trials. Interestingly, one patient achieved complete remission; suggesting that in some patients, the occurrence of immune-related adverse events, including thyroid dysfunction, might reflect the drug's antitumour efficacy. No patient died or discontinued nivolumab treatment owing to thyroid dysfunction. Although thyroid dysfunction first appeared to be asymptomatic, two of the three patients developed symptoms related to hypothyroidism soon after, requiring hormone replacement therapy. Another patient developed hyperthyroidism that was initially asymptomatic; the patient subsequently developed myalgia with fever >39.5°C after two additional courses of nivolumab. Treatment with nivolumab was therefore discontinued, and treatment with prednisolone was initiated. Symptoms resolved within a few days, and thyroid function normalized. Thyroid dysfunction is sometimes difficult to diagnose because its symptoms similar to those of many other diseases. In addition, thyroid-related immune-related adverse events may present with unique symptoms such as myalgia with high fever, abruptly worsening patients' quality of life. Consequently, thyroid dysfunction should be considered as a possible immune-related adverse event. Thus, it is important to test for thyroid dysfunction at baseline and before the administration of each nivolumab dose if possible.

  13. Fisheries-induced disruptive selection.

    PubMed

    Landi, Pietro; Hui, Cang; Dieckmann, Ulf

    2015-01-21

    Commercial harvesting is recognized to induce adaptive responses of life-history traits in fish populations, in particular by shifting the age and size at maturation through directional selection. In addition to such evolution of a target stock, the corresponding fishery itself may adapt, in terms of fishing policy, technological progress, fleet dynamics, and adaptive harvest. The aim of this study is to assess how the interplay between natural and artificial selection, in the simplest setting in which a fishery and a target stock coevolve, can lead to disruptive selection, which in turn may cause trait diversification. To this end, we build an eco-evolutionary model for a size-structured population, in which both the stock׳s maturation schedule and the fishery׳s harvest rate are adaptive, while fishing may be subject to a selective policy based on fish size and/or maturity stage. Using numerical bifurcation analysis, we study how the potential for disruptive selection changes with fishing policy, fishing mortality, harvest specialization, life-history tradeoffs associated with early maturation, and other demographic and environmental parameters. We report the following findings. First, fisheries-induced disruptive selection is readily caused by commonly used fishing policies, and occurs even for policies that are not specific for fish size or maturity, provided that the harvest is sufficiently adaptive and large individuals are targeted intensively. Second, disruptive selection is more likely in stocks in which the selective pressure for early maturation is naturally strong, provided life-history tradeoffs are sufficiently consequential. Third, when a fish stock is overexploited, fisheries targeting only large individuals might slightly increase sustainable yield by causing trait diversification (even though the resultant yield always remains lower than the maximum sustainable yield that could be obtained under low fishing mortality, without causing disruptive

  14. UVRAG Deficiency Exacerbates Doxorubicin-Induced Cardiotoxicity.

    PubMed

    An, Lin; Hu, Xiao-Wen; Zhang, Shasha; Hu, Xiaowen; Song, Zongpei; Naz, Amber; Zi, Zhenguo; Wu, Jian; Li, Can; Zou, Yunzeng; He, Lin; Zhu, Hongxin

    2017-02-22

    Doxorubicin (DOX) is an effective chemotherapeutic drug in the treatment of various types of cancers. However, its clinical application has been largely limited by potential development of cardiotoxicity. Previously we have shown that ultra-violet radiation resistance-associated gene (UVRAG), an autophagy-related protein, is essential for the maintenance of autophagic flux in the heart under physiological conditions. Here, we sought to determine the role of UVRAG-mediated autophagy in DOX-induced cardiotoxicity. Mouse models of acute or chronic DOX-induced cardiotoxicity were established. UVRAG deficiency exacerbated DOX-induced mortality and cardiotoxicity manifested by increased cytoplasmic vacuolization, enhanced collagen accumulation, elevated serum activities of lactate dehydrogenase and myocardial muscle creatine kinase, higher ROS levels, aggravated apoptosis and more depressed cardiac function. Autophagic flux was impaired in DOX-induced cardiotoxicity. UVRAG deficiency aggravated impaired autophagic flux in DOX-induced cardiotoxicity. Intermittent fasting restored autophagy and ameliorated pathological alterations of DOX-induced cardiotoxicity. Collectively, our data suggest that UVRAG deficiency exacerbates DOX-induced cardiotoxicity, at least in part, through aggravation of DOX-induced impaired autophagic flux. Intermittent fasting, which restores blunted autophagic flux and ameliorates pathology in the mouse models of DOX-induced cardiotoxicity, may be used as a potential preventive or therapeutic approach for DOX cardiotoxicity.

  15. UVRAG Deficiency Exacerbates Doxorubicin-Induced Cardiotoxicity

    PubMed Central

    An, Lin; Hu, Xiao-wen; Zhang, Shasha; Hu, Xiaowen; Song, Zongpei; Naz, Amber; Zi, Zhenguo; Wu, Jian; Li, Can; Zou, Yunzeng; He, Lin; Zhu, Hongxin

    2017-01-01

    Doxorubicin (DOX) is an effective chemotherapeutic drug in the treatment of various types of cancers. However, its clinical application has been largely limited by potential development of cardiotoxicity. Previously we have shown that ultra-violet radiation resistance-associated gene (UVRAG), an autophagy-related protein, is essential for the maintenance of autophagic flux in the heart under physiological conditions. Here, we sought to determine the role of UVRAG-mediated autophagy in DOX-induced cardiotoxicity. Mouse models of acute or chronic DOX-induced cardiotoxicity were established. UVRAG deficiency exacerbated DOX-induced mortality and cardiotoxicity manifested by increased cytoplasmic vacuolization, enhanced collagen accumulation, elevated serum activities of lactate dehydrogenase and myocardial muscle creatine kinase, higher ROS levels, aggravated apoptosis and more depressed cardiac function. Autophagic flux was impaired in DOX-induced cardiotoxicity. UVRAG deficiency aggravated impaired autophagic flux in DOX-induced cardiotoxicity. Intermittent fasting restored autophagy and ameliorated pathological alterations of DOX-induced cardiotoxicity. Collectively, our data suggest that UVRAG deficiency exacerbates DOX-induced cardiotoxicity, at least in part, through aggravation of DOX-induced impaired autophagic flux. Intermittent fasting, which restores blunted autophagic flux and ameliorates pathology in the mouse models of DOX-induced cardiotoxicity, may be used as a potential preventive or therapeutic approach for DOX cardiotoxicity. PMID:28225086

  16. Dynamics of cavitating cascades and inducer pumps

    NASA Technical Reports Server (NTRS)

    Brennen, C. E.; Acosta, A. J.

    1981-01-01

    Report chronicles advances in understanding and predicting unsteady dynamic characteristics of cavitating cascades and inducer pumps. It includes bibliography of 19 papers authored between 1972 and 1980.

  17. [Induced abortion in China: problems and interventions].

    PubMed

    Wu, Shang-chun; Qiu, Hong-yan

    2010-10-01

    Pooled literatures showed that the induced abortion in China faces many problems:the number of induced abortion remains large; most cases are young and nulliparity women; the frequency of abortion is high; and the interval between one and another abortion is short. Health promotion strategies should be applied to address these problems. It is important to increase the population's awareness of contraception,especially among nulliparity and migrant populations. Routine and effective contraceptive methods should be recommended and emphasized during induced abortion and delivery to lower the rate of induced abortion.

  18. An evaluation of a hubless inducer and a full flow hydraulic turbine driven inducer boost pump

    NASA Technical Reports Server (NTRS)

    Lindley, B. K.; Martinson, A. R.

    1971-01-01

    The purpose of the study was to compare the performance of several configurations of hubless inducers with a hydrodynamically similar conventional inducer and to demonstrate the performance of a full flow hydraulic turbine driven inducer boost pump using these inducers. A boost pump of this type consists of an inducer connected to a hydraulic turbine with a high speed rotor located in between. All the flow passes through the inducer, rotor, and hydraulic turbine, then into the main pump. The rotor, which is attached to the main pump shaft, provides the input power to drive the hydraulic turbine which, in turn, drives the inducer. The inducer, rotating at a lower speed, develops the necessary head to prevent rotor cavitation. The rotor speed is consistent with present main engine liquid hydrogen pump designs and the overall boost pump head rise is sufficient to provide adequate main pump suction head. This system would have the potential for operating at lower liquid hydrogen tank pressures.

  19. Geldanamycin Prevents Hemorrhage-Induced ATP Loss by Overexpressing Inducible HSP70 and Activating Pyruvate Dehydrogenase

    DTIC Science & Technology

    2006-03-24

    levels were determined using the ATP Bioluminescence Assay Kit HS II (Roche; Mannheim, Germany). Luminescence was measured with a TD-20/20...Geldanamycin prevents hemorrhage-induced ATP loss by overexpressing inducible HSP70 and activating pyruvate dehydrogenase Juliann G. Kiang,1,2,3...Geldanamycin prevents hemorrhage-induced ATP loss by overexpressing inducible HSP70 and activating pyruvate dehy- drogenase. Am J Physiol Gastrointest

  20. Towards inducing superconductivity into graphene

    NASA Astrophysics Data System (ADS)

    Efetov, Dmitri K.

    Graphenes transport properties have been extensively studied in the 10 years since its discovery in 2004, with ground-breaking experimental observations such as Klein tunneling, fractional quantum Hall effect and Hofstadters butterfly. Though, so far, it turned out to be rather poor on complex correlated electronic ground states and phase transitions, despite various theoretical predictions. The purpose of this thesis is to help understanding the underlying theoretical and experimental reasons for the lack of strong electronic interactions in graphene, and, employing graphenes high tunability and versatility, to identify and alter experimental parameters that could help to induce stronger correlations. In particular graphene holds one last, not yet experimentally discovered prediction, namely exhibiting intrinsic superconductivity. With its vanishingly small Fermi surface at the Dirac point, graphene is a semi-metal with very weak electronic interactions. Though, if it is doped into the metallic regime, where the size of the Fermi surface becomes comparable to the size of the Brillouin zone, the density of states becomes sizeable and electronic interactions are predicted to be dramatically enhanced, resulting in competing correlated ground states such as superconductivity, magnetism and charge density wave formation. Following these predictions, this thesis first describes the creation of metallic graphene at high carrier doping via electrostatic doping techniques based on electrolytic gates. Due to graphenes surface only properties, we are able to induce carrier densities above n>1014 cm-2 (epsilonF>1eV) into the chemically inert graphene. While at these record high carrier densities we yet do not observe superconductivity, we do observe fundamentally altered transport properties as compared to semi-metallic graphene. Here, detailed measurements of the low temperature resistivity reveal that the electron-phonon interactions are governed by a reduced, density

  1. Hydralazine-induced cholestatic hepatitis.

    PubMed

    Hassan, Ahad; Hammad, Raza; Cucco, Robert; Niranjan, Selva

    2009-01-01

    Hydralazine has been widely used for treating hypertension, particularly in patients with renal failure. We report a case on a patient in whom we believe the drug was implicated in an otherwise unexplained disturbance of liver function. A 63-year-old African-American female with medical history of hypertension and end-stage renal disease (on hemodialysis) was admitted to the hospital with epigastric pain and jaundice. The symptoms started about 1 week ago. Initial laboratory tests showed abnormal liver enzymes with elevated conjugated bilirubin and alkaline phosphatase suggestive of cholestatic jaundice. Amylase and lipase were normal. Abdominal ultrasound showed normal caliber common bile duct without evidence of obstruction. Abdominal CT scan does not show any evidence of intra- or extrahepatic biliary ductal dilatation, and no mass lesions were seen in the pancreas. Further blood chemistry showed worsening of liver enzymes and increased bilirubin over the next 2-3 days. Magnetic resonance cholangiopancreatography failed to show any evidence of intra- or extrahepatic biliary ductal dilatation. No other laboratory evidence of cholestatic jaundice was found. Before proceeding for invasive diagnostic procedure, that is, endoscopic retrograde cholangiopancreatography, the patient's drug history was reviewed. She was on hydralazine 75 mg 3 times per day, started 5 months ago. At that time, her liver function tests were normal. As we could not find any other cause of cholestatic jaundice, we attributed this as a side effect of hydralazine. A trial was given by stopping the hydralazine. It was seen that there was significant improvement in the liver function enzymes over the next week. Complete clinical and biochemical recovery occurred over the next 4 weeks. Liver injury after long-term therapy with hydralazine and after short-term therapy with hydralazine (2-10 days) has been described. Hydralazine-induced hepatotoxicity may manifest as hypersensitivity-type injury

  2. Psychiatric sequelae of induced abortion.

    PubMed

    Gibbons, M

    1984-03-01

    An attempt is made to identify and document the problems of comparative evaluation of the more recent studies of psychiatric morbidity after abortion and to determine the current consensus so that when the results of the joint RCGP/RCOG study of the sequelae of induced abortion become available they can be viewed in a more informed context. The legalization of abortion has provided more opportunities for studies of subsequent morbidity. New laws have contributed to the changing attitudes of society, and the increasing acceptability of the operation has probably influenced the occurrence of psychiatric sequelae. The complexity of measuring psychiatric sequelae is evident from the many terms used to describe symptomatology and behavioral patterns and from the number of assessment techniques involved. Numerous techniques have been used to quantify psychiatric sequelae. Several authors conclude that few psychiatric problems follow an induced abortion, but many studies were deficient in methodology, material, or length of follow-up. A British study in 1975 reported a favorable outcome for a "representative sample" of 50 National Health Service patients: 68% of these patients had an absence of or only mild feelings of guilt, loss, or self reproach and considered abortion as the best solution to their problem. The 32% who had an adverse outcome reported moderate to severe feelings of guilt, regret, loss, and self reproach, and there was evidence of mental illness. In most of these cases the adverse outcome was related to the patient's environment since the abortion. A follow-up study of 126 women, which compared the overall reaction to therapeutic abortion between women with a history of previous mild psychiatric illness and those without reported that a significantly different emotional reaction could not be demonstrated between the 2 groups. In a survey among women seeking an abortion 271 who were referred for a psychiatric opinion regarding terminations of pregnancy

  3. Organophosphate-induced delayed polyneuropathy.

    PubMed

    Lotti, Marcello; Moretto, Angelo

    2005-01-01

    Organophosphate-induced delayed polyneuropathy (OPIDP) is a rare toxicity resulting from exposure to certain organophosphorus (OP) esters. It is characterised by distal degeneration of some axons of both the peripheral and central nervous systems occurring 1-4 weeks after single or short-term exposures. Cramping muscle pain in the lower limbs, distal numbness and paraesthesiae occur, followed by progressive weakness, depression of deep tendon reflexes in the lower limbs and, in severe cases, in the upper limbs. Signs include high-stepping gait associated with bilateral foot drop and, in severe cases, quadriplegia with foot and wrist drop as well as pyramidal signs. In time, there might be significant recovery of the peripheral nerve function but, depending on the degree of pyramidal involvement, spastic ataxia may be a permanent outcome of severe OPIDP. Human and experimental data indicate that recovery is usually complete in the young. At onset, the electrophysiological changes include reduced amplitude of the compound muscle potential, increased distal latencies and normal or slightly reduced nerve conduction velocities. The progression of the disease, usually over a few days, may lead to non-excitability of the nerve with electromyographical signs of denervation. Nerve biopsies have been performed in a few cases and showed axonal degeneration with secondary demyelination. Neuropathy target esterase (NTE) is thought to be the target of OPIDP initiation. The ratio of inhibitory powers for acetylcholinesterase and NTE represents the crucial guideline for the aetiological attribution of OP-induced peripheral neuropathy. In fact, pre-marketing toxicity testing in animals selects OP insecticides with cholinergic toxicity potential much higher than that to result in OPIDP. Therefore, OPIDP may develop only after very large exposures to insecticides, causing severe cholinergic toxicity. However, this was not the case with certain triaryl phosphates that were not used as

  4. Innovation Inducement Prizes: Connecting Research to Policy

    ERIC Educational Resources Information Center

    Besharov, Douglas J.; Williams, Heidi

    2012-01-01

    Innovation inducement prizes have been used for centuries. In the United States, a recent federal policy change--the America COMPETES Reauthorization Act of 2010--clarified and simplified a path by which all federal agencies can offer innovation inducement prizes, thus intensifying interest in how government agencies can most effectively design…

  5. Noise-Induced Hearing Loss (NIHL).

    ERIC Educational Resources Information Center

    Seidman, Michael D.

    1999-01-01

    This article provides an overview of noise-induced hearing loss (NIHL), the leading cause of occupationally induced hearing loss in industrialized countries. It discusses causes of NIHL and compelling evidence that reactive oxygen metabolites and cochlear hypoprefusion are responsible for the destruction of cochlear hair cells. Prevention is also…

  6. Induced topological pressure for topological dynamical systems

    SciTech Connect

    Xing, Zhitao; Chen, Ercai

    2015-02-15

    In this paper, inspired by the article [J. Jaerisch et al., Stochastics Dyn. 14, 1350016, pp. 1-30 (2014)], we introduce the induced topological pressure for a topological dynamical system. In particular, we prove a variational principle for the induced topological pressure.

  7. Low speed inducers for cryogenic upper stages

    NASA Technical Reports Server (NTRS)

    King, J. A.

    1973-01-01

    Briefing charts are presented, which were used in an oral presentation of the results and recommendations for the design and analysis of low speed hydrogen and oxygen inducers and their drive systems applicable to the space tug. A discussion of the design of the 15K and RL-10 inducers is included.

  8. Mechanisms of chemical-induced porphyrinopathies

    SciTech Connect

    Silbergeld, E.K. Fowler, B.A.

    1987-01-01

    This book contains 45 selections. Some of the titles are: Genetic Regulation of the Heme Pathway; Porphyrins in Urine as an Indication of Exposure to Chlorinated Hydrocarbons; Mechanisms of PCB-induced Porphyria and Yusho Disease; and Lead-Induced Abnormalities of Porphyrin Metabolism: The Relationship with Iron Deficiency.

  9. Radiation-Induced Vaccination to Breast Cancer

    DTIC Science & Technology

    2014-10-01

    Award Number: W81XWH-11-1-0531 TITLE: Radiation-Induced Vaccination to Breast Cancer PRINCIPAL INVESTIGATOR: William H. McBride CONTRACTING...TITLE AND SUBTITLE Radiation-Induced Vaccination to Breast Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-11-1-0531 5c. PROGRAM ELEMENT NUMBER

  10. Photo-induced Defects in Semiconductors

    NASA Astrophysics Data System (ADS)

    Redfield, David; Bube, Richard H.

    2006-03-01

    1. Introduction: metastable defects; 2. III-V compounds: DX2 and EL2 centers; 3. Other crystalline materials; 4. Hydrogenated amorphous silicon: properties of defects; 5. Hydrogenated amorphous silicon: photo-induced defect kinetics and processes; 6. Other amorphous semiconductors; 7. Photo-induced defect effects in devices; References; Index.

  11. Reversing Breast Cancer-Induced Immune Suppression

    DTIC Science & Technology

    2014-01-01

    4], prostaglandin E2 (PGE2) [5], IL-1β [6, 7], IL-6 [8], S100A8/A9 [9, 10], the complement component C5a [11], and endotoxin [12] induce the...by complement. Nat Immunol, 2008. 9(11): p. 1225-35. 9 12. De Wilde, V., et al., Endotoxin -induced myeloid-derived suppressor cells inhibit

  12. Reversing Breast Cancer-Induced Immune Suppression

    DTIC Science & Technology

    2014-09-01

    6, 7], IL-6 [8], S100A8/A9 [9, 10], the complement component C5a [11], and endotoxin [12] induce the accumulation of MDSC. MDSC block adaptive anti...11 12. De Wilde, V., et al., Endotoxin -induced myeloid-derived suppressor cells inhibit alloimmune responses via heme oxygenase-1. Am J

  13. Laughter-induced left bundle branch block.

    PubMed

    Chow, Grant V; Desai, Dipan; Spragg, David D; Zakaria, Sammy

    2012-10-01

    We present the case of a patient with ischemic heart disease and intermittent left bundle branch block, reproducibly induced by laughter. Following treatment of ischemia with successful deployment of a drug-eluting stent, no further episodes of inducible LBBB were seen. Transient ischemia, exacerbated by elevated intrathoracic pressure during laughter, may have contributed to onset of this phenomenon.

  14. Dynamically induced Zeeman effect in massless QED.

    PubMed

    Ferrer, Efrain J; de la Incera, Vivian

    2009-02-06

    It is shown that in nonperturbative massless QED an anomalous magnetic moment is dynamically induced by an applied magnetic field. The induced magnetic moment produces a Zeeman splitting for electrons in Landau levels higher than l=0. The expressions for the nonperturbative Lande g factor and Bohr magneton are obtained. Possible applications of this effect are outlined.

  15. Dynamically Induced Zeeman Effect in Massless QED

    SciTech Connect

    Ferrer, Efrain J.; Incera, Vivian de la

    2009-02-06

    It is shown that in nonperturbative massless QED an anomalous magnetic moment is dynamically induced by an applied magnetic field. The induced magnetic moment produces a Zeeman splitting for electrons in Landau levels higher than l=0. The expressions for the nonperturbative Lande g factor and Bohr magneton are obtained. Possible applications of this effect are outlined.

  16. Methods for determining Myc-induced apoptosis.

    PubMed

    Lu, Dan; Littlewood, Trevor D

    2013-01-01

    Although many oncoproteins promote cell growth and proliferation, some also possess the potential to induce cell death by apoptosis. Deregulated expression of the myc oncogene promotes apoptosis in both cultured cells and in some tissues in vivo. Here we describe techniques to detect Myc-induced apoptosis in vitro using flow cytometry and microscopy and in vivo using immunohistochemical staining.

  17. Minimal Mimicry: Mere Effector Matching Induces Preference

    ERIC Educational Resources Information Center

    Sparenberg, Peggy; Topolinski, Sascha; Springer, Anne; Prinz, Wolfgang

    2012-01-01

    Both mimicking and being mimicked induces preference for a target. The present experiments investigate the minimal sufficient conditions for this mimicry-preference link to occur. We argue that mere effector matching between one's own and the other person's movement is sufficient to induce preference, independent of which movement is actually…

  18. Drug-Induced Oxidative Stress and Toxicity

    PubMed Central

    Deavall, Damian G.; Martin, Elizabeth A.; Horner, Judith M.; Roberts, Ruth

    2012-01-01

    Reactive oxygen species (ROS) are a byproduct of normal metabolism and have roles in cell signaling and homeostasis. Species include oxygen radicals and reactive nonradicals. Mechanisms exist that regulate cellular levels of ROS, as their reactive nature may otherwise cause damage to key cellular components including DNA, protein, and lipid. When the cellular antioxidant capacity is exceeded, oxidative stress can result. Pleiotropic deleterious effects of oxidative stress are observed in numerous disease states and are also implicated in a variety of drug-induced toxicities. In this paper, we examine the nature of ROS-induced damage on key cellular targets of oxidative stress. We also review evidence implicating ROS in clinically relevant, drug-related side effects including doxorubicin-induced cardiac damage, azidothymidine-induced myopathy, and cisplatin-induced ototoxicity. PMID:22919381

  19. Heart failure and tachycardia-induced cardiomyopathy.

    PubMed

    Ellis, Ethan R; Josephson, Mark E

    2013-12-01

    Congestive heart failure is a major health care concern affecting almost six million Americans and an estimated 23 million people worldwide, and its prevalence is increasing with time. Long-standing tachycardia is a well-recognized cause of heart failure and left ventricular dysfunction and has led to the nomenclature, tachycardia-induced cardiomyopathy. Tachycardia-induced cardiomyopathy is generally a reversible cardiomyopathy with effective treatment of the causative arrhythmia, either with medications, surgery, or catheter ablation. Tachycardia-induced cardiomyopathy remains poorly understood and is likely under-diagnosed. A better understanding of tachycardia-induced cardiomyopathy and improved recognition of its presence in clinical practice is vital to the health of patients with this disorder. The goal of this review is to discuss the pathogenesis and clinical manifestations of tachycardia-induced cardiomyopathy, as well as approaches to its diagnosis and treatment.

  20. Induced gauge theories and W gravity

    SciTech Connect

    Schoutens, K. . Inst. for Theoretical Physics); Sevrin, A. ); van Nieuwenhuizen, P. . Theory Div. State Univ. of New York, Stony Brook, NY . Inst. for Theoretical Physics)

    1991-11-01

    We review some aspects of induced gauge theories in two dimensions. We focus on W{sub 3} gravity, paying particular attention to the treatment of the non-linearities inherent to W gravity. We show that the induced action {Gamma}{sub ind}(h,b) for chiral W{sub 3} in the c {yields} {plus minus}infinity limit is obtained from the induced action of a gauged Sl(3,R) Wess-Zumino-Witten model by imposing constraints on some of the affine currents. Subsequently we investigate the effective action, which is obtained by integrating the induced action over the gauge fields. We show perturbatively that certain subleading terms which appear in the induced action for finite c (and which are related to nonlocal terms in the Ward identifies) get canceled by similar terms due to loop corrections, and we propose an all-order result for the effective action.