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Sample records for dominik zak jrg

  1. Bulk-boundary correspondence from the intercellular Zak phase

    NASA Astrophysics Data System (ADS)

    Rhim, Jun-Won; Behrends, Jan; Bardarson, Jens H.

    2017-01-01

    The Zak phase γ , the generalization of the Berry phase to Bloch wave functions in solids, is often used to characterize inversion-symmetric one-dimensional (1D) topological insulators. Due to its dependence on the real-space origin and unit cell, however, there is an ambiguity in its use in a bulk-boundary correspondence. Here, we extract an origin-independent part of γ , the so-called intercellular Zak phase γinter, and show that it is a bulk quantity that unambiguously predicts the number of surface modes. Specifically, a neutral finite 1D tight-binding system has ns=γinter/π (mod 2) in-gap surface modes below the Fermi level if there exists a commensurate inversion-symmetric bulk unit cell. We demonstrate this in two steps: First, we verify that ±e γinter/2 π (mod e ) equals the extra charge accumulation in the surface region in a terminated system of a translationally invariant 1D insulator, while the remnant part of γ , the intracellular Zak phase γintra, corresponds to the electronic part of the bulk's unit-cell dipole moment. Second, we show that the extra charge accumulation is related to the number of surface modes when the unit cell is inversion symmetric. We study several tight-binding models to quantitatively check both the relation between the extra charge accumulation and the intercellular Zak phase, and the bulk-boundary correspondence using the intercellular Zak phase.

  2. Direct measurement of the Zak phase in topological Bloch bands

    NASA Astrophysics Data System (ADS)

    Atala, Marcos; Aidelsburger, Monika; Barreiro, Julio T.; Abanin, Dmitry; Kitagawa, Takuya; Demler, Eugene; Bloch, Immanuel

    2013-12-01

    Geometric phases that characterize the topological properties of Bloch bands play a fundamental role in the band theory of solids. Here we report on the measurement of the geometric phase acquired by cold atoms moving in one-dimensional optical lattices. Using a combination of Bloch oscillations and Ramsey interferometry, we extract the Zak phase--the Berry phase gained during the adiabatic motion of a particle across the Brillouin zone--which can be viewed as an invariant characterizing the topological properties of the band. For a dimerized lattice, which models polyacetylene, we measure a difference of the Zak phase δφZak=0.97(2)π for the two possible polyacetylene phases with different dimerization. The two dimerized phases therefore belong to different topological classes, such that for a filled band, domain walls have fractional quantum numbers. Our work establishes a new general approach for probing the topological structure of Bloch bands inoptical lattices.

  3. Gerchberg-Papoulis algorithm and the finite Zak transform

    NASA Astrophysics Data System (ADS)

    Brodzik, Andrzej K.; Tolimieri, Richard

    2000-12-01

    We propose a new, time-frequency formulation of the Gerchberg-Papoulis algorithm for extrapolation of band- limited signals. The new formulation is obtained by translating the constituent operations of the Gerchberg- Papoulis procedure, the truncation and the Fourier transform, into the language of the finite Zak transform, a time-frequency tool intimately related to the Fourier transform. We will show that the use of the Zak transform results in a significant reduction of the computational complexity of the Gerchberg-Papoulis procedure and in an increased flexibility of the algorithm.

  4. Direct Measurement of the Zak phase in Topological Bloch Bands

    NASA Astrophysics Data System (ADS)

    Aidelsburger, Monika; Atala, Marcos; Barreiro, Julio; Abanin, Dmitry; Kitagawa, Takuya; Demler, Eugene; Bloch, Immanuel

    2013-05-01

    Geometric phases that characterize the topological properties of Bloch bands play a fundamental role in the modern band theory of solids. We report on the direct measurement of the geometric phase acquired by cold atoms moving in one-dimensional optical lattices. Using a combination of Bloch oscillations and Ramsey interferometry, we extract the Zak phase--the Berry phase acquired during an adiabatic motion of a particle across the Brillouin zone--which can be viewed as an invariant characterizing the topological properties of the band. For a dimerized optical lattice, which models polyacetylene, we measure a difference of the Zak phase equal to 0.97(2) π for the two possible polyacetylene phases with different dimerization. This indicates that the two dimerized phases belong to different topological classes, such that for a filled band, domain walls have fractional quantum numbers. Our work establishes a new general approach for probing the topological structure of Bloch bands in optical lattices.

  5. Uncertainty principle for Gabor systems and the Zak transform

    SciTech Connect

    Czaja, Wojciech; Zienkiewicz, Jacek

    2006-12-15

    We show that if g(set-membership sign)L{sup 2}(R) is a generator of a Gabor orthonormal basis with the lattice ZxZ, then its Zak transform Z(g) satisfies {nabla}Z(g)(negated-set-membership sign)L{sup 2}([0,1){sup 2}). This is a generalization and extension of the Balian-Low uncertainty principle.

  6. The Banks-Zaks expansion in perturbative QCD: An update

    NASA Astrophysics Data System (ADS)

    Stevenson, P. M.

    2016-11-01

    The recent QCD calculations of the five-loop β-function and of Re+e- to O(αs4) provide one more term in the Banks-Zaks (BZ) expansion in (161 2 - nf). There is no longer any hope that the expansion could extend, even crudely, to low nf. Above nf ˜ 9, however, the results appear to be reasonably consistent from order to order.

  7. A Novel Zak Knockout Mouse with a Defective Ribotoxic Stress Response

    PubMed Central

    Jandhyala, Dakshina M.; Wong, John; Mantis, Nicholas J.; Magun, Bruce E.; Leong, John M.; Thorpe, Cheleste M.

    2016-01-01

    Ricin activates the proinflammatory ribotoxic stress response through the mitogen activated protein 3 kinase (MAP3K) ZAK, resulting in activation of mitogen activated protein kinases (MAPKs) p38 and JNK1/2. We had a novel zak−/− mouse generated to study the role of ZAK signaling in vivo during ricin intoxication. To characterize this murine strain, we intoxicated zak−/− and zak+/+ bone marrow–derived murine macrophages with ricin, measured p38 and JNK1/2 activation by Western blot, and measured zak, c-jun, and cxcl-1 expression by qRT-PCR. To determine whether zak−/− mice differed from wild-type mice in their in vivo response to ricin, we performed oral ricin intoxication experiments with zak+/+ and zak−/− mice, using blinded histopathology scoring of duodenal tissue sections to determine differences in tissue damage. Unlike macrophages derived from zak+/+ mice, those derived from the novel zak−/− strain fail to activate p38 and JNK1/2 and have decreased c-jun and cxcl-1 expression following ricin intoxication. Furthermore, compared with zak+/+ mice, zak−/− mice have decreased duodenal damage following in vivo ricin challenge. zak−/− mice demonstrate a distinct ribotoxic stress–associated phenotype in response to ricin and therefore provide a new animal model for in vivo studies of ZAK signaling. PMID:27598200

  8. A Requirement for ZAK Kinase Activity in Canonical TGF-β Signaling.

    PubMed

    Nyati, Shyam; Chator, Areeb; Schinske, Katerina; Gregg, Brandon S; Ross, Brian Dale; Rehemtulla, Alnawaz

    2016-12-01

    The sterile alpha motif and leucine zipper containing kinase ZAK (AZK, MLT, MLK7), is a MAPK-kinase kinase (MKKK). Like most MAPKKKs which are known to activate the c-Jun. amino-terminal kinase (JNK) pathway, ZAK has been shown to participate in the transduction of Transforming growth factor-β (TGF-β)-mediated non-canonical signaling. A role for ZAK in SMAD-dependent, canonical TGF-β signaling has not been previously appreciated. Using a combination of functional genomics and biochemical techniques, we demonstrate that ZAK regulates canonical TGFβRI/II signaling in lung and breast cancer cell lines and may serve as a key node in the regulation of TGFBR kinase activity. Remarkably, we demonstrate that siRNA mediated depletion of ZAK strongly inhibited TGF-β dependent SMAD2/3 activation and subsequent promoter activation (SMAD binding element driven luciferase expression; SBE4-Luc). A ZAK specific inhibitor (DHP-2), dose-dependently activated the bioluminescent TGFBR-kinase activity reporter (BTR), blocked TGF-β induced SMAD2/3 phosphorylation and SBE4-Luc activation and cancer cell-invasion. In aggregate, these findings identify a novel role for the ZAK kinase in canonical TGF-β signaling and an invasive cancer cell phenotype thus providing a novel target for TGF-β inhibition.

  9. Topological end states and Zak phase of rectangular armchair ribbon

    NASA Astrophysics Data System (ADS)

    Jeong, Y. H.; Eric Yang, S.-R.

    2017-10-01

    We consider the end states of a half-filled rectangular armchair graphene ribbon (RAGR) in a staggered potential. Taking electron-electron interactions into account we find that, as the strength of the staggered potential varies, three types of couplings between the end states can occur: antiferromagnetic without or with spin splitting, and paramagnetic without spin-splitting. We find that a spin-splitting is present only in the staggered potential region 0 < Δ <Δc. The transition from the antiferromagnetic state at Δ = 0 to the paramagnetic state goes through an intermediate spin-split antiferromagnetic state, and this spin-splitting disappears suddenly at Δc. For small and large values of Δ the end charge of a RAGR can be connected to the Zak phase of the periodic armchair graphene ribbon (PARG) with the same width, and it varies continuously as the strength of the potential changes.

  10. Registration of Zak ERA8 soft white spring wheat germplasm with enhanced response to ABA and increased seed dormancy

    USDA-ARS?s Scientific Manuscript database

    ZakERA8 is a unique mutant line selected from mutagenized soft white spring 'Zak' that has increased seed dormancy as a result of enhanced responsiveness to the plant hormone abscisic acid (ABA) during germination. This germplasm was developed by USDA-ARS, Pullman, WA in collaboration with Washingt...

  11. Evolution of Zakłodzie enstatite meteorite - insight from TEM analyses

    NASA Astrophysics Data System (ADS)

    Krzesinska, A.; Wirth, R.; Kusiak, M. A.

    2015-10-01

    The Zakłodzie meteorite is an achondritic-like rock with enstatite chondrite parentage [1,2,3]. Its texture indicative for complicated thermal history and various processes were proposed to account for this [1,2,3]. Based on the mineral composition it was concluded that the rock represents EL7 enstatite chondrite [1]. Twinned enstatite and zonal feldspar crystals in Zakłodzie were interpreted as formed by impact melting and rapid crystallization [2]. On the other hand, cumulate structure was considered to result from igneous processes and slow cooling of the meteorite [3]. The aim of presented study was to define whether Zakłodzie formed by shock event on chondritic parent body or by slow cooling from high temperatures typical for achondritic meteorites.

  12. Detection of Zak phases and topological invariants in a chiral quantum walk of twisted photons

    NASA Astrophysics Data System (ADS)

    Cardano, Filippo; D'Errico, Alessio; Dauphin, Alexandre; Maffei, Maria; Piccirillo, Bruno; de Lisio, Corrado; de Filippis, Giulio; Cataudella, Vittorio; Santamato, Enrico; Marrucci, Lorenzo; Lewenstein, Maciej; Massignan, Pietro

    2017-06-01

    Topological insulators are fascinating states of matter exhibiting protected edge states and robust quantized features in their bulk. Here we propose and validate experimentally a method to detect topological properties in the bulk of one-dimensional chiral systems. We first introduce the mean chiral displacement, an observable that rapidly approaches a value proportional to the Zak phase during the free evolution of the system. Then we measure the Zak phase in a photonic quantum walk of twisted photons, by observing the mean chiral displacement in its bulk. Next, we measure the Zak phase in an alternative, inequivalent timeframe and combine the two windings to characterize the full phase diagram of this Floquet system. Finally, we prove the robustness of the measure by introducing dynamical disorder in the system. This detection method is extremely general and readily applicable to all present one-dimensional platforms simulating static or Floquet chiral systems.

  13. Zak phase induced multiband waveguide by two-dimensional photonic crystals.

    PubMed

    Yang, Yuting; Xu, Tao; Xu, Yun Fei; Hang, Zhi Hong

    2017-08-15

    Interface states in photonic crystals provide efficient approaches to control the flow of light. Photonic Zak phase determines the bulk band properties of photonic crystals, and, by assembling two photonic crystals with different bulk band properties together, deterministic interface states can be realized. By translating each unit cell of a photonic crystal by half the lattice constant, another photonic crystal with identical common gaps but a different Zak phase at each photonic band can be created. By assembling these two photonic crystals together, multiband waveguide can thus be easily created and then experimentally characterized. Our experimental results have good agreement with numerical simulations, and the propagation properties of these measured interface states indicate that this new type of interface state will be a good candidate for future applications of optical communications.

  14. Integrated exome and transcriptome sequencing reveals ZAK isoform usage in gastric cancer

    PubMed Central

    Liu, Jinfeng; McCleland, Mark; Stawiski, Eric W.; Gnad, Florian; Mayba, Oleg; Haverty, Peter M.; Durinck, Steffen; Chen, Ying-Jiun; Klijn, Christiaan; Jhunjhunwala, Suchit; Lawrence, Michael; Liu, Hanbin; Wan, Yinan; Chopra, Vivek; Yaylaoglu, Murat B.; Yuan, Wenlin; Ha, Connie; Gilbert, Houston N.; Reeder, Jens; Pau, Gregoire; Stinson, Jeremy; Stern, Howard M.; Manning, Gerard; Wu, Thomas D.; Neve, Richard M.; de Sauvage, Frederic J.; Modrusan, Zora; Seshagiri, Somasekar; Firestein, Ron; Zhang, Zemin

    2014-01-01

    Gastric cancer is the second leading cause of worldwide cancer mortality, yet the underlying genomic alterations remain poorly understood. Here we perform exome and transcriptome sequencing and SNP array assays to characterize 51 primary gastric tumours and 32 cell lines. Meta-analysis of exome data and previously published data sets reveals 24 significantly mutated genes in microsatellite stable (MSS) tumours and 16 in microsatellite instable (MSI) tumours. Over half the patients in our collection could potentially benefit from targeted therapies. We identify 55 splice site mutations accompanied by aberrant splicing products, in addition to mutation-independent differential isoform usage in tumours. ZAK kinase isoform TV1 is preferentially upregulated in gastric tumours and cell lines relative to normal samples. This pattern is also observed in colorectal, bladder and breast cancers. Overexpression of this particular isoform activates multiple cancer-related transcription factor reporters, while depletion of ZAK in gastric cell lines inhibits proliferation. These results reveal the spectrum of genomic and transcriptomic alterations in gastric cancer, and identify isoform-specific oncogenic properties of ZAK. PMID:24807215

  15. Direct Manifestation of the Band Topology via the Zak Shift of the Wannier-Stark Ladder

    NASA Astrophysics Data System (ADS)

    Lee, Woo-Ram; Park, Kwon

    2015-03-01

    Topological phases of matter have been topics of intense interest in modern condensed matter physics. Numerous efforts have been devoted to investigating various exotic properties of materials with non-trivial band topology. The dissipationless transport via gapless helical edge or surface states is one of the defining properties of such materials, which, however, has been very difficult to realize in experiment due to various backscattering sources induced in the sample boundaries. In this work, we show that there is a fundamental connection between the non-trivial topology of the band structure and the Zak shift of the Wannier-Stark ladder emerging under a static electric field. As an application of this connection, we propose a novel spectroscopic method to directly manifest the band topology by counting the winding number of the Zak phase across the first Brillouin zone, which is shown to be robust against electron-impurity scattering. The authors thank KIAS Center for Advanced Computation (CAC) for providing computing resources.

  16. QCD fixed points: Banks-Zaks scenario or dynamical gluon mass generation?

    NASA Astrophysics Data System (ADS)

    Gomez, J. D.; Natale, A. A.

    2017-01-01

    Fixed points in QCD can appear when the number of quark flavors (Nf) is increased above a certain critical value as proposed by Banks and Zaks (BZ). There is also the possibility that QCD possess an effective charge indicating an infrared frozen coupling constant. In particular, an infrared frozen coupling associated to dynamical gluon mass (DGM) generation does lead to a fixed point even for a small number of quarks. We compare the BZ and DGM mechanisms, their β functions and fixed points, and within the approximations of this work, which rely basically on extrapolations of the dynamical gluon masses at large Nf, we verify that between Nf = 8 and Nf = 12 both cases exhibit fixed points at similar coupling constant values (g∗). We argue that the states of minimum vacuum energy, as a function of the coupling constant up to g∗ and for several Nf values, are related to the dynamical gluon mass generation mechanism.

  17. Sorafenib suppresses JNK-dependent apoptosis through inhibition of ZAK kinase

    PubMed Central

    Vin, Harina; Ching, Grace; Ojeda, Sandra S.; Adelmann, Charles H.; Chitsazzadeh, Vida; Dwyer, David W.; Ma, Haiching; Ehrenreiter, Karin; Baccarini, Manuela; Ruggieri, Rosamaria; Curry, Jonathan L.; Ciurea, Ana M.; Duvic, Madeleine; Busaidy, Naifa L.; Tannir, Nizar M.; Tsai, Kenneth Y.

    2015-01-01

    Sorafenib is FDA-approved for the treatment of renal cell carcinoma and hepatocellular carcinoma and has been combined with numerous other targeted therapies and chemotherapies in the treatment of many cancers. Unfortunately, as with other RAF inhibitors, patients treated with sorafenib have a 5–10% rate of developing cutaneous squamous cell carcinoma/keratoacanthomas. Paradoxical activation of ERK in BRAF-wild-type cells has been implicated in RAF-inhibitor-induced cSCC. Here we report that sorafenib suppresses UV-induced apoptosis specifically by inhibiting JNK activation through the off-target inhibition of ZAK kinase. Our results implicate suppression of JNK signaling, independent of the ERK pathway, as an additional mechanism of adverse effects of sorafenib. This has broad implications for combination therapies using sorafenib with other modalities that induce apoptosis. PMID:24170769

  18. Exome sequencing and CRISPR/Cas genome editing identify mutations of ZAK as a cause of limb defects in humans and mice.

    PubMed

    Spielmann, Malte; Kakar, Naseebullah; Tayebi, Naeimeh; Leettola, Catherine; Nürnberg, Gudrun; Sowada, Nadine; Lupiáñez, Darío G; Harabula, Izabela; Flöttmann, Ricarda; Horn, Denise; Chan, Wing Lee; Wittler, Lars; Yilmaz, Rüstem; Altmüller, Janine; Thiele, Holger; van Bokhoven, Hans; Schwartz, Charles E; Nürnberg, Peter; Bowie, James U; Ahmad, Jamil; Kubisch, Christian; Mundlos, Stefan; Borck, Guntram

    2016-02-01

    The CRISPR/Cas technology enables targeted genome editing and the rapid generation of transgenic animal models for the study of human genetic disorders. Here we describe an autosomal recessive human disease in two unrelated families characterized by a split-foot defect, nail abnormalities of the hands, and hearing loss, due to mutations disrupting the SAM domain of the protein kinase ZAK. ZAK is a member of the MAPKKK family with no known role in limb development. We show that Zak is expressed in the developing limbs and that a CRISPR/Cas-mediated knockout of the two Zak isoforms is embryonically lethal in mice. In contrast, a deletion of the SAM domain induces a complex hindlimb defect associated with down-regulation of Trp63, a known split-hand/split-foot malformation disease gene. Our results identify ZAK as a key player in mammalian limb patterning and demonstrate the rapid utility of CRISPR/Cas genome editing to assign causality to human mutations in the mouse in <10 wk.

  19. Exome sequencing and CRISPR/Cas genome editing identify mutations of ZAK as a cause of limb defects in humans and mice

    PubMed Central

    Spielmann, Malte; Kakar, Naseebullah; Tayebi, Naeimeh; Leettola, Catherine; Nürnberg, Gudrun; Sowada, Nadine; Lupiáñez, Darío G.; Harabula, Izabela; Flöttmann, Ricarda; Horn, Denise; Chan, Wing Lee; Wittler, Lars; Yilmaz, Rüstem; Altmüller, Janine; Thiele, Holger; van Bokhoven, Hans; Schwartz, Charles E.; Nürnberg, Peter; Bowie, James U.; Ahmad, Jamil; Kubisch, Christian; Mundlos, Stefan; Borck, Guntram

    2016-01-01

    The CRISPR/Cas technology enables targeted genome editing and the rapid generation of transgenic animal models for the study of human genetic disorders. Here we describe an autosomal recessive human disease in two unrelated families characterized by a split-foot defect, nail abnormalities of the hands, and hearing loss, due to mutations disrupting the SAM domain of the protein kinase ZAK. ZAK is a member of the MAPKKK family with no known role in limb development. We show that Zak is expressed in the developing limbs and that a CRISPR/Cas-mediated knockout of the two Zak isoforms is embryonically lethal in mice. In contrast, a deletion of the SAM domain induces a complex hindlimb defect associated with down-regulation of Trp63, a known split-hand/split-foot malformation disease gene. Our results identify ZAK as a key player in mammalian limb patterning and demonstrate the rapid utility of CRISPR/Cas genome editing to assign causality to human mutations in the mouse in <10 wk. PMID:26755636

  20. ZAK induces MMP-2 activity via JNK/p38 signals and reduces MMP-9 activity by increasing TIMP-1/2 expression in H9c2 cardiomyoblast cells.

    PubMed

    Cheng, Yi-Chang; Kuo, Wei-Wen; Wu, Hsi-Chin; Lai, Tung-Yuan; Wu, Chun-Hsien; Hwang, Jin-Ming; Wang, Wen-Hong; Tsai, Fuu-Jen; Yang, Jaw-Ji; Huang, Chih-Yang; Chu, Chun-Hsien

    2009-05-01

    Leucine-zipper and sterile-alpha motif kinase (ZAK) is the key intra-cellular mediator protein in cardiomyocyte hypertrophy induction by transforming growth factor beta 1 (TGF-beta1) which has also been identified as a profibrotic cytokine involved in cardiac fibrosis progression. We hypothesized whether ZAK over-expression causes cardiac scar formation due to the extra-cellular matrix (ECM) degraded enzyme regulation in this paper. Using immuno-histochemical analysis of the human cardiovascular tissue array, we found a positively significant association between ZAK over-expression and myocardial scars. ZAK over-expression in H9c2 cardiomyoblast cells increases the metalloproteinase tissue inhibitor 1/2 (TIMP-1/2) protein level, which reduces matria metalloproteinase-9 (MMP-9) activity and also activates c-JNK N-terminal kinase 1/2 (JNK1/2) and p38 signaling, which induces MMP-2, possibly resulting in cardiac fibrosis. Taken together, ZAK activity inhibition may be a good strategy to prevent the cardiac fibrosis progression.

  1. Identification of the ZAK-MKK4-JNK-TGFβ signaling pathway as a molecular target for novel synthetic iminoquinone anticancer compound BA-TPQ.

    PubMed

    Chen, Deng; Wang, Wei; Qin, Jiang-Jiang; Wang, Ming-Hai; Murugesan, Srinivasan; Nadkarni, Dwayaja H; Velu, Sadanandan E; Wang, Hui; Zhang, Ruiwen

    2013-07-01

    Identification and validation of molecular targets are considered as key elements in new drug discovery and development. We have recently demonstrated that a novel synthetic iminoquinone analog, termed [7-(benzylamino)- 1,3,4,8-tetrahydropyrrolo [4,3, 2-de]quinolin-8(1H)-one] (BA-TPQ), has significant anti-breast cancer activity both in vitro and in vivo, but the underlying molecular mechanisms are not fully understood. Herein, we report the molecular studies for BA-TPQ's effects on JNK and its upstream and downstream signaling pathways. The compound up-regulates the JNK protein levels by increasing its phosphorylation and decreasing its polyubiquitination-mediated degradation. It activates ZAK at the MAPKKK level and MKK4 at the MAPKK level. It also up-regulates the TGFβ2 mRNA level, which can be abolished by the JNK-specific inhibitor SP600125, but not TGFβ pathway-specific inhibitor SD-208, indicating that both JNK and TGFβ signaling pathways are activated by BA-TPQ and that the JNK pathway activation precedes TGFβ activation. The pro-apoptotic and anti-growth effects of BA-TPQ are significantly blocked by both the JNK and TGFβ pathway inhibitors. In addition, BA-TPQ activates the ZAK-MKK4-JNK pathway in MCF7 cells, but not normal MCF10A cells, demonstrating its cancer-specific activities. In conclusion, our results demonstrate that BA-TPQ activates the ZAK-MKK4-JNK-TGFβ signaling cascade as a molecular target for its anticancer activity.

  2. The Armadillo Repeat Gene ZAK IXIK Promotes Arabidopsis Early Embryo and Endosperm Development through a Distinctive Gametophytic Maternal Effect[C][W][OA

    PubMed Central

    Ngo, Quy A.; Baroux, Celia; Guthörl, Daniela; Mozerov, Peter; Collinge, Margaret A.; Sundaresan, Venkatesan; Grossniklaus, Ueli

    2012-01-01

    The proper balance of parental genomic contributions to the fertilized embryo and endosperm is essential for their normal growth and development. The characterization of many gametophytic maternal effect (GME) mutants affecting seed development indicates that there are certain classes of genes with a predominant maternal contribution. We present a detailed analysis of the GME mutant zak ixik (zix), which displays delayed and arrested growth at the earliest stages of embryo and endosperm development. ZIX encodes an Armadillo repeat (Arm) protein highly conserved across eukaryotes. Expression studies revealed that ZIX manifests a GME through preferential maternal expression in the early embryo and endosperm. This parent-of-origin–dependent expression is regulated by neither the histone and DNA methylation nor the DNA demethylation pathways known to regulate some other GME mutants. The ZIX protein is localized in the cytoplasm and nucleus of cells in reproductive tissues and actively dividing root zones. The maternal ZIX allele is required for the maternal expression of MINISEED3. Collectively, our results reveal a reproductive function of plant Arm proteins in promoting early seed growth, which is achieved through a distinct GME of ZIX that involves mechanisms for maternal allele-specific expression that are independent of the well-established pathways. PMID:23064319

  3. [Sanitation of the health service centre in Warsaw (Samodzielny Zespół Publicznych Zakładów Lecznictwa Otwartego Warszawa-Mokotów). Financial and economic analysis].

    PubMed

    Buczak-Stec, Elzbieta

    2010-01-01

    The aim of the financial and economic analysis, conducted in March 2010, was to identify all significant factors that had a positive influence on the restructuring process in the health service centre (Samodzielny Zespół Publicznych Zakładów Lecznictwa Otwartego Warszawa--Mokotów) in Warsaw. Within the framework of the analysis, financial data form time period 1999-2009 were analyzed. Also the managing director and financial director were interviewed. Taking into consideration research results it can be stated that not a single factor but a collection of the purposeful efforts influenced the improvement of the health service centre condition. Apart from received public help, the most significant factors include: rational restructuring process, managing of personnel development, professionally managed financial department, cooperation between departments, good internal communication and use of modern management techniques.

  4. Antimicrobial potential of phylogenetically unique actinomycete, Streptomyces sp. JRG-04 from marine origin.

    PubMed

    Govindarajan, Ganesan; Satheeja Santhi, Velayudhan; Jebakumar, Solomon Robinson David

    2014-11-01

    Due to the emergence of severe infectious diseases and thriving antibiotic resistance, there is a need to explore microbial-derived bioactive secondary metabolites from unexplored regions. Present study deals with a mangrove estuary derived strain of Streptomyces sp. with potent antimicrobial activity against various pathogens, including methicillin resistant Staphylococcus aureus. Bioactive compound was effective even at low MIC level, damages the membrane of methicillin resistant S. aureus and causes cell death, however it has no cytotoxic effect on H9C2 cells. 16S rRNA shared 99.5% sequence similarity to Streptomyces longispororuber. Optimum biomass and antimicrobial compound production were observed in production medium supplemented with 1.0% maltose and 0.5% yeast extract. The active compound purified from the chloroform extract of the cell-free supernatant was studied by FT-IR, 1H NMR, 13C NMR and LC ESI-MS and identified as aromatic polyketide. β-ketosynthase (KS) domain of the Streptomyces strain revealed 93.2% sequence similarity to the benzoisochromanequinone, an actinorhodin biosynthetic gene cluster of Streptomyces coelicolor A3(2). However, the region synthesizing the secondary metabolite produced by the S. longispororuber was not related to the KS domain of the strain, due to the phenomenon of horizontal gene transfer over the period of evolutionary process, thus generating metabolic compound diversity.

  5. The Multiplicative Zak Transform, Dimension Reduction, and Wavelet Analysis of LIDAR Data

    DTIC Science & Technology

    2010-01-01

    Regina has experienced the beastly moods and the frequent mismanagement of priorities that I have displayed and she has powered through them still...conceptual difference allows for a great deal of flexibility when it comes time to classify the data, as frames are essentially designable . 1.1.3...paper (such as the inverse of Theorem 7) have been worked out, this will provide a simple mechanism to create families of wavelet frames with designed

  6. Enhanced Bone Formation in Segmental Defects with BMP2 in a Biologically Relevant Molecular Context

    DTIC Science & Technology

    2016-10-16

    period? One previously active grant ended. This grant had provided salary support for both PI (Dominik Haudenschild) and co-investigator ( Jasper ...and actin assembly of C2C12 cells Authors: Victoria Tran1, Arpad Karsai1, Michael Fong2, Evgeny Ogorodnik1, Jasper Yip2, Dominik Haudenschild*2

  7. A Hierarchical Preference Voting System for Mining Method Selection Problem / Wykorzystanie Systemu Głosowania Zakładający Hierarchię Preferencji Przy Wyborze Odpowiedniej Metody Wybierania

    NASA Astrophysics Data System (ADS)

    Nourali, Hamidreza; Nourali, Saeid; Ataei, Mohammad; Imanipour, Narges

    2012-12-01

    To apply decision making theory for Mining Method Selection (MMS) problem, researchers have faced two difficulties in recent years: (i) calculation of relative weight for each criterion, (ii) uncertainty in judgment for decision makers. In order to avoid these difficulties, we apply a Hierarchical Preference Voting System (HPVS) for MMS problem that uses a Data Envelopment Analysis (DEA) model to produce weights associated with each ranking place. The presented method solves the problem in two stages. In the first stage, weights of criteria are calculated and at the second stage, alternatives are ranked with respect to all criteria. A simple case study has also been presented to illustrate the competence of this method. The results show that this approach reduces some difficulties of previous methods and could be applied simply in group decision making with too many decision makers and criteria. Also, regarding to application of a mathematical model, subjectivity is reduced and outcomes are more reliable.

  8. Defeating Insurgencies with Minimal Force Ratios

    DTIC Science & Technology

    2013-06-14

    Before his killing he penned an open letter to President Carter, asking for the US to stop supporting the JRG and call for peace.47 At his funeral...in an enemy-centric fashion. Others, most notably demonstrated by COL (ret.) Tunnell’s open letter to the Secretary of the Army, argue the US should

  9. To Make a Male: What Does It Take?

    ERIC Educational Resources Information Center

    Elfer, Jane; Lee, Anthony

    2009-01-01

    This article presents a case study of a year of psychotherapeutic work by a female and male therapist with a 14-year-old boy born with ambiguous genitalia. His mother was also present in the sessions at the request of Zak. We describe the early trauma surrounding Zak's birth and the subsequent desertion of a violent father. We present the…

  10. To Make a Male: What Does It Take?

    ERIC Educational Resources Information Center

    Elfer, Jane; Lee, Anthony

    2009-01-01

    This article presents a case study of a year of psychotherapeutic work by a female and male therapist with a 14-year-old boy born with ambiguous genitalia. His mother was also present in the sessions at the request of Zak. We describe the early trauma surrounding Zak's birth and the subsequent desertion of a violent father. We present the…

  11. JPRS Report, Science & Technology, Japan, High Temperature Materials

    DTIC Science & Technology

    1990-11-09

    French, K., "Ceramic Materials and Components for Engines," Las Vegas, Nevada, USA, 1988, pp 1397-1406. 6. Mutsudy, B.C., INDUSTRIAL RESEARCH AND... Industries Symposium, Manuscripts for Fine Ceramics, 91, Nagoya, 1986. 10. Thomas, M.S. and Evans, J.R.G., BR. CERAM. TRANS. J., Vol 87, 1988, pp 22...Model OPowder packing (2 Binder infiltration. ® Refrigeracion 75~ ... a Ta Master Model drawing powder powder+binder powder.binder S@Casting 0DMold

  12. Delivery of MISAR Algorithms

    DTIC Science & Technology

    2006-03-07

    results of this denoising method. Figure 4 displays the noise-free cyclic echo which is the sum of 5 cyclically shifted chirps with non-negative...products real part imaginary part Simplest denoising in Zak domain is used to estimate the reflectivity kernel coefficients in the presence of noise. The...results of denoising . Zak transform parameters are L = 40 and K = 40. Setting L = 20, we have another estimate for the first 20 coefficients of the

  13. Biographical sketch: Franz König, MD 1832-1910.

    PubMed

    Brand, Richard A

    2013-04-01

    This biographical sketch on Franz König corresponds to the historic text, The Classic: Ueber freie Körper in den Gelenken [On loose bodies in the joint] (1887), available at DOI 10.1007/s11999-013-2824-y (Translated by Drs. Richard A. Brand and Christian-Dominik Peterlein).

  14. Biography Today: Sports Series. Profiles of People of Interest to Young Readers. Volume 3, 1999.

    ERIC Educational Resources Information Center

    Harris, Laurie Lanzen, Ed.; Abbey, Cherie D., Ed.

    This third volume is part of a series of biographies that profile individuals of interest to young people over the age of 9 years. The entries in this volume include Joe Dumars, basketball; Jim Harbaugh, football; Dominik Hasek, hockey; Michelle Kwan, figure skating; Rebecca Lobo, basketball; Greg Maddux, baseball; Fatuma Roba, marathon running;…

  15. The dynamics of HTLV-I and the CTL response.

    PubMed

    Wodarz, D; Nowak, M A; Bangham, C R

    1999-05-01

    Dominik Wodarz and colleagues describe a mathematical model for the in vivo dynamics of human T-cell leukaemia virus type 1 (HTLV-I) infection and the virus-specific cytotoxic T lymphocyte response. They show that a high rate of viral replication is consistent with the relative sequence invariance of HTLV-I and might be necessary to maintain a persistent infection.

  16. Surface to bulk Fermi arcs via Weyl nodes as topological defects

    PubMed Central

    Kim, Kun Woo; Lee, Woo-Ram; Kim, Yong Baek; Park, Kwon

    2016-01-01

    A hallmark of Weyl semimetal is the existence of surface Fermi arcs. An intriguing question is what determines the connectivity of surface Fermi arcs, when multiple pairs of Weyl nodes are present. To answer this question, we show that the locations of surface Fermi arcs are predominantly determined by the condition that the Zak phase integrated along the normal-to-surface direction is . The Zak phase can reveal the peculiar topological structure of Weyl semimetal directly in the bulk. Here, we show that the winding of the Zak phase around each projected Weyl node manifests itself as a topological defect of the Wannier–Stark ladder, energy eigenstates under an electric field. Remarkably, this leads to bulk Fermi arcs, open-line segments in the bulk spectra. Bulk Fermi arcs should exist in conjunction with surface counterparts to conserve the Weyl fermion number under an electric field, which is supported by explicit numerical evidence. PMID:27845342

  17. Surface to bulk Fermi arcs via Weyl nodes as topological defects

    NASA Astrophysics Data System (ADS)

    Kim, Kun Woo; Lee, Woo-Ram; Kim, Yong Baek; Park, Kwon

    2016-11-01

    A hallmark of Weyl semimetal is the existence of surface Fermi arcs. An intriguing question is what determines the connectivity of surface Fermi arcs, when multiple pairs of Weyl nodes are present. To answer this question, we show that the locations of surface Fermi arcs are predominantly determined by the condition that the Zak phase integrated along the normal-to-surface direction is . The Zak phase can reveal the peculiar topological structure of Weyl semimetal directly in the bulk. Here, we show that the winding of the Zak phase around each projected Weyl node manifests itself as a topological defect of the Wannier-Stark ladder, energy eigenstates under an electric field. Remarkably, this leads to bulk Fermi arcs, open-line segments in the bulk spectra. Bulk Fermi arcs should exist in conjunction with surface counterparts to conserve the Weyl fermion number under an electric field, which is supported by explicit numerical evidence.

  18. Early Intervention with cdk9 Inhibitors to Prevent Post-Traumatic Osteoarthritis

    DTIC Science & Technology

    2014-10-01

    34 seminar series held by the Radiology Department of UC Davis. o 2013 June 20, “Early Response to Joint Injury”, University of California Davis...Department of Orthopaedic Surgery Research Symposium, Lawrence J. Ellison Musculoskeletal Research Center. Page 11 o 2013 October 15, “Early Response to...Arthritis and Musculoskeletal and Skin Diseases grant R21-AR- 063348 to Dr. Haudenschild). 1Jasper H. N. Yik, PhD, Blaine A. Christiansen, PhD, Dominik

  19. Improving the Diagnostic Specificity of CT for Early Detection of Lung Cancer: 4D CT-Based Pulmonary Nodule Elastometry

    DTIC Science & Technology

    2013-08-01

    registration with vessel bifurcations. International Conference of Computer Assisted Radiology and Surgery (CARS); June. Berlin, Germany2007. 3... Implanting the benign mode (carbon nanotubes) at an exact pre-determined site within the lung. • Demonstrate that the volume of the lesion/tumor...have been selected for oral presentation: 1. Mohammadreza Negahdar, Billy W Loo, Maximilian Diehn, Lu Tian, Dominik Fleischmann, and Peter G Maxim

  20. Discovery and follow-up of 51 Eri b, a directly-imaged Jupiter-like exoplanet and status of the GPIES campaign.

    NASA Astrophysics Data System (ADS)

    Marchis, Franck; Nielsen, Eric L.; Blunt, Sarah; Rameau, Julien; Barman, Travis; De Rosa, Robert J.; Konopacky, Quinn; Marley, Mark S.; Marois, Christian; Pueyo, Laurent; Rajan, Abhijith; Wang, Jason J.; Macintosh, Bruce; Graham, James R.

    2015-11-01

    Directly detecting thermal emission from young extrasolar planets allows measurement of their atmospheric composition, gravity and luminosity, which is influenced by their formation mechanism. The Gemini Planet Imager Exoplanet Survey (GPIES) is targeting 600 young, nearby stars using the GPI instrument. The star 51 Eridani (51 Eri) was chosen as an early target for the survey due to its youth and proximity. We discovered a planet orbiting the ~20 Myr-old beta Pic moving group member star 51 Eridani at a projected separation of 13 astronomical units (Macintosh et al. Science, 2015). Near-infrared observations show a spectrum with strong methane and water vapor absorption. Modeling of the spectra and photometry yields a luminosity of L/L⦿=1.6-4.0 × 10-6 and an effective temperature of 600-750 K. For this age and luminosity, “hot-start” formation models indicate a mass twice that of Jupiter. This planet also has a sufficiently low luminosity to be the first directly imaged exoplanet to be consistent with the 'cold-start' core accretion process that may have formed Jupiter.Follow-up observations scheduled in Fall 2015 will allow us to constrain the orbit of this exoplanet and derive more information on its atmosphere. These new data, and additional interesting targets, will be presented and discussed.Supported by grants from the National Science Foundation AST-1411868 (BM, KF, JP, AR), AST-0909188 and 1313718 (JRG, PK, RDR, JW), AST-1313718 (MPF and GD) and AST-1405505. Supported by grants from NASA NNX14AJ80G (BM, FM, EN, MP), NNH15AZ591 (DS, MM), NNX15AD95G (JRG, PK), NNX11AD21G (JRG, PK) and NNH11ZDA001N (SM, RP). JR, RD and DL acknowledge support from the Fonds de recherche du Quebec. Portions of this work were performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  1. Response to Rollock

    ERIC Educational Resources Information Center

    Woods, Ruth

    2008-01-01

    This article presents the author's response to Nicola Rollock's critique on the author's paper in which the author has argued that ethnographic data should be more widely used in psychology (Woods 2005, 2007b). Rollock argues that the paper neglects Zak's level of educational achievement, and fails to critically interrogate his teachers' actions…

  2. Adaptation algorithms for 2-D feedforward neural networks.

    PubMed

    Kaczorek, T

    1995-01-01

    The generalized weight adaptation algorithms presented by J.G. Kuschewski et al. (1993) and by S.H. Zak and H.J. Sira-Ramirez (1990) are extended for 2-D madaline and 2-D two-layer feedforward neural nets (FNNs).

  3. Low-Rate Discharge of Various Electrochemical Batteries for Use with Oceanographic Instruments.

    DTIC Science & Technology

    1985-04-01

    Electrochemical Society, Inc., Pennington, N.J.: Abraham , K. M. and R. M. Mank. Some safety related chemistry of Li/SOClz cells Babai, M., and U. Zak...lithium-sulfur dioxide battery systems Hazkany, E. Peled and B. Raz. Primary cells - a forecast of performance Johnson, L. J. and A. H. Willis. User

  4. 75 FR 43807 - Airworthiness Directives; Zaklad Szybo wcowy “Jeżów” Henryk Mynarski Model PW-6U Sailplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... ``Je w'' Henryk Mynarski Model PW-6U Sailplanes AGENCY: Federal Aviation Administration (FAA), DOT... information by examining the MCAI in the AD docket. Relevant Service Information Zak ad Szybowcowy ``Je w... Szybowcowy ``Je w'' Henryk Mynarski: Amendment 39-16373; Docket No. FAA-2010-0729; Directorate...

  5. The 2016 Frontiers in Medicinal Chemistry Conference in Bonn.

    PubMed

    Müller, Christa E; Thimm, Dominik; Baringhaus, Karl-Heinz

    2017-01-05

    Pushing the frontiers of medicinal chemistry: Christa Müller, Dominik Thimm, and Karl-Heinz Baringhaus look back at the events of the 2016 Frontiers in Medicinal Chemistry (FiMC) Conference held in Bonn, Germany. The report highlights the themes & talks in the annual conference hosted by the Joint Division of Medicinal Chemistry of the German Pharmaceutical Society (DPhG) and German Chemical Society (GDCh). It is also an invitation to the 2017 conference in Bern, Switzerland this February 12-15.

  6. Topological Dirac nodal lines and surface charges in fcc alkaline earth metals

    NASA Astrophysics Data System (ADS)

    Hirayama, Motoaki; Okugawa, Ryo; Miyake, Takashi; Murakami, Shuichi

    2017-01-01

    In nodal-line semimetals, the gaps close along loops in k space, which are not at high-symmetry points. Typical mechanisms for the emergence of nodal lines involve mirror symmetry and the π Berry phase. Here we show via ab initio calculations that fcc calcium (Ca), strontium (Sr) and ytterbium (Yb) have topological nodal lines with the π Berry phase near the Fermi level, when spin-orbit interaction is neglected. In particular, Ca becomes a nodal-line semimetal at high pressure. Owing to nodal lines, the Zak phase becomes either π or 0, depending on the wavevector k, and the π Zak phase leads to surface polarization charge. Carriers eventually screen it, leaving behind large surface dipoles. In materials with nodal lines, both the large surface polarization charge and the emergent drumhead surface states enhance Rashba splitting when heavy adatoms are present, as we have shown to occur in Bi/Sr(111) and in Bi/Ag(111).

  7. Topological Dirac nodal lines and surface charges in fcc alkaline earth metals.

    PubMed

    Hirayama, Motoaki; Okugawa, Ryo; Miyake, Takashi; Murakami, Shuichi

    2017-01-11

    In nodal-line semimetals, the gaps close along loops in k space, which are not at high-symmetry points. Typical mechanisms for the emergence of nodal lines involve mirror symmetry and the π Berry phase. Here we show via ab initio calculations that fcc calcium (Ca), strontium (Sr) and ytterbium (Yb) have topological nodal lines with the π Berry phase near the Fermi level, when spin-orbit interaction is neglected. In particular, Ca becomes a nodal-line semimetal at high pressure. Owing to nodal lines, the Zak phase becomes either π or 0, depending on the wavevector k, and the π Zak phase leads to surface polarization charge. Carriers eventually screen it, leaving behind large surface dipoles. In materials with nodal lines, both the large surface polarization charge and the emergent drumhead surface states enhance Rashba splitting when heavy adatoms are present, as we have shown to occur in Bi/Sr(111) and in Bi/Ag(111).

  8. Direct Measurement of Topological Phases in Discrete-Time Quantum Walks: Theory

    NASA Astrophysics Data System (ADS)

    Ramasesh, Vinay; Flurin, Emmanuel; Siddiqi, Irfan; Yao, Norman

    Quantum walks have been intently investigated theoretically, from initial studies motivated by their connection to classical randomized algorithms to more recent works demonstrating topological phenomena in these walks. In particular, quantum walks simulate dynamics under effective lattice Hamiltonians which feature spin-orbit coupling. Here, we demonstrate that by adding an additional coin operator which varies from step to step, one can perform a traversal of the effective Brillouin zone, analogous to a Bloch oscillation. The geometric phase picked up by the walker along the Bloch oscillation is a genuine signature of the walk's topology, a quantity known in 1D as the Zak phase. Unlike previous interferometric proposals, our work requires neither spin-dependent Ramsey spectroscopy nor an external impurity with additional degrees of freedom. We develop a protocol, illustrating its use in a circuit QED system, which allows for the detection of the Zak phase. This research is supported by the ARO.

  9. NRC/AMRMC Resident Research Associateship Program

    DTIC Science & Technology

    2015-03-01

    International Domestic Spencer W. Stonier, Andrew S. Herbert , Ariel Sobarzo, Ana I. Kuehne, Yael Eskira, Julius Lutwama, Leslie Lobel, and John M. Dye...Christopher Patrick Minogue, Timothy Devins 1/2/2014-1/1/2016 Stojadinovic, Marija Panchal, Rekha G. 12/1/2014-11/30/2015 Stonier, Spencer William Dye...page number(s), and year of publication. a) Publications in peer-reviewed journals Herbert AS, Kuehne AI, Barth JF, Ortiz RA, Nichols DK, Zak SE

  10. Analysis and Forecasting of Operating and Support Costs for F-16 C/D

    DTIC Science & Technology

    2006-06-01

    Plastycznej Świdnik Sp. z o.o. Textron (Lycoming) Zakład Obróbki Plastycznej Świdnik Sp. z o.o., Świdnik 28 2-116 Start-up production at Opel ...Polska Sp. z o.o. of a new model car T-3000 Astra and the production of spare parts. Lockheed Martin Aeronautics Co. Opel Polska Sp. z o.o

  11. Novel Topological Phase with a Zero Berry Curvature

    NASA Astrophysics Data System (ADS)

    Liu, Feng; Wakabayashi, Katsunori

    2017-02-01

    We present a two-dimensional (2D) lattice model that exhibits a nontrivial topological phase in the absence of the Berry curvature. Instead, the Berry connection provides the topological nontrivial phase in the model, whose integration over the momentum space, the so-called 2D Zak phase, yields a fractional wave polarization in each direction. These fractional wave polarizations manifest themselves as degenerated edge states with opposite parities in the model.

  12. Hypersensitive radical probe studies of chloroperoxidase-catalyzed hydroxylation reactions.

    PubMed

    Toy, P H; Newcomb, M; Hager, L P

    1998-07-01

    The oxidation of hypersensitive radical probes by chloroperoxidase from Caldariomyces fumago (CPO) was studied in an attempt to "time" a putative radical intermediate. Oxidation of (trans-2-phenylcyclopropyl)methane, previously studied by Zaks and Dodds [Zaks, A., and Dodds, D. R. (1995) J. Am. Chem. Soc. 115, 10419-10424] was reinvestigated. Unrearranged oxidation products were found as previously reported, and control experiments demonstrated that the cyclic alcohol from oxidation at the cyclopropylcarbinyl position, while subject to further oxidation, survives CPO oxidation as detectable species. However, in contrast to the report by Zaks and Dodds, the rearranged alcohol product expected from ring opening of a cyclopropylcarbinyl radical intermediate was shown to be unstable toward the enzyme oxidation reaction. Because of this instability, two new hypersensitive radical probes, (trans-2-phenylcyclopropyl)ethane and 2-(trans-2-phenylcyclopropyl)propane, and their potential cyclic and acyclic products from oxidation at the cyclopropylcarbinyl position were synthesized and tested. Oxidation of both of these probes at the cyclopropylcarbinyl position by CPO gave unrearranged alcohol products only, but control experiments again demonstrated that the rearranged alcohol products were unstable toward CPO oxidation conditions. From the combination of the probe and control studies, the lifetime of a putative radical intermediate must be less than 3 ps. Whereas the results are consistent with an insertion mechanism for production of alcohol product, they do not exclude a very short-lived intermediate.

  13. Generating scientific models of knowledge using arcs.

    PubMed

    Kim, Jinshil; Pressler, Susan J; Jones, Josette; Graves, Judith R

    2008-01-01

    Systematic approaches are needed to review literature on nutrition in heart failure for its scientific merit, relevance, and usefulness and identify directions for future research. To evaluate the feasibility of arcs (J.R.G., Indianapolis, Indiana), a computer program for managing data from literature and modeling knowledge, the objectives were to conduct an integrative review of 10 studies of nutrition in heart failure and generate scientific models of knowledge using arcs. A unit of knowledge in arcs is 2 variables linked by a statistical relationship. The computer program arcs categorized variables and relationships found in the 10 explanatory observational studies. It also provided a scientific model for further empirical testing. The computer program arcs aggregated the following: 104 dependent and 93 independent operational variables and 60 associational, 16 predictive, 15 structural, 1 descriptive, and 85 difference relationships. A direct model produced by arcs postulated a structural relationship between cachexia and 18-month mortality, independent of age or New York Heart Association classification, which can be tested as a path theoretical model. The computer program arcs appeared to be feasible for conducting an integrative review of nutrition in heart failure. A larger, representative set of literature will enable generation of knowledge and identification of gaps and inconsistencies in findings.

  14. Strongly lensed gravitational waves from intrinsically faint double compact binaries—prediction for the Einstein Telescope

    SciTech Connect

    Ding, Xuheng; Biesiada, Marek; Zhu, Zong-Hong E-mail: marek.biesiada@us.edu.pl

    2015-12-01

    With a fantastic sensitivity improving significantly over the advanced GW detectors, Einstein Telescope (ET) will be able to observe hundreds of thousand inspiralling double compact objects per year. By virtue of gravitational lensing effect, intrinsically unobservable faint sources can be observed by ET due to the magnification by intervening galaxies. We explore the possibility of observing such faint sources amplified by strong gravitational lensing. Following our previous work, we use the merger rates of DCO (NS-NS,BH-NS,BH-BH systems) as calculated by Dominik et al.(2013). It turns out that tens to hundreds of such (lensed) extra events will be registered by ET. This will strongly broaden the ET's distance reach for signals from such coalescences to the redshift range z = 2 − 8. However, with respect to the full inspiral event catalog this magnification bias is at the level of 0.001 and should not affect much cosmological inferences.

  15. Lagrangian Modeling of the Atmosphere

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2013-08-01

    Like watching a balloon borne by the breeze, a Lagrangian model tracks a parcel of air as it flows through the atmosphere. Whether running forward or backward in time, Lagrangian models offer a powerful tool for tracking and understanding the fates, or origins, of atmospheric flows. In the AGU monograph Lagrangian Modeling of the Atmosphere, editors John Lin, Dominik Brunner, Christoph Gerbig, Andreas Stohl, Ashok Luhar, and Peter Webley explore the nuances of the modeling technique. In this interview Eos talks to Lin about the growing importance of Lagrangian modeling as the world settles on climate change mitigation strategies, the societal value of operational modeling, and how recent advances are making it possible to run these complex calculations at home.

  16. Offshore Wind Farms in the North Sea: Is there an effect on the zooplankton community?

    NASA Astrophysics Data System (ADS)

    Auch, Dominik; Dudeck, Tim; Callies, Ulrich; Riethmüller, Rolf; Hufnagl, Marc; Eckhardt, André; Ove Möller, Klas; Haas, Bianca; Spreitzenbarth, Stefan; van Beusekom, Justus; Walter, Bettina; Temming, Axel; Möllmann, Christian; Floeter, Jens

    2016-04-01

    The climate conference in Paris 2015 has resulted in ambitious goals to mitigate the extent of global climate warming within this century. In Germany, the expansion of renewable energy sources is without any alternative to match the own aims of greenhouse gas reductions. Therefore, in the German EEZ of the North Sea around 10 offshore wind farms (OWFs) are already working and more are currently planned or already under construction. At this already substantial level of offshore wind energy production little is known about the effects of OWFs on the pelagic ecosystem. Earlier investigations have shown an increase of benthic organisms settling on hard substrates provided by the power plant foundations. However, the effects of offshore power plants on lower trophic level organisms within the water column are poorly understood. Thus, we investigated the abundance and distribution of zooplankton within and around OWFs. The analysis was based on optical data derived from a Video Plankton Recorder (VPR). The VPR was mounted on a TRIAXUS system including a suite of different sensors, hence allowing to combine zooplankton information with ambient hydrographic parameters. The combination of the VPR and the TRIAXUS system enabled us to analyse continuous zooplankton and hydrographic data with a high spatial resolution. In this study, we present results of transects through the OWFs Global Tech I, BARD Offshore 1, and Alpha Ventus. The analysis exhibits distinct pattern in the spatial distribution both of physical state variables and of plankton organisms within the vicinity of OWFs, especially of meroplankton, the larval phase of benthic organisms. Keywords: Offshore Wind Farms, Zooplankton, TRIAXUS, Video Plankton Recorder, Meroplankton Corresponding author: Dominik Auch, Institute for Hydrobiology and Fisheries Science, University of Hamburg, Olbersweg 24, 22767 Hamburg, Germany; auch.dominik@web.de

  17. Electrophysiological Correlates of Vernier Acuity in Human Visual Cortex.

    DTIC Science & Technology

    1984-04-28

    RD-A146 533 ELECTROPHYSIOLOGICAL CORRELATES OF VERNIER ACUITY IN 1/2 HUMAN VISUAL CORTEX(U) ARMY MILITARY PERSONNEL CENTER ALEXANDRIA YA R ZRK 28 APR...CORRELATES OF VERNIER 28 APRIL 84 ACUITY IN HUMAN VISUAL CORTEX - 9. PERFORMING ORG. REPORT NUMBER T . AUTHO~’a) S. CONTRACT OR GRANT NUMBER(&) Zak, Richard...number) *Vernier acuity- Vision- Perception- Visual Evoked Potentials 06A ACT (001mm on powawO slab If aeeeW MA fdmtltF by *look number) C A three part

  18. Multiple Microcomputer Control Algorithm.

    DTIC Science & Technology

    1979-09-01

    Processor for the SMS Multimicro- processor System", Second SYOposium on Micro-Architecture, North Holland Publ. Co., 1976, pp. I83-189. 28...Processor for the SMS Multimicroproces- sor System," *Srodn iV o MjcoLH-AvhIteturg (Sami. M., Wilmink. J., and Zaks, R., Ed’s.), North- Holland Publ. Co...TE HP lOP TCIII1. * RuN: -T RIIE Trmp~inp. Triwo1. H 1 I:FAI !’,F SCH: -TRIIE I ENDI 194 NAVTRAEQUIPCEN 78-C-0157-1 END ELSE TEMPJ0:mTEMPrlfP.NFXT

  19. Synergistic Interactions with PI3K Inhibition that Induce Apoptosis. | Office of Cancer Genomics

    Cancer.gov

    Activating mutations involving the PI3K pathway occur frequently in human cancers. However, PI3K inhibitors primarily induce cell cycle arrest, leaving a significant reservoir of tumor cells that may acquire or exhibit resistance. We searched for genes that are required for the survival of PI3K mutant cancer cells in the presence of PI3K inhibition by conducting a genome scale shRNA-based apoptosis screen in a PIK3CA mutant human breast cancer cell. We identified 5 genes (PIM2, ZAK, TACC1, ZFR, ZNF565) whose suppression induced cell death upon PI3K inhibition.

  20. Inference Based on Simple Step Statistics for the Location Model.

    DTIC Science & Technology

    1981-07-01

    function. Let TN,k(9) - Zak(’)Vi(e). Then TNk is called the k-step statistic. Noether (1973) studied the 1-step statistic with particular emphasis on...opposed to the sign statistic. These latter two comparisons were first discussed by Noether (1973) in a somewhat different setting. Notice that the...obtained by Noether (1973). If k - 3, we seek the (C + 1)’st and (2N - bI - b2 - C)’th ordered Walsh averages in D The algorithm of Section 3 modified to

  1. Topological Dirac nodal lines and surface charges in fcc alkaline earth metals

    PubMed Central

    Hirayama, Motoaki; Okugawa, Ryo; Miyake, Takashi; Murakami, Shuichi

    2017-01-01

    In nodal-line semimetals, the gaps close along loops in k space, which are not at high-symmetry points. Typical mechanisms for the emergence of nodal lines involve mirror symmetry and the π Berry phase. Here we show via ab initio calculations that fcc calcium (Ca), strontium (Sr) and ytterbium (Yb) have topological nodal lines with the π Berry phase near the Fermi level, when spin–orbit interaction is neglected. In particular, Ca becomes a nodal-line semimetal at high pressure. Owing to nodal lines, the Zak phase becomes either π or 0, depending on the wavevector k, and the π Zak phase leads to surface polarization charge. Carriers eventually screen it, leaving behind large surface dipoles. In materials with nodal lines, both the large surface polarization charge and the emergent drumhead surface states enhance Rashba splitting when heavy adatoms are present, as we have shown to occur in Bi/Sr(111) and in Bi/Ag(111). PMID:28074835

  2. Direct Measurement of Topological Phases in Discrete-Time Quantum Walks - Experiment

    NASA Astrophysics Data System (ADS)

    Flurin, Emmanuel; Ramasesh, Vinay V.; Hacohen Gourgy, Shay; Yao, Norman Y.; Siddiqi, Irfan

    We perform quantum walks in a cavity QED architecture. Here a transmon qubit plays the role of the quantum coin, while a set of coherent states in an electromagnetic cavity forms the walker's lattice. The strong dispersive coupling between the transmon and cavity naturally implements coin-dependent translations of the walker state. The walk is performed by applying qubit rotations at equally spaced intervals; interestingly, such systems simulate dynamics under effective lattice Hamiltonians which feature strong spin-orbit coupling, leading to non-trivial band topology. By adding an additional step-dependent coin operator, we perform the first direct measurement of a quantum walk Zak phase, delineating between topologically trivial and non-trivial walks. The geometric phase is detected by implementing the quantum walk with the initial state of the walker in a superposition of a coherent state and the vacuum state, which does not partake in the walk. The Zak phase acquired by the walker thus leaves an imprint in the interference fringes of the resulting Schrodinger cat state. We observe these fringes by directly measuring the cavity Wigner function. This research is supported by the ARO.

  3. BRAF inhibitors suppress apoptosis through off-target inhibition of JNK signaling

    PubMed Central

    Vin, Harina; Ojeda, Sandra S; Ching, Grace; Leung, Marco L; Chitsazzadeh, Vida; Dwyer, David W; Adelmann, Charles H; Restrepo, Monica; Richards, Kristen N; Stewart, Larissa R; Du, Lili; Ferguson, Scarlett B; Chakravarti, Deepavali; Ehrenreiter, Karin; Baccarini, Manuela; Ruggieri, Rosamaria; Curry, Jonathan L; Kim, Kevin B; Ciurea, Ana M; Duvic, Madeleine; Prieto, Victor G; Ullrich, Stephen E; Dalby, Kevin N; Flores, Elsa R; Tsai, Kenneth Y

    2013-01-01

    Vemurafenib and dabrafenib selectively inhibit the v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) kinase, resulting in high response rates and increased survival in melanoma. Approximately 22% of individuals treated with vemurafenib develop cutaneous squamous cell carcinoma (cSCC) during therapy. The prevailing explanation for this is drug-induced paradoxical ERK activation, resulting in hyperproliferation. Here we show an unexpected and novel effect of vemurafenib/PLX4720 in suppressing apoptosis through the inhibition of multiple off-target kinases upstream of c-Jun N-terminal kinase (JNK), principally ZAK. JNK signaling is suppressed in multiple contexts, including in cSCC of vemurafenib-treated patients, as well as in mice. Expression of a mutant ZAK that cannot be inhibited reverses the suppression of JNK activation and apoptosis. Our results implicate suppression of JNK-dependent apoptosis as a significant, independent mechanism that cooperates with paradoxical ERK activation to induce cSCC, suggesting broad implications for understanding toxicities associated with BRAF inhibitors and for their use in combination therapies. DOI: http://dx.doi.org/10.7554/eLife.00969.001 PMID:24192036

  4. Superradiant Topological Peierls Insulator inside an Optical Cavity

    NASA Astrophysics Data System (ADS)

    Mivehvar, Farokh; Ritsch, Helmut; Piazza, Francesco

    2017-02-01

    We consider a spinless ultracold Fermi gas tightly trapped along the axis of an optical resonator and transversely illuminated by a laser closely tuned to a resonator mode. At a certain threshold pump intensity, the homogeneous gas density breaks a Z2 symmetry towards a spatially periodic order, which collectively scatters pump photons into the cavity. We show that this known self-ordering transition also occurs for low field seeking fermionic particles when the laser light is blue detuned to an atomic transition. The emergent superradiant optical lattice in this case is homopolar and possesses two distinct dimerizations. Depending on the spontaneously chosen dimerization, the resulting Bloch bands can have a nontrivial topological structure characterized by a nonvanishing Zak phase. In the case where the Fermi momentum is close to half of the cavity-mode wave number, a Peierls-like instability here creates a topological insulator with a gap at the Fermi surface, which hosts a pair of edge states. The topological features of the system can be nondestructively observed via the cavity output: the Zak phase of the bulk coincides with the relative phase between laser and cavity field, while the fingerprint of edge states can be observed as additional broadening in a well-defined frequency window of the cavity spectrum.

  5. Superradiant Topological Peierls Insulator inside an Optical Cavity.

    PubMed

    Mivehvar, Farokh; Ritsch, Helmut; Piazza, Francesco

    2017-02-17

    We consider a spinless ultracold Fermi gas tightly trapped along the axis of an optical resonator and transversely illuminated by a laser closely tuned to a resonator mode. At a certain threshold pump intensity, the homogeneous gas density breaks a Z_{2} symmetry towards a spatially periodic order, which collectively scatters pump photons into the cavity. We show that this known self-ordering transition also occurs for low field seeking fermionic particles when the laser light is blue detuned to an atomic transition. The emergent superradiant optical lattice in this case is homopolar and possesses two distinct dimerizations. Depending on the spontaneously chosen dimerization, the resulting Bloch bands can have a nontrivial topological structure characterized by a nonvanishing Zak phase. In the case where the Fermi momentum is close to half of the cavity-mode wave number, a Peierls-like instability here creates a topological insulator with a gap at the Fermi surface, which hosts a pair of edge states. The topological features of the system can be nondestructively observed via the cavity output: the Zak phase of the bulk coincides with the relative phase between laser and cavity field, while the fingerprint of edge states can be observed as additional broadening in a well-defined frequency window of the cavity spectrum.

  6. Reservoir-induced Thouless pumping and symmetry-protected topological order in open quantum chains

    NASA Astrophysics Data System (ADS)

    Linzner, D.; Wawer, L.; Grusdt, F.; Fleischhauer, M.

    2016-11-01

    We introduce a classification of symmetry-protected topological phases applicable to stationary states of open systems based on a generalization of the many-body polarization. The polarization can be used to probe topological properties of noninteracting and interacting closed and open systems and remains a meaningful quantity even in the presence of moderate particle-number fluctuations. As examples, we discuss two open-system versions of a topological Thouless pump in the steady state of one-dimensional lattices driven by Markovian reservoirs. In an analogous unitary system, the Su-Shrieffer-Heeger model, symmetries enforce a quantization of the geometric Zak phase, which acts as a topological invariant. Introducing a further degree of freedom, a nontrivial winding of the phase can be observed upon cyclic variations of parameters. Associated with this is a quantization or, respectively, a winding of the polarization corresponding to a quantized transport (Thouless pump). We here show that in the open system, where the Zak phase loses its meaning, the same symmetries enforce a quantization and more generally a winding of the generalized many-body polarization. These features are shown to be robust against Hamiltonian perturbations as well as homogeneous dephasing and particle losses.

  7. Measuring Z2 topological invariants in optical lattices using interferometry

    NASA Astrophysics Data System (ADS)

    Grusdt, F.; Abanin, D.; Demler, E.

    2014-04-01

    We propose an interferometric method to measure Z2 topological invariants of time-reversal invariant topological insulators realized with optical lattices in two and three dimensions. We suggest two schemes which both rely on a combination of Bloch oscillations with Ramsey interferometry and can be implemented using standard tools of atomic physics. In contrast to topological Zak phase and Chern number, defined for individual one-dimensional and two-dimensional Bloch bands, the formulation of the Z2 invariant involves at least two Bloch bands related by time-reversal symmetry which one must keep track of in measurements. In one of our schemes this can be achieved by the measurement of Wilson loops, which are non-Abelian generalizations of Zak phases. The winding of their eigenvalues is related to the Z2 invariant. We thereby demonstrate that Wilson loops are not just theoretical concepts but can be measured experimentally. For the second scheme we introduce a generalization of time-reversal polarization which is continuous throughout the Brillouin zone. We show that its winding over half the Brillouin zone yields the Z2 invariant. To measure this winding, our protocol only requires Bloch oscillations within a single band, supplemented by coherent transitions to a second band which can be realized by lattice shaking.

  8. Distribution of 7Be, 210Pb and 137Cs in watersheds of different scales in the Seine River basin: inventories and residence times.

    PubMed

    Le Cloarec, Marie-Françoise; Bonté, Philippe; Lefèvre, Irène; Mouchel, Jean-Marie; Colbert, Steven

    2007-04-01

    The activity of environmental radionuclides ((7)Be, (210)Pb and (137)Cs) was monitored in nested catchments, inside the Seine River basin. Suspended matter data was collected at 8 different watersheds, ranging from order 1 to order 7, and ranging in size over 4 orders of magnitude. Suspended matter was analyzed for (210)Pb, (137)Cs and (7)Be, and used to calculate the flux of sediments out of each watershed. Monthly atmospheric flux data of (210)Pb and (7)Be was analyzed to assess the input flux of each into the watersheds, taking into account the rainfall during sampling periods. Taking advantage of the different half-lives of (7)Be (53 days) and (210)Pb (22 years), a two-box model was built for each of the catchments following a methodology previously developed by Dominik et al. [Dominik J, Burrus D, Vernet JP. Transport of the environmental radionuclides in alpine watershed. Earth Planet Sci Letters 1987; 84: 165-180.]. The model divides the watershed into a soil box and a rapid reservoir and provides insight into the removal rate of suspended matter from the surrounding watershed. The model enables the assessment of the surface area and the residence time of slow and rapid reservoirs to describe the fate of contaminants of atmospheric origin inside the river basin. The model was improved by considering the dissolved fraction in the total flux and adding the (137)Cs inventory as an additional constraint. The effects of these changes are discussed. Residence times in the soil box, characterized by low transport velocity, range between 4800 years at Melarchez (order 1) to about 30000 years at Andresy and Poses (order 7). They remain constant in each watershed over a large range of variation of atmospheric fluxes of (7)Be and (210)Pb during the whole study, but are sensitive to SM variations. The residence time in the rapid box, which includes the surface of the river and immediate surroundings, is less than one year, while its surface area is in the range 0.6% to

  9. Contributions of other sterols to the estimation of cholesterol.

    PubMed

    Munster, D J; Lever, M; Carrell, R W

    1976-04-15

    The responses of 5alpha-cholestan-3beta-ol, 5alpha-cholest-7-ene-3beta-ol and cholesta-5,7-dien-3beta-ol, normally found in human serum, were examined by: (1) the Liebermann-Burchard reaction, (2) the Zak (ferric chloride) reaction, (3) an enzymatic cholesterol method monitored by estimating the amount of hydrogen peroxide produced, (4) an enzymatic cholesterol method monitored by observing the change in absorbance at 240 nm, and (5) gas chromatography. The results show that none of these methods is specific for cholesterol; contributions from the sterols examined range from zero to more than 150% relative to cholesterol. For the first four methods contributions depend on the conditions under which each test is performed.

  10. Interacting scale invariant but nonconformal field theories

    NASA Astrophysics Data System (ADS)

    Nakayama, Yu

    2017-03-01

    There is a dilemma in constructing interacting scale invariant Euclidean field theories that are not conformal invariant. On one hand, scale invariance without conformal invariance seems more generic by requiring only a smaller symmetry. On the other hand, the existence of a nonconserved current with exact scaling dimension d -1 in d dimensions seems to require extra fine-tuning. To understand the competition better, we explore some examples without the reflection positivity. We show that a theory of elasticity (also known as Riva-Cardy theory) coupled with massless fermions in d =4 -ɛ dimensions does not possess an interacting scale invariant fixed point except for an unstable (and unphysical) one with an infinite coefficient of compression. We do, however, find interacting scale invariant but nonconformal field theories in gauge fixed versions of the Banks-Zaks fixed points in d =4 dimensions.

  11. Topological phase transition and interface states in hybrid plasmonic-photonic systems

    NASA Astrophysics Data System (ADS)

    Ge, Lixin; Liu, Liang; Xiao, Meng; Du, Guiqiang; Shi, Lei; Han, Dezhuan; Chan, C. T.; Zi, Jian

    2017-06-01

    The geometric phase and topological property for one-dimensional hybrid plasmonic-photonic crystals consisting of a simple lattice of graphene sheets are investigated systematically. For transverse magnetic waves, both plasmonic and photonic modes exist in the momentum space. The accidental degeneracy point of these two kinds of modes is identified to be a diabolic point accompanied with a topological phase transition. For a closed loop around this degeneracy point, the Berry phase is π as a consequence of the discontinuous jump of the geometric Zak phase. The wave impedance is calculated analytically for the semi-infinite system, and the corresponding topological interface states either start from or terminate at the degeneracy point. This type of localized interface state may find potential applications in manipulation of photon emission of quantum dots, optical sensing and enhancement of nonlinear effects, etc.

  12. Topological origin of edge states in two-dimensional inversion-symmetric insulators and semimetals

    NASA Astrophysics Data System (ADS)

    van Miert, Guido; Ortix, Carmine; Morais Smith, Cristiane

    2017-03-01

    Symmetries play an essential role in identifying and characterizing topological states of matter. Here, we classify topologically two-dimensional (2D) insulators and semimetals with vanishing spin-orbit coupling using time-reversal ({ T }) and inversion ({ I }) symmetry. This allows us to link the presence of edge states in { I } and { T } symmetric 2D insulators, which are topologically trivial according to the Altland-Zirnbauer table, to a {{{Z}}}2 topological invariant. This invariant is directly related to the quantization of the Zak phase. It also predicts the generic presence of edge states in Dirac semimetals, in the absence of chiral symmetry. We then apply our findings to bilayer black phosphorus and show the occurrence of a gate-induced topological phase transition, where the {{{Z}}}2 invariant changes.

  13. Optimum Multisensor, Multitarget Localization and Tracking.

    DTIC Science & Technology

    1983-06-07

    target j and sensor i, respectively. The log-likelihood function of Equation (3.2-la) is defined by B A(D) L log p(2 !D) k=l B : -MB log( Ir ) -ZAk(D) k=1...3.3-2) and (3.3-5) in (3.4-2), we immediately obtain ii A B [r R1 3RkRI aRk1:- tr Rkl 9R k k k=1L IR -1 a Rk + R (3.4-3) * ~tr~k aeas aeiaei Rk) 2o...CD LL 0 C - CL tA (a 𔃾- 0w 0 0: 0 C. LU; LL- 78 Ir cc, 0 S0 - 0 0. 0 0~9 0f 08- om L.0 -CD 4 I 43 4U 0 4 -J I S o 4o S- o 1 1 - 1 l r -I oo I- OIIVU

  14. Topological Fulde-Ferrell states in alkaline-earth-metal-like atoms near an orbital Feshbach resonance

    NASA Astrophysics Data System (ADS)

    Wang, Su; Pan, Jian-Song; Cui, Xiaoling; Zhang, Wei; Yi, Wei

    2017-04-01

    We study the effects of synthetic spin-orbit coupling on the pairing physics in quasi-one-dimensional ultracold Fermi gases of alkaline-earth-metal-like atoms near an orbital Feshbach resonance (OFR). The interplay between spin-orbit coupling and pairing interactions near the OFR leads to an interesting topological Fulde-Ferrell state, where the nontrivial topology of the state is solely encoded in the closed channel with a topologically trivial Fulde-Ferrell pairing in the open channel. We confirm the topological property of the system by characterizing the Zak phase and the edge states. The topological Fulde-Ferrell state can be identified by the momentum-space density distribution obtained from time-of-flight images.

  15. Statistical mechanics approach to the electric polarization and dielectric constant of band insulators

    NASA Astrophysics Data System (ADS)

    Combes, Frédéric; Trescher, Maximilian; Piéchon, Frédéric; Fuchs, Jean-Noël

    2016-10-01

    We develop a theory for the analytic computation of the free energy of band insulators in the presence of a uniform and constant electric field. The two key ingredients are a perturbation-like expression of the Wannier-Stark energy spectrum of electrons and a modified statistical mechanics approach involving a local chemical potential in order to deal with the unbounded spectrum and impose the physically relevant electronic filling. At first order in the field, we recover the result of King-Smith, Vanderbilt, and Resta for the electric polarization in terms of a Zak phase—albeit at finite temperature—and, at second order, deduce a general formula for the electric susceptibility, or equivalently for the dielectric constant. Advantages of our method are the validity of the formalism both at zero and finite temperature and the easy computation of higher order derivatives of the free energy. We verify our findings on two different one-dimensional tight-binding models.

  16. Unparticle example in 2D.

    PubMed

    Georgi, Howard; Kats, Yevgeny

    2008-09-26

    We discuss what can be learned about unparticle physics by studying simple quantum field theories in one space and one time dimension. We argue that the exactly soluble 2D theory of a massless fermion coupled to a massive vector boson, the Sommerfield model, is an interesting analog of a Banks-Zaks model, approaching a free theory at high energies and a scale-invariant theory with nontrivial anomalous dimensions at low energies. We construct a toy standard model coupling to the fermions in the Sommerfield model and study how the transition from unparticle behavior at low energies to free particle behavior at high energies manifests itself in interactions with the toy standard model particles.

  17. Education with Infrared Astronomy and Spitzer

    NASA Astrophysics Data System (ADS)

    Hemphill, Rosa; Blackwell, J. A.; Herrold, A.; Petroff, E.

    2007-12-01

    We present education and outreach results using our experiences involving the Spitzer Space Telescope project, Star Formation in High Redshift Clusters with Spitzer. The project is a collaboration between the Spitzer Science Center and the National Optical Astronomy Observatory. Using the Spitzer Space Telescope, we measured star formation rates in three galaxy clusters at intermediate redshifts. Six teachers were chosen for the program, each with an interest and involvement in astronomy education. From this project, lesson plans, public outreach, lectures and demonstrations were generated which better the understanding of infrared astronomy, multiwavelength astronomy, galaxy and star formation, and cosmology. The teacher mentors are Dr. Gregory Rudnick (NOAO), Dr. Rose Finn (Siena College), and Dr. Vandana Desai (Caltech). Please see the companion posters by Emily Petroff, Zak Schroeder, and Thomas Loughran, et al, for information concerning the science results.

  18. Fractional lattice charge transport

    PubMed Central

    Flach, Sergej; Khomeriki, Ramaz

    2017-01-01

    We consider the dynamics of noninteracting quantum particles on a square lattice in the presence of a magnetic flux α and a dc electric field E oriented along the lattice diagonal. In general, the adiabatic dynamics will be characterized by Bloch oscillations in the electrical field direction and dispersive ballistic transport in the perpendicular direction. For rational values of α and a corresponding discrete set of values of E(α) vanishing gaps in the spectrum induce a fractionalization of the charge in the perpendicular direction - while left movers are still performing dispersive ballistic transport, the complementary fraction of right movers is propagating in a dispersionless relativistic manner in the opposite direction. Generalizations and the possible probing of the effect with atomic Bose-Einstein condensates and photonic networks are discussed. Zak phase of respective band associated with gap closing regime has been computed and it is found converging to π/2 value. PMID:28102302

  19. Fuzzy model-based observers for fault detection in CSTR.

    PubMed

    Ballesteros-Moncada, Hazael; Herrera-López, Enrique J; Anzurez-Marín, Juan

    2015-11-01

    Under the vast variety of fuzzy model-based observers reported in the literature, what would be the properone to be used for fault detection in a class of chemical reactor? In this study four fuzzy model-based observers for sensor fault detection of a Continuous Stirred Tank Reactor were designed and compared. The designs include (i) a Luenberger fuzzy observer, (ii) a Luenberger fuzzy observer with sliding modes, (iii) a Walcott-Zak fuzzy observer, and (iv) an Utkin fuzzy observer. A negative, an oscillating fault signal, and a bounded random noise signal with a maximum value of ±0.4 were used to evaluate and compare the performance of the fuzzy observers. The Utkin fuzzy observer showed the best performance under the tested conditions. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  20. Direct manifestation of topological order in the winding number of the Wannier-Stark ladder

    NASA Astrophysics Data System (ADS)

    Lee, Woo-Ram; Park, Kwon

    2015-11-01

    Topological quantum phases of matter have been a topic of intense interest in contemporary condensed matter physics. Extensive efforts are devoted to investigate various exotic properties of topological matter including topological insulators, topological superconductors, and topological semimetals. For topological insulators, the dissipationless transport via gapless helical edge or surface states is supposed to play a defining role, which unfortunately has proved difficult to realize in experiments due to inevitable backscattering induced in the sample boundary. Motivated by the fundamental connection between topological invariants and the Zak phase, here, we show that the nontrivial band topologies of both two- and three-dimensional topological insulators, characterized by the Chern numbers and the Z2 invariants, respectively, are directly manifested in the winding numbers of the Wannier-Stark ladder (WSL) emerging under an electric field. We use the Floquet Green's function formalism to show that the winding number of the WSL is robust against interband interference as well as nonmagnetic impurity scattering.

  1. Interferometric Approach to Measuring Band Topology in 2D Optical Lattices

    NASA Astrophysics Data System (ADS)

    Abanin, Dmitry A.; Kitagawa, Takuya; Bloch, Immanuel; Demler, Eugene

    2013-04-01

    Recently, optical lattices with nonzero Berry’s phases of Bloch bands have been realized. New approaches for measuring Berry’s phases and topological properties of bands with experimental tools appropriate for ultracold atoms need to be developed. In this Letter, we propose an interferometric method for measuring Berry’s phases of two-dimensional Bloch bands. The key idea is to use a combination of Ramsey interference and Bloch oscillations to measure Zak phases, i.e., Berry’s phases for closed trajectories corresponding to reciprocal lattice vectors. We demonstrate that this technique can be used to measure the Berry curvature of Bloch bands, the π Berry’s phase of Dirac points, and the first Chern number of topological bands. We discuss several experimentally feasible realizations of this technique, which make it robust against low-frequency magnetic noise.

  2. Balian-Low phenomenon for subspace Gabor frames

    NASA Astrophysics Data System (ADS)

    Gabardo, Jean-Pierre; Han, Deguang

    2004-08-01

    In this work, the Balian-Low theorem is extended to Gabor (also called Weyl-Heisenberg) frames for subspaces and, more particularly, its relationship with the unique Gabor dual property for subspace Gabor frames is pointed out. To achieve this goal, the subspace Gabor frames which have a unique Gabor dual of type I (resp. type II) are defined and characterized in terms of the Zak transform for the rational parameter case. This characterization is then used to prove the Balian-Low theorem for subspace Gabor frames. Along the same line, the same characterization is used to prove a duality theorem for the unique Gabor dual property which is an analogue of the Ron and Shen duality theorem.

  3. Quantum charge pumps with topological phases in a Creutz ladder

    NASA Astrophysics Data System (ADS)

    Sun, Ning; Lim, Lih-King

    2017-07-01

    The quantum charge pumping phenomenon connects band topology through the dynamics of a one-dimensional quantum system. In terms of a microscopic model, the Su-Schrieffer-Heeger/Rice-Mele quantum pump continues to serve as a fruitful starting point for many considerations of topological physics. Here we present a generalized Creutz scheme as a distinct two-band quantum pump model. By noting that it undergoes two kinds of topological band transitions accompanying with a Zak-phase difference of π and 2 π , respectively, various charge pumping schemes are studied by applying an elaborate Peierls phase substitution. Translating into real space, the transportation of quantized charges is a result of cooperative quantum interference effect. In particular, an all-flux quantum pump emerges which operates with time-varying fluxes only and transports two charge units. This makes cold atoms with artificial gauge fields a unique system where this kind of phenomena can be realized.

  4. Fuzzy Model of Autogenous Suspension Coal Cleaning / Model Rozmyty Procesu Wzbogacania Węgla W Zawiesinie Autogenicznej

    NASA Astrophysics Data System (ADS)

    Benović, Tomo; Miljanović, Igor; Vujić, Slobodan

    2012-12-01

    The paper presents one of the possible approaches to fuzzy logic modeling of coal cleaning in autogenous suspension. In the scope of reviewing the problem in general, the process algorithm and the structural model of coal cleaning were set up. The paper deals with the flow of fuzzy logic model creation following the example of coal cleaning plant of the "Bogutovo selo" open pit mine of the Mine and Thermal Power Plant Ugljevik. The model is set up on the MATLAB software platform. Fuzzy model testing results, presented at the end of paper confirms applicability and reliability of the model. The discrepancies between the model and the real process parameters are within the limits of allowed industrial error. W pracy przedstawiono jedną z dostępnych metod modelowania rozmytego zastosowaną do modelowania procesu wzbogacania węgla w zawiesinie autogenicznej. Analiza problemu obejmuje przedstawienie algorytmu procesu wzbogacania oraz jego model strukturalny. W pracy przedstawiono proces tworzenia modelu rozmytego na przykładzie zakładu wzbogacania `Bogutovo selo' przy kopalni odkrywkowej będącej częścią zakładów górniczych i elektrowni Ugljevik. Model stworzono przy wykorzystaniu platformy MATLAB. Wyniki testowania modelu rozmytego zaprezentowane w artykule potwierdzają przydatność i wiarygodność modelu. Rozbieżności pomiędzy wynikami modelowania a parametrami rzeczywistych procesów mieszczą się w dopuszczalnych przy procesach przemysłowych granicach tolerancji błędu.

  5. a Rigorous Comparison of Theoretical and Measured Carbon Dioxide Line Intensities

    NASA Astrophysics Data System (ADS)

    Yi, Hongming; Fleisher, Adam J.; Gameson, Lyn; Zak, Emil J.; Polyansky, Oleg; Tennyson, Jonathan; Hodges, Joseph T.

    2017-06-01

    The ability to calculate molecular line intensities from first principles plays an increasingly important role in populating line-by-line spectroscopic databases because of its generality and extensibility to various isotopologues, spectral ranges and temperature conditions. Such calculations require a spectroscopically determined potential energy surface, and an accurate dipole moment surface that can be either fully ab initio or an effective quantity based on fits to measurements Following our recent work where we used high-precision measurements of intensities in the (30013 →00001) band of ^{12}C^{16}O_2 to bound the uncertainty of calculated line lists, here we carry out high-precision, frequency-stabilized cavity ring-down spectroscopy measurements in the R-branch of the ^{12}C^{16}O_2 (20012 →00001) band from J = 16 to 52. Gas samples consisted of 50 μmol mol^{-1} or 100 μmol mol^{-1} of nitrogen-broadened carbon dioxide with gravimetrically determined SI-traceable molar composition. We demonstrate relative measurement precision (Type A) at the 0.15 % level and estimate systematic (Type B) uncertainty contributions in % of: isotopic abundance 0.01; sample density, 0.016; cavity free spectral rang,e 0.03; line shape, 0.05; line interferences, 0.05; and carbon dioxide molar fraction, 0.06. Combined in quadrature, these components yield a relative standard uncertainty in measured line intensity less than 0.2 % for most observed transitions. These intensities differ by more than 2 % from those measured by Fourier transform spectroscopy and archived in HITRAN 2012 but differ by less than 0.5 % with the calculations of Zak et al. E. Zak et al., J. Quant. Spectrosc. Radiat. Transf. 177, (2016) 31. Huang et al., J. Quant. Spectrosc. Radiat. Transf. 130, (2013) 134. Tashkun et al., J. Quant. Spectrosc. Radiat. Transf. 152, (2015) 45.

  6. The Formation Of The First Solids In The Solar System: An Investigation Of CAI Diversity

    NASA Astrophysics Data System (ADS)

    Taillifet, Esther; Baillié, K.; Charnoz, S.; Aléon, J.

    2012-10-01

    Chondritic meteorites are primitive bodies and therefore an important source of information on the first moments of planets formation. Chondrites contain several materials especially calcium and aluminum rich inclusions (CAIs), known to be the oldest objects of the solar system (4.567 Gyr - Amelin et al., 2002; Connelly et al., 2008) and thus the first solids to be formed. CAIs appear in various textures, sizes and compositions in chondrites. Though, all of them should have formed at high temperature (1300-1800 K) in the same region of the solar nebula by condensation from the gas (e.g. Grossman, 1972; Yoneda & Grossman, 1995; Petaev & Wood, 1998; Ebel & Grossman 2000). To answer this problem we study the CAI formation within the solar nebula using numerical simulations. For this work we developed a self consistent thermodynamical model of the solar nebula (see associated talk from Baillié et. al ) based on previous works (Calvet et. al, 1991; Hueso & Guillot, 2005; Dullemond, Dominik and Natta, 2001). Using this model, we simulate the young system with Lagrangian Implicit Disk Transport code (LIDT - Charnoz et. al, 2010). We will focus on the very first instants of the CAIs within the few years following their condensation. We will report our first results in terms of thermal history and investigate if turbulence-driven transport may explain the CAI diversity.

  7. Herbig stars' near-infrared excess: An origin in the protostellar disk's magnetically supported atmosphere

    SciTech Connect

    Turner, N. J.; Benisty, M.; Dullemond, C. P.; Hirose, S.

    2014-01-01

    Young stars with masses 2-8 times solar, the Herbig Ae and Be stars, often show a near-infrared excess too large to explain with a hydrostatically supported circumstellar disk of gas and dust. At the same time, the accretion flow carrying the circumstellar gas to the star is thought to be driven by magnetorotational turbulence, which, according to numerical MHD modeling, yields an extended low-density atmosphere supported by the magnetic fields. We demonstrate that the base of the atmosphere can be optically thick to the starlight and that the parts lying near 1 AU are tall enough to double the fraction of the stellar luminosity reprocessed into the near-infrared. We generate synthetic spectral energy distributions (SEDs) using Monte Carlo radiative transfer calculations with opacities for submicron silicate and carbonaceous grains. The synthetic SEDs closely follow the median Herbig SED constructed recently by Mulders and Dominik and, in particular, match the large near-infrared flux, provided the grains have a mass fraction close to interstellar near the disk's inner rim.

  8. THE PHYSICS OF PROTOPLANETESIMAL DUST AGGLOMERATES. VI. EROSION OF LARGE AGGREGATES AS A SOURCE OF MICROMETER-SIZED PARTICLES

    SciTech Connect

    Schraepler, Rainer; Blum, Juergen

    2011-06-20

    Observed protoplanetary disks consist of a large amount of micrometer-sized particles. Dullemond and Dominik pointed out for the first time the difficulty in explaining the strong mid-infrared excess of classical T Tauri stars without any dust-retention mechanisms. Because high relative velocities in between micrometer-sized and macroscopic particles exist in protoplanetary disks, we present experimental results on the erosion of macroscopic agglomerates consisting of micrometer-sized spherical particles via the impact of micrometer-sized particles. We find that after an initial phase, in which an impacting particle erodes up to 10 particles of an agglomerate, the impacting particles compress the agglomerate's surface, which partly passivates the agglomerates against erosion. Due to this effect, the erosion halts for impact velocities up to {approx}30 m s{sup -1} within our error bars. For higher velocities, the erosion is reduced by an order of magnitude. This outcome is explained and confirmed by a numerical model. In a next step, we build an analytical disk model and implement the experimentally found erosive effect. The model shows that erosion is a strong source of micrometer-sized particles in a protoplanetary disk. Finally, we use the stationary solution of this model to explain the amount of micrometer-sized particles in the observational infrared data of Furlan et al.

  9. Few Skewed Disks Found in First Closure-Phase Survey of Herbig Ae/Be Stars

    NASA Astrophysics Data System (ADS)

    Monnier, J. D.; Berger, J.-P.; Millan-Gabet, R.; Traub, W. A.; Schloerb, F. P.; Pedretti, E.; Benisty, M.; Carleton, N. P.; Haguenauer, P.; Kern, P.; Labeye, P.; Lacasse, M. G.; Malbet, F.; Perraut, K.; Pearlman, M.; Zhao, M.

    2006-08-01

    Using the three-telescope IOTA interferometer on Mount Hopkins, we report results from the first near-infrared (λ=1.65 μm) closure-phase survey of young stellar objects (YSOs). These closure phases allow us to unambiguously detect departures from centrosymmetry (i.e., skew) in the emission pattern from YSO disks on the scale of ~4 mas, expected from generic ``flared disk'' models. Six of 14 targets showed small, yet statistically significant nonzero closure phases, with largest values from the young binary system MWC 361-A and the (pre-main-sequence?) Be star HD 45677. Our observations are quite sensitive to the vertical structure of the inner disk, and we confront the predictions of the ``puffed-up inner wall'' models of Dullemond, Dominik, & Natta (DDN). Our data support disk models with curved inner rims because the expected emission appears symmetrically distributed around the star over a wide range of inclination angles. In contrast, our results are incompatible with the models possessing vertical inner walls because they predict extreme skewness (i.e., large closure phases) from the near-IR disk emission that is not seen in our data. In addition, we also present the discovery of mysterious H-band ``halos'' (~5%-10% of light on scales 0.01"-0.50") around a few objects, a preliminary ``parametric imaging'' study for HD 45677, and the first astrometric orbit for the young binary MWC 361-A.

  10. Characteristics of dune-paleosol-sequences in Fuerteventura. - What should be questioned?

    NASA Astrophysics Data System (ADS)

    Faust, Dominik; Willkommen, Tobias; Yanes, Yurena; Richter, David; Zöller, Ludwig

    2013-04-01

    Characteristics of dune-paleosol-sequences in Fuerteventura. - What should be questioned? Dominik Faust, TU Dresden, Germany Tobias Willkommen, TU Dresden, Germany Yurena Yanes, CSIC Granada/Cincinatti, Spain/USA David Richter, TU Dresden, Germany Ludwig Zöller, Uni Bayreuth, Germany The northern part of Fuerteventura is characterized by large dune fields. We investigated dune-paleosol-sequences in four pits to establish a robust stratigraphy and to propose a standard section. An interaction of processes like dune formation, soil formation and redeposition of soils and sand are most important to understand the principles of landscape development in the study area. To our mind a process cycle seem to be important: First climbing-dunes are formed by sand of shelf origin. Then soil formation could have taken place. Soil and/or sand were then eroded and deposited at toe slope position. This material in turn is the source of new sand supply and dune formation. The described cycle may be repeated several times and this ping-pong-process holds on. The results are sections composed of dune layers, paleosols and colluvial material interbedded. Fundamental questions still remain unanswered: Is climate change responsable for changes in process combination (e.g. from dune formation to soil formation)? Or are these features due to divergence phenomenon, where different effects/results (dune and soils) may be linked to similar causes (here: climate)? Assuming that different features (soils and dunes) were formed under one climate, increasing soil forming intensity could be mainly a function of decreasing sand supply. This in turn could be caused by reduced sand production (s. ZECH et al. accepted). However geochemical data and mollusc assemblages point to changing environments in space and even climate modifications in time.

  11. Effect of High Altitude Exposure on Intraocular Pressure Using Goldmann Applanation Tonometry.

    PubMed

    Willmann, Gabriel; Schommer, Kai; Schultheiss, Maximilian; Fischer, M Dominik; Bartz-Schmidt, Karl-Ulrich; Gekeler, Florian; Schatz, Andreas

    2017-06-01

    Willmann, Gabriel, Kai Schommer, Maximilian Schultheiss, M. Dominik Fischer, Karl-Ulrich Bartz-Schmidt, Florian Gekeler, and Andreas Schatz. Effect of high altitude exposure on intraocular pressure using Goldmann applanation tonometry. High Alt Med Biol. 18:114-120, 2017. The aim of the study was to quantify changes of intraocular pressure (IOP) during exposure to 4559 m using the state-of-the-art method of Goldmann applanation tonometry for IOP measurement and to detect correlations between IOP and acute mountain sickness (AMS) in a prospective manner. IOP was measured using a Goldmann applanation tonometer AT 900(®) (Haag-Streit, Switzerland) and central corneal thickness (CCT) with the anterior segment module of a Spectralis™ HRA+OCT(®) device (Heidelberg Engineering, Germany) at baseline and high altitude. Assessment of AMS was performed using the Lake Louise and AMS-C questionnaires, and Pearson's correlation coefficient was calculated for association between IOP and AMS. Raw IOP values at high altitude were not significantly changed compared to baseline. IOP adjusted to the increase in CCT at high altitude, which is known to alter IOP levels, showed a significant reduction for corrected IOP values on day 3 of exposure (morning -2.1 ± 1.2 mmHg; evening -2.3 ± 1.1 mmHg; p < 0.05). No correlation of IOP with AMS or clinical parameters (heart rate and SpO2) at high altitude was noted. IOP showed a significant reduction of IOP levels when corrected for increased CCT values at high altitude. Furthermore, the prospective measurement of IOP is not useful in diagnosing AMS or for the prediction of more severe high altitude related illnesses as the decrease in IOP and symptoms of AMS do not correlate during altitude exposure.

  12. Single-mode interface states in heterostructure waveguides with Bragg and non-Bragg gaps

    PubMed Central

    Fan, Ya-Xian; Sang, Tang-Qing; Liu, Ting; Xu, Lan-Lan; Tao, Zhi-Yong

    2017-01-01

    Interface states can always arise in heterostructures that consist of two or more (artificial) materials with topologically different energy bands. The gapped band structure can be classified by the Chern number (a topological invariant) generally or the Zak phase in one-dimensional periodic systems. Recently, topological properties have been employed to investigate the interface states occurring at the connecting regions of the heterostructures of mechanical isostatic lattices and acoustical waveguides. Here, we study this heterostructure phenomenon by carefully connecting two corrugated stainless steel waveguides with Bragg and non-Bragg gaps at approximately the same frequency. These two waveguide structures can be achieved by continuously varying their geometry parameters when a topological transition exists in the forbidden bands, in which the reflection impedance changes the sign. Furthermore, a localized single high-order mode has been observed at the interface because of the transverse mode interactions, which relate to the non-Bragg gaps created by the different transverse mode resonances. Such a localized acoustic single mode with very large enhanced intensity could find its applications in sound detection, biomedical imaging, and underwater sound control, and could also enrich our means of wave front manipulations in various engineering fields. PMID:28287173

  13. The Treatment of Restless Legs Syndrome and Periodic Limb Movement Disorder in Adults—An Update for 2012: Practice Parameters with an Evidence-Based Systematic Review and Meta-Analyses

    PubMed Central

    Aurora, R. Nisha; Kristo, David A.; Bista, Sabin R.; Rowley, James A.; Zak, Rochelle S.; Casey, Kenneth R.; Lamm, Carin I.; Tracy, Sharon L.; Rosenberg, Richard S.

    2012-01-01

    A systematic literature review and meta-analyses (where appropriate) were performed to update the previous AASM practice parameters on the treatments, both dopaminergic and other, of RLS and PLMD. A considerable amount of literature has been published since these previous reviews were performed, necessitating an update of the corresponding practice parameters. Therapies with a STANDARD level of recommendation include pramipexole and ropinirole. Therapies with a GUIDELINE level of recommendation include levodopa with dopa decarboxylase inhibitor, opioids, gabapentin enacarbil, and cabergoline (which has additional caveats for use). Therapies with an OPTION level of recommendation include carbamazepine, gabapentin, pregabalin, clonidine, and for patients with low ferritin levels, iron supplementation. The committee recommends a STANDARD AGAINST the use of pergolide because of the risks of heart valve damage. Therapies for RLS secondary to ESRD, neuropathy, and superficial venous insufficiency are discussed. Lastly, therapies for PLMD are reviewed. However, it should be mentioned that because PLMD therapy typically mimics RLS therapy, the primary focus of this review is therapy for idiopathic RLS. Citation: Aurora RN; Kristo DA; Bista SR; Rowley JA: Zak RS; Casey KR; Lamm CI; Tracy SL; Rosenberg RS. The treatment of restless legs syndrome and periodic limb movement disorder in adults—an update for 2012: practice parameters with an evidence-based systematic review and meta-analyses. SLEEP 2012;35(8):1039-1062. PMID:22851801

  14. Transcriptomic analysis of gene expression profiles of stomach carcinoma reveal abnormal expression of mitotic components.

    PubMed

    Tong, Hongfei; Wang, Jisheng; Chen, Hui; Wang, Zhaohong; Fan, Henwei; Ni, Zhonglin

    2017-02-01

    In order to explore the etiology of gastric cancer on global gene expression level, we developed advanced bioinformatic analysis to investigate the variations of global gene expression and the interactions among them. We downloaded the dataset GSE63288 from Gene Expression Omnibus (GEO) database which included 22 human gastric cancer and 22 healthy control samples. We identified the differential expression genes, and explored the Gene ontology (GO) and pathways of the differentially expressed genes. Furthermore, integrative interaction network and co-expression network were employed to identify the key genes which may contribute to gastric cancer progression. The results indicated that 5 kinases including BUB1, TTK protein kinase, Citron Rho-interacting kinase (CIT), ZAK and NEK2 were upregulated in gastric cancer. Interestingly, BUB1, TTK, CIT and NEK2 have shown high expression similarities and bound with each other, and participated in multiple phases of mitosis. Moreover, a subnet of co-expression genes e.g. KIF14, PRC1, CENPF and CENPI was also involved in mitosis which was functionally coupled with the kinases above. By validation assays, the results indicated that CIT, PRC1, TTK and KIF14 were significantly upregulated in gastric cancer. These evidences have suggested that aberrant expression of these genes may drive gastric cancer including progression, invasion and metastasis. Although the causal relationships between gastric cancer and the genes are still lacking, it was reasonable to take them as biomarkers for diagnosis of gastric cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. The existence of topological edge states in honeycomb plasmonic lattices

    NASA Astrophysics Data System (ADS)

    Wang, Li; Zhang, Ruo-Yang; Xiao, Meng; Han, Dezhuan; Chan, C. T.; Wen, Weijia

    2016-10-01

    In this paper, we investigate the band properties of 2D honeycomb plasmonic lattices consisting of metallic nanoparticles. By means of the coupled dipole method and quasi-static approximation, we theoretically analyze the band structures stemming from near-field interaction of localized surface plasmon polaritons for both the infinite lattice and ribbons. Naturally, the interaction of point dipoles decouples into independent out-of-plane and in-plane polarizations. For the out-of-plane modes, both the bulk spectrum and the range of the momentum k ∥ where edge states exist in ribbons are similar to the electronic bands in graphene. Nevertheless, the in-plane polarized modes show significant differences, which do not only possess additional non-flat edge states in ribbons, but also have different distributions of the flat edge states in reciprocal space. For in-plane polarized modes, we derived the bulk-edge correspondence, namely, the relation between the number of flat edge states at a fixed {k}\\parallel , Zak phases of the bulk bands and the winding number associated with the bulk Hamiltonian, and verified it through four typical ribbon boundaries, i.e. zigzag, bearded zigzag, armchair, and bearded armchair. Our approach gives a new topological understanding of edge states in such plasmonic systems, and may also apply to other 2D ‘vector wave’ systems.

  16. Topological interface states between a photonic crystal and a metasurface (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Wang, Qiang; Xiao, Meng; Liu, Hui; Zhu, Shining; Chan, Cheting

    2016-09-01

    Topological invariant plays a more and more important role in modern physics with the discovery of new materials such as topological insulators. The concept of momentum space topology has also been extended to various photonic systems to realize interesting applications. In this work, a plasmonic interface state is introduced between a photonic crystal and a metasurface which is protected by the Z2 topological mirror symmetry of the photonic crystals. Here we propose a scheme to experimentally measure the topological phase in a photonic system. Using reflection spectrum measurement, we determined the existence of interface states in the gaps, and then obtained the Zak phases. The interface state is excited when the reflection phase matching condition is satisfied. The reflection phase of metasurface can be tuned by changing the structural parameter. The resonance properties of interface state can be manipulated in the process. By manipulating the anisotropic property of the metasurface, we can further tune the polarization of the interface state. Field enhancement induced by the interface state will have important applications in nonlinear and quantum optics.

  17. Single-mode interface states in heterostructure waveguides with Bragg and non-Bragg gaps

    NASA Astrophysics Data System (ADS)

    Fan, Ya-Xian; Sang, Tang-Qing; Liu, Ting; Xu, Lan-Lan; Tao, Zhi-Yong

    2017-03-01

    Interface states can always arise in heterostructures that consist of two or more (artificial) materials with topologically different energy bands. The gapped band structure can be classified by the Chern number (a topological invariant) generally or the Zak phase in one-dimensional periodic systems. Recently, topological properties have been employed to investigate the interface states occurring at the connecting regions of the heterostructures of mechanical isostatic lattices and acoustical waveguides. Here, we study this heterostructure phenomenon by carefully connecting two corrugated stainless steel waveguides with Bragg and non-Bragg gaps at approximately the same frequency. These two waveguide structures can be achieved by continuously varying their geometry parameters when a topological transition exists in the forbidden bands, in which the reflection impedance changes the sign. Furthermore, a localized single high-order mode has been observed at the interface because of the transverse mode interactions, which relate to the non-Bragg gaps created by the different transverse mode resonances. Such a localized acoustic single mode with very large enhanced intensity could find its applications in sound detection, biomedical imaging, and underwater sound control, and could also enrich our means of wave front manipulations in various engineering fields.

  18. Topological water wave states in a one-dimensional structure

    PubMed Central

    Yang, Zhaoju; Gao, Fei; Zhang, Baile

    2016-01-01

    Topological concepts have been introduced into electronic, photonic, and phononic systems, but have not been studied in surface-water-wave systems. Here we study a one-dimensional periodic resonant surface-water-wave system and demonstrate its topological transition. By selecting three different water depths, we can construct different types of water waves - shallow, intermediate and deep water waves. The periodic surface-water-wave system consists of an array of cylindrical water tanks connected with narrow water channels. As the width of connecting channel varies, the band diagram undergoes a topological transition which can be further characterized by Zak phase. This topological transition holds true for shallow, intermediate and deep water waves. However, the interface state at the boundary separating two topologically distinct arrays of water tanks can exhibit different bands for shallow, intermediate and deep water waves. Our work studies for the first time topological properties of water wave systems, and paves the way to potential management of water waves. PMID:27373982

  19. [A comparative analysis of occupational risk in industry employees based on concentrations of some elements in teeth and body fluids].

    PubMed

    Poczatek, Michał; Machoy, Zygmunt; Gutowska, Izabela; Chlubek, Dariusz

    2004-01-01

    Work safety and hygiene is a set of basic measures to protect workers from the negative effects of manufacturing processes. So far, numerous procedures for assessment of occupational health risk have been described. We measured the concentrations of some elements in teeth and body fluids of employees working in three different industries with an established production profile: Zakłady Naprawcze Taboru Kolejowego (repairs of rail vehicles), Philips Lighting Poland (production of lighting systems) and Metalplast (build ing furbishing factory). Different technologies were in place at each of these plants. Basing on laboratory analyses, the risk of exposure to chemical substances was evaluated. The study material included 100 extracted teeth, as well as body fluid samples (saliva, urine and blood) collected during routine health checks. Whenever possible, concentrations of the following elements were measured: calcium, magnesium, fluorine, phosphorus in the form of phosphates, potassium, sodium, iron, zinc, copper, cadmium, and lead. Metal elements were measured spectrophotometrically (ASA), fluorine with an ion-selective electrode, and phosphates with a colorimetric method. We found that concentrations of the elements in teeth and body fluids differed depending on the industry. For teeth, statistically significant differences applied to magnesium, phosphates, zinc, sodium, and potassium. In body fluids, statistically significant differences were found for calcium (blood and urine), magnesium (blood, urine and saliva), zinc (blood, urine and saliva), iron, lead and copper (urine). In conclusion, our findings may be helpful for monitoring safety at work in industrial plants.

  20. Consistent Perturbative Fixed Point Calculations in QCD and Supersymmetric QCD.

    PubMed

    Ryttov, Thomas A

    2016-08-12

    We suggest how to consistently calculate the anomalous dimension γ_{*} of the ψ[over ¯]ψ operator in finite order perturbation theory at an infrared fixed point for asymptotically free theories. If the n+1 loop beta function and n loop anomalous dimension are known, then γ_{*} can be calculated exactly and fully scheme independently in a Banks-Zaks expansion through O(Δ_{f}^{n}), where Δ_{f}=N[over ¯]_{f}-N_{f}, N_{f} is the number of flavors, and N[over ¯]_{f} is the number of flavors above which asymptotic freedom is lost. For a supersymmetric theory, the calculation preserves supersymmetry order by order in Δ_{f}. We then compute γ_{*} through O(Δ_{f}^{2}) for supersymmetric QCD in the dimensional reduction scheme and find that it matches the exact known result. We find that γ_{*} is astonishingly well described in perturbation theory already at the few loops level throughout the entire conformal window. We finally compute γ_{*} through O(Δ_{f}^{3}) for QCD and a variety of other nonsupersymmetric fermionic gauge theories. Small values of γ_{*} are observed for a large range of flavors.

  1. Continuum regularization of quantum field theory

    SciTech Connect

    Bern, Z.

    1986-04-01

    Possible nonperturbative continuum regularization schemes for quantum field theory are discussed which are based upon the Langevin equation of Parisi and Wu. Breit, Gupta and Zaks made the first proposal for new gauge invariant nonperturbative regularization. The scheme is based on smearing in the ''fifth-time'' of the Langevin equation. An analysis of their stochastic regularization scheme for the case of scalar electrodynamics with the standard covariant gauge fixing is given. Their scheme is shown to preserve the masslessness of the photon and the tensor structure of the photon vacuum polarization at the one-loop level. Although stochastic regularization is viable in one-loop electrodynamics, two difficulties arise which, in general, ruins the scheme. One problem is that the superficial quadratic divergences force a bottomless action for the noise. Another difficulty is that stochastic regularization by fifth-time smearing is incompatible with Zwanziger's gauge fixing, which is the only known nonperturbaive covariant gauge fixing for nonabelian gauge theories. Finally, a successful covariant derivative scheme is discussed which avoids the difficulties encountered with the earlier stochastic regularization by fifth-time smearing. For QCD the regularized formulation is manifestly Lorentz invariant, gauge invariant, ghost free and finite to all orders. A vanishing gluon mass is explicitly verified at one loop. The method is designed to respect relevant symmetries, and is expected to provide suitable regularization for any theory of interest. Hopefully, the scheme will lend itself to nonperturbative analysis. 44 refs., 16 figs.

  2. Topological collective plasmons in bipartite chains of metallic nanoparticles

    NASA Astrophysics Data System (ADS)

    Downing, Charles A.; Weick, Guillaume

    2017-03-01

    We study a bipartite linear chain constituted by spherical metallic nanoparticles, where each nanoparticle supports a localized surface plasmon. The near-field dipolar interaction between the localized surface plasmons gives rise to collective plasmons, which are extended over the whole nanoparticle array. We derive analytically the spectrum and the eigenstates of the collective plasmonic excitations. At the edge of the Brillouin zone, the spectrum is of a pseudorelativistic nature similar to that present in the electronic band structure of polyacetylene. We find the effective Dirac Hamiltonian for the collective plasmons and show that the corresponding spinor eigenstates represent one-dimensional Dirac-like massive bosonic excitations. Therefore, the plasmonic lattice exhibits similar effects to those found for electrons in one-dimensional Dirac materials, such as the ability for transmission with highly suppressed backscattering due to Klein tunneling. We also show that the system is governed by a nontrivial Zak phase, which predicts the manifestation of edge states in the chain. When two dimerized chains with different topological phases are connected, we find the appearance of the bosonic version of a Jackiw-Rebbi midgap state. We further investigate the radiative and nonradiative lifetimes of the collective plasmonic excitations and comment on the challenges for experimental realization of the topological effects found theoretically.

  3. Consistent Perturbative Fixed Point Calculations in QCD and Supersymmetric QCD

    NASA Astrophysics Data System (ADS)

    Ryttov, Thomas A.

    2016-08-01

    We suggest how to consistently calculate the anomalous dimension γ* of the ψ ¯ ψ operator in finite order perturbation theory at an infrared fixed point for asymptotically free theories. If the n +1 loop beta function and n loop anomalous dimension are known, then γ* can be calculated exactly and fully scheme independently in a Banks-Zaks expansion through O (Δfn) , where Δf=N¯ f-Nf , Nf is the number of flavors, and N¯f is the number of flavors above which asymptotic freedom is lost. For a supersymmetric theory, the calculation preserves supersymmetry order by order in Δf. We then compute γ* through O (Δf2) for supersymmetric QCD in the dimensional reduction scheme and find that it matches the exact known result. We find that γ* is astonishingly well described in perturbation theory already at the few loops level throughout the entire conformal window. We finally compute γ* through O (Δf3) for QCD and a variety of other nonsupersymmetric fermionic gauge theories. Small values of γ* are observed for a large range of flavors.

  4. Long-range doublon transfer in a dimer chain induced by topology and ac fields

    PubMed Central

    Bello, M.; Creffield, C. E.; Platero, G.

    2016-01-01

    The controlled transfer of particles from one site of a spatial lattice to another is essential for many tasks in quantum information processing and quantum communication. In this work we study how to induce long-range transfer between the two ends of a dimer chain, by coupling states that are localized just on the chain’s end-points. This has the appealing feature that the transfer occurs only between the end-points – the particle does not pass through the intermediate sites–making the transfer less susceptible to decoherence. We first show how a repulsively bound-pair of fermions, known as a doublon, can be transferred from one end of the chain to the other via topological edge states. We then show how non-topological surface states of the familiar Shockley or Tamm type can be used to produce a similar form of transfer under the action of a periodic driving potential. Finally we show that combining these effects can produce transfer by means of more exotic topological effects, in which the driving field can be used to switch the topological character of the edge states, as measured by the Zak phase. Our results demonstrate how to induce long range transfer of strongly correlated particles by tuning both topology and driving. PMID:26932406

  5. Topological water wave states in a one-dimensional structure

    NASA Astrophysics Data System (ADS)

    Yang, Zhaoju; Gao, Fei; Zhang, Baile

    2016-07-01

    Topological concepts have been introduced into electronic, photonic, and phononic systems, but have not been studied in surface-water-wave systems. Here we study a one-dimensional periodic resonant surface-water-wave system and demonstrate its topological transition. By selecting three different water depths, we can construct different types of water waves - shallow, intermediate and deep water waves. The periodic surface-water-wave system consists of an array of cylindrical water tanks connected with narrow water channels. As the width of connecting channel varies, the band diagram undergoes a topological transition which can be further characterized by Zak phase. This topological transition holds true for shallow, intermediate and deep water waves. However, the interface state at the boundary separating two topologically distinct arrays of water tanks can exhibit different bands for shallow, intermediate and deep water waves. Our work studies for the first time topological properties of water wave systems, and paves the way to potential management of water waves.

  6. Quality Measures for the Care of Adult Patients with Restless Legs Syndrome

    PubMed Central

    Trotti, Lynn Marie; Goldstein, Cathy A.; Harrod, Christopher G.; Koo, Brian B.; Sharon, Denise; Zak, Rochelle; Chervin, Ronald D.

    2015-01-01

    The American Academy of Sleep Medicine (AASM) commissioned several Workgroups to develop quality measures for the care of patients with common sleep disorders, including adults with restless legs syndrome (RLS). Using the AASM process for quality measure development, the RLS Work-group developed three target outcomes for RLS management, including improving the accuracy of diagnosis, reducing symptom severity, and minimizing treatment complications. Seven processes were developed to support these outcomes. To achieve the outcome of improving accuracy of diagnosis, the use of accepted diagnostic criteria and assessment of iron stores are recommended. To realize the outcome of decreasing symptom severity, routine assessment of severity and provision of evidence-based treatment are recommended. To support the outcome of minimizing treatment complications, counseling about potential side effects and assessing for augmentation and impulse control disorders, when indicated, are recommended. Further research is needed to validate optimal practice processes to achieve best outcomes in adult patients with RLS. Citation: Trotti LM, Goldstein CA, Harrod CG, Koo BB, Sharon D, Zak R, Chervin RD. Quality measures for the care of adult patients with restless legs syndrome. J Clin Sleep Med 2015;11(3):293–310. PMID:25700882

  7. Exploring arbitrarily high orders of optimized perturbation theory in QCD with nf → 161/2

    NASA Astrophysics Data System (ADS)

    Stevenson, P. M.

    2016-09-01

    Perturbative QCD with nf flavours of massless quarks becomes simple in the hypothetical limit nf → 161/2, where the leading β-function coefficient vanishes. The Banks-Zaks (BZ) expansion in a0 ≡8/321 (161/2 -nf) is straightforward to obtain from perturbative results in MS ‾ or any renormalization scheme (RS) whose nf dependence is 'regular'. However, 'irregular' RS's are perfectly permissible and should ultimately lead to the same BZ results. We show here that the 'optimal' RS determined by the Principle of Minimal Sensitivity does yield the same BZ-expansion results when all orders of perturbation theory are taken into account. The BZ limit provides an arena for exploring optimized perturbation theory at arbitrarily high orders. These explorations are facilitated by a 'master equation' expressing the optimization conditions in the fixed-point limit. We find an intriguing strong/weak coupling duality a →a*2 / a about the fixed point a*.

  8. [Iodine content of cattle milk from mountain and coast from Perú].

    PubMed

    Cárdenas Quintana, Haydeé; Gómez Bravo, Carlos; Pretell, Eduardo A

    2003-12-01

    With the objective to establish the cause-effect relationship between a geological area and the iodine content in cattle milk, and to estimate the contribution of milk consumption to the dietary iodine intake, the iodine content in cattle milk from the sierra and the coastal regions of Perú was determined. Milk samples were collected of cows from the three main productive zones of Perú, 62 in Cajamarca, 42 in Arequipa, both in the sierra, and 27 in Lima at the coast. The measurement of iodine was made by the method of Zak, based on the Sandell- Kolthoff reaction. The median values obtained were 24 microg/L in Cajamarca, 34 microg/L in Arequipa, and 170 microg/L in Lima. The median value in the sierra, 26 microg/L, was significantly lower than the one found in the coast. Moreover, while in the former 81% of individual values were below 50 microg/L, in the latter, on the contrary, 77% were above 80 microg/L. These results confirm that the iodine content in cattle milk is related to ecological factors. At the same time, they demonstrate that the iodine content in milk from the sierra is six times lower than in milk from the coast, and also that its consumption does not contribute significantly to satisfy the human physiological requirements of iodine in that zone.

  9. Small deformation of a simple N =2 superconformal theory

    NASA Astrophysics Data System (ADS)

    Buican, Matthew; Nishinaka, Takahiro

    2016-12-01

    We study an interesting relevant deformation of the simplest interacting N =2 superconformal field theory (SCFT)—the original Argyres-Douglas (AD) theory. We argue that, although this deformation is not strictly speaking Banks-Zaks-like (certain operator dimensions change macroscopically), there are senses in which it constitutes a mild deformation of the parent AD theory: the exact change in the a anomaly is small and is essentially saturated at one loop. Moreover, contributions from IR operators that have a simple description in the UV theory reproduce a particular limit of the IR index to a remarkably high order. These results lead us to conclude that the IR theory is an interacting N =1 SCFT with particularly small a and c central charges and that this theory sheds some interesting light on the spectrum of its AD parent. Our results also lead us to the conclusion that the theory spaces emanating from some of the simplest N =1 gauge theories may be richer than anticipated.

  10. Reconstruction of the polarization distribution of the Rice-Mele model

    NASA Astrophysics Data System (ADS)

    Yahyavi, M.; Hetényi, B.

    2017-06-01

    We calculate the gauge-invariant cumulants (and moments) associated with the Zak phase in the Rice-Mele model. We reconstruct the underlying probability distribution by maximizing the information entropy and applying the moments as constraints. When the Wannier functions are localized within one unit cell, the probability distribution so obtained corresponds to that of the Wannier function. We show that in the fully dimerized limit the magnitudes of the moments are all equal. In this limit, if the on-site interaction is decreased towards zero, the distribution shifts towards the midpoint of the unit cell, but the overall shape of the distribution remains the same. Away from this limit, if alternate hoppings are finite and the on-site interaction is decreased, the distribution also shifts towards the midpoint of the unit cell, but it does this by changing shape, by becoming asymmetric around the maximum, and by shifting. We also follow the probability distribution of the polarization in cycles around the topologically nontrivial point of the model. The distribution moves across to the next unit cell, its shape distorting considerably in the process. If the radius of the cycle is large, the shift of the distribution is accompanied by large variations in the maximum.

  11. Geomorphological indicators of coseismic and extreme-rainfall slope instabilities in alpine settings (New Zealand, China, Taiwan)

    NASA Astrophysics Data System (ADS)

    Raab, Theresa; Leith, Kerry; Krautblatter, Michael

    2016-04-01

    Wenchuan and progressive slope failure in Taiwan in the years following the events. Interestingly, we find that coseismically induced landslides follow normal trends with respect to slope gradient, whereas slope failures during typhoon Morakot preferentially occurred on steeper slopes than during weak typhoons. In the regions of the 2003 and 2007 earthquakes in Fiordland, as well as in the region of the Wenchuan earthquake, landslide orientation does not suggest enhanced susceptibility due to topographic amplification of oblique incoming seismic waves, and may instead reflect the dependence of weathering and soil production on slope aspect. Slope aspect preference is highly variable in Taiwan, and dependent on wind directions during typhoons. While we cannot account for correlations between sensitivity and landslide occurrence during heavy rainfall events, we identify a noticeable increase in landslide occurrence with increasing sensitivity during seismic shaking. Additionally, landslide rates were found to remain elevated for 1 year, 2 years and 5 years, after typhoon Morakot, the 2003 Fiordland earthquake and the 2008 Wenchuan earthquake, respectively. However, further research needs to be carried out on this newly developed technique of identifying and analyzing slope failures using a global treeloss catalogue. Hansen, M.C., Potapov, P.V., Moore, R., Hancher, M., Turubanova, S.A., Tyukavina, A., Thau, D., Stehman, S. V., Goetz, S.J., Loveland, T.R., Kommareddy, A., Egorov, A., Chini, L., Justice, C.O. & Townshend, J.R.G. (2013): High-Resolution Global Maps of 21st-Century Forest Cover Change. - Science, 342: 850-853.

  12. A Complex Organic Slushy Bathing Low-Mass Protostars

    NASA Astrophysics Data System (ADS)

    Drozdovskaya, Maria; Walsh, Catherine; Visser, Ruud; Harsono, Daniel; van Dishoeck, Ewine

    2015-08-01

    Complex organic molecules are ubiquitous companions of young forming stars. They were first observed in hot cores surrounding high-mass protostars [e.g., 1], but have since also been detected in the environs of several low-mass counterparts [e.g., 2]. Recent studies have shown that colder envelopes and positions with impinging outflows may also glow with emission from complex organic species [e.g., 3, 4]. For this meeting, I would like to present physicochemical modeling results on the synthesis of complex organics in an envelope-cavity system that is subject to non-thermal processing. This includes wavelength-dependent radiative transfer calculations with RADMC [5] and a comprehensive gas-grain chemical network [6]. The results show that the morphology of such a system delineates three distinct regions: the cavity wall layer with time-dependent and species-variant enhancements; a torus rich in complex organic ices, but not reflected in gas-phase abundances; and the remaining outer envelope abundant in simpler solid and gaseous molecules. Within the adopted paradigm, complex organic molecules are demonstrated to have unique lifetimes and be grouped into early and late species [7]. Key chemical processes for forming and destroying complex organic molecules will be discussed. In addition, the results of adding newly experimentally verified routes [8] into the existing chemical networks will be shown.[1] Blake G. A., Sutton E. C., Masson C. R., Phillips T. G., 1987, ApJ, 315, 621[2] Jørgensen J. K., Favre C., Bisschop S. E., Bourke T. L., van Dishoeck E. F., Schmalzl M., 2012, ApJ, 757, L4[3] Arce H. G., Santiago-García J., Jørgensen J. K., Tafalla M., Bachiller R., 2008, ApJ, 681, L21[4] Öberg K. I., Bottinelli S., Jørgensen J. K., van Dishoeck E. F., 2010, ApJ, 716, 825[5] Dullemond C. P., Dominik C., 2004, A&A, 417, 159[6] Walsh C., Millar T. J., Nomura H., Herbst E., Widicus Weaver S., Aikawa Y., Laas J. C., Vasyunin A. I., 2014, A&A, 563, A33[7] Drozdovskaya

  13. PEGASUS - An Austrian Nanosatellite for QB50

    NASA Astrophysics Data System (ADS)

    Scharlemann, Carsten; Seifert, Bernhard; Kohl, Dominik; Birschitzky, David; Gury, Lionel; Kerschbaum, Franz; Obertscheider, Christof; Ottensamer, Roland; Reissner, Alexander; Riel, Thomas; Sypniewski, Richard; Taraba, Michael; Trausmuth, Robert; Turetschek, Thomas

    2015-04-01

    PEGASUS - An Austrian Nanosatellite for QB50 C. Scharlemann* David Birschitzky* Lionel Gury*, Franz Kerschbaum~, Dominik Kohl#, Christof Obertscheider*, Roland Ottensamer~, Alexander Reissner+, Thomas Riel#, B. Seifert+, Richard Sypniewski*, Michael Taraba?, Robert Trausmuth*, Thomas Turetschek?, …. (*)University of Applied Sciences Wiener Neustadt, Austria (+)FOTEC GmbH, Wiener Neustadt, Austria (+) Spaceteam, TU Wien, Austria (~) University Wien, Wien, Austria The QB50 project is an international project with the goal to send up to 50 Nanosatellites, a.k.a. CubeSat, into the Thermosphere. The scientific goal of this mission is to monitor over a period of up to nine months the prevailing conditions in this rather unknown part of Earth's atmosphere. Each of the 50 nanosatellites will be equipped with one of three possible scientific instruments: (i) a set of Langmuir probes, (ii) atomic oxygen measurement device, (iii) ion/neutral mass spectrometer. All satellites will be launched together and released in a string-of-pearls type fashion. It is predicted that the satellites will drift apart rather rapidly following the release. Therefore, the QB50 missions offers the possibility of a measurement grid in the thermosphere of unprecedented scope and accuracy. One of the satellites, named PEGASUS, is designed and build by a team of Austrian researches and students. PEGASUS will be equipped with the aforementioned Langmuir probes and will provide information about essential properties of the plasma in the thermosphere such as the electrontemperature and -density. In order to ensure the capability to collect and downlink the data over several months, PEGASUS requires about the same types of subsystems as one would find on large-scale satellites. This includes an attitude control system, an on-board computer, telecommunication devices, an electrical power systems allowing to harvest the solar power and either distribute or store it for later use, a thermal control system

  14. Midplane Ices in the Embedded Phase

    NASA Astrophysics Data System (ADS)

    Drozdovskaya, Maria; Walsh, Catherine; van Dishoeck, Ewine

    2015-08-01

    Icy grains in the midplanes of the youngest protoplanetary disks are the building blocks of protoplanets and protocometary bodies. Our Solar System shows significant chemical diversity. The chemical content is thought to be either inherited from the initial prestellar cloud, out of which our Solar System formed, or formed in-situ during the subsequent evolution of the protoplanetary disk. In this poster, the chemical analysis of midplanes in the context of globally evolving and collapsing star-forming systems will be presented. Previous studies compared various solid species relative to water ice in comets and towards young protostars [e.g., 1, 2, 3]. It remains unclear whether the overlap in abundances is just a coincidence or whether the origins of cometary ices are that of a prestellar cloud. For this work, an axisymmentric 2D semi-analytic collapse model [4], wavelength-dependent radiative transfer calculations with RADMC3D [5] and a comprehensive gas-grain chemical network [6] are used to pin down ice abundances in a midplane. The methanol content of protoplanetary disks will be presented [7], but also that of other main ice components, such as water, carbon monoxide and carbon dioxide [8]. Our models can be used to probe the validity of theories on the origin of chemical complexity and also to access the degree of processing upon inheritance into the forming disk.[1] Öberg K. I., Boogert A. C. A., Pontoppidan K. M., van den Broek S., van Dishoeck E. F., Bottinelli S., Blake G. A., Evans, II N. J., 2011, ApJ, 740, 109[2] Mumma M. J., Charnley S. B., 2011, ARA&A, 49, 471[3] Bockelée-Morvan D. et al., 2000, A&A, 353, 1101[4] Visser R., van Dishoeck E. F., Doty S. D., Dullemond C. P., 2009, A&A, 495, 881[5] Dullemond C. P., Dominik C., 2004, A&A, 417, 159[6] Walsh C., Millar T. J., Nomura H., Herbst E., Widicus Weaver S., Aikawa Y., Laas J. C., Vasyunin A. I., 2014, A&A, 563, A33[7] Drozdovskaya M. N., Walsh C., Visser R., Harsono D., van Dishoeck E. F., 2014

  15. Residence time of suspended particles in the Garonne River (SW France): indications derived from Th-234, Be-7 and Pb-210

    NASA Astrophysics Data System (ADS)

    Schmidt, Sabine; Saari, Hanna-Kaïsa

    2013-04-01

    -temporal variations. Temporal changes in Th-234/Pb-210 and 7Be/210Pb activity ratios (ARs) are complex, depending on river discharge and suspended matter load. To derive sediment ages from the present dataset, two distinct models have been used: 1/ based on radionuclide budget (Dominik et al, 1987, Earth Planet. Sci. Lett. 84 165-180), and 2/ using Be-7/Pb-210 ARs (Matisoff et al, 2005, Earth Surf. Process. Landforms 30 1191-1201). These age estimates will be detailed in order to discuss particulate transport processes in the Garonne river during contrasted hydrological periods (flood and low waters).

  16. The Cost-Optimal Distribution of Wind and Solar Generation Facilities in a Simplified Highly Renewable European Power System

    NASA Astrophysics Data System (ADS)

    Kies, Alexander; von Bremen, Lüder; Schyska, Bruno; Chattopadhyay, Kabitri; Lorenz, Elke; Heinemann, Detlev

    2016-04-01

    . "Investigation of balancing effects in long term renewable energy feed-in with respect to the transmission grid." Advances in Science and Research 12.1 (2015): 91-95, doi:10.5194/asr-12-91-2015 [2] Heide, Dominik, et al. "Reduced storage and balancing needs in a fully renewable European power system with excess wind and solar power generation." Renewable Energy 36.9 (2011): 2515-2523 [3] Rodriguez, R.A.: Weather-driven power transmission in a highly renewable European electricity network, PhD Thesis, Aarhus University, November 2014 [4] Pfluger, B. et al.: Tangible ways towards climate protection in the European Union (EU long-term scenarios 2050), Fraunhofer ISI, Karlsruhe, September 2011

  17. a New Generation Mining Head with Disc Tool of Complex Trajectory / GŁOWICA URABIAJĄCA Nowej Generacji Z NARZĘDZIAMI Dyskowymi O ZŁOŻONEJ Trajektorii

    NASA Astrophysics Data System (ADS)

    Gospodarczyk, Piotr; Kotwica, Krzysztof; Stopka, Grzegorz

    2013-12-01

    łowych warunkach pracy, ulegają przyspieszonemu zużyciu. Wpływa to na prędkość i koszty drążenia tych wyrobisk. W artykule przedstawiono opracowane w Katedrze MGPiT AGH Kraków nowe i innowacyjne rozwiązanie głowicy urabiającej, z narzędziami dyskowymi niesymetrycznymi o złożonej trajektorii, jako alternatywę dla standardowych organów frezujących. Opisano zalety zastosowanej metody urabiania z wykorzystaniem tzw. tylnego podcinaniaoraz zasadę budowy i pracy zaproponowanego rozwiązania przedmiotowej głowicy. Dla opracowania konstrukcji prototypowego egzemplarza tej głowicy koniecznym było określenie, na podstawie badań laboratoryjnych, założeń i wytycznych. Przedstawiono konstrukcję opracowanego specjalnego stanowiska laboratoryjnego do badania narzędzi dyskowych o złożonej trajektorii, założoną metodykę badawczą, przebieg badań oraz uzyskane wyniki. Analiza tych wyników umożliwiła określenie wyżej wymienionych założeń i wytycznych dla konstrukcji głowicy prototypowej. Na ich podstawie opracowano, we współpracy z Zakładami REMAG S.A. w Katowicach, projekt techniczny nowego rozwiązania głowicy, dostosowanej do zabudowy na ramieniu średniego kombajnu chodnikowego KR 150. Wykonany egzemplarz głowicy został poddany próbom na stanowisku badawczym na poligonie Zakładów REMAG i uzyskał pozytywne wyniki badań wstępnych.

  18. Cytomatrix synthesis in MDCK epithelial cells

    SciTech Connect

    Mitchell, J.J.; Low, R.B.; Woodcock-Mitchell, J.L. )

    1990-06-01

    Detailed information regarding the synthesis rates of individual protein components is important in understanding the assembly and dynamics of the cytoskeletal matrix of eukaryotic cells. As an approach to this topic, the dual isotope technique of Clark and Zak, was employed to measure fractional synthesis rates (FSRs) in growing and quiescent cultures of MDCK epithelial cells. Cell protein was labeled to equilibrium with (14C)leucine over several days and then pulse-labeled for 4 hours with (3H)leucine. FSRs (as percent per hour) were calculated from the 3H/14C ratio of cell extracts or individual proteins separated by two-dimensional polyacrylamide gel electrophoresis and the 3H/14C ratio of free leucine in the medium. Synthesis of total cell protein rose from approximately 1.4%/hour in quiescent cells to 3.5%/hour in the growing cultures. The latter rate was sufficient to account for the rate of protein accumulation and a low level of turnover in the growing cultures. The FSR of the buffered-Triton soluble extract was higher and the cytoskeletal FSR significantly lower than that for total protein in quiescent monolayers. This difference, however, was not observed in growing cultures. A distinct pattern of differences was seen in the FSRs of individual cytoskeletal proteins in the quiescent cultures. Vimentin synthesis was significantly lower than that of the keratins and the keratin FSRs were not obviously matched in pairwise fashion. Unexpectedly, the FSRs of alpha- and beta-tubulin diverged in quiescent cells with alpha-tubulin turnover exceeding beta-tubulin. Likewise, components of the microfilament lattice showed unequal fractional synthesis rates, myosin and alpha-actinin being faster than actin. In addition, the FSR for globular actin exceeded that of the cytoskeletal associated form.

  19. Best Practice Guide for the Treatment of Nightmare Disorder in Adults

    PubMed Central

    Aurora, R. Nisha; Zak, Rochelle S.; Auerbach, Sanford H.; Casey, Kenneth R.; Chowdhuri, Susmita; Karippot, Anoop; Maganti, Rama K.; Ramar, Kannan; Kristo, David A.; Bista, Sabin R.; Lamm, Carin I.; Morgenthaler, Timothy I.

    2010-01-01

    Summary of Recommendations: Prazosin is recommended for treatment of Posttraumatic Stress Disorder (PTSD)-associated nightmares. Level A Image Rehearsal Therapy (IRT) is recommended for treatment of nightmare disorder. Level A Systematic Desensitization and Progressive Deep Muscle Relaxation training are suggested for treatment of idiopathic nightmares. Level B Venlafaxine is not suggested for treatment of PTSD-associated nightmares. Level B Clonidine may be considered for treatment of PTSD-associated nightmares. Level C The following medications may be considered for treatment of PTSD-associated nightmares, but the data are low grade and sparse: trazodone, atypical antipsychotic medications, topiramate, low dose cortisol, fluvoxamine, triazolam and nitrazepam, phenelzine, gabapentin, cyproheptadine, and tricyclic antidepressants. Nefazodone is not recommended as first line therapy for nightmare disorder because of the increased risk of hepatotoxicity. Level C The following behavioral therapies may be considered for treatment of PTSD-associated nightmares based on low-grade evidence: Exposure, Relaxation, and Rescripting Therapy (ERRT); Sleep Dynamic Therapy; Hypnosis; Eye-Movement Desensitization and Reprocessing (EMDR); and the Testimony Method. Level C The following behavioral therapies may be considered for treatment of nightmare disorder based on low-grade evidence: Lucid Dreaming Therapy and Self-Exposure Therapy. Level C No recommendation is made regarding clonazepam and individual psychotherapy because of sparse data. Citation: Aurora RN; Zak RS; Auerbach SH; Casey KR; Chowduri S; Krippot A; Maganti RK; Ramar K; Kristo DA; Bista SR; Lamm CI; Morgenthaler TI. Best practice guide for the treatment of nightmare disorder in adults. J Clin Sleep Med 2010;6(4):389-401. PMID:20726290

  20. Room Temperature Line Lists for CO_2 Isotopologues with AB Initio Computed Intensities

    NASA Astrophysics Data System (ADS)

    Zak, Emil; Tennyson, Jonathan; Polyansky, Oleg; Lodi, Lorenzo; Zobov, Nikolay Fedorovich; Tashkun, Sergey; Perevalov, Valery

    2016-06-01

    We report 13 room temperature line lists for all major CO_2 isotopologues, covering 0-8000 wn. These line lists are a response to the need for line intensities of high, preferably sub-percent, accuracy by remote sensing experiments. Our scheme encompasses nuclear motion calculations supported by critical reliability analysis of the generated line intensities. Rotation-vibration wavefunctions and energy levels are computed using DVR3D and a high quality semi-empirical potential energy surface (PES) [1], followed by computation of intensities using a fully ab initio dipole moment surface (DMS). Cross comparison of line lists calculated using pairs of high-quality PES's and DMS's is used to assess imperfections in the PES, which lead to unreliable transition intensities between levels involved in resonance interactions. Four line lists are computed for each isotopologue to quantify sensitivity to minor distortions of the PES/DMS. This provides an estimate of the contribution to the overall line intensity error introduced by the underlying PES. Reliable lines are benchmarked against recent state-of-the-art measurements [2] and HITRAN-2012 supporting the claim that the majority of line intensities for strong bands are predicted with sub-percent accuracy [3]. Accurate line positions are generated using an effective Hamiltonian [4]. We recommend use of these line lists for future remote sensing studies and inclusions in databases. X. Huang, D. W. Schwenke, S. A. Tashkun, T. J. Lee, J. Chem. Phys. 136, 124311, 2012. O. L. Polyansky, K. Bielska, M. Ghysels, L. Lodi, N. F. Zobov, J. T. Hodges, J. Tennyson, PRL, 114, 243001, 2015. E. Zak, J. Tennyson, O. L. Polyansky, L. Lodi, S. A. Tashkun, V. I. Perevalov, JQSRT, in press and to be submitted. S. A. Tashkun, V. I. Perevalov, R. R. Gamache, J. Lamouroux, JQSRT, 152, 45-73, 2015.

  1. Constructing a Weyl semimetal by stacking one-dimensional topological phases

    NASA Astrophysics Data System (ADS)

    Ganeshan, Sriram; Das Sarma, S.

    2015-03-01

    Topological semimetals in three-dimensions (e.g., a Weyl semimetal) can be built by stacking two-dimensional topological phases. The interesting aspect of such a construction is that even though the topological building blocks in the low dimension may be gapped, the higher dimensional semimetallic phase emerges as a gapless critical point of a topological phase transition between two distinct insulating phases. In this work, we extend this idea by constructing three-dimensional topological semimetallic phases akin to Weyl systems by stacking one-dimensional Aubry-Andre-Harper (AAH) lattice tight-binding models with nontrivial topology. The generalized AAH model is a family of one-dimensional tight-binding models with cosine modulations in both hopping and on-site energy terms. In this paper, we present a two-parameter generalization of the AAH model that can access topological phases in three dimensions within a unified framework. We show that the π -flux state of this two-parameter AAH model manifests three-dimensional topological semimetallic phases where the topological features are embedded in one dimension. The topological nature of the band touching points of the semimetallic phase in 3D is explicitly established both analytically and numerically from the 1D perspective. This dimensional reduction provides a simple protocol to experimentally construct the three-dimensional Brillouin zone of the topological semimetallic phases using "legos" of simple 1D double well optical lattices. We also propose Zak phase imaging of optical lattices as a tool to capture the topological nature of the band touching points. Our work provides a theoretical connection between the commensurate AAH model in 1D and Weyl semimetals in 3D, and points toward practical methods for the laboratory realization of such three-dimensional topological systems in atomic optical lattices.

  2. Activation of the Classical Mitogen-Activated Protein Kinases Is Part of the Shiga Toxin-Induced Ribotoxic Stress Response and May Contribute to Shiga Toxin-Induced Inflammation

    PubMed Central

    Ahluwalia, Amrita; Schimmel, Jennifer J.; Rogers, Arlin B.; Leong, John M.; Thorpe, Cheleste M.

    2015-01-01

    Infection with enterohemorrhagic Escherichia coli (EHEC) can result in severe disease, including hemorrhagic colitis and the hemolytic uremic syndrome. Shiga toxins (Stx) are the key EHEC virulence determinant contributing to severe disease. Despite inhibiting protein synthesis, Shiga toxins paradoxically induce the expression of proinflammatory cytokines from various cell types in vitro, including intestinal epithelial cells (IECs). This effect is mediated in large part by the ribotoxic stress response (RSR). The Shiga toxin-induced RSR is known to involve the activation of the stress-activated protein kinases (SAPKs) p38 and JNK. In some cell types, Stx also can induce the classical mitogen-activated protein kinases (MAPKs) or ERK1/2, but the mechanism(s) by which this activation occurs is unknown. In this study, we investigated the mechanism by which Stx activates ERK1/2s in IECs and the contribution of ERK1/2 activation to interleukin-8 (IL-8) expression. We demonstrate that Stx1 activates ERK1/2 in a biphasic manner: the first phase occurs in response to StxB1 subunit, while the second phase requires StxA1 subunit activity. We show that the A subunit-dependent ERK1/2 activation is mediated through ZAK-dependent signaling, and inhibition of ERK1/2 activation via the MEK1/2 inhibitors U0126 and PD98059 results in decreased Stx1-mediated IL-8 mRNA. Finally, we demonstrate that ERK1/2 are activated in vivo in the colon of Stx2-intoxicated infant rabbits, a model in which Stx2 induces a primarily neutrophilic inflammatory response. Together, our data support a role for ERK1/2 activation in the development of Stx-mediated intestinal inflammation. PMID:26483408

  3. Transdifferentiation of mesenchymal stem cells-derived adipogenic-differentiated cells into osteogenic- or chondrogenic-differentiated cells proceeds via dedifferentiation and have a correlation with cell cycle arresting and driving genes.

    PubMed

    Ullah, Mujib; Stich, Stefan; Notter, Michael; Eucker, Jan; Sittinger, Michael; Ringe, Jochen

    2013-02-01

    It is generally accepted that after differentiation bone marrow mesenchymal stem cells (MSC) become lineage restricted and unipotent in an irreversible manner. However, current results imply that even terminally differentiated cells transdifferentiate across lineage boundaries and therefore act as a progenitor cells for other lineages. This leads to the questions that whether transdifferentiation occurs via direct cell-to-cell conversion or dedifferentiation to a progenitor cells and subsequent differentiation, and whether MSC potency decreases or increases during differentiation. To address these questions, MSC were differentiated into adipogenic lineage cells, followed by dedifferentiation. The process of dedifferentiation was also confirmed by single cell clonal analysis. Finally the dedifferentiated cells were used for adipogenesis, osteogenesis and chondrogenesis. Histology, FACS, qPCR and GeneChip analyses of undifferentiated MSC, adipogenic-differentiated and dedifferentiated cells were performed. Interestingly, gene profiling and bioinformatics demonstrated that upregulation (DHCR24, G0S2, MAP2K6, SESN3) and downregulation (DST, KAT2, MLL5, RB1, SMAD3, ZAK) of distinct genes have an association with cell cycle arrest in adipogenic-differentiated cells and perhaps narrow down the lineage potency. However, the upregulation (CCND1, CHEK, HGF, HMGA2, SMAD3) and downregulation (CCPG1, RASSF4, RGS2) of these genes have an association with cell cycle progression and maybe motivate dedifferentiation of adipogenic-differentiated cells. We found that dedifferentiated cells have a multilineage potency comparable to MSC, and also observed the associative role of proliferation genes with cell cycle arrest and progression. Concluded, our results indicate that transdifferentiation of adipogenic-differentiated cells into osteogenic- or chondrogenic-differentiated cells proceeds via dedifferentiation and correlates with cell cycle arresting and deriving genes. Regarding

  4. PREFACE: XXXth International Colloquium on Group Theoretical Methods in Physics (ICGTMP) (Group30)

    NASA Astrophysics Data System (ADS)

    Brackx, Fred; De Schepper, Hennie; Van der Jeugt, Joris

    2015-04-01

    participants at the Group30 colloquium from 46 different countries. This high number of participants makes the 30th edition of ICGTMP one of the most successful meetings of the series. We were particularly happy with the attendance of 32 students and many young postdocs: this is promising for the future of the research field and of the colloquium series. The attraction of young scientists was promoted by a reduced participation fee, the availability of cheap accommodation in the University Student Guest House, grants from a US-NSF project and grants from the Organising Committee supporting participants from countries with limited financial resources. The colloquium brought together international top researchers, with a variety of different backgrounds but with "group theoretical or algebraic methods" as common ground. The selection of plenary speakers and topics was made by the Organizing Committee, following the suggestions of the International Advisory Committee (consisting of prominent scientists in their domain), and ensuring the diversity of the subjects treated. There were 11 plenary talks, given as well by distinguished world experts as by young rising stars: Matthias Christandl, Alberto De Sole, Rui Loja Fernandes, François Gay-Balmaz, Gitta Kutyniok, Amiram Leviatan, Karl-Hermann Neeb, Christoph Schweigert, Yuji Tachikawa, Luc Vinet and Joshua Zak. Next to the plenary talks, there were 170 talks in six parallel sessions and 10 poster presentations. All scientific activities took place in the Joseph Plateau Building of the Faculty of Engineering and Architecture of Ghent University, a historical building conveniently located in the city centre of Ghent. In this building we could make use of the main lecture hall (400 seats) for the plenary lectures, six lecture rooms for parallel sessions, two offices for organizational activities and registrations, two PC-rooms and a large foyer for coffee breaks, book exhibitions and the poster session. As part of the colloquium, a

  5. N=(0,2) deformation of the CP(1) model: Two-dimensional analog of N=1 Yang-Mills theory in four dimensions

    NASA Astrophysics Data System (ADS)

    Cui, Xiaoyi; Shifman, M.

    2012-02-01

    We consider two-dimensional N=(0,2) sigma models with the CP(1) target space. A minimal model of this type has one left-handed fermion. Nonminimal extensions contain, in addition, Nf right-handed fermions. Our task is to derive expressions for the β functions valid to all orders. To this end we use a variety of methods: (i) perturbative analysis; (ii) instanton calculus; (iii) analysis of the supercurrent supermultiplet (the so-called hypercurrent) and its anomalies, and some other arguments. All these arguments, combined, indicate a direct parallel between the heterotic N=(0,2) CP(1) models and four-dimensional super-Yang-Mills theories. In particular, the minimal N=(0,2) CP(1) model is similar to N=1 supersymmetric gluodynamics. Its exact β function can be found; it has the structure of the Novikov-Shifman-Vainshtein-Zakharov (NSVZ) β function of supersymmetric gluodynamics. The passage to nonminimal N=(0,2) sigma models is equivalent to adding matter. In this case an NSVZ-type exact relation between the β function and the anomalous dimensions γ of the “matter” fields is established. We derive an analog of the Konishi anomaly. At large Nf our β function develops an infrared fixed point at small values of the coupling constant (analogous to the Banks-Zaks fixed point). Thus, we reliably predict the existence of a conformal window. At Nf=1 the model under consideration reduces to the well-known N=(2,2) CP(1) model.

  6. Flow of the □R Weyl anomaly

    NASA Astrophysics Data System (ADS)

    Prochazka, Vladimir; Zwicky, Roman

    2017-08-01

    An important aspect of Weyl anomalies is that they encode information on the irreversibility of the renormalization group flow. We consider, Δ b ¯=b¯UV-b¯IR, the difference of the ultraviolet and infrared value of the □R -term of the Weyl anomaly. The quantity is related to the fourth moment of the trace of the energy momentum tensor correlator for theories which are conformal at both ends. Subtleties arise for nonconformal fixed points as might be the case for infrared fixed points with broken chiral symmetry. Provided that the moment converges, Δ b ¯ is then automatically positive by unitarity. Written as an integral over the renormalization scale, flow-independence follows since its integrand is a total derivative. Furthermore, using a momentum subtraction scheme (MOM) the 4D Zamolodchikov-metric is shown to be strictly positive beyond perturbation theory and equivalent to the metric of a conformal manifold at both ends of the flow. In this scheme b ¯(μ ) can be extended outside the fixed point to a monotonically decreasing function. The ultraviolet finiteness of the fourth moment enables us to define a scheme for the δ L ˜b0R2-term, for which the R2-anomaly vanishes along the flow. In the MOM- and the R2-scheme, b ¯(μ ) is shown to satisfy a gradient flow type equation. We verify our findings in free field theories, higher derivative theories and extend Δ b ¯ and the Euler flow Δ βa for a Caswell-Banks-Zaks fixed point for QCD-like theories to next-to-next-to leading order using a recent ⟨G2G2 ⟩-correlator computation.

  7. Trace Element Condensation in Circumstellar Envelopes of Carbon Stars

    NASA Astrophysics Data System (ADS)

    Lodders, K.; Fegley, B., Jr.

    1992-07-01

    It is now well established that meteorites contain reduced presolar grains, such as graphite and silicon carbide (SiC), which are probably formed by condensation of dust in the circumstellar envelopes of carbon-rich AGB stars. Here we model condensation in envelopes of carbon stars, with an emphasis on trace elements. Since absolute elemental abundances in stellar atmospheres are generally not known, we assume solar abundances (Anders and Grevesse 1989), except for carbon. A C/O ratio of 2, consistent with the mean and median values of 2.1 and 1.8 respectively, for 61 carbon stars (Gow 1977) was used. The C/O ratio was increased by adding carbon because astrophysicists believe that carbon produced in helium-burning zones may be mixed to the surfaces of C stars (e.g. Lucy 1976). We used physical parameters for the circumstellar shell of the high mass-loss rate, prototypical carbon star IRC +10216 (e.g. Keady et al. 1988, Dominik et al. 1990) and theoretical considerations by Salpeter (1974a,b) to construct a P-T-model of the envelope (see Fig. 1). Thermodynamic equilibrium condensation calculations for a reduced gas include ~600 gaseous and solid compounds of the elements H, C, N, O, S, P, F, Cl, Fe, Mg, Al, Ti, Si, Ca, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and REE. Refractory oxides, sulfides, nitrides, and carbides were considered as condensates. The calculations were done from T = 800 to 2500 K, and P= 10^-5 to 10^-13 bars. The effects of nucleation on condensation temperatures were calculated using the nucleation model discussed by Salpeter (1974a,b) and Cameron and Fegley (1982). The temperature drop required for condensation depends on (P,T, density) in the expanding envelope and also on the abundance, density, and surface energy (Es) of the nucleating compound. The range of E(sub)s values for NaCl-type carbides are about 800-1700 erg/cm^2 (Livey & Murray 1956); however, these data are generally poorly known. Another important variable is the sticking coefficient (s

  8. Low-velocity collision behaviour of clusters composed of sub-millimetre sized dust aggregates

    NASA Astrophysics Data System (ADS)

    Brisset, J.; Heißelmann, D.; Kothe, S.; Weidling, R.; Blum, J.

    2017-07-01

    ranged from 4.9 to 23.8 cm s-1 for the same aggregates with an average of 10.1 ± 3.2 cm s-1 for reduced masses ranging from 1.2 × 10-5 to 1.2 × 10-3 with an average value of 4.2 ± 2.4 × 10-4 g. From the restructuring and fragmentation of clusters composed of dust aggregates colliding with the aluminium cell walls, we derived a collision recipe for dust aggregates ( 100 μm) following the model of Dominik & Tielens (1997, ApJ, 480, 647) developed for microscopic particles. We measured a critical rolling energy of 1.8 ± 0.9 × 10-13 J and a critical breaking energy of 3.5 ± 1.5 × 10-13 J for 100 μm-sized non-compacted aggregates. A movie associated to Fig. 3 is available at http://www.aanda.org

  9. Impact of river regulation on potential sediment mobilization and transport in an Alpine catchment

    NASA Astrophysics Data System (ADS)

    Costa, Anna; Molnar, Peter; Lane, Stuart N.; Bakker, Maarten

    2015-04-01

    The upper Rhône basin (upstream of Lake Geneva) has been heavily affected by human activities during the last century. The most evident impacts are related to river regulation, specifically flow impoundement, flow abstraction and channelization. In the last century and mainly since 1960, several large dams have been built along the main tributaries of the Rhône River, resulting in the water storage of a volume equal to 20% of the total annual river flow. The dams are part of hydropower systems which abstract water from streams and transfer it through complex networks (intakes, tunnels and pumping stations) to the reservoirs. Hydropower production leads to regulated flow in the Rhône: mostly an increase of winter flows, a reduction of summer flows, and a decrease of flood peaks. The sediment supply into Lake Geneva has decreased following dam construction (Loizeau & Dominik, 2000) due to the storage of sediment in upstream reservoirs, in rivers with reduced sediment transport capacity due to flow abstraction, and due to the development of sediment mining. Our hypothesis is that streamflow regulation itself has dramatically impacted the sediment transport dynamics of the system. We investigate the impacts of flow regulation on the sediment transport regime, by analysing the effects on potential sediment transport capacity (bedload). By the use of different bedload transport formulae (Meyer-Peter Müller, Wilcock and Crowe), the potential sediment transport capacity is computed at different cross sections within the basin. Potential sediment mobility occurs when the applied bed shear stress exceeds a critical value, τ>τc. The applied bed shear stress is computed as τ=ρghS, with water depth (h) measured from rating curves. We obtain an estimate of the energy slope (S) from the analysis of the river cross section, assuming uniform flow. The critical value of bed shear stress τc is computed using empirical formulae as a function of the grain diameter (ds). To

  10. Black Holes Lead Galaxy Growth, New Research Shows

    NASA Astrophysics Data System (ADS)

    2009-01-01

    Astronomers may have solved a cosmic chicken-and-egg problem -- the question of which formed first in the early Universe -- galaxies or the supermassive black holes seen at their cores. "It looks like the black holes came first. The evidence is piling up," said Chris Carilli, of the National Radio Astronomy Observatory (NRAO). Carilli outlined the conclusions from recent research done by an international team studying conditions in the first billion years of the Universe's history in a lecture presented to the American Astronomical Society's meeting in Long Beach, California. Gas in Distant Galaxy VLA image (right) of gas in young galaxy seen as it was when the Universe was only 870 million years old. CREDIT: NRAO/AUI/NSF, SDSS Full-size JPEG, 323 KB PDF file, 180 KB Galaxy image, no annotation, JPEG 21 KB Earlier studies of galaxies and their central black holes in the nearby Universe revealed an intriguing linkage between the masses of the black holes and of the central "bulges" of stars and gas in the galaxies. The ratio of the black hole and the bulge mass is nearly the same for a wide range of galactic sizes and ages. For central black holes from a few million to many billions of times the mass of our Sun, the black hole's mass is about one one-thousandth of the mass of the surrounding galactic bulge. "This constant ratio indicates that the black hole and the bulge affect each others' growth in some sort of interactive relationship," said Dominik Riechers, of Caltech. "The big question has been whether one grows before the other or if they grow together, maintaining their mass ratio throughout the entire process." In the past few years, scientists have used the National Science Foundation's Very Large Array radio telescope and the Plateau de Bure Interferometer in France to peer far back in the 13.7 billion-year history of the Universe, to the dawn of the first galaxies. "We finally have been able to measure black-hole and bulge masses in several galaxies seen

  11. PREFACE: Nano- and microfluidics Nano- and microfluidics

    NASA Astrophysics Data System (ADS)

    Jacobs, Karin

    2011-05-01

    compressible fluids Kerstin Falk and Klaus Mecke Wetting, roughness and flow boundary conditions Olga I Vinogradova and Aleksey V Belyaev Molecular transport and flow past hard and soft surfaces: computer simulation of model systems F Léonforte, J Servantie, C Pastorino, and M Müller Simulations of slip flow on nanobubble-laden surfaces J Hyväluoma, C Kunert and J Harting Electrophoretic transport of biomolecules across liquid-liquid interfaces Thomas Hahn, Götz Münchow and Steffen Hardt Wetting morphologies and their transitions in grooved substrates Ralf Seemann, Martin Brinkmann, Stephan Herminghaus, Krishnacharya Khare, Bruce M Law, Sean McBride, Konstantina Kostourou, Evgeny Gurevich, Stefan Bommer, Carsten Herrmann and Dominik Michler Imbibition in mesoporous silica: rheological concepts and experiments on water and a liquid crystal Simon Gruener, and Patrick Huber Theory and simulations of water flow through carbon nanotubes: prospects and pitfalls Douwe Jan Bonthuis, Klaus F Rinne, Kerstin Falk, C Nadir Kaplan, Dominik Horinek, A Nihat Berker, Lydéric Bocquet, and Roland R Netz Structure and flow of droplets on solid surfaces P Müller-Buschbaum, D Magerl, R Hengstler, J-F Moulin, V Körstgens, A Diethert, J Perlich, S V Roth, M Burghammer, C Riekel, M Gross, F Varnik, P Uhlmann, M Stamm, J M Feldkamp and C G Schroer Stability and dynamics of droplets on patterned substrates: insights from experiments and lattice Boltzmann simulations F Varnik, M Gross, N Moradi, G Zikos, P Uhlmann, P Müller-Buschbaum, D Magerl, D Raabe, I Steinbach and M Stamm Micro-capsules in shear flow R Finken, S Kessler and U Seifert Micro-rheology on (polymer-grafted) colloids using optical tweezers C Gutsche, M M Elmahdy, K Kegler, I Semenov, T Stangner, O Otto, O Ueberschär, U F Keyser, M Krueger, M Rauscher, R Weeber, J Harting, Y W Kim, V Lobaskin, R R Netz, and F Kremer Dynamics of colloids in confined geometries L Almenar and M Rauscher Dynamics of red blood cells and vesicles in

  12. Greenhouse gas emissions from an abandoned peatland in central Belarus during the first year of rewetting

    NASA Astrophysics Data System (ADS)

    Chuvashova, H.; Minke, M.; Burlo, A.; Thiele, A.; Augustin, J.; Yarmashuk, T.; Tichonov, V.; Liashchynskaya, N.; Kuzmin, Vl.

    2012-04-01

    Peatland restoration by inundation of drained fen grasslands can lead to very high methane emissions in the first years (M. Hahn-Schöfl et al, 2011). Due to a lack of other studies on the GHG emissions of fen forbs and meadows during the first years after flooding there is the worry to create methane plants by restoring such sites. Within the BMU-ICI financed project "Restoring Peatlands and applying Concepts for Sustainable Managements in Belarus - Climate Change Mitigation with Economic and Biodiversity Benefits" we selected the mesotrophic fen Bartenikha as a typical petland for central Belarus as study site. The peatland Bartenikha was drained in 1990 and used for peat extraction till 1999. Subsequently the peatland got abandoned and a meadow dominated by Agrostis stolonifera emerged in its SW part. In September 2010 the meadow was unexpectedly flooded by the beaver and the forbs died. During one year the water level changed from nearly 10 cm below surface to nearly 50 cm above surface. In 2011 only detritus was left from the former vegetation, but new species, beside some Chara, were still not established. We studied the effect of rewetting on the emission of carbon dioxide and methane during the period from September 2010 till September 2011 using the closed chamber method. Methane release during autumn, winter and early spring was still low. Substantially higher emissions of Methane are observed since June with highest rates in July when the water level was lower than usually, i.e. 20 cm above the surface and the temperature was high. In total Methane emissions per year were lower as expected. Carbon dioxide release was low during the whole year because of high water level but a dependence of emissions on temperature was detected. Altogether greenhouse gas emissions from the rewetted peatland were not high in the first year of flooding. Hahn-Schöfl M, Zak D., Minke M., Gelbrecht J., Augustin J., and Freibauer A. Organic sediment formed during inundation of

  13. Effect of destablized reactions using lithium amide (LiNH2) and doping using titanium based catalyst on the desorption characteristics of lithuim aluminium hydride (LiAlH4)

    NASA Astrophysics Data System (ADS)

    Paravasthu, Siddharth

    In the past few decades there has been a tremendous increase in hydrogen storage research. Numerous materials and material systems have been studied as potential candidates for hydrogen storage, but unfortunately none of those materials demonstrate enough hydrogen releasing capacity under suitable temperature range to be used for hydrogen storage. Research promises to unlock the potential of these materials and ultimately lead to the commercialization of this technology. LiAlH4 is one of those materials that have been exclusively studied as a candidate for hydrogen storage due to its high theoretical hydrogen storage capacity, and its ability to release hydrogen in more than one step at different temperature ranges. Jun Lu and Zhigang Zak Fang studied the effects of titanium based catalyst (TiCl3.1/3AlCl3) and destabilization reactions using LiNH2 on LiAlH4, but did not demonstrate the effects of ball milling on the system. In the present work we have investigated the effects of ball milling, and the effects of destabilization reaction using LiNH2 on the hydrogen release characteristics of LiAlH4 doped with TiCl3. The current market scenario for fuel cell technology and the possibility and consequences of introducing the current system in the market has been briefly discussed. X-ray powder diffraction, thermo-gravimetric analysis and scanning electron microscopy were employed for the characterization of the samples. Both the compounds LiNH2, and TiCl3 worked in effecting the dehydrogenation kinetics of LiAlH4. The duration of ball milling required to affect the dehydrogenation kinetics of LiAlH 4 using TiCl3 was optimized. A hydrogen release of 7.3 wt% was observed from the final system i.e. (LiAlH4 LiNH2 doped with 2% TiCl3) at temperatures below 400°C.

  14. A pharmacogenetic signature of high response to Copaxone in late-phase clinical-trial cohorts of multiple sclerosis.

    PubMed

    Ross, Colin J; Towfic, Fadi; Shankar, Jyoti; Laifenfeld, Daphna; Thoma, Mathis; Davis, Matthew; Weiner, Brian; Kusko, Rebecca; Zeskind, Ben; Knappertz, Volker; Grossman, Iris; Hayden, Michael R

    2017-05-31

    Copaxone is an efficacious and safe therapy that has demonstrated clinical benefit for over two decades in patients with relapsing forms of multiple sclerosis (MS). On an individual level, patients show variability in their response to Copaxone, with some achieving significantly higher response levels. The involvement of genes (e.g., HLA-DRB1*1501) with high inter-individual variability in Copaxone's mechanism of action (MoA) suggests the potential contribution of genetics to treatment response. This study aimed to identify genetic variants associated with Copaxone response in patient cohorts from late-phase clinical trials. Single nucleotide polymorphisms (SNPs) associated with high and low levels of response to Copaxone were identified using genome-wide SNP data in a discovery cohort of 580 patients from two phase III clinical trials of Copaxone. Multivariable Bayesian modeling on the resulting SNPs in an expanded discovery cohort with 1171 patients identified a multi-SNP signature of Copaxone response. This signature was examined in 941 Copaxone-treated MS patients from seven independent late-phase trials of Copaxone and assessed for specificity to Copaxone in 310 Avonex-treated and 311 placebo-treated patients, also from late-phase trials. A four-SNP signature consisting of rs80191572 (in UVRAG), rs28724893 (in HLA-DQB2), rs1789084 (in MBP), and rs139890339 (in ZAK(CDCA7)) was identified as significantly associated with Copaxone response. Copaxone-treated signature-positive patients had a greater reduction in annualized relapse rate (ARR) compared to signature-negative patients in both discovery and independent cohorts, an effect not observed in Avonex-treated patients. Additionally, signature-positive placebo-treated cohorts did not show a reduction in ARR, demonstrating the predictive as opposed to prognostic nature of the signature. A 10% subset of patients, delineated by the signature, showed marked improvements across multiple clinical parameters

  15. Oxygen Isotope Perspectives on Magma Sources and Pluton Assembly in Convergent Margin Batholiths

    NASA Astrophysics Data System (ADS)

    Lackey, J.

    2008-12-01

    hierarchy of magma systems operated in the SNB and that sources were periodically reset by tectonic modification. [1] Lackey et al. 2008, J. Pet. [2] Coleman et el. 2004 Geol.; [3] Zak et al. 2007, GSAB.; [4] Matzel et al. 2007, GCA; [5] Ducea, 2001, GSA Today

  16. Use of Cad Systems in Testing the Collision of Underground Transportation Means / Zastosowanie systemów Cad w badaniach kolizyjności środków transportu podziemnego

    NASA Astrophysics Data System (ADS)

    Dudek, Marek

    2013-06-01

    A concept of use of CAD systems in testing collision of underground transportation means is presented. Reasons for undertaking this problem are given with end users identified. The concept of the system for collision analyses of transported loads is described. Examples of collision analysis during transportation of powered roof support are given. Presented system is designed to aid planning, organizational and training activities undertaken in management of transportation safety in mines. It will be also possible to use software resources, developed within the system as the didactic material as regards safe transportation process, which include hazards to the employees working in the area of transportation operations. Developed prototype of a system for testing the collision of underground transportation means was positively assessed by employees of the Coal Company, JSC - industrial partner of KOMAG. This prototype is continuously improved and adapted for commercial implementation in the selected coal mines. W pracy przedstawiono koncepcję zastosowania systemów CAD w badaniach kolizyjności środków transportu podziemnego. Określono przyczyny podjęcia tematu oraz zidentyfikowano końcowych użytkowników. Zaprezentowano koncepcję systemu do analiz kolizyjności transportowanych ładunków. Pokazano przykłady analizy kolizyjności podczas transportu sekcji obudowy zmechanizowanej. Przedstawiony system przeznaczony jest do wspomagania działań planistycznych, organizacyjnych i szkoleniowych podejmowanych w zarządzaniu bezpieczeństwem transportu w zakładach górniczych. Opracowane w ramach systemu zasoby programowe będzie można również wykorzystać jako materiał dydaktyczny z zakresu bezpieczeństwa pracy w transporcie, uwzględniający zagrożenia dla pracowników pracujących w bezpośredniej strefie prac transportowych. Opracowany prototyp systemu do badania kolizyjności środków transportu podziemnego został pozytywnie oceniony przez pracownik

  17. Physiological strain in the Hungarian mining industry: The impact of physical and psychological factors.

    PubMed

    Varga, József; Nagy, Imre; Szirtes, László; Pórszász, János

    2016-01-01

    The objectives of these investigations completed on workplaces in the Hungarian mining industry were to characterize the physiological strain of workers by means of work pulse and to examine the effects of work-related psychological factors. Continuous heart rate (HR) recording was completed on 71 miners over a total of 794 shifts between 1987 and 1992 in mining plants of the Hungarian mining industry using a 6-channel recorder - Bioport (ZAK, Germany). The work processes were simultaneously documented by video recording along with drawing up the traditional ergonomic workday schedule. All workers passed health evaluation for fitness for work. The effects of different psychological factors (simulated danger, "instrument stress," presence of managers, and effect of prior involvement in accidents as well as different mining technologies and work place illumination) on the work pulse were evaluated. The statistical analysis was completed using SPSS software (version 13.0, SPSS Inc., USA). The work-related physiological strain differed between work places with different mining technologies in groups of 12-18 workers. The work pulse was lowest in bauxite mining (ΔHR = 22±8.9 bpm) and highest in drift drilling in dead rock with electric drilling machine (ΔHR = 30±6.9 bpm). During sham alarm situation the work pulse was significantly higher than during normal activities with the same physical task (ΔHR = 36.7±4.8 bpm vs. 25.8±1.6 bpm, p < 0.001). When work was performed under different psychological stress, the work pulse was consistently higher, while improving the work place illumination decreased the physiological strain appreciably (ΔHR (median, 25-75 percentiles) = 23, 20-26 bmp vs. 28, 25-31.3 bpm, p < 0.001). Recording the heart rate during whole-shift work along with the work conditions gives reliable results and helps isolating factors that contribute to increased strain. The results can be used to implement preventive and health promotion measures. This

  18. Technidilaton at the conformal edge

    SciTech Connect

    Hashimoto, Michio; Yamawaki, Koichi

    2011-01-01

    Technidilaton (TD) was proposed long ago in the technicolor near criticality/conformality. To reveal the critical behavior of TD, we explicitly compute the nonperturbative contributions to the scale anomaly <{theta}{sub {mu}}{sup {mu}>} and to the technigluon condensate <{alpha}G{sub {mu}{nu}}{sup 2}>, which are generated by the dynamical mass m of the technifermions. Our computation is based on the (improved) ladder Schwinger-Dyson equation, with the gauge coupling {alpha} replaced by the two-loop running coupling {alpha}({mu}) having the Caswell-Banks-Zaks infrared fixed point {alpha}{sub *}: {alpha}({mu}){approx_equal}{alpha}={alpha}{sub *} for the infrared region m<{mu}<{Lambda}{sub TC}, where {Lambda}{sub TC} is the intrinsic scale (analogue of {Lambda}{sub QCD} of QCD) relevant to the perturbative scale anomaly. We find that -<{theta}{sub {mu}}{sup {mu}}>/m{sup 4}{yields}const{ne}0 and <{alpha}G{sub {mu}}{nu}{sup 2}>/m{sup 4}{yields}({alpha}/{alpha}{sub cr}-1){sup -3/2}{yields}{infinity} in the criticality limit m/{Lambda}{sub TC}{approx}exp(-{pi}/({alpha}/{alpha}{sub cr}-1){sup 1/2}){yields}0 ({alpha}={alpha}{sub *}=>{alpha}{sub cr}, or N{sub f} approaches N{sub f}{sup cr}) ('conformal edge'). Our result precisely reproduces the formal identity <{theta}{sub {mu}}{sup {mu}>}=({beta}({alpha})/4{alpha}{sup 2})<{alpha}G{sub {mu}{nu}}{sup 2}>, where {beta}({alpha})={Lambda}{sub TC}({partial_derivative}{alpha}/{partial_derivative}{Lambda}{sub TC})=-(2{alpha}{sub cr}/{pi}){center_dot}({alpha}/{alpha}{sub cr}-1){sup 3/2} is the nonperturbative beta function corresponding to the above essential singularity scaling of m/{Lambda}{sub TC}. Accordingly, the partially conserved dilatation current implies (M{sub TD}/m){sup 2}(F{sub TD}/m){sup 2}=-4<{theta}{sub {mu}}{sup {mu}}>/m{sup 4}{yields}const{ne}0 at criticality limit, where M{sub TD} is the mass of TD and F{sub TD} the decay constant of TD. We thus conclude that at criticality limit the TD could become a ''true

  19. Regional model studies of the atmospheric dispersion of fine volcanic ash after the eruption of Eyjafjallajoekull

    NASA Astrophysics Data System (ADS)

    Langmann, B.; Hort, M. K.

    2010-12-01

    During the eruption of Eyjafjallajoekull on Iceland in April/May 2010 air traffic over Europe was repeatedly interrupted because of volcanic ash in the atmosphere. This completely unusual situation in Europe leads to the demand of improved crisis management, e.g. European wide regulations of volcanic ash thresholds and improved forecasts of theses thresholds. However, the quality of the forecast of fine volcanic ash concentrations in the atmosphere depends to a great extent on a realistic description of the erupted mass flux of fine ash particles, which is rather uncertain. Numerous aerosol measurements (ground based and satellite remote sensing, and in situ measurements) all over Europe have tracked the volcanic ash clouds during the eruption of Eyjafjallajoekull offering the possibility for an interdisciplinary effort between volcanologists and aerosol researchers to analyse the release and dispersion of fine volcanic ash in order to better understand the needs for realistic volcanic ash forecasts. This contribution describes the uncertainties related to the amount of fine volcanic ash released from Eyjafjallajoekull and its influence on the dispersion of volcanic ash over Europe by numerical modeling. We use the three-dimensional Eulerian atmosphere-chemistry/aerosol model REMOTE (Langmann et al., 2008) to simulate the distribution of volcanic ash as well as its deposition after the eruptions of Eyjafjallajoekull during April and May 2010. The model has been used before to simulate the fate of the volcanic ash after the volcanic eruptions of Kasatochi in 2008 (Langmann et al., 2010) and Mt. Pinatubo in 1991. Comparing our model results with available measurements for the Eyjafjallajoekull eruption we find a quite good agreement with available ash concentrations data measured over Europe as well as with the results from other models. Langmann, B., K. Zakšek and M. Hort, Atmospheric distribution and removal of volcanic ash after the eruption of Kasatochi volcano

  20. The Treatment of Central Sleep Apnea Syndromes in Adults: Practice Parameters with an Evidence-Based Literature Review and Meta-Analyses

    PubMed Central

    Aurora, R. Nisha; Chowdhuri, Susmita; Ramar, Kannan; Bista, Sabin R.; Casey, Kenneth R.; Lamm, Carin I.; Kristo, David A.; Mallea, Jorge M.; Rowley, James A.; Zak, Rochelle S.; Tracy, Sharon L.

    2012-01-01

    CSAS. (OPTION)The use of zolpidem and triazolam may be considered for the treatment of primary CSAS only if the patient does not have underlying risk factors for respiratory depression. (OPTION)The following possible treatment options for CSAS related to end-stage renal disease may be considered: CPAP, supplemental oxygen, bicarbonate buffer use during dialysis, and nocturnal dialysis. (OPTION) Citation: Aurora RN; Chowdhuri S; Ramar K; Bista SR; Casey KR; Lamm CI; Kristo DA; Mallea JM; Rowley JA; Zak RS; Tracy SL. The treatment of central sleep apnea syndromes in adults: practice parameters with an evidence-based literature review and meta-analyses. SLEEP 2012;35(1):17-40. PMID:22215916

  1. Rapid-Adiabatic Control of Ro-Vibrational Populations in Polyatomic Molecules

    NASA Astrophysics Data System (ADS)

    Zak, Emil J.; Yachmenev, Andrey

    2017-06-01

    We present a simple method for control of ro-vibrational populations in polyatomic molecules in the presence of inhomogeneous electric fields [1]. Cooling and trapping of heavy polar polyatomic molecules has become one of the frontier goals in high-resolution molecular spectroscopy, especially in the context of parity violation measurement in chiral compounds [2]. A key step toward reaching this goal would be development of a robust and efficient protocol for control of populations of ro-vibrational states in polyatomic, often floppy molecules. Here we demonstrate a modification of the stark-chirped rapid-adiabatic-passage technique (SCRAP) [3], designed for achieving high levels of control of ro-vibrational populations over a selected region in space. The new method employs inhomogeneous electric fields to generate space- and time- controlled Stark-shifts of energy levels in molecules. Adiabatic passage between ro-vibrational states is enabled by the pump pulse, which raises the value of the Rabi frequency. This Stark-chirped population transfer can be used in manipulation of population differences between high-field-seeking and low-field-seeking states of molecules in the Stark decelerator [4]. Appropriate timing of voltages on electric rods located along the decelerator combined with a single pump laser renders our method as potentially more efficient than traditional Stark decelerator techniques. Simulations for NH_3 show significant improvement in effectiveness of cooling, with respect to the standard 'moving-potential' method [5]. At the same time a high phase-space acceptance of the molecular packet is maintained. E. J. Zak, A. Yachmenev (submitted). C. Medcraft, R. Wolf, M. Schnell, Angew. Chem. Int. Ed., 53, 43, 11656-11659 (2014) M. Oberst, H. Munch, T. Halfman, PRL 99, 173001 (2007). K. Wohlfart, F. Grätz, F. Filsinger, H. Haak, G. Meijer, J. Küpper, Phys. Rev. A 77, 031404(R) (2008). H. L. Bethlem, F. M. H. Crompvoets, R. T. Jongma, S. Y. T. van de

  2. Cytokine Polymorphisms are Associated with Poor Sleep Maintenance in Adults Living with Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome

    PubMed Central

    Lee, Kathryn A.; Gay, Caryl; Pullinger, Clive R.; Hennessy, Mary Dawn; Zak, Rochelle S.; Aouizerat, Bradley E.

    2014-01-01

    Study Objectives: Cytokine activity and polymorphisms have been associated with sleep outcomes in prior animal and human research. The purpose of this study was to determine whether circulating plasma cytokines and cytokine polymorphisms are associated with the poor sleep maintenance commonly experienced by adults living with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). Design: Cross-sectional descriptive study. Setting: HIV clinics and community sites in the San Francisco Bay area. Participants: A convenience sample of 289 adults (193 men, 73 women, and 23 transgender) living with HIV/AIDS. Interventions: None. Measurements and Results: A wrist actigraph was worn for 72 h to estimate the percentage of wake after sleep onset (WASO%) and total sleep time (TST), plasma cytokines were analyzed, and genotyping was conducted for 15 candidate genes involved in cytokine signaling: interferon-gamma (IFNG), IFNG receptor 1 (IFNGR1), interleukins (IL1B, IL1R2, IL1R2, IL2, IL4, IL6, IL8, IL10, IL13, IL17A), nuclear factor of kappa light polypeptide gene enhancer in B cells (NFKB1 and NFKB2), and tumor necrosis factor-alpha (TNFA). Controlling for demographic variables such as race and sex, and clinical variables such as CD4+ count and medications, higher WASO% was associated with single nucleotide polymorphisms (SNPs) of IL1R2 rs11674595 and TNFA rs1041981 and less WASO% was associated with IL2 rs2069776. IL1R2 rs11674595 and TNFA rs1041981 were also associated with short sleep duration. Conclusions: This study strengthens the evidence for an association between inflammation and sleep maintenance problems. In this chronic illness population, cytokine polymorphisms associated with wake after sleep onset provide direction for intervention research aimed at comparing anti-inflammatory mechanisms with hypnotic agents for improving sleep maintenance and total sleep time. Citation: Lee KA; Gay C; Pullinger CR; Hennessy MD; Zak RS; Aouizerat BE

  3. Underground Lead-Zinc Mine Production Planning Using Fuzzy Stochastic Inventory Policy / Planowanie Wydobycia Cynku I Ołowiu W Kopalniach Podziemnych Z Wykorzystaniem Podejścia Stochastycznego Z Elementami Logiki Rozmytej Do Określania Niezbędnego Poziomu Zapasów

    NASA Astrophysics Data System (ADS)

    Gligoric, Zoran; Beljic, Cedomir; Gluscevic, Branko; Cvijovic, Cedomir

    2015-03-01

    Methodology for long-term underground lead-zinc mine planning based on fuzzy inventory theory is presented in this paper. We developed a fuzzy stochastic model of inventory control problem for planning lead-zinc ore production under uncertainty. The final purpose of this article is to find the optimal quantity of mined ore that should be stockpiled, in order to enable "feeding" of mineral processing plant in cases when the production in underground mine is interrupted, by using Possibilistic mean value of fuzzy number for defuzzing the fuzzy total annual inventory costs, and by using Extension of the Lagrangean method for solving inequality constrain problem. The different types of costs involved in mined ore inventory problems affect the efficiency of production scheduling. Dynamic nature of lead and zinc metal price is described by Ornstein-Uhlenbeck stochastic mean reverting process. The model is illustrated with a numerical example. W pracy przedstawiono metodologię długoterminowego wydobycia cynku i ołowiu w kopalniach podziemnych z wykorzystaniem podejścia stochastycznego z elementami logiki rozmytej do określania wymaganego poziomu zapasów. Opracowaliśmy model stochastyczny z wykorzystaniem elementów logiki rozmytej do kontroli zapasów w planowaniu wydobycia cynku i ołowiu w warunkach niepewności. Celem końcowym pracy jest określenie optymalnej ilości wydobywanej rudy, którą należy zachować jako zapas tak aby zapewnić odpowiednie jej dostawy do zakładu przeróbczego nawet w przypadku przerwania wydobycia w kopalni podziemnej, opierając się na posybilistycznej wartości średniej liczby rozmytej i wyostrzeniu całkowitych rocznych kosztów zapasów. Wykorzystano także rozszerzenie metody Lagrange'a do rozwiązywania problemu więzów w nierówności. Różnorakie koszty związane ze składowaniem zapasów wydobywanej rudy mają wpływ na wydajność planowanej produkcji. Dynamiczne zmiany cen cynku i o

  4. [Evaluation of using statistical methods in selected national medical journals].

    PubMed

    Sych, Z

    1996-01-01

    The paper covers the performed evaluation of frequency with which the statistical methods were applied in analyzed works having been published in six selected, national medical journals in the years 1988-1992. For analysis the following journals were chosen, namely: Klinika Oczna, Medycyna Pracy, Pediatria Polska, Polski Tygodnik Lekarski, Roczniki Państwowego Zakładu Higieny, Zdrowie Publiczne. Appropriate number of works up to the average in the remaining medical journals was randomly selected from respective volumes of Pol. Tyg. Lek. The studies did not include works wherein the statistical analysis was not implemented, which referred both to national and international publications. That exemption was also extended to review papers, casuistic ones, reviews of books, handbooks, monographies, reports from scientific congresses, as well as papers on historical topics. The number of works was defined in each volume. Next, analysis was performed to establish the mode of finding out a suitable sample in respective studies, differentiating two categories: random and target selections. Attention was also paid to the presence of control sample in the individual works. In the analysis attention was also focussed on the existence of sample characteristics, setting up three categories: complete, partial and lacking. In evaluating the analyzed works an effort was made to present the results of studies in tables and figures (Tab. 1, 3). Analysis was accomplished with regard to the rate of employing statistical methods in analyzed works in relevant volumes of six selected, national medical journals for the years 1988-1992, simultaneously determining the number of works, in which no statistical methods were used. Concurrently the frequency of applying the individual statistical methods was analyzed in the scrutinized works. Prominence was given to fundamental statistical methods in the field of descriptive statistics (measures of position, measures of dispersion) as well as

  5. Safe Vibrations of Spilling Basin Explosions at "Gotvand Olya Dam" Using Artificial Neural Network

    NASA Astrophysics Data System (ADS)

    Bakhshandeh Amnieh, Hassan; Bahadori, Moein

    2014-12-01

    ów zarejestrowane przy użyciu sejsmografu 3 VIBROLOC. Maksymalna i minimalna odległość pomiędzy środkiem rozkruszanego bloku a stacją rejestrującą ustawiona została na poziomie 244 i 11 m. W celu określenia bezpiecznego poziomu drgań oraz dopuszczalnej wagi ładunku, zastosowano podejście wykorzystujące sieci neuronowe, z wykorzystaniem metody propagacji wstecznej i trzech warstw ukrytych. Błąd średniokwadratowy i współczynnik korelacji sieci wyniosły 1.95 i 0.95, co pozostaje w zgodności z danym uzyskiwanymi z obserwacji empirycznych, wskazując na poprawność i dokładność prognoz. Zakładając wysoki poziom dokładności sieci oraz wysoką dokładność w prognozowaniu poziomu drgań wywołanych przez prace strzałowe, przyjęto że najbliższa odległość od środka rozkruszanego bloku wyniesie 11 m. Uwzględniając standardowe dopuszczalne w przypadku ciężkich budowli betonowych poziomy drgań w wysokości 120 m/s, oszacowano że maksymalna dopuszczalna masa ładunku wyniesie 47.00 Kg, w przeliczeniu na jeden okres zwłoki. Wyniki badań wykorzystane być mogą w planowaniu kolejnych bezpiecznych prac strzałowych.

  6. Exupéry - a mobile fast response system for managing a volcanic crisis

    NASA Astrophysics Data System (ADS)

    Hort, M. K.

    2009-12-01

    analyze the incoming data (e.g. earthquake classification, rapid moment tensor inversion, deformation modeling, an automatic alert level system) which are currently under development. Exupery Working Group: Barsch R (2); Bernsdorf S (3); Beyreuther M (2); Cong X (4); Dahm T (1); Eineder M (4); Erbertseder T (4); Gerstenecker C (5); Hammer C (6); Hansteen T (7); Krieger L (1); Läufer G (5); Maerker C (4); Montalvo Garcia A (1); Ohrnberger M (6); Rix M (4); Rödelsperger S (5); Seidenberger K (4); Shirzaei M (8); Stammler K (9); Stittgen H (9); Valks P (4); Walter T (8); Wallenstein N (10); Wassermann J (2); Zakšek K (1) (1)Institute of Geophysics, Hamburg, Germany; (2) Department of Earth and Environmental Sciences, Geophysical Observatory, Munich, Germany; (3)Centauron - geosoftware & consulting, Weimar, Germany; (4)DLR Oberpfaffenhofen, Germany; (5)Institute of Physical Geodesy, Darmstadt, Germany; (6)Institute of Geosciences, Potsdam, Germany; (7) IFM-GEOMAR, Leibniz Institute of Marine Sciences, Germany; (8)Department physics of the earth, GFZ, Potsdam, Germany; (9)BGR, Geocentre Hannover, Germany; (10)CVARG, Universidade Dos Acores; Portugal

  7. Isotope characterisation of historical alabaster quarries in Western Europe.

    NASA Astrophysics Data System (ADS)

    Kloppmann, Wolfram; Leroux, Lise; Bromblet, Philippe; Cooper, Anthony H.; Nestler, Angela; Guerrot, Catherine; Montech, Anne-Thérèse; Worley, Noel

    2015-04-01

    ranging from the 14th to 16th century from the Louvre Museum, Cleveland Museum of Fine Arts, the Petit Palais Museum in Avignon and several regional collections and monuments. Burke W. H., Denison R. E., Hetherington E. A., Koepnick R. B., Nelson H. F., and Otto J. B. (1982) Variation of seawater 87Sr/86Sr throughout Phanerozoic time. Geology 10, 516-519. Claypool G. E., Holser W. T., Kaplan I. R., Sakai H., and Zak I. (1980) The age curves of sulfur and oxygen isotopes in marine sulfate and their mutual interpretation. Chem. Geol. 28, 199-260. Denison R. E., Kirkland D. W., and Evans R. (1998) Using strontium isotopes to determine the age and origin of gypsum and anhydrite beds. J. Geol. 106, 1-17. Kloppmann W., Leroux L., Bromblet P., Guerrot C., Proust E., Cooper A. H., Worley N., Smeds S. A., and Bengtsson H. (2014) Tracing Medieval and Renaissance Alabaster Works of Art Back to Quarries: A Multi-Isotope (Sr, S, O) Approach. Archaeometry 56, 203-219.

  8. Soil Aeration deficiencies in urban sites

    NASA Astrophysics Data System (ADS)

    Weltecke, Katharina; Gaertig, Thorsten

    2010-05-01

    root density and tree vigour on urban soils. For that purpose gas diffusivity, soil CO2 concentrations and fine root density were measured on typical urban sites in the German cities of Göttingen, Mannheim, and Kassel. The known characteristics of soil aeration on forest sites could be affirmed for urban soils. A negative correlation was found between gas diffusion coefficients and CO2 concentration as well as between fine root extension and CO2 concentration. Changes in crown structure of beech indicating a loss of vigour were found at sites with disturbed aeration. Diffusivity patterns and CO2 concentrations of different specific urban soil sealing types were found. On more natural sites (mulch, grass) increased gas diffusion and low CO2 concentration were present. In contrast, on more compacted or sealed areas (asphalt, paving stone, macadamised road surface) the exchange between soil air and atmosphere was nearly disconnected and soil CO2 concentrations partly exceeded the known critical value of 0.6 % up to tenfold. Literature Burton, A. J.; Pregitzer, K. S.; Zogg, G. P. und Zak D. R. (1997): Effect of measurement CO2 concentrations on sugar maple root respiration. In: Canadian journal of Forest Research, H. 17, S. 421-427. Gaertig, T. (2001): Bodengashaushalt, Feinwurzeln und Vitalität von Eichen. In: Freiburger Bodenkundliche Abhandlungen, H. 40, S. 157. Qi, J.; Marshall, J. D.; Mattson, K. G. (1994): High soil carbon dioxide concentrations inhibit root respiration of Douglas fir. In: New Phytol., Jg. 128, H. 3, S. 435-442. Schack-Kirchner, H.; Gaertig, T.; Wilpert, K. v.; Hildebrand, E. E. (2001): A modified McIntyre and Phillip approach to measure top-soil gas diffusivity in-situ. In: J. Plant Nutr. Soil Sci., Jg. 164, S. 253-258.

  9. Extending the Standard Model with Confining and Conformal Dynamics

    NASA Astrophysics Data System (ADS)

    McRaven, John Emory

    would leave very little of its energy in the calorimeter, so while detecting the presence of a heavy stable state would be easy, measuring the strength of the detecting it would require accurate measurements of missing energy, or the ability to identify it in the muon tracker. We then study the phenomenology of a 4D model of electroweak symmetry breaking through the condensation of magnetic monopoles. A new generation of fermions with magnetic charges in addition to electric charges is introduced. The dyons condense and break the electroweak symmetry. The magnetic coupling is inversely proportional to the electric coupling, causing it to be strong. The processes involving magnetic couplings thus provide interesting phenomenology to study. We primarily study the processes involving di-photon production and compare it to early LHC results. Finally, we calculate triangle anomalies for fermions with non-canonical scaling dimensions. The most well known example of such fermions (aka unfermions) occurs in Seiberg duality where the matching of anomalies (including mesinos with scaling dimensions between 3/2 and 5/2) is a crucial test of duality. By weakly gauging the non-local action for an unfermion, we calculate the one-loop three-current amplitude. Despite the fact that there are more graphs with more complicated propagators and vertices, we find that the calculation can be completed in a way that nearly parallels the usual case. We show that the anomaly factor for fermionic unparticles is independent of the scaling dimension and identical to that for ordinary fermions. This can be viewed as a confirmation that unparticle actions correctly capture the physics of conformal fixed point theories like Banks-Zaks or SUSY QCD.

  10. Practice Parameters for the Clinical Evaluation and Treatment of Circadian Rhythm Sleep Disorders

    PubMed Central

    Morgenthaler, Timothy I.; Lee-Chiong, Teofilo; Alessi, Cathy; Friedman, Leah; Aurora, R. Nisha; Boehlecke, Brian; Brown, Terry; Chesson, Andrew L.; Kapur, Vishesh; Maganti, Rama; Owens, Judith; Pancer, Jeffrey; Swick, Todd J.; Zak, Rochelle

    2007-01-01

    the diagnosis of FRD in sighted and unsighted patients but there is insufficient evidence to recommend their routine use in the diagnosis of SWD, JLD, ASPD, DSPD, or ISWR (Option). Additionally, actigraphy is useful as an outcome measure in evaluating the response to treatment for CRSDs (Guideline). A range of therapeutic interventions were considered including planned sleep schedules, timed light exposure, timed melatonin doses, hypnotics, stimulants, and alerting agents. Planned or prescribed sleep schedules are indicated in SWD (Standard) and in JLD, DSPD, ASPD, ISWR (excluding elderly-demented/nursing home residents), and FRD (Option). Specifically dosed and timed light exposure is indicated for each of the circadian disorders with variable success (Option). Timed melatonin administration is indicated for JLD (Standard); SWD, DSPD, and FRD in unsighted persons (Guideline); and for ASPD, FRD in sighted individuals, and for ISWR in children with moderate to severe psychomotor retardation (Option). Hypnotic medications may be indicated to promote or improve daytime sleep among night shift workers (Guideline) and to treat jet lag-induced insomnia (Option). Stimulants may be indicated to improve alertness in JLD and SWD (Option) but may have risks that must be weighed prior to use. Modafinil may be indicated to improve alertness during the night shift for patients with SWD (Guideline). Citation: Morgenthaler TI; Lee-Chiong T; Alessi C; Friedman L; Aurora N; Boehlecke B; Brown T; Chesson AL; Kapur V; Maganti R; Owens J; Pancer J; Swick TJ; Zak R; Standards of Practice Committee of the AASM. Practice Parameters for the Clinical Evaluation and Treatment of Circadian Rhythm Sleep Disorders. SLEEP 2007;30(11):1445-1459. PMID:18041479

  11. Practice Parameters for the Use of Autotitrating Continuous Positive Airway Pressure Devices for Titrating Pressures and Treating Adult Patients with Obstructive Sleep Apnea Syndrome: An Update for 2007

    PubMed Central

    Morgenthaler, Timothy I.; Aurora, R. Nisha; Brown, Terry; Zak, Rochelle; Alessi, Cathy; Boehlecke, Brian; Chesson, Andrew L.; Friedman, Leah; Kapur, Vishesh; Maganti, Rama; Owens, Judith; Pancer, Jeffrey; Swick, Todd J.

    2008-01-01

    significant comorbidities (CHF, COPD, central sleep apnea syndromes, or hypoventilation syndromes); (6) certain APAP devices may be used in an unattended way to determine a fixed CPAP treatment pressure for patients with moderate to severe OSA without significant comorbidities (CHF, COPD, central sleep apnea syndromes, or hypoventilation syndromes); (7) patients being treated with fixed CPAP on the basis of APAP titration or being treated with APAP must have close clinical follow-up to determine treatment effectiveness and safety; and (8) a reevaluation and, if necessary, a standard attended CPAP titration should be performed if symptoms do not resolve or the APAP treatment otherwise appears to lack efficacy. Citation: Morgenthaler TI; Aurora RN; Brown T; Zak R; Alessi C; Boehlecke B; Chesson AL; Friedman L; Kapur V; Maganti R; Owens J; Pancer J; Swick TJ; Standards of Practice Committee of the AASM. Practice parameters for the use of autotitrating continuous positive airway pressure devices for titrating pressures and treating adult patients with obstructive sleep apnea syndrome: An update for 2007. SLEEP 2008;31(1):141-147. PMID:18220088

  12. Cosmic Lens Reveals Distant Galactic Violence

    NASA Astrophysics Data System (ADS)

    2008-10-01

    By cleverly unraveling the workings of a natural cosmic lens, astronomers have gained a rare glimpse of the violent assembly of a young galaxy in the early Universe. Their new picture suggests that the galaxy has collided with another, feeding a supermassive black hole and triggering a tremendous burst of star formation. Gravitational Lens Diagram Imaging a Distant Galaxy Using a Gravitational Lens CREDIT: Bill Saxton, NRAO/AUI/NSF Click on image for details and more graphics. The astronomers used the National Science Foundation's Very Large Array (VLA) radio telescope to look at a galaxy more than 12 billion light-years from Earth, seen as it was when the Universe was only about 15 percent of its current age. Between this galaxy and Earth lies another distant galaxy, so perfectly aligned along the line of sight that its gravity bends the light and radio waves from the farther object into a circle, or "Einstein Ring." This gravitational lens made it possible for the scientists to learn details of the young, distant galaxy that would have been unobtainable otherwise. "Nature provided us with a magnifying glass to peer into the workings of a nascent galaxy, providing an exciting look at the violent, messy process of building galaxies in the early history of the Universe," said Dominik Riechers, who led this project at the Max Planck Institute for Astronomy in Germany and now is a Hubble Fellow at the California Institute of Technology (Caltech). The new picture of the distant galaxy, dubbed PSS J2322+1944, shows a massive reservoir of gas, 16,000 light-years in diameter, that contains the raw material for building new stars. A supermassive black hole is voraciously eating material, and new stars are being born at the rate of nearly 700 Suns per year. By comparison, our Milky Way Galaxy produces the equivalent of about 3-4 Suns per year. The black hole appears to be near the edge, rather than at the center, of the giant gas reservoir, indicating, the astronomers say

  13. Coming Home at Paranal

    NASA Astrophysics Data System (ADS)

    2002-02-01

    , won by Auer and Weber Freie Architekten from Munich (Germany), and with Dominik Schenkirz as principal designer. The interior furnishing and decoration was awarded to the Chilean architect Paula Gutierrez . The construction began in late 1998. Information about this work and several photos illustrating the progress have been published as PR Photos 31a-d/99 , PR Photo 43h/99 and PR Photos 04b-d/01 . Taking advantage of an existing depression in the ground, the architects created a unique subterranean construction with a single facade opening towards the Pacific Ocean , far below at a distance of about 12 km. It has the same colour as the desert and blends perfectly into the surroundings. The Paranal Residencia is elegant, with robust and inexpensive materials. Natural daylight is brought into the building through a 35-m wide glass-covered dome, a rectangular courtyard roof and various skylight hatches. The great originality of this design has made it possible to create an interior with a feeling of open space, despite the underground location. Some building characteristics are indicated below Facilities at the Residencia To the visitor who arrives at the Paranal Residencia from the harsh natural environment, the welcoming feeling under the dome is unexpected and instantly pleasant. This is a true "oasis" within coloured concrete walls and the air is agreeably warm and moist. There is a strong sense of calm and serenity and, above all, a feeling of coming home . At night, the lighting below the roofing closure fabric is spectacular and the impression on the mind is overwhelming. The various facilities are integrated over four floors below ground level. They include small, but nice and simple bedrooms, offices, meeting points, a restaurant, a library, a reception area, a cinema and other recreational areas. The natural focal point is located next to the reception at the entrance. The dining room articulates the building at the -2 level and view points through the facade

  14. The Application of Modern Techniques and Measurement Devices for Identification of Copper Ore Types and Their Properties / Wykorzystanie nowoczesnych technik i urządzeń pomiarowych do identyfikacji typów rud miedzi i ich właściwości

    NASA Astrophysics Data System (ADS)

    Krawczykowska, Aldona; Trybalski, Kazimierz; Krawczykowski, Damian

    2013-06-01

    The paper concerns the application of modern methods and research techniques for investigations of copper ore properties. It presents the procedure and tools which, when put together, can constitute a source of information on properties of different products of processing and, simultaneously, can be used in the process control and optimization. The copper ore of one of the branches of the KHGM Polska Miedz plc was investigated. The ore samples represented each of the three lithological types occurring in the Polish deposits, i.e. carbonate, shale and sandstone ores. The paper presents the results of microscopic analyses, image analysis of scanning photographs and application procedures of the obtained information for the identification of ore types (application of neuron networks to the recognition of lithological compositions). The present publication will present sample results of modelling of classification identifying two types of ores, i.e. carbonate-shale and sandstone. Summing up the predictions of ore type fractions in respective mixtures for the considered problem of classification it can be stated that the prediction results are good and confirm the lithological predominance of certain ore types in the investigated mixtures. The experimental part comprised the determination of mineralogical and lithological composition of ores (optical microscope) and also elemental composition in the microareas of analysed samples (scanning microscope). Next, the image analysis was performed and subsequently the models classifying the ore types were made. W rudzie miedzi przerabianej w zakładach wzbogacania O/ZWR KGHM Polska Miedź S.A. można wyróżnić trzy typy litologiczne: rudę węglanową, łupkową i piaskowcową. Typy te różnią się właściwościami między innymi takimi jak: rodzaj i zawartość minerałów miedzi, rodzaj minerałów nieużytecznych, zawartość miedzi, twardość i podatność na rozdrabnianie, ale także wielkością i kształtem ziaren

  15. Practice Parameters for the Respiratory Indications for Polysomnography in Children

    PubMed Central

    Aurora, R. Nisha; Zak, Rochelle S.; Karippot, Anoop; Lamm, Carin I.; Morgenthaler, Timothy I.; Auerbach, Sanford H.; Bista, Sabin R.; Casey, Kenneth R.; Chowdhuri, Susmita; Kristo, David A.; Ramar, Kannan

    2011-01-01

    sleep apnea syndrome in children. (Option) 17. Children considered for treatment with supplemental oxygen do not routinely require polysomnography for management of oxygen therapy. (Option) Conclusions: Current evidence in the field of pediatric sleep medicine indicates that PSG has clinical utility in the diagnosis and management of sleep related breathing disorders. The accurate diagnosis of SRBD in the pediatric population is best accomplished by integration of polysomnographic findings with clinical evaluation. Citation: Aurora RN; Zak RS; Karippot A; Lamm CI; Morgenthaler TI; Auerbach SH; Bista SR; Casey KR; Chowdhuri S; Kristo DA; Ramar K. Practice parameters for the respiratory indications for polysomnography in children. SLEEP 2011;34(3):379-388. PMID:21359087

  16. Trading forests for yields in the Peruvian Amazon

    NASA Astrophysics Data System (ADS)

    Gibbs, Holly

    2012-03-01

    inhabited and often have contested land tenure. We must carefully consider our consumption of these commodities in the face of growing land scarcity (Lambin and Meyfroidt 2011). If high-yield plantations displace low-yield plantations they too may follow the path of industrial agriculture and resume destruction of the forests that conservation efforts aim to protect. Without clear incentives to spare land, we could be trading forest for higher yields. References Angelsen A and Kaimowitz D 2001 Agricultural Technologies and Tropical Deforestation (New York: CABI Publishing) (www.cifor.org/publications/pdf files/books/bangelsen0101e0.pdf) Butler R and Laurance W 2010 Is oil palm the next emerging threat to the Amazon? Trop. Conserv. Sci. 2 1-10 Gibbs H K, Johnston M, Foley J A, Holloway T, Monfreda C, Ramankutty N and Zaks D 2008 Carbon payback times for crop-based biofuel expansion in the tropics: the effects of changing yield and technology Environ. Res. Lett. 3 034001 Gibbs H K, Ruesch A S, Achard F, Clayton M K, Holmgren P, Ramankutty N and Foley J A 2010 Tropical forests were the primary sources of new agricultural land in the 1980s and 1990s Proc. Natl Acad. Sci. 107 16732-7 Gutiérrez-Vélez V H, DeFries R, Pinedo-Vásquez M, Uriarte M, Padoch C, Baethgen W, Fernandes K and Lim Y 2011 High-yield oil palm expansion spares land at the expense of forests in the Peruvian Amazon Environ. Res. Lett. 6 044029 Koh L and Wilcove D 2008 Is oil palm agriculture really destroying tropical biodiversity? Conserv. Lett. 1 60-4 Lambin E and Meyfroidt P 2011 Inaugural article: global land use change, economic globalization, and the looming land scarcity Proc. Natl Acad. Sci. 108 93465-72 Morton D C et al 2006 Cropland expansion changes deforestation dynamics in the southern Brazilian Amazon Proc. Natl Acad. Sci. USA 103 14637-41

  17. Methodology of Calculation the Terminal Settling Velocity Distribution of Spherical Particles for High Values of the Reynold's Number

    NASA Astrophysics Data System (ADS)

    Surowiak, Agnieszka; Brożek, Marian

    2014-03-01

    e jest funkcją dwóch cech prostych, którymi są: wielkość ziarna i gęstość ziarna. Przynależność do określonego podzbioru ziaren jest określona przez wartość dwóch cech, a rozkład tych cech w próbce jest funkcją rozkładów gęstości i wielkości ziarna. Znajomość rozkładu prędkości opadania ziaren w osadzarce jest istotnym parametrem jak znajomość rozkładu wielkości ziarna w procesie przesiewania czy znajomość rozkładu gęstości w procesie wzbogacania w cieczach ciężkich. W artykule przedstawiono metodykę wyliczania rozkładu prędkości opadania ziaren sferycznych w warunkach ruchu turbulentnego wyrażonego przy pomocy równania Newtona. Zarówno gęstość jak i wielkość ziarna są zmiennymi losowymi o określonych rozkładach. W związku z tym prędkość opadania ziarna jako funkcja cech prostych tj. gęstości i wielkości ziarna będzie również zmienną losową o rozkładzie, który jest funkcją rozkładów argumentów prostych. Wykorzystując twierdzenia rachunku prawdopodobieństwa odnoszące się do rozkładów funkcji zmiennych losowych przedstawiono ogólny wzór na funkcję gęstości rozkładu prędkości opadania w warunkach ruchu turbulentnego. Empiryczne rozkłady wielkości i gęstości ziaren aproksymowano rozkładem Weibulla. Rozkład prędkości opadania wyliczono numerycznie i przedstawiono w postaci graficznej. W artykule przedstawiono symulację wyliczania rozkładu prędkości opadania w oparciu o rzeczywiste rozkłady gęstości i średnicy projekcyjnej ziaren zakładając, że ziarna mają kształt sferyczny.

  18. Determination of Critical Conditions of Spontaneous Combustion of Coal in Longwall Gob Areas / Wyznaczanie Warunków Krytycznych Samozapalania Węgla W Zrobach Ścian

    NASA Astrophysics Data System (ADS)

    Cygankiewicz, Janusz

    2015-09-01

    pożaru niektórych warunków panujących w danym miejscu kopalni, takich jak: - skłonność węgla do samozapalania - zawartość tlenu w powietrzu dopływającym do zagrzewającego się węgla. W pracy przedstawiono numeryczną metodę wyznaczania warunków krytycznych samozapalania węgla w zrobach ścian, czyli takich po spełnieniu których może dojść do samozapalenia. Przyjęto, że znajdujący się w zrobach rozkruszony węgiel ma kształt płaskiej warstwy, sąsiadującej od stropu i spągu ze skałami. Rozważania ograniczono do węgli charakteryzujących się niską zawartością wilgoci. Przyjęto prosty model kinetyki utleniania na powierzchni węgla wyrażony równaniem Arrheniusa. Model ten zakłada niezależność szybkości utleniania od ilości tlenu pochłoniętego przez węgiel. Szybkość reakcji zależy jedynie od temperatury , przy czym występujące w równaniu parametry zmieniają się po osiągnięciu przez węgiel temperatury krytycznej. W artykule przedstawiono matematyczny model samozagrzewania warstwy węgla w zrobach opisujący bilans ciepła w węglu oraz bilans tlenu i bilans ciepła w przepływających gazach. Tworzące model układy równań różniczkowych cząstkowych rozwiązywane są metodami numerycznymi. Opracowany program komputerowy umożliwia wykonywanie stosownych obliczeń. W pracy, na przykładzie węgla z pokładu 405 , przedstawiono sposób wyznaczania warunków krytycznych warstwy rozkruszonego węgla: grubości warstwy, zawartości tlenu w przepływających przez warstwę gazach oraz przewodności cieplnej otaczających skał.

  19. Modelling of Underground Coal Gasification Process Using CFD Methods / Modelowanie Procesu Podziemnego Zgazowania Węgla Kamiennego Z Zastosowaniem Metod CFD

    NASA Astrophysics Data System (ADS)

    Wachowicz, Jan; Łączny, Jacek Marian; Iwaszenko, Sebastian; Janoszek, Tomasz; Cempa-Balewicz, Magdalena

    2015-09-01

    ł transportu energii cieplnej. Warstwę węgla oraz warstwy geologiczne otaczające georeaktor traktuje się jako ciało jednorodne. Badania modelowe zakładały prowadzenie procesu zgazowania calizny węglowej przy udziale, osobno tlenu i powietrza, jako czynnika zgazowującego, w warunkach ustalonych pracy georeaktora w przedziale czasu 100 godzin i 305 godzin. Uzyskane wyniki rozwiązania numerycznego zestawiono z wynikami badań eksperymentalnych w warunkach in-situ.

  20. New gravity control in Poland - needs, the concept and the design

    NASA Astrophysics Data System (ADS)

    Krynski, Jan; Olszak, Tomasz; Barlik, Marcin; Dykowski, Przemyslaw

    2013-06-01

    transformation to a new system (as 2nd order network) as well as a definition of gravity system as "zero-tide" system. Seasonal variability of gravity has been discussed indicating that the effects of environmental changes when establishing modern gravity control with absolute gravity survey cannot be totally neglected. Założona w Polsce w ostatniej dekadzie XX wieku zgodnie z obowiązującymi standardami międzynarodowymi Podstawowa Osnowa Grawimetryczna Kraju (POGK), składająca się z około 350 punktów, została oparta na 12 absolutnych punktach grawimetrycznych, na których przyspieszenie siły ciężkości wyznaczono przy użyciu czterech różnych typów grawimetrów absolutnych. Względne pomiary grawimetryczne na punktach tej osnowy, z jednoczesnym dowiązaniem jej do przyspieszenia siły ciężkości na 12 absolutnych punktach grawimetrycznych, wykonały różne grupy pomiarowe przy wykorzystaniu grawimetrów LaCoste&Romberg (LCR). Konstrukcja powstałej sieci grawimetrycznej, w szczególności ograniczona liczba nierównomiernie rozłożonych punktów absolutnych na terenie kraju, na których w dodatku przyspieszenie siły ciężkości wyznaczono różnymi instrumentami w różnych epokach, spowodowały wystąpienie błędów systematycznych w wartościach g na punktach POGK. W niniejszej pracy, przy wykorzystaniu pomiarów grawimetrycznych wykonanych w latach 2007-2008 dokonano oceny tych błędów oraz przeprowadzono dyskusję ich możliwych źródeł. Rozwój technologii absolutnych pomiarów grawimetrycznych, w szczególności instrumentów przeznaczonych do precyzyjnych absolutnych pomiarów grawimetrycznych w warunkach polowych, stwarza możliwość założenia nowego typu osnowy grawimetrycznej, składającej się ze stacji, na których przyspieszenie siły ciężkości jest pomierzone grawimetrami absolutnymi. Nowa osnowa grawimetryczna Polski, która będzie zakładana w latach 2012-2014, będzie się składała z 28 punktów fundamentalnych (mierzonych

  1. Geotechnical Aspects of Revitalisation of Post-Mining Areas - An Example of the Adaptation of Katowice Hard Coal Mine for the New Silesian Museum / Geotechniczne aspekty rewitalizacji terenów pogórniczych - przykład adaptacji KWK "KATOWICE" na nowe muzeum śląskie

    NASA Astrophysics Data System (ADS)

    Cała, Marek; Ostręga, Anna

    2013-06-01

    The article presents the history of the Katowice Hard Coal Mine and the concept of revitalisation taking into consideration the historical development of the mine which today is closed. The concept accepted for realisation assumes adaptation of the post-mining area with its historical infrastructure for cultural functions, and namely for the construction of the New Silesian Museum. Basing the concept on the idea of minimum interference into the existing spatial layout of the former mine has had the result that the museum areas and garages have been designed under the surface of the area adjacent to the historic facilities of the mine. In relation therewith, it was necessary to carry out the works aimed at reinforcing foundations of the historic buildings and protecting the geotechnical pit slopes. The article presents the technological solutions applied to protect the historic buildings, the lift tower, and the excavations for new facilities of the Silesian Museum. Attention was drawn to the instability of the subsoil and of the rock mass due to previous mining operations conducted in the area, the need to adapt the protection technology to the existing conditions as well as the need of constant monitoring of geotechnical works underway.> It is emphasised that the presented investment is part of an ongoing process aimed at preserving the industrial part of the material cultural heritage of Upper Silesia, for centuries connected with hard coal mining and as such it stands a chance to become a showcase not only for Katowice but for the entire region of Silesia. W artykule przedstawiono historię Kopalni Węgla Kamiennego "Katowice" oraz koncepcję rewitalizacji uwzględniającą historyczną zabudowę nieczynnej już dziś kopalni. Przyjęta do realizacji koncepcja zakłada przystosowanie pogórniczego terenu wraz z zabytkową infrastrukturą dla funkcji kulturowych, a mianowicie budowy Nowego Muzeum Śląskiego. Siedziba Nowego Muzeum Śląskiego lokalizowana jest w

  2. Waterproof Anti-Explosive Powders for Coal Mines

    NASA Astrophysics Data System (ADS)

    Buczek, Bronisław; Vogt, Elżbieta

    2014-03-01

    properties not only as a water resistant material but also from the cohesion point of view. On the base of TG, DTG or DTA and EGA curves for all investigated materials was stated that the character of the thermal decomposition of modified samples is the same as this one for raw powder, what is profitable for application of hydrophobized powders as an anti-explosive agent. W górnictwie węgla kamiennego używany jest hydrofobowy pył wapienny jako substancja stosowana w systemie zabezpieczeń przeciwwybuchowych (Cybulski, 2004). Niestety, dotychczasowy sposób wy- twarzania takiego produktu polegający na współmieleniu kamienia wapiennego z kwasem stearynowym staje się praktycznie niemożliwy do stosowania w nowoczesnych zakładach np. kamieniołomy. Sytuacja taka jest wynikiem wprowadzania zmian technologicznych, głównie związanych z wymianą starych konstrukcji młynów na nowe urządzenia. Tym samym istnieje potrzeba poszukiwania nowych metod hydrofobizacji powierzchni pyłów wapiennych. W pracy omówiono dwie nowe metody hydrofobizacji pyłu wapiennego: za pomocą par kwasu stearynowego oraz roztworu silikonowego - Sarsil® H-15. Podczas badań używano surowego pyłu wapiennego pochodzącego z Kopalni Kamienia Wapiennego w Czatkowicach. Materiał ten jest dobrym materiałem do badań gdyż istnieje możliwość porównywania właściwości materiałów hydrofobowych otrzymanych w pracy z właściwościami handlowego pyłu przeciwwybuchowego (Polska Norma, 1994), używanego w polskich kopalniach. Pierwszy sposób hydrofobizacji pyłu wapiennego, polegający na swobodnym opadaniu pyłu wapiennego w oparach kwasu stearynowego przepływających w przeciwprądzie, przeprowadzono w aparacie własnej konstrukcji (Vogt, 2008, 2011). Aparat gwarantuje dobry kontakt modyfikatora z ziarnami pyłu. Pył opadając, nie napotyka żadnych przeszkód ulegał rozproszeniu, a wprowadzony w stanie parowym kwas stearynowy może swobodnie osiadać na jego powierzchni zewn

  3. Unique Project of Single-Cutting Head Longwall Shearer Used for Thin Coal Seams Exploitation / Projekt Jednoorganowego Kombajnu ŚCIANOWEGO O Specjalnej Konstrukcji Przeznaczonego do Eksploatacji POKŁADÓW Cienkich

    NASA Astrophysics Data System (ADS)

    Bołoz, Łukasz

    2013-12-01

    żowe zamiast płatów), aby powstający podczas frezowania urobek mógł spadać na spąg (Krauze, 2012b). Przykładowe rozwiązanie organu przestrzennego przedstawia fig. 3. Funkcję ładowania, realizowaną normalnie przez płaty, przejmują ładowarki. Rozdzielenie procesu ładowania od procesu frezowania jest jedną z najważniejszych zalet prezentowanego rozwiązania. Podczas pracy w ścianie parametry kinematyczne kombajnu mogą być zwiększane bez ryzyka wystąpienia problemów z ładowaniem na przenośnik, co obok możliwości ruchowych kombajnisty było głównym czynnikiem hamującym wzrost wydobycia. Załadunek urobku na przenośnik odbywa się za pomocą ładowarki, która po zmianie kierunku urabiania składa się, natomiast druga ustawiana jest w pozycji roboczej (Krauze, 2010). Kombajn porusza się tradycyjnie po rynnie przenośnika, jednak przy zastosowaniu cięgnowego systemu posuwu, który zrealizowany jest za pomocą napędów znajdujących się w chodnikach. Rozwiązanie takie umożliwia znaczne zmniejszenie gabarytów kombajnu dzięki usunięciu ciągników z kadłuba. Należy zaznaczyć, że w prezentowanym rozwiązaniu zakłada się zastosowanie pełnej automatyzacja pracy kombajnu i pozostałych maszyn ścianowych, co pozwala na urabianie calizny bez obecności załogi bezpośrednio w wyrobisku. Ma to duże znaczenie dla możliwości zwiększenia prędkości posuwu, szczególnie przy zakresie wysokości 1.0 m÷1.6 m. Przy wykorzystaniu znanych, z rozwiązań strugowych, systemów automatyki, sterowania i diagnostyki wprowadzenie automatyzacji procesu nie będzie stanowiło znaczącego problemu. W proponowanym rozwiązaniu kombajn ma możliwość wyjechania do chodnika na tyle, aby możliwe było zrealizowanie przekładki jak w przypadku strugów. Uzyskuje się wtedy krótki czas przekładki, który w skrajnym przypadku może zmieścić się w tzw. czasie organizacyjnym ściany. Ponadto urabianie odbywa się pełnym zabiorem na całej długości

  4. VLT Spectra "Resolve" a Stellar Disk at 25,000 Light-Years Distance

    NASA Astrophysics Data System (ADS)

    2001-04-01

    " ) that appeared in the April 1, 2001 issue of the "Astrophysical Journal" (available on the web at ApJL 550, L173 or astro-ph0011380). Notes [1] Note the recent ESO Press Release 06/01 about the VLT Interferometer. Observations of binary stars that undergo eclipses from time to time also allow indirect studies of the surfaces of the two components; such objects, however, influence each other and cannot be characterized as "normal" stars. [2] The team (the PLANET collaboration) consists of Michael Albrow , Kailash C. Sahu (Space Telescope Science Institute, Baltimore, MD, USA) Jin H. An (Dept. of Astronomy, Ohio State University, Columbus, OH, USA), Jean-Philippe Beaulieu (Institut d'Astrophysique de Paris, France), John A. R. Caldwell , John W. Menzies , Pierre Vermaak (South African Astronomical Observatory, Cape Town, South Africa), Martin Dominik , Penny D. Sackett (Kapteyn Astronomical Institute, Groningen, The Netherlands) , John Greenhill , Kym Hill , Stephen Kane , Robert Watson (University of Tasmania, Hobart, Tasmania, Australia), Ralph Martin , Andrew Williams (Perth Observatory, Australia), Karen Pollard (Physics Dept., Gettysburg College, PA, USA) and Peter H. Hauschildt (Dept. of Physics and Astronomy & Center for Simulational Physics, University of Georgia, Athens, GA, USA). [3] The distance to the Sun is 149.6 million kilometres; 25,000 light-years = 240,000,000,000,000,000 kilometres. 1 billion = 1000 million. [4] The diameter of the cool giant star is approx. 15 million km (about ten times that of the Sun). At the indicated distance, 25,000 light-years, this corresponds to a very small angle, about 10 micro-arcsec. This is equal to the angle subtended by a human hair (diameter 50 microns = 0.05 mm) at a distance of 1000 km. Technical information about the photos PR Photo 16b/01 shows a 0.25-sec acquisition exposure of EROS-BLG-2000-5 , obtained with VLT ANTU + FORS1 in order to set up the spectrograph slit for the subsequent spectral exposures. The