Analysis list: Bcl11a [Chip-atlas[Archive
Lifescience Database Archive (English)
Full Text Available Bcl11a Breast + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Bcl11a.1....tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Bcl11a.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Bcl1...1a.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Bcl11a.Breast.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Breast.gml ...
Directory of Open Access Journals (Sweden)
Sara B Estruch
Full Text Available Nuclear orphan receptor TLX (NR2E1 functions primarily as a transcriptional repressor and its pivotal role in brain development, glioblastoma, mental retardation and retinopathologies make it an attractive drug target. TLX is expressed in the neural stem cells (NSCs of the subventricular zone and the hippocampus subgranular zone, regions with persistent neurogenesis in the adult brain, and functions as an essential regulator of NSCs maintenance and self-renewal. Little is known about the TLX social network of interactors and only few TLX coregulators are described. To identify and characterize novel TLX-binders and possible coregulators, we performed yeast-two-hybrid (Y2H screens of a human adult brain cDNA library using different TLX constructs as baits. Our screens identified multiple clones of Atrophin-1 (ATN1, a previously described TLX interactor. In addition, we identified an interaction with the oncoprotein and zinc finger transcription factor BCL11A (CTIP1/Evi9, a key player in the hematopoietic system and in major blood-related malignancies. This interaction was validated by expression and coimmunoprecipitation in human cells. BCL11A potentiated the transrepressive function of TLX in an in vitro reporter gene assay. Our work suggests that BCL11A is a novel TLX coregulator that might be involved in TLX-dependent gene regulation in the brain.
Baines, John F; Parsch, John; Stephan, Wolfgang
2004-01-01
Recent advances in experimental analyses of the evolution of RNA secondary structures suggest a more complex scenario than that typically considered by Kimura's classical model of compensatory evolution. In this study, we examine one such case in more detail. Previous experimental analysis of long-range compensatory interactions between the two ends of Drosophila Adh mRNA failed to fit the classical model of compensatory evolution. To further investigate and verify long-range pairing in Drosophila Adh with respect to models of compensatory evolution and its potential functional role, we introduced site-directed mutations in the Drosophila melanogaster Adh gene. We explore two alternative hypotheses for why previous analysis of long-range compensatory interactions failed to fit the classical model. Specifically, we investigate whether the disruption of a conserved short-range pairing within Adh exon 2 has an effect on Adh expression or if there is a dual functional role of a conserved sequence in the 3'-UTR in both long-range pairing and the negative regulation of Adh expression. We find that a classical result was not observed due to the pleiotropic effect of changing a nucleotide involved in both long-range base pairing and the negative regulation of gene expression. PMID:15020421
Bcl11a (Ctip1) Controls Migration of Cortical Projection Neurons through Regulation of Sema3c.
Wiegreffe, Christoph; Simon, Ruth; Peschkes, Katharina; Kling, Carolin; Strehle, Michael; Cheng, Jin; Srivatsa, Swathi; Liu, Pentao; Jenkins, Nancy A; Copeland, Neal G; Tarabykin, Victor; Britsch, Stefan
2015-07-15
During neocortical development, neurons undergo polarization, oriented migration, and layer-type-specific differentiation. The transcriptional programs underlying these processes are not completely understood. Here, we show that the transcription factor Bcl11a regulates polarity and migration of upper layer neurons. Bcl11a-deficient late-born neurons fail to correctly switch from multipolar to bipolar morphology, resulting in impaired radial migration. We show that the expression of Sema3c is increased in migrating Bcl11a-deficient neurons and that Bcl11a is a direct negative regulator of Sema3c transcription. In vivo gain-of-function and rescue experiments demonstrate that Sema3c is a major downstream effector of Bcl11a required for the cell polarity switch and for the migration of upper layer neurons. Our data uncover a novel Bcl11a/Sema3c-dependent regulatory pathway used by migrating cortical neurons.
BCL11A is a triple-negative breast cancer gene with critical functions in stem and progenitor cells.
Khaled, Walid T; Choon Lee, Song; Stingl, John; Chen, Xiongfeng; Raza Ali, H; Rueda, Oscar M; Hadi, Fazal; Wang, Juexuan; Yu, Yong; Chin, Suet-Feung; Stratton, Mike; Futreal, Andy; Jenkins, Nancy A; Aparicio, Sam; Copeland, Neal G; Watson, Christine J; Caldas, Carlos; Liu, Pentao
2015-01-09
Triple-negative breast cancer (TNBC) has poor prognostic outcome compared with other types of breast cancer. The molecular and cellular mechanisms underlying TNBC pathology are not fully understood. Here, we report that the transcription factor BCL11A is overexpressed in TNBC including basal-like breast cancer (BLBC) and that its genomic locus is amplified in up to 38% of BLBC tumours. Exogenous BCL11A overexpression promotes tumour formation, whereas its knockdown in TNBC cell lines suppresses their tumourigenic potential in xenograft models. In the DMBA-induced tumour model, Bcl11a deletion substantially decreases tumour formation, even in p53-null cells and inactivation of Bcl11a in established tumours causes their regression. At the cellular level, Bcl11a deletion causes a reduction in the number of mammary epithelial stem and progenitor cells. Thus, BCL11A has an important role in TNBC and normal mammary epithelial cells. This study highlights the importance of further investigation of BCL11A in TNBC-targeted therapies.
Zhou, Jian; Yang, Yue; Zhang, Duo; Zhou, Liang; Tao, Lei; Lu, Li-Ming
2017-01-01
Objective We investigated the association between B-cell lymphoma/leukaemia 11A (BCL11A) rs11886868 and rs4671393 polymorphism, plasma BCL11A concentration, and the hazard of developing laryngeal squamous cell carcinoma (LSCC). Participants and method In this research, 330 LSCC patients, 310 healthy controls, and 155 vocal leukoplakia patients were genotyped for the BCL11A (rs11886868 C/T and rs4671393 A/G) genotypes by pyrosequencing; the BCL11A concentration was measured using ELISA. Results LSCC Patients had a notably higher occurrence of CT at rs11886868 (OR = 2.64, P = 0.025) than the control group; they also had higher GG at rs4671393 (OR = 2.53, P = 0.018). Advanced (III and IV) stage LSCC patients had a notably greater frequency of CT at rs11886868 than those with initial (I and II) stage LSCC (OR = 2.71, P = 0.044 vs. OR = 2.58, P = 0.051). Additionally, there was a 1.59 fold increase in susceptibility for initial stage LSCC related to the G allele (AG/GG) at rs4671393 (P = 0.005); while for patients of advanced stage LSCC the OR was 1.73 (P = 0.002). Moreover, the OR of lymph node metastasis patients at rs4671393 G alleles was 2.41 (P < 0.01); it was 1.38 (P = 0.035) in patients without lymph metastasis. Patients with high incidences of the rs4671393 variation genotype had high plasma BCL11A levels. Conclusions BCL11A rs11886868 and rs4671393 genotype variations and correspondingly high BCL11A plasma levels are related to LSCC, besides, differences in plasma levels and genotype distribution may be related to lymph node metastasis status and the stage of LSCC. PMID:28225775
BCL11A-siRNA对HEK293细胞增殖的影响%Influence of BCL11A-siRNA on HEK293 cell proliferation
Institute of Scientific and Technical Information of China (English)
高杨军; 胡小毛; 吴红; 何冬梅; 赵军; 李扬秋
2014-01-01
目的 设计靶向B细胞淋巴瘤/白血病11A基因的小干扰RNA(BCL1 1A-siRNA),并观察其对人胚胎肾细胞株HEK293细胞增殖的影响.方法 利用siRNA Target Finder工具,针对BCL11A设计合成siRNA319、siRNA585、siRNA2292、siRNA475.将HEK293细胞接种不含抗生素的培养基中,分为阳性对照组(PC组)、阴性对照组(NC组)、BCL11A-siRNA319组(si319组)、BCL11A-siRNA585组(si585组)、BCL11A-siRNA2292组(si2292组)、BCL11A-siR-NA475组(si475组)、空转组、细胞组.通过LipofectamineTM 2000,si319组将siRNA319、si585组将siRNA585、si2292组将siRNA2292、si475组将siRNA475分别转染HEK293细胞;转染后6h倒置荧光显微镜观察细胞转染情况并用流式细胞仪检测转染效率;转染后24、48、72 h,采用实时定量RT-PCR法观察BCL11A-siRNA对BCL11A基因表达的影响;CCK8法观察HEK293细胞体外增殖情况.结果 转染后24h,si585组、si2292组的HEK293细胞BCL11A基因表达降低,72 h逐渐恢复;si585组、si2292组细胞增殖受抑,与NC组、空转组、细胞组相比,P均＜0.05.结论 BCL11A-siRNA585及BCL11 A-siRNA2292可降低HEK293细胞中BCL1 1A基因表达,抑制细胞增殖.
Directory of Open Access Journals (Sweden)
ST. Motameni
1974-03-01
Full Text Available In the past, health planning in Iran has been carried out in the context of short-range economic plans. Although this mechanism has helped a great deal in the achievement of certain health plans however, the said scheme has been short in meeting the health objectives on a comprehensive basis. Most often, the heath programs have lost their values to the priority and cost effectiveness of economic plans. A brief review of heath planning in the past shows that the second development plan has been devoted to the establishment of new hospitals on a scattered pattern. The development of a coordinated hospital and health center system has been accepted and partly implemented during the third plan period. In the fourth plan the whole direction has changed towards the development of private hospitals on profit making basis, and now the fifth plan calls for the regionalized hospital system. Thus, one can say that the past twenty years have been spent to the experimentation of different schemes without a real long-range goal. In the past decade the World Health Organization has ventured in the development of health planning principles, but most of the efforts have been devoted to the short-range planning. The long-range health planning is not only a new look to the principles of planning, but a thorough examination of the time factor in health planning.
Directory of Open Access Journals (Sweden)
Amanda J Grieco
Full Text Available The molecular mechanisms governing γ-globin expression in a subset of fetal hemoglobin (α2γ2: HbF expressing red blood cells (F-cells and the mechanisms underlying the variability of response to hydroxyurea induced γ-globin expression in the treatment of sickle cell disease are not completely understood. Here we analyzed intra-person clonal populations of basophilic erythroblasts (baso-Es derived from bone marrow common myeloid progenitors in serum free cultures and report the level of fetal hemoglobin production in F-cells negatively correlates with expression of BCL11A, KLF1 and TAL1. We then examined the effects of hydroxyurea on these three transcription factors and conclude that a successful induction of γ-globin includes a reduction in BCL11A, KLF1 and TAL1 expression. These data suggests that expression changes in this transcription factor network modulate γ-globin expression in F-cells during steady state erythropoiesis and after induction with hydroxyurea.
Directory of Open Access Journals (Sweden)
Ambroise Wonkam
Full Text Available BACKGROUND: Genetic variation at loci influencing adult levels of HbF have been shown to modify the clinical course of sickle cell disease (SCD. Data on this important aspect of SCD have not yet been reported from West Africa. We investigated the relationship between HbF levels and the relevant genetic loci in 610 patients with SCD (98% HbSS homozygotes from Cameroon, and compared the results to a well-characterized African-American cohort. METHODS AND FINDINGS: Socio-demographic and clinical features were collected and medical records reviewed. Only patients >5 years old, who had not received a blood transfusion or treatment with hydroxyurea were included. Hemoglobin electrophoresis and a full blood count were conducted upon arrival at the hospital. RFLP-PCR was used to describe the HBB gene haplotypes. SNaPshot PCR, Capillary electrophoresis and cycle sequencing were used for the genotyping of 10 selected SNPs. Genetic analysis was performed with PLINK software and statistical models in the statistical package R. Allele frequencies of relevant variants at BCL11A were similar to those detected in African Americans; although the relationships with Hb F were significant (p <.001, they explained substantially less of the variance in HbF than was observed among African Americans (∼ 2% vs 10%. SNPs in HBS1L-MYB region (HMIP likewise had a significant impact on HbF, however, we did not find an association between HbF and the variations in HBB cluster and OR51B5/6 locus on chromosome 11p, due in part to the virtual absence of the Senegal and Indian Arab haplotypes. We also found evidence that selected SNPs in HBS1L-MYB region (HMIP and BCL11A affect both other hematological indices and rates of hospitalization. CONCLUSIONS: This study has confirmed the associations of SNPs in BCL11A and HBS1L-MYB and fetal haemoglobin in Cameroonian SCA patients; hematological indices and hospitalization rates were also associated with specific allelic variants.
Bernini, Caterina; Pogni, Rebecca; Basosi, Riccardo; Sinicropi, Adalgisa
2012-05-01
A catalytically active tryptophan radical has been demonstrated to be involved in the long-range electron transfer to the heme cofactor of lignin peroxidase (LiP) from Phanerochaete chrysosporium although no direct detection by EPR spectroscopy of the tryptophan radical intermediate has been reported to date. An engineering-based approach has been used to manipulate the microenvironment of the redox-active tryptophan site in LiP and Coprinus cinereus Peroxidase (CiP), allowing the direct evidence of the tryptophan radical species. In light of the newly available EPR experimental data, we performed a quantum mechanical/molecular mechanics computational study to characterize the tryptophan radicals in the above protein matrices as well as in pristine LiP. The nature of the tryptophan radicals is discussed together with the analysis of their environment with the aim of understanding the different behavior of pristine LiP in comparison with that of LiP and CiP variants.
Lettre, Guillaume; Sankaran, Vijay G; Bezerra, Marcos André C; Araújo, Aderson S; Uda, Manuela; Sanna, Serena; Cao, Antonio; Schlessinger, David; Costa, Fernando F; Hirschhorn, Joel N; Orkin, Stuart H
2008-08-19
Sickle cell disease (SCD) is a debilitating monogenic blood disorder with a highly variable phenotype characterized by severe pain crises, acute clinical events, and early mortality. Interindividual variation in fetal hemoglobin (HbF) expression is a known and potentially heritable modifier of SCD severity. High HbF levels are correlated with reduced morbidity and mortality. Common single nucleotide polymorphisms (SNPs) at the BCL11A and HBS1L-MYB loci have been implicated previously in HbF level variation in nonanemic European populations. We recently demonstrated an association between a BCL11A SNP and HbF levels in one SCD cohort [Uda M, et al. (2008) Proc Natl Acad Sci USA 105:1620-1625]. Here, we genotyped additional BCL11A SNPs, HBS1L-MYB SNPs, and an SNP upstream of (G)gamma-globin (HBG2; the XmnI polymorphism), in two independent SCD cohorts: the African American Cooperative Study of Sickle Cell Disease (CSSCD) and an SCD cohort from Brazil. We studied the effect of these SNPs on HbF levels and on a measure of SCD-related morbidity (pain crisis rate). We strongly replicated the association between these SNPs and HbF level variation (in the CSSCD, P values range from 0.04 to 2 x 10(-42)). Together, common SNPs at the BCL11A, HBS1L-MYB, and beta-globin (HBB) loci account for >20% of the variation in HbF levels in SCD patients. We also have shown that HbF-associated SNPs associate with pain crisis rate in SCD patients. These results provide a clear example of inherited common sequence variants modifying the severity of a monogenic disease.
STATISTICAL PROPERTIES OF LONG-RANGE CONTACTS IN GLOBULAR PROTEINS
Institute of Scientific and Technical Information of China (English)
Xiang-hong Wang; Jian-hong Ke; Mang-xiao Hu
2004-01-01
The analysis of residue-residue contacts in protein structures can shed some light on our understanding of the folding and stability of proteins. In this paper, we study the statistical properties of long-range and short-range residueresidue contacts of 91 globular proteins using CSU software and analyze the importance of long-range contacts in globular protein structure. There are many short-range and long-range contacts in globular proteins, and it is found that the average number of long-range contacts per residue is 5.63 and the percentage of residue-residue contacts which are involved in longrange ones is 59.4%. In more detail, the distribution of long-range contacts in different residue intervals is investigated and it is found that the residues occurring in the interval range of 4-10 residues apart in the sequence contribute more long-range contacts to the stability of globular protein. The number of long-range contacts per residue, which is a measure of ability to form residue-residue contacts, is also calculated for 20 different amino acid residues. It is shown that hydrophobic residues (including Leu, Val, Ile, Met, Phc, Tyr, Cys and Trp) having a large number of long-range contacts easily form long-range contacts, while the hydrophilic amino acids (including Ala, Gly, Thr, His, Glu, Gin, Asp, Asn, Lys, Ser, Arg, and Pro) form long-range contacts with more difficulty. The relationship between the Fauchere-Pliska hydrophobicity scale (FPH) and the number of short-range and long-range contacts per residue for 20 amino acid residues is also studied. An approximately linear relationship between the Fauchere-Pliska hydrophobicity scale (FPH) and the number of long-range contacts per residue CL is found and can be expressed as CiL= a + b x FPHwhere a = 5.04 and b = 1.23. These results can help us to understand the role of residue-residue contacts in globular protein structure.
Long-Range Nondestructive Testing System Project
National Aeronautics and Space Administration — This proposal is for the development of a long range, multi-point non-destructive system for the detection of subsurface flaws in metallic and composite materials of...
Remarks on long range interactions in simulations
Energy Technology Data Exchange (ETDEWEB)
Pollock, E L
1999-08-11
Long range interactions in periodic systems should be treated using the Ewald potential. For systems larger than a few hundred particles this is best calculated using the particle-particle, particle-mesh (P3M) method.
Photon assisted long-range tunneling
Energy Technology Data Exchange (ETDEWEB)
Gallego-Marcos, Fernando; Sánchez, Rafael; Platero, Gloria [Instituto de Ciencia de Materiales, CSIC, Cantoblanco, 28049 Madrid (Spain)
2015-03-21
We analyze long-range transport through an ac driven triple quantum dot with a single electron. Resonant transitions between separated and detuned dots are mediated by the exchange of n photons with the time-dependent field. An effective model is proposed in terms of second order (cotunneling) processes which dominate the long-range transport between the edge quantum dots. The ac field renormalizes the inter dot hopping, modifying the level hybridization. It results in a non-trivial behavior of the current with the frequency and amplitude of the external ac field.
Effect of Wind on Long Range Propagation in Shallow Water
Ainslie, M.A.
2004-01-01
Long range acoustic propagation in isothermal conditions is considered, involving multiple reflections from the sea surface. If the sea is calm there is almost perfect reflection and hence low loss. The effect of wind is to increase propagation loss due to the interaction with near-surface bubble cl
Resources and Long-Range Forecasts
Smith, Waldo E.
1973-01-01
The author argues that forecasts of quick depletion of resources in the environment as a result of overpopulation and increased usage may not be free from error. Ignorance still exists in understanding the recovery mechanisms of nature. Long-range forecasts are likely to be wrong in such situations. (PS)
Long-Range Collisions in Magnetized Plasmas
Dubin, D.
2015-12-01
Astrophysical (and earthbound) plasmas in strong magnetic fields exhibit collisional effects that are not described by classical collision theory nor by the standard collision operators, such as the Landau or Balescu-Lenard operators. These theories implicitly neglect "long-range" collisions, i.e. collisions with impact parameters large compared to the cyclotron radius. This presentation will review several important physical effects such collisions have on various phenomena, including cross-magnetic field diffusion, heat conduction, and collisional slowing parallel to the magnetic field. Long-range collisions are analyzed as guiding-centers moving in one-dimension along the magnetic field, with parallel energy and momentum transferred to particles on separate field lines through the screened Coulomb interaction. This causes cross-field heat transport that is independent of magnetic field strength B (as opposed to the classical 1/B2 scaling), and enhances the rate of collisional slowing parallel to B. The Coulomb interaction between guiding centers on different field lines also produces random ExB drifts that enhance cross-magnetic field diffusion compared to the classical theory. The theory of long-range guiding center collisions must also include the novel effect of "collisional caging": plasma noise causes two colliding guiding centers to diffuse in relative parallel velocity, reversing their motion along B and colliding several times before becoming uncorrelated. This further enhances cross-field diffusion from long-range collisions by a factor of three, and enhances parallel slowing by a factor of approximately 1.5.
DEFF Research Database (Denmark)
Norvell, J.C.; Als-Nielsen, Jens Aage
1970-01-01
The long-range order parameter M of β brass has been determined from measurements of the intensity of superlattice reflections of Bragg-scattered neutrons. Over the whole temperature range T=300 °K to T=Tc=736 °K, the data are in remarkable agreement with the prediction for the compressible Ising...... bcc lattice with only nearest-neighbor interactions. © 1970 The American Physical Society...
Long-Range Connections in Transportation Networks
Viana, Matheus P
2010-01-01
Since its recent introduction, the small-world effect has been identified in several important real-world systems. Frequently, it is a consequence of the existence of a few long-range connections, which dominate the original regular structure of the systems and implies each node to become accessible from other nodes after a small number of steps, typically of order $\\ell \\propto \\log N$. However, this effect has been observed in pure-topological networks, where the nodes have no spatial coordinates. In this paper, we present an alalogue of small-world effect observed in real-world transportation networks, where the nodes are embeded in a hree-dimensional space. Using the multidimensional scaling method, we demonstrate how the addition of a few long-range connections can suubstantially reduce the travel time in transportation systems. Also, we investigated the importance of long-range connections when the systems are under an attack process. Our findings are illustrated for two real-world systems, namely the L...
Long-range hybrid wedge plasmonic waveguide.
Zhang, Zhonglai; Wang, Jian
2014-11-03
We design a novel long-range hybrid wedge plasmonic (LRHWP) waveguide composed of two identical dielectric nanowires symmetrically placed on two opposed wedges of a diamond shaped metal wire. With strong coupling between the dielectric nanowire mode and long-range surface plasmon polariton (SPP) mode, both deep subwavelength mode confinement and low propagation loss are achieved. On one hand, when compared to the previous long-range hybrid SPP waveguide, LRHWP waveguide can achieve smaller mode size with similar propagation length; on the other hand, when compared to the previous hybrid wedge SPP waveguide, LRHWP waveguide can provide an order of magnitude longer propagation length with similar level of mode confinement. The designed LRHWP waveguide also features an overall advantage of one-order improvement of Figure of Merit. We further evaluate in detail the impacts of possible practical fabrication imperfections on the mode properties. The obtained results of mode properties show that the proposed LRHWP waveguide with an optimized wedge tip angle of 140 degree is fairly tolerant to practical fabrication errors in geometry parameters such as misalignment in the horizontal direction, asymmetry in the vertical direction, variation of wedge tip angle, tilt or rotation of metal wire, and variation of wedge tip curvature radius.
Long-range laser-illuminated imaging
Dayton, David C.; Browne, Stephen L.; Sandven, Steven C.; Gonglewski, John D.; Gallegos, Joe; Shilko, Michael L., Sr.
2000-11-01
We demonstrate the utility of laser illuminated imaging for clandestine night time surveillance from a simulated airborne platform at standoff ranges in excess 20 km. In order to reduce the necessary laser per pulse energy required for illumination at such long ranges, and to mitigate atmospheric turbulence effects on image resolution, we have investigated a unique multi-frame post-processing technique. It is shown that in the presence of atmospheric turbulence and coherent speckle effects, this approach can produce superior results to conventional scene flood illumination.
Long range predictability of atmospheric flows
Directory of Open Access Journals (Sweden)
R. Robert
2001-01-01
Full Text Available In the light of recent advances in 2D turbulence, we investigate the long range predictability problem of atmospheric flows. Using 2D Euler equations, we show that the full nonlinearity acting on a large number of degrees of freedom can, paradoxically, improve the predictability of the large scale motion, giving a picture opposite to the one largely popularized by Lorenz: a small local perturbation of the atmosphere will progressively gain larger and larger scales by nonlinear interaction and will finally cause large scale change in the atmospheric flow.
Emergent long-range couplings in arrays of fluid cells
Energy Technology Data Exchange (ETDEWEB)
Abraham, Douglas Bruce [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2014-08-07
We present a system exhibiting extraordinarily long-range cooperative effects, on a length scale far exceeding the bulk correlation length. We give a theoretical explanation of these phenomena based on the mesoscopic picture of phase coexistence in finite systems, which is confirmedly Monte Carlo (MC) simulation studies. Our work demonstrates that such action-at-a-distance can occur in classical systems involving simple or complex fluids, such as colloid-polymer mixtures, or ferromagnets.
Long range correlations in DNA sequences
Mohanty, A K
2002-01-01
The so called long range correlation properties of DNA sequences are studied using the variance analyses of the density distribution of a single or a group of nucleotides in a model independent way. This new method which was suggested earlier has been applied to extract slope parameters that characterize the correlation properties for several intron containing and intron less DNA sequences. An important aspect of all the DNA sequences is the properties of complimentarity by virtue of which any two complimentary distributions (like GA is complimentary to TC or G is complimentary to ATC) have identical fluctuations at all scales although their distribution functions need not be identical. Due to this complimentarity, the famous DNA walk representation whose statistical interpretation is still unresolved is shown to be a special case of the present formalism with a density distribution corresponding to a purine or a pyrimidine group. Another interesting aspect of most of the DNA sequences is that the factorial m...
Long Range Surface Plasmons in Multilayer Structures
Delfan, Aida
2013-01-01
We present a new strategy, based on a Fresnel coefficient pole analysis, for designing an asymmetric multilayer structure that supports long range surface plasmons (LRSP). We find that the electric field intensity in the metal layer of a multilayer LRSP structure can be even slightly smaller than in the metal layer of the corresponding symmetric LRSP structure, minimizing absorption losses and resulting in LRSP propagation lengths up to 2mm. With a view towards biosensing applications, we also present semi-analytic expressions for a standard surface sensing parameter in arbitrary planar resonant structures, and in particular show that for an asymmetric structure consisting of a gold film deposited on a multilayer of SiO2 and TiO2 a surface sensing parameter G = 1.28(1/nm) can be achieved.
Long-range interaction of anisotropic systems
Zhang, Junyi
2015-02-01
The first-order electrostatic interaction energy between two far-apart anisotropic atoms depends not only on the distance between them but also on their relative orientation, according to Rayleigh-Schrödinger perturbation theory. Using the first-order interaction energy and the continuum model, we study the long-range interaction between a pair of parallel pristine graphene sheets at zero temperature. The asymptotic form of the obtained potential density, &epsi:(D) &prop: ?D ?3 ?O(D?4), is consistent with the random phase approximation and Lifshitz theory. Accordingly, neglectance of the anisotropy, especially the nonzero first-order interaction energy, is the reason why the widely used Lennard-Jones potential approach and dispersion corrections in density functional theory give a wrong asymptotic form ε(D) &prop: ?D?4. © EPLA, 2015.
Stochastic processes and long range dependence
Samorodnitsky, Gennady
2016-01-01
This monograph is a gateway for researchers and graduate students to explore the profound, yet subtle, world of long-range dependence (also known as long memory). The text is organized around the probabilistic properties of stationary processes that are important for determining the presence or absence of long memory. The first few chapters serve as an overview of the general theory of stochastic processes which gives the reader sufficient background, language, and models for the subsequent discussion of long memory. The later chapters devoted to long memory begin with an introduction to the subject along with a brief history of its development, followed by a presentation of what is currently the best known approach, applicable to stationary processes with a finite second moment. The book concludes with a chapter devoted to the author’s own, less standard, point of view of long memory as a phase transition, and even includes some novel results. Most of the material in the book has not previously been publis...
Long range position and Orientation Tracking System
Energy Technology Data Exchange (ETDEWEB)
Armstrong, G.A.; Jansen, J.F.; Burks, B.L. [and others
1996-02-01
The long range Position and Orientation Tracking System is an active triangulation-based system that is being developed to track a target to a resolution of 6.35 mm (0.25 in.) and 0.009{degrees}(32.4 arcseconds) over a range of 13.72 m (45 ft.). The system update rate is currently set at 20 Hz but can be increased to 100 Hz or more. The tracking is accomplished by sweeping two pairs of orthogonal line lasers over infrared (IR) sensors spaced with known geometry with respect to one another on the target (the target being a rigid body attached to either a remote vehicle or a remote manipulator arm). The synchronization and data acquisition electronics correlates the time that an IR sensor has been hit by one of the four lasers and the angle of the respective mirror at the time of the hit. This information is combined with the known geometry of the IR sensors on the target to determine position and orientation of the target. This method has the advantage of allowing the target to be momentarily lost due to occlusions and then reacquired without having to return the target to a known reference point. The system also contains a camera with operator controlled lighting in each pod that allows the target to be continuously viewed from either pod, assuming their are no occlusions.
Long-range forecasting of intermittent streamflow
Directory of Open Access Journals (Sweden)
F. F. van Ogtrop
2011-01-01
Full Text Available Long-range forecasting of intermittent streamflow in semi-arid Australia poses a number of major challenges. One of the challenges relates to modelling zero, skewed, non-stationary, and non-linear data. To address this, a probabilistic statistical model to forecast streamflow 12 months ahead is applied to five semi-arid catchments in South Western Queensland. The model uses logistic regression through Generalised Additive Models for Location, Scale and Shape (GAMLSS to determine the probability of flow occurring in any of the systems. We then use the same regression framework in combination with a right-skewed distribution, the Box-Cox t distribution, to model the intensity (depth of the non-zero streamflows. Time, seasonality and climate indices, describing the Pacific and Indian Ocean sea surface temperatures, are tested as covariates in the GAMLSS model to make probabilistic 12-month forecasts of the occurrence and intensity of streamflow. The output reveals that in the study region the occurrence and variability of flow is driven by sea surface temperatures and therefore forecasts can be made with some skill.
Copulas and time series with long-ranged dependences
Chicheportiche, Rémy
2013-01-01
We review ideas on temporal dependences and recurrences in discrete time series from several areas of natural and social sciences. We revisit existing studies and redefine the relevant observables in the language of copulas (joint laws of the ranks). We propose that copulas provide an appropriate mathematical framework to study non-linear time dependences and related concepts - like aftershocks, Omori law, recurrences, waiting times. We also critically argue using this global approach that previous phenomenological attempts involving only a long-ranged autocorrelation function lacked complexity in that they were essentially mono-scale.
Long range node-strut analysis of trabecular bone microarchitecture
Schmah, T; Thomsen, J S; Saparin, P
2015-01-01
Purpose: We present a new morphometric measure of trabecular bone microarchitecture, called mean node strength (NdStr), which is part of a newly developed approach called long range node-strut analysis. Our general aim is to describe and quantify the apparent "latticelike" microarchitecture of the trabecular bone network. Methods: Similar in some ways to the topological node-strut analysis introduced by Garrahan et al. [J. Microsc. 142, 341-349 (1986)], our method is distinguished by an emphasis on long-range trabecular connectivity. Thus, while the topological classification of a pixel (after skeletonization) as a node, strut, or terminus, can be determined from the 3x3 neighborhood of that pixel, our method, which does not involve skeletonization, takes into account a much larger neighborhood. In addition, rather than giving a discrete classification of each pixel as a node, strut, or terminus, our method produces a continuous variable, node strength. The node strength is averaged over a region of interest ...
Long range node-strut analysis of trabecular bone microarchitecture
DEFF Research Database (Denmark)
Schmah, Tanya; Marwan, Norbert; Thomsen, Jesper Skovhus
2011-01-01
PURPOSE: We present a new morphometric measure of trabecular bone microarchitecture, called mean node strength (NdStr), which is part of a newly developed approach called long range node-strut analysis. Our general aim is to describe and quantify the apparent "latticelike" microarchitecture...... skeletonization) as a node, strut, or terminus, can be determined from the 3 × 3 neighborhood of that pixel, our method, which does not involve skeletonization, takes into account a much larger neighborhood. In addition, rather than giving a discrete classification of each pixel as a node, strut, or terminus, our...... comparison of images with similar BMD but with very different NdStr values suggests that the latter measure has successfully quantified the prevalence of the "latticelike" microarchitecture apparent in the image. Moreover, we found a strong correlation (r = 0.62) between NdStr and the conventional node...
Theory of long-range ultracold atom-molecule photoassociation
Pérez-Ríos, Jesús; Dulieu, Olivier
2015-01-01
The creation of ultracold molecules is currently limited to diatomic species. In this letter we present a theoretical description of the photoassociation of ultracold atoms and molecules to create ultracold excited triatomic molecules, thus being a novel example of light-assisted ultracold chemical reaction. The calculation of the photoassociation rate of ultracold Cs atoms with ultracold Cs$_2$ molecules in their rovibrational ground state is reported, based on the solution of the quantum dynamics involving the atom-molecule long-range interactions, and assuming a model potential for the short-range physics. The rate for the formation of excited Cs$_3$ molecules is predicted to be comparable with currently observed atom-atom photoassociation rates. We formulate an experimental proposal to observe this process relying on the available techniques of optical lattices and standard photoassociation spectroscopy.
A relation between long-range correlation and dielectric anomaly
Institute of Scientific and Technical Information of China (English)
张磊; 钟维烈; 王春雷; 彭毅萍
1999-01-01
A double-well potential model is established to explain the dielectric anomaly of ferroelectrics. The dielectric constant consists of two parts. One part is independent of the long-range correlation, following 1/T law. The other part originates from the long-range correlation, and can be described by the correlation length well. The deviation from Curie-Weiss law in a small size sample originates from the decrease of the long-range correlation.
Nanoimprinted Long-range Surface Plasmon Polariton Waveguide Components
DEFF Research Database (Denmark)
Johansen, Dan Mario; Boltasseva, A.; Nielsen, Theodor;
2006-01-01
We report on the fabrication by nanoimprint lithography (NIL) and performance of metal stripe waveguides embedded in a polymer, capable of supporting long-range surface plasmon polariton (LRSPP) propagation.......We report on the fabrication by nanoimprint lithography (NIL) and performance of metal stripe waveguides embedded in a polymer, capable of supporting long-range surface plasmon polariton (LRSPP) propagation....
Report of the Long-Range Planning Committee
Energy Technology Data Exchange (ETDEWEB)
1984-07-01
This is the final report of the Long-Range Planning Committee of the Lawrence Livermore National Laboratory. It describes the make-up, purpose, working assumptions, and activities of the Committee and discusses the work done by the Committee on defense matters, energy, a number of additional topics, and future long-range planning activities.
Degeneracy and long-range correlation: A simulation study
Directory of Open Access Journals (Sweden)
Marmelat Vivien
2011-12-01
Full Text Available We present in this paper a simulation study that aimed at evidencing a causal relationship between degeneracy and long-range correlations. Long-range correlations represent a very specific form of fluctuations that have been evidenced in the outcomes time series produced by a number of natural systems. Long-range correlations are supposed to sign the complexity, adaptability and flexibility of the system. Degeneracy is defined as the ability of elements that are structurally different to perform the same function, and is presented as a key feature for explaining the robustness of complex systems. We propose a model able to generate long-range correlated series, and including a parameter that account for degeneracy. Results show that a decrease in degeneracy tends to reduce the strength of long-range correlation in the series produced by the model.
EFFECTS OF LONG-RANGE INTERACTIONS ON THE FERROELECTRIC FILM
Institute of Scientific and Technical Information of China (English)
吴银忠; 李振亚
2001-01-01
The effect of long-range interactions on the spontaneous polarization and the Curie temperature of the ferroelectricfilm is investigated by use of the Landau theory. On the assumption that the nearest-n eighbour interaction remains constant, we find that the spontaneous polarization and the phase transition temperature increase with the enhancement of the long-range interactions. In the case of positive extrapolation length, the critical thickness of the ferroelectric film,in which a size-driven phase transition occurs, decreases with the enhancement of the long-range interactions.
Truncated Long-Range Percolation on Oriented Graphs
van Enter, A. C. D.; de Lima, B. N. B.; Valesin, D.
2016-07-01
We consider different problems within the general theme of long-range percolation on oriented graphs. Our aim is to settle the so-called truncation question, described as follows. We are given probabilities that certain long-range oriented bonds are open; assuming that the sum of these probabilities is infinite, we ask if the probability of percolation is positive when we truncate the graph, disallowing bonds of range above a possibly large but finite threshold. We give some conditions in which the answer is affirmative. We also translate some of our results on oriented percolation to the context of a long-range contact process.
Long Range Water Management Plan : Lacreek National Wildlife Refuge
US Fish and Wildlife Service, Department of the Interior — This Long-Range Water Management Plan for Lacreek National Wildlife Refuge begins with a history of precipitation, water levels, wildlife use, disease, water...
Long-Range and Strategic Planning at Michigan State.
Carlisle, E. Fred
1986-01-01
On Feb. 6, 1961, the Board of Trustees of Michigan State University declared that MSU was "in a state of financial crisis". The development and implementation of long-range planning at Michigan State since the crisis is discussed. (MLW)
Exciton-Phonon Dynamics with Long-Range Interaction
Laskin, Nick
2011-01-01
Exciton-phonon dynamics on a 1D lattice with long-range exciton-exciton interaction have been introduced and elaborated. Long-range interaction leads to a nonlocal integral term in the motion equation of the exciton subsystem if we go from discrete to continuous space. In some particular cases for power-law interaction, the integral term can be expressed through a fractional order spatial derivative. A system of two coupled equations has been obtained, one is a fractional differential equation for the exciton subsystem, the other is a standard differential equation for the phonon subsystem. These two equations present a new fundamental framework to study nonlinear dynamics with long-range interaction. New approaches to model the impact of long-range interaction on nonlinear dynamics are: fractional generalization of Zakharov system, Hilbert-Zakharov system, Hilbert-Ginzburg-Landau equation and nonlinear Hilbert-Schrodinger equation. Nonlinear fractional Schrodinger equation and fractional Ginzburg-Landau equa...
Lagrangian formulation of continuum with internal long-range interactions
Institute of Scientific and Technical Information of China (English)
无
2011-01-01
Based on a new definition of nonlocal variable,this paper establishes the Lagrangian formulation for continuum with internal long-range interactions.Distinguished from the existing theories,the nonlocal term in the Lagrangian formulation automatically satisfies the zero mean condition determined by the action and reaction law.By this formulation,elastic wave in a rod with the internal long-range interactions is investigated.The dispersion of the elastic wave is predicted.
Observed Orbit Effects during Long Range Beam-Beam Studies
Alemany, R; Buffat, X; Calaga, R; Fitterer, M; Giachino, R; Hemelsoet, GH; Herr, W; Papotti, G; Pieloni, T; Poyer, M; Schaumann, M; Trad, G; Wollmann, D
2012-01-01
Possible limitations due to long range beam-beam effects at the LHC have been studied and are presented in this note. With a larger number of bunches and collisions in all interaction points, the crossing angles were reduced to enhance long range beam-beam effects. The analysis of the effects on the dynamic aperture and losses are documented in [1]. This note concentrates on the bunch-by-bunch orbit effects observed during the experiment.
Long-range eye tracking: A feasibility study
Energy Technology Data Exchange (ETDEWEB)
Jayaweera, S.K.; Lu, Shin-yee
1994-08-24
The design considerations for a long-range Purkinje effects based video tracking system using current technology is presented. Past work, current experiments, and future directions are thoroughly discussed, with an emphasis on digital signal processing techniques and obstacles. It has been determined that while a robust, efficient, long-range, and non-invasive eye tracking system will be difficult to develop, such as a project is indeed feasible.
Current fluctuations in stochastic systems with long-range memory
Energy Technology Data Exchange (ETDEWEB)
Harris, R J; Touchette, H [School of Mathematical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS (United Kingdom)], E-mail: rosemary.harris@qmul.ac.uk, E-mail: h.touchette@qmul.ac.uk
2009-08-28
We propose a method to calculate the large deviations of current fluctuations in a class of stochastic particle systems with history-dependent rates. Long-range temporal correlations are seen to alter the speed of the large deviation function in analogy with long-range spatial correlations in equilibrium systems. We give some illuminating examples and discuss the applicability of the Gallavotti-Cohen fluctuation theorem. (fast track communication)
Understanding Long-Range Correlations in DNA sequences
Li, W; Kaneko, K; Wentian Li; Thomas G Marr; Kunihiko Kaneko
1994-01-01
Abstract: In this paper, we review the literature on statistical long-range correlation in DNA sequences. We examine the current evidence for these correlations, and conclude that a mixture of many length scales (including some relatively long ones) in DNA sequences is responsible for the observed 1/f-like spectral component. We note the complexity of the correlation structure in DNA sequences. The observed complexity often makes it hard, or impossible, to decompose the sequence into a few statistically stationary regions. We suggest that, based on the complexity of DNA sequences, a fruitful approach to understand long-range correlation is to model duplication, and other rearrangement processes, in DNA sequences. One model, called ``expansion-modification system", contains only point duplication and point mutation. Though simplistic, this model is able to generate sequences with 1/f spectra. We emphasize the importance of DNA duplication in its contribution to the observed long-range correlation in DNA sequen...
Long-range interactions in lattice field theory
Energy Technology Data Exchange (ETDEWEB)
Rabin, J.M.
1981-06-01
Lattice quantum field theories containing fermions can be formulated in a chirally invariant way provided long-range interactions are introduced. It is established that in weak-coupling perturbation theory such a lattice theory is renormalizable when the corresponding continuum theory is, and that the continuum theory is indeed recovered in the perturbative continuum limit. In the strong-coupling limit of these theories one is led to study an effective Hamiltonian describing a Heisenberg antiferromagnet with long-range interactions. Block-spin renormalization group methods are used to find a critical rate of falloff of the interactions, approximately as inverse distance squared, which separates a nearest-neighbor-antiferromagnetic phase from a phase displaying identifiable long-range effects. A duality-type symmetry is present in some block-spin calculations.
Long-range oil and gas forecasting methodologies: literature survey
Energy Technology Data Exchange (ETDEWEB)
Cherniavsky, E.A.
1980-08-01
Performance of long-range energy system analyses requires the capability to project conventional domestic oil and gas supplies in the long term. The objective of the Long-range Forecasting Methodology project is to formulate an approach to this problem which will be compatible with the principal tool employed by the Energy Information Administration of the Department of Energy for long-range energy system analyses, the Long-term Energy Analysis Package (LEAP). This paper reports on projection methodologies that have appeared in the literature, evaluates them in terms of their applicability to the LEAP framework, and discusses the principal determinants of conventional domestic oil and gas supply in the long run.
Long-range dependence in Interest Rates and Monetary Policy
Cajueiro, D O; Cajueiro, Daniel O.; Tabak, Benjamin M.
2006-01-01
This paper studies the dynamics of Brazilian interest rates for short-term maturities. The paper employs developed techniques in the econophysics literature and tests for long-range dependence in the term structure of these interest rates for the last decade. Empirical results suggest that the degree of long-range dependence has changed over time due to changes in monetary policy, specially in the short-end of the term structure of interest rates. Therefore, we show that it is possible to identify monetary arrangements using these techniques from econophysics.
Helioseismology with long-range dark matter-baryon interactions
DEFF Research Database (Denmark)
Lopes, I.; Panci, Paolo; Silk, J.
2014-01-01
Assuming the existence of a primordial asymmetry in the dark sector, we study how long-range dark matter (DM)-baryon interactions, induced by the kinetic mixing of a new U(1) gauge boson and a photon, affect the evolution of the Sun and, in turn, the sound speed the profile obtained from...... the agreement between the best solar model and the helioseismic data without being excluded by direct detection experiments. In particular, the LUX detector will soon be able to either constrain or confirm our best-fit solar model in the presence of a dark sector with long-range interactions that reconcile...
Long-range stresses associated with boundaries in deformed materials
DEFF Research Database (Denmark)
Leffers, T.
1995-01-01
around the boundaries, a population which, because of the long-range stresses associated, does not represent a perfect LEDS, but the deviation is moderate. For polycrystals with flat grains and for polycrystals with the grains subdivided into flat bands the geometrically necessary dislocations may remain...... in the (grain or band) boundaries, but they still represent a certain, moderate deviation from LEDS. A distinction is made between two contributions from the geometrically necessary dislocations to hardening: conservative hardening which is associated with long-range stresses and frictional hardening which...
Strategic Long Range Planning for Universities. AIR Forum 1980 Paper.
Baker, Michael E.
The use of strategic long-range planning at Carnegie-Mellon University (CMU) is discussed. A structure for strategic planning analysis that integrates existing techniques is presented, and examples of planning activities at CMU are included. The key concept in strategic planning is competitive advantage: if a university has a competitive…
Algebraic Approach to the N-Body Long Range Scattering
Dereziński, Jan
It is proven that if J, h are bounded continuous functions and H is an N-body Schrödinger operator then there exists s-lim limits {t-> ±∞ } eitH J ((x)/(t))h (H)e-itH. Limits of this form are used to study the N-body long range scattering.
The long-range electromobility; Die Langstrecken-Elektromobilitaet
Energy Technology Data Exchange (ETDEWEB)
Burkert, Andreas
2013-05-01
The recent advances in the fuel cell technology prompted the automotive developers to bring to design hybrid electric vehicles with a fuel cell and a lithium-ion battery. Thus, the long-range electric mobility is possible at a short refueling time simultaneously. In addition, the lithium battery is suitable for preconditioning of the hydrogen fuel cell.
Long-range interactions in dilute granular systems
Müller, Micha-Klaus
2008-01-01
In this thesis, on purpose, we focussed on the most challenging, longest ranging potentials. We analyzed granular media of low densities obeying 1/r long-range interaction potentials between the granules. Such systems are termed granular gases and differ in their behavior from ordinary gases by diss
SEGMENTATION AND QUALITY ANALYSIS OF LONG RANGE CAPTURED IRIS IMAGE
Directory of Open Access Journals (Sweden)
Anand Deshpande
2016-05-01
Full Text Available The iris segmentation plays a major role in an iris recognition system to increase the performance of the system. This paper proposes a novel method for segmentation of iris images to extract the iris part of long range captured eye image and an approach to select best iris frame from the iris polar image sequences by analyzing the quality of iris polar images. The quality of iris image is determined by the frequency components present in the iris polar images. The experiments are carried out on CASIA-long range captured iris image sequences. The proposed segmentation method is compared with Hough transform based segmentation and it has been determined that the proposed method gives higher accuracy for segmentation than Hough transform.
Optical measurements of long-range protein vibrations
Acbas, Gheorghe; Niessen, Katherine A.; Snell, Edward H.; Markelz, A. G.
2014-01-01
Protein biological function depends on structural flexibility and change. From cellular communication through membrane ion channels to oxygen uptake and delivery by haemoglobin, structural changes are critical. It has been suggested that vibrations that extend through the protein play a crucial role in controlling these structural changes. While nature may utilize such long-range vibrations for optimization of biological processes, bench-top characterization of these extended structural motions for engineered biochemistry has been elusive. Here we show the first optical observation of long-range protein vibrational modes. This is achieved by orientation-sensitive terahertz near-field microscopy measurements of chicken egg white lysozyme single crystals. Underdamped modes are found to exist for frequencies >10 cm-1. The existence of these persisting motions indicates that damping and intermode coupling are weaker than previously assumed. The methodology developed permits protein engineering based on dynamical network optimization.
Temperature inversion in long-range interacting systems.
Teles, Tarcísio N; Gupta, Shamik; Di Cintio, Pierfrancesco; Casetti, Lapo
2015-08-01
Temperature inversions occur in nature, e.g., in the solar corona and in interstellar molecular clouds: Somewhat counterintuitively, denser parts of the system are colder than dilute ones. We propose a simple and appealing way to spontaneously generate temperature inversions in systems with long-range interactions, by preparing them in inhomogeneous thermal equilibrium states and then applying an impulsive perturbation. In similar situations, short-range systems would typically relax to another thermal equilibrium, with a uniform temperature profile. By contrast, in long-range systems, the interplay between wave-particle interaction and spatial inhomogeneity drives the system to nonequilibrium stationary states that generically exhibit temperature inversion. We demonstrate this mechanism in a simple mean-field model and in a two-dimensional self-gravitating system. Our work underlines the crucial role the range of interparticle interaction plays in determining the nature of steady states out of thermal equilibrium.
Conformal invariance in the long-range Ising model
Energy Technology Data Exchange (ETDEWEB)
Paulos, Miguel F. [CERN, Theory Group, Geneva (Switzerland); Rychkov, Slava, E-mail: slava.rychkov@lpt.ens.fr [CERN, Theory Group, Geneva (Switzerland); Laboratoire de Physique Théorique de l' École Normale Supérieure (LPTENS), Paris (France); Faculté de Physique, Université Pierre et Marie Curie (UPMC), Paris (France); Rees, Balt C. van [CERN, Theory Group, Geneva (Switzerland); Zan, Bernardo [Institute of Physics, Universiteit van Amsterdam, Amsterdam (Netherlands)
2016-01-15
We consider the question of conformal invariance of the long-range Ising model at the critical point. The continuum description is given in terms of a nonlocal field theory, and the absence of a stress tensor invalidates all of the standard arguments for the enhancement of scale invariance to conformal invariance. We however show that several correlation functions, computed to second order in the epsilon expansion, are nontrivially consistent with conformal invariance. We proceed to give a proof of conformal invariance to all orders in the epsilon expansion, based on the description of the long-range Ising model as a defect theory in an auxiliary higher-dimensional space. A detailed review of conformal invariance in the d-dimensional short-range Ising model is also included and may be of independent interest.
Conformal invariance in the long-range Ising model
Directory of Open Access Journals (Sweden)
Miguel F. Paulos
2016-01-01
Full Text Available We consider the question of conformal invariance of the long-range Ising model at the critical point. The continuum description is given in terms of a nonlocal field theory, and the absence of a stress tensor invalidates all of the standard arguments for the enhancement of scale invariance to conformal invariance. We however show that several correlation functions, computed to second order in the epsilon expansion, are nontrivially consistent with conformal invariance. We proceed to give a proof of conformal invariance to all orders in the epsilon expansion, based on the description of the long-range Ising model as a defect theory in an auxiliary higher-dimensional space. A detailed review of conformal invariance in the d-dimensional short-range Ising model is also included and may be of independent interest.
Long-range boundary effects in simple fluids
Nieuwoudt, J. C.; Kirkpatrick, T. R.; Dorfman, J. R.
1984-01-01
We discuss long-range boundary effects in simple two- or three-dimensional fluids. These boundary effects are due to the existence of long-range correlations in nonequilibrium fluids and can be computed either by means of kinetic theory or phenomenological mode-coupling theories. In particular, we use kinetic theory to compute the stress tensor and heat flux vector for a fluid in a nonequilibrium steady state in a finite geometry and show that both the effective shear viscosity and effective heat conductivity have contributions due to the walls of the container that influence the behavior of the system far into the fluid. We also show that the mechanocaloric effect is present in the bulk of a three-dimensional fluid and that there are normal stresses in a fluid whenever the temperature gradient is nonzero.
Observation of Prethermalization in Long-Range Interacting Spin Chains
Neyenhuis, B; Lee, A C; Zhang, J; Richerme, P; Hess, P W; Gong, Z -X; Gorshkov, A V; Monroe, C
2016-01-01
Statistical mechanics can predict thermal equilibrium states for most classical systems, but for an isolated quantum system there is no general understanding on how equilibrium states dynamically emerge from the microscopic Hamiltonian. For instance, quantum systems that are near-integrable usually fail to thermalize in an experimentally realistic time scale and, instead, relax to quasi-stationary prethermal states that can be described by statistical mechanics when approximately conserved quantities are appropriately included in a generalized Gibbs ensemble (GGE). Here we experimentally study the relaxation dynamics of a chain of up to 22 spins evolving under a long-range transverse field Ising Hamiltonian following a sudden quench. For sufficiently long-ranged interactions the system relaxes to a new type of prethermal state that retains a strong memory of the initial conditions. In this case, the prethermal state cannot be described by a GGE, but rather arises from an emergent double-well potential felt by...
Learning Long-range Terrain Perception for Autonomous Mobile Robots
Directory of Open Access Journals (Sweden)
Mingjun Wang
2010-02-01
Full Text Available Long-range terrain perception has a high value in performing efficient autonomous navigation and risky intervention tasks for field robots, such as earlier recognition of hazards, better path planning, and higher speeds. However, Stereo-based navigation systems can only perceive near-field terrain due to the nearsightedness of stereo vision. Many near-to-far learning methods, based on regions' appearance features, are proposed to predict the far-field terrain. We proposed a statistical prediction framework to enhance long-range terrain perception for autonomous mobile robots. The main difference between our solution and other existing methods is that our framework not only includes appearance features as its prediction basis, but also incorporates spatial relationships between terrain regions in a principled way. The experiment results show that our framework outperforms other existing approaches in terms of accuracy, robustness and adaptability to dynamic unstructured outdoor environments.
Long range anti-ferromagnetic spin model for prebiotic evolution
Energy Technology Data Exchange (ETDEWEB)
Nokura, Kazuo [Shonan Institute of Technology, Fujisawa 251-8511 (Japan)
2003-11-28
I propose and discuss a fitness function for one-dimensional binary monomer sequences of macromolecules for prebiotic evolution. The fitness function is defined by the free energy of polymers in the high temperature random coil phase. With repulsive interactions among the same kind of monomers, the free energy in the high temperature limit becomes the energy function of the one-dimensional long range anti-ferromagnetic spin model, which is shown to have a dynamical phase transition and glassy states.
The long range distributed fiber raman photon temperature sensor
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
A 31 km long range distributed optical fiber Raman photon temperature sensor (DOFRPTS) system have been developed based on temperature effect of the amplified spontaneous Raman scattering in fiber, and using fiber laser as a pumped source. The results show that temperature measuring uncertainty is ±2 ℃, temperature resolution is 0.1 ℃, measurement time is 432 s, spatial resolution is less than 4 m.
On the search for new long-range forces
Okun, Lev Borisovich
1980-01-01
The hypothesis is discussed of the existence of new long-range forces in addition to gravitational and electromagnetic forces. It is assumed that the forces act between massive elementary particles of a new type which have not been observed hitherfore experimentally. A search for such particles could be carried out by means of exact and systematic gravimetric measurements on the surface of the Earth as well as in the solar system. (11 refs).
Long-Range Ballistic Missile Defense in Europe
2010-04-26
Standard Missile 3) missile defenses. Czech President Vaclav Klaus pronounced himself unsurprised by the announcement, and assured that he was “100...was holding the six-month revolving European Union (EU) presidency. On May 15, President Vaclav Klaus announced the installation of an interim...September 17, 2009. 5 Withdrawal From Radar No Cooling of Czech-U.S. Relations – Klaus . CTK Daily News. September 17, 2009. . Long-Range Ballistic Missile
Extreme long range process effects characterization and compensation
Figueiro, Thiago; Browning, Clyde; Thornton, Martin J.; Vannuffel, Cyril; Choi, Kang-Hoon; Hohle, Christoph; Tortai, Jean-Herve; Schiavone, Patrick
2013-10-01
Proximity Effects in electron beam lithography impact feature dimensions, pattern fidelity and uniformity. These effects are addressed using a mathematical model representing the radial exposure intensity distribution induced by a point electron source, commonly named as the Point Spread Function (PSF). PSF models are usually employed for predicting and compensating for effects up to 15μm. It is well known that there are also some process related phenomena that impact pattern uniformity that have a longer range, namely CMP effects, fogging, etc. Performing proximity effects corrections can result in lengthy run times as file size and pattern densities continue to increase exponentially per technology node. Running corrections for extreme long range phenomena becomes computational and file size prohibitive. Nevertheless, since extreme long range may reach up several millimeters, and new technology nodes require a high level of precision, a strategy for predicting and compensating these phenomena is crucial. In this paper a set of test patterns are presented in order to verify and calibrate the so called extreme long range effects in the electron beam lithography. Moreover, a strategy to compensate for extreme long range effects based on the pattern density is presented. Since the evaluation is based on a density map instead of the actual patterns, the computational effort is feasible. The proposed method may be performed off-line (in contrast to machine standard in-line correction). The advantage of employing off-line compensation relies on enhancing the employ of dose and/or geometry modulation. This strategy also has the advantage of being completely decoupled from other e-beam writer's internal corrections (like Fogging Effect Correction - FEC).
Long-range electrostatic screening in ionic liquids.
Gebbie, Matthew A; Dobbs, Howard A; Valtiner, Markus; Israelachvili, Jacob N
2015-06-16
Electrolyte solutions with high concentrations of ions are prevalent in biological systems and energy storage technologies. Nevertheless, the high interaction free energy and long-range nature of electrostatic interactions makes the development of a general conceptual picture of concentrated electrolytes a significant challenge. In this work, we study ionic liquids, single-component liquids composed solely of ions, in an attempt to provide a novel perspective on electrostatic screening in very high concentration (nonideal) electrolytes. We use temperature-dependent surface force measurements to demonstrate that the long-range, exponentially decaying diffuse double-layer forces observed across ionic liquids exhibit a pronounced temperature dependence: Increasing the temperature decreases the measured exponential (Debye) decay length, implying an increase in the thermally driven effective free-ion concentration in the bulk ionic liquids. We use our quantitative results to propose a general model of long-range electrostatic screening in ionic liquids, where thermally activated charge fluctuations, either free ions or correlated domains (quasiparticles), take on the role of ions in traditional dilute electrolyte solutions. This picture represents a crucial step toward resolving several inconsistencies surrounding electrostatic screening and charge transport in ionic liquids that have impeded progress within the interdisciplinary ionic liquids community. More broadly, our work provides a previously unidentified way of envisioning highly concentrated electrolytes, with implications for diverse areas of inquiry, ranging from designing electrochemical devices to rationalizing electrostatic interactions in biological systems.
Admission control with long-range dependence traffic input
Institute of Scientific and Technical Information of China (English)
RAO Yun-hua; ZOU Xue-cheng
2005-01-01
The admission control scheme is investigated for a FIFO self-similar queuing system with Quality of Service (QoS) performance guarantees. Since the self-similar queuing system performance analysis is often carried out under the condition of infinite buffer, it is difficult to deduce the upper boundary of buffer overflow probability. To overcome this shortcoming, a simple overflow condition is proposed, which defines a buffer overflow occurrence whenever the arrival rate exceeds the service rate. The analytic formula for the buffer overflow probability upper boundary is easily obtained under this condition. The required bandwidth upper boundary with long-range dependence input and determined overflow probability is then derived from this formula. Based on the above analytic formulas, the upper boundaries of the admission control regions for homogeneous and heterogeneous long-range dependence traffic sources are separately obtained. Finally, an effective admission control scheme for long-range dependence input is proposed. Simulation studies with real traffic have confirmed the validity of these results.
ENSEMBLE methods to reconcile disparate national long range dispersion forecasting
Energy Technology Data Exchange (ETDEWEB)
Mikkelsen, T.; Galmarini, S.; Bianconi, R.; French, S. (eds.)
2003-11-01
ENSEMBLE is a web-based decision support system for real-time exchange and evaluation of national long-range dispersion forecasts of nuclear releases with cross-boundary consequences. The system is developed with the purpose to reconcile among disparate national forecasts for long-range dispersion. ENSEMBLE addresses the problem of achieving a common coherent strategy across European national emergency management when national long-range dispersion forecasts differ from one another during an accidental atmospheric release of radioactive material. A series of new decision-making 'ENSEMBLE' procedures and Web-based software evaluation and exchange tools have been created for real-time reconciliation and harmonisation of real-time dispersion forecasts from meteorological and emergency centres across Europe during an accident. The new ENSEMBLE software tools is available to participating national emergency and meteorological forecasting centres, which may choose to integrate them directly into operational emergency information systems, or possibly use them as a basis for future system development. (au)
Long-Range Forces in Direct Dark Matter Searches
Fornengo, N; Regis, M
2011-01-01
We discuss the positive indications of a possible dark matter signal in direct detection experiments in terms of a mechanism of interaction between the dark matter particle and the nuclei occurring via the exchange of a light mediator, resulting in a long-range interaction. We analyze the annual modulation results observed by the DAMA and CoGeNT experiments and the observed excess of events of CRESST. In our analysis, we discuss the relevance of uncertainties related to the velocity distribution of galactic dark matter and to the channeling effect in NaI. We find that a long-range force is a viable mechanism, which can provide full agreement between the reconstructed dark matter properties from the various experimental data sets, especially for masses of the light mediator in the 10-30 MeV range and a light dark matter with a mass around 10 GeV. The relevant bounds on the light mediator mass and scattering cross section are then derived, should the annual modulation effects be due to this class of long-range ...
Acceleration of evolutionary spread by long-range dispersal.
Hallatschek, Oskar; Fisher, Daniel S
2014-11-18
The spreading of evolutionary novelties across populations is the central element of adaptation. Unless populations are well mixed (like bacteria in a shaken test tube), the spreading dynamics depend not only on fitness differences but also on the dispersal behavior of the species. Spreading at a constant speed is generally predicted when dispersal is sufficiently short ranged, specifically when the dispersal kernel falls off exponentially or faster. However, the case of long-range dispersal is unresolved: Although it is clear that even rare long-range jumps can lead to a drastic speedup--as air-traffic-mediated epidemics show--it has been difficult to quantify the ensuing stochastic dynamical process. However, such knowledge is indispensable for a predictive understanding of many spreading processes in natural populations. We present a simple iterative scaling approximation supported by simulations and rigorous bounds that accurately predicts evolutionary spread, which is determined by a trade-off between frequency and potential effectiveness of long-distance jumps. In contrast to the exponential laws predicted by deterministic "mean-field" approximations, we show that the asymptotic spatial growth is according to either a power law or a stretched exponential, depending on the tails of the dispersal kernel. More importantly, we provide a full time-dependent description of the convergence to the asymptotic behavior, which can be anomalously slow and is relevant even for long times. Our results also apply to spreading dynamics on networks with a spectrum of long-range links under certain conditions on the probabilities of long-distance travel: These are relevant for the spread of epidemics.
ATHLETE Mobility Performance in Long-Range Traverse
Townsend, Julie
2011-01-01
The All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE) is a modular mobility and manipulation platform being developed to support NASA operations in a variety of missions, including exploration of planetary surfaces. The agile system consists of a symmetrical arrangement of six limbs, each with seven articulated degrees of freedom and a powered wheel. This design enables transport of bulky payloads over a wide range of terrains and is envisioned as a tool to mobilize habitats, power-generation equipment, and other supplies for long-range exploration and outpost construction.
Network resource allocation attack detection with long range dependence
Institute of Scientific and Technical Information of China (English)
WANG Xin; FANG Bin-xing
2007-01-01
The approach of traffic abnormality detection of network resource allocation attack did not have reliable signatures to depict abnormality and identify them. However, it is crucial for us to detect attacks accurately.The technique that we adopted is inspired by long range dependence ideas. We use the number of packet arrivals of a flow in fixed-length time intervals as the signal and attempt to extend traffic invariant "self-similarity".We validate the effectiveness of the approach with simulation and trace analysis.
Long-range plasmonic waveguides with hyperbolic cladding.
Babicheva, Viktoriia E; Shalaginov, Mikhail Y; Ishii, Satoshi; Boltasseva, Alexandra; Kildishev, Alexander V
2015-11-30
We study plasmonic waveguides with dielectric cores and hyperbolic multilayer claddings. The proposed design provides better performance in terms of propagation length and mode confinement in comparison to conventional designs, such as metal-insulator-metal and insulator-metal-insulator plasmonic waveguides. We show that the proposed structures support long-range surface plasmon modes, which exist when the permittivity of the core matches the transverse effective permittivity component of the metamaterial cladding. In this regime, the surface plasmon polaritons of each cladding layer are strongly coupled, and the propagation length can be on the order of a millimeter.
Long-range plasmonic waveguides with hyperbolic cladding
DEFF Research Database (Denmark)
Babicheva, Viktoriia E.; Shalaginov, Mikhail Y.; Ishii, Satoshi;
2015-01-01
We study plasmonic waveguides with dielectric cores and hyperbolic multilayer claddings. The proposed design provides better performance in terms of propagation length and mode confinement in comparison to conventional designs, such as metal-insulator-metal and insulator-metal-insulator plasmonic...... waveguides. We show that the proposed structures support long-range surface plasmon modes, which exist when the permittivity of the core matches the transverse effective permittivity component of the metamaterial cladding. In this regime, the surface plasmon polaritons of each cladding layer are strongly...
Long-range dependence and sea level forecasting
Ercan, Ali; Abbasov, Rovshan K
2013-01-01
This study shows that the Caspian Sea level time series possess long range dependence even after removing linear trends, based on analyses of the Hurst statistic, the sample autocorrelation functions, and the periodogram of the series. Forecasting performance of ARMA, ARIMA, ARFIMA and Trend Line-ARFIMA (TL-ARFIMA) combination models are investigated. The forecast confidence bands and the forecast updating methodology, provided for ARIMA models in the literature, are modified for the ARFIMA models. Sample autocorrelation functions are utilized to estimate the differencing lengths of the ARFIMA
Long-range correlations in high multiplicity and collisions
Indian Academy of Sciences (India)
Gunther Roland
2015-05-01
This review summarizes recent discoveries in high-energy proton+proton and proton+nucleus collisions, with particular attention on the observation of long-range azimuthal correlations in high multiplicity collisions. These correlations, which resemble those seen in ultrarelativistic nucleus–nucleus collisions, provide a unique window into the physics of the very early collision stage in high energy nuclear interactions. Here we present a compilation of the most important experimental results and briefly discuss successes and challenges for a selection of theoretical approaches.
Long-range correlations and coherent structures in magnetohydrodynamic equilibria.
Weichman, Peter B
2012-12-01
The equilibrium theory of the 2D magnetohydrodynamic equations is derived, accounting for the full infinite hierarchies of conserved integrals. An exact description in terms of two coupled elastic membranes emerges, producing long-ranged correlations between the magnetic and velocity fields. This is quite different from the results of previous variational treatments, which relied on a local product ansatz for the thermodynamic Gibbs distribution. The equilibria display the same type of coherent structures, such as compact eddies and zonal jets, previously found in pure fluid equilibria. Possible consequences of this for recent simulations of the solar tachocline are discussed.
Reconfigurable long-range phonon dynamics in optomechanical arrays
Xuereb, André; Pupillo, Guido; Paternostro, Mauro; Dantan, Aurélien
2013-01-01
We investigate periodic optomechanical arrays as reconfigurable platforms for engineering the coupling between multiple mechanical and electromagnetic modes and for exploring many-body phonon dynamics. Exploiting structural resonances in the coupling between light fields and collective motional modes of the array, we show that tunable effective long-range interactions between mechanical modes can be achieved. This paves the way towards the implementation of controlled phononic walks and heat transfer on densely-connected graphs as well as the coherent transfer of excitations between distant elements of optomechanical arrays.
Method of coupled mode for long-range bottom reverberation
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
The theory of coupled mode is used for modeling the long-range bottom reverberation in shallow water caused by bottom roughness. The distant bottom reverberation level and spatial coherence of impulsive source are both derived. The results agree with those from the classical reverberation model, and are compared with the experimental data. The influence of source bandwidth and the distance between sources and receivers on the intensity of bottom reverberation are particularly discussed. The method is shown to be available for both the monoand the bi-static cases.
Energy Technology Data Exchange (ETDEWEB)
Buckland, R.J.; Kenoyer, D.J.; LaBuy, S.A.
1995-09-01
This Long-Range Plan presents the Decontamination and Dismantlement (D&D) Program planning status for facilities at the Idaho National Engineering Laboratory (INEL). The plan provides a general description of the D&D Program objectives, management criteria, and policy; discusses current activities; and documents the INEL D&D Program cost and schedule estimate projections for the next 15 years. Appendices are included that provide INEL D&D project historical information, a comprehensive descriptive summary of each current D&D surplus facility, and a summary database of all INEL contaminated facilities awaiting or undergoing the facility transition process.
Long-range exchange interaction between magnetic impurities in graphene
Agarwal, M.; Mishchenko, E. G.
2017-02-01
The effective spin exchange RKKY coupling between impurities (adatoms) on graphene mediated by conduction electrons is studied as a function of the strength of the potential part of the on-site energy U of the electron-adatom interaction. With increasing U , the exchange coupling becomes long range, determined largely by the impurity levels with energies close to the Dirac points. When adatoms reside on opposite sublattices, their exchange coupling, normally antiferromagnetic, becomes ferromagnetic and resonantly enhanced at a specific distance where an impurity level crosses the Dirac point.
Sensitivity in the trajectory of long-range -particle
Indian Academy of Sciences (India)
P V Kunhikrishnan; A Rajan Nambiar; K P Santhosh
2012-09-01
The factors influencing the trajectory of long-range -particle in the cold ternary fission of 252Cf are discussed. The trajectory of the -particle is studied by considering the influence of the force on the -particle due to Coulomb and proximity potentials and is found to have sensitive dependence on the initial position and initial energy of the -particle. The sensitivity to initial conditions signifies the presence of deterministic chaos which is characterized by Lyapunov exponent (LE). The LE is calculated using Wolf’s algorithm and found positive which implies that the objectives of trajectory calculations are restricted.
Microbuckling in fibrin networks enables long-range cell mechanosensing
Notbohm, Jacob; Rosakis, Phoebus; Tirrell, David A; Ravichandran, Guruswami
2014-01-01
We show that cells in a fibrous matrix induce deformation fields that propagate over a longer range than predicted by linear elasticity. Synthetic, linear elastic hydrogels used in many mechanotrans- duction studies fail to capture this effect. We develop a nonlinear microstructural finite element model for a fiber network to simulate localized deformations induced by cells. The model captures measured cell-induced matrix displacements from experiments and identifies an important mech- anism for long range cell mechanosensing: loss of compression stiffness due to microbuckling of individual fibers. We show evidence that cells sense each other through the formation of localized intercellular bands of tensile deformations caused by this mechanism.
Long-range response in ac electricity grids
Jung, Daniel; Kettemann, Stefan
2016-07-01
Local changes in the topology of electricity grids can cause overloads far away from the disturbance [D. Witthaut and M. Timme, Eur. Phys. J. B 86, 377 (2013), 10.1140/epjb/e2013-40469-4], making the prediction of the robustness against changes in the topology—for example, caused by power outages or grid extensions—a challenging task. The impact of single-line additions on the long-range response of dc electricity grids has recently been studied [D. Labavić, R. Suciu, H. Meyer-Ortmanns, and S. Kettemann, Eur. Phys. J.: Spec. Top. 223, 2517 (2014), 10.1140/epjst/e2014-02273-0]. By solving the real part of the static ac load flow equations, we conduct a similar investigation for ac grids. In a regular two-dimensional grid graph with cyclic boundary conditions, we find a power law decay for the change of power flow as a function of distance to the disturbance over a wide range of distances. The power exponent increases and saturates for large system sizes. By applying the same analysis to the German transmission grid topology, we show that also in real-world topologies a long-ranged response can be found.
Phase transitions in simplified models with long-range interactions
Rocha Filho, T. M.; Amato, M. A.; Mello, B. A.; Figueiredo, A.
2011-10-01
We study the origin of phase transitions in several simplified models with long-range interactions. For the self-gravitating ring model, we are unable to observe a possible phase transition predicted by Nardini and Casetti [Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.80.060103 80, 060103R (2009).] from an energy landscape analysis. Instead we observe a sharp, although without any nonanalyticity, change from a core-halo to a core-only configuration in the spatial distribution functions for low energies. By introducing a different class of solvable simplified models without any critical points in the potential energy we show that a behavior similar to the thermodynamics of the ring model is obtained, with a first-order phase transition from an almost homogeneous high-energy phase to a clustered phase and the same core-halo to core configuration transition at lower energies. We discuss the origin of these features for the simplified models and show that the first-order phase transition comes from the maximization of the entropy of the system as a function of energy and an order parameter, as previously discussed by Hahn and Kastner [Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.72.056134 72, 056134 (2005); Eur. Phys. J. BEPJBFY1434-602810.1140/epjb/e2006-00100-7 50, 311 (2006)], which seems to be the main mechanism causing phase transitions in long-range interacting systems.
Disordered Kitaev chains with long-range pairing
Cai, Xiaoming
2017-03-01
We study the competition of disorder and superconductivity for a generalized Kitaev model in incommensurate potentials. The generalized Kitaev model describes one dimensional spinless fermions with long-range p-wave superconducting pairing, which decays with distance l as a power law ∼1/{{l}α} . We focus on the transition from the topological superconducting phase to the topologically trivial Anderson localized phase, and effects of the exponent α on this phase transition. In the topological superconducting phase, for a system under open boundary condition the amplitude of zero-mode Majorana fermion has a hybrid exponential-algebraic decay as the distance increases from the edge. In the Anderson localized phase, some single-particle states remain critical for very strong disorders and the number of critical states increases as α decreases. In addition, except for critical disorders, the correlation function always has an exponential decay at the short range and an algebraic decay at the long range. Phase transition points are also numerically determined and the topological phase transition happens earlier at a smaller disorder strength for a system with smaller α.
Long-range synchrony and emergence of neural reentry
Keren, Hanna; Marom, Shimon
2016-11-01
Neural synchronization across long distances is a functionally important phenomenon in health and disease. In order to access the basis of different modes of long-range synchrony, we monitor spiking activities over centimetre scale in cortical networks and show that the mode of synchrony depends upon a length scale, λ, which is the minimal path that activity should propagate through to find its point of origin ready for reactivation. When λ is larger than the physical dimension of the network, distant neuronal populations operate synchronously, giving rise to irregularly occurring network-wide events that last hundreds of milliseconds to several seconds. In contrast, when λ approaches the dimension of the network, a continuous self-sustained reentry propagation emerges, a regular seizure-like mode that is marked by precise spatiotemporal patterns (‘synfire chains’) and may last many minutes. Termination of a reentry phase is preceded by a decrease of propagation speed to a halt. Stimulation decreases both propagation speed and λ values, which modifies the synchrony mode respectively. The results contribute to the understanding of the origin and termination of different modes of neural synchrony as well as their long-range spatial patterns, while hopefully catering to manipulation of the phenomena in pathological conditions.
Short and Long Range Screening of Optical Singularities
Kessler, David A
2007-01-01
Screening of topological charges (singularities) is discussed for paraxial optical fields with short and with long range correlations. For short range screening the charge variance in a circular region with radius $R$ grows linearly with $R$, instead of with $R^{2}$ as expected in the absence of screening; for long range screening it grows faster than $R$: for a field whose autocorrelation function is the zero order Bessel function J_{0}, the charge variance grows as R ln R$. A J_{0} correlation function is not attainable in practice, but we show how to generate an optical field whose correlation function closely approximates this form. The charge variance can be measured by counting positive and negative singularities inside the region A, or more easily by counting signed zero crossings on the perimeter of A. \\For the first method the charge variance is calculated by integration over the charge correlation function C(r), for the second by integration over the zero crossing correlation function Gamma(r). Usin...
Surface tension and long range corrections of cylindrical interfaces
Energy Technology Data Exchange (ETDEWEB)
Bourasseau, E. [CEA/DAM DIF, F-91297 Arpajon Cedex (France); Malfreyt, P. [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand (France); Ghoufi, A., E-mail: aziz.ghoufi@univ-rennes1.fr [Institut de Physique de Rennes, UMR 6251 CNRS, Université de Rennes 1, 263 avenue Général Leclerc, 35042 Rennes (France)
2015-12-21
The calculation of the surface tension of curved interfaces has been deeply investigated from molecular simulation during this last past decade. Recently, the thermodynamic Test-Area (TA) approach has been extended to the calculation of surface tension of curved interfaces. In the case of the cylindrical vapour-liquid interfaces of water and Lennard-Jones fluids, it was shown that the surface tension was independent of the curvature of the interface. In addition, the surface tension of the cylindrical interface is higher than that of the planar interface. Molecular simulations of cylindrical interfaces have been so far performed (i) by using a shifted potential, (ii) by means of large cutoff without periodic boundary conditions, or (iii) by ignoring the long range corrections to the surface tension due to the difficulty to estimate them. Indeed, unlike the planar interfaces there are no available operational expressions to consider the tail corrections to the surface tension of cylindrical interfaces. We propose here to develop the long range corrections of the surface tension for cylindrical interfaces by using the non-exponential TA (TA2) method. We also extend the formulation of the Mecke-Winkelmann corrections initially developed for planar surfaces to cylindrical interfaces. We complete this study by the calculation of the surface tension of cylindrical surfaces of liquid tin and copper using the embedded atom model potentials.
On the Long-Range Directed Polymer Model
Wei, Ran
2016-10-01
We study the long-range directed polymer model on Z in a random environment, where the underlying random walk lies in the domain of attraction of an α -stable process for some α in (0,2]. Similar to the more classic nearest-neighbor directed polymer model, as the inverse temperature β increases, the model undergoes a transition from a weak disorder regime to a strong disorder regime. We extend most of the important results known for the nearest-neighbor directed polymer model on Z^d to the long-range model on Z. More precisely, we show that in the entire weak disorder regime, the polymer satisfies an analogue of invariance principle, while in the so-called very strong disorder regime, the polymer end point distribution contains macroscopic atoms and under some mild conditions, the polymer has a super-α -stable motion. Furthermore, for α in (1,2], we show that the model is in the very strong disorder regime whenever β >0, and we give explicit bounds on the free energy.
Long-range GABAergic connections distributed throughout the neocortex and their possible function
Directory of Open Access Journals (Sweden)
Nobuaki eTamamaki
2010-12-01
Full Text Available Features and functions of long range GABAergic projection neurons in the developing cerebral cortex have been reported previously, although until now their significance in the adult cerebral cortex has remained uncertain. The septo-hippocampal circuit is one exception – in this system, long range mature GABAergic projection neurons have been well analyzed and their contribution to the generation of theta-oscillatory behavior in the hippocampus has been documented. To have a clue to the function of the GABAergic projection neurons in the neocortex, we view the long range GABAergic projections those participating in the cortico-cortical, cortico-fugal, and afferent projections in the cerebral cortex. Then, we consider the possibility that the GABAergic projection neurons are involved in the generation, modification, and/or synchronization of oscillations in mature neocortical neuron activity. When markers that identify the GABAergic projection neurons are examined in anatomical and developmental studies, it is clear that neuronal NO synthetase (nNOS-immunoreactivity can readily identify GABAergic projection fibers (i.e. those longer than 1.5 mm. To elucidate the role of the GABAergic projection neurons in the neocortex, it will be necessary to clarify the network constructed by nNOS-positive GABAergic projection neurons and their postsynaptic targets. Thus, our long-range goals will be to label and manipulate (including deleting the GABAergic projection neurons using genetic tools driven by a nNOS promoter. We recognize that this may be a complex endeavor, as most excitatory neurons in the murine neocortex express nNOS transiently. Nevertheless, additional studies characterizing long range GABAergic projection neurons will have great value to the overall understanding of mature cortical function.
Reservoir shore development in long range terrestrial laser scanning monitoring.
Kaczmarek, Halina
2016-04-01
Shore zones of reservoirs are in most cases very active, getting transformed as a result of coastal processes and mass movements initiated on the slopes surrounding the reservoir. From the point of view of the users of water reservoirs shore recession strongly undesirable as it causes destruction to infrastructure and buildings located in the immediate vicinity of the reservoir. For this reason, reservoir shores require continuous geodetic monitoring. Fast and accurate geodetic measurements covering shore sections several kilometers long, often in poorly accessible areas, are available using long range terrestrial laser scanning (TLS). The possibilities of using long range terrestrial laser scanning are shown on the example of the reservoir Jeziorsko on the Warta River (Central Poland). This reservoir, created in the years 1986-1992, is a typical retention reservoir, the annual fluctuations of which reach 5 m. Depending on the water level its surface area ranges from 42.3 to 19.6 km2. The width of the reservoir is 2.5 km. The total shore length of the reservoir, developed in Quaternary till and sand-till sediments, is 44.3 km, including 30.1 km of the unreinforced shore. Out of the unreinforced shore 27% is subject to coastal erosion. The cliff heights vary from a few cm to 12.5 meters, and the current rate of the cliff recession ranges from 0 to 1.12 m/y. The study used a terrestrial long range laser scanner Riegl VZ-4000 of a range of up to 4000 m. It enabled conducting the measurements of the cliff recession from the opposite shore of the reservoir, with an angular resolution of 0.002°, which gives about 50 measurement points per 1 m2. The measurements were carried out in the years 2014-2015, twice a year, in early spring before high water level, and in late autumn at a dropping water level. This allowed the separation of the impact of coastal processes and frost weathering on the cliff recession and their quantitative determination. The size and nature of
Long-Range Lepton Flavor Interactions and Neutrino Oscillations
Energy Technology Data Exchange (ETDEWEB)
Davoudiasl, H.; Lee, H-S; Marciano, W.
2011-03-31
Recent results from the MINOS accelerator neutrino experiment suggest a possible difference between {nu}{sub {mu}} and {bar {nu}}{sub {mu}} disappearance oscillation parameters, which one may ascribe to a new long distance potential acting on neutrinos. As a specific example, we consider a model with gauged B - L{sub e} - 2L{sub {tau}} number which contains an extremely light new vector boson, m{sub Z}, < 10{sup -18} eV and extraordinarily weak coupling {alpha}{prime} {approx}< 10{sup -52}. In that case, differences between {nu}{sub {mu}} {yields} {nu}{sub {tau}} and {bar {nu}}{sub {mu}} {yields} {bar {nu}}{sub {tau}} oscillations can result from a long-range potential due to neutrons in the Earth and the Sun that distinguishes {nu}{sub {mu}} and {nu}{sub {tau}} on Earth, with a potential difference of {approx} 6 x 10{sup -14} eV, and changes sign for anti-neutrinos. We show that existing solar, reactor, accelerator, and atmospheric neutrino oscillation constraints can be largely accommodated for values of parameters that help explain the possible MINOS anomaly by this new physics, although there is some tension with atmospheric constraints. A long-range interaction, consistent with current bounds, could have very pronounced effects on atmospheric neutrino disappearance in the 20-50 GeV range that will be studied with the IceCube DeepCore array, currently in operation, and can have a significant effect on future high-precision long-baseline oscillation experiments which aim for {+-}1% sensitivity, in {nu}{sub {mu}} and {bar {nu}}{sub {mu}} disappearance, separately. Together, these experiments can extend the reach for new long-distance effects well beyond current bounds and test their relevance to the aforementioned MINOS anomaly. We also point out that long-range potentials originating from the Sun could lead to annual modulations of neutrino data at the percent level, due to the variation of the Earth-Sun distance. A similar phenomenology is shown to apply to
Phantom energy mediates a long-range repulsive force.
Amendola, Luca
2004-10-29
Scalar field models with nonstandard kinetic terms have been proposed in the context of k inflation, of Born-Infeld Lagrangians, of phantom energy and, more in general, of low-energy string theory. In general, scalar fields are expected to couple to matter inducing a new interaction. In this Letter I derive the cosmological perturbation equations and the Yukawa correction to gravity for such general models. I find three interesting results: first, when the field behaves as phantom energy (equation of state less than -1), then the coupling strength is negative, inducing a long-range repulsive force; second, the dark-energy field might cluster on astrophysical scales; third, applying the formalism to a Brans-Dicke theory with a general kinetic term it is shown that its Newtonian effects depend on a single parameter that generalizes the Brans-Dicke constant.
Long-range effects in electron scattering by polar molecules
Fabrikant, Ilya I.
2016-11-01
We review long-range effects in electron collisions with polar molecules, starting with elastic scattering. We then go to rotationally and vibrationally inelastic processes and dissociative electron attachment. The last two are strongly affected by vibrational Feshbach resonances which have been observed and described theoretically in many systems from simple diatomic molecules to more complex polyatomics, biologically relevant molecules, and van der Waals clusters. We then review environmental effects which include electron interaction with molecules adsorbed on surfaces and molecules in cluster environments. We concentrate on physics rather than on listing results of ab initio calculations. With increasing complexity of targets and processes model approaches become more relevant. We demonstrate their success in the theoretical description of electron attachment to polyatomic molecules and to molecules in complex environments.
On the origin of long-range correlations in texts.
Altmann, Eduardo G; Cristadoro, Giampaolo; Esposti, Mirko Degli
2012-07-17
The complexity of human interactions with social and natural phenomena is mirrored in the way we describe our experiences through natural language. In order to retain and convey such a high dimensional information, the statistical properties of our linguistic output has to be highly correlated in time. An example are the robust observations, still largely not understood, of correlations on arbitrary long scales in literary texts. In this paper we explain how long-range correlations flow from highly structured linguistic levels down to the building blocks of a text (words, letters, etc..). By combining calculations and data analysis we show that correlations take form of a bursty sequence of events once we approach the semantically relevant topics of the text. The mechanisms we identify are fairly general and can be equally applied to other hierarchical settings.
Traveling Solitons in Long-Range Oscillator Chains
Miloshevich, George; Dauxois, Thierry; Khomeriki, Ramaz; Ruffo, Stefano
2016-01-01
We investigate the existence and propagation of solitons in a long-range extension of the quartic Fermi-Pasta-Ulam (FPU) chain of anharmonic oscillators. The coupling in the linear term decays as a power-law with an exponent greater than 1 and less than 3. We obtain an analytic perturbative expression of traveling envelope solitons by introducing a Non Linear Schrodinger (NLS) equation for the slowly varying amplitude of short wavelength modes. Due to the non analytic properties of the dispersion relation, it is crucial to develop the theory using discrete difference operators. Those properties are also the ultimate reason why kink-solitons may exist but are unstable, at variance with the short-range FPU model. We successfully compare these approximate analytic results with numerical simulations.
On the origin of long-range correlations in texts
Altmann, Eduardo G; Esposti, Mirko Degli
2012-01-01
The complexity of human interactions with social and natural phenomena is mirrored in the way we describe our experiences through natural language. In order to retain and convey such a high dimensional information, the statistical properties of our linguistic output has to be highly correlated in time. An example are the robust observations, still largely not understood, of correlations on arbitrary long scales in literary texts. In this paper we explain how long-range correlations flow from highly structured linguistic levels down to the building blocks of a text (words, letters, etc..). By combining calculations and data analysis we show that correlations take form of a bursty sequence of events once we approach the semantically relevant topics of the text. The mechanisms we identify are fairly general and can be equally applied to other hierarchical settings.
Mechanism of long-range proton translocation along biological membranes.
Medvedev, Emile S; Stuchebrukhov, Alexei A
2013-02-14
Recent experiments suggest that protons can travel along biological membranes up to tens of micrometers, but the mechanism of transport is unknown. To explain such a long-range proton translocation we describe a model that takes into account the coupled bulk diffusion that accompanies the migration of protons on the surface. We show that protons diffusing at or near the surface before equilibrating with the bulk desorb and re-adsorb at the surface thousands of times, giving rise to a power-law desorption kinetics. As a result, the decay of the surface protons occurs very slowly, allowing for establishing local gradient and local exchange, as was envisioned in the early local models of biological energy transduction.
Kinetic Gaussian Model with Long-Range Interactions
Institute of Scientific and Technical Information of China (English)
KONGXiang-Mu; YANGZhan-Ru
2004-01-01
In this paper dynamical critical phenomena of the Gaussian model with long-range interactions decayingas 1/rd+δ (δ>0) on d-dimensional hypercubic lattices (d = 1, 2, and 3) are studied. First, the critical points are exactly calculated, and it is found that the critical points depend on the value of δ and the range of interactions. Then the critical dynamics is considered. We calculate the time evolutions of the local magnetizations and the spin-spin correlation functions, and further the dynamic critical exponents are obtained. For one-, two- and three-dimensional lattices, it is found that the dynamic critical exponents are all z = 2 if δ > 2, which agrees with the result when only considering nearest neighboring interactions, and that they are all δ if 0 < δ < 2. It shows that the dynamic critical exponents are independent of the spatial dimensionality but depend on the value of δ.
Kinetic Gaussian Model with Long-Range Interactions
Institute of Scientific and Technical Information of China (English)
KONG Xiang-Mu; YANG Zhan-Ru
2004-01-01
In this paper dynamical critical phenomena of the Gaussian model with long-range interactions decaying as 1/rd+δ (δ＞ 0) on d-dimensional hypercubic lattices (d = 1, 2, and 3) are studied. First, the critical points are exactly calculated, and it is found that the critical points depend on the value of δ and the range of interactions. Then the critical dynamics is considered. We calculate the time evolutions of the local magnetizations and the spin-spin correlation functions, and further the dynamic critical exponents are obtained. For one-, two- and three-dimensional lattices, it is found that the dynamic critical exponents are all z = 2 if δ＞ 2, which agrees with the result when only considering nearest neighboring interactions, and that they are all δ if 0 ＜δ＜ 2. It shows that the dynamic critical exponents are independent of the spatial dimensionality but depend on the value of δ.
Long range properties of $1S$-bottomonium states
Brambilla, Nora; Castellà, Jaume Tarrús; Vairo, Antonio
2015-01-01
We derive an analytical expression for the chromo-polarizability of $1S$-bottomonium states using weakly-coupled pNRQCD. In this setting the intermediate octet states have Coulombic continuum wavefunctions. We use the QCD trace anomaly to obtain the two-pion production amplitude for the chromo-polarizability operator and match the result to a Chiral Effective Field Theory (EFT) with $1S$-bottomonium states and pions as degrees-of-freedom. In this chiral EFT we compute long range properties of the $1S$-bottomonium generated by the pion coupling such as the leading chiral log to the $1S$-bottomonium mass and the van der Waals potential between two $1S$-bottomonium states.
Long range prediction of Indian summer monsoon rainfall
Indian Academy of Sciences (India)
A A Munot; K Krishna Kumar
2007-02-01
The search for new parameters for predicting the all India summer monsoon rainfall (AISMR) has been an important aspect of long range prediction of AISMR. In recent years NCEP/NCAR reanalysis has improved the geographical coverage and availability of the data and this can be easily updated. In this study using NCEP/NCAR reanalysis data on temperature, zonal and meridional wind at different pressure levels, few predictors are identified and a prediction scheme is developed for predicting AISMR. The regression coeffcients are computed by stepwise multiple regression procedure. The final equation explained 87% of the variance with multiple correlation coeffcient (MCC), 0.934. The estimated rainfall in the El-Nino year of 1997 was -1.7% as against actual of 4.4%. The estimated rainfall deficiency in both the recent deficient years of 2002 and 2004 were -19.5% and -8.5% as against observed -20.4% and -11.5% respectively.
An Autonomous Long Range Monitoring System For Emergency Operators
Lanati, Matteo; Secco, Emanuele Lindo; Magenes, Giovanni; Gamba, Paolo
2011-01-01
Miniaturization and portability of new electronics lead up to wearable devices embedded within garments: a European program called ProeTEX developed multi-purpose sensors integrated within emergency operators' garments in order to monitor their health state and the surrounding environment. This work deals with the development of an autonomous Long Range communication System (LRS), suitable to transmit data between operators' equipment and the local command post, where remote monitoring software is set up. The LRS infrastructure is based on Wi-Fi protocol and modular architecture. Field tests carried out on the developed prototype showed a high reliability in terms of correctly exchanged data and recovering capabilities in case of temporary disconnection, due to the operator's movements.
Long-Range Correlations in Small Atomic Clusters
Nayak, Saroj K.; Ramaswamy, R.
We study the power spectrum of fluctuations in the potential energy of atoms in small rare-gas clusters. At temperatures when the cluster is in a liquid-like state the spectra have a “1/f” dependence over a wide range of frequency f. This behavior is distinctly different from both the solid phase of clusters or bulk liquid, and is indicative of long-range temporal correlations. The origins of this phenomenon is explored by studying the individual potential-energy distributions in pure and mixed rare-gas clusters, Xe55 and ArXe54, via molecular dynamics simulations. Substitution of atomic impurities acts as an effective probe of the dynamics, and we observe that long-lived memory effects have their origins in hierarchical relaxation processes arising in the motion of the atoms from the surface to the core and vice-versa.
Vlasov equation for long-range interactions on a lattice
Bachelard, Romain; De Ninno, Giovanni; Ruffo, Stefano; Staniscia, F
2011-01-01
We show that, in the continuum limit, the dynamics of Hamiltonian systems defined on a lattice with long-range couplings is well described by the Vlasov equation. This equation can be linearized around the homogeneous state and a dispersion relation, that depends explicitly on the Fourier modes of the lattice, can be derived. This allows to compute the stability thresholds of the homogeneous state, which turn out to depend on the mode number. When this state is unstable, the growth rates are also function of the mode number. Explicit calculations are performed for the $\\alpha$-HMF model with $0 \\leq \\alpha <1$, for which the zero mean-field mode is always found to dominate the exponential growth. The theoretical predictions are successfully compared with numerical simulations performed on a finite lattice.
Vlasov equation for long-range interactions on a lattice.
Bachelard, R; Dauxois, T; De Ninno, G; Ruffo, S; Staniscia, F
2011-06-01
We show that, in the continuum limit, the dynamics of Hamiltonian systems defined on a lattice with long-range couplings is well described by the Vlasov equation. This equation can be linearized around the homogeneous state, and a dispersion relation, which depends explicitly on the Fourier modes of the lattice, can be derived. This allows one to compute the stability thresholds of the homogeneous state, which turns out to depend on the mode number. When this state is unstable, the growth rates are also functions of the mode number. Explicit calculations are performed for the α-Hamiltonian mean field model with 0≤α<1, for which the mean-field mode is always found to dominate the exponential growth. The theoretical predictions are successfully compared with numerical simulations performed on a finite lattice.
Formation of the long range Dpp morphogen gradient.
Directory of Open Access Journals (Sweden)
Gerald Schwank
2011-07-01
Full Text Available The TGF-β homolog Decapentaplegic (Dpp acts as a secreted morphogen in the Drosophila wing disc, and spreads through the target tissue in order to form a long range concentration gradient. Despite extensive studies, the mechanism by which the Dpp gradient is formed remains controversial. Two opposing mechanisms have been proposed: receptor-mediated transcytosis (RMT and restricted extracellular diffusion (RED. In these scenarios the receptor for Dpp plays different roles. In the RMT model it is essential for endocytosis, re-secretion, and thus transport of Dpp, whereas in the RED model it merely modulates Dpp distribution by binding it at the cell surface for internalization and subsequent degradation. Here we analyzed the effect of receptor mutant clones on the Dpp profile in quantitative mathematical models representing transport by either RMT or RED. We then, using novel genetic tools, experimentally monitored the actual Dpp gradient in wing discs containing receptor gain-of-function and loss-of-function clones. Gain-of-function clones reveal that Dpp binds in vivo strongly to the type I receptor Thick veins, but not to the type II receptor Punt. Importantly, results with the loss-of-function clones then refute the RMT model for Dpp gradient formation, while supporting the RED model in which the majority of Dpp is not bound to Thick veins. Together our results show that receptor-mediated transcytosis cannot account for Dpp gradient formation, and support restricted extracellular diffusion as the main mechanism for Dpp dispersal. The properties of this mechanism, in which only a minority of Dpp is receptor-bound, may facilitate long-range distribution.
Incoherent shock waves in long-range optical turbulence
Xu, G.; Garnier, J.; Faccio, D.; Trillo, S.; Picozzi, A.
2016-10-01
Considering the nonlinear Schrödinger (NLS) equation as a representative model, we report a unified presentation of different forms of incoherent shock waves that emerge in the long-range interaction regime of a turbulent optical wave system. These incoherent singularities can develop either in the temporal domain through a highly noninstantaneous nonlinear response, or in the spatial domain through a highly nonlocal nonlinearity. In the temporal domain, genuine dispersive shock waves (DSW) develop in the spectral dynamics of the random waves, despite the fact that the causality condition inherent to the response function breaks the Hamiltonian structure of the NLS equation. Such spectral incoherent DSWs are described in detail by a family of singular integro-differential kinetic equations, e.g. Benjamin-Ono equation, which are derived from a nonequilibrium kinetic formulation based on the weak Langmuir turbulence equation. In the spatial domain, the system is shown to exhibit a large scale global collective behavior, so that it is the fluctuating field as a whole that develops a singularity, which is inherently an incoherent object made of random waves. Despite the Hamiltonian structure of the NLS equation, the regularization of such a collective incoherent shock does not require the formation of a DSW - the regularization is shown to occur by means of a different process of coherence degradation at the shock point. We show that the collective incoherent shock is responsible for an original mechanism of spontaneous nucleation of a phase-space hole in the spectrogram dynamics. The robustness of such a phase-space hole is interpreted in the light of incoherent dark soliton states, whose different exact solutions are derived in the framework of the long-range Vlasov formalism.
Gander, Philippa H; Signal, T Leigh; van den Berg, Margo J; Mulrine, Hannah M; Jay, Sarah M; Jim Mangie, Captain
2013-12-01
This study evaluated whether pilot fatigue was greater on ultra-long range (ULR) trips (flights >16 h on 10% of trips in a 90-day period) than on long range (LR) trips. The within-subjects design controlled for crew complement, pattern of in-flight breaks, flight direction and departure time. Thirty male Captains (mean age = 54.5 years) and 40 male First officers (mean age = 48.0 years) were monitored on commercial passenger flights (Boeing 777 aircraft). Sleep was monitored (actigraphy, duty/sleep diaries) from 3 days before the first study trip to 3 days after the second study trip. Karolinska Sleepiness Scale, Samn-Perelli fatigue ratings and a 5-min Psychomotor Vigilance Task were completed before, during and after every flight. Total sleep in the 24 h before outbound flights and before inbound flights after 2-day layovers was comparable for ULR and LR flights. All pilots slept on all flights. For each additional hour of flight time, they obtained an estimated additional 12.3 min of sleep. Estimated mean total sleep was longer on ULR flights (3 h 53 min) than LR flights (3 h 15 min; P(F) = 0.0004). Sleepiness ratings were lower and mean reaction speed was faster at the end of ULR flights. Findings suggest that additional in-flight sleep mitigated fatigue effectively on longer flights. Further research is needed to clarify the contributions to fatigue of in-flight sleep versus time awake at top of descent. The study design was limited to eastward outbound flights with two Captains and two First Officers. Caution must be exercised when extrapolating to different operations.
Classical investigation of long-range coherence in biological systems
Preto, Jordane
2016-12-01
Almost five decades ago, H. Fröhlich [H. Fröhlich, "Long-range coherence and energy storage in biological systems," Int. J. Quantum Chem. 2(5), 641-649 (1968)] reported, on a theoretical basis, that the excitation of quantum modes of vibration in contact with a thermal reservoir may lead to steady states, where under high enough rate of energy supply, only specific low-frequency modes of vibration are strongly excited. This nonlinear phenomenon was predicted to occur in biomolecular systems, which are known to exhibit complex vibrational spectral properties, especially in the terahertz frequency domain. However, since the effects of terahertz or lower-frequency modes are mainly classical at physiological temperatures, there are serious doubts that Fröhlich's quantum description can be applied to predict such a coherent behavior in a biological environment, as suggested by the author. In addition, a quantum formalism makes the phenomenon hard to investigate using realistic molecular dynamics simulations (MD) as they are usually based on the classical principles. In the current paper, we provide a general classical Hamiltonian description of a nonlinear open system composed of many degrees of freedom (biomolecular structure) excited by an external energy source. It is shown that a coherent behaviour similar to Fröhlich's effect is to be expected in the classical case for a given range of parameter values. Thus, the supplied energy is not completely thermalized but stored in a highly ordered fashion. The connection between our Hamiltonian description, carried out in the space of normal modes, and a more standard treatment in the physical space is emphasized in order to facilitate the prediction of the effect from MD simulations. It is shown how such a coherent phenomenon may induce long-range resonance effects that could be of critical importance at the biomolecular level. The present work is motivated by recent experimental evidences of long-lived excited low
Ultracold Long-Range Rydberg Molecules with Complex Multichannel Spectra
Eiles, Matthew; Greene, Chris
2016-05-01
A generalized class of exotic long-range Rydberg molecules consisting of a multichannel Rydberg atom bound to a distant ground state atom by the Rydberg electron is predicted. These molecules are characterized by the rich physics provided by the strongly perturbed multichannel Rydberg spectra of divalent atoms, in contrast to the regular Rydberg series of the alkali atoms used to form Rydberg molecules to date. These multichannel Rydberg molecules exhibit favorable properties for laser excitation, because states exist where the quantum defect varies strongly with the principal quantum number n. In particular, the nd Rydberg state of calcium becomes nearly degenerate with states of high orbital angular momentum over the range 17 molecular states are predicted to occur in the low- J states of silicon, which are strongly perturbed due to channel interactions between Rydberg series leading to the spin-orbit split ionization thresholds. These interactions manifest themselves in potential curves exhibiting two distinct length scales, providing novel opportunities for quantum manipulation. Supported in part by the National Science Foundation under Grant No. PHY-1306905.
Long-range correlations and the momentum distribution in nuclei
Amir-Azimi-Nili, K; Skouras, L D; Polls, A
1996-01-01
The influence of correlations on the momentum distribution of nucleons in nuclei is evaluated starting from a realistic nucleon-nucleon interaction. The calculations are performed directly for the finite nucleus \\,^{16}O making use of the Green's function approach. The emphasis is focused on the correlations induced by the excitation modes at low energies described within a model-space of shell-model configurations including states up to the sdg shell. Our analysis demonstrates that these long-range correlations do not produce any significant enhancement of the momentum distribution at high missing momenta and low missing energies. This is in agreement with high resolution (e,e'p) experiments for this nucleus. We also try to simulate the corresponding effects in large nuclei by quenching the energy-spacing between single-particle orbits. This yields a sizable enhancement of the spectral function at large momenta and small energy. Such behavior could explain the deviation of the momentum distribution from the ...
Long-range interacting systems in the unconstrained ensemble.
Latella, Ivan; Pérez-Madrid, Agustín; Campa, Alessandro; Casetti, Lapo; Ruffo, Stefano
2017-01-01
Completely open systems can exchange heat, work, and matter with the environment. While energy, volume, and number of particles fluctuate under completely open conditions, the equilibrium states of the system, if they exist, can be specified using the temperature, pressure, and chemical potential as control parameters. The unconstrained ensemble is the statistical ensemble describing completely open systems and the replica energy is the appropriate free energy for these control parameters from which the thermodynamics must be derived. It turns out that macroscopic systems with short-range interactions cannot attain equilibrium configurations in the unconstrained ensemble, since temperature, pressure, and chemical potential cannot be taken as a set of independent variables in this case. In contrast, we show that systems with long-range interactions can reach states of thermodynamic equilibrium in the unconstrained ensemble. To illustrate this fact, we consider a modification of the Thirring model and compare the unconstrained ensemble with the canonical and grand-canonical ones: The more the ensemble is constrained by fixing the volume or number of particles, the larger the space of parameters defining the equilibrium configurations.
Biases and caustics in long-range acoustic tomography
Munk, Walter; Wunsch, Carl
1985-11-01
We consider the travel time perturbation δt of acoustic rays in an ocean sound channel. The perturbations arom a straining e(x,z) of the water column. An expansion to second order gives δt ≈ τ + ατ , where and are suitably weighted strain wverages, α is a number of order 1 (except near caustics), and τ is the phase integral (the 'reduced travel time' in the seismic literature); τ is a function of ray steepness and range, and varies from zero for axial rays to order 10 s for steep rays at 1000 km range. The quadratic bais ατ changes sign at the caustics; generally it is negative (warm bias) for a range-dependent ocean as compared to a range-independent ocean with the same average properties. We consider two separate problems: (a) linear inversions for the range-averaged profile in soundspeed (temperature) introduces 0.5 m s -1 (0.1 °C) systematic errors arising from horizontal ocean variability (mesoscal activity), but these errors can be reduced by making corrections for . (b) In the problem of monitoring for climatic changes of large-scale ocean features, the quadratic bias is negligible compared to the sample variability, and there is an inherent advantage to the long-range horizontal integration in acoustic tomography over the traditional local measurements.
ORNL long-range environmental and waste management plan
Energy Technology Data Exchange (ETDEWEB)
Baldwin, J.S.; Bates, L.D.; Brown, C.H.; Easterday, C.A.; Hill, L.G.; Kendrick, C.M.; McNeese, L.E.; Myrick, T.E.; Payne, T.L.; Pepper, C.E.; Robinson, S.M.; Rohwer, P.S.; Scanlan, T.F.; Smith, M.A.; Stratton, L.E.; Trabalka, J.R.
1989-09-01
This report, the ORNL Long-Range Environmental and Waste Management Plan, is the annual update in a series begun in fiscal year 1985. Its primary purpose is to provide a thorough and systematic planning document to reflect the continuing process of site assessment, strategy development, and planning for the current and long-term control of environmental issues, waste management practices, and remedial action requirements. The document also provides an estimate of the resources required to implement the current plan. This document is not intended to be a budget document; it is, however, intended to provide guidance to both Martin Marietta Energy Systems, Inc., and the US Department of Energy (DOE) management as to the near order of magnitude of the resources (primarily funding requirements) and the time frame required to execute the strategy in the present revision of the plan. As with any document of this nature, the near-term (one to three years) part of the plan is a pragmatic assessment of the current program and ongoing capital projects and reflects the efforts perceived to be necessary to comply with all current state and federal regulations and DOE orders. It also should be in general agreement with current budget (funding) requests and obligations for these immediate years. 55 figs., 72 tabs.
Long-range interacting systems in the unconstrained ensemble
Latella, Ivan; Pérez-Madrid, Agustín; Campa, Alessandro; Casetti, Lapo; Ruffo, Stefano
2017-01-01
Completely open systems can exchange heat, work, and matter with the environment. While energy, volume, and number of particles fluctuate under completely open conditions, the equilibrium states of the system, if they exist, can be specified using the temperature, pressure, and chemical potential as control parameters. The unconstrained ensemble is the statistical ensemble describing completely open systems and the replica energy is the appropriate free energy for these control parameters from which the thermodynamics must be derived. It turns out that macroscopic systems with short-range interactions cannot attain equilibrium configurations in the unconstrained ensemble, since temperature, pressure, and chemical potential cannot be taken as a set of independent variables in this case. In contrast, we show that systems with long-range interactions can reach states of thermodynamic equilibrium in the unconstrained ensemble. To illustrate this fact, we consider a modification of the Thirring model and compare the unconstrained ensemble with the canonical and grand-canonical ones: The more the ensemble is constrained by fixing the volume or number of particles, the larger the space of parameters defining the equilibrium configurations.
Record length requirement of long-range dependent teletraffic
Li, Ming
2017-04-01
This article contributes the highlights mainly in two folds. On the one hand, it presents a formula to compute the upper bound of the variance of the correlation periodogram measurement of teletraffic (traffic for short) with long-range dependence (LRD) for a given record length T and a given value of the Hurst parameter H (Theorems 1 and 2). On the other hand, it proposes two formulas for the computation of the variance upper bound of the correlation periodogram measurement of traffic of fractional Gaussian noise (fGn) type and the generalized Cauchy (GC) type, respectively (Corollaries 1 and 2). They may constitute a reference guideline of record length requirement of traffic with LRD. In addition, record length requirement for the correlation periodogram measurement of traffic with either the Schuster type or the Bartlett one is studied and the present results about it show that both types of periodograms may be used for the correlation measurement of traffic with a pre-desired variance bound of correlation estimation. Moreover, real traffic in the Internet Archive by the Special Interest Group on Data Communication under the Association for Computing Machinery of US (ACM SIGCOMM) is analyzed in the case study in this topic.
Long-range spin Seebeck effect and acoustic spin pumping.
Uchida, K; Adachi, H; An, T; Ota, T; Toda, M; Hillebrands, B; Maekawa, S; Saitoh, E
2011-10-01
Imagine that a metallic wire is attached to a part of a large insulator, which itself exhibits no magnetization. It seems impossible for electrons in the wire to register where the wire is positioned on the insulator. Here we found that, using a Ni₈₁Fe₁₉/Pt bilayer wire on an insulating sapphire plate, electrons in the wire recognize their position on the sapphire. Under a temperature gradient in the sapphire, surprisingly, the voltage generated in the Pt layer is shown to reflect the wire position, although the wire is isolated both electrically and magnetically. This non-local voltage is due to the coupling of spins and phonons: the only possible carrier of information in this system. We demonstrate this coupling by directly injecting sound waves, which realizes the acoustic spin pumping. Our finding provides a persuasive answer to the long-range nature of the spin Seebeck effect, and it opens the door to 'acoustic spintronics' in which sound waves are exploited for constructing spin-based devices.
Experimental perspectives for systems based on long-range interactions
Bachelard, Romain; De Buyl, Pierre; Staniscia, F; Cataliotti, F S; De Ninno, G; Fanelli, Duccio; Piovella, Nicola
2010-01-01
The possibility of observing phenomena peculiar to long-range interactions, and more specifically in the so-called Quasi-Stationary State (QSS) regime is investigated within the framework of two devices, namely the Free-Electron Laser (FEL) and the Collective Atomic Recoil Laser (CARL). The QSS dynamics has been mostly studied using the Hamiltonian Mean-Field (HMF) toy model, demonstrating in particular the presence of first versus second order phase transitions from magnetized to unmagnetized regimes in the case of HMF. Here, we give evidence of the strong connections between the HMF model and the dynamics of the two mentioned devices, and we discuss the perspectives to observe some specific QSS features experimentally. In particular, a dynamical analog of the phase transition is present in the FEL and in the CARL in its conservative regime. Regarding the dissipative CARL, a formal link is established with the HMF model. For both FEL and CARL, calculations are performed with reference to existing experimenta...
A new smoothing function to introduce long-range electrostatic effects in QM/MM calculations
Energy Technology Data Exchange (ETDEWEB)
Fang, Dong [Department of Chemistry, Wayne State University, Detroit, Michigan 48202 (United States); Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706 (United States); Duke, Robert E.; Andrés Cisneros, G., E-mail: andres@chem.wayne.edu [Department of Chemistry, Wayne State University, Detroit, Michigan 48202 (United States)
2015-07-28
A new method to account for long range electrostatic contributions is proposed and implemented for quantum mechanics/molecular mechanics long range electrostatic correction (QM/MM-LREC) calculations. This method involves the use of the minimum image convention under periodic boundary conditions and a new smoothing function for energies and forces at the cutoff boundary for the Coulomb interactions. Compared to conventional QM/MM calculations without long-range electrostatic corrections, the new method effectively includes effects on the MM environment in the primary image from its replicas in the neighborhood. QM/MM-LREC offers three useful features including the avoidance of calculations in reciprocal space (k-space), with the concomitant avoidance of having to reproduce (analytically or approximately) the QM charge density in k-space, and the straightforward availability of analytical Hessians. The new method is tested and compared with results from smooth particle mesh Ewald (PME) for three systems including a box of neat water, a double proton transfer reaction, and the geometry optimization of the critical point structures for the rate limiting step of the DNA dealkylase AlkB. As with other smoothing or shifting functions, relatively large cutoffs are necessary to achieve comparable accuracy with PME. For the double-proton transfer reaction, the use of a 22 Å cutoff shows a close reaction energy profile and geometries of stationary structures with QM/MM-LREC compared to conventional QM/MM with no truncation. Geometry optimization of stationary structures for the hydrogen abstraction step by AlkB shows some differences between QM/MM-LREC and the conventional QM/MM. These differences underscore the necessity of the inclusion of the long-range electrostatic contribution.
Institute of Scientific and Technical Information of China (English)
尹晓林; 林万华; 方素萍; 陈希玲; 张天郎; 罗瑞贵; 李静; 吴志奎; 张新华
2012-01-01
目的 探讨重型β地中海贫血患者( thalassemia major,TM)BCL11A表达特点及其与临床表现的关系.方法 正常人和TM患者各24例,分离外周血单个核细胞,实时荧光定量聚合酶链反应(quantitative real time polymerase chain reaction,qRT-PCR)法检测BCL11A、γ基因mRNA表达水平,同时检测血常规血红蛋白(hemoglobin,Hb)、血红蛋白分析仪检测胎儿血红蛋白(fetal hemoglobin,HbF),并行相关性检验.结果 TM患者的HbF、γmRNA水平显著高于正常人群(13.7％±13.6％ vs 0.28％±0.15％,P＜0.001；2479％±279％ vs 10.61％±0.41％,P＜0.001),2组BCL11A基因mRNA水平无统计学差异(0.73％±0.26％ vs 0.77％±0.22％,P=0.590).TM患者中25％(6例)的患者HbF正常,与HbF升高者比较,其γmRNA水平要低(62.10％±16.49％vs 3285.2％±2792.2％,P＜0.001),但BCL11A mRNA水平无统计学差异(0.78％±0.21％ vs 0.72％±(0.28％,P=0.704).TM患者BCL11A mRNA水平与首次输血年龄无显著相关(r=0.201,P=0.345).结论 BCL11A不参与TM患者的γ基因的开放和HbF代偿性增加.%Objective To investigate the expression of BCL11A in patients with thalassemia major (TM) and its correlation with clinic manifestation. Methods Peripheral blood mononuclear cells were separated from 24 TM patients and 24 normal persons, BCL11A and γ mRNA expression was determined by quantitative real time polymerase chain reaction (qRT-PCR). Hemoglobin level and HbF percentage were detected by blood routine analysis and hemoglobin analysis. Results Compared with normal control, HbF level and y mRNA level in TM patients were increased significantly (HbF; 13. 7% ± 13.6% vs0.28%±0. 15%.P<0.001, y mRNA:2479% ± 279% vs 10.61% ± 0. 41 %, P<0.001). BCLllA mRNA level was not significantly different between two groups (0. 73% ± 0. 26% us (). 77% ± 0. 22%, P = 0. 590). Six TM patients (25%) had normal HbF levels. Compared with patients having increased HbF levels, patients with normal HbF levels had
Multifractal Geophysical Extremes: Nonstationarity and Long Range Correlations
Tchiguirinskaia, I.; Schertzer, D.; Lovejoy, S.
2012-04-01
Throughout the world, extremes in environmental sciences are of prime importance. They are key variables not only for risk assessments and engineering designs (e.g. of dams and bridges), but also for resource management (e.g. water and energy) and for land use. A better understanding of them is more and more indispensable in settling the debate on their possible climatological evolution. Whereas it took decades before a uniform technique for estimating flow frequencies within a stationary framework, it is often claimed that « stationarity is dead ! ». The fact that geophysical and environmental fields are variable over a wider range of scales than previously thought require to go beyond the limits of the (classical) Extreme Value Theory (EVT). Indeed, long-range correlations are beyond the scope of the classical EVT theory. We show that multifractal concepts and techniques are particularly appealing because they can effectively deal with a cascade of interactions concentrating for instance energy, liquid water, etc. into smaller and smaller space-time domains. Furthermore, a general outcome of these cascade processes -which surprisingly was realized only rather recently- is that rather independently of their details they yield probability distributions with power-law fall-offs, often called (asymptotic) Pareto or Zipf laws. We discuss the corresponding probability distributions of their maxima and its relationship with the Frechet law. We use these multifractal techniques to investigate the possibility of using very short or incomplete data records for reliable statistical predictions of the extremes. In particular we assess the multifractal parameter uncertainty with the help of long synthetic multifractal series and their sub-samples, in particular to obtain an approximation of confidence intervals that would be particularly important for the predictions of multifractal extremes. We finally illustrate the efficiency of this approach with its application to
Long-range transport of air pollution into the Arctic
Stohl, A.; Berg, T.; Breivik, K.; Burkhart, J. F.; Eckhardt, S.; Fjæraa, A.; Forster, C.; Herber, A.; Lunder, C.; McMillan, W. W.; None, N.; Manø, S.; Oltmans, S.; Shiobara, M.; Stebel, K.; Hirdman, D.; Stroem, J.; Tørseth, K.; Treffeisen, R.; Virkkunen, K.; Yttri, K. E.; Andrews, E.; Kowal, D.; Mefford, T.; Ogren, J. A.; Sharma, S.; Spichtinger, N.; Stone, R.; Hoch, S.; Wehrli, C.
2007-12-01
This paper presents an overview of air pollution transport into the Arctic. The major transport processes will be highlighted, as well as their seasonal, interannual, and spatial variability. The source regions of Arctic air pollution will be discussed, with a focus on black carbon (BC) sources, as BC can produce significant radiative forcing in the Arctic. It is found that Europe is the main source region for BC in winter, whereas boreal forest fires are the strongest source in summer, especially in years of strong burning. Two case studies of recent extreme Arctic air pollution events will be presented. In summer 2004, boreal forest fires in Alaska and Canada caused pan-Arctic enhancements of black carbon. The BC concentrations measured at Barrow (Alaska), Alert (Canada), Summit (Greenland) and Zeppelin (Spitsbergen) were all episodically elevated, as a result of the long-range transport of the biomass burning emissions. Aerosol optical depth was also episodically elevated at these stations, with an almost continuous elevation over more than a month at Summit. During the second episode in spring 2006, new records were set for all measured air pollutant species at the Zeppelin station (Spitsbergen) as well as for ozone in Iceland. At Zeppelin, BC, AOD, aerosol mass, ozone, carbon monoxide and other compounds all reached new record levels, compared to the long-term monitoring record. The episode was caused by transport of polluted air masses from Eastern Europe deep into the Arctic, a consequence of the unusual warmth in the European Arctic during the episode. While fossil fuel combustion sources certainly contributed to this episode, smoke from agricultural fires in Eastern Europe was the dominant pollution component. We also suggest a new revolatilization mechanism for persistent organic pollutants (POPs) stored in soils and vegetation by fires, as POPs were strongly elevated during both episodes. All this suggests a considerable influence of biomass burning on
2006 Long Range Development Plan Final Environmental ImpactReport
Energy Technology Data Exchange (ETDEWEB)
Philliber, Jeff
2007-01-22
This environmental impact report (EIR) has been prepared pursuant to the applicable provisions of the California Environmental Quality Act (CEQA) and its implementing guidelines (CEQA Guidelines), and the Amended University of California Procedures for Implementation of the California Environmental Quality Act (UC CEQA Procedures). The University of California (UC or the University) is the lead agency for this EIR, which examines the overall effects of implementation of the proposed 2006 Long Range Development Plan (LRDP; also referred to herein as the 'project' for purposes of CEQA) for Lawrence Berkeley National Laboratory (LBNL; also referred to as 'Berkeley Lab,' 'the Laboratory,' or 'the Lab' in this document). An LRDP is a land use plan that guides overall development of a site. The Lab serves as a special research campus operated by the University employees, but it is owned and financed by the federal government and as such it is distinct from the UC-owned Berkeley Campus. As a campus operated by the University of California, the Laboratory is required to prepare an EIR for an LRDP when one is prepared or updated pursuant to Public Resources Code Section 21080.09. The adoption of an LRDP does not constitute a commitment to, or final decision to implement, any specific project, construction schedule, or funding priority. Rather, the proposed 2006 LRDP describes an entire development program of approximately 980,000 gross square feet of new research and support space construction and 320,000 gross square feet of demolition of existing facilities, for a total of approximately 660,000 gross square feet of net new occupiable space for the site through 2025. Specific projects will undergo CEQA review at the time proposed to determine what, if any, additional review is necessary prior to approval. As described in Section 1.4.2, below, and in Chapter 3 of this EIR (the Project Description), the size of the project has been
Long-range correlation of the membrane potential in neocortical neurons during slow oscillation
Volgushev, Maxim; Chauvette, Sylvain; Timofeev, Igor
2012-01-01
Large amplitude slow waves are characteristic for the summary brain activity, recorded as electroencephalogram (EEG) or local field potentials (LFP), during deep stages of sleep and some types of anesthesia. Slow rhythm of the synchronized EEG reflects an alternation of active (depolarized, UP) and silent (hyperpolarized, DOWN) states of neocortical neurons. In neurons, involvement in the generalized slow oscillation results in a long-range synchronization of changes of their membrane potential as well as their firing. Here, we aimed at intracellular analysis of details of this synchronization. We asked which components of neuronal activity exhibit long-range correlations during the synchronized EEG? To answer this question, we made simultaneous intracellular recordings from two to four neocortical neurons in cat neocortex. We studied how correlated is the occurrence of active and silent states, and how correlated are fluctuations of the membrane potential in pairs of neurons located close one to the other or separated by up to 13 mm. We show that strong long-range correlation of the membrane potential was observed only (i) during the slow oscillation but not during periods without the oscillation, (ii) during periods which included transitions between the states but not during within-the-state periods, and (iii) for the low-frequency (10 Hz). In contrast to the neurons located several millimeters one from the other, membrane potential fluctuations in neighboring neurons remain strongly correlated during periods without slow oscillation. We conclude that membrane potential correlation in distant neurons is brought about by synchronous transitions between the states, while activity within the states is largely uncorrelated. The lack of the generalized fine-scale synchronization of membrane potential changes in neurons during the active states of slow oscillation may allow individual neurons to selectively engage in short living episodes of correlated activity
Lifetimes of ultra-long-range strontium Rydberg molecules
Camargo, F; Ding, R; Sadeghpour, H R; Yoshida, S; Burgdörfer, J; Dunning, F B; Killian, T C
2015-01-01
The lifetimes of the lower-lying vibrational states of ultralong-range strontium Rydberg molecules comprising one ground-state 5s2 1S0 atom and one Rydberg atom in the 5s38s 3S1 state are reported. The molecules are created in an ultracold gas held in an optical dipole trap and their numbers determined using ?eld ionization, the product electrons being detected by a microchannel plate. The measurements show that, in marked contrast to earlier measurements involving rubidium Rydberg molecules, the lifetimes of the low-lying molecular vibrational states are very similar to those of the parent Rydberg atoms. This results because the strong p-wave resonance in low-energy electronrubidium scattering, which plays an important role in determining the molecular lifetimes, is not present for strontium. The absence of this resonance o?ers advantages for experiments involving strontium Rydberg atoms as impurities in quantum gases and for testing theories of molecular formation and decay.
Stabilization of stationary excitation pulses in an open flow without long-range inhibition.
Kaern, Mads; Menzinger, Michael
2002-04-01
We study numerically and experimentally the stabilization of stationary excitation pulses in an open flow system. Since all the species have equal flow and diffusion coefficients, stabilization of stationary pulses by long-range inhibition is excluded. Upstream propagating pulses slow down as they approach the inflow boundary, where a constant forcing establishes a downstream extending subexcitable boundary layer. When the flow velocity is low, successive pulses vanish as they reach the subexcitable region. When the flow velocity is increased, the incoming pulses pile up near the inflow one after the other to form a stationary and space-periodic structure. This occurs in such a manner that the system remembers and stores the number of incoming pulses. We show that flow-induced stabilization of stationary pulses involves a mechanism by which the upstream subexcitable region and the flow cause the arrest of the pulse front and the pulse back, respectively. We discuss how the flow-stabilized structures compare to, and are different from those stabilized by a long-ranged, diffusive inhibition and from those observed in boundary-forced open flows of media showing relaxation-type oscillations.
Reduced long-range functional connectivity in young children with autism spectrum disorder
Yoshimura, Yuko; Hiraishi, Hirotoshi; Munesue, Toshio; Hashimoto, Takanori; Tsubokawa, Tsunehisa; Takahashi, Tsutomu; Suzuki, Michio; Higashida, Haruhiro; Minabe, Yoshio
2015-01-01
Autism spectrum disorder (ASD) is often described as a disorder of aberrant neural connectivity. Although it is important to study the pathophysiology of ASD in the developing cortex, the functional connectivity in the brains of young children with ASD has not been well studied. In this study, brain activity was measured non-invasively during consciousness in 50 young human children with ASD and 50 age- and gender-matched typically developing human (TD) children. We employed a custom child-sized magnetoencephalography (MEG) system in which sensors were located as close to the brain as possible for optimal recording in young children. We focused on theta band oscillations because they are thought to be involved in long-range networks associated with higher cognitive processes. The ASD group showed significantly reduced connectivity between the left-anterior and the right-posterior areas, exhibiting a decrease in the coherence of theta band (6 Hz) oscillations compared with the TD group. This reduction in coherence was significantly correlated with clinical severity in right-handed children with ASD. This is the first study to demonstrate reduced long-range functional connectivity in conscious young children with ASD using a novel MEG approach. PMID:24652855
Mapping the Shh long-range regulatory domain.
Anderson, Eve; Devenney, Paul S; Hill, Robert E; Lettice, Laura A
2014-10-01
Coordinated gene expression controlled by long-distance enhancers is orchestrated by DNA regulatory sequences involving transcription factors and layers of control mechanisms. The Shh gene and well-established regulators are an example of genomic composition in which enhancers reside in a large desert extending into neighbouring genes to control the spatiotemporal pattern of expression. Exploiting the local hopping activity of the Sleeping Beauty transposon, the lacZ reporter gene was dispersed throughout the Shh region to systematically map the genomic features responsible for expression activity. We found that enhancer activities are retained inside a genomic region that corresponds to the topological associated domain (TAD) defined by Hi-C. This domain of approximately 900 kb is in an open conformation over its length and is generally susceptible to all Shh enhancers. Similar to the distal enhancers, an enhancer residing within the Shh second intron activates the reporter gene located at distances of hundreds of kilobases away, suggesting that both proximal and distal enhancers have the capacity to survey the Shh topological domain to recognise potential promoters. The widely expressed Rnf32 gene lying within the Shh domain evades enhancer activities by a process that may be common among other housekeeping genes that reside in large regulatory domains. Finally, the boundaries of the Shh TAD do not represent the absolute expression limits of enhancer activity, as expression activity is lost stepwise at a number of genomic positions at the verges of these domains.
Long-range interactions of excited He atoms with ground-state noble-gas atoms
Zhang, J.-Y.
2013-10-09
The dispersion coefficients C6, C8, and C10 for long-range interactions of He(n1,3S) and He(n1,3P), 2≤n≤10, with the ground-state noble-gas atoms Ne, Ar, Kr, and Xe are calculated by summing over the reduced matrix elements of multipole transition operators. The large-n expansions for the sums over the He oscillator strength divided by the corresponding transition energy are presented for these series. Using the expansions, the C6 coefficients for the systems involving He(131,3S) and He(131,3P) are calculated and found to be in good agreement with directly calculated values.
Long-range heteronuclear spin locking (HSL) and its application to peptide sequencing
Tokles, Maritherese; Hatvany, Gerard S.; Rinaldi, Peter L.
In this paper, the utility of heteronuclear-spin-locking 2D NMR experiments for structure elucidation from long-range interactions is demonstrated. Long-range { 1H} 13C heteronuclear-shift-correlation spectra via spin locking provides peptide-sequencing information for gramicidin-S with considerably better sensitivity than was previously obtained with other long-range shift-correlation methods such as HOESY and COLOC.
Processor for Real-Time Atmospheric Compensation in Long-Range Imaging Project
National Aeronautics and Space Administration — Long-range imaging is a critical component to many NASA applications including range surveillance, launch tracking, and astronomical observation. However,...
Barttfeld, Pablo; Amoruso, Lucía; Ais, Joaquín; Cukier, Sebastián; Bavassi, Luz; Tomio, Ailin; Manes, Facundo; Ibanez, Agustín; Sigman, Mariano
2013-01-01
Background: The dimensional approach to Autism Spectrum Disorder (ASD) considers ASD as the extreme of a dimension traversing through the entire population. We use electroencephalography (EEG) functional connectivity to explore its potential utility as a biomarker. We hypothesized that individual differences in autistic traits of typical subjects would involve a long-range connectivity diminution within the delta band. Methods: Resting state EEG functional connectivity was measured for 74 ne...
Li, Lin; Alper, Joshua; Alexov, Emil
2016-08-17
Dyneins are important molecular motors involved in many essential biological processes, including cargo transport along microtubules, mitosis, and in cilia. Dynein motility involves the coupling of microtubule binding and unbinding to a change in the configuration of the linker domain induced by ATP hydrolysis, which occur some 25 nm apart. This leaves the accuracy of dynein stepping relatively inaccurate and susceptible to thermal noise. Using multi-scale modeling with a computational focusing technique, we demonstrate that the microtubule forms an electrostatic funnel that guides the dynein's microtubule binding domain (MTBD) as it finally docks to the precise, keyed binding location on the microtubule. Furthermore, we demonstrate that electrostatic component of the MTBD's binding free energy is linearly correlated with the velocity and run length of dynein, and we use this linearity to predict the effect of mutating each glutamic and aspartic acid located in MTBD domain to alanine. Lastly, we show that the binding of dynein to the microtubule is associated with conformational changes involving several helices, and we localize flexible hinge points within the stalk helices. Taken all together, we demonstrate that long range electrostatic interactions bring a level of precision to an otherwise noisy dynein stepping process.
48 CFR 1405.404 - Release of long-range acquisition estimates.
2010-10-01
... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Release of long-range acquisition estimates. 1405.404 Section 1405.404 Federal Acquisition Regulations System DEPARTMENT OF THE... Release of long-range acquisition estimates....
48 CFR 1305.404 - Release of long-range acquisition estimates.
2010-10-01
... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Release of long-range acquisition estimates. 1305.404 Section 1305.404 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE... long-range acquisition estimates....
Results of long range beam-beam studies and observations during operation in the LHC
Alemany, R; Buffat, X; Calaga, R; Fitterer, M; Giachino, R; Hemelsoet, GH; Herr, W; Papotti, G; Pieloni, T; Poyer, M; Schaumann, M; Trad, G; Wollmann, D
2011-01-01
We studied possible limitations due to the long range beam-beam effects in the LHC. With a larger number of bunches and collisions in all interaction points, we have reduced the crossing angles to enhance long range beam-beam effects to evaluate their influence on dynamic aperture and losses. Experience from operation with reduced separation was analysed and provides additional evidence.
7 CFR 1717.604 - Long-range engineering plans and construction work plans.
2010-01-01
... construction work plans. (a) All borrowers are required to maintain up-to-date long-range engineering plans and construction work plans (CWPs) in form and substance as set forth in 7 CFR part 1710, subpart F. (b... 7 Agriculture 11 2010-01-01 2010-01-01 false Long-range engineering plans and construction...
Solitons in anharmonic chains with ultra-long-range interatomic interactions
Mingaleev, S F; Mertens, F G; Mingaleev, Serge F.; Gaididei, Yuri B.; Mertens, Franz G.
2000-01-01
We study the influence of long-range interatomic interactions on the properties of supersonic pulse solitons in anharmonic chains. We show that in the case of ultra-long-range (e.g., screened Coulomb) interactions three different types of pulse solitons coexist in a certain velocity interval: one type is unstable but the two others are stable. The high-energy stable soliton is broad and can be described in the quasicontinuum approximation. But the low-energy stable soliton consists of two components, short-range and long-range ones, and can be considered as a bound state of these components.
Bis-Fe(IV): nature's sniper for long-range oxidation.
Geng, Jiafeng; Davis, Ian; Liu, Fange; Liu, Aimin
2014-10-01
Iron-dependent enzymes are prevalent in nature and participate in a wide range of biological redox activities. Frequently, high-valence iron intermediates are involved in the catalytic events of iron-dependent enzymes, especially when the activation of peroxide or molecular oxygen is involved. Building on the fundamental framework of iron-oxygen chemistry, these reactive intermediates constantly attract significant attention from the enzymology community. During the past few decades, tremendous efforts from a number of laboratories have been dedicated to the capture and characterization of these intermediates to improve mechanistic understandings. In 2008, an unprecedented bis-Fe(IV) intermediate was reported in a c-type diheme enzyme, MauG, which is involved in the maturation of a tryptophan tryptophylquinone cofactor of methylamine dehydrogenase. This intermediate, although chemically equivalent to well-characterized high-valence iron intermediates, such as compound I, compound ES, and intermediate Q in methane monooxygenase, as well as the hypothetical Fe(V) species in Rieske non-heme oxygenases, is orders of magnitude more stable than these other high-valence species in the absence of its primary substrate. It has recently been discovered that the bis-Fe(IV) intermediate exhibits a unique near-IR absorption feature which has been attributed to a novel charge-resonance phenomenon. This review compares the properties of MauG with structurally related enzymes, summarizes the current knowledge of this new high-valence iron intermediate, including its chemical origin and structural basis, explores the formation and consequences of charge resonance, and recounts the long-range catalytic mechanism in which bis-Fe(IV) participates. Biological strategies for storing oxidizing equivalents with iron ions are also discussed.
Vexiau, R; Aymar, M; Bouloufa-Maafa, N; Dulieu, O
2015-01-01
We have calculated the isotropic $C\\_6$ coefficients characterizing the long-range van der Waals interaction between two identical heteronuclear alkali-metal diatomic molecules in the same arbitrary vibrational level of their ground electronic state $X^1\\Sigma^+$. We consider the ten species made up of $^7$Li, $^{23}$Na, $^{39}$K, $^{87}$Rb and $^{133}$Cs. Following our previous work [M.~Lepers \\textit{et.~al.}, Phys.~Rev.~A \\textbf{88}, 032709 (2013)] we use the sum-over-state formula inherent to the second-order perturbation theory, composed of the contributions from the transitions within the ground state levels, from the transition between ground-state and excited state levels, and from a crossed term. These calculations involve a combination of experimental and quantum-chemical data for potential energy curves and transition dipole moments. We also investigate the case where the two molecules are in different vibrational levels and we show that the Moelwyn-Hughes approximation is valid provided that it i...
Strategies for leukemic biomarker detection using long-range surface plasmon-polaritons
Krupin, O.; Wang, C.; Berini, P.
2014-09-01
The suitability and use of long-range surface plasmon-polaritons for leukemic biomarker detection is discussed. A novel optical biosensor comprised of gold straight waveguides embedded in CYTOP with an etched microfluidic channel was tested for detecting leukemia in patient serum. Gold surface functionalization involved the interaction of protein G (PG) with antibodies by first adsorbing PG on bare gold and then antibodies (Immunoglobulin G, IgG). Differentiation between healthy and leukemia patients was based on the difference in ratios of Ig kappa (Igκ) and Ig lambda (Igλ) light chains in both serums. The ratio for a normal patient is ~1.4 - 2, whereas for a leukemia patient this ratio is altered. As a receptor (primary antibodies), goat anti-human anti-IgGκ and anti-IgGλ were used to functionalize the surface. Diluted normal and leukemia patient serums were tested over the aforementioned surfaces. The ratios of mass surface densities of IgGκ:IgGλ for normal serum (NS) and patient serum (PS) were found to be 1.55 and 1.92 respectively.
Kuśmierczak, M; Lajeunesse, F; Grand, L; Timofeev, I
2015-01-22
Severe brain injuries can trigger epileptogenesis, a latent period that eventually leads to epilepsy. Previous studies have demonstrated that changes in local connectivity between cortical neurons are a part of the epileptogenic processes. In the present study we aimed to investigate whether changes in long-range connectivity are also involved in epileptogenesis. We performed a large unilateral transection (undercut) of the white matter below the suprasylvian gyrus in cats. After about 2 months, we either injected retrograde tracer (cholera toxin, sub-unit B, CTB) or performed Golgi staining. We analyzed distribution of retrogradely labeled neurons, counted dendritic spines in the neocortex (Golgi staining), and analyzed dendritic orientation in control conditions and after the injury. We found a significant increase in the number of detected cells at the frontal parts of the injured hemisphere, which suggests that the process of axonal sprouting occurs in the deafferented area. The increase in the number of retrogradely stained neurons was accompanied with a significant decrease in neocortical spine density in the undercut area, a reduction in vertical and an increase in horizontal orientation of neuronal processes. The present study shows global morphological changes underlying epileptogenesis. An increased connectivity in the injured cortical regions accompanied with a decrease in spine density suggests that excitatory synapses might be formed on dendritic shafts, which probably contributes to the altered neuronal excitability that was described in previous studies on epileptogenesis.
Chromatin structure, epigenetic mechanisms and long-range interactions in the human insulin locus.
Xu, Z; Lefevre, G M; Felsenfeld, G
2012-10-01
Regulation of gene expression in eukaryotes is largely dependent on variations in chromatin structure. More recently, it has become clear that this may involve not only local chromatin organization but also distant regulatory elements that participate in large-scale chromatin architecture within the nucleus. We describe recent methods that make possible the detection of such structures and apply them to analysis of the human insulin (INS) locus in pancreatic islets. We show that the INS gene is part of an extended 'open' chromatin domain that includes adjacent genes as well. We also find that in islets, the INS promoter is in physical contact with distant sites on the same human chromosome and notably, with the SYT8 gene, located nearly 300 kb away. The strength of the contact between INS and SYT8 is increased by glucose, and this results in stimulation of SYT8 expression. Inhibition of INS transcription decreases SYT8 expression. Furthermore, downregulation of SYT8 results in decreased secretion of insulin. Our results thus establish the existence of a regulatory network between the INS gene and other distant genes through long-range physical interactions, and suggest that such networks may have general importance for insulin biology and diabetes.
Eulerian Simulation of Acoustic Waves Over Long Range in Realistic Environments
Chitta, Subhashini; Steinhoff, John
2015-11-01
In this paper, we describe a new method for computation of long-range acoustics. The approach is a hybrid of near and far-field methods, and is unique in its Eulerian treatment of the far-field propagation. The near-field generated by any existing method to project an acoustic solution onto a spherical surface that surrounds a source. The acoustic field on this source surface is then extended to an arbitrarily large distance in an inhomogeneous far-field. This would normally require an Eulerian solution of the wave equation. However, conventional Eulerian methods have prohibitive grid requirements. This problem is overcome by using a new method, ``Wave Confinement'' (WC) that propagates wave-identifying phase fronts as nonlinear solitary waves that live on grid indefinitely. This involves modification of wave equation by the addition of a nonlinear term without changing the basic conservation properties of the equation. These solitary waves can then be used to ``carry'' the essential integrals of the acoustic wave. For example, arrival time, centroid position and other properties that are invariant as the wave passes a grid point. Because of this property the grid can be made as coarse as necessary, consistent with overall accuracy to resolve atmospheric/ground variations. This work is being funded by the U.S. Army under a Small Business Innovation Research (SBIR) program (contract number: # W911W6-12-C-0036). The authors would like to thank Dr. Frank Caradonna and Dr. Ben W. Sim for this support.
Long-range effect of ion implantation of Raex and Hardox steels
Budzyński, P.; Kamiński, M.; Droździel, A.; Wiertel, M.
2016-09-01
Ion implantation involves introduction of ionized atoms of any element (nitrogen) to metals thanks to the high kinetic energy that they acquired in the electric field. The distribution of nitrogen ions implanted at E = 65 keV energy and D = 1.1017 N+ /cm2 fluence in the steel sample and vacancies produced by them was calculated using the SRIM program. This result was confirmed by RBS measurements. The initial maximum range of the implanted nitrogen ions is ∼⃒0.17 μm. This value is relatively small compared to the influence of nitriding on the thickness surface layer of modified steel piston rings. Measurements of the friction coefficient during the pin-on-disc tribological test were performed under dry friction conditions. The friction coefficient of the implanted sample increased to values characteristic of an unimplanted sample after ca. 1500 measurement cycles. The depth of wear trace is ca. 2.4 μm. This implies that the thickness of the layer modified by the implantation process is ∼⃒2.4 μm and exceeds the initial range of the implanted ions by an order of magnitude. This effect, referred to as a long-range implantation effect, is caused by migration of vacancies and nitrogen atoms into the sample. This phenomenon makes ion implantation a legitimate process of modification of the surface layer in order to enhance the tribological properties of critical components of internal combustion engines such as steel piston rings.
Long-range excitation energy transfer in Langmuir-Blodgett multilayer systems
Draxler, Sonja; Lippitsch, Max E.; Aussenegg, Franz R.
1989-07-01
In Langmuir-Blodgett films containing organic dyes, efficient energy transfer over distances exceeding 100 nm is observed. This exceptionally long-range transfer is interpreted as due to special mutual orientation of the dye molecules.
Long range correction for multi-site Lennard-Jones models and planar interfaces
Werth, Stephan; Horsch, Martin; Vrabec, Jadran; Hasse, Hans
2015-01-01
A slab based long range correction approach for multi-site Lennard-Jones models is presented for systems with a planar film geometry that is based on the work by Janecek, J. Phys. Chem. B 110: 6264 (2006). It is efficient because it relies on a center-of-mass cutoff scheme and scales in terms of numerics almost perfectly with the molecule number. For validation, a series of simulations with the two-center Lennard-Jones model fluid, carbon dioxide and cyclohexane is carried out. The results of the present approach, a site-based long range correction and simulations without any long range correction are compared with respect to the saturated liquid density and the surface tension. The present simulation results exhibit only a weak dependence on the cutoff radius, indicating a high accuracy of the implemented long range correction.
US Fish and Wildlife Service, Department of the Interior — The Cape Romanzof Long Range Radar Site (Cape Romanzof) contains many petroleum-related spills and hazardous substances. Therefore, in 1987 and 1988 a field study...
Long-range coherence of interacting Bose gas of dipolar excitons
Energy Technology Data Exchange (ETDEWEB)
Timofeev, V B; Gorbunov, A V; Larionov, A V [Institute of Solid State Physics, Russian Academy of Sciences, 142432 Chernogolovka (Russian Federation)
2007-07-25
Experiments connected with dipolar exciton Bose condensation in lateral traps are reviewed. Observations of long-range coherence of condensate in ring electrostatic traps in Schottky-diode heterostructures with double and single quantum wells are presented and discussed.
High-Counting Rate Photon Detectors for Long-Range Space Optical Communications Project
National Aeronautics and Space Administration — Long range, RF space communications do not meet anymore the bandwidth requirements or power constraints of future NASA missions. Optical communications offer the...
Performance Study on Priority Strategies for WDM Packet Switches under Long-Range Dependent Traffic
Institute of Scientific and Technical Information of China (English)
Chia-Wei; Yu; Chao-Chih; Chang; Shou-Kuo; Shao; Jingshown; Wu
2003-01-01
The impact of long-range dependent (LRD) traffic on the buffer management schemes for WDM packet switches is studied by simulation. The different priority strategies are compared. The principles of efficient strategy design are also presented.
The Origin of Long-Range Attraction between Hydrophobes in Water
Despa, Florin; Berry, R. Stephen
2006-01-01
When water-coated hydrophobic surfaces meet, direct contacts form between the surfaces, driving water out. However, long-range attractive forces first bring those surfaces close. This analysis reveals the source and strength of the long-range attraction between water-coated hydrophobic surfaces. The origin is in the polarization field produced by the strong correlation and coupling of the dipoles of the water molecules at the surfaces. We show that this polarization field gives rise to dipole...
Entanglement in One-Dimensional Anderson Model with Long-Range Correlated Disorder
Institute of Scientific and Technical Information of China (English)
GUO Zi-Zheng
2008-01-01
@@ By using the measure of concurrence,the entanglement of the ground state in the one-dimensional Anderson model is studied with consideration of the long-range correlations. Three kinds of correlations are discussed.We compare the effects of the long-rang Gaussian and power-law correlations between the site energies on the concurrence,and demonstrate the existence of the band structure of the concurrence in the power-law case.
FAST TRACK COMMUNICATION: Current fluctuations in stochastic systems with long-range memory
Harris, R. J.; Touchette, H.
2009-08-01
We propose a method to calculate the large deviations of current fluctuations in a class of stochastic particle systems with history-dependent rates. Long-range temporal correlations are seen to alter the speed of the large deviation function in analogy with long-range spatial correlations in equilibrium systems. We give some illuminating examples and discuss the applicability of the Gallavotti-Cohen fluctuation theorem.
Identification of coupling DNA motif pairs on long-range chromatin interactions in human K562 cells
Wong, Ka-Chun
2015-09-27
Motivation: The protein-DNA interactions between transcription factors (TFs) and transcription factor binding sites (TFBSs, also known as DNA motifs) are critical activities in gene transcription. The identification of the DNA motifs is a vital task for downstream analysis. Unfortunately, the long-range coupling information between different DNA motifs is still lacking. To fill the void, as the first-of-its-kind study, we have identified the coupling DNA motif pairs on long-range chromatin interactions in human. Results: The coupling DNA motif pairs exhibit substantially higher DNase accessibility than the background sequences. Half of the DNA motifs involved are matched to the existing motif databases, although nearly all of them are enriched with at least one gene ontology term. Their motif instances are also found statistically enriched on the promoter and enhancer regions. Especially, we introduce a novel measurement called motif pairing multiplicity which is defined as the number of motifs that are paired with a given motif on chromatin interactions. Interestingly, we observe that motif pairing multiplicity is linked to several characteristics such as regulatory region type, motif sequence degeneracy, DNase accessibility and pairing genomic distance. Taken into account together, we believe the coupling DNA motif pairs identified in this study can shed lights on the gene transcription mechanism under long-range chromatin interactions. © The Author 2015. Published by Oxford University Press.
Shielding and localization in the presence of long-range hopping
Celardo, G. L.; Kaiser, R.; Borgonovi, F.
2016-10-01
We investigate a paradigmatic model for quantum transport with both nearest-neighbor and infinite-range hopping coupling (independent of the position). Due to long-range homogeneous hopping, a gap between the ground state and the excited states can be induced, which is mathematically equivalent to the superconducting gap. In the gapped regime, the dynamics within the excited-state subspace is shielded from long-range hopping, namely it occurs as if long-range hopping would be absent. This is a cooperative phenomenon since shielding is effective over a time scale that diverges with the system size. We named this effect cooperative shielding. We also discuss the consequences of our findings on Anderson localization. Long-range hopping is usually thought to destroy localization due to the fact that it induces an infinite number of resonances. Contrary to this common lore we show that the excited states display strong localized features when shielding is effective even in the regime of strong long-range coupling. A brief discussion on the extension of our results to generic power-law decaying long-range hopping is also given. Our preliminary results confirm that the effects found for the infinite-range case are generic.
Long-range correlations in stride intervals may emerge from non-chaotic walking dynamics.
Directory of Open Access Journals (Sweden)
Jooeun Ahn
Full Text Available Stride intervals of normal human walking exhibit long-range temporal correlations. Similar to the fractal-like behaviors observed in brain and heart activity, long-range correlations in walking have commonly been interpreted to result from chaotic dynamics and be a signature of health. Several mathematical models have reproduced this behavior by assuming a dominant role of neural central pattern generators (CPGs and/or nonlinear biomechanics to evoke chaos. In this study, we show that a simple walking model without a CPG or biomechanics capable of chaos can reproduce long-range correlations. Stride intervals of the model revealed long-range correlations observed in human walking when the model had moderate orbital stability, which enabled the current stride to affect a future stride even after many steps. This provides a clear counterexample to the common hypothesis that a CPG and/or chaotic dynamics is required to explain the long-range correlations in healthy human walking. Instead, our results suggest that the long-range correlation may result from a combination of noise that is ubiquitous in biological systems and orbital stability that is essential in general rhythmic movements.
Statistical mechanics in biology: how ubiquitous are long-range correlations?
Stanley, H. E.; Buldyrev, S. V.; Goldberger, A. L.; Goldberger, Z. D.; Havlin, S.; Mantegna, R. N.; Ossadnik, S. M.; Peng, C. K.; Simons, M.
1994-01-01
The purpose of this opening talk is to describe examples of recent progress in applying statistical mechanics to biological systems. We first briefly review several biological systems, and then focus on the fractal features characterized by the long-range correlations found recently in DNA sequences containing non-coding material. We discuss the evidence supporting the finding that for sequences containing only coding regions, there are no long-range correlations. We also discuss the recent finding that the exponent alpha characterizing the long-range correlations increases with evolution, and we discuss two related models, the insertion model and the insertion-deletion model, that may account for the presence of long-range correlations. Finally, we summarize the analysis of long-term data on human heartbeats (up to 10(4) heart beats) that supports the possibility that the successive increments in the cardiac beat-to-beat intervals of healthy subjects display scale-invariant, long-range "anti-correlations" (a tendency to beat faster is balanced by a tendency to beat slower later on). In contrast, for a group of subjects with severe heart disease, long-range correlations vanish. This finding suggests that the classical theory of homeostasis, according to which stable physiological processes seek to maintain "constancy," should be extended to account for this type of dynamical, far from equilibrium, behavior.
Long-range electron transport in Geobacter sulfurreducens biofilms is redox gradient-driven.
Snider, Rachel M; Strycharz-Glaven, Sarah M; Tsoi, Stanislav D; Erickson, Jeffrey S; Tender, Leonard M
2012-09-18
Geobacter spp. can acquire energy by coupling intracellular oxidation of organic matter with extracellular electron transfer to an anode (an electrode poised at a metabolically oxidizing potential), forming a biofilm extending many cell lengths away from the anode surface. It has been proposed that long-range electron transport in such biofilms occurs through a network of bound redox cofactors, thought to involve extracellular matrix c-type cytochromes, as occurs for polymers containing discrete redox moieties. Here, we report measurements of electron transport in actively respiring Geobacter sulfurreducens wild type biofilms using interdigitated microelectrode arrays. Measurements when one electrode is used as an anode and the other electrode is used to monitor redox status of the biofilm 15 μm away indicate the presence of an intrabiofilm redox gradient, in which the concentration of electrons residing within the proposed redox cofactor network is higher farther from the anode surface. The magnitude of the redox gradient seems to correlate with current, which is consistent with electron transport from cells in the biofilm to the anode, where electrons effectively diffuse from areas of high to low concentration, hopping between redox cofactors. Comparison with gate measurements, when one electrode is used as an electron source and the other electrode is used as an electron drain, suggests that there are multiple types of redox cofactors in Geobacter biofilms spanning a range in oxidation potential that can engage in electron transport. The majority of these redox cofactors, however, seem to have oxidation potentials too negative to be involved in electron transport when acetate is the electron source.
A simplified method for identification of the vibrational series of long-range states in Na{sub 2}
Energy Technology Data Exchange (ETDEWEB)
Vivanco, F.J.; Paiva, R.R. de; Pedrozo-Peñafiel, E.; Farias, K.M.; Bagnato, V.S., E-mail: franklinze@gmail.com [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Instituto de Fisica
2015-06-15
We performed two-color photoassociative ionization experiments in cold sodium atoms in a dark MOT. We produce a sample where most of the atoms were in the ground hyperfine state F=1. Applying a laser with variable frequency, in the region of 0 to - 32 GHz, we obtained a photoassociative spectra containing sequences of different long-range potentials. Using the scaling law for intermediate states, we identified the vibrational series of involved states, separating the sequences. In this way, we have identified the vibrational series for the 1{sub g}, 0{sup +}{sub u}, and 0{sup -}{sub g} states contributions. (author)
Mao, Xiao-Yuan; Tokay, Tursonjan; Zhou, Hong-Hao; Jin, Wei-Lin
2016-05-31
Epileptic seizures are frequently caused by brain tumors. Traditional anti-epileptic treatments do not acquire satisfactory responses. Preoperative and postoperative seizures seriously influence the quality of life of patients. Thus, tumor-associated epilepsy (TAE) is an important subject of the current research. The delineation of the etiology of epileptogenesis in patients with primary brain tumor may help to find the novel and effective drug targets for treating this disease. In this review, we describe the current status of treatment of TAE. More importantly, we focus on the factors that are involved in the functional connectivity between tumors and stromal cells. We propose that there exist two modes, namely, long-range and short-range modes, which likely trigger neuronal hyperexcitation and subsequent epileptic seizures. The long-range mode is referred to as factors released by tumors including glutamate and GABA, binding to the corresponding receptor on the cellular membrane and causing neuronal hyperactivity, while the short-range mode is considered to involve direct intracellular communication between tumor cells and stromas. Gap junctions and tunneling nanotube network are involved in cellular interconnections. Future investigations focused on those two modes may find a potential novel therapeutic target for treating TAE.
Long-Range Coulomb Effect in Intense Laser-Driven Photoelectron Dynamics
Quan, Wei; Hao, Xiaolei; Chen, Yongju; Yu, Shaogang; Xu, Songpo; Wang, Yanlan; Sun, Renping; Lai, Xuanyang; Wu, Chengyin; Gong, Qihuang; He, Xiantu; Liu, Xiaojun; Chen, Jing
2016-06-01
In strong field atomic physics community, long-range Coulomb interaction has for a long time been overlooked and its significant role in intense laser-driven photoelectron dynamics eluded experimental observations. Here we report an experimental investigation of the effect of long-range Coulomb potential on the dynamics of near-zero-momentum photoelectrons produced in photo-ionization process of noble gas atoms in intense midinfrared laser pulses. By exploring the dependence of photoelectron distributions near zero momentum on laser intensity and wavelength, we unambiguously demonstrate that the long-range tail of the Coulomb potential (i.e., up to several hundreds atomic units) plays an important role in determining the photoelectron dynamics after the pulse ends.
Luo, Albert C J
2011-01-01
In memory of Dr. George Zaslavsky, "Long-range Interactions, Stochasticity and Fractional Dynamics" covers the recent developments of long-range interaction, fractional dynamics, brain dynamics and stochastic theory of turbulence, each chapter was written by established scientists in the field. The book is dedicated to Dr. George Zaslavsky, who was one of three founders of the theory of Hamiltonian chaos. The book discusses self-similarity and stochasticity and fractionality for discrete and continuous dynamical systems, as well as long-range interactions and diluted networks. A comprehensive theory for brain dynamics is also presented. In addition, the complexity and stochasticity for soliton chains and turbulence are addressed. The book is intended for researchers in the field of nonlinear dynamics in mathematics, physics and engineering. Dr. Albert C.J. Luo is a Professor at Southern Illinois University Edwardsville, USA. Dr. Valentin Afraimovich is a Professor at San Luis Potosi University, Mexico.
Long-Range Effects on the Pyroelectric Coefficient of Ferroelectric Superlattice
Institute of Scientific and Technical Information of China (English)
DONG Wen; YAO Dong-Lai; WU Yin-Zhong; LI Zhen-Ya
2002-01-01
Long-range effects on the pyroelectric coefficient of a ferroelectric superlattice consisting of two differentferroelectric materials are investigated based on the transverse Ising model. The effects of the interfacial coupling andthe thickness of one period on the pyroelectric coefficient of the ferroelectric superlattice are studied by taking intoaccount the long-range interaction. It is found that with the increase of the strength of the long-range interaction, thepyroelectric coefficient decreases when the temperature is lower than the phase transition temperature; the number ofthe pyroelectric peaks decreases gradually and the phase transition temperature increases. It is also found that with thedecrease of the interfacial coupling and the thickness of one period, the phase transition temperature and the number ofthe pyroelectric peaks decrease.
Testing Long-Range Beam-Beam Compensation for the LHC Luminosity Upgrade
Rijoff, T L
2012-01-01
The performance of the Large Hadron Collider (LHC) at CERN and its minimum crossing angle are limited by the effect of long-range beam-beam collisions. A wire compensators can mitigate part of the long-range effects and may allow for smaller crossing angles, or higher beam intensity. A prototype long-range wire compensator could be installed in the LHC by 2014/15. Since the originally reserved position for such a wire compensator is not available for this first step, we explore other possible options. Our investigations consider various longitudinal and transverse locations, different wire shapes, different optics configurations and several crossing angles between the two colliding beams. Simulations are carried out with the weak-strong code BBtrack. New postprocessing tools are introduced to analyse tune footprints and particle stability. In particular, a new method for the Lyapunov coefficient calculation is implemented. Submitted as "Tesi di laurea" at the University of Milano, 2012.
The influence of long-range links on spiral waves and their application for control
Institute of Scientific and Technical Information of China (English)
Qian Yu
2012-01-01
The influence of long-range links on spiral waves in an excitable medium has been investigated.Spatiotemporal dynamics in an excitable small-world network transform remarkably when we increase the long-range connection probability P.Spiral waves with few perturbations,broken spiral waves,pseudo spiral turbulence,synchronous oscillations,and homogeneous rest state are discovered under different network structures.Tip number is selected to detect non-equilibrium phase transition between different spatiotemporal patterns.The Kuramoto order parameter is used to identify these patterns and explain the emergence of the rest state.Finally,we use long-range links to successfully control spiral waves and spiral turbulence.
UTag: Long-range Ultra-wideband Passive Radio Frequency Tags
Energy Technology Data Exchange (ETDEWEB)
Dowla, F
2007-03-14
Long-range, ultra-wideband (UWB), passive radio frequency (RF) tags are key components in Radio Frequency IDentification (RFID) system that will revolutionize inventory control and tracking applications. Unlike conventional, battery-operated (active) RFID tags, LLNL's small UWB tags, called 'UTag', operate at long range (up to 20 meters) in harsh, cluttered environments. Because they are battery-less (that is, passive), they have practically infinite lifetimes without human intervention, and they are lower in cost to manufacture and maintain than active RFID tags. These robust, energy-efficient passive tags are remotely powered by UWB radio signals, which are much more difficult to detect, intercept, and jam than conventional narrowband frequencies. The features of long range, battery-less, and low cost give UTag significant advantage over other existing RFID tags.
Robustness of Estimators of Long-Range Dependence and Self-Similarity under non-Gaussianity
Franzke, Christian L E; Watkins, Nicholas W; Gramacy, Robert B; Hughes, Cecilia
2011-01-01
Long-range dependence and non-Gaussianity are ubiquitous in many natural systems like ecosystems, biological systems and climate. However, it is not always appreciated that both phenomena usually occur together in natural systems and that the superposition of both phenomena constitute the self-similarity of a system. These features, which are common in complex systems, impact the attribution of trends and the occurrence and clustering of extremes. The risk assessment of systems with these properties will lead to different outcomes (e.g. return periods) than the more common assumption of independence of extremes. Two paradigmatic models are discussed which can simultaneously account for long-range dependence and non-Gaussianity: Autoregressive Fractional Integrated Moving Average (ARFIMA) and Linear Fractional Stable Motion (LFSM). Statistical properties of estimators for long-range dependence and self-similarity are critically assessed. It is found that the most popular estimators are not robust. In particula...
Hidden long-range order in a two-dimensional spin-orbit coupled Bose gas
Su, Shih-Wei; Gou, Shih-Chuan; Liao, Renyuan; Fialko, Oleksandr; Brand, Joachim
2016-01-01
A two-dimensional spin-orbit coupled Bose gas is shown to simultaneously possess quasi and true long-range orders in the total and relative phases, respectively. The total phase undergoes a conventional Berenzinskii- Kosterlitz-Thouless transition, where an quasi long-range order is expected. Additionally, the relative phase undergoes an Ising-type transition building up true long-range order, which is induced by the anisotropic spin- orbit coupling. Based on the Bogoliubov approach, expressions for the total- and relative-phase fluctuations are derived analytically for the low temperature regime. Numerical simulations of the stochastic projected Gross- Pitaevskii equation give a good agreement with the analytical predictions.
Self-sustained target waves in excitable media with only a long-range link
Institute of Scientific and Technical Information of China (English)
Qian Yu; Wang Can-Jun; Shi Hu-Shan; Mi Yuan-Yuan; Huang Xiao-Dong
2011-01-01
In this paper we investigate spatiotemporal pattern formation in excitable media with only a long-range link.Besides the trivial solutions of spiral patterns,we find the asymptotic self-sustained target waves in the autonomous tissues.The wave source supporting this kind of new pattern is the oscillatory one-dimensional Winfree-loop self organized under the presence of a long-range link,which is explored by the dominant phase-advanced driving method.Based on this understanding we can effectively regulate the oscillations of excitable media by suitably arranging the long-range link,including construction of self-sustained target waves with controllable period and wave length,or manipulation of system states between different patterns.
Long range electronic transport in microbial nanowires bridging an electrode and scanned probe
Veazey, Joshua; Lampa-Pastirk, Sanela; Walsh, Kathy; Sun, Jiebing; Zhang, Pengpeng; Reguera, Gemma; Tessmer, Stuart
2011-03-01
The filament-like appendages known as pili, expressed by the bacterium Geobacter sulfurreducens, are believed to act as electrically conductive nanowires. Previously, we used scanning tunneling microscopy to study the local density of states at different positions along the wire. However, the long range electron transfer believed to occur in this protein has not been directly observed. Here we discuss a system for verifying long range transport using a scanning probe technique. Transport at distances of more than a few nanometers would require a novel biological electron transfer process. The authors gratefully acknowledge support from the National Science Foundation (MCB-1021948) and the Michigan State University Foundation (Strategic Partnership Grant).
Exploring Flavor-Dependent Long-Range Forces in Long-Baseline Neutrino Oscillation Experiments
Chatterjee, Sabya Sachi; Agarwalla, Sanjib Kumar
2015-01-01
The Standard Model gauge group can be extended with minimal matter content by introducing anomaly free U(1) symmetry, such as $L_e-L_{\\mu}$ or $L_e-L_{\\tau}$. If the neutral gauge boson corresponding to this global symmetry is ultra-light, then it will give rise to flavor-dependent long-range leptonic force, which can have significant impact on neutrino oscillations. For an instance, the electrons inside the Sun can generate a flavor-dependent long-range potential at the Earth surface, which can suppress the $\
High-precision evaluation of the Vibrational spectra of long-range molecules
Tannous, C
2001-01-01
Vibrational spectra of long-range molecules are determined accurately and to arbitrary accuracy with the Canonical Function Method. The energy levels of the $0^-_g$ and $1_u$ electronic states of the $^{23}{\\rm Na}_2$ molecule are determined from the Ground state up to the continuum limit. The method is validated by comparison with previous results obtained by Stwalley et al. using the same potential and Trost et al. whose work is based on the Lennard-Jones potential adapted to long-range molecules.
Long-range correlations in PbPb collisions at 158 a *GeV
Alt, C; Baatar, B; Barna, D; Bartke, J; Betev, L; Bialkowska, H; Blume, C; Boimska, B; Botje, M; Bracinik, J; Bramm, R; Brun, R; Buncic, P; Cerny, V; Christakoglou, P; Chvala, O; Cramer, J G; Csato, P; Darmenov, N; Dimitrov, A; Dinkelaker, P; Eckardt, V; Farantatos, G; Flierl, D; Fodor, Z; Foka, P; Freund, P; Friese, V; Gal, J; Gazdzicki, M; Georgopoulos, G; Gladysz, E; Grebieszkow, K; Hegyi, S; Hohne, C; Kadija, K; Karev, A; Kliemant, M; Kniege, S; Kolesnikov, V I; Kollegger, T; Kornas, E; Korus, R; Kowalski, M; Kraus, I; Kreps, M; van Leeuwen, M; Levai, P; Litov, L; Lungwitz, B; Makariev, M; Malakhov, A I; Mateev, M; Mayes, B W; Melkumov, G L; Meurer, C; Mischke, A; Mitrovski, M; Molnar, J; Mrowczynski, S; Palla, G; Panagiotou, A D; Panayotov, D; Petridis, A; Pikna, M; Pinsky, L; Puhlhofer, F; Renfordt, R; Richard, A; Roland, C; Roland, G; Rybczynski, M; Rybicki, A; Sandoval, A; Schmitz, N; Seyboth, P; Sikler, F; Sitar, B; Skrzypczak, E; Stefanek, G; Stock, R; Strobele, H; Susa, T; Szentpetery, I; Sziklai, J; Trubnikov, V; Varga, D; Vassiliou, M; Veres, G l; Vesztergombi, G; Vranie, D; Wetzler, A; Wlodarczyk, Z; Yoo, l K; Zaranek, J; Zimanyi, J; Feofilov, G; Kolevatov, R; Kondratiev, V; Naumenko, P; Vechernin, V
2005-01-01
We present the 1st results of the event-by-event study of long-range correlations between event mean Pt and charged particle multiplicity using NA49 experimental data in two separated rapidity intervals in 158 A *Ge V Pb Pb collisions at the CERN SPS. Noticeable long range correlations are found. The most striking feature is the negative Prn correlation observed for the central PbPb collisions. Results are compared to the predictions of the HIJING event generator and of the String Fusion Model favoring a string fusion hypothesis.
Energy funneling in a bent chain of Morse oscillators with long-range coupling
DEFF Research Database (Denmark)
Larsen, Peter Ulrik Vingaard; Christiansen, Peter Leth; Bang, Ole;
2004-01-01
A bent chain of coupled Morse oscillators with long-range dispersive interaction is considered. Moving localized excitations may be trapped in the bending region. Thus chain geometry acts like an impurity. An energy funneling effect is observed in the case of random initial conditions.......A bent chain of coupled Morse oscillators with long-range dispersive interaction is considered. Moving localized excitations may be trapped in the bending region. Thus chain geometry acts like an impurity. An energy funneling effect is observed in the case of random initial conditions....
Dynamic gap generation in graphene under the long-range Coulomb interaction
Energy Technology Data Exchange (ETDEWEB)
Wang Jingrong; Liu Guozhu, E-mail: wangjr@mail.ustc.edu.cn, E-mail: gzliu@ustc.edu.cn [Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui, 230026 (China)
2011-08-31
Dynamic gap generation in graphene under the long-range Coulomb interaction is studied by the Dyson-Schwinger gap equation beyond the instantaneous approximation. Once the dependence of the dynamic gap on the energy has been considered, the critical interaction strength {alpha}{sub c} decreases to 0.542. If the renormalization of the fermion velocity is considered, {alpha}{sub c} will become {alpha}{sub c} = 1.02. This indicates that the dependence on the energy and the renormalization of the fermion velocity are both important for dynamic gap generation in graphene under long-range Coulomb interaction. (paper)
Kinetic theory of spatially homogeneous systems with long-range interactions: II. Basic equations
Chavanis, Pierre-Henri
2013-01-01
We provide a short historic of the early development of kinetic theory in plasma physics and synthesize the basic kinetic equations describing the evolution of systems with long-range interactions derived in Paper I. We describe the evolution of the system as a whole and the relaxation of a test particle in a bath at equilibrium or out-of-equilibrium. We write these equations for an arbitrary long-range potential of interaction in a space of arbitrary dimension d. We discuss the scaling of th...
Non-mean-field effects in systems with long-range forces in competition.
Bachelard, R; Staniscia, F
2012-11-01
We investigate the canonical equilibrium of systems with long-range forces in competition. These forces create a modulation in the interaction potential and modulated phases appear at the system scale. The structure of these phases differentiate this system from monotonic potentials, where only the mean-field and disordered phases exist. With increasing temperature, the system switches from one ordered phase to another through a first-order phase transition. Both mean-field and modulated phases may be stable, even at zero temperature, and the long-range nature of the interaction will lead to metastability characterized by extremely long time scales.
System Estimation of Panel Data Models under Long-Range Dependence
DEFF Research Database (Denmark)
Ergemen, Yunus Emre
A general dynamic panel data model is considered that incorporates individual and interactive fixed effects allowing for contemporaneous correlation in model innovations. The model accommodates general stationary or nonstationary long-range dependence through interactive fixed effects and innovat...... to the long-run relationship between debt and GDP....
75 FR 998 - Terminate Long Range Aids to Navigation (Loran-C) Signal
2010-01-07
... SECURITY Coast Guard Terminate Long Range Aids to Navigation (Loran-C) Signal AGENCY: U.S. Coast Guard, DHS... Homeland Security Appropriations Act. The Act allows for the termination of the Loran-C system subject to the Coast Guard certifying that termination of the Loran-C signal will not adversely impact the...
75 FR 1799 - Terminate Long Range Aids to Navigation (Loran-C) Signal
2010-01-13
... SECURITY Coast Guard Terminate Long Range Aids to Navigation (Loran-C) Signal AGENCY: U.S. Coast Guard, DHS... Navigation (Loran-C) Signal commencing on or about February 8, 2010. The document had an incorrect word in... ``Transmission of the Loran-C signal and phased decommissioning of the Loran-C infrastructure will commence on...
Bloch-like oscillations in a one-dimensional lattice with long-range correlated disorder.
Domínguez-Adame, F; Malyshev, V A; de Moura, F A B F; Lyra, M L
2003-11-01
We study the dynamics of an electron subjected to a uniform electric field within a tight-binding model with long-range-correlated diagonal disorder. The random distribution of site energies is assumed to have a power spectrum S(k) approximately 1/k(alpha) with alpha>0. de Moura and Lyra [Phys. Rev. Lett. 81, 3735 (1998)
Tunable long range forces mediated by self-propelled colloidal hard spheres
Ni, R.; Cohen Stuart, M.A.; Bolhuis, P.G.
2015-01-01
Using Brownian dynamics simulations, we systematically study the effective interaction between two parallel hard walls in a 2D suspension of self-propelled (active) colloidal hard spheres, and we find that the effective force between two hard walls can be tuned from a long range repulsion into a lon
Quantum transport with long-range steps on Watts-Strogatz networks
Wang, Yan; Xu, Xin-Jian
2016-07-01
We study transport dynamics of quantum systems with long-range steps on the Watts-Strogatz network (WSN) which is generated by rewiring links of the regular ring. First, we probe physical systems modeled by the discrete nonlinear schrödinger (DNLS) equation. Using the localized initial condition, we compute the time-averaged occupation probability of the initial site, which is related to the nonlinearity, the long-range steps and rewiring links. Self-trapping transitions occur at large (small) nonlinear parameters for coupling ɛ=-1 (1), as long-range interactions are intensified. The structure disorder induced by random rewiring, however, has dual effects for ɛ=-1 and inhibits the self-trapping behavior for ɛ=1. Second, we investigate continuous-time quantum walks (CTQW) on the regular ring ruled by the discrete linear schrödinger (DLS) equation. It is found that only the presence of the long-range steps does not affect the efficiency of the coherent exciton transport, while only the allowance of random rewiring enhances the partial localization. If both factors are considered simultaneously, localization is greatly strengthened, and the transport becomes worse.
Non-Local Propagation of Correlations in Quantum Systems with Long-Range Interactions
2014-07-10
LETTER doi:10.1038/nature13450 Non-local propagation of correlations in quantum systems with long-range interactions Philip Richerme1, Zhe -Xuan Gong1...2013). 29. James, D. F. V. Quantum dynamics of cold trapped ions with application to quantum computation. Appl. Phys. B 66, 181–190 (1998). 30. Wang
Long-range interacting many-body systems with alkaline-earth-metal atoms.
Olmos, B; Yu, D; Singh, Y; Schreck, F; Bongs, K; Lesanovsky, I
2013-04-01
Alkaline-earth-metal atoms can exhibit long-range dipolar interactions, which are generated via the coherent exchange of photons on the (3)P(0) - (3)D(1) transition of the triplet manifold. In the case of bosonic strontium, which we discuss here, this transition has a wavelength of 2.6 μm and a dipole moment of 4.03 D, and there exists a magic wavelength permitting the creation of optical lattices that are identical for the states (3)P(0) and (3)D(1). This interaction enables the realization and study of mixtures of hard-core lattice bosons featuring long-range hopping, with tunable disorder and anisotropy. We derive the many-body master equation, investigate the dynamics of excitation transport, and analyze spectroscopic signatures stemming from coherent long-range interactions and collective dissipation. Our results show that lattice gases of alkaline-earth-metal atoms permit the creation of long-lived collective atomic states and constitute a simple and versatile platform for the exploration of many-body systems with long-range interactions. As such, they represent an alternative to current related efforts employing Rydberg gases, atoms with large magnetic moment, or polar molecules.
People...Serving People; A 1977 Long-Range User Program for Nebraska Libraries.
Nebraska Library Commission, Lincoln.
In order to design an effective long-range program for human beings, a planner must face the realization that: (1) library users are the only valid sources for evaluating services; (2) empathy for those whom the library intends to serve must be the primary concern; and (3) stated criteria for evaluating library service must be in measurable terms.…
Data transmission in long-range dielectric-loaded surface plasmon polariton waveguides
DEFF Research Database (Denmark)
Kharitonov, S.; Kiselev, R.; Kumar, Ashwani;
2014-01-01
We demonstrate the data transmission of 10 Gbit/s on-off keying modulated 1550 nm signal through a long-range dielectric-loaded surface plasmon polariton waveguide structure with negligible signal degradation. In the experiment the bit error rate penalties do not exceed 0.6 dB over the 15 nm...
South Dakota Arts Council Long Range Plan FY 2006-2008
South Dakota Arts Council, 2006
2006-01-01
This report presents South Dakota Arts Council Long Range Plan for Fiscal Years 2006-2008 in terms of how it intends to achieve six goals. These goals are: (1) Enhance quality of life and economic development through the arts; (2) Promote public awareness and support of the arts; (3) Advance the arts as essential to education and life-long…
Enzymatic cellulose oxidation is linked to lignin by long-range electron transfer
DEFF Research Database (Denmark)
Westereng, Bjorge; Cannella, David; Wittrup Agger, Jane;
2015-01-01
cell walls. Electron transfer was confirmed by electron paramagnetic resonance spectroscopy showing that LPMO activity on cellulose changes the level of unpaired electrons in the lignin. The discovery of a long-range electron transfer mechanism links the biodegradation of cellulose and lignin and sheds...
Nath, Nilamoni; Lokesh; Suryaprakash, Nagarajarao
2012-02-01
The use of long-range heteronuclear couplings, in association with (1)H-(1)H scalar couplings and NOE restraints, has acquired growing importance for the determination of the relative stereochemistry, and structural and conformational information of organic and biological molecules. However, the routine use of such couplings is hindered by the inherent difficulties in their measurement. Prior to the advancement in experimental techniques, both long-range homo- and heteronuclear scalar couplings were not easily accessible, especially for very large molecules. The development of a large number of multidimensional NMR experimental methodologies has alleviated the complications associated with the measurement of couplings of smaller strengths. Subsequent application of these methods and the utilization of determined J-couplings for structure calculations have revolutionized this area of research. Problems in organic, inorganic and biophysical chemistry have also been solved by utilizing the short- and long-range heteronuclear couplings. In this minireview, we discuss the advantages and limitations of a number of experimental techniques reported in recent times for the measurement of long-range heteronuclear couplings and a few selected applications of such couplings. This includes the study of medium- to larger-sized molecules in a variety of applications, especially in the study of hydrogen bonding in biological systems. The utilization of these couplings in conjunction with theoretical calculations to arrive at conclusions on the hyperconjugation, configurational analysis and the effect of the electronegativity of the substituents is also discussed.
Geometrical and Anderson transitions in harmonic chains with constrained long-range couplings.
Morais, P A; Andrade, J S; Nascimento, E M; Lyra, M L
2011-10-01
Low-dimensional systems with long-range couplings usually present phase transitions which are absent in the short-ranged counterpart model. In this work, we show that a harmonic chain with long-range couplings restricted by a cost function proportional to the chain length N exhibits two distinct phase transitions. In the present model, two sites at a distance r>1 are connected by a spring with probability 1/r(α) with the constraint that the total length of the non-nearest-neighbor couplings is limited to λN, where λ is a cost parameter. A geometrical phase transition is found at α=1.5 between a phase with a finite number of long-range couplings and a phase on which the number of long-range couplings is proportional to the system size. Further, the normal vibrational modes of this chain display a phase transition from delocalized to localized modes at a smaller value of α. Maximum effective disorder is reached at α=2 for which the frequency of the lowest vibrational mode exhibits a pronounced peak.
Analysing the origin of long-range interactions in proteins using lattice models
Directory of Open Access Journals (Sweden)
Unger Ron
2009-01-01
Full Text Available Abstract Background Long-range communication is very common in proteins but the physical basis of this phenomenon remains unclear. In order to gain insight into this problem, we decided to explore whether long-range interactions exist in lattice models of proteins. Lattice models of proteins have proven to capture some of the basic properties of real proteins and, thus, can be used for elucidating general principles of protein stability and folding. Results Using a computational version of double-mutant cycle analysis, we show that long-range interactions emerge in lattice models even though they are not an input feature of them. The coupling energy of both short- and long-range pairwise interactions is found to become more positive (destabilizing in a linear fashion with increasing 'contact-frequency', an entropic term that corresponds to the fraction of states in the conformational ensemble of the sequence in which the pair of residues is in contact. A mathematical derivation of the linear dependence of the coupling energy on 'contact-frequency' is provided. Conclusion Our work shows how 'contact-frequency' should be taken into account in attempts to stabilize proteins by introducing (or stabilizing contacts in the native state and/or through 'negative design' of non-native contacts.
Switching between bistable states in a discrete nonlinear model with long-range dispersion
DEFF Research Database (Denmark)
Johansson, Magnus; Gaididei, Yuri B.; Christiansen, Peter Leth
1998-01-01
In the framework of a discrete nonlinear Schrodinger equation with long-range dispersion, we propose a general mechanism for obtaining a controlled switching between bistable localized excitations. We show that the application of a spatially symmetric kick leads to the excitation of an internal...
Addressing Spatial Variability of Surface-Layer Wind with Long-Range WindScanners
DEFF Research Database (Denmark)
Berg, Jacob; Vasiljevic, Nikola; Kelly, Mark C.;
2015-01-01
This paper presents an analysis of mean wind measurements from a coordinated system of long-range WindScanners. From individual scan patterns the mean wind field was reconstructed over a large area, and hence it highlights the spatial variability. From comparison with sonic anemometers, the quality...
Klasmeier, Jörg; Matthies, Michael; Macleod, Matthew; Fenner, Kathrin; Scheringer, Martin; Stroebe, Maximilian; Gall, Anne Christine le; McKone, Thomas; Meent, Dik van de; Wania, Frank
2006-01-01
We propose a multimedia model-based methodology to evaluate whether a chemical substance qualifies as POP-like based on overall persistence (Pov) and potential for long-range transport (LRTP). It relies upon screening chemicals against the Pov and LRTP characteristics of selected reference chemicals
Enzymatic cellulose oxidation is linked to lignin by long-range electron transfer
DEFF Research Database (Denmark)
Westereng, Bjorge; Cannella, David; Wittrup Agger, Jane;
2015-01-01
cell walls. Electron transfer was confirmed by electron paramagnetic resonance spectroscopy showing that LPMO activity on cellulose changes the level of unpaired electrons in the lignin. The discovery of a long-range electron transfer mechanism links the biodegradation of cellulose and lignin and sheds...... new light on how oxidative enzymes present in plant degraders may act in concert....
Free cooling of hard-spheres with short and long range interactions
Gonzalez, S.; Thornton, A.R.; Luding, S.
2015-01-01
We study the stability, the clustering and the phase-diagram of free cooling granular gases. The systems consist of mono-disperse particles with additional non-contact (long-range) interactions, and are simulated here by the event-driven molecular dynamics algorithm with discrete (short-range should
Free cooling phase-diagram of hard-spheres with short- and long-range interactions
Gonzalez Briones, J.S.L.; Thornton, A.R.; Luding, S.
2014-01-01
We study the stability, the clustering and the phase-diagram of free cooling granular gases. The systems consist of mono-disperse particles with additional non-contact (long-range) interactions, and are simulated here by the event-driven molecular dynamics algorithm with discrete (short-range should
Robustness of Estimators of Long-Range Dependence and Self-Similarity under non-Gaussianity
Franzke, C.; Watkins, N. W.; Graves, T.; Gramacy, R.; Hughes, C.
2011-12-01
Long-range dependence and non-Gaussianity are ubiquitous in many natural systems like ecosystems, biological systems and climate. However, it is not always appreciated that both phenomena may occur together in natural systems and that self-similarity in a system can be a superposition of both phenomena. These features, which are common in complex systems, impact the attribution of trends and the occurrence and clustering of extremes. The risk assessment of systems with these properties will lead to different outcomes (e.g. return periods) than the more common assumption of independence of extremes. Two paradigmatic models are discussed which can simultaneously account for long-range dependence and non-Gaussianity: Autoregressive Fractional Integrated Moving Average (ARFIMA) and Linear Fractional Stable Motion (LFSM). Statistical properties of estimators for long-range dependence and self-similarity are critically assessed. It is found that the most popular estimators can be biased in the presence of important features of many natural systems like trends and multiplicative noise. Also the long-range dependence and non-Gaussianity of two typical natural time series are discussed.
Long-range enhancers modulate Foxf1 transcription in blood vessels of pulmonary vascular network.
Seo, Hyejin; Kim, Jinsun; Park, Gi-Hee; Kim, Yuri; Cho, Sung-Won
2016-09-01
Intimate crosstalk occurs between the pulmonary epithelium and the vascular network during lung development. The transcription factor forkhead box f1 (Foxf1) is expressed in the lung mesenchyme and plays an indispensable role in pulmonary angiogenesis. Sonic hedgehog (Shh), a signalling molecule, is expressed in lung epithelium and is required to establish proper angiogenesis. It has been suggested that Foxf1, a downstream target of the Shh signalling pathway, mediates interaction between angiogenesis and the epithelium in lung. However, there has been no clear evidence showing the mechanism how Foxf1 is regulated by Shh signalling pathway during lung development. In this study, we investigated the lung-specific enhancers of Foxf1 and the Gli binding on the enhancers. At first, we found three evolutionarily conserved Foxf1 enhancers, two of which were long-range enhancers. Of the long-range enhancers, one demonstrated tissue-specific activity in the proximal and distal pulmonary blood vessels, while the other one demonstrated activity only in distal blood vessels. At analogous positions in human, these long-range enhancers were included in a regulatory region that was reportedly repeatedly deleted in alveolar capillary dysplasia with misalignment of pulmonary vein patients, which indicates the importance of these enhancers in pulmonary blood vessel formation. We also determined that Gli increased the activity of one of these long-range enhancers, which was specific to distal blood vessel, suggesting that Shh regulates Foxf1 transcription in pulmonary distal blood vessel formation.
Long-range protein electron transfer observed at the single-molecule level
DEFF Research Database (Denmark)
Chi, Qijin; Farver, Ole; Ulstrup, Jens
2005-01-01
A biomimetic long-range electron transfer (ET) system consisting of the blue copper protein azurin, a tunneling barrier bridge, and a gold single-crystal electrode was designed on the basis of molecular wiring self-assembly principles. This system is sufficiently stable and sensitive in a quasi...
Evaluation of the long-rang dispersion of radionuclides from the Chernobyl accident
Energy Technology Data Exchange (ETDEWEB)
Suh, K.S.; Jeong, H.J.; Kim, E.H.; Hwang, W.T.; Han, M.H. [Korea Atomic Energy Research Institute (KAERI), Nuclear Environmental Research Div., Daejeon (Korea, Republic of)
2006-07-01
The atmospheric dispersion models have been developed to predict and minimize the radiological damage for the surrounding environment since the Chernobyl accident. There are many nuclear power plants in the region of Northeast Asia. It is necessary to develop a long-range atmospheric dispersion model for the radiological emergency preparedness against a nuclear accident. From this viewpoint, a Lagrangian particle model named L.A.D.A.S.(Long-range Accident Dose Assessment System) was initially developed for the evaluation the long-range dispersion in Korea since 2001. The model designed to estimate air concentrations and dry deposition as well as wet deposition at distances up to some thousands of kilometers from the source point in a horizontal direction. The validation study of the model was firstly performed by comparing the measured values of E.T.E.X. exercise. The developed model was also applied to simulate the movements of the radioactive materials at the Chernobyl accident. An intercomparison and validation study among the long-range models was performed through the A.T.M.E.S.(Atmospheric Transport Model Evaluation Study) project under auspices of the IAEA/W.M.O. (world meteorological organization) in 1992. As a consequence of A.T.M.E.S., it was observed that in a real emergency case, under conditions of urgency and stress, many of the models would have had different results. So, one of the main recommendations was the launch of a long-range atmospheric tracer experiment in conditions as close as possible to those which could be found in a real emergency case, with the advantage of a complete knowledge of the source term. In this study, numerical simulations were carried out to estimate the concentration distributions of {sup 137}Cs. The calculated results agreed well with them by Chernobyl accident. In conclusion, a three dimensional Lagrangian particle model named L.A.D.A.S. was developed to evaluate the characteristics of a long-range atmospheric
The Characteristics of Long-range Transboundary Inorganic Secondary Aerosols in Northeast Asia
Kim, Y. J.; Carmichael, G. R.; Woo, J. H.; Qiang, Z.
2014-12-01
Recurrent particle matter episodes greatly influence air quality in Northeast Asia. According to many studies, a major reason is long-range transport of air pollutant. Large amount of emission of chemical compounds aggravate air pollution in the region. Emitted air pollutants mainly come from industrialized regions along the East China coast. It can be transported over downwind region by the prevailing westerlies. The long-rang transported fine particle certainly attributes to air quality in downwind region, but there are many unknowns on the quantity, transport pattern, and secondary aerosol production mechanism despite the fact with many studies have been performed. Major contributors of PM2.5 are inorganic secondary aerosols, sulfate, nitrate and ammonium, in Korea. Especially high relative contributions of inorganic secondary aerosols appear for westerly wind cases. The main pathway of production of inorganic secondary aerosols is produced by converting from SO2 and NOx during the long-range transport but the contribution varies dramatically depending on season and wind pattern. Sulfate is consistently the primary contributor of PM2.5 still now but we should more concern nitrate because that NOx emissions of China is increasing steeply since 2000 by leading powerplant, industry, and transport, despite downward trend of SO2. In order to better understand regional air quality modeling of the long-range transport, international study, MICS-Asia phase III, has been initiated with many researchers. We will present chemical characteristics of PM2.5 long-range transport during westerly wind cases focused on secondary aerosol, tracking their transport pattern, and production pathway. Results using CMAQ with the modeling domain covering Northeast and Southeast China, Korea, and Japan with 15km resolution will be discussed.
Unitary S matrices with long-range correlations and the quantum black hole
Akhoury, Ratindranath
2014-08-01
applicable generally to all theories with long range correlations including the final state projection models. As a nontrivial check, we use it in the perturbative context to analyze infrared divergences in QED and thereby reproduce the Faddeev-Kulish theory of asymptotic dynamics.
Energy Technology Data Exchange (ETDEWEB)
Teller, E; Leith, C; Canavan, G; Wood, L
2001-11-13
impacts of weather involve continuing costs of the order of 1% of GDP, a large fraction of which could be retrieved if high-fidelity predictions of two weeks forward applicability were available. These {approx}$10{sup 2} B annual savings dwarf the <$1 B costs of operating a rational, long-range weather prediction system of the type proposed.
Chen, L; Sumbilla, C; Lewis, D; Zhong, L; Strock, C; Kirtley, M E; Inesi, G
1996-05-01
Mutational analysis of several amino acids in the transmembrane region of the sarcoplasmic reticulum ATPase was performed by expressing wild type ATPase and 32 site-directed mutants in COS-1 cells followed by functional characterization of the microsomal fraction. Four different phenotype characteristics were observed in the mutants: (a) functions similar to those sustained by the wild type ATPase; (b) Ca2+ transport inhibited to a greater extent than ATPase hydrolytic activity; (c) inhibition of transport and hydrolytic activity in the presence of high levels of phosphorylated enzyme intermediate; and (d) total inhibition of ATP utilization by the enzyme while retaining the ability to form phosphoenzyme by utilization of P(i). Analysis of experimental observations and molecular models revealed short and long range functions of several amino acids within the transmembrane region. Short range functions include: (a) direct involvement of five amino acids in Ca2+ binding within a channel formed by clustered transmembrane helices M4, M5, M6, and M8; (b) roles of several amino acids in structural stabilization of the helical cluster for optimal channel function; and (c) a specific role of Lys297 in sealing the distal end of the channel, suggesting that the M4 helix rotates to allow vectorial flux of Ca2+ upon enzyme phosphorylation. Long range functions are related to the influence of several transmembrane amino acids on phosphorylation reactions with ATP or P(i), transmitted to the extramembranous region of the ATPase in the presence or in the absence of Ca2+.
Energy Technology Data Exchange (ETDEWEB)
Meng, Hao, E-mail: menghao1982@shu.edu.cn [School of Physics and Telecommunication Engineering, Shaanxi University of Technology, Hanzhong 723001 (China); National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Wu, Xiuqiang [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Ren, Yajie [School of Physics and Telecommunication Engineering, Shaanxi University of Technology, Hanzhong 723001 (China)
2015-01-14
We study the supercurrent in clean superconductor-ferromagnet-superconductor heterostructure containing a noncollinear magnetic domain in the ferromagnetic region. It is demonstrated that the magnetic domain can lead to a spin-flip scattering process, which reverses the spin orientations of the singlet Cooper pair and simultaneously changes the sign of the corresponding electronic momentum. If the ferromagnetic layers on both sides of magnetic domain have the same features, the long-range proximity effect will take place. That is because the singlet Cooper pair will create an exact phase-cancellation effect and gets an additional π phase shift as it passes through the entire ferromagnetic region. Then, the equal spin triplet pair only exists in the magnetic domain region and can not diffuse into the other two ferromagnetic layers. So, the supercurrent mostly arises from the singlet Cooper pairs, and the equal spin triplet pairs are not involved. This result can provide a approach for generating the long-range supercurrent.
Entropy and long-range memory in random symbolic additive Markov chains
Melnik, S. S.; Usatenko, O. V.
2016-06-01
The goal of this paper is to develop an estimate for the entropy of random symbolic sequences with elements belonging to a finite alphabet. As a plausible model, we use the high-order additive stationary ergodic Markov chain with long-range memory. Supposing that the correlations between random elements of the chain are weak, we express the conditional entropy of the sequence by means of the symbolic pair correlation function. We also examine an algorithm for estimating the conditional entropy of finite symbolic sequences. We show that the entropy contains two contributions, i.e., the correlation and the fluctuation. The obtained analytical results are used for numerical evaluation of the entropy of written English texts and DNA nucleotide sequences. The developed theory opens the way for constructing a more consistent and sophisticated approach to describe the systems with strong short-range and weak long-range memory.
Long-range interactions and phase defects in chains of fluid-coupled oscillators
Brumley, Douglas R; Kotar, Jurij; Goldstein, Raymond E; Cicuta, Pietro; Polin, Marco
2016-01-01
Eukaryotic cilia and flagella are chemo-mechanical oscillators capable of generating long-range coordinated motions known as metachronal waves. Pair synchronization is a fundamental requirement for these collective dynamics, but it is generally not sufficient for collective phase-locking, chiefly due to the effect of long-range interactions. Here we explore experimentally and numerically a minimal model for a ciliated surface; hydrodynamically coupled oscillators rotating above a no-slip plane. Increasing their distance from the wall profoundly effects the global dynamics, due to variations in hydrodynamic interaction range. The array undergoes a transition from a traveling wave to either a steady chevron pattern or one punctuated by periodic phase defects. Within the transition between these regimes the system displays behavior reminiscent of chimera states.
Dasbiswas, K.; Alster, E.; Safran, S. A.
2016-06-01
Mechanobiological studies of cell assemblies have generally focused on cells that are, in principle, identical. Here we predict theoretically the effect on cells in culture of locally introduced biochemical signals that diffuse and locally induce cytoskeletal contractility which is initially small. In steady-state, both the concentration profile of the signaling molecule as well as the contractility profile of the cell assembly are inhomogeneous, with a characteristic length that can be of the order of the system size. The long-range nature of this state originates in the elastic interactions of contractile cells (similar to long-range “macroscopic modes” in non-living elastic inclusions) and the non-linear diffusion of the signaling molecules, here termed mechanogens. We suggest model experiments on cell assemblies on substrates that can test the theory as a prelude to its applicability in embryo development where spatial gradients of morphogens initiate cellular development.
Global smooth dynamics of a fully ionized plasma with long-range collisions
Duan, Renjun
2012-01-01
The motion of a fully ionized plasma of electrons and ions is generally governed by the Vlasov-Maxwell-Landau system. We prove the global existence of solutions near Maxwellians to the Cauchy problem of the system for the long-range collision kernel of soft potentials, particularly including the classical Coulomb collision, provided that initial data is smooth enough and decays in velocity variable fast enough. As a byproduct, the convergence rates of solutions are also obtained. The proof is based on the energy method through designing a new temporal energy norm to capture different features of this complex system such as dispersion of the macro component in ${\\mathbb{R}}^3$, singularity of the long-range collisions and regularity-loss of the electromagnetic field.
Vitanov, N K; Vitanov, Nikolay K.; Yankulova, Elka D.
2006-01-01
Time series of heartbeat activity of humans can exhibit long-range correlations. In this paper we show that such kind of correlations can exist for the heartbeat activity of much simpler species like Drosophila melanogaster. By means of the method of multifractal detrended fluctuation analysis (MFDFA) we calculate fractal spectra $f(\\alpha)$ and $h(q)$ and investigate the correlation properties of heartbeat activity of Drosophila with genetic hearth defects for three consequent generations of species. We observe that opposite to the case of humans the time series of the heartbeat activity of healtly Drosophila do not have scaling properties. Time series from flies with genetic defects can be long-range correllated and can have multifractal properties. The fractal heartbeat dynamics of Drosophila is transferred from generation to generation.
Long-range interactions, wobbles, and phase defects in chains of model cilia
Brumley, Douglas R.; Bruot, Nicolas; Kotar, Jurij; Goldstein, Raymond E.; Cicuta, Pietro; Polin, Marco
2016-12-01
Eukaryotic cilia and flagella are chemo-mechanical oscillators capable of generating long-range coordinated motions known as metachronal waves. Pair synchronization is a fundamental requirement for these collective dynamics, but it is generally not sufficient for collective phase-locking, chiefly due to the effect of long-range interactions. Here we explore experimentally and numerically a minimal model for a ciliated surface: hydrodynamically coupled oscillators rotating above a no-slip plane. Increasing their distance from the wall profoundly affects the global dynamics, due to variations in hydrodynamic interaction range. The array undergoes a transition from a traveling wave to either a steady chevron pattern or one punctuated by periodic phase defects. Within the transition between these regimes the system displays behavior reminiscent of chimera states.
Topological massive Dirac edge modes and long-range superconducting Hamiltonians
Viyuela, O.; Vodola, D.; Pupillo, G.; Martin-Delgado, M. A.
2016-09-01
We discover novel topological effects in the one-dimensional Kitaev chain modified by long-range Hamiltonian deformations in the hopping and pairing terms. This class of models display symmetry-protected topological order measured by the Berry/Zak phase of the lower-band eigenvector and the winding number of the Hamiltonians. For exponentially decaying hopping amplitudes, the topological sector can be significantly augmented as the penetration length increases, something experimentally achievable. For power-law decaying superconducting pairings, the massless Majorana modes at the edges get paired together into a massive nonlocal Dirac fermion localized at both edges of the chain: a new topological quasiparticle that we call topological massive Dirac fermion. This topological phase has fractional topological numbers as a consequence of the long-range couplings. Possible applications to current experimental setups and topological quantum computation are also discussed.
Stable distribution and long-range correlation of Brent crude oil market
Yuan, Ying; Zhuang, Xin-tian; Jin, Xiu; Huang, Wei-qiang
2014-11-01
An empirical study of stable distribution and long-range correlation in Brent crude oil market was presented. First, it is found that the empirical distribution of Brent crude oil returns can be fitted well by a stable distribution, which is significantly different from a normal distribution. Second, the detrended fluctuation analysis for the Brent crude oil returns shows that there are long-range correlation in returns. It implies that there are patterns or trends in returns that persist over time. Third, the detrended fluctuation analysis for the Brent crude oil returns shows that after the financial crisis 2008, the Brent crude oil market becomes more persistence. It implies that the financial crisis 2008 could increase the frequency and strength of the interdependence and correlations between the financial time series. All of these findings may be used to improve the current fractal theories.
Characterizing short-range vs. long-range spatial correlations in dislocation distributions
Energy Technology Data Exchange (ETDEWEB)
Chevy, Juliette, E-mail: juliette.chevy@gmail.com [Laboratoire de Glaciologie et Geophysique de l' Environnement-CNRS, 54 rue Moliere, 38402 St. Martin d' Heres (France)] [Laboratoire Science et Ingenierie des Materiaux et Procedes, Grenoble INP-CNRS-UJF, BP 75, 38402 St. Martin d' Heres Cedex (France); Fressengeas, Claude; Lebyodkin, Mikhail; Taupin, Vincent [Laboratoire de Physique et Mecanique des Materiaux, Universite Paul Verlaine-Metz/CNRS, Ile du Saulcy, 57045 Metz Cedex (France); Bastie, Pierre [Laboratoire de Spectrometrie Physique, BP 87, 38402 St. Martin d' Heres Cedex (France)] [Institut Laue Langevin, BP 156, 38042 Grenoble Cedex 9 (France); Duval, Paul [Laboratoire de Glaciologie et Geophysique de l' Environnement-CNRS, 54 rue Moliere, 38402 St. Martin d' Heres (France)
2010-03-15
Hard X-ray diffraction experiments have provided evidence of a strongly heterogeneous distribution of dislocation densities along the axis of cylindrical ice single crystals oriented for basal slip in torsion creep. The dislocation arrangements showed a complex scale-invariant character, which was analyzed by means of statistical and multifractal techniques. A trend to decreasing autocorrelation of the dislocation distribution was observed as deformation proceeds. At low strain levels, long-range spatial correlations control the distribution, but short-range correlations in relation with cross-slip progressively prevail when strain increases. This trend was reproduced by a model based on field dislocation dynamics, a theory accounting for both long-range elastic interactions and short-range interactions through transport of dislocation densities.
Wang, Yang-Yang; Zhang, Tong
2014-01-01
Spontaneous emission noise is an important limit to the performance of active plasmonic devices. Here, we investigate the spontaneous emission noise in the long-range surface plasmon-polariton waveguide based optical gyroscope. A theoretical model of the sensitivity is established to study the incoherent multi-beam interference of spontaneous emission in the gyroscope. Numerical results show that spontaneous emission produces a drift in the transmittance spectra and lowers the signal-to-noise-ratio of the gyroscope. It also strengthens the shot noise to be the main limit to the sensitivity of the gyroscope for high propagation loss. To reduce the negative effects of the spontaneous emission noise on the gyroscope, an external feedback loop is suggested to estimate the drift in the transmittance spectra and therefor enhance the sensitivity. Our work lays a foundation for the improvement of long-range surface plasmon-polariton gyroscope and paves the way to its practical application.
Long Range Force Transmission in Fibrous Matrices Enabled by Tension-Driven Alignment of Fibers
Wang, Hailong; Chen, Christopher S; Wells, Rebecca G; Shenoy, Vivek B
2014-01-01
Cells can sense and respond to mechanical signals over relatively long distances across fibrous extracellular matrices. Here, we explore all of the key factors that influence long range force transmission in cell-populated collagen matrices: alignment of collagen fibers, responses to applied force, strain stiffening properties of the aligned fibers, aspect ratios of the cells, and the polarization of cellular contraction. A constitutive law accounting for mechanically-driven collagen fiber reorientation is proposed. We systematically investigate the range of collagen fiber alignment using both finite element simulations and analytical calculations. Our results show that tension-driven collagen fiber alignment plays a crucial role in force transmission. Small critical stretch for fiber alignment, large fiber stiffness and fiber strain hardening behavior enable long-range interaction. Furthermore, the range of collagen fiber alignment for elliptical cells with polarized contraction is much larger than that for ...
LONG-RANGE CORRELATIONS IN DNA SEQUENCES USING TWO-DIMENSIONAL DNA WALKS
Institute of Scientific and Technical Information of China (English)
Jin Chen; Lin-xi Zhang; De-lu Zhao
2005-01-01
The characterization of long-range correlations and fractal properties of DNA sequences has proved to be a difficult though rewarding task mainly due to the mosaic character of DNA consisting of many patches of various lengths with different nucleotide constitutions. In this paper we investigate statistical correlations among different positions in DNA sequences using the two-dimensional DNA walk. The root-mean-square fluctuation F(l) is described by a power law. The autocorrelation function C(l), which is used to measure the linear dependence and periodicity, exists a power law of C(l) -τμ. We also calculate the mean-square distance ＜R2(l)＞ along the DNA chain, and it may be expressed as ＜R2(l)＞ - l r with 2 ＞γ＞ 1. Our investigations can provide some insights into long-range correlations in DNA sequences.
Anomalous Diffusion and Long-range Correlations in the Score Evolution of the Game of Cricket
Ribeiro, H V; Zeng, Xiao Han T
2012-01-01
We investigate the time evolution of the scores of the second most popular sport in world: the game of cricket. By analyzing the scores event-by-event of more than two thousand matches, we point out that the score dynamics is an anomalous diffusive process. Our analysis reveals that the variance of the process is described by a power-law dependence with a super-diffusive exponent, that the scores are statistically self-similar following a universal Gaussian distribution, and that there are long-range correlations in the score evolution. We employ a generalized Langevin equation with a power-law correlated noise that describe all the empirical findings very well. These observations suggest that competition among agents may be a mechanism leading to anomalous diffusion and long-range correlation.
Anomalous diffusion and long-range correlations in the score evolution of the game of cricket
Ribeiro, Haroldo V.; Mukherjee, Satyam; Zeng, Xiao Han T.
2012-08-01
We investigate the time evolution of the scores of the second most popular sport in the world: the game of cricket. By analyzing, event by event, the scores of more than 2000 matches, we point out that the score dynamics is an anomalous diffusive process. Our analysis reveals that the variance of the process is described by a power-law dependence with a superdiffusive exponent, that the scores are statistically self-similar following a universal Gaussian distribution, and that there are long-range correlations in the score evolution. We employ a generalized Langevin equation with a power-law correlated noise that describes all the empirical findings very well. These observations suggest that competition among agents may be a mechanism leading to anomalous diffusion and long-range correlation.
Entropy and long-range memory in random symbolic additive Markov chains.
Melnik, S S; Usatenko, O V
2016-06-01
The goal of this paper is to develop an estimate for the entropy of random symbolic sequences with elements belonging to a finite alphabet. As a plausible model, we use the high-order additive stationary ergodic Markov chain with long-range memory. Supposing that the correlations between random elements of the chain are weak, we express the conditional entropy of the sequence by means of the symbolic pair correlation function. We also examine an algorithm for estimating the conditional entropy of finite symbolic sequences. We show that the entropy contains two contributions, i.e., the correlation and the fluctuation. The obtained analytical results are used for numerical evaluation of the entropy of written English texts and DNA nucleotide sequences. The developed theory opens the way for constructing a more consistent and sophisticated approach to describe the systems with strong short-range and weak long-range memory.
TIME-FREQUENCY 2-D LMS BASED LONG-RANGE CHANNEL PREDICTION FOR WIRELESS OFDM SYSTEMS
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
Adaptive modulation can optimize the spectrum efficiency and system performance with the channel state information achieved by the long-range channel prediction. To avoid re-estimating channel correlation function as the channel stationarity varies and to track the channel adaptively,LMS (Least-Mean-Square) based long-range channel prediction is discussed in the existing literature,but it needs long observation interval to reach the convergence. Given that all OFDM (Orthogonal Frequency Division Multiplexing) subcarriers have the identical time-domain correlation and stationarity during the same time interval, this paper proposed a 2-D LMS based predictor which updates the filter weights in both time and frequency domain. The proposed scheme can effectively decrease the observation intervals and significantly speed up the convergence than the conventional LMS and Parallel LMS (PLMS). Complexity analysis and simulation results prove that the proposed scheme can improve the BER (Bit Error Rate) performance and spectrum efficiency with negligible complexity increase.
Information resources management long-range plan, FY1994--1998
Energy Technology Data Exchange (ETDEWEB)
1993-04-01
This document describes IRM activities and the information technology resources and capabilities of the Department, the future requirements, and the strategies and plans to satisfy the identified requirements. The long-range planning process provides the systematic means to meet this objective and assists the Department in assuring that information technology (IT) support is provided in an efficient, effective, and timely manner so that its programmatic missions can be accomplished. Another important objective of the Plan is to promote better understanding, both within and external to the Department, of its IT environment, requirements, issues, and recommended solutions. This DOE IRM Plan takes into consideration the IRM requirements of approximately 50 different sites. The annual long-range planning cycle for supporting this Plan was initiated by a Call in August 1991 for site plans to be submitted in February 1992 by those Departmental components and contractors with major IRM requirements.
Long-range visible light communication system based on LED collimating lens
Chen, Yingcong; Wen, Shangsheng; Wu, Yuxiang; Ren, Yuanyuan; Guan, Weipeng; Zhou, Yunlin
2016-10-01
An advanced visible light communication (VLC) system is proposed for long-range VLC, such as marine communication. The design of the system is conducted into two parts. Firstly, we design and optimize a collimating lens for the optical antenna by using Taguchi method. The lighting effects and optical power of the receiving end in different distances are simulated by TracePro software. Then, the long-range VLC channel is reconstructed by integrating the influence of the atmospheric attenuation and frequency response. The performance of the OOK coding VLC system is tested by Matlab software. The results show that: the emitting angle of the optimized collimating lens is 1.7°. By using 1 W LED and collimating lens as an optical antenna, the system can achieve a data rate of 210 Mbit/s at a bit error rate of 10-3 in 90 m.
FY 1991--FY 1995 Information Technology Resources Long-Range Plan
Energy Technology Data Exchange (ETDEWEB)
1989-12-01
The Department of Energy has consolidated its plans for Information Systems, Computing Resources, and Telecommunications into a single document, the Information Technology Resources Long-Range Plan. The consolidation was done as a joint effort by the Office of ADP Management and the Office of Computer Services and Telecommunications Management under the Deputy Assistant Secretary for Administration, Information, and Facilities Management. This Plan is the product of a long-range planning process used to project both future information technology requirements and the resources necessary to meet those requirements. It encompasses the plans of the various organizational components within the Department and its management and operating contractors over the next 5 fiscal years, 1991 through 1995.
Noise-induced dynamical phase transitions in long-range systems.
Chavanis, Pierre-Henri; Baldovin, Fulvio; Orlandini, Enzo
2011-04-01
In the thermodynamic limit, the time evolution of isolated long-range interacting systems is properly described by the Vlasov equation. This equation admits nonequilibrium dynamically stable stationary solutions characterized by a zero order parameter. We show that the presence of external noise sources, such as a heat bath, can reduce their lifetime and induce at a specific time a dynamical phase transition marked by a nonzero order parameter. This transition may be used as a distinctive experimental signature of the temporary existence of nonequilibrium Vlasov-stable states. In particular, we present evidence of a regime characterized by an order parameter pulse. Our analytical results are corroborated by numerical simulations of a paradigmatic long-range model.
Fractional quantum mechanics on networks: Long-range dynamics and quantum transport.
Riascos, A P; Mateos, José L
2015-11-01
In this paper we study the quantum transport on networks with a temporal evolution governed by the fractional Schrödinger equation. We generalize the dynamics based on continuous-time quantum walks, with transitions to nearest neighbors on the network, to the fractional case that allows long-range displacements. By using the fractional Laplacian matrix of a network, we establish a formalism that combines a long-range dynamics with the quantum superposition of states; this general approach applies to any type of connected undirected networks, including regular, random, and complex networks, and can be implemented from the spectral properties of the Laplacian matrix. We study the fractional dynamics and its capacity to explore the network by means of the transition probability, the average probability of return, and global quantities that characterize the efficiency of this quantum process. As a particular case, we explore analytically these quantities for circulant networks such as rings, interacting cycles, and complete graphs.
On the continuum limit for discrete NLS with long-range lattice interactions
Kirkpatrick, Kay; Staffilani, Gigliola
2011-01-01
We consider a general class of discrete nonlinear Schroedinger equations (DNLS) on the lattice $h \\mathbb{Z}$ with mesh size $h>0$. In the continuum limit when $h \\to 0$, we prove that the limiting dynamics are given by a nonlinear Schroedinger equation (NLS) on $\\mathbb{R}$ with the fractional Laplacian $(-\\Delta)^\\alpha$ as dispersive symbol. In particular, we obtain that fractional powers $1/2 < \\alpha < 1$ arise from long-range lattice interactions when passing to the continuum limit, whereas NLS with the non-fractional Laplacian $-\\Delta$ describes the dispersion in the continuum limit for short-range lattice interactions (e.g., nearest-neighbor interactions). Our results rigorously justify certain NLS model equations with fractional Laplacians proposed in the physics literature. Moreover, the arguments given in our paper can be also applied to discuss the continuum limit for other lattice systems with long-range interactions.
Chemical ordering beyond the superstructure in long-range ordered systems
Stana, Markus; Kozubski, Rafal; Leitner, Michael
2016-01-01
To describe chemical ordering in solid solutions systems Warren-Cowley short-range parameters are ordinarily used. However, they are not directly suited for application to long-range ordered systems, as they do not converge to zero for large separations. It is the aim of this paper to generalize the theory to long-range ordered systems and quantitatively discuss chemical short-range order beyond the superstructure arrangements. This is demonstrated on the example of a non-stoichiometric B2-ordered intermetallic alloy. Parameters of interatomic potentials are taken from an embedded atom method (EAM) calculations and the degree of order is simulated by the Monte Carlo method. Both on-lattice and off-lattice methods, where the latter allows individual atoms to deviate from their regular lattice sites, were used, and the resulting effects are discussed.
Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues
2010-10-25
Prompt Global Strike’ Raises Bar for Intel Community.” Inside The Air Force. June 22, 2007. 11 U.S. Department of Defense, Nuclear Posture Review...CRS Report for Congress Prepared for Members and Committees of Congress Conventional Prompt Global Strike and Long-Range Ballistic...DATE 25 OCT 2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Conventional Prompt Global Strike And Long
Agent based reasoning for the non-linear stochastic models of long-range memory
Kononovicius, A.; Gontis, V.
2012-02-01
We extend Kirman's model by introducing variable event time scale. The proposed flexible time scale is equivalent to the variable trading activity observed in financial markets. Stochastic version of the extended Kirman's agent based model is compared to the non-linear stochastic models of long-range memory in financial markets. The agent based model providing matching macroscopic description serves as a microscopic reasoning of the earlier proposed stochastic model exhibiting power law statistics.
[Long-range electron transfer in globular proteins by polaron excitation].
Lakhno, V L; Chuev, G N
1997-01-01
Considering polaron model, we have calculated an electron state localized in the protein heme. Using these calculations: the electron density and electron energy, we estimated the self-exchange rate constant for cyt c (horse heart), its reorganization energy, matrix element, and dependence of this rate on the distance between hemes. The results are compared with the experimental data and other theoretical estimations. We discuss the role of polaron excitations in the long-range electron transfer in globular proteins.
Mobile network architecture of the long-range WindScanner system
Vasiljevic, Nikola; Lea, Guillaume; Hansen, Per; Jensen, Henrik M
2016-01-01
In this report we have presented the network architecture of the long-range WindScanner system that allows utilization of mobile network connections without the use of static public IP addresses. The architecture mitigates the issues of additional fees and contractual obligations that are linked to the acquisition of the mobile network connections with static public IP addresses. The architecture consists of a hardware VPN solution based on the network appliances Z1 and MX60 from Cisco Meraki...
Dynamics of the Random Ising Model with Long-Range Interaction
Institute of Scientific and Technical Information of China (English)
CHEN Yuan; LI Zhi-Bing; FANG Hai; HE Shun-Shan; SITU Shu-Ping
2001-01-01
Critical dynamics of the random Ising model with long-range interaction decaying as r-(d+σ) where d is the dimensionality) is studied by the theoretic renormalization-group approach. The system is released to an evolution within a model A dynamics. Asymptotic scaling laws are studied in a frame of the expansion in = 2σ - d. In dimensions d ＜ 2σ. the dynamic exponent z is calculated to the second order in at the random fixed point.``
Population Dynamics in Cold Gases Resulting from the Long-Range Dipole-Dipole Interaction
Mandilara, A; Pillet, P
2009-01-01
We consider the effect of the long range dipole-dipole interaction on the excitation exchange dynamics of cold two-level atomic gase in the conditions where the size of the atomic cloud is large as compared to the wavelength of the dipole transition. We show that this interaction results in population redistribution across the atomic cloud and in specific spectra of the spontaneous photons emitted at different angles with respect to the direction of atomic polarization.
An Energy-Efficient Link with Adaptive Transmit Power Control for Long Range Networks
DEFF Research Database (Denmark)
Lynggaard, P.; Blaszczyk, Tomasz
2016-01-01
A considerable amount of research is carried out to develop a reliable smart sensor system with high energy efficiency for battery operated wireless IoT devices in the agriculture sector. However, only a limited amount of research has covered automatic transmission power adjustment schemes...... and algorithms which are essential for deployment of wireless IoT nodes. This paper presents an adaptive link algorithm for farm applications with emphasis on power adjustment for long range communication networks....
Absence of Long-Range Coherence in the Parametric Emission from Photonic Wires
Wouters, M.; Carusotto, I.
2005-01-01
We analytically investigate the spatial coherence properties of the signal emission from one-dimensional optical parametric oscillators. Because of the reduced dimensionality, quantum fluctuations are able to destroy the long-range phase coherence even far above threshold. The spatial decay of coherence is exponential and, for realistic parameters of semiconductor photonic wires in the strong exciton-photon coupling regime, it is predicted to occur on an experimentally accessible length scale.
Use of Long-Range Repetitive Element Polymorphism-PCR To Differentiate Bacillus anthracis Strains
Brumlik, Michael J.; Szymajda, Urszula; Zakowska, Dorota; Liang, Xudong; Redkar, Rajendra J.; Patra, Guy; Del Vecchio, Vito G.
2001-01-01
The genome of Bacillus anthracis is extremely monomorphic, and thus individual strains have often proven to be recalcitrant to differentiation at the molecular level. Long-range repetitive element polymorphism-PCR (LR REP-PCR) was used to differentiate various B. anthracis strains. A single PCR primer derived from a repetitive DNA element was able to amplify variable segments of a bacterial genome as large as 10 kb. We were able to characterize five genetically distinct groups by examining 10...
Detecting long-range correlation with detrended fluctuation analysis: Application to BWR stability
Energy Technology Data Exchange (ETDEWEB)
Espinosa-Paredes, Gilberto [Departamento de Ingenieria de Procesos e Hidraulica, Universidad Autonoma Metropolitana-Iztapalapa, Apartado Postal 55-534, Mexico, DF 09340 (Mexico)]. E-mail: gepe@xanum.uam.mx; Alvarez-Ramirez, Jose [Departamento de Ingenieria de Procesos e Hidraulica, Universidad Autonoma Metropolitana-Iztapalapa, Apartado Postal 55-534, Mexico, DF 09340 (Mexico); Vazquez, Alejandro [Departamento de Ingenieria de Procesos e Hidraulica, Universidad Autonoma Metropolitana-Iztapalapa, Apartado Postal 55-534, Mexico, DF 09340 (Mexico)
2006-11-15
The aim of this paper is to explore the application of detrended fluctuation analysis (DFA) to study boiling water reactor stability. DFA is a scaling method commonly used for detecting long-range correlations in non-stationary time series. This method is based on the random walk theory and was applied to neutronic power signal of Forsmark stability benchmark. Our results shows that the scaling properties breakdown during unstable oscillations.
Real-space, mean-field algorithm to numerically calculate long-range interactions
Cadilhe, A.; Costa, B. V.
2016-02-01
Long-range interactions are known to be of difficult treatment in statistical mechanics models. There are some approaches that introduce a cutoff in the interactions or make use of reaction field approaches. However, those treatments suffer the illness of being of limited use, in particular close to phase transitions. The use of open boundary conditions allows the sum of the long-range interactions over the entire system to be done, however, this approach demands a sum over all degrees of freedom in the system, which makes a numerical treatment prohibitive. Techniques like the Ewald summation or fast multipole expansion account for the exact interactions but are still limited to a few thousands of particles. In this paper we introduce a novel mean-field approach to treat long-range interactions. The method is based in the division of the system in cells. In the inner cell, that contains the particle in sight, the 'local' interactions are computed exactly, the 'far' contributions are then computed as the average over the particles inside a given cell with the particle in sight for each of the remaining cells. Using this approach, the large and small cells limits are exact. At a fixed cell size, the method also becomes exact in the limit of large lattices. We have applied the procedure to the two-dimensional anisotropic dipolar Heisenberg model. A detailed comparison between our method, the exact calculation and the cutoff radius approximation were done. Our results show that the cutoff-cell approach outperforms any cutoff radius approach as it maintains the long-range memory present in these interactions, contrary to the cutoff radius approximation. Besides that, we calculated the critical temperature and the critical behavior of the specific heat of the anisotropic Heisenberg model using our method. The results are in excellent agreement with extensive Monte Carlo simulations using Ewald summation.
First-order phase transition in $1d$ Potts model with long-range interactions
Uzelac, K.; Glumac, Z.
1998-01-01
The first-order phase transition in the one-dimensional $q$-state Potts model with long-range interactions decaying with distance as $1/r^{1+\\sigma}$ has been studied by Monte Carlo numerical simulations for $0 2$. On the basis of finite-size scaling analysis of interface free energy $\\Delta F_L$, specific heat and Binder's fourth order cumulant, we obtain the first-order transition which occurs for $\\sigma$ below a threshold value $\\sigma_c(q)$.
Propagation of singularities for Schr\\"odinger equations with modestly long range type potentials
2013-01-01
In a previous paper by the second author, we discussed a characterization of the microlocal singularities for solutions to Schr\\"odinger equations with long range type perturbations, using solutions to a Hamilton-Jacobi equation. In this paper we show that we may use Dollard type approximate solutions to the Hamilton-Jacobi equation if the perturbation satisfies somewhat stronger conditions. As applications, we describe the propagation of microlocal singularities for $e^{itH_0}e^{-itH}$ when ...
Multi-scale variability and long-range memory in indoor Radon concentrations from Coimbra, Portugal
Donner, Reik V.; Potirakis, Stelios; Barbosa, Susana
2014-05-01
The presence or absence of long-range correlations in the variations of indoor Radon concentrations has recently attracted considerable interest. As a radioactive gas naturally emitted from the ground in certain geological settings, understanding environmental factors controlling Radon concentrations and their dynamics is important for estimating its effect on human health and the efficiency of possible measures for reducing the corresponding exposition. In this work, we re-analyze two high-resolution records of indoor Radon concentrations from Coimbra, Portugal, each of which spans several months of continuous measurements. In order to evaluate the presence of long-range correlations and fractal scaling, we utilize a multiplicity of complementary methods, including power spectral analysis, ARFIMA modeling, classical and multi-fractal detrended fluctuation analysis, and two different estimators of the signals' fractal dimensions. Power spectra and fluctuation functions reveal some complex behavior with qualitatively different properties on different time-scales: white noise in the high-frequency part, indications of some long-range correlated process dominating time scales of several hours to days, and pronounced low-frequency variability associated with tidal and/or meteorological forcing. In order to further decompose these different scales of variability, we apply two different approaches. On the one hand, applying multi-resolution analysis based on the discrete wavelet transform allows separately studying contributions on different time scales and characterize their specific correlation and scaling properties. On the other hand, singular system analysis (SSA) provides a reconstruction of the essential modes of variability. Specifically, by considering only the first leading SSA modes, we achieve an efficient de-noising of our environmental signals, highlighting the low-frequency variations together with some distinct scaling on sub-daily time-scales resembling
Longe-Range Order in beta-Brass Studied by Neutron Diffraction
DEFF Research Database (Denmark)
Rathmann, Ole; Als-Nielsen, Jens Aage
1974-01-01
The long-range order, M(T), in β-brass has been measured by neutron diffraction from a small extinction-free crystal. The results agree with those obtained recently by x-ray diffraction. Near Tc our data are in accordance with a power law M(T)=D(1-T/Tc)β with the critical exponent β=0.293 as pred...
An Energy-Efficient Link with Adaptive Transmit Power Control for Long Range Networks
DEFF Research Database (Denmark)
Lynggaard, Per; Blaszczyk, tomasz
2016-01-01
— A considerable amount of research is carried out to develop a reliable smart sensor system with high energy efficiency for battery operated wireless IoT devices in the agriculture sector. However, only a limited amount of research has covered automatic transmission power adjustment schemes...... and algorithms which are essential for deployment of wireless IoT nodes. This paper presents an adaptive link algorithm for farm applications with emphasis on power adjustment for long range communication networks....
Evidence for a role of vertebrate Disp1 in long-range Shh signaling
Etheridge, L. Alton; Crawford, T. Quinn; Zhang, Shile; Roelink, Henk
2010-01-01
Dispatched 1 (Disp1) encodes a twelve transmembrane domain protein that is required for long-range sonic hedgehog (Shh) signaling. Inhibition of Disp1 function, both by RNAi or dominant-negative constructs, prevents secretion and results in the accumulation of Shh in source cells. Measuring the Shh response in neuralized embryoid bodies (EBs) derived from embryonic stem (ES) cells, with or without Disp1 function, demonstrates an additional role for Disp1 in cells transporting Shh. Co-cultures...
Long-range Electron Transport in Geobacter sulfurreducens Biofilms is Redox Gradient-Driven
2012-01-01
anodes of electrochemical reactors , result- ing in electrical current coupled to metabolic organic matter oxidation (18). When grown using an anode as...cells and microbial electrolysis cells. It may also provide valuable insights into the mechanism of long-range biological electron transport in...from industrial and agricultural waste- water . Trends Biotechnol 22:477–485. 55. Rozendal RA, Hamelers HVM, Rabaey K, Keller J, Buisman CJN (2008
Long-ranged contributions to solvation free energies from theory and short-ranged models
Remsing, Richard C.; Liu, Shule; Weeks, John D.
2016-03-01
Long-standing problems associated with long-ranged electrostatic interactions have plagued theory and simulation alike. Traditional lattice sum (Ewald-like) treatments of Coulomb interactions add significant overhead to computer simulations and can produce artifacts from spurious interactions between simulation cell images. These subtle issues become particularly apparent when estimating thermodynamic quantities, such as free energies of solvation in charged and polar systems, to which long-ranged Coulomb interactions typically make a large contribution. In this paper, we develop a framework for determining very accurate solvation free energies of systems with long-ranged interactions from models that interact with purely short-ranged potentials. Our approach is generally applicable and can be combined with existing computational and theoretical techniques for estimating solvation thermodynamics. We demonstrate the utility of our approach by examining the hydration thermodynamics of hydrophobic and ionic solutes and the solvation of a large, highly charged colloid that exhibits overcharging, a complex nonlinear electrostatic phenomenon whereby counterions from the solvent effectively overscreen and locally invert the integrated charge of the solvated object.
Moore, Stan G; Crozier, Paul S
2014-06-21
Several extensions and improvements have been made to the multilevel summation method (MSM) of computing long-range electrostatic interactions. These include pressure calculation, an improved error estimator, faster direct part calculation, extension to non-orthogonal (triclinic) systems, and parallelization using the domain decomposition method. MSM also allows fully non-periodic long-range electrostatics calculations which are not possible using traditional Ewald-based methods. In spite of these significant improvements to the MSM algorithm, the particle-particle particle-mesh (PPPM) method was still found to be faster for the periodic systems we tested on a single processor. However, the fast Fourier transforms (FFTs) that PPPM relies on represent a major scaling bottleneck for the method when running on many cores (because the many-to-many communication pattern of the FFT becomes expensive) and MSM scales better than PPPM when using a large core count for two test problems on Sandia's Redsky machine. This FFT bottleneck can be reduced by running PPPM on only a subset of the total processors. MSM is most competitive for relatively low accuracy calculations. On Sandia's Chama machine, however, PPPM is found to scale better than MSM for all core counts that we tested. These results suggest that PPPM is usually more efficient than MSM for typical problems running on current high performance computers. However, further improvements to MSM algorithm could increase its competitiveness for calculation of long-range electrostatic interactions.
Exchange Mechanisms in Long Range Ordered Thin Film Organic Magnetic Semiconductors
Rawat, N.; Headrick, R.; Furis, M.; McGill, S.; Kilanski, L.; Waterman, R.
2014-03-01
Magnetic exchange mechanisms in crystalline thin films of Metal Phthalocyanines (M-Pc) are explored using Magnetic Circular Dichroism (MCD) and SQUID measurements up to 10 T and 2K. Long range ordered thin films of organo-soluble derivatives of Co-Pc and Mn-Pc were fabricated using solution processing technique. In the case of Mn-Pc, our measurements show enhanced hybridization of ligand π-electronic states with the Mn d-orbitals. MCD active states beyond 1 μm have been observed for the first time, providing crucial information on the orbital arrangements of MPc's that result in competing (co-existing) long-range superexchange and indirect exchange reminiscent of RKKY. The evolution of Zeeman splitting of specific MCD-active states is very well described by enhanced effective π-electrons g-factors as large as 100, analogous to diluted magnetic semiconductors (DMS) systems. In Co-Pc MCD data indicates a weaker exchange interaction between delocalized charge carriers and d-like spin-polarized electrons, however SQUID measurements reveal magnetic ordering up to 180K. A comparison between Mn-Pc and Co-Pc and earlier results from the spin 1/2 Cu-Pc and their non-magnetic Zn-Pc counterpart, offers an interesting view on the role of long range order in magnetic interactions. NSF, MRI and CAREER programs: DMR- 0722451; DMR-0348354; DMR- 0821268; DMR-1056589.
Short- and long-range neural synchrony in grapheme-color synesthesia.
Volberg, Gregor; Karmann, Anna; Birkner, Stefanie; Greenlee, Mark W
2013-07-01
Grapheme-color synesthesia is a perceptual phenomenon where single graphemes (e.g., the letter "E") induce simultaneous sensations of colors (e.g., the color green) that were not objectively shown. Current models disagree as to whether the color sensations arise from increased short-range connectivity between anatomically adjacent grapheme- and color-processing brain structures or from decreased effectiveness of inhibitory long-range connections feeding back into visual cortex. We addressed this issue by examining neural synchrony obtained from EEG activity, in a sample of grapheme-color synesthetes that were presented with color-inducing versus non-color-inducing graphemes. For color-inducing graphemes, the results showed a decrease in the number of long-range couplings in the theta frequency band (4-7 Hz, 280-540 msec) and a concurrent increase of short-range phase-locking within lower beta band (13-20 Hz, 380-420 msec at occipital electrodes). Because the effects were both found in long-range synchrony and later within the visual processing stream, the results support the idea that reduced inhibition is an important factor for the emergence of synesthetic colors.
Singular dynamics and emergence of nonlocality in long-range quantum models
Lepori, L; Vodola, D
2016-01-01
We discuss how nonlocality originates in long-range quantum systems and how it affects their dynamics at and out of the equilibrium. We focus in particular on the Kitaev chains with long-range pairings and on the quantum Ising chain with long-range antiferromagnetic coupling (both having a power-law decay with exponent \\alpha). By studying the dynamic correlation functions, we find that for every finite \\alpha two different behaviours can be identified, one typical of short-range systems and the other connected with locality violation. The latter behaviour is shown related also with the known power-law decay tails previously observed in the static correlation functions, and originated by modes, having in general energies far from the minima of the spectrum, where particular singularities develop as a consequence of the long-rangedness of the system. We refer to these modes as to "singular" modes, and as to "singular dynamics" to their dynamics. For the Kitaev model they are manifest, at finite \\alpha, in deri...
Viability of long range dragonfly migration across the Indian Ocean: An energetics perspective
Saha, Sandeep; Nirwal, Satvik
2016-11-01
Recently Pantala flavescens (dragonflies) have been reported to migrate in millions from India to Eastern Africa on a multigenerational migratory circuit of length 14000-18000 kms. We attempt to understand the ability of dragonflies to perform long range migration by examining the energetics using computer simulations. In absence of a theory for long range insect migrations, we resort to the extensive literature on long range bird migration from the energetics perspective. The flight energetics depends upon instantaneous power and velocity. The mechanical flight power is computed from the power curve which is then converted to mass depletion using Brequet's equation. However, the mechanical flight power itself depends upon the instantaneous velocity which can vary depending upon the current mass. In order to predict the range in our simulations, we assume that the insect progressively tries to achieve the maximum range velocity. The results indicate that the migration range is approximately 1260 kms in 70 hours based on the true airspeed. However, our analysis is restricted by the lack of data and certain caveats in drag prediction and basal metabolism rate.
Song, Sunbin; Garrido, Lúcia; Nagy, Zoltan; Mohammadi, Siawoosh; Steel, Adam; Driver, Jon; Dolan, Ray J; Duchaine, Bradley; Furl, Nicholas
2015-11-01
Individuals with developmental prosopagnosia (DP) experience face recognition impairments despite normal intellect and low-level vision and no history of brain damage. Prior studies using diffusion tensor imaging in small samples of subjects with DP (n=6 or n=8) offer conflicting views on the neurobiological bases for DP, with one suggesting white matter differences in two major long-range tracts running through the temporal cortex, and another suggesting white matter differences confined to fibers local to ventral temporal face-specific functional regions of interest (fROIs) in the fusiform gyrus. Here, we address these inconsistent findings using a comprehensive set of analyzes in a sample of DP subjects larger than both prior studies combined (n=16). While we found no microstructural differences in long-range tracts between DP and age-matched control participants, we found differences local to face-specific fROIs, and relationships between these microstructural measures with face recognition ability. We conclude that subtle differences in local rather than long-range tracts in the ventral temporal lobe are more likely associated with developmental prosopagnosia.
Long-range Rydberg molecules, Rydberg macrodimers and Rydberg aggregates in an ultracold Cs gas
Saßmannshausen, Heiner; Merkt, Frédéric
2016-01-01
We present an overview of our recent investigations of long-range interactions in an ultracold Cs Rydberg gas. These interactions are studied by high-resolution photoassociation spectroscopy, using excitation close to one-photon transitions into $n$p$_{3/2}$ Rydberg states with pulsed and continuous-wave ultraviolet laser radiation, and lead to the formation of long-range Cs$_2$ molecules. We observe two types of molecular resonances. The first type originates from the correlated excitation of two atoms into Rydberg-atom-pair states interacting at long range via multipole-multipole interactions. The second type results from the interaction of one atom excited to a Rydberg state with one atom in the electronic ground state. Which type of resonances is observed in the experiments depends on the laser intensity and frequency and on the pulse sequences used to prepare the Rydberg states. We obtain insights into both types of molecular resonances by modelling the interaction potentials, using a multipole expansion...
Long-range cross-correlation between urban impervious surfaces and land surface temperatures
Nie, Qin; Xu, Jianhua; Man, Wang
2016-03-01
The thermal effect of urban impervious surfaces (UIS) is a complex problem. It is thus necessary to study the relationship between UIS and land surface temperatures (LST) using complexity science theory and methods. This paper investigates the long-range cross-correlation between UIS and LST with detrended cross-correlation analysis and multifractal detrended cross-correlation analysis, utilizing data from downtown Shanghai, China. UIS estimates were obtained from linear spectral mixture analysis, and LST was retrieved through application of the mono-window algorithm, using Landsat Thematic Mapper and Enhanced Thematic Mapper Plus data for 1997-2010. These results highlight a positive long-range cross-correlation between UIS and LST across People's Square in Shanghai. LST has a long memory for a certain spatial range of UIS values, such that a large increment in UIS is likely to be followed by a large increment in LST. While the multifractal long-range cross-correlation between UIS and LST was observed over a longer time period in the W-E direction (2002-2010) than in the N-S (2007-2010), these observed correlations show a weakening during the study period as urbanization increased.
Long-range interacting many-body systems with alkaline-earth-metal atoms
Olmos, B; Singh, Y; Schreck, F; Bongs, K; Lesanovsky, I
2012-01-01
Alkaline-earth-metal atoms exhibit long-range dipolar interactions, which are generated via the coherent exchange of photons on the 3P_0-3D_1-transition of the triplet manifold. In case of bosonic strontium, which we discuss here, this transition has a wavelength of 2.7 \\mu m and a dipole moment of 2.46 Debye, and there exists a magic wavelength permitting the creation of optical lattices that are identical for the states 3P_0 and 3D_1. This interaction enables the realization and study of mixtures of hard-core lattice bosons featuring long-range hopping, with tuneable disorder and anisotropy. We derive the many-body Master equation, investigate the dynamics of excitation transport and analyze spectroscopic signatures stemming from coherent long-range interactions and collective dissipation. Our results show that lattice gases of alkaline-earth-metal atoms permit the creation of long-lived collective atomic states and constitute a simple and versatile platform for the exploration of many-body systems with lon...
Effect of simple solutes on the long range dipolar correlations in liquid water
Baul, Upayan; Kanth, J. Maruthi Pradeep; Anishetty, Ramesh; Vemparala, Satyavani
2016-03-01
Intermolecular correlations in liquid water at ambient conditions have generally been characterized through short range density fluctuations described through the atomic pair distribution functions. Recent numerical and experimental results have suggested that such a description of order or structure in liquid water is incomplete and there exist considerably longer ranged orientational correlations in water that can be studied through dipolar correlations. In this study, using large scale classical, atomistic molecular dynamics simulations using TIP4P-Ew and TIP3P models of water, we show that salts such as sodium chloride (NaCl), potassium chloride (KCl), caesium chloride (CsCl), and magnesium chloride (MgCl2) have a long range effect on the dipolar correlations, which cannot be explained by the notion of structure making and breaking by dissolved ions. Observed effects are explained through orientational stratification of water molecules around ions and their long range coupling to the global hydrogen bond network by virtue of the sum rule for water. The observations for single hydrophilic solutes are contrasted with the same for a single methane (CH4) molecule. We observe that even a single small hydrophobe can result in enhancement of long range orientational correlations in liquid water, contrary to the case of dissolved ions, which have been observed to have a reducing effect. The observations from this study are discussed in the context of hydrophobic effect.
Long-range tactile masking occurs in the postural body schema.
D'Amour, Sarah; Harris, Laurence R
2016-02-01
Long-range tactile masking has been reported between mirror symmetric body locations. This suggests a general principle of contralateral inhibition between corresponding points on each side of the body that may serve to enhance distinguishing touches on the two halves of the body. Do such effects occur before or after posture is added to the body schema? Here, we address this question by exploring the effect of arm position on long-range tactile masking. The influence of arm position was investigated using different positions of both the test and masking arms. Tactile sensitivity was measured on one forearm, while vibrotactile-masking stimulation was applied to the opposite arm or to a control site on the shoulder. No difference was found in sensitivity when test arm position was varied. Physical contact between the arms significantly increased the effectiveness of a masking stimulus applied to the other arm. Long-range masking between the arms was strongest when the arms were held parallel to each other and was abolished if the position of either the test arm or the masking arm was moved from this position. Modulation of the effectiveness of masking by the position of both the test and masking arms suggests that these effects occur after posture information is added to the body's representation in the brain.
Long-range cross-correlation between urban impervious surfaces and land surface temperatures
Institute of Scientific and Technical Information of China (English)
Qin NIE; Jianhua XU; Wang MAN
2016-01-01
The thermal effect of urban impervious surfaces (UIS) is a complex problem.It is thus necessary to study the relationship between UIS and land surface temperatures (LST) using complexity science theory and methods.This paper investigates the long-range cross-correlation between UIS and LST with detrended cross-correlation analysis and multifractal detrended cross-correlation analysis,utilizing data from downtown Shanghai,China.UIS estimates were obtained from linear spectral mixture analysis,and LST was retrieved through application of the mono-window algorithm,using Landsat Thematic Mapper and Enhanced Thematic Mapper Plus data for 1997-2010.These results highlight a positive long-range cross-correlation between UIS and LST across People's Square in Shanghai.LST has a long memory for a certain spatial range of UIS values,such that a large increment in UIS is likely to be followed by a large increment in LST.While the multifractal long-range cross-correlation between UIS and LST was observed over a longer time period in the W-E direction (2002-2010) than in the N-S (2007-2010),these observed correlations show a weakening during the study period as urbanization increased.
Directory of Open Access Journals (Sweden)
Szolgayová Elena
2014-03-01
Full Text Available Short term streamflow forecasting is important for operational control and risk management in hydrology. Despite a wide range of models available, the impact of long range dependence is often neglected when considering short term forecasting. In this paper, the forecasting performance of a new model combining a long range dependent autoregressive fractionally integrated moving average (ARFIMA model with a wavelet transform used as a method of deseasonalization is examined. It is analysed, whether applying wavelets in order to model the seasonal component in a hydrological time series, is an alternative to moving average deseasonalization in combination with an ARFIMA model. The one-to-ten-steps-ahead forecasting performance of this model is compared with two other models, an ARFIMA model with moving average deseasonalization, and a multiresolution wavelet based model. All models are applied to a time series of mean daily discharge exhibiting long range dependence. For one and two day forecasting horizons, the combined wavelet - ARFIMA approach shows a similar performance as the other models tested. However, for longer forecasting horizons, the wavelet deseasonalization - ARFIMA combination outperforms the other two models. The results show that the wavelets provide an attractive alternative to the moving average deseasonalization.
Active and Inactive Enhancers Cooperate to Exert Localized and Long-Range Control of Gene Regulation
Directory of Open Access Journals (Sweden)
Charlotte Proudhon
2016-06-01
Full Text Available V(DJ recombination relies on the presence of proximal enhancers that activate the antigen receptor (AgR loci in a lineage- and stage-specific manner. Unexpectedly, we find that both active and inactive AgR enhancers cooperate to disseminate their effects in a localized and long-range manner. Here, we demonstrate the importance of short-range contacts between active enhancers that constitute an Igk super-enhancer in B cells. Deletion of one element reduces the interaction frequency between other enhancers in the hub, which compromises the transcriptional output of each component. Furthermore, we establish that, in T cells, long-range contact and cooperation between the inactive Igk enhancer MiEκ and the active Tcrb enhancer Eβ alters enrichment of CBFβ binding in a manner that impacts Tcrb recombination. These findings underline the complexities of enhancer regulation and point to a role for localized and long-range enhancer-sharing between active and inactive elements in lineage- and stage-specific control.
Tuneable and robust long range surface plasmon resonance for biosensing applications
Méjard, Régis; Dostálek, Jakub; Huang, Chun-Jen; Griesser, Hans; Thierry, Benjamin
2013-10-01
A multilayered biosensing architecture based on long range surface plasmons (LRSPs) is reported. LRSPs originate from the coupling of surface plasmons on the opposite sides of a thin metal film embedded in a symmetrical refractive index environment. With respect to regular SPs, LRSPs are characterized by extended electromagnetic field profiles and lower losses, making them of high interest in biosensing, especially for large biological entities. LRSPs-supporting layer structures are typically prepared by using fluoropolymers with refractive indices close to that of water. Unfortunately, fluoropolymers have low surface energies which can translate into poor adhesion to substrates and sub-optimal properties of coatings with surface plasmon resonance-active metal layers such as gold. In this work, a multilayered fluoropolymer structure with tuneable average refractive index is described and used to adjust the penetration depth of LRSP from the sensor surface. The proposed methodology also provides a simple solution to increase the adhesion of LRSP-supporting structures to glass substrates. Towards taking full advantage of long range surface plasmon resonance sensors, a novel approach based on the plasma-polymerization of allylamine is also described to improve the quality of gold layers on fluoropolymers such as Teflon AF. Through these advancements, long range surface plasmon resonance sensors were fabricated with figures of merit as high as 466 RIU-1. The remarkable performance of these sensors combined with their high stability is expected to foster applications of LRSPR in biosensing.
Effective theory and breakdown of conformal symmetry in a long-range quantum chain
Lepori, L.; Vodola, D.; Pupillo, G.; Gori, G.; Trombettoni, A.
2016-11-01
We deal with the problem of studying the symmetries and the effective theories of long-range models around their critical points. A prominent issue is to determine whether they possess (or not) conformal symmetry (CS) at criticality and how the presence of CS depends on the range of the interactions. To have a model, both simple to treat and interesting, where to investigate these questions, we focus on the Kitaev chain with long-range pairings decaying with distance as power-law with exponent α. This is a quadratic solvable model, yet displaying non-trivial quantum phase transitions. Two critical lines are found, occurring respectively at a positive and a negative chemical potential. Focusing first on the critical line at positive chemical potential, by means of a renormalization group approach we derive its effective theory close to criticality. Our main result is that the effective action is the sum of two terms: a Dirac action SD, found in the short-range Ising universality class, and an "anomalous" CS breaking term SAN. While SD originates from low-energy excitations in the spectrum, SAN originates from the higher energy modes where singularities develop, due to the long-range nature of the model. At criticality SAN flows to zero for α > 2, while for α effective Lorentz invariance (ELI) for every finite α. As α increases such ELI breakdown becomes less and less pronounced and in the short-range limit α → ∞ the ELI is restored. In order to test the validity of the determined effective theory, we compared the two-fermion static correlation functions and the von Neumann entropy obtained from them with the ones calculated on the lattice, finding agreement. These results explain two observed features characteristic of long-range models, the hybrid decay of static correlation functions within gapped phases and the area-law violation for the von Neumann entropy. The proposed scenario is expected to hold in other long-range models displaying quasiparticle
Long-range correlations in rectal temperature fluctuations of healthy infants during maturation.
Directory of Open Access Journals (Sweden)
Georgette Stern
Full Text Available BACKGROUND: Control of breathing, heart rate, and body temperature are interdependent in infants, where instabilities in thermoregulation can contribute to apneas or even life-threatening events. Identifying abnormalities in thermoregulation is particularly important in the first 6 months of life, where autonomic regulation undergoes critical development. Fluctuations in body temperature have been shown to be sensitive to maturational stage as well as system failure in critically ill patients. We thus aimed to investigate the existence of fractal-like long-range correlations, indicative of temperature control, in night time rectal temperature (T(rec patterns in maturing infants. METHODOLOGY/PRINCIPAL FINDINGS: We measured T(rec fluctuations in infants every 4 weeks from 4 to 20 weeks of age and before and after immunization. Long-range correlations in the temperature series were quantified by the correlation exponent, alpha using detrended fluctuation analysis. The effects of maturation, room temperature, and immunization on the strength of correlation were investigated. We found that T(rec fluctuations exhibit fractal long-range correlations with a mean (SD alpha of 1.51 (0.11, indicating that T(rec is regulated in a highly correlated and hence deterministic manner. A significant increase in alpha with age from 1.42 (0.07 at 4 weeks to 1.58 (0.04 at 20 weeks reflects a change in long-range correlation behavior with maturation towards a smoother and more deterministic temperature regulation, potentially due to the decrease in surface area to body weight ratio in the maturing infant. alpha was not associated with mean room temperature or influenced by immunization CONCLUSIONS: This study shows that the quantification of long-range correlations using alpha derived from detrended fluctuation analysis is an observer-independent tool which can distinguish developmental stages of night time T(rec pattern in young infants, reflective of maturation of
Darré, Leonardo; Machado, Matías Rodrigo; Brandner, Astrid Febe; González, Humberto Carlos; Ferreira, Sebastián; Pantano, Sergio
2015-02-10
Modeling of macromolecular structures and interactions represents an important challenge for computational biology, involving different time and length scales. However, this task can be facilitated through the use of coarse-grained (CG) models, which reduce the number of degrees of freedom and allow efficient exploration of complex conformational spaces. This article presents a new CG protein model named SIRAH, developed to work with explicit solvent and to capture sequence, temperature, and ionic strength effects in a topologically unbiased manner. SIRAH is implemented in GROMACS, and interactions are calculated using a standard pairwise Hamiltonian for classical molecular dynamics simulations. We present a set of simulations that test the capability of SIRAH to produce a qualitatively correct solvation on different amino acids, hydrophilic/hydrophobic interactions, and long-range electrostatic recognition leading to spontaneous association of unstructured peptides and stable structures of single polypeptides and protein-protein complexes.
Pilot system on extreme climate monitoring and early warning for long range forecast in Korea
Cho, K.; Park, B. K.; E-hyung, P.; Gong, Y.; Kim, H. K.; Park, S.; Min, S. K.; Yoo, H. D.
2015-12-01
Recently, extreme weather/climate events such as heat waves, flooding/droughts etc. have been increasing in frequency and intensity under climate change over the world. Also, they can have substantial impacts on ecosystem and human society (agriculture, health, and economy) of the affected regions. According to future projections of climate, extreme weather and climate events in Korea are expected to occure more frequently with stronger intensity over the 21st century. For the better long range forecast, it is also fundamentally ruquired to develop a supporting system in terms of extreme weather and climate events including forequency and trend. In this context, the KMA (Korea Meteorological Administration) has recently initiated a development of the extreme climate monintoring and early warning system for long range forecast, which consists of three sub-system components; (1) Real-time climate monitoring system, (2) Ensemble prediction system, and (3) Mechanism analysis and display system for climate extremes. As a first step, a pilot system has been designed focusing on temperature extremes such heat waves and cold snaps using daily, monthly and seasonal observations and model prediction output on the global, regional and national levels. In parallel, the skills of the KMA long range prediction system are being evaluated comprehensively for weather and climate extremes, for which varous case studies are conducted to better understand the observed variations of extrem climates and responsible mechanisms and also to assess predictability of the ensemble prediction system for extremes. Details in the KMA extreme climate monitoring and early warning system will be intorduced and some preliminary results will be discussed for heat/cold waves in Korea.
The phase transition in the anisotropic Heisenberg model with long range dipolar interactions
Energy Technology Data Exchange (ETDEWEB)
Mól, L.A.S., E-mail: lucasmol@fisica.ufmg.br; Costa, B.V., E-mail: bvc@fisica.ufmg.br
2014-03-15
In this work we have used extensive Monte Carlo calculations to study the planar to paramagnetic phase transition in the two-dimensional anisotropic Heisenberg model with dipolar interactions (AHd) considering the true long-range character of the dipolar interactions by means of the Ewald summation. Our results are consistent with an order–disorder phase transition with unusual critical exponents in agreement with our previous results for the Planar Rotator model with dipolar interactions. Nevertheless, our results disagree with the Renormalization Group results of Maier and Schwabl [Phys. Rev. B, 70, 134430 (2004)] [13] and the results of Rapini et al. [Phys. Rev. B, 75, 014425 (2007)] [12], where the AHd was studied using a cut-off in the evaluation of the dipolar interactions. We argue that besides the long-range character of dipolar interactions their anisotropic character may have a deeper effect in the system than previously believed. Besides, our results show that the use of a cut-off radius in the evaluation of dipolar interactions must be avoided when analyzing the critical behavior of magnetic systems, since it may lead to erroneous results. - Highlights: • The anisotropic Heisenberg model with dipolar interactions is studied. • True long-range interactions were considered by means of Ewald summation. • We found an order–disorder phase transition with unusual critical exponents. • Previous results show a different behavior when a cut-off radius is introduced. • The use of a cut-off radius must be avoided when dealing with dipolar systems.
Impact of Long-Range Dust Transport on Northern California in Spring 2002
Energy Technology Data Exchange (ETDEWEB)
Cameron-Smith, P; Bergmann, D; Chuang, C; Bench, G; Cliff, S; Kelly, P; Perry, K; VanCuren, T
2005-02-10
It has been well documented that spectacular dust storms in Asia (e.g. the events in 1998 and 2001) can affect the USA through long-range transport of dust across the Pacific. However, our observations and modeling show that the majority of dust at sites in Lassen National Park and Trinity Alps (Northern California) in spring 2002 (a year with no spectacular Asian dust events) is still from long-range intercontinental transport across the Pacific. We implemented the interactive dust emission algorithm of Ginoux et al. (2004) into the LLNL 3-D global atmospheric chemistry and aerosol transport model (IMPACT), then ran the model using a separate tracer for each dust emission region, using hi-resolution (1 x 1 degree) meteorological data from the NASA GMAO GEOS-3 assimilation system for 2001 and 2002. We also experimentally analyzed size- and time-resolved aerosol samples at Lassen National Park and Trinity Alps in the spring of 2002, which were taken as part of NOAA's ITCT 2k2 measurement campaign. The model-predicted time-series of soil dust over Northern California agrees remarkably well with our measurements, with a strong temporal correlation between the observations and intercontinental transport of dust across the Pacific in the model. Hence, we conclude that the majority of dust we sampled in Northern California in spring 2002, with aerodynamic diameters of 0.56-5 microns, is from long-range intercontinental transport across the Pacific. The strong correlations also strongly validate atmospheric transport in the IMPACT model over the Northern Pacific in spring.
Information content of long-range NMR data for the characterization of conformational heterogeneity
Energy Technology Data Exchange (ETDEWEB)
Andrałojć, Witold [University of Florence, Center for Magnetic Resonance (CERM) (Italy); Berlin, Konstantin; Fushman, David, E-mail: fushman@umd.edu [University of Maryland, Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization (United States); Luchinat, Claudio, E-mail: luchinat@cerm.unifi.it; Parigi, Giacomo; Ravera, Enrico [University of Florence, Center for Magnetic Resonance (CERM) (Italy); Sgheri, Luca [CNR, Istituto per le Applicazioni del Calcolo, Sezione di Firenze (Italy)
2015-07-15
Long-range NMR data, namely residual dipolar couplings (RDCs) from external alignment and paramagnetic data, are becoming increasingly popular for the characterization of conformational heterogeneity of multidomain biomacromolecules and protein complexes. The question addressed here is how much information is contained in these averaged data. We have analyzed and compared the information content of conformationally averaged RDCs caused by steric alignment and of both RDCs and pseudocontact shifts caused by paramagnetic alignment, and found that, despite the substantial differences, they contain a similar amount of information. Furthermore, using several synthetic tests we find that both sets of data are equally good towards recovering the major state(s) in conformational distributions.
Long range anticorrelations and non-gaussian behavior of a leaky faucet
Penna, T J P; Sartorelli, J C; Gonçalves, W M; Pinto, R D
1995-01-01
We find that intervals between successive drops from a leaky faucet display scale-invariant, long-range anticorrelations characterized by the same exponents of heart beat-to-beat intervals of healthy subjects. This behavior is also confirmed by numerical simulations on lattice and it is faucet-width- and flow-rate-independent. The histogram for the drop intervals is also well described by a L\\'evy distribution with the same index for both histograms of healthy and diseased subjects. This additional result corroborates the evidence for similarities between leaky faucets and healthy hearts underlying dynamics.
Ultralong-range order in the Fermi-Hubbard model with long-range interactions
van Loon, Erik G. C. P.; Katsnelson, Mikhail I.; Lemeshko, Mikhail
2015-08-01
We use the dual boson approach to reveal the phase diagram of the Fermi-Hubbard model with long-range dipole-dipole interactions. By using a large-scale finite-temperature calculation on a 64 ×64 square lattice we demonstrate the existence of a novel phase, possessing an "ultralong-range" order. The fingerprint of this phase—the density correlation function—features a nontrivial behavior on a scale of tens of lattice sites. We study the properties and the stability of the ultralong-range-ordered phase, and show that it is accessible in modern experiments with ultracold polar molecules and magnetic atoms.
Constraints on flavor-dependent long range forces from neutrino experiments
Bandyopadhyay, A; Joshipura, A S; Bandyopadhyay, Abhijit; Dighe, Amol; Joshipura, Anjan S.
2006-01-01
We study the impact of flavor-dependent long range leptonic forces mediated by the $L_e-L_\\mu$ or $L_e -L_\\tau$ gauge bosons on the solar neutrino oscillations, when the interaction range $R_{LR}$ is much larger than the Earth-Sun distance. The solar and atmospheric neutrino mass scales do not get trivially decoupled in this situation even if $\\theta_{13}$ is vanishingly small. In addition, for $\\alpha \\gsim 10^{-52}$ and normal hierarchy, resonant enhancement of $\\theta_{13}$ may give rise to strong energy dependent effects on the $\
Peroxy radicals and ozone photochemistry in air masses undergoing long-range transport
Directory of Open Access Journals (Sweden)
A. E. Parker
2009-09-01
Full Text Available Concentrations of peroxy radicals (HO_{2}+Σ_{i}R_{i}O_{2} in addition to other trace gases were measured onboard the UK Meteorological Office/Natural Environment Research Council British Aerospace 146-300 atmospheric research aircraft during the Intercontinental Transport of Ozone and Precursors (ITOP campaign based at Horta Airport, Faial, Azores (38.58° N, 28.72° W in July/August 2004. The overall peroxy radical altitude profile displays an increase with altitude that is likely to have been impacted by the effects of long-range transport. The peroxy radical altitude profile for air classified as of marine origin shows no discernable altitude profile. A range of air-masses were intercepted with varying source signatures, including those with aged American and Asian signatures, air-masses of biomass burning origin, and those that originated from the east coast of the United States. Enhanced peroxy radical concentrations have been observed within this range of air-masses indicating that long-range transported air-masses traversing the Atlantic show significant photochemical activity. The net ozone production at clear sky limit is in general negative, and as such the summer mid-Atlantic troposphere is at limit net ozone destructive. However, there is clear evidence of positive ozone production even at clear sky limit within air masses undergoing long-range transport, and during ITOP especially between 5 and 5.5 km, which in the main corresponds to a flight that extensively sampled air with a biomass burning signature. Ozone production was NO_{x} limited throughout ITOP, as evidenced by a good correlation (r^{2}=0.72 between P(O_{3} and NO. Strong positive net ozone production has also been seen in varying source signature air-masses undergoing long-range transport, including but not limited to low-level export events, and export from the east coast of the United States.
Self-Organization of Wireless Ad Hoc Networks as Small Worlds Using Long Range Directional Beams
Banerjee, Abhik; Gauthier, Vincent; Yeo, Chai Kiat; Afifi, Hossam; Lee, Bu Sung
2011-01-01
We study how long range directional beams can be used for self-organization of a wireless network to exhibit small world properties. Using simulation results for randomized beamforming as a guideline, we identify crucial design issues for algorithm design. Subsequently, we propose an algorithm for deterministic creation of small worlds. We define a new centrality measure that estimates the structural importance of nodes based on traffic flow in the network, which is used to identify the optimum nodes for beamforming. This results in significant reduction in path length while maintaining connectivity.
Long-range order for the spin-1 Heisenberg model with a small antiferromagnetic interaction
Energy Technology Data Exchange (ETDEWEB)
Lees, Benjamin, E-mail: b.lees@warwick.ac.uk [Department of Mathematics, University of Warwick, Coventry CV4 7AL (United Kingdom)
2014-09-15
We look at the general SU(2) invariant spin-1 Heisenberg model. This family includes the well-known Heisenberg ferromagnet and antiferromagnet as well as the interesting nematic (biquadratic) and the largely mysterious staggered-nematic interaction. Long range order is proved using the method of reflection positivity and infrared bounds on a purely nematic interaction. This is achieved through the use of a type of matrix representation of the interaction making clear several identities that would not otherwise be noticed. Using the reflection positivity of the antiferromagnetic interaction one can then show that the result is maintained if we also include an antiferromagnetic interaction that is sufficiently small.
Quantum Spin Dynamics with Pairwise-Tunable, Long-Range Interactions
2016-08-05
Quantum Inf Comput 3(1):15–37. 64. Berry DW, Ahokas G, Cleve R, Sanders BC (2007) Efficient quantum algorithms for simulating sparse Hamiltonians. Commun... Quantum spin dynamics with pairwise-tunable, long-range interactions C.-L. Hunga,b,1,2, Alejandro González-Tudelac,1,2, J. Ignacio Ciracc, and H. J...Kimblec,d,e,2 aDepartment of Physics and Astronomy, Purdue University, West Lafayette, IN 47907; bPurdue Quantum Center, Purdue University, West
Long-range magnetic ordering in Na2IrO3
Liu, X.; Berlijn, T.; Yin, W.-G.; Ku, W.; Tsvelik, A.; Kim, Young-June; Gretarsson, H.; Singh, Yogesh; Gegenwart, P.; Hill, J. P.
2011-06-01
We report a combined experimental and theoretical investigation of the magnetic structure of the honeycomb-lattice magnet Na2IrO3, a candidate for a realization of a gapless spin liquid. Using resonant x-ray magnetic scattering at the Ir L3 edge, we find three-dimensional long-range antiferromagnetic order below TN=13.3 K. From the azimuthal dependence of the magnetic Bragg peak, the ordered moment is determined to be predominantly along the a axis. Combining the experimental data with first-principles calculations, we propose that the most likely spin structure is a zig-zag structure.
Molecular dynamics for long-range interacting systems on Graphic Processing Units
Filho, Tarcísio M Rocha
2012-01-01
We present implementations of a fourth-order symplectic integrator on graphic processing units for three $N$-body models with long-range interactions of general interest: the Hamiltonian Mean Field, Ring and two-dimensional self-gravitating models. We discuss the algorithms, speedups and errors using one and two GPU units. Speedups can be as high as 140 compared to a serial code, and the overall relative error in the total energy is of the same order of magnitude as for the CPU code. The number of particles used in the tests range from 10,000 to 50,000,000 depending on the model.
Mourragui, Mustapha
2011-01-01
We consider a boundary driven exclusion process associated to particles evolving under Kawasaki (conservative) dynamics and long range interaction in a regime in which at equilibrium phase separation might occur. We show that the empirical density under the diffusive scaling solves a non linear integro differential evolution equation with Dirichlet boundary conditions and we prove the associated dynamical large deviations principle. Further, tuning suitable the intensity of the interaction, in the uniqueness phase regime, we show that under the stationary measure the empirical density solves a non local, stationary, transport equation.
Energy Technology Data Exchange (ETDEWEB)
Heo, Won Nyoung; Lim, Hyung Taik; Kim, Tae Gyung [Department of Physics, Yeungnam University, Gyeongsan (Korea, Republic of); Choi, Myoung Seon [ANSCO, Daejeon (Korea, Republic of)
2012-10-15
Like the phase array based ultrasonic system, complicated electronics has been used for real time signal processing in the magnetostrictive long-range ultrasonic testing(LRUT) system. This study shows that the software approach including the phase compensation, noise filtering and waveform transformation takes advantage rather than the previous hardware approach. Furthermore, it is possible for the software approach to be able more flexible and efficient realtime signal processing. These results will contribute to a cost-effective LRUT system and analysis of the inspection data.
Anomalous effect of turning off long-range mobility interactions in Stokesian Dynamics
Wilson, Adam K Townsend Helen J
2016-01-01
In Stokesian Dynamics, particles are assumed to interact in two ways: through long-range mobility interactions and through short-range lubrication interactions. To speed up computations, in concentrated suspensions it is common to consider only lubrication. We show that, although this approximation provides acceptable results in monodisperse suspensions, in bidisperse suspensions it produces physically unreasonable results - "bunching" - whenever external forces are applied. We suggest that this problem could be mitigated by a careful choice of pairs of particles on which lubrication interactions should be included.
Dynamics of Non- interacting System with Long-Range Correlated Quenched Impurities
Institute of Scientific and Technical Information of China (English)
CHEN Yuan
2003-01-01
The theoretic renormalization group approach is applied to the study of the critical behavior of non-interacting system with long-range correlated quenched impurities, which has a power-like correlations r-(d-ρ). Totwo-loop order, the asymptotic scaling laws and the critical exponents are studied in the frame of a double (ε, ρ)expansion with ρ of order ε = 4 - d. In d ＜ 4, it is argued that the initial slip exponent θ = 0 together with the dynamicexponent z ＜ 2 is exact in this kind of random system.
Energy Technology Data Exchange (ETDEWEB)
Catechis, Christopher Spyros
2013-02-01
The property subject to this Environmental Baseline Survey (EBS) is located at the Oliktok Long Range Radar Station (LRRS). The Oliktok LRRS is located at 70À 30 W latitude, 149À 53 W longitude. It is situated at Oliktok Point on the shore of the Beaufort Sea, east of the Colville River. The purpose of this EBS is to document the nature, magnitude, and extent of any environmental contamination of the property; identify potential environmental contamination liabilities associated with the property; develop sufficient information to assess the health and safety risks; and ensure adequate protection for human health and the environment related to a specific property.
Long-range nematic order and anomalous fluctuations in suspensions of swimming filamentous bacteria
Nishiguchi, Daiki; Nagai, Ken H.; Chaté, Hugues; Sano, Masaki
2017-02-01
We study the collective dynamics of elongated swimmers in a very thin fluid layer by devising long filamentous nontumbling bacteria. The strong confinement induces weak nematic alignment upon collision, which, for large enough density of cells, gives rise to global nematic order. This homogeneous but fluctuating phase, observed on the largest experimentally accessible scale of millimeters, exhibits the properties predicted by standard models for flocking, such as the Vicsek-style model of polar particles with nematic alignment: true long-range nematic order and nontrivial giant number fluctuations.
Long-Range Plasmon Assisted Energy Transfer Between Two Fluorescent Emitters
Bouchet, D; Carminati, R; De Wilde, Y; Krachmalnicoff, V
2016-01-01
We demonstrate plasmon assisted energy transfer between two fluorophores located at distances up to $7\\; \\mu$m on the top of a thin silver film. Thanks to the strong confinement and large propagation length of surface plasmon polaritons, the range of the energy transfer is almost two orders of magnitude larger than the values reported in the literature so far. The parameters driving the energy transfer range are thoroughly characterized and are in very good agreement with theoretically expected values. This work shows the potential of plasmonic structures for efficient long-range energy transfer and opens rich perspectives for the study of collective emission phenomena.
A vertically-coupled liquid-crystal long-range plasmonic optical switch
Zografopoulos, Dimitrios C
2012-01-01
An optical switch based on liquid-crystal tunable long-range metal stripe waveguides is proposed and theoretically investigated. A nematic liquid crystal layer placed between a vertical configuration consisting of two gold stripes is shown to allow for the extensive electro-optic tuning of the coupler's waveguiding characteristics. Rigorous liquid-crystal switching studies are coupled with the investigation of the optical properties of the proposed plasmonic structure, taking into account different excitation conditions and the impact of LC-scattering losses. A directional coupler optical switch is demonstrated, which combines low power consumption, low cross-talk, short coupling lengths, along with sufficiently reduced insertion losses.
DEFF Research Database (Denmark)
Ndukaife, Justus C.; Kildishev, Alexander V.; Nnanna, Agbai George Agwu;
2016-01-01
enables on-demand long-range and rapid delivery of single nano-objects to specific plasmonic nanoantennas, where they can be trapped and even locked in place. We also present a physical model that elucidates the role of both heat-induced fluidic motion and plasmonic field enhancement in the plasmon......-assisted optical trapping process. Finally, by applying a d.c. field or low-frequency a.c. field (below 10 Hz) while the particle is held in the trap by the gradient force, the trapped nano-objects can be immobilized into plasmonic hotspots, thereby providing the potential for effective low-power nanomanufacturing...
Using geometry to manipulate long-range correlation of light inside disordered media
Sarma, Raktim; Neupane, Pauf; Cao, Hui
2015-01-01
We demonstrate experimentally that long-range intensity correlation for light propagating inside random photonic waveguides can be modified by changing the shape of the waveguide. The functional form of spatial correlation is no longer universal in the regime of diffusive transport and becomes shape-dependent due to the non-local nature of wave propagation. The spatial dependence of the correlation may be asymmetric for light incident from opposite ends of the waveguide. This work opens the door to control non-local effects in mesoscopic transport of waves by manipulating the geometry of random systems.
Cluster Monte Carlo and dynamical scaling for long-range interactions
Flores-Sola, Emilio; Kenna, Ralph; Berche, Bertrand
2016-01-01
Many spin systems affected by critical slowing down can be efficiently simulated using cluster algorithms. Where such systems have long-range interactions, suitable formulations can additionally bring down the computational effort for each update from O($N^2$) to O($N\\ln N$) or even O($N$), thus promising an even more dramatic computational speed-up. Here, we review the available algorithms and propose a new and particularly efficient single-cluster variant. The efficiency and dynamical scaling of the available algorithms are investigated for the Ising model with power-law decaying interactions.
Long-range nematic order and anomalous fluctuations in suspensions of swimming filamentous bacteria
Nishiguchi, Daiki; Chaté, Hugues; Sano, Masaki
2016-01-01
We study the collective dynamics of long, filamentous, non-tumbling bacteria swimming in a very thin fluid layer. The strong confinement induces nematic alignment upon collision, which, for large enough density of cells, gives rise to global nematic order. We show that this homogeneous but fluctuating phase, observed on the largest experimentally-accessible scale of millimeters, exhibits the same properties as the Vicsek-style model of polar particles with nematic alignment: true long-range nematic order and non-trivial giant number fluctuations
Multi-particle long-range rapidity correlations from fluctuation of the fireball longitudinal shape
Bzdak, Adam
2015-01-01
We calculate the genuine long-range multi-particle rapidity correlation functions, $C_{n}(y_1,...,y_n)$ for $n=3,4,5,6$, originating from fluctuations of the fireball longitudinal shape. In these correlation functions any contribution from the short-range two-particle correlations, and in general up to $(n-1)$-particle in $C_n$, is suppressed. The information about the fluctuating fireball shape in rapidity is encoded in the cumulants of coefficients of the orthogonal polynomial expansion of particle distributions in rapidity.
Large deviations and occupation times for spin particle systems with long range interactions
Institute of Scientific and Technical Information of China (English)
陈金文
2000-01-01
The large deviation principle for spin particle systems with long range interactions has been studied. It is shown that most of the results in Chen J.W. and Dai Pra P. ’s previous papers can be extended to the present situation. A particularly interesting result is the variational principle which characterizes the stationary Markov measures of such systems as the zeros of the governing LD rate functions. Uniqueness of such measure is studied from this as well as other point of view. We then apply the results to the occupation times of the systems. New large deviation and convergence results are obtained.
Large deviations and occupation times for spin particle systems with long range interactions
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
The large deviation principle for spin particle systems with long range interactions has been studied. It is shown that most of the results in Chen J.W. and Dai Pra P.'s previous papers can be extended to the present situation. A particularly interesting result is the variational principle which characterizes the stationary Markov measures of such systems as the zeros of the governing LD rate functions. Uniqueness of such measure is studied from this as well as other point of view. We then apply the results to the occupation times of the systems. New large deviation and convergence results are obtained.
Mixing and decoherence in continuous-time quantum walks on long-range interacting cycles
Energy Technology Data Exchange (ETDEWEB)
Salimi, S; Radgohar, R [Faculty of Science, Department of Physics, University of Kurdistan, Pasdaran Ave., Sanandaj (Iran, Islamic Republic of)], E-mail: shsalimi@uok.ac.ir, E-mail: r.radgohar@uok.ac.ir
2009-11-27
We study the effect of small decoherence in continuous-time quantum walks on long-range interacting cycles, which are constructed by connecting all the two nodes of distance m on the cycle graph. In our investigation, each node is continuously monitored by an individual point contact, which induces the decoherence process. We obtain the analytical probability distribution and the mixing time upper bound. Our results show that, for small rates of decoherence, the mixing time upper bound is independent of distance parameter m and is proportional to inverse of decoherence rate.
Connection Between Quantum-Classical Correspondence and Long-Range Correlations in Quantum Spectra
Institute of Scientific and Technical Information of China (English)
LI Xi-Guo; SONG Jian-Jun
2004-01-01
@@ Based on the Berry-Tabor trace formula, a semiclassical quantization condition for the periodic orbits in a two dimensional uncoupled oscillator system and the correspondence relation between the quantum levels and classical trajectories of the system have been studied in detail. Making use of the quantum-classical correspondence relation, it has been found that if a set of quantum levels corresponds to the periodic orbits with the same topology structure M ( M1, M2 ), there will be long-range correlations among these quantum levels.
Abnormal Cutoff Thickness of Long-Range Surface Plasmon Polariton Modes Guided by Thin Metal Films
Institute of Scientific and Technical Information of China (English)
LIU Fang; RAO Yi; HUANG Yi-Dong; ZHANG Wei; PENG Jiang-De
2007-01-01
Long-range surface plasmon polariton(LRSPP) modes guided by a thin metal film surrounded by semi-infinite dielectrics with different refractive indices are studied.Our cMculation results show that the cutoff thickness of the metal film does not monotonically increase with refractive index difference △n between the SHbstrate and superstrate.Just because of this abnormal behaviour of cutoff thickness,the existence of LRSPP illustrates complicated situations in asymmetric configurations.For a certain metal film thickness,LRsPP may exist in one.two or three refractive index difference △n regions.
Cell-veto Monte Carlo algorithm for long-range systems
Kapfer, Sebastian C.; Krauth, Werner
2016-09-01
We present a rigorous efficient event-chain Monte Carlo algorithm for long-range interacting particle systems. Using a cell-veto scheme within the factorized Metropolis algorithm, we compute each single-particle move with a fixed number of operations. For slowly decaying potentials such as Coulomb interactions, screening line charges allow us to take into account periodic boundary conditions. We discuss the performance of the cell-veto Monte Carlo algorithm for general inverse-power-law potentials, and illustrate how it provides a new outlook on one of the prominent bottlenecks in large-scale atomistic Monte Carlo simulations.
Atoms in double-delta-kicked periodic potentials: chaos with long-range correlations
Jones, P H; Hur, G; Monteiro, T S
2004-01-01
We report an experimental and theoretical study of the dynamics of cold atoms subjected to closely-spaced pairs of pulses in an optical lattice. The experiments show the interplay between fully coherent quantum dynamics and a novel momentum-diffusion regime: for all previously-studied delta-kicked systems, chaotic classical dynamics shows diffusion with short-time (2 or 3-kick) correlations; here, chaotic diffusion combines with new types of long-ranged 'global' correlations, between all kick-pairs, which control transport through trapping regions in phase-space. Analytical formulae are presented and, with quantum localization, are used to analyse the experiments.
Directory of Open Access Journals (Sweden)
Víctor Sarto i Monteys
Full Text Available BACKGROUND: In the course of evolution butterflies and moths developed two different reproductive behaviors. Whereas butterflies rely on visual stimuli for mate location, moths use the 'female calling plus male seduction' system, in which females release long-range sex pheromones to attract conspecific males. There are few exceptions from this pattern but in all cases known female moths possess sex pheromone glands which apparently have been lost in female butterflies. In the day-flying moth family Castniidae ("butterfly-moths", which includes some important crop pests, no pheromones have been found so far. METHODOLOGY/PRINCIPAL FINDINGS: Using a multidisciplinary approach we described the steps involved in the courtship of P. archon, showing that visual cues are the only ones used for mate location; showed that the morphology and fine structure of the antennae of this moth are strikingly similar to those of butterflies, with male sensilla apparently not suited to detect female-released long range pheromones; showed that its females lack pheromone-producing glands, and identified three compounds as putative male sex pheromone (MSP components of P. archon, released from the proximal halves of male forewings and hindwings. CONCLUSIONS/SIGNIFICANCE: This study provides evidence for the first time in Lepidoptera that females of a moth do not produce any pheromone to attract males, and that mate location is achieved only visually by patrolling males, which may release a pheromone at short distance, putatively a mixture of Z,E-farnesal, E,E-farnesal, and (E,Z-2,13-octadecadienol. The outlined behavior, long thought to be unique to butterflies, is likely to be widespread in Castniidae implying a novel, unparalleled butterfly-like reproductive behavior in moths. This will also have practical implications in applied entomology since it signifies that the monitoring/control of castniid pests should not be based on the use of female-produced pheromones, as
Designing a multicolor long range nanoscopic ruler for the imaging of heterogeneous tumor cells
Chavva, Suhash Reddy; Viraka Nellore, Bhanu Priya; Pramanik, Avijit; Sinha, Sudarson Sekhar; Jones, Stacy; Ray, Paresh Chandra
2016-07-01
Tumor heterogeneity is one of the biggest challenges in cancer treatment and diagnosis. A multicolor optical ruler is essential to address the heterogeneous tumor cell complexity. Driven by this need, the current article reports the design of a multicolor long range nanoscopic ruler for screening tumor heterogeneity by accurately identifying epithelial cells and cancer stem cells (CSCs) simultaneously. A nanoscopic surface energy transfer (NSET) ruler has been developed using blue fluorescence polymer dots (PDs) and red fluorescence gold cluster dots (GCDs) as multicolor fluorescence donor and plasmonic gold nanoparticle (GNP) acts as an excellent acceptor. Reported experimental results demonstrated that the multicolor nanoscopic ruler's working window is above 35 nm distances, which is more than three times farther than that of Förster resonance energy transfer (FRET) distance limit. Theoretical modeling using Förster dipole-dipole coupling and dipole to nanoparticle surface energy transfer have been used to discuss the possible mechanism for multicolor nanoscopic ruler's long-range capability. Using RNA aptamers that are specific for the target cancer cells, experimental data demonstrate that the nanoscopic ruler can be used for screening epithelial and CSCs simultaneously from a whole blood sample with a detection capability of 10 cells per mL. Experimental data show that the nanoscopic ruler can distinguish targeted cells from non-targeted cells.
Quantum phases from competing short- and long-range interactions in an optical lattice.
Landig, Renate; Hruby, Lorenz; Dogra, Nishant; Landini, Manuele; Mottl, Rafael; Donner, Tobias; Esslinger, Tilman
2016-04-28
Insights into complex phenomena in quantum matter can be gained from simulation experiments with ultracold atoms, especially in cases where theoretical characterization is challenging. However, these experiments are mostly limited to short-range collisional interactions; recently observed perturbative effects of long-range interactions were too weak to reach new quantum phases. Here we experimentally realize a bosonic lattice model with competing short- and long-range interactions, and observe the appearance of four distinct quantum phases--a superfluid, a supersolid, a Mott insulator and a charge density wave. Our system is based on an atomic quantum gas trapped in an optical lattice inside a high-finesse optical cavity. The strength of the short-range on-site interactions is controlled by means of the optical lattice depth. The long (infinite)-range interaction potential is mediated by a vacuum mode of the cavity and is independently controlled by tuning the cavity resonance. When probing the phase transition between the Mott insulator and the charge density wave in real time, we observed a behaviour characteristic of a first-order phase transition. Our measurements have accessed a regime for quantum simulation of many-body systems where the physics is determined by the intricate competition between two different types of interactions and the zero point motion of the particles.
Brandenburg, J. G.; Bates, J. E.; Sun, J.; Perdew, J. P.
2016-09-01
The strongly constrained and appropriately normed (SCAN) semilocal density functional [J. Sun, A. Ruzsinszky, and J. P. Perdew, Phys. Rev. Lett. 115, 036402 (2015), 10.1103/PhysRevLett.115.036402] obeys all 17 known exact constraints for meta-generalized-gradient approximations (meta-GGAs), and it includes some medium-range correlation effects. Long-range London dispersion interactions are still missing, but they can be accounted for via an appropriate correction scheme. In this study, we combine SCAN with an efficient London dispersion correction and show that lattice energies of simple organic crystals can be improved with the applied correction by 50%. The London-dispersion corrected SCAN meta-GGA outperforms all other tested London-dispersion corrected meta-GGAs for molecular geometries. Our method yields mean absolute deviations (MADs) for main group bond lengths that are consistently below 1 pm, rotational constants with MADs of 0.2%, and noncovalent distances with MADs below 1%. For a large database of general main group thermochemistry and kinetics (˜800 chemical species), one of the lowest weighted mean absolute deviations for long-range corrected meta-GGA functionals is achieved. Noncovalent interactions are of average quality, and hydrogen bonded systems in particular seem to suffer from overestimated polarization related to the self-interaction error of SCAN. We also discuss some consequences of numerical sensitivity encountered for meta-GGAs.
Energy Technology Data Exchange (ETDEWEB)
Petersen, G. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Hydrophysik
1999-07-01
This paper presents a brief review of the processes by which airborne heavy metals are transported from the main emission areas in Europe and become subject to deposition and absorption into terrestrial and aquatic ecosystems with subsequent transport and transformation within the biotic and abiotic media that comprise these ecosystems. Results from numerical simulation models capable of simulating long-range transport of heavy metals over Europe together with measurement data of heavy metal concentrations in air and precipitation and the corresponding dry and wet deposition fluxes are reported. European wide inventories of anthropogenic heavy metal emissions based on location and capacity of their dominating source categories such as fossil fuel burning in power plants, industrial and residential combustion, waste incineration and road traffic are briefly described. Emission reduction scenarios with respect to introduction of lead free gasoline are outlined. The critical gaps of knowledge on heavy metals in the atmosphere are identified focusing on uncertainties associated with emission fluxes in Eastern Europe and the scarcity of measurement data in that area. Future research is needed to estimate the effects of emission reductions on deposition fluxes of heavy metals to sensitive ecosystems such as forested areas in Europe is recommended. Special emphasis is placed on mercury, lead and cadmium which have been defined within the European convention on long-range transboundary air pollution of the United Nations-Economic Commission Europe (UN-ECE) to be the priority heavy metals of concern. (orig.)
Mechanism of Long-Range Penetration of Low-Energy Ions in Botanic Samples
Institute of Scientific and Technical Information of China (English)
刘峰; 王宇钢; 薛建明; 王思学; 杜广华; 颜莎; 赵渭江
2002-01-01
We present experimental evidence to reveal the mechanism of long-range penetration of low-energy ions in botanic samples. In the 100keV Ar+ ion transmission measurement, the result confirmed that low-energy ions could penetrate at least 60μm thick kidney bean slices with the probability of about 1.0 × 10-5. The energy spectrum of 1 MeV He+ ions penetrating botanic samples has shown that there is a peak of the count of ions with little energy loss. The probability of the low-energy ions penetrating the botanic sample is almost the same as that of the high-energy ions penetrating the same samples with little energy loss. The results indicate that there are some micro-regions with mass thickness less than the projectile range of low-energy ions in the botanic samples and they result in the long-range penetration of low-energy ions in botanic samples.
Investigation of near-axial interference effects in long-range acoustic propagation in the ocean
Grigorieva, Natalie S.; Fridman, Gregory M.
2002-05-01
The observed time-of-arrival patterns from a number of long-range ocean acoustic propagation experiments show early geometrical-like arrivals followed by a crescendo of energy that propagates along the sound-channel axis and is not resolved into individual arrivals. The two-dimensional reference point source problem for the parabolic index of refraction squared is investigated to describe in a simple model case the interference of near-axial waves which resulted in forming the so-called axial wave and propose a formula for the axial wave in more general cases. Using the method proposed by Buldyrev [V. Buldyrev, Tr. Mat. Inst. Steklov 115, 78-102 (1971)], the integral representation for the exact solution is transformed in such a way to extract ray summands corresponding to rays radiated from the source at angles less than a certain angle, the axial wave, and a term corresponding to the sum of all the rays having launch angles greater than the indicated angle. Numerical results for the axial wave and the last term are obtained for parameters corresponding to long-range ocean acoustic propagation experiments. The generalization of the obtained formula for the axial wave to the case of an arbitrary range-independent sound speed is given and discussed. [Work supported by VSP Grant No. N00014-01-4003.
Long-ranged interactions in thin TiN films at the superconductor-insulator transition?
Energy Technology Data Exchange (ETDEWEB)
Kronfeldner, Klaus; Strunk, Christoph [Institute for Experimental and Applied Physics, University of Regensburg (Germany); Baturina, Tatyana [A.V. Rzhanov Institute of Semiconductor Physics SB RAS, Novosibirsk (Russian Federation)
2015-07-01
We measured IV-characteristics and magnetoresistance of square TiN-films in the vicinity of the disorder-tuned superconductor-insulator transition (SIT) for different sizes (5 μm to 240 μm). While the films are superconducting at zero magnetic field, at finite fields a SIT occurs. The resistance shows thermally activated behaviour on both sides of the SIT. Deep in the superconducting regime the activation energy grows linear with the sample size as expected for a size-independent critical current density. Closer to the SIT the activation energy becomes clearly size independent. On the insulating side the magnetoresistance maximum and the activation energy both grow logarithmically with sample size which is consistent with a size-limited charge BKT (Berezinskii-Kosterlitz-Thouless) scenario. In order to test for the presence of long-ranged interactions in our films, we investigate the influence of a topgate. It is expected to screen the possible long-ranged interactions as the distance of the film to the gate is much shorter than the electrostatic screening length deduced from the size-dependent activation energy.
Long Range Dependence Prognostics for Bearing Vibration Intensity Chaotic Time Series
Directory of Open Access Journals (Sweden)
Qing Li
2016-01-01
Full Text Available According to the chaotic features and typical fractional order characteristics of the bearing vibration intensity time series, a forecasting approach based on long range dependence (LRD is proposed. In order to reveal the internal chaotic properties, vibration intensity time series are reconstructed based on chaos theory in phase-space, the delay time is computed with C-C method and the optimal embedding dimension and saturated correlation dimension are calculated via the Grassberger–Procaccia (G-P method, respectively, so that the chaotic characteristics of vibration intensity time series can be jointly determined by the largest Lyapunov exponent and phase plane trajectory of vibration intensity time series, meanwhile, the largest Lyapunov exponent is calculated by the Wolf method and phase plane trajectory is illustrated using Duffing-Holmes Oscillator (DHO. The Hurst exponent and long range dependence prediction method are proposed to verify the typical fractional order features and improve the prediction accuracy of bearing vibration intensity time series, respectively. Experience shows that the vibration intensity time series have chaotic properties and the LRD prediction method is better than the other prediction methods (largest Lyapunov, auto regressive moving average (ARMA and BP neural network (BPNN model in prediction accuracy and prediction performance, which provides a new approach for running tendency predictions for rotating machinery and provide some guidance value to the engineering practice.
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
Based on the 500-hPa geopotential height field series of T106 numerical forecast products, by empirical orthogonal function (EOF) time-space separation, and on the hypotheses of EOF space-models being stable, the EOF time coefficient series were taken as dynamical statistic model variables. The dynamic system reconstruction idea and genetic algorithm were introduced to make the dynamical model parameters optimized, and a nonlinear dynamic statistic model of EOF separating time coefficient series was established. By the model time integral and EOF time-space reconstruction, a medium/long-range forecast of subtropical high was carried out. The results show that the dynamical model forecast and T106 numerical forecast were approximately similar in the short-range forecast (≤5 days), but in the medium/long-range forecast (≥5 days), the forecast results of dynamical model was superior to that of T106 numerical products. A new method and idea were presented for diagnosing and forecasting complicated weathers such as subtropical high, and showed a better application outlook.
Hierarchical structures induce long-range dynamical correlations in written texts.
Alvarez-Lacalle, E; Dorow, B; Eckmann, J-P; Moses, E
2006-05-23
Thoughts and ideas are multidimensional and often concurrent, yet they can be expressed surprisingly well sequentially by the translation into language. This reduction of dimensions occurs naturally but requires memory and necessitates the existence of correlations, e.g., in written text. However, correlations in word appearance decay quickly, while previous observations of long-range correlations using random walk approaches yield little insight on memory or on semantic context. Instead, we study combinations of words that a reader is exposed to within a "window of attention," spanning about 100 words. We define a vector space of such word combinations by looking at words that co-occur within the window of attention, and analyze its structure. Singular value decomposition of the co-occurrence matrix identifies a basis whose vectors correspond to specific topics, or "concepts" that are relevant to the text. As the reader follows a text, the "vector of attention" traces out a trajectory of directions in this "concept space." We find that memory of the direction is retained over long times, forming power-law correlations. The appearance of power laws hints at the existence of an underlying hierarchical network. Indeed, imposing a hierarchy similar to that defined by volumes, chapters, paragraphs, etc. succeeds in creating correlations in a surrogate random text that are identical to those of the original text. We conclude that hierarchical structures in text serve to create long-range correlations, and use the reader's memory in reenacting some of the multidimensionality of the thoughts being expressed.
Structural organization of long-range GABAergic projection system of the hippocampus
Directory of Open Access Journals (Sweden)
Shozo Jinno
2009-07-01
Full Text Available GABA is a key mediator of neural activity in the mammalian central nervous system, and a diverse set of GABAergic neurons utilize GABA as transmitter. It has been widely accepted that GABAergic neurons typically serve as interneurons while glutamatergic principal cells send excitatory signals to remote areas. In general, glutamatergic projection neurons monosynaptically innervate both principal cells and local GABAergic interneurons in each target area, and these GABAergic cells play a vital role in modulation of the activity of principal cells. The formation and recall of sensory, motor and cognitive representations require coordinated fast communication among multiple areas of the cerebral cortex, which are thought to be mostly mediated by glutamatergic neurons. However, there is an increasing body of evidence showing that specific subpopulations of cortical GABAergic neurons send long-range axonal projections to subcortical and other cortical areas. In particular, a variety of GABAergic neurons in the hippocampus project to neighboring and remote areas. Using anatomical, molecular and electrophysiological approaches, several types of GABAergic projection neurons have been shown to exist in the hippocampus. The target areas of these cells are the subiculum and other retrohippocampal areas, the medial septum and the contralateral dentate gyrus. The long-range GABAergic projection system of the hippocampus may serve to coordinate precisely the multiple activity patterns of widespread cortical cell assemblies in different brain states and among multiple functionally related areas.
Many-body localization in Ising models with random long-range interactions
Li, Haoyuan; Wang, Jia; Liu, Xia-Ji; Hu, Hui
2016-12-01
We theoretically investigate the many-body localization phase transition in a one-dimensional Ising spin chain with random long-range spin-spin interactions, Vi j∝|i-j |-α , where the exponent of the interaction range α can be tuned from zero to infinitely large. By using exact diagonalization, we calculate the half-chain entanglement entropy and the energy spectral statistics and use them to characterize the phase transition towards the many-body localization phase at infinite temperature and at sufficiently large disorder strength. We perform finite-size scaling to extract the critical disorder strength and the critical exponent of the divergent localization length. With increasing α , the critical exponent experiences a sharp increase at about αc≃1.2 and then gradually decreases to a value found earlier in a disordered short-ranged interacting spin chain. For α localized and the increase in the disorder strength may drive a transition between two many-body localized phases. In contrast, for α >αc , the transition is from a thermalized phase to the many-body localization phase. Our predictions could be experimentally tested with an ion-trap quantum emulator with programmable random long-range interactions, or with randomly distributed Rydberg atoms or polar molecules in lattices.
Long-range surface plasmon polaritons at THz frequencies in thin semiconductor layers
Institute of Scientific and Technical Information of China (English)
Yichen Zhang; Audrey Berrier; Jaime Gómez Rivas
2011-01-01
Surface plasmon polaritons (SPPs) are electromagnetic waves coupled to the free charge carriers at the interface between a metal and a dielectric[1].These waves propagate along the interface,while decaying evanescently away from it.The propagation length of SPPs is mainly limited by Ohmic losses in the metal.A possible way to lower these losses is to reduce the penetration of the electromagnetic field inside the metal,which can be achieved by coupling the SPPs at the opposite sides of a thin metallic film.These coupled SPPs are known as long-range surface plasmon polaritons (LRSPPs) and have been thoroughly investigated at optical frequencies in thin layers of noble metals[2].%We present a theoretical investigation of THz long-range surface plasmon polaritons propagating on thin layers of InSb. The metallic behavior of doped semiconductors at THz frequencies allows the excitation of surface plasmon polaritons with propagation and confinement lengths that can be actively controlled. This control is achieved by acting on the free carrier density, which can be realized by changing the temperature of InSb.
Constraints from Solar and Reactor Neutrinos on Unparticle Long-Range Forces
González-Garciá, M C; Funchal, R Zukanovich
2008-01-01
We have investigated the impact of long-range forces induced by unparticle operators of scalar, vector and tensor nature coupled to fermions in the interpretation of solar neutrinos and KamLAND data. If the unparticle couplings to the neutrinos are mildly non-universal, such long-range forces will not factorize out in the neutrino flavour evolution. As a consequence large deviations from the observed standard matter-induced oscillation pattern for solar neutrinos would be generated. In this case,severe limits can be set on the infrared fix point scale, $\\Lambda_u$, and the new physics scale, $M$, as a function of the ultraviolet ($d_{\\rm UV}$) and anomalous ($d$) dimension of the unparticle operator. For a scalar unparticle, for instance, assuming the non-universality of the lepton couplings to unparticles to be of the order of a few per mil we find that, for $d_{\\rm UV}=3$ and $d=1.1$, $M$ is constrained to be $M> 10^{9}$ TeV ($M> 10^{10}$ TeV) if $\\Lambda_u =$ 1 TeV (10 TeV). For given values of $\\Lambda_u$...
Nonperturbative linked-cluster expansions in long-range ordered quantum systems
Ixert, Dominik; Schmidt, Kai Phillip
2016-11-01
We introduce a generic scheme to perform nonperturbative linked cluster expansions in long-range ordered quantum phases. Clusters are considered to be surrounded by an ordered reference state leading to effective edge fields in the exact diagonalization on clusters, which break the associated symmetry of the ordered phase. Two approaches, based either on a self-consistent solution of the order parameter or on minimal sensitivity with respect to the ground-state energy per site, are formulated to find the optimal edge field in each NLCE order. Furthermore, we investigate the scaling behavior of the NLCE data sequences towards the infinite-order limit. We apply our scheme to gapped and gapless ordered phases of XXZ Heisenberg models on various lattices and for spins 1/2 and 1 using several types of cluster expansions ranging from a full-graph decomposition, rectangular clusters, up to more symmetric square clusters. It is found that the inclusion of edge fields allows to regularize nonperturbative linked-cluster expansions in ordered phases yielding convergent data sequences. This includes the long-range spin-ordered ground state of the spin-1/2 and spin-1 Heisenberg model on the square and triangular lattice as well as the trimerized valence bond crystal of the spin-1 Heisenberg model on the kagome lattice.
Institute of Scientific and Technical Information of China (English)
WANG LiRong; MA Jie; JI WeiBang; WANG GuiPing; XIAO LianTuan; JIA SuoTang
2008-01-01
In this paper, an ultra-high resolution photoassociation spectroscopy study on photoassociation of cesium atoms is reported. The cold cesium gas in the mag-neto-optical trap is illuminated by a photoassociation laser with red-tuning as large as 40 cm-1 below the 6S1/2 + 6P3/2 dissociation limit, and the photoassoclation to the excited state ultracold molecule is detected. High signal-to-noise ratio is obtained by using the lock-in detection of the fluorescence from the modulated cold Cs at-oms. The O-g, and O+u, long-range states which correspond to 6S1/2 + 6P3/2 diSsocia-tion limit are present in the photoassociation spectrum. The effective coefficients of leading long-range interactions and the corresponding vibrational quantum num-ber are obtained using LeRoy-Bernstein Law. It is found that photoassociation process creates rotating molecules and the high J value is a hint that higher partial waves participate in the PA process in the presence of trapping laser.
Hydrogen-mediated long-range magnetic ordering in Pd-rich alloy film
Energy Technology Data Exchange (ETDEWEB)
Lin, Wen-Chin, E-mail: wclin@ntnu.edu.tw; Tsai, Cheng-Jui; Huang, Han-Yuan; Mudinepalli, Venkata Ramana; Chiu, Hsiang-Chih [Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan (China); Wang, Bo-Yao, E-mail: bywang1735@cc.ncue.edu.tw [Department of Physics, National Changhua University of Education, Changhua 500, Taiwan (China)
2015-01-05
The effect of hydrogenation on a 14 nm Co{sub 14}Pd{sub 86}/Al{sub 2}O{sub 3}(0001) thin film was investigated on the basis of the magnetooptical Kerr effect. After exposure to H{sub 2} gas, the squareness of the hysteresis loop showed a large transition from approximately 10% to 100% and the saturation Kerr signal was reduced to nearly 30% of the pristine value. The reversibility of the transition was verified and the response time was within 2–3 s. These observations indicate that the hydride formation transformed the short-range coupled and disordered magnetic state of the Co{sub 14}Pd{sub 86} film to a long-range-ordered ferromagnetic state and induced appreciable decrease in the magnetic moment. The enhanced long-range-ordering and the reduction of the magnetic moment were attributed to the change of electronic structure in Co{sub 14}Pd{sub 86} with hydrogen uptake.
Long-range charge-density-wave proximity effect at cuprate/manganate interfaces
Frano, A.; Blanco-Canosa, S.; Schierle, E.; Lu, Y.; Wu, M.; Bluschke, M.; Minola, M.; Christiani, G.; Habermeier, H. U.; Logvenov, G.; Wang, Y.; van Aken, P. A.; Benckiser, E.; Weschke, E.; Le Tacon, M.; Keimer, B.
2016-08-01
The interplay between charge density waves (CDWs) and high-temperature superconductivity is currently under intense investigation. Experimental research on this issue is difficult because CDW formation in bulk copper oxides is strongly influenced by random disorder, and a long-range-ordered CDW state in high magnetic fields is difficult to access with spectroscopic and diffraction probes. Here we use resonant X-ray scattering in zero magnetic field to show that interfaces with the metallic ferromagnet La2/3Ca1/3MnO3 greatly enhance CDW formation in the optimally doped high-temperature superconductor YBa2Cu3O6+δ (δ ~ 1), and that this effect persists over several tens of nanometres. The wavevector of the incommensurate CDW serves as an internal calibration standard of the charge carrier concentration, which allows us to rule out any significant influence of oxygen non-stoichiometry, and to attribute the observed phenomenon to a genuine electronic proximity effect. Long-range proximity effects induced by heterointerfaces thus offer a powerful method to stabilize the charge-density-wave state in the cuprates and, more generally, to manipulate the interplay between different collective phenomena in metal oxides.
Selective measurements of long-range homonuclear J-couplings in solid-state NMR.
Thureau, Pierre; Mollica, Giulia; Ziarelli, Fabio; Viel, Stéphane
2013-06-01
We demonstrate here that the principle of frequency-selective spin-echoes can be extended to the measurements of long-range homonuclear scalar J-couplings in the solid-state. Singly or doubly frequency-selective pulses were used to generate either a J-modulated experiment (S) or a reference experiment (S0). The combination of these two distinct experiments provides experimental data that, in favorable cases, are insensitive to incoherent relaxation effects, and which can be used to estimate long-range homonuclear J-couplings in multiple spin-systems. The concept is illustrated in the case of a uniformly (13)C and (15)N labeled sample of L-histidine, where the absolute value of homonuclear J-couplings between two spins separated by one, two or three covalent bonds are measured. Moreover, we show that a (2)J((15)N-C-(15)N) coupling as small as 0.9 Hz can be precisely measured with the method presented here.
Testing accuracy of long-range ultrasonic sensors for olive tree canopy measurements.
Gamarra-Diezma, Juan Luis; Miranda-Fuentes, Antonio; Llorens, Jordi; Cuenca, Andrés; Blanco-Roldán, Gregorio L; Rodríguez-Lizana, Antonio
2015-01-28
Ultrasonic sensors are often used to adjust spray volume by allowing the calculation of the crown volume of tree crops. The special conditions of the olive tree require the use of long-range sensors, which are less accurate and faster than the most commonly used sensors. The main objectives of the study were to determine the suitability of the sensor in terms of sound cone determination, angle errors, crosstalk errors and field measurements. Different laboratory tests were performed to check the suitability of a commercial long-range ultrasonic sensor, as were the experimental determination of the sound cone diameter at several distances for several target materials, the determination of the influence of the angle of incidence of the sound wave on the target and distance on the accuracy of measurements for several materials and the determination of the importance of the errors due to interference between sensors for different sensor spacings and distances for two different materials. Furthermore, sensor accuracy was tested under real field conditions. The results show that the studied sensor is appropriate for olive trees because the sound cone is narrower for an olive tree than for the other studied materials, the olive tree canopy does not have a large influence on the sensor accuracy with respect to distance and angle, the interference errors are insignificant for high sensor spacings and the sensor's field distance measurements were deemed sufficiently accurate.
Short- and long-range corrected hybrid density functionals with the D3 dispersion corrections
Wang, Chih-Wei; Chai, Jeng-Da
2016-01-01
We propose a short- and long-range corrected (SLC) hybrid scheme employing 100% Hartree-Fock (HF) exchange at both zero and infinite interelectronic distances, wherein three SLC hybrid density functionals with the D3 dispersion corrections (SLC-LDA-D3, SLC-PBE-D3, and SLC-B97-D3) are developed. SLC-PBE-D3 and SLC-B97-D3 are shown to be accurate for a very diverse range of applications, such as core ionization and excitation energies, thermochemistry, kinetics, noncovalent interactions, dissociation of symmetric radical cations, vertical ionization potentials, vertical electron affinities, fundamental gaps, and valence, Rydberg, and long-range charge-transfer excitation energies. Relative to omegaB97X-D, SLC-B97-D3 provides significant improvement for core ionization and excitation energies and noticeable improvement for the self-interaction, asymptote, energy-gap, and charge-transfer problems, while performing similarly for thermochemistry, kinetics, and noncovalent interactions.
Chen, Zhenyu
2016-12-01
Measurements of two-particle angular correlations in pp collisions at √{ s} = 7 TeV are presented as a function of charged-particle multiplicities. The data, corresponding to an integrated luminosity of about 6.2 pb-1, were collected during the 2010 LHC pp run using the CMS detector. In high-multiplicity events, a long-range (| Δη | > 2), near-side (Δϕ ≈ 0) structure is found in the two-particle Δη - Δϕ correlation functions. The second-order (v2) and third-order (v3) azimuthal anisotropy harmonics of charged particles, KS0 and Λ / Λ ‾ particles are extracted from long-range two-particle correlations as a function of particle multiplicity and transverse momentum, after correcting for the contribution of back-to-back jet correlations. A v2 and v3 value of about 4% and 1%, averaging over 0.3
An Alternative High Luminosity LHC with Flat Optics and Long-Range Beam-Beam Compensation
AUTHOR|(CDS)2070952; Valishev, Aleksander; Shatilov, Dmitry
2015-01-01
In the baseline scenario of the High-Luminosity LHC (HL-LHC), the geometric loss of luminosity in the two high luminosity experiments due to collisions with a large crossing angle is recovered by tilting the bunches in the interaction region with the use of crab cavities. A possible backup scenario would rely on a reduced crossing angle together with flat optics (with different horizontal and vertical β∗ values) for the preservation of luminosity performance. However, the reduction of crossing angle coupled with the flat optics significantly enhances the strength of long-range beam-beam interactions. This paper discusses the possibility to mitigate the long-range beam-beam effects by current bearing wire compensators (or e-lens). We develop a new HL-LHC parameter list and analyze it in terms of integrated luminosity performance as compared to the baseline. Further, we evaluate the operational scenarios using numerical simulations of single-particle dynamics with beam-beam effects.
Impact of long-range desert dust transport on hydrometeor formation over coastal East Asia
Zhang, Zhenxi; Zhou, Wen; Wenig, Mark; Yang, Liangui
2017-01-01
Model simulations and hydrological reanalysis data for 2007 are applied to investigate the impact of long-range desert dust transport on hydrometeor formation over coastal East Asia. Results are analyzed from Hong Kong and Shanghai, which are two representative coastal cities of East Asia. Long-range desert dust transport impacts mainly spring and summer clouds and precipitation over coastal East Asia. In spring, clouds and precipitation come mainly from large-scale condensation and are impacted mainly by dust from the Gobi, Sahara, and Thar deserts. These desert dusts can participate in the precipitation within and below the clouds. At lower latitudes, the dust particles act mainly as water nuclei. At higher latitudes, they act as both water nuclei and ice nuclei. The effect of Gobi, Sahara, and Thar dust on large-scale clouds and precipitation becomes stronger at higher latitudes. In summer, clouds and precipitation over coastal East Asia come mainly from convection and are impacted mainly by dust from the Taklamakan, Arabian, and Karakum-Kavir deserts. Most Taklamakan dust particles can participate in precipitation within convective clouds as ice nuclei, while Arabian and Karakum-Kavir dust particles participate only as water nuclei in precipitation below the clouds. The effect of Taklamakan dust on convective clouds and precipitation becomes stronger at lower latitudes. Of all the desert dusts, that from the Gobi and Taklamakan deserts has the relatively largest impact. Gobi dust impacts climate change in coastal East Asia by affecting spring water clouds at higher latitudes.
Long-range charge-density-wave proximity effect at cuprate/manganate interfaces.
Frano, A; Blanco-Canosa, S; Schierle, E; Lu, Y; Wu, M; Bluschke, M; Minola, M; Christiani, G; Habermeier, H U; Logvenov, G; Wang, Y; van Aken, P A; Benckiser, E; Weschke, E; Le Tacon, M; Keimer, B
2016-08-01
The interplay between charge density waves (CDWs) and high-temperature superconductivity is currently under intense investigation. Experimental research on this issue is difficult because CDW formation in bulk copper oxides is strongly influenced by random disorder, and a long-range-ordered CDW state in high magnetic fields is difficult to access with spectroscopic and diffraction probes. Here we use resonant X-ray scattering in zero magnetic field to show that interfaces with the metallic ferromagnet La2/3Ca1/3MnO3 greatly enhance CDW formation in the optimally doped high-temperature superconductor YBa2Cu3O6+δ (δ ∼ 1), and that this effect persists over several tens of nanometres. The wavevector of the incommensurate CDW serves as an internal calibration standard of the charge carrier concentration, which allows us to rule out any significant influence of oxygen non-stoichiometry, and to attribute the observed phenomenon to a genuine electronic proximity effect. Long-range proximity effects induced by heterointerfaces thus offer a powerful method to stabilize the charge-density-wave state in the cuprates and, more generally, to manipulate the interplay between different collective phenomena in metal oxides.
ANL site response for the DOE FY1994 information resources management long-range plan
Energy Technology Data Exchange (ETDEWEB)
Boxberger, L.M.
1992-03-01
Argonne National Laboratory's ANL Site Response for the DOE FY1994 Information Resources Management (IRM) Long-Range Plan (ANL/TM 500) is one of many contributions to the DOE information resources management long-range planning process and, as such, is an integral part of the DOE policy and program planning system. The Laboratory has constructed this response according to instructions in a Call issued in September 1991 by the DOE Office of IRM Policy, Plans and Oversight. As one of a continuing series, this Site Response is an update and extension of the Laboratory's previous submissions. The response contains both narrative and tabular material. It covers an eight-year period consisting of the base year (FY1991), the current year (FY1992), the budget year (FY1993), the plan year (FY1994), and the out years (FY1995-FY1998). This Site Response was compiled by Argonne National Laboratory's Computing and Telecommunications Division (CTD), which has the responsibility to provide leadership in optimizing computing and information services and disseminating computer-related technologies throughout the Laboratory. The Site Response consists of 5 parts: (1) a site overview, describes the ANL mission, overall organization structure, the strategic approach to meet information resource needs, the planning process, major issues and points of contact. (2) a software plan for DOE contractors, Part 2B, Software Plan FMS plan for DOE organizations, (3) computing resources telecommunications, (4) telecommunications, (5) printing and publishing.
ANL site response for the DOE FY1994 information resources management long-range plan
Energy Technology Data Exchange (ETDEWEB)
Boxberger, L.M.
1992-03-01
Argonne National Laboratory`s ANL Site Response for the DOE FY1994 Information Resources Management (IRM) Long-Range Plan (ANL/TM 500) is one of many contributions to the DOE information resources management long-range planning process and, as such, is an integral part of the DOE policy and program planning system. The Laboratory has constructed this response according to instructions in a Call issued in September 1991 by the DOE Office of IRM Policy, Plans and Oversight. As one of a continuing series, this Site Response is an update and extension of the Laboratory`s previous submissions. The response contains both narrative and tabular material. It covers an eight-year period consisting of the base year (FY1991), the current year (FY1992), the budget year (FY1993), the plan year (FY1994), and the out years (FY1995-FY1998). This Site Response was compiled by Argonne National Laboratory`s Computing and Telecommunications Division (CTD), which has the responsibility to provide leadership in optimizing computing and information services and disseminating computer-related technologies throughout the Laboratory. The Site Response consists of 5 parts: (1) a site overview, describes the ANL mission, overall organization structure, the strategic approach to meet information resource needs, the planning process, major issues and points of contact. (2) a software plan for DOE contractors, Part 2B, ``Software Plan FMS plan for DOE organizations, (3) computing resources telecommunications, (4) telecommunications, (5) printing and publishing.
Griffiths phase and long-range correlations in a biologically motivated visual cortex model
Girardi-Schappo, M.; Bortolotto, G. S.; Gonsalves, J. J.; Pinto, L. T.; Tragtenberg, M. H. R.
2016-07-01
Activity in the brain propagates as waves of firing neurons, namely avalanches. These waves’ size and duration distributions have been experimentally shown to display a stable power-law profile, long-range correlations and 1/f b power spectrum in vivo and in vitro. We study an avalanching biologically motivated model of mammals visual cortex and find an extended critical-like region – a Griffiths phase – characterized by divergent susceptibility and zero order parameter. This phase lies close to the expected experimental value of the excitatory postsynaptic potential in the cortex suggesting that critical be-havior may be found in the visual system. Avalanches are not perfectly power-law distributed, but it is possible to collapse the distributions and define a cutoff avalanche size that diverges as the network size is increased inside the critical region. The avalanches present long-range correlations and 1/f b power spectrum, matching experiments. The phase transition is analytically determined by a mean-field approximation.
Testing Accuracy of Long-Range Ultrasonic Sensors for Olive Tree Canopy Measurements
Directory of Open Access Journals (Sweden)
Juan Luis Gamarra-Diezma
2015-01-01
Full Text Available Ultrasonic sensors are often used to adjust spray volume by allowing the calculation of the crown volume of tree crops. The special conditions of the olive tree require the use of long-range sensors, which are less accurate and faster than the most commonly used sensors. The main objectives of the study were to determine the suitability of the sensor in terms of sound cone determination, angle errors, crosstalk errors and field measurements. Different laboratory tests were performed to check the suitability of a commercial long-range ultrasonic sensor, as were the experimental determination of the sound cone diameter at several distances for several target materials, the determination of the influence of the angle of incidence of the sound wave on the target and distance on the accuracy of measurements for several materials and the determination of the importance of the errors due to interference between sensors for different sensor spacings and distances for two different materials. Furthermore, sensor accuracy was tested under real field conditions. The results show that the studied sensor is appropriate for olive trees because the sound cone is narrower for an olive tree than for the other studied materials, the olive tree canopy does not have a large influence on the sensor accuracy with respect to distance and angle, the interference errors are insignificant for high sensor spacings and the sensor’s field distance measurements were deemed sufficiently accurate.
Vision-Based Long-Range 3D Tracking, applied to Underground Surveying Tasks
Mossel, Annette; Gerstweiler, Georg; Vonach, Emanuel; Kaufmann, Hannes; Chmelina, Klaus
2014-04-01
To address the need of highly automated positioning systems in underground construction, we present a long-range 3D tracking system based on infrared optical markers. It provides continuous 3D position estimation of static or kinematic targets with low latency over a tracking volume of 12 m x 8 m x 70 m (width x height x depth). Over the entire volume, relative 3D point accuracy with a maximal deviation ≤ 22 mm is ensured with possible target rotations of yaw, pitch = 0 - 45° and roll = 0 - 360°. No preliminary sighting of target(s) is necessary since the system automatically locks onto a target without user intervention and autonomously starts tracking as soon as a target is within the view of the system. The proposed system needs a minimal hardware setup, consisting of two machine vision cameras and a standard workstation for data processing. This allows for quick installation with minimal disturbance of construction work. The data processing pipeline ensures camera calibration and tracking during on-going underground activities. Tests in real underground scenarios prove the system's capabilities to act as 3D position measurement platform for multiple underground tasks that require long range, low latency and high accuracy. Those tasks include simultaneously tracking of personnel, machines or robots.
An Alternative High Luminosity LHC with Flat Optics and Long-Range Beam-Beam Compensation
Energy Technology Data Exchange (ETDEWEB)
Fartoukh, Stephane [CERN; Valishev, Alexander [Fermilab; Shatilov, Dmitry [BINP, Novosibirsk
2015-06-01
In the baseline scenario of the High-Luminosity LHC (HL-LHC), the geometric loss of luminosity in the two high luminosity experiments due to collisions with a large crossing angle is recovered by tilting the bunches in the interaction region with the use of crab cavities. A possible backup scenario would rely on a reduced crossing angle together with flat optics (with different horizontal and vertical $\\beta^{\\ast}$values) for the preservation of luminosity performance. However, the reduction of crossing angle coupled with the flat optics significantly enhances the strength of long-range beam-beam interactions. This paper discusses the possibility to mitigate the long-range beam-beam effects by current bearing wire compensators (or e-lens). We develop a new HL-LHC parameter list and analyze it in terms of integrated luminosity performance as compared to the baseline. Further, we evaluate the operational scenarios using numerical simulations of single-particle dynamics with beam-beam effects.
Efficient Methods for Handling Long-Range Forces in Particle-Particle Simulations
Fangohr, H; Cox, S J; De Groot, R A; Daniell, G J; Fangohr, Hans; Price, Andrew R.; Cox, Simon J.; Groot, Peter A.J. de; Daniell, Geoffrey J.
2000-01-01
A number of problems arise when long-range forces, such as those governed by Bessel functions, are used in particle-particle simulations. If a simple cut-off for the interaction is used, the system may find an equilibrium configuration at zero temperature that is not a regular lattice yet has an energy lower than the theoretically predicted minimum for the physical system. We demonstrate two methods to overcome these problems in Monte Carlo and molecular dynamics simulations. The first uses a smoothed potential to truncate the interaction in a single unit cell: this is appropriate for phenomenological characterisations, but may be applied to any potential. The second is a new method for summing the unmodified potential in an infinitely tiled periodic system, which is in excess of 20,000 times faster than previous naive methods which add periodic images in shells of increasing radius: this is suitable for quantitative studies. Finally we show that numerical experiments which do not handle the long-range force ...
Oosterveen, Tony; Kurdija, Sanja; Alekseenko, Zhanna; Uhde, Christopher W; Bergsland, Maria; Sandberg, Magnus; Andersson, Elisabet; Dias, José M; Muhr, Jonas; Ericson, Johan
2012-11-13
Morphogens orchestrate tissue patterning in a concentration-dependent fashion during vertebrate embryogenesis, yet little is known of how positional information provided by such signals is translated into discrete transcriptional outputs. Here we have identified and characterized cis-regulatory modules (CRMs) of genes operating downstream of graded Shh signaling and bifunctional Gli proteins in neural patterning. Unexpectedly, we find that Gli activators have a noninstructive role in long-range patterning and cooperate with SoxB1 proteins to facilitate a largely concentration-independent mode of gene activation. Instead, the opposing Gli-repressor gradient is interpreted at transcriptional levels, and, together with CRM-specific repressive input of homeodomain proteins, comprises a repressive network that translates graded Shh signaling into regional gene expression patterns. Moreover, local and long-range interpretation of Shh signaling differs with respect to CRM context sensitivity and Gli-activator dependence, and we propose that these differences provide insight into how morphogen function may have mechanistically evolved from an initially binary inductive event.
RF Wire Compensator of Long-Range Beam-Beam Effects
Dorda, U; Kroyer, T; Zimmermann, F
2008-01-01
The dynamic aperture of the proton beam circulating in the Large Hadron Collider (LHC) is expected to be limited by up to 120 long-range beam-beam encounters. In order to perfectly compensate the LHC long-range beambeam effect for nominal as well as for so-called "PACMAN" bunches, i.e. bunches at the start or end of a bunch train, the strength of a wire compensator should be adjusted for each bunch individually. Here an RF-based compensator is proposed as a practical solution for the PACMAN compensation. We show that this approach also allows relaxing the power and precision requirements compared with those of a pulsed DC device, to a level within the state-of-the-art of RF technology. Furthermore it permits the use of a passive circulator in the tunnel close to the beam and thus a significant reduction of the transmission line length and of the associated multiple reflections. Simulations of dynamic aperture and emittance growth, issues related to RF phase noise, and first experimental results from laborator...
Kawashima, Yukio; Hirao, Kimihiko
2017-02-24
We introduced two methods to correct the singularity in the calculation of long-range Hartree-Fock (HF) exchange for long-range-corrected density functional theory (LC-DFT) calculations in plane-wave basis sets. The first method introduces an auxiliary function to cancel out the singularity. The second method introduces a truncated long-range Coulomb potential, which has no singularity. We assessed the introduced methods using the LC-BLYP functional by applying it to isolated systems of naphthalene and pyridine. We first compared the total energies and the HOMO energies of the singularity-corrected and uncorrected calculations and confirmed that singularity correction is essential for LC-DFT calculations using plane-wave basis sets. The LC-DFT calculation results converged rapidly with respect to the cell size as the other functionals, and their results were in good agreement with the calculated results obtained using Gaussian basis sets. LC-DFT succeeded in obtaining accurate orbital energies and excitation energies. We next applied LC-DFT with singularity correction methods to the electronic structure calculations of the extended systems, Si and SiC. We confirmed that singularity correction is important for calculations of extended systems as well. The calculation results of the valence and conduction bands by LC-BLYP showed good convergence with respect to the number of k points sampled. The introduced methods succeeded in overcoming the singularity problem in HF exchange calculation. We investigated the effect of the singularity correction on the excitation state calculation and found that careful treatment of the singularities is required compared to ground-state calculations. We finally examined the excitonic effect on the band gap of the extended systems. We calculated the excitation energies to the first excited state of the extended systems using a supercell model at the Γ point and found that the excitonic binding energy, supposed to be small for
Long-Range And Head-On Beam-Beam Compensation Studies in RHIC With Lessons for the LHC
Energy Technology Data Exchange (ETDEWEB)
Fischer, W.; Luo, Y.; Abreu, N.; Calaga, R.; Montag, C.; Robert-Demolaize, G.; /Brookhaven; Dorda, U.; Koutchouk, J.P.; Sterbini, G.; Zimmermann, F.; /CERN; Kim, H.J.; Sen, T.; Shiltsev, V.; Valishev, A.; /Fermilab; Qiang, J.; /LBL, Berkeley; Kabel, A.; /SLAC
2011-11-28
Long-range as well as head-on beam-beam effects are expected to limit the LHC performance with design parameters. They are are also important consideration for the LHC upgrades. To mitigate long-range effects, current carrying wires parallel to the beam were proposed. Two such wires are installed in RHIC where they allow studying the effect of strong long-range beam-beam effects, as well as the compensation of a single long-range interaction. The tests provide benchmark data for simulations and analytical treatments. Electron lenses were proposed for both RHIC and the LHC to reduce the head-on beam-beam effect. We present the experimental long-range beam-beam program at RHIC and report on head-on compensations studies based on simulations.
Guo, Sheng-Bo; Wang, Ying; Yan, Xing; Lin, Longnian; Tsien, Joe; Huang, De-Shuang
The spontaneous in vivo firings of neuron in mouse hippocampus are generally considered as neuronal noise, where there is no any correlation in the inter-spike interval (ISI) sequences. In the present study, we investigate the nature of the ISI sequences of neuron in CA1 area of mouse hippocampus. By using the detrended fluctuation analysis (DFA), we calculated the fluctuation or scaling exponent of the ISI sequences. The results indicated that there exists the long-range power-law correlation over large time scale in the ISI sequences. To further investigate the long-range correlation of ISI, we studied the long-range correlation of ISI sequences from different types of neurons in mouse hippocampus, which are four types of interneurons categorized by their firing patterns. Our results show the presence of long-range correlations in the ISI sequence of different types of neurons. Furthermore, the shuffle surrogate data achieved by randomly shuffle the original ISI sequence is used to verify our conclusion. The application of shuffle surrogate shows that the long-range correlation is destroyed by randomly shuffle, which demonstrates that there is actually the long-range correlation in the ISI sequence. Furthermore, we also compare the long-range correlations of ISI sequence when mice are in different behavioral states, slow-wave sleep (SWS) and active exploration (AE). Our results indicated that the ISI sequences exhibit different extent of long-range correlations: the long-range correlation is significantly stronger when mice are in AE than that of ISI sequence when mice are in SWS, which demonstrated that the varied long-range correlations exhibiting in ISIs of interneurons might be associated with activities of neuronal network regulating the ongoing neuronal activity of different interneurons.
A Study of LoRa: Long Range & Low Power Networks for the Internet of Things
Directory of Open Access Journals (Sweden)
Aloÿs Augustin
2016-09-01
Full Text Available LoRa is a long-range, low-power, low-bitrate, wireless telecommunications system, promoted as an infrastructure solution for the Internet of Things: end-devices use LoRa across a single wireless hop to communicate to gateway(s, connected to the Internet and which act as transparent bridges and relay messages between these end-devices and a central network server. This paper provides an overview of LoRa and an in-depth analysis of its functional components. The physical and data link layer performance is evaluated by field tests and simulations. Based on the analysis and evaluations, some possible solutions for performance enhancements are proposed.
A Hamiltonian for the inclusion of spin effects in long-range Rydberg molecules
Eiles, Matthew T
2016-01-01
The interaction between a Rydberg electron and a neutral atom situated inside its extended orbit is described via contact interactions for each atom-electron scattering channel. In ultracold environments, these interactions lead to ultra-long-range molecular states with binding energies typically ranging from $10$-$10^4$MHz. These energies are comparable to the relativistic and hyperfine structure of the separate atomic components. Studies of molecular formation aiming to reproduce observations with spectroscopic accuracy must therefore include the hyperfine splitting of the neutral atom and the spin-orbit splittings of both the Rydberg atom and the electron-atom interaction. Adiabatic potential energy curves that fully include these additional effects are presented for Rb$_2$ and Cs$_2$. The influence of spin degrees of freedom on the potential energy curves and molecular multipole moments probed in recent experimental work is elucidated and contrasted with other recent theoretical effort in this direction.
New Horizons: Long-Range Kuiper Belt Targets Observed by the Hubble Space Telescope
Benecchi, S. D.; Noll, K. S.; Weaver, H. A.; Spencer, J. R.; Stern, S. A.; Buie, M. W.; Parker, A. H.
2014-01-01
We report on Hubble Space Telescope (HST) observations of three Kuiper Belt Objects (KBOs), discovered in our dedicated ground-based search campaign, that are candidates for long-range observations from the New Horizons spacecraft: 2011 epochY31, 2011 HZ102, and 2013 LU35. Astrometry with HST enables both current and future critical accuracy improvements for orbit precision, required for possible New Horizons observations, beyond what can be obtained from the ground. Photometric colors of all three objects are red, typical of the Cold Classical dynamical population within which they reside; they are also the faintest KBOs to have had their colors measured. None are observed to be binary with HST above separations of approx. 0.02 arcsec (approx. 700 km at 44 AU) and delta m less than or equal to 0.5.
Weber, Markus; Boehm, Florian; Fischer, Peter; Kraus, Marion; Tashima, Toshiyuki; Liebermeister, Lars; Altpeter, Philipp; Weinfurter, Harald
2016-01-01
We experimentally demonstrate the propagation of long-range surface plasmon-polaritons in a nobel metal stripe waveguide at an optical wavelength of 780 nm. To minimize propagation damping the lithographically structured waveguide is produced from a thin gold stripe embedded in a dielectric polymer. Our waveguide geometry supports a symmetric fundamental and anti-symmetric first order mode. For the fundamental mode we measure a propagation loss of $(6.12^{+0.66} _{-0.54})$ dB/mm, in good agreement with numerical simulations using a vectorial eigenmode solver. Our results are a promising starting point for coupling fluorescence of individual solid state quantum emitters to integrated plasmonic waveguide structures.
Long-range temporal correlations in the EEG bursts of human preterm babies.
Directory of Open Access Journals (Sweden)
Caroline Hartley
Full Text Available The electrical activity in the very early human preterm brain, as recorded by scalp EEG, is mostly discontinuous and has bursts of high-frequency oscillatory activity nested within slow-wave depolarisations of high amplitude. The temporal organisation of the occurrence of these EEG bursts has not been previously investigated. We analysed the distribution of the EEG bursts in 11 very preterm (23-30 weeks gestational age human babies through two estimates of the Hurst exponent. We found long-range temporal correlations (LRTCs in the occurrence of these EEG bursts demonstrating that even in the very immature human brain, when the cerebral cortical structure is far from fully developed, there is non-trivial temporal structuring of electrical activity.
Constraints on flavor-dependent long range forces from solar neutrinos and KamLAND
Bandyopadhyay, A; Joshipura, A S; Bandyopadhyay, Abhijit; Dighe, Amol; Joshipura, Anjan S.
2006-01-01
Flavor-dependent long range (LR) leptonic forces, like those mediated by the $L_e-L_\\mu$ or $L_e -L_\\tau$ gauge bosons, constitute a minimal extension of the standard model that preserves its renormalizability. We study the impact of such interactions on the solar neutrino oscillations when the interaction range $R_{LR}$ is much larger than the Earth-Sun distance. The LR potential can dominate over the standard charged current potential inside the Sun in spite of strong constraints on the coupling $\\alpha$ of the LR force coming from the atmospheric neutrino data and laboratory search for new forces. We demonstrate that the solar and atmospheric neutrino mass scales do not get trivially decoupled even if $\\theta_{13}$ is vanishingly small. In addition, for $\\alpha \\gsim 10^{-52}$ and normal hierarchy, resonant enhancement of $\\theta_{13}$ results in nontrivial energy dependent effects on the $\
Mel'nikov, A S; Buzdin, A I
2016-08-12
The fluctuating superconducting correlations emerging in dirty hybrid structures under the conditions of the strong proximity effect are demonstrated to affect the validity range of the widely used formalism of Usadel equations at mesoscopic scales. In superconductor-ferromagnet structures these giant mesoscopic fluctuations originating from the interference effects for the Cooper pair wave function in the presence of the exchange field can be responsible for an anomalously slow decay of superconducting correlations in a ferromagnet even when the noncollinear and spin-orbit effects are negligible. The resulting sample-to-sample fluctuations of the Josephson current in superconductor-ferromagnetic-superconductor junctions and the local density of states in superconductor-ferromagnetic hybrid structures can provide an explanation of the long-range proximity phenomena observed in mesoscopic samples with collinear magnetization.
PT symmetry breaking in the presence of random, periodic, long-range hopping
Harter, Andrew K.; Onanga, Franck Assogba; Joglekar, Yogesh N.
2016-09-01
Over the past five years, open systems with balanced gain and loss have been investigated for extraordinary properties that are not shared by their closed counterparts. Non-Hermitian, Parity-Time (PT ) symmetric Hamiltonians faithfully model such systems. Such a Hamiltonian typically consists of a reflection-symmetric, Hermitian, nearest-neighbor hopping profile and a PT-symmetric, non-Hermitian, gain and loss potential, and has a robust PT -symmetric phase. Here we investigate the robustness of this phase in the presence of long-range hopping disorder that is not PT-symmetric, but is periodic. We find that the PT-symmetric phase remains robust in the presence of such disorder, and characterize the configurations where that happens. Our results are found using a tight-binding model, and we validate our predictions through the beam-propagation method.
Alberi, K.; Fluegel, B.; Moutinho, H.; Dhere, R. G.; Li, J. V.; Mascarenhas, A.
2013-10-01
Thin-film polycrystalline semiconductors are currently at the forefront of inexpensive large-area solar cell and integrated circuit technologies because of their reduced processing and substrate selection constraints. Understanding the extent to which structural and electronic defects influence carrier transport in these materials is critical to controlling the optoelectronic properties, yet many measurement techniques are only capable of indirectly probing their effects. Here we apply a novel photoluminescence imaging technique to directly observe the low temperature diffusion of photocarriers through and across defect states in polycrystalline CdTe thin films. Our measurements show that an inhomogeneous distribution of localized defect states mediates long-range hole transport across multiple grain boundaries to locations exceeding 10 μm from the point of photogeneration. These results provide new insight into the key role deep trap states have in low temperature carrier transport in polycrystalline CdTe by revealing their propensity to act as networks for hopping conduction.
Babu, K S
2016-01-01
We point out that if the baryon number violating neutron-antineutron oscillation is discovered, it would impose strong limits on the departure from Einstein's equivalence principle at a level of one part in $10^{19}$. If this departure owes its origin to the existence of long-range forces coupled to baryon number $B$ (or $B-L$), it would imply very stringent constraints on the strength of gauge bosons coupling to baryon number current. For instance, if the force mediating baryon number has strength $\\alpha_B$ and its range is larger than a megaparsec, we find the limit to be $\\alpha_B \\leq 2\\times 10^{-57}$, which is much stronger than all other existing bounds. For smaller range for the force, we get slightly weaker, but still stringent bounds by considering the potential of the Earth and the Sun.
Directory of Open Access Journals (Sweden)
Xiaoqiang Sun
2014-01-01
Full Text Available The fabrication and characterization of a thermal variable optical attenuator based on long-range surface plasmon polariton (LRSPP waveguide with multimode interference architecture were investigated. The surface morphology and waveguide configuration of Au stripe were studied by atomic force microscopy. The fluctuation of refractive index of poly(methyl-methacrylate-glycidyl-methacrylate polymer cladding was confirmed to be less than 3×10-4 within 8 h curing at 120°C. The end-fire excitation of LRSPP mode guiding at 1550 nm along Au stripe indicated that the extinction ratio of attenuator was about 12 dB at a driving power of 69 mW. The measured optical rise time and fall time are 0.57 and 0.87 ms, respectively. These favorable properties promise potentials of this plasmonic device in the application of optical interconnection.
Discrete solitons in waveguide arrays with long-range linearly coupled effect
Mai, Zhijie; Wu, Jianxiong; Li, Yongyao
2014-01-01
We study the influences to the discrete soliton (DS) by introducing linearly long-range nonlocal interactions, which give rise to the off-diagonal elements of the linearly coupled matrix in the discrete nonlinear schrodinger equation to be filled by non-zero terms. Theoretical analysis and numerical simulations find that the DS under this circumstance can exhibit strong digital effects: the fundamental DS is a narrow one, which occupies nearly only one waveguide, the dipole and double-monopole solitons, which occupy two waveguides, can be found in self-focusing and -defocusing nonlinearities, respectively. Stable flat-top solitons and their stagger counterparts, which occupy a controllable number of waveguides, can also be obtained through this system. Such digital properties may give rise to additional data processing applications and have potential in fabricating digital optical devices in all-optical networks.
Protein adsorption on tailored substrates: long-range forces and conformational changes
Bellion, M.; Santen, L.; Mantz, H.; Hähl, H.; Quinn, A.; Nagel, A.; Gilow, C.; Weitenberg, C.; Schmitt, Y.; Jacobs, K.
2008-10-01
Adsorption of proteins onto solid surfaces is an everyday phenomenon that is not yet fully understood. To further the current understanding, we have performed in situ ellipsometry studies to reveal the adsorption kinetics of three different proteins, lysozyme, α-amylase and bovine serum albumin. As substrates we offer Si wafers with a controlled Si oxide layer thickness and a hydrophilic or hydrophobic surface functionalization, allowing the tailoring of the influence of short- and long-range interactions. Our studies show that not only the surface chemistry determines the properties of an adsorbed protein layer but also the van der Waals contributions of a composite substrate. We compare the experimental findings to results of a colloidal Monte Carlo approach that includes conformational changes of the adsorbed proteins induced by density fluctuations.
Effect of Synaptic Connectivity on Long-Range Synchronization of Fast Cortical Oscillations
Bazhenov, M.; Rulkov, N. F.; Timofeev, I.
2008-01-01
Cortical gamma oscillations in the 20- to 80-Hz range are associated with attentiveness and sensory perception and have strong connections to both cognitive processing and temporal binding of sensory stimuli. These gamma oscillations become synchronized within a few milliseconds over distances spanning a few millimeters in spite of synaptic delays. In this study using in vivo recordings and large-scale cortical network models, we reveal a critical role played by the network geometry in achieving precise long-range synchronization in the gamma frequency band. Our results indicate that the presence of many independent synaptic pathways in a two-dimensional network facilitate precise phase synchronization of fast gamma band oscillations with nearly zero phase delays between remote network sites. These findings predict a common mechanism of precise oscillatory synchronization in neuronal networks. PMID:18632897
Ultra-long-range giant dipole molecules in crossed electric and magnetic fields
Kurz, Markus; Schmelcher, Peter
2011-01-01
We show the existence of ultra-long-range giant dipole molecules formed by a neutral alkali ground state atom that is bound to the decentered electronic wave function of a giant dipole atom. The adiabatic potential surfaces emerging from the interaction of the ground state atom with the giant dipole electron posses a rich topology depending on the degree of electronic excitation. Binding energies and the vibrational motion in the energetically lowest surfaces are analyzed by means of perturbation theory and exact diagonalization techniques. The resulting molecules are truly giant with internuclear distances up to several $\\mu m$. Finally, we demonstrate the existence of intersection manifolds of excited electronic states that potentially lead to a vibrational decay of the ground state atom dynamics.
On the long-range correlations in hadron-nucleus collisions
Armesto, N; Pajares, C
2007-01-01
Long-range correlations between multiplicities in different rapidity windows in hadron-nucleus collisions are analyzed. After recalling the standard results in the probabilistic model, we study them in the framework of perturbative QCD. Considering interacting BFKL pomerons in the form of fan diagrams coupled to a dilute projectile, analytic estimates are done for very large rapidities. The correlation strength results weakly depending on energy and centrality or nuclear size, and generically greater than unity. Finally, we turn to the Color Glass Condensate framework. For a saturated projectile, the resulting correlation strength turns out to be smaller than unity and decreasing with increasing energy. Its behavior with increasing centrality or nuclear size depends on the considered rapidity windows.
Long-range autocorrelations of CpG islands in the human genome.
Directory of Open Access Journals (Sweden)
Benjamin Koester
Full Text Available In this paper, we use a statistical estimator developed in astrophysics to study the distribution and organization of features of the human genome. Using the human reference sequence we quantify the global distribution of CpG islands (CGI in each chromosome and demonstrate that the organization of the CGI across a chromosome is non-random, exhibits surprisingly long range correlations (10 Mb and varies significantly among chromosomes. These correlations of CGI summarize functional properties of the genome that are not captured when considering variation in any particular separate (and local feature. The demonstration of the proposed methods to quantify the organization of CGI in the human genome forms the basis of future studies. The most illuminating of these will assess the potential impact on phenotypic variation of inter-individual variation in the organization of the functional features of the genome within and among chromosomes, and among individuals for particular chromosomes.
Constraints on the possible long-range orbital ordering in LaCoO3
Phelan, D.
2014-01-01
A neutron powder diffraction measurement was performed to distinguish between the proposed monoclinic (I2/a) structure of LaCoO3, which is consistent with orbital ordering, and the rhombohedral (R3¯c) structure, which is inconsistent with orbital ordering. These two structures were differentiated through a measurement of a superlattice reflection with a d-spacing of approximately 4.43 Å which is only generated by I2/a. This reflection was not observed, and instead a restrictive upper bound was placed on its structure factor. The data is inconsistent with the monoclinic structure and suggests that there may be no long-range Jahn-Teller distortion in LaCoO3.
High-power laser delocalization in plasmas leading to long-range beam merging
Energy Technology Data Exchange (ETDEWEB)
Nakatsutsumi, M.; Marques, J.R.; Antici, P.; Bourgeois, N.; Romagnani, L.; Audebert, P.; Fuchs, J. [UPMC, CEA, CNRS, LULI, Ecole Polytech, F-91128 Palaiseau (France); Nakatsutsumi, M.; Kodama, R. [Osaka Univ, Grad Sch Engn, Suita, Osaka 5650871 (Japan); Antici, P. [Univ Roma La Sapienza, Dipartimento SBAI, I-00161 Rome (Italy); Feugeas, J.L.; Nicolai, P. [Univ Bordeaux 1, CNRS, CEA, Ctr Lasers Intenses and Applicat, F-33405 Talence (France); Lin, T. [Fox Chase Canc Ctr, Philadelphia, PA 19111 (United States)
2010-07-01
Attraction and fusion between co-propagating light beams, mutually coherent or not, can take place in nonlinear media as a result of the beam power modifying the refractive index of the medium. In the context of high-power light beams, induced modifications of the beam patterns could potentially impact many topics, including long-range laser propagation, the study of astrophysical colliding blast waves and inertial confinement fusion. Here, through experiments and simulations, we show that in a fully ionized plasma, which is a nonlinear medium, beam merging can take place for high-power and mutually incoherent beams that are initially separated by several beam diameters. This is in contrast to the usual assumption that this type of interaction is limited to beams separated by only one beam diameter. This effect, which is orders of magnitude more significant than Kerr-like nonlinearity in gases, demonstrates the importance of potential cross-talk amongst multiple beams in plasma. (authors)
Hyperfine-frequency shifts of alkali-metal atoms during long-range collisions
McGuyer, B H
2013-01-01
Collisions with chemically inert atoms or molecules change the hyperfine coupling of an alkali-metal atom through the hyperfine-shift interaction. This interaction is responsible for the pressure shifts of the microwave resonances of alkali-metal atoms in buffer gases, is an important spin interaction in alkali-metal--noble-gas van der Waals molecules, and is anticipated to enable the magnetoassociation of ultracold molecules such as RbSr. An improved estimate is presented for the long-range asymptote of this interaction for Na, K, Rb, and Cs. To test the results, the change in hyperfine coupling due to a static electric field is estimated and reasonable agreement is found.
Long-range wireless mesh network for weather monitoring in unfriendly geographic conditions.
Toledano-Ayala, Manuel; Herrera-Ruiz, Gilberto; Soto-Zarazúa, Genaro M; Rivas-Araiza, Edgar A; Bazán Trujillo, Rey D; Porrás-Trejo, Rafael E
2011-01-01
In this paper a long-range wireless mesh network system is presented. It consists of three main parts: Remote Terminal Units (RTUs), Base Terminal Units (BTUs) and a Central Server (CS). The RTUs share a wireless network transmitting in the industrial, scientific and medical applications ISM band, which reaches up to 64 Km in a single point-to-point communication. A BTU controls the traffic within the network and has as its main task interconnecting it to a Ku-band satellite link using an embedded microcontroller-based gateway. Collected data is stored in a CS and presented to the final user in a numerical and a graphical form in a web portal.
Effective-medium approximation for lattice random walks with long-range jumps
Thiel, Felix; Sokolov, Igor M.
2016-07-01
We consider the random walk on a lattice with random transition rates and arbitrarily long-range jumps. We employ Bruggeman's effective-medium approximation (EMA) to find the disorder-averaged (coarse-grained) dynamics. The EMA procedure replaces the disordered system with a cleverly guessed reference system in a self-consistent manner. We give necessary conditions on the reference system and discuss possible physical mechanisms of anomalous diffusion. In the case of a power-law scaling between transition rates and distance, lattice variants of Lévy-flights emerge as the effective medium, and the problem is solved analytically, bearing the effective anomalous diffusivity. Finally, we discuss several example distributions and demonstrate very good agreement with numerical simulations.
CGC/saturation approach for soft interactions at high energy: long range rapidity correlations
Energy Technology Data Exchange (ETDEWEB)
Gotsman, E.; Maor, U. [Tel Aviv University, Department of Particle Physics, School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Science, Tel Aviv (Israel); Levin, E. [Tel Aviv University, Department of Particle Physics, School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Science, Tel Aviv (Israel); Universidad Tecnica Federico Santa Maria and Centro Cientifico- Tecnologico de Valparaiso, Departemento de Fisica, Valparaiso (Chile)
2015-11-15
In this paper we continue our program to construct a model for high energy soft interactions that is based on the CGC/saturation approach. The main result of this paper is that we have discovered a mechanism that leads to large long range rapidity correlations and results in large values of the correlation function R(y{sub 1}, y{sub 2}) ≥ 1, which is independent of y{sub 1} and y{sub 2}. Such a behavior of the correlation function provides strong support for the idea that at high energies the system of partons that is produced is not only dense but also has strong attractive forces acting between the partons. (orig.)
Shot-gun sequencing strategy for long-range genome mapping: a pilot study.
Zabarovsky, E R; Kashuba, V I; Pettersson, B; Petrov, N; Zakharyev, V; Gizatullin, R; Lebedeva, T; Bannikov, V; Pokrovskaya, E S; Zabarovska, V I
1994-06-01
We have recently proposed a strategy for construction of long-range physical maps based on random sequencing of NotI linking and jumping clones. Here, we present results of sequence comparison between 168 NotI linking (100 of them were sequenced from both sides) and 81 chromosome 3-specific jumping clones. We were able to identify 14 NotI jumping clones (17%), each joined with two NotI linking clones. The average size of chromosomal jumps was about 650 kb. The assembled 42 NotI genomic fragments correspond to 12-15% of chromosome 3. These results demonstrate the value of random sequencing of NotI linking and jumping clones for genome mapping. This mapping proposal can be used for connecting physical and genetic maps of the human genome and will be a valuable supplement to YAC and cosmid library based mapping projects.
Oak Ridge National Laboratory Health and Safety Long-Range Plan: Fiscal years 1989--1995
Energy Technology Data Exchange (ETDEWEB)
1989-06-01
The health and safety of its personnel is the first concern of ORNL and its management. The ORNL Health and Safety Program has the responsibility for ensuring the health and safety of all individuals assigned to ORNL activities. This document outlines the principal aspects of the ORNL Health and Safety Long-Range Plan and provides a framework for management use in the future development of the health and safety program. Each section of this document is dedicated to one of the health and safety functions (i.e., health physics, industrial hygiene, occupational medicine, industrial safety, nuclear criticality safety, nuclear facility safety, transportation safety, fire protection, and emergency preparedness). Each section includes functional mission and objectives, program requirements and status, a summary of program needs, and program data and funding summary. Highlights of FY 1988 are included.
Universal threshold for the dynamical behavior of lattice systems with long-range interactions.
Bachelard, Romain; Kastner, Michael
2013-04-26
Dynamical properties of lattice systems with long-range pair interactions, decaying like 1/r(α) with the distance r, are investigated, in particular the time scales governing the relaxation to equilibrium. Upon varying the interaction range α, we find evidence for the existence of a threshold at α=d/2, dependent on the spatial dimension d, at which the relaxation behavior changes qualitatively and the corresponding scaling exponents switch to a different regime. Based on analytical as well as numerical observations in systems of vastly differing nature, ranging from quantum to classical, from ferromagnetic to antiferromagnetic, and including a variety of lattice structures, we conjecture this threshold and some of its characteristic properties to be universal.
From phase separation to long-range order in a system of interacting electrons
Derzhko, Volodymyr; Jȩdrzejewski, Janusz
2003-10-01
We study a system composed of fermions (electrons), hopping on a square lattice, and of immobile particles (ions), that is described by the spinless Falicov-Kimball Hamiltonian augmented by a next-nearest-neighbor attractive interaction between the ions (a nearest-neighbor repulsive interaction between the ions can be included and does not alter the results). A part of the grand-canonical phase diagram of this system is constructed rigorously, when the coupling between the electrons and ions is much stronger than the hopping intensity of electrons. The obtained diagram implies that, at least for a few rational densities of particles, by increasing the hopping intensity the system can be driven from a state of phase separation to a state with a long-range order. This kind of transitions occurs also, when the hopping fermions are replaced by hopping hard-core bosons.
A Study of LoRa: Long Range & Low Power Networks for the Internet of Things
Augustin, Aloÿs; Yi, Jiazi; Clausen, Thomas; Townsley, William Mark
2016-01-01
LoRa is a long-range, low-power, low-bitrate, wireless telecommunications system, promoted as an infrastructure solution for the Internet of Things: end-devices use LoRa across a single wireless hop to communicate to gateway(s), connected to the Internet and which act as transparent bridges and relay messages between these end-devices and a central network server. This paper provides an overview of LoRa and an in-depth analysis of its functional components. The physical and data link layer performance is evaluated by field tests and simulations. Based on the analysis and evaluations, some possible solutions for performance enhancements are proposed. PMID:27618064
A note on the eigenvectors of long-range spin chains and their scalar products
Serban, Didina
2012-01-01
In this note, we propose an expression for the eigenvectors and scalar products for a class of spin chains with long-range interaction and su(2) symmetry. This class includes the Inozemtsev spin chain as well as the BDS spin chain, which is a reduction of the one-dimensional Hubbard model at half-filling to the spin sector. The proposal is valid for large spin chains and is based on the construction of the monodromy matrix using the Dunkl operators. For the Inozemtsev model these operators are known explicitly. This construction gives in particular the eigenvectors of the dilatation operator of the N=4 gauge theory in the su(2) sector up to three-loop order, as well as their scalar products. We suggest how this will affect the expression for the three-point functions obtained by I. Kostov and how to include the all-loop interaction.
Integrated optical gyroscope using active long-range surface plasmon-polariton waveguide resonator.
Zhang, Tong; Qian, Guang; Wang, Yang-Yang; Xue, Xiao-Jun; Shan, Feng; Li, Ruo-Zhou; Wu, Jing-Yuan; Zhang, Xiao-Yang
2014-01-24
Optical gyroscopes with high sensitivity are important rotation sensors for inertial navigation systems. Here, we present the concept of integrated resonant optical gyroscope constructed by active long-range surface plasmon-polariton (LRSPP) waveguide resonator. In this gyroscope, LRSPP waveguide doped gain medium is pumped to compensate the propagation loss, which has lower pump noise than that of conventional optical waveguide. Peculiar properties of single-polarization of LRSPP waveguide have been found to significantly reduce the polarization error. The metal layer of LRSPP waveguide is electro-optical multiplexed for suppression of reciprocal noises. It shows a limited sensitivity of ~10(-4) deg/h, and a maximum zero drift which is 4 orders of magnitude lower than that constructed by conventional single-mode waveguide.
Quasi-long-range ordering in a finite-size 2D Heisenberg model
Kapikranian, O; Holovatch, Yu; Berche, Bertrand; Holovatch, Yurij; Kapikranian, Oleksandr
2006-01-01
We analyse the low-temperature behaviour of the Heisenberg model on a two-dimensional lattice of finite size. Presence of a residual magnetisation in a finite-size system enables us to use the spin wave approximation, which is known to give reliable results for the XY model at low temperatures T. For the system considered, we find that the spin-spin correlation function decays as 1/r^eta(T) for large separations r bringing about presence of a quasi-long-range ordering. We give analytic estimates for the exponent eta(T) in different regimes and support our findings by Monte Carlo simulations of the model on lattices of different sizes at different temperatures.
Reexamination of the long-range Potts model: a multicanonical approach.
Reynal, S; Diep, H T
2004-02-01
We investigate the critical behavior of the one-dimensional q-state Potts model with long-range (LR) interactions 1/r(d+sigma), using a multicanonical algorithm. The recursion scheme initially proposed by Berg is improved so as to make it suitable for a large class of LR models with unequally spaced energy levels. The choice of an efficient predictor and a reliable convergence criterion is discussed. We obtain transition temperatures in the first-order regime which are in far better agreement with mean-field predictions than in previous Monte Carlo studies. By relying on the location of spinodal points and resorting to scaling arguments, we determine the threshold value sigma(c)(q) separating the first- and second-order regimes to two-digit precision within the range 3sigma(c)(q)sigma<1.2, thus lending strong support to Sak's scenario.
Dependence of simulations of long range transport on meteorology, model and dust size
Mahowald, N. M.; Albani, S.; Smith, M.; Losno, R.; Marticorena, B.; Ridley, D. A.; Heald, C. L.; Qu, Z.
2015-12-01
Mineral aerosols interact with radiation directly, as well as modifying climate, and provide important micronutrients to ocean and land ecosystems. Mineral aerosols are transported long distances from the source regions to remote regions, but the rates at which this occurs can be difficult to deduce from either observations or models. Here we consider interactions between the details of the simulation of dust size and long-range transport. In addition, we compare simulations of dust using multiple reanalysis datasets, as well as different model basis to understand how robust the mean, seasonality and interannual variability are in models. Models can provide insight into how long observations are required in order to characterize the atmospheric concentration and deposition to remote regions.
Long-range magnetic ordering in magnetic ionic liquid: Emim[FeCl{sub 4}
Energy Technology Data Exchange (ETDEWEB)
De Pedro, I; Rojas, D P; Rodriguez Fernandez, J [CITIMAC, Facultad de Ciencias, Universidad de Cantabria, 39005 Santander (Spain); Albo, J; Luis, P; Irabien, A [Departamento de Ingenierioa Quimica y Quimica Inorganica, Universidad de Cantabria, 39005 Santander (Spain); Blanco, Jesus A, E-mail: rodrigufj@unican.e [Departamento de Fisica, Universidad de Oviedo, 33007 Oviedo (Spain)
2010-07-28
Up to now most of the magnetic ionic liquids containing tetrachloroferrate ion FeCl{sub 4} have evidenced a paramagnetic temperature dependence of the magnetic susceptibility, with only small deviations from the Curie law at low temperatures. However, we report on the physical properties of 1-ethyl-3-methylimidazolium tetrachloroferrate Emim[FeCl{sub 4}], that clearly shows a long-range antiferromagnetic ordering below the Neel temperature T{sub N{approx}}3.8 K. In addition, the field dependence of the magnetization measured at 2 K is characterized by a linear behaviour up to around 40 kOe, while above this field the magnetization becomes saturated with a value of 4.3 {mu}{sub B}/Fe, which is near the expected fully saturated value of 5 {mu}{sub B}/Fe for an Fe{sup 3+} ion.
Propagation of long-range surface plasmon polaritons in photonic crystals
DEFF Research Database (Denmark)
Boltasseva, Alexandra; Søndergaard, Thomas; Nikolajsen, T.
2005-01-01
We study the interaction of long-range surface plasmon polaritons (LR-SPPs), excited at telecommunication wavelengths, with photonic crystals (PCs) formed by periodic arrays of gold bumps that are arranged in a triangular lattice and placed symmetrically on both sides of a thin gold film embedded...... in polymer. Radiation is delivered to and from the PC structures with the help of LR-SPP guides that consist of 8 mu m wide and 15 nm thick gold stripes attached to wide film sections (of the same thickness) covered with bumps (diameter similar to 300 nm, height up to 150 nm on each side of the film). We......) into the investigated PC structures. Using a self-consistent description based on the Green'S function formalism, we simulate numerically the LR-SPP transmission through and reflection from finite-size PC structures consisting of finite-size scatterers, as well as the LR-SPP guiding along line defects...
Propagation of long-range surface plasmon polaritons in photonic band gap structures
DEFF Research Database (Denmark)
Boltasseva, Alexandra; Søndergaard, Thomas; Nikolajsen, Thomas
2005-01-01
We study the interaction of long-range surface plasmon polaritons (LR-SPPs), excited at telecommunication wavelengths, with photonic crystals (PCs) formed by periodic arrays of gold bumps that are arranged in a triangular lattice and placed symmetrically on both sides of a thin gold fil embedded...... in polymer. Radiation is delivered to and from the PC structures with the help of LR-SPP guides that consist of 8 mm wide and 15 nm thick gold stripes attached to wide film sections (of the same thickness) covered with bumps (diameter ~300 nm, height up to 150 nm on each side of the film). We investigate...... structures. Using a self-consistent description based on the Green's function formalism, we simulate numerically the LR-SPP transmission through and reflection from finite-size PC structures consisting of finite-size scatterers, as well as the LR-SPP guiding along line defects in these structures...
Long-Range Geo-Monitoring Using Image Assisted Total Stations
Wagner, Andreas; Huber, Ben; Wiedemann, Wolfgang; Paar, Gerhard
2014-09-01
Image Assisted Total Stations (IATS) unify geodetic precision of total stations with areal coverage of images. The concept of using two IATS devices for high-resolution, long-range stereo survey of georisk areas has been investigated in the EU-FP7 project DE-MONTES (www.de-montes.eu). The paper presents the used methodology and compares the main features with other terrestrial geodetic geo-monitoring methods. The theoretically achievable accuracy of the measurement systemis derived and verified by ground truth data of a distant clay pit slope and simulated deformations. It is shown that the stereo IATS concept is able to obtain higher precision in the determination of 3D deformations than other systems of comparable sensor establishment effort.
Long-range correlation in synchronization and syncopation tapping: a linear phase correction model.
Directory of Open Access Journals (Sweden)
Didier Delignières
Full Text Available We propose in this paper a model for accounting for the increase in long-range correlations observed in asynchrony series in syncopation tapping, as compared with synchronization tapping. Our model is an extension of the linear phase correction model for synchronization tapping. We suppose that the timekeeper represents a fractal source in the system, and that a process of estimation of the half-period of the metronome, obeying a random-walk dynamics, combines with the linear phase correction process. Comparing experimental and simulated series, we show that our model allows accounting for the experimentally observed pattern of serial dependence. This model complete previous modeling solutions proposed for self-paced and synchronization tapping, for a unifying framework of event-based timing.
A Study of LoRa: Long Range & Low Power Networks for the Internet of Things.
Augustin, Aloÿs; Yi, Jiazi; Clausen, Thomas; Townsley, William Mark
2016-09-09
LoRa is a long-range, low-power, low-bitrate, wireless telecommunications system, promoted as an infrastructure solution for the Internet of Things: end-devices use LoRa across a single wireless hop to communicate to gateway(s), connected to the Internet and which act as transparent bridges and relay messages between these end-devices and a central network server. This paper provides an overview of LoRa and an in-depth analysis of its functional components. The physical and data link layer performance is evaluated by field tests and simulations. Based on the analysis and evaluations, some possible solutions for performance enhancements are proposed.
Two-dimensional-lattice spin models with long-range antiferromagnetic interactions
Romano, S.
1991-10-01
We consider a classical system, consisting of m-component unit vectors (m=2,3), associated with a two-dimensional lattice \\{uk||k∈openZ2\\} and interacting via translationally and rotationally invariant antiferromagnetic pair potentials of the long-range form W=Wjk=ɛ||xj-xk||-puj.uk, p>2, where ɛ is a positive quantity, setting energy and temperature scales (i.e., T*=kBT/ɛ), and xk are the coordinates of the lattice sites. A spin-wave approach predicts orientational disorder (in the thermodynamic limit) at all finite temperatures and for all p>2 this agrees with available rigorous results for p>=4, whereas no such theorems are known in the literature when 22.
Long-range magnetic order in models for rare-earth quasicrystals
Thiem, Stefanie; Chalker, J. T.
2015-12-01
We take a two-step theoretical approach to study magnetism of rare-earth quasicrystals by considering Ising spins on quasiperiodic tilings, coupled via Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions. First, we compute RKKY interactions from a tight-binding Hamiltonian defined on the two-dimensional quasiperiodic tilings. We find that the magnetic interactions are frustrated and strongly dependent on the local environment. This results in the formation of clusters with strong bonds at certain patterns of the tilings that repeat quasiperiodically. Second, we examine the statistical mechanics of Ising spins with these RKKY interactions, using extensive Monte Carlo simulations. Although models that have frustrated interactions and lack translational invariance might be expected to display spin-glass behavior, we show that the spin system has a phase transition to low-temperature states with long-range quasiperiodic magnetic order. Additionally, we find that in some of the systems spin clusters can fluctuate much below the ordering temperature.
Even-Odd Effects of Heisenberg Chains on Long-range Interaction and Entanglement
Oh, Sangchul; Hu, Xuedong
2010-01-01
A strongly coupled Heisenberg chain provides an important channel for quantum communication through its many-body ground state. Yet, the nature of the effective interactions and the ability to mediate long-range entanglement differs significantly for chains of opposite parity. Here, we contrast the characters of even and odd-size chains when they are coupled to external qubits. Additional parity effects emerge in both cases, depending on the positions of the attached qubits. Some striking results include (i) the emergence of maximal entanglement and (ii) Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions for qubits attached to an even chain, and (iii) the ability of chains of either parity to mediate qubit entanglement that is undiminished by distance.
Brandenburg, J G; Ruzsinszky, A; Sun, J; Perdew, J P
2016-01-01
The strongly constrained and appropriately normed (SCAN) semilocal density functional [J. Sun, A. Ruzsinszky, J. P. Perdew \\textit{Phys. Rev. Lett.} {\\bf 115}, 036402 (2015)] obeys all 17 known exact constraints for meta-generalized-gradient approximations (meta-GGA) and includes some medium range correlation effects. Long-range London dispersion interactions are still missing, but can be accounted for via an appropriate correction scheme. In this study, we combine SCAN with an efficient London dispersion correction and show that lattice energies of simple organic crystals can be improved with the applied correction by 50\\%. The London-dispersion corrected SCAN meta-GGA outperforms all other tested London-dispersion corrected meta-GGAs for molecular geometries. Our new method delivers mean absolute deviations (MADs) for main group bond lengths that are consistently below 1\\,pm, rotational constants with MADs of 0.2\\%, and noncovalent distances with MADs below 1\\%. For a large database of general main group th...
Elastic Curves and Surfaces Under Long-Range Forces: a Geometric Approach
Santiago, J. A.; Chacón-Acosta, G.; González-Gaxiola, O.
2013-05-01
Using classical differential geometry, the problem of elastic curves and surfaces in the presence of long-range interactions Φ, is posed. Starting from a variational principle, the balance of elastic forces and the corresponding projections niṡ∇Φ, are found. In the case of elastic surfaces, a force coupling the mean curvature with the external potential, KΦ, appears; it is also present in the shape equation along the normal principal in the case of curves. The potential Φ contributes to the effective tension of curves and surfaces and also to the orbital torque. The confinement of a curve on a surface is also addressed, in such a case, the potential contributes to the normal force through the terms -κΦ-nṡ∇Φ. In general, the equation of motion becomes integro-differential that must be numerically solved.
Magnetic fields in long-range alignment of functional hybrid soft materials
Majewski, Pawel; Gopinadhan, Manesh; Pelligra, Candice; Zhang, Shanju; Pfefferle, Lisa; Osuji, Chinedum
2012-02-01
We present a magnetic field-based method to impose long range order in self-assembled soft materials including polymer-nanowire composites, block copolymers and surfactant mesophases. We discuss the broad utility of this approach, indicating its advantages and limitations. Our method yields highly anisotropic materials with quality of alignment in many cases comparable to that of single crystals as assessed by X-ray scattering techniques. We take advantage of the high fidelity of alignment to systematically explore and characterize the anisotropic properties of these materials. We present a perspective for improving electron and hole transport, as well as exciton utilization in magnetically doped ZnO nanowire-polythiophene composites for photovoltaic applications by global alignment of the nanowires. For block copolymers, we focus on enhancing Li-ion transport in membranes with self-assembled cylindrical and lamellar morphology by alignment of the Li-conducting PEO domains.
Microemulsion phases in one and two dimensional magnetic models with long-range interactions
Nielsen, Erik; Bhatt, R. N.; Huse, David
2007-03-01
Spivak and Kivelson have proposed that the first order phase transition between the Wigner crystal and Fermi liquid phases of the interacting electron gas in two dimensions is pre-empted by a series of microemulsion phases characterized by phase separation on the mesoscopic scale, which may be responsible for the anomalous conductivity. We have studied analogous classical magnetic models in one and two dimensions. In particular, we present an exact analytical solution of a one dimensional classical ferromagnetic Ising spin chain frustrated by a long range antiferromagnetic interaction, which clearly exhibits such phase separation in which the mesoscale varies continuously with applied magnetic field. We describe these phases in the 1D model and consider extensions to stripe and bubble phases in two dimensions. B. Spivak and S. A.Kivelson, Physical Review B, 70 155114 (2004) K. Ng and D. Vanderbilt, Physical Review B, 52 2177 (1995)
Long-range angular correlation in dissipative reaction of 27Al+27A1
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
Angular correlation of excitation functions in dissipative heavy ion collision 27Al+27A1 has been measured. The incident beam energies ranged from 114MeV to 127 MeV in steps of 200keV. The angular analysis region was continuous from 50° to 90° in the center of mass system. An angular coherent width, at least 40°, was obtained. This long-range angular correlation could not be interpreted in the framework of the standard statistical reaction theory with state of equilibrium or near equilibrium, maybe it reveals the formation of a new kind ofdissipative structure in the reaction of 27Al+27A1 with the state that is far from equilibrium.
Long-range surface plasmon polariton nanowire waveguides for device applications
DEFF Research Database (Denmark)
Leosson, Kristjan; Nikolajsen, T.; Boltasseva, Alexandra;
2006-01-01
We report an experimental study of long-range surface plasmon polaritons propagating along metallic wires of sub-micrometer rectangular cross-sections (nanowires) embedded in a dielectric. At telecom wavelengths, optical signals are shown to propagate up to several millimeters along such nanowires....... As the wires approach a square cross-section, the guided mode becomes more symmetric and can, for example, be tuned to match closely the mode of a standard single-mode optical fiber. Furthermore, symmetric nanowires are shown to guide both TM and TE polarizations. In order to illustrate the applicability...... of plasmonic nanowire waveguides to optical circuits, we demonstrate a compact variable optical attenuator consisting of a single nanowire that simultaneously carries light and electrical current....
Alberi, K; Fluegel, B; Moutinho, H; Dhere, R G; Li, J V; Mascarenhas, A
2013-01-01
Thin-film polycrystalline semiconductors are currently at the forefront of inexpensive large-area solar cell and integrated circuit technologies because of their reduced processing and substrate selection constraints. Understanding the extent to which structural and electronic defects influence carrier transport in these materials is critical to controlling the optoelectronic properties, yet many measurement techniques are only capable of indirectly probing their effects. Here we apply a novel photoluminescence imaging technique to directly observe the low temperature diffusion of photocarriers through and across defect states in polycrystalline CdTe thin films. Our measurements show that an inhomogeneous distribution of localized defect states mediates long-range hole transport across multiple grain boundaries to locations exceeding 10 μm from the point of photogeneration. These results provide new insight into the key role deep trap states have in low temperature carrier transport in polycrystalline CdTe by revealing their propensity to act as networks for hopping conduction.
Long-Range Alpha Detector (LRAD) technology applied to ER and D&D problems
Energy Technology Data Exchange (ETDEWEB)
Allander, K.S.; Bounds, J.A.; Caress, R.W.; Catlett, M.M.; Garner, S.E.; Johnson, J.P.; Johnson, J.D.; MacArthur, D.W.; Rutherford, D.A.
1993-11-01
Standard alpha detectors are severely limited when monitoring alpha contamination on large surfaces and the inside surfaces of pipes, ducts, and equipment. The Long-Range Alpha Detector (LRAD) system overcomes these problems by detecting the ion pairs created by an alpha particle in ambient air, rather than the alpha particle directly. These ion pairs are transported to a collection grid by either an air current or an electric field and create a small electric current (typically 10{sup {minus}13} to 10{sup {minus}14} A) that is read by an electrometer and displayed on a data acquisition system. This method of detection is used to create monitoring systems for both the environmental restoration and decontamination and decommissioning fields.
Robust unidirectional transport in a one-dimensional metacrystal with long-range hopping
Longhi, Stefano
2016-01-01
In two- and three-dimensional structures, topologically-protected chiral edge modes offer a powerful mean to realize robust light transport. However, little attention has been paid so far to robust one-way transport in one-dimensional systems. Here it is shown that unidirectional transport, which is immune to disorder and backscattering, can occur in certain one-dimensional metacrystals with long-range hopping without resorting to topological protection. Such metacrystals are described by an effective Hermitian Hamiltonian with broken time reversal symmetry, and transport does not require adiabatic (Thouless) pumping. A simple implementation in optics of such one-dimensional metacrystals, based on transverse light dynamics in a self-imaging optical cavity with phase gratings, is suggested
Infinite matrix product states for long-range SU(N) spin models
Energy Technology Data Exchange (ETDEWEB)
Bondesan, Roberto, E-mail: Roberto.Bondesan@uni-koeln.de; Quella, Thomas, E-mail: Thomas.Quella@uni-koeln.de
2014-09-15
We construct 1D and 2D long-range SU(N) spin models as parent Hamiltonians associated with infinite matrix product states. The latter are constructed from correlators of primary fields in the SU(N){sub 1} WZW model. Since the resulting groundstates are of Gutzwiller–Jastrow type, our models can be regarded as lattice discretizations of fractional quantum Hall systems. We then focus on two specific types of 1D spin chains with spins located on the unit circle, a uniform and an alternating arrangement. For an equidistant distribution of identical spins we establish an explicit connection to the SU(N) Haldane–Shastry model, thereby proving that the model is critical and described by a SU(N){sub 1} WZW model. In contrast, while turning out to be critical as well, the alternating model can only be treated numerically. Our numerical results rely on a reformulation of the original problem in terms of loop models.
Tailored long range forces on polarizable particles by collective scattering of broadband radiation
Holzmann, Daniela
2016-01-01
Collective coherent light scattering by polarizable particles creates surprisingly strong, long range inter-particle forces originating from interference of the light scattered by different particles. While for monochromatic laser beams this interaction decays with the inverse distance, we show here that in general the effective interaction range and geometry can be controlled by the illumination bandwidth and geometry. As generic example we study the modifications inter-particle forces within a 1D chain of atoms trapped in the field of a confined optical nanofiber mode. For two particles we find short range attraction as well as optical binding at multiple distances. The range of stable distances shrinks with increasing light bandwidth and for a very large bandwidth field as e.g. blackbody radiation we find a strongly attractive potential up to a critical distance beyond which the force gets repulsive. Including multiple scattering can even lead to the appearance of a stable configuration at a large distance...
Alves, L G A; Guimarães, R R; Nakamura, C V; Mendes, R S; Ribeiro, H V
2016-01-01
We report on a diffusive analysis of the motion of flagellate protozoa species. These parasites are the etiological agents of neglected tropical diseases: leishmaniasis caused by \\textit{Leishmania amazonensis} and \\textit{Leishmania braziliensis}, African sleeping sickness caused by \\textit{Trypanosoma brucei}, and Chagas disease caused by \\textit{Trypanosoma cruzi}. By tracking the positions of these parasites and evaluating the variance related to the radial positions, we find that their motions are characterized by a short-time transient superdiffusive behavior. Also, the probability distributions of the radial positions are self-similar and can be approximated by a stretched Gaussian distribution. We further investigate the probability distributions of the radial velocities of individual trajectories. Among several candidates, we find that the generalized gamma distribution shows a good agreement with these distributions. The velocity time series have long-range correlations, displaying a strong persiste...
Long-Range Atom--Wall Interactions and Mixing Terms: Metastable Hydrogen
Jentschura, U D
2015-01-01
We investigate the interaction of metastable 2S hydrogen atoms with a perfectly conducting wall, including parity-breaking S-P mixing terms (with full account of retardation). The neighboring 2P_1/2 and 2P_3/2 levels are found to have a profound effect on the transition from the short-range, nonrelativistic regime, to the retarded form of the Casimir-Polder interaction. The corresponding P state admixtures to the metastable 2S state are calculated. We find the long-range asymptotics of the retarded Casimir-Polder potentials and mixing amplitudes, for general excited states, including a fully quantum electrodynamic treatment of the dipole-quadrupole mixing term. The decay width of the metastable 2S state is roughly doubled even at a comparatively large distance of 918 atomic units (Bohr radii) from the perfect conductor. The magnitude of the calculated effects is compared to the unexplained Sokolov effect.
Effective-medium approximation for lattice random walks with long-range jumps.
Thiel, Felix; Sokolov, Igor M
2016-07-01
We consider the random walk on a lattice with random transition rates and arbitrarily long-range jumps. We employ Bruggeman's effective-medium approximation (EMA) to find the disorder-averaged (coarse-grained) dynamics. The EMA procedure replaces the disordered system with a cleverly guessed reference system in a self-consistent manner. We give necessary conditions on the reference system and discuss possible physical mechanisms of anomalous diffusion. In the case of a power-law scaling between transition rates and distance, lattice variants of Lévy-flights emerge as the effective medium, and the problem is solved analytically, bearing the effective anomalous diffusivity. Finally, we discuss several example distributions and demonstrate very good agreement with numerical simulations.
Long-range Acoustic Interactions in Insect Swarms: An Adaptive Gravity Model
Gorbonos, Dan; Puckett, James G; Ni, Rui; Ouellette, Nicholas T; Gov, Nir S
2015-01-01
The collective motion of groups of animals emerges from the net effect of the interactions between individual members of the group. In many cases, such as birds, fish, or ungulates, these interactions are mediated by sensory stimuli that predominantly arise from nearby neighbors. But not all stimuli in animal groups are short range. Here, we consider mating swarms of midges, which interact primarily via long-range acoustic stimuli. We exploit the similarity in form between the decay of acoustic and gravitational sources to build a model for swarm behavior. By accounting for the adaptive nature of the midges' acoustic sensing, we show that our "adaptive gravity" model makes mean-field predictions that agree well with experimental observations of laboratory swarms. Our results highlight the role of sensory mechanisms and interaction range in collective animal behavior. The adaptive interactions that we present here open a new class of equations of motion, which may appear in other biological contexts.
Fermi-Pasta-Ulam model with long-range interactions: Dynamics and thermostatistics
Christodoulidi, H.; Tsallis, C.; Bountis, T.
2014-11-01
We study a long-range-interaction generalisation of the one-dimensional Fermi-Pasta-Ulam (FPU) β-model, by introducing a quartic interaction coupling constant that decays as 1/r^α (α ≥ 0) (with strength characterised by b > 0). In the α \\to∞ limit we recover the original FPU model. Through molecular dynamics we show that i) for α ≥ 1 the maximal Lyapunov exponent remains finite and positive for an increasing number of oscillators N, whereas, for 0 ≤ α 0 and δ >0 , in such a way that the q = 1 (BG) behaviour dominates in the \\limN \\to∞ \\limt \\to∞ ordering, while in the \\limt \\to∞ \\limN \\to∞ ordering q > 1 statistics prevails.
Casimir Effect as a Test for Thermal Corrections and Hypothetical Long-Range Interactions
Klimchitskaya, G L; Fischbach, E; Krause, D E; López, D; Mostepanenko, V M
2005-01-01
We have performed a precise experimental determination of the Casimir pressure between two gold-coated parallel plates by means of a micromachined oscillator. In contrast to all previous experiments on the Casimir effect, where a small relative error (varying from 1% to 15%) was achieved only at the shortest separation, our smallest experimental error ($\\sim 0.5$%) is achieved over a wide separation range from 170 nm to 300 nm at 95% confidence. We have formulated a rigorous metrological procedure for the comparison of experiment and theory without resorting to the previously used root-mean-square deviation, which has been criticized in the literature. This enables us to discriminate among different competing theories of the thermal Casimir force, and to resolve a thermodynamic puzzle arising from the application of Lifshitz theory to real metals. Our results lead to a more rigorous approach for obtaining constraints on hypothetical long-range interactions predicted by extra-dimensional physics and other exte...
Shiga toxin induces membrane reorganization and formation of long range lipid order
DEFF Research Database (Denmark)
Solovyeva, Vita; Johannes, Ludger; Simonsen, Adam Cohen
2015-01-01
membrane reordering. When Shiga toxin was added above the lipid chain melting temperature, the toxin interaction with the membrane induced rearrangement and clustering of Gb3 lipids that resulted in the long range order and alignment of lipids in gel domains. The toxin induced redistribution of Gb3 lipids...... microscopy. A content of 1% of glycosphingolipid globotriaosylceramide (Gb3) receptor lipids in a bilayer was used to bind the Shiga toxin B-subunit to the surface of gel domains. Binding of the Shiga toxin B-subunit to lipids led to the modulation of orientational membrane texture in gel domains and induced...... inside gel domains is governed by the temperature at which Shiga toxin was added to the membrane: above or below the phase transition. The temperature is thus one of the critical factors controlling lipid organization and texture in the presence of Shiga toxin. Lipid chain ordering imposed by Shiga toxin...
Symmetron Fields: Screening Long-Range Forces Through Local Symmetry Restoration
Hinterbichler, Kurt
2010-01-01
We present a novel screening mechanism that allows a scalar field to mediate a long range ~Mpc force of gravitational strength in the cosmos while satisfying local tests of gravity. The mechanism hinges on local symmetry restoration in the presence of matter. In regions of sufficiently high matter density, the field is drawn towards \\phi = 0 where its coupling to matter vanishes and the \\phi->-\\phi symmetry is restored. In regions of low density, however, the symmetry is spontaneously broken, and the field couples to matter with gravitational strength. We predict deviations from general relativity in the solar system that are within reach of next-generation experiments, as well as astrophysically observable violations of the equivalence principle. The model can be distinguished experimentally from Brans-Dicke gravity, chameleon theories and brane-world modifications of gravity.
Atmospheric emissions and long-range transport of persistent organic chemicals
Directory of Open Access Journals (Sweden)
Scheringer M.
2010-12-01
Full Text Available Persistent organic chemicals include several groups of halogenated compounds, such as polychlorinated biphenyls (PCBs, polybrominated diphenylethers (PBDEs, and polyfluorinated carboxylic acids (PFCAs. These chemicals remain for long times (years to decades in the environment and cycle between different media (air, water, sediment, soil, vegetation, etc.. The environmental distribution of this type of chemicals can conveniently be analyzed by multimedia models. Multimedia models consist of a set of coupled mass balance equations for the environmental media considered; they can be set up at various scales from local to global. Two applications of multimedia models to airborne chemicals are discussed in detail: the day-night cycle of PCBs measured in air near the surface, and the atmospheric long-range transport of volatile precursors of PFCAs, formation of PFCAs by oxidation of these precursors, and subsequent deposition of PFCAs to the surface in remote regions such as the Arctic.
Long-Range Corrected Hybrid Density Functionals with Damped Atom-Atom Dispersion Corrections
Energy Technology Data Exchange (ETDEWEB)
Chai, Jeng-Da; Head-Gordon, Martin
2008-06-14
We report re-optimization of a recently proposed long-range corrected (LC) hybrid density functionals [J.-D. Chai and M. Head-Gordon, J. Chem. Phys. 128, 084106 (2008)] to include empirical atom-atom dispersion corrections. The resulting functional, {omega}B97X-D yields satisfactory accuracy for thermochemistry, kinetics, and non-covalent interactions. Tests show that for non-covalent systems, {omega}B97X-D shows slight improvement over other empirical dispersion-corrected density functionals, while for covalent systems and kinetics, it performs noticeably better. Relative to our previous functionals, such as {omega}B97X, the new functional is significantly superior for non-bonded interactions, and very similar in performance for bonded interactions.
Prospects for bioenergy use in Ghana using Long-range Energy Alternatives Planning model
DEFF Research Database (Denmark)
Kemausuor, Francis; Nygaard, Ivan; Mackenzie, Gordon A.
2015-01-01
biomass sources, through the production of biogas, liquid biofuels and electricity. Analysis was based on moderate and high use of bioenergy for transportation, electricity generation and residential fuel using the LEAP (Long-range Energy Alternatives Planning) model. Results obtained indicate......As Ghana's economy grows, the choice of future energy paths and policies in the coming years will have a significant influence on its energy security. A Renewable Energy Act approved in 2011 seeks to encourage the influx of renewable energy sources in Ghana's energy mix. The new legal framework...... combined with increasing demand for energy has created an opportunity for dramatic changes in the way energy is generated in Ghana. However, the impending changes and their implication remain uncertain. This paper examines the extent to which future energy scenarios in Ghana could rely on energy from...
The Effect of a Long-Range Correlated-Hopping Interaction on Bariev Spin Chains
Directory of Open Access Journals (Sweden)
Tao Yang
2015-08-01
Full Text Available We introduce a long-range particle and spin interaction into the standard Bariev model and show that this interaction is equivalent to a phase shift in the kinetic term of the Hamiltonian. When the particles circle around the chain and across the boundary, the accumulated phase shift acts as a twist boundary condition with respect to the normal periodic boundary condition. This boundary phase term depends on the total number of particles in the system and also the number of particles in different spin states, which relates to the spin fluctuations in the system. The model is solved exactly via a unitary transformation by the coordinate Bethe ansatz. We calculate the Bethe equations and work out the energy spectrum with varying number of particles and spins.
Radioactive source localization inside pipes using a long-range alpha detector
Institute of Scientific and Technical Information of China (English)
WU Xue-Mei; TUO Xian-Guo; LI Zhe; LIU Ming-Zhe; ZHANG Jin-Zhao; DONG Xiang-Long; LI Ping-Chuan
2013-01-01
Long-range alpha detectors (LRADs) are attracting much attention in the decommissioning of nuclear facilities because of some problems in obtaining source positions on an interior surface during pipe decommissioning.By utilizing the characteristic that LRAD detects alphas by collecting air-driving ions,this article applies a method to localize the radioactive source by ions' fluid property.By obtaining the ion travel time and the airspeed distribution in the pipe,the source position can be determined.Thus this method overcomes the ion's lack of periodic characteristics.Experimental results indicate that this method can approximately localize the source inside the pipe.The calculation results are in good agreement with the experimental results.
Energy Technology Data Exchange (ETDEWEB)
Mendez, A. [Instituto de Fisica, Universidad Autonoma de Puebla, Apartado Postal J-48, Puebla 72570 (Mexico); Gopar, V. [Departamento de Fisica Teorica and Instituto de Biocomputacion y Fisica de Sistemas Complejos (BIFI), Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza (Spain); Varga, I. [Elmeleti Fizika Tanszek, Fizikai Intezet, Budapesti Mueszaki es Gazdasagtudomanyi Egyetem, 1521 Budapest (Hungary); Fachbereich Physik und Wissenschaftliches Zentrum fuer Materialwissenschaften, Philipps Universitaet Marburg, 35032 Marburg (Germany)
2009-12-15
We study numerically the conductance distribution function w(T) for the one-dimensional Anderson model with random long-range hopping described by the Power-law Banded Random Matrix model at criticality. We concentrate on the case of two single-channel leads attached to the system. We observe a smooth transition from localized to delocalized behavior in the conductance distribution by increasing b, the effective bandwidth of the model. Also, for b < 1 we show that w(ln T/T{sub typ}) is scale invariant, where T{sub typ} = exp left angle ln T right angle is the typical value of T. Moreover, we find that for T < T{sub typ}, w(ln T/T{sub typ}) shows a universal behavior proportional to (T/T{sub typ}){sup -1/2}. (Abstract Copyright [2009], Wiley Periodicals, Inc.)
Long-range correlation energy calculated from coupled atomic response functions
Ambrosetti, Alberto; DiStasio, Robert A; Tkatchenko, Alexandre
2013-01-01
An accurate determination of the electron correlation energy is essential for describing the structure, stability, and function in a wide variety of systems, ranging from gas-phase molecular assemblies to condensed matter and organic/inorganic interfaces. Even small errors in the correlation energy can have a large impact on the description of chemical and physical properties in the systems of interest. In this context, the development of efficient approaches for the accurate calculation of the long-range correlation energy (and hence dispersion) is the main challenge. In the last years a number of methods have been developed to augment density functional approximations via dispersion energy corrections, but most of these approaches ignore the intrinsic many-body nature of correlation effects, leading to inconsistent and sometimes even qualitatively incorrect predictions. Here we build upon the recent many-body dispersion (MBD) framework, which is intimately linked to the random-phase approximation for the co...
8th Annual report 1999. UN ECE convention on long-range transboundary air pollution
Energy Technology Data Exchange (ETDEWEB)
Kleemola, S.; Forsius, M. [eds.
1999-07-01
The Integrated Monitoring Programme (ICP IM) is part of the Effects Monitoring Strategy under the UN ECE Convention on Long-Range Transboundary Air Pollution. The main aim of ICP IM is to provide a framework to observe and understand the complex changes occurring in the external environment. This report summarizes the work carried out by the ICP IM Programme Centre and several collaborating institutes. The emphasis of the report is in the work done during the programme year 1998/99 including: - a short summary of previous data assessments - a short status report of the ICP IM activities, content of the IM database, and the present geographical coverage of the monitoring network - a documentation of the scientific strategies to carry out data assessment on two priority topics: - assessment of heavy metal pools and fluxes - assessment of cause-effect relationships for understorey vegetation - a description of the WATBAL-model for estimating monthly water balance components, including soil water fluxes. (orig.)
Viability assessment of bacteria using long-range surface plasmon waveguide biosensors
Béland, Paul; Berini, Pierre
2017-01-01
We demonstrate that long-range surface plasmon waveguide biosensors are useful to monitor the quiver of immobilized live bacteria in buffer and in human urine. First, the biosensor captures bacteria selectively, based on gram, using antibodies against gram adsorbed on the surface of the waveguide through Protein G coupling. Then, analysis of the noise present on the optical output signal reveals quiver of bacteria immobilized on the waveguide. Live bacteria produce a noisy signature compared to baseline levels. The standard deviation over time of the optical power output from the biosensor increased by factors of 3-60 over that of the baseline level for Staphylococcus epidermidis and Escherichia coli immobilized selectively on waveguides.
Evidence for a role of vertebrate Disp1 in long-range Shh signaling.
Etheridge, L Alton; Crawford, T Quinn; Zhang, Shile; Roelink, Henk
2010-01-01
Dispatched 1 (Disp1) encodes a twelve transmembrane domain protein that is required for long-range sonic hedgehog (Shh) signaling. Inhibition of Disp1 function, both by RNAi or dominant-negative constructs, prevents secretion and results in the accumulation of Shh in source cells. Measuring the Shh response in neuralized embryoid bodies (EBs) derived from embryonic stem (ES) cells, with or without Disp1 function, demonstrates an additional role for Disp1 in cells transporting Shh. Co-cultures with Shh-expressing cells revealed a significant reduction in the range of the contact-dependent Shh response in Disp1(-/-) neuralized EBs. These observations support a dual role for Disp1, not only in the secretion of Shh from the source cells, but also in the subsequent transport of Shh through tissue.
Helical configurations of elastic rods in the presence of a long-range interaction potential
Energy Technology Data Exchange (ETDEWEB)
De Lillo, S; Lupo, G; Sommacal, M, E-mail: Matteo.Sommacal@pg.infn.i [Dipartimento di Matematica e Informatica and INSTM-Village, Universita degli Studi di Perugia, Via Vanvitelli 1, 06123 Perugia (Italy)
2010-02-26
Recently, the integrability of the stationary Kirchhoff equations describing an elastic rod folded in the shape of a circular helix was proven. In this paper we explicitly work out the solutions to the stationary Kirchhoff equations in the presence of a long-range potential which describes the average constant force due to a Morse-type interaction acting among the points of the rod. The average constant force results to be parallel to the normal vector to the central line of the folded rod; this condition remarkably permits to preserve the integrability (indeed the solvability) of the corresponding Kirchhoff equations if the elastic rod features constant or periodic stiffnesses and vanishing intrinsic twist. Furthermore, we discuss the elastic energy density with respect to the radius and pitch of the helix, showing the existence of stationary points, namely stable and unstable configurations, for plausible choices of the featured parameters corresponding to a real bio-polymer.
Helical configurations of elastic rods in the presence of a long-range interaction potential
De Lillo, S.; Lupo, G.; Sommacal, M.
2010-02-01
Recently, the integrability of the stationary Kirchhoff equations describing an elastic rod folded in the shape of a circular helix was proven. In this paper we explicitly work out the solutions to the stationary Kirchhoff equations in the presence of a long-range potential which describes the average constant force due to a Morse-type interaction acting among the points of the rod. The average constant force results to be parallel to the normal vector to the central line of the folded rod; this condition remarkably permits to preserve the integrability (indeed the solvability) of the corresponding Kirchhoff equations if the elastic rod features constant or periodic stiffnesses and vanishing intrinsic twist. Furthermore, we discuss the elastic energy density with respect to the radius and pitch of the helix, showing the existence of stationary points, namely stable and unstable configurations, for plausible choices of the featured parameters corresponding to a real bio-polymer.
Long-range correlations and charge transport properties of DNA sequences
Energy Technology Data Exchange (ETDEWEB)
Liu Xiaoliang, E-mail: xlliucsu@yahoo.com.c [College of Physical Science and Technology and College of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Ren, Yi [College of Physical Science and Technology and College of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Xie, Qiong-tao [Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education (Hunan Normal University), Changsha 410081 (China); Deng, Chao-sheng; Xu, Hui [College of Physical Science and Technology and College of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China)
2010-04-26
By using Hurst's analysis and transfer approach, the rescaled range functions and Hurst exponents of human chromosome 22 and enterobacteria phage lambda DNA sequences are investigated and the transmission coefficients, Landauer resistances and Lyapunov coefficients of finite segments based on above genomic DNA sequences are calculated. In a comparison with quasiperiodic and random artificial DNA sequences, we find that lambda-DNA exhibits anticorrelation behavior characterized by a Hurst exponent 0.5
Common long-range dependence in a panel of hourly Nord Pool electricity prices and loads
DEFF Research Database (Denmark)
Ergemen, Yunus Emre; Haldrup, Niels; Rodríguez-Caballero, Carlos Vladimir
of the underlying production technology and because the demand is more volatile than the supply, equilibrium prices and loads are argued to identify the periodic power supply curve. The estimated supply elasticities are estimated from fractionally co-integrated relations and range between 0.5 and 1......Equilibrium electricity spot prices and loads are often determined simultaneously in a day-ahead auction market for each hour of the subsequent day. Hence daily observations of hourly prices take the form of a periodic panel rather than a time series of hourly observations. We consider novel panel...... data approaches to analyse the time series and the cross-sectional dependence of hourly Nord Pool electricity spot prices and loads for the period 2000-2013. Hourly electricity prices and loads data are characterized by strong serial long-range dependence in the time series dimension in addition...
Energy Technology Data Exchange (ETDEWEB)
Guo Aimin [Department of Physics Science and Technology, Central South University, Changsha 410083 (China)]. E-mail: guoaimin1982@163.com; Xu Hui [Department of Physics Science and Technology, Central South University, Changsha 410083 (China)
2007-04-01
Understanding the intrinsic conduction properties in DNA plays a vital role in molecular electronic engineering. We use a tight-binding model to investigate the transmissivity, Lyapunov coefficient and localization length of DNA, including periodic poly(G)-poly(C), quasiperiodic Fibonacci polyGC and random sequences, as a function of sequence length and temperature. Our results show that the periodicity and long-range correlations in DNA can persist high transmittivity, and new transmission peaks can appear for whatever the sequence length or temperature increases, but the mean transmission coefficient decreases. Meanwhile, thermal enhancement of conductance is a generic feature in all these sequences and the asymptotic behaviors of localization length for random DNA are in good agreement with the mobility edge theory.
Moslehi, Mahsa; de Barros, Felipe P. J.
2017-01-01
We investigate how the uncertainty stemming from disordered porous media that display long-range correlation in the hydraulic conductivity (K) field propagates to predictions of environmental performance metrics (EPMs). In this study, the EPMs are quantities that are of relevance to risk analysis and remediation, such as peak flux-averaged concentration, early and late arrival times among others. By using stochastic simulations, we quantify the uncertainty associated with the EPMs for a given disordered spatial structure of the K-field and identify the probability distribution function (PDF) model that best captures the statistics of the EPMs of interest. Results indicate that the probabilistic distribution of the EPMs considered in this study follows lognormal PDF. Finally, through the use of information theory, we reveal how the persistent/anti-persistent correlation structure of the K-field influences the EPMs and corresponding uncertainties.
Role of long-range intermolecular forces in the formation of inorganic nanoparticle clusters.
Gibbs, G V; Crawford, T D; Wallace, A F; Cox, D F; Parrish, R M; Hohenstein, E G; Sherrill, C D
2011-11-17
An understanding of the role played by intermolecular forces in terms of the electron density distribution is fundamental to the understanding of the self-assembly of molecules in the formation of a molecular crystal. Using ab initio methods capable of describing both short-range intramolecular interactions and long-range London dispersion interactions arising from electron correlation, analyses of inorganic dimers of As(4)S(4) and As(4)O(6) molecules cut from the structures of realgar and arsenolite, respectively, reveal that the molecules adopt a configuration that closely matches that observed for the crystal. Decomposition of the interaction energies using symmetry-adapted perturbation theory reveals that both model dimers feature significant stabilization from electrostatic forces as anticipated by a Lewis acid/Lewis base picture of the interaction. London dispersion forces also contribute significantly to the interaction, although they play a greater role in the realgar structure near equilibrium than in arsenolite.
Detection of dengue NS1 antigen using long-range surface plasmon waveguides.
Wong, Wei Ru; Sekaran, Shamala Devi; Adikan, Faisal Rafiq Mahamd; Berini, Pierre
2016-04-15
The non-structural 1 (NS1) protein of the dengue virus circulates in infected patients' blood samples and can be used for early diagnosis of dengue infection. In this paper, we present the detection of naturally-occurring dengue NS1 antigen in infected patient blood plasma using straight long-range surface plasmon waveguides. Three commercially-available anti-NS1 monoclonal antibodies were used for recognition and their performance was compared and discussed. A similar figure of merit to the one used in conventional dengue NS1 capture using an enzyme-linked immunosorbent assay (ELISA) was applied to our results. In general, the positive patient samples can be clearly differentiated from the negative ones and the results agree with those obtained using ELISA. The largest signal-to-noise ratio observed during the experiments was 356 and the best detection limit observed is estimated as 5.73 pg/mm(2).
Long-Range Wireless Mesh Network for Weather Monitoring in Unfriendly Geographic Conditions
Directory of Open Access Journals (Sweden)
Rafael E. Porrás-Trejo
2011-07-01
Full Text Available In this paper a long-range wireless mesh network system is presented. It consists of three main parts: Remote Terminal Units (RTUs, Base Terminal Units (BTUs and a Central Server (CS. The RTUs share a wireless network transmitting in the industrial, scientific and medical applications ISM band, which reaches up to 64 Km in a single point-to-point communication. A BTU controls the traffic within the network and has as its main task interconnecting it to a Ku-band satellite link using an embedded microcontroller-based gateway. Collected data is stored in a CS and presented to the final user in a numerical and a graphical form in a web portal.
Large magnetoresistance from long-range interface coupling in armchair graphene nanoribbon junctions
Energy Technology Data Exchange (ETDEWEB)
Li, Suchun [Department of Physics, Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 2 Science Drive 3, Singapore 117551 (Singapore); Institute of High Performance Computing, Agency for Science, Technology and Research, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632 (Singapore); NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 28 Medical Drive, Singapore 117456 (Singapore); Son, Young-Woo [Korea Institute for Advanced Study, Seoul 130-722 (Korea, Republic of); Quek, Su Ying, E-mail: phyqsy@nus.edu.sg [Department of Physics, Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 2 Science Drive 3, Singapore 117551 (Singapore); Institute of High Performance Computing, Agency for Science, Technology and Research, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632 (Singapore)
2014-12-15
In recent years, bottom-up synthesis procedures have achieved significant advancements in atomically controlled growth of several-nanometer-long graphene nanoribbons with armchair-shaped edges (AGNRs). This greatly encourages us to explore the potential of such well-defined AGNRs in electronics and spintronics. Here, we propose an AGNR based spin valve architecture that induces a large magnetoresistance up to 900%. We find that, when an AGNR is connected perpendicularly to zigzag-shaped edges, the AGNR allows for long-range extension of the otherwise localized edge state. The huge magnetoresistance is a direct consequence of the coupling of two such extended states from both ends of the AGNR, which forms a perfect transmission channel. By tuning the coupling between these two spin-polarized states with a magnetic field, the channel can be destroyed, leading to an abrupt drop in electron transmission.
Self-organized criticality in glassy spin systems requires long-range interactions
Andresen, Juan Carlos; Andrist, Ruben S.; Katzgraber, Helmut G.; Dobrosavljevic, Vladimir; Zimanyi, Gergerly T.
2013-03-01
We investigate the conditions required for general spin systems with frustration and disorder to display self-organized criticality, a property which so far has been established in spin models only for the infinite-range Sherringtion-Kirkpatrick Ising spin-glass model [PRL 83, 1034 (1999)]. We study the avalanche and the magnetization jump distribution triggered by an external magnetic field in the short-range Edward-Anderson Ising spin glass for various space dimensions, between 2 and 8. Our numerical results, obtained on systems of unprecedented size, demonstrate that self-organized criticality is recovered only in the strict limit of infinite space dimensions (or equivalently of long-ranged interaction), and is not a generic property of spin-glass models in finite space dimensions.
Amplitude equation and long-range interactions in underwater sand ripples in one dimension
DEFF Research Database (Denmark)
Schnipper, Teis; Mertens, Keith; Ellegaard, Clive;
2008-01-01
We present an amplitude equation for sand ripples under oscillatory flow in a situation where the sand is moving in a narrow channel and the height profile is practically one dimensional. The equation has the form h(t)=epsilon-(h-(h) over bar) + ((h(x))(2)-1)h(xx)-h(xxxx) + delta((h(x))(2))(xx) w...... finally present surprising experimental results showing that long-range coupling is indeed seen in the initial details of the doubling transition, where in fact two small ripples are initially formed, followed by global symmetry breaking removing one of them....... in particular on the so-called doubling transition, a secondary instability caused by the sudden decrease in the amplitude of the water motion, leading to the appearance of a new ripple in each trough. This transition is well reproduced for sufficiently large delta (asymmetry between trough and crest). We...
Ding, Zhenyang; Yao, X Steve; Liu, Tiegen; Du, Yang; Liu, Kun; Han, Qun; Meng, Zhuo; Chen, Hongxin
2012-12-17
We present a novel method to achieve a space-resolved long- range vibration detection system based on the correlation analysis of the optical frequency-domain reflectometry (OFDR) signals. By performing two separate measurements of the vibrated and non-vibrated states on a test fiber, the vibration frequency and position of a vibration event can be obtained by analyzing the cross-correlation between beat signals of the vibrated and non-vibrated states in a spatial domain, where the beat signals are generated from interferences between local Rayleigh backscattering signals of the test fiber and local light oscillator. Using the proposed technique, we constructed a standard single-mode fiber based vibration sensor that can have a dynamic range of 12 km and a measurable vibration frequency up to 2 kHz with a spatial resolution of 5 m. Moreover, preliminarily investigation results of two vibration events located at different positions along the test fiber are also reported.
Source areas and long-range transport of pollen from continental land to Tenerife (Canary Islands).
Izquierdo, Rebeca; Belmonte, Jordina; Avila, Anna; Alarcón, Marta; Cuevas, Emilio; Alonso-Pérez, Silvia
2011-01-01
The Canary Islands, due to their geographical position, constitute an adequate site for the study of long-range pollen transport from the surrounding land masses. In this study, we analyzed airborne pollen counts at two sites: Santa Cruz de Tenerife (SCO), at sea level corresponding to the marine boundary layer (MBL), and Izaña at 2,367 m.a.s.l. corresponding to the free troposphere (FT), for the years 2006 and 2007. We used three approaches to describe pollen transport: (1) a classification of provenances with an ANOVA test to describe pollen count differences between sectors; (2) a study of special events of high pollen concentrations, taking into consideration the corresponding meteorological synoptic pattern responsible for transport and back trajectories; and (3) a source-receptor model applied to a selection of the pollen taxa to show pollen source areas. Our results indicate several extra-regional pollen transport episodes to Tenerife. The main provenances were: (1) the Mediterranean region, especially the southern Iberian Peninsula and Morocco, through the trade winds in the MBL. These episodes were characterized by the presence of pollen from trees (Casuarina, Olea, Quercus perennial and deciduous types) mixed with pollen from herbs (Artemisia, Chenopodiaceae/Amaranthaceae and Poaceae wild type). (2) The Saharan sector, through transport at the MBL level carrying pollen principally from herbs (Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type) and, in one case, Casuarina pollen, uplifted to the free troposphere. And (3) the Sahel, characterized by low pollen concentrations of Arecaceae, Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type in sporadic episodes. This research shows that sporadic events of long-range pollen transport need to be taken into consideration in Tenerife as possible responsible agents in respiratory allergy episodes. In particular, it is estimated that 89-97% of annual counts of the highly allergenous Olea
Institute of Scientific and Technical Information of China (English)
ZHAO Wei; DING Jian-Wen
2011-01-01
We numerically investigate the normalized localization length of two-side rough nanowires as functions of energy, magnetic field and correlation strength by using modular recursive Green's function method. It is found that in the absence of correlation, while in the presence of magnetic Reid, the localization length increases linearly for two-side roughness, which is different to diverging exponentially for one-side roughness. Moreover, the localization of electrons is suppressed in the low energy region, but enhanced in the high energy region. In the presence of correlation, especially, an exponential enhancement in the localization length resumes in high energy region, in contrast to that in low energy region, the long-range correlations abnormally enhance the localization of electrons. A competitive mechanism is proposed to explain this behavior.%We numerically investigate the normalized localization length of two-side rough nanowires as functions of energy,magnetic field and correlation strength by using modular recursive Green's function method.It is found that in the absence of correlation,while in the presence of magnetic field,the localization length increases linearly for two-side roughness,which is different to diverging exponentially for one-side roughness.Moreover,the localization of electrons is suppressed in the low energy region,but enhanced in the high energy region.In the presence of correlation,especially,an exponential enhancement in the localization length resumes in high energy region,in contrast to that in low energy region,the long-range correlations abnormally enhance the localization of electrons.A competitive mechanism is proposed to explain this behavior.Quantum dynamics of quasiparticles in random media has been a field of extensive study since the pioneering work by Anderson,[1] who argued that quasiparticle states become localized for sufficiently large disorder,thus giving rise to a localizationdelocalization transition (LDT) in three
Effect of long-range repulsive Coulomb interactions on packing structure of adhesive particles.
Chen, Sheng; Li, Shuiqing; Liu, Wenwei; Makse, Hernán A
2016-02-14
The packing of charged micron-sized particles is investigated using discrete element simulations based on adhesive contact dynamic model. The formation process and the final obtained structures of ballistic packings are studied to show the effect of interparticle Coulomb force. It is found that increasing the charge on particles causes a remarkable decrease of the packing volume fraction ϕ and the average coordination number 〈Z〉, indicating a looser and chainlike structure. Force-scaling analysis shows that the long-range Coulomb interaction changes packing structures through its influence on particle inertia before they are bonded into the force networks. Once contact networks are formed, the expansion effect caused by repulsive Coulomb forces are dominated by short-range adhesion. Based on abundant results from simulations, a dimensionless adhesion parameter Ad*, which combines the effects of the particle inertia, the short-range adhesion and the long-range Coulomb interaction, is proposed and successfully scales the packing results for micron-sized particles within the latest derived adhesive loose packing (ALP) regime. The structural properties of our packings follow well the recent theoretical prediction which is described by an ensemble approach based on a coarse-grained volume function, indicating some kind of universality in the low packing density regime of the phase diagram regardless of adhesion or particle charge. Based on the comprehensive consideration of the complicated inter-particle interactions, our findings provide insight into the roles of short-range adhesion and repulsive Coulomb force during packing formation and should be useful for further design of packings.
Source areas and long-range transport of pollen from continental land to Tenerife (Canary Islands)
Izquierdo, Rebeca; Belmonte, Jordina; Avila, Anna; Alarcón, Marta; Cuevas, Emilio; Alonso-Pérez, Silvia
2011-01-01
The Canary Islands, due to their geographical position, constitute an adequate site for the study of long-range pollen transport from the surrounding land masses. In this study, we analyzed airborne pollen counts at two sites: Santa Cruz de Tenerife (SCO), at sea level corresponding to the marine boundary layer (MBL), and Izaña at 2,367 m.a.s.l. corresponding to the free troposphere (FT), for the years 2006 and 2007. We used three approaches to describe pollen transport: (1) a classification of provenances with an ANOVA test to describe pollen count differences between sectors; (2) a study of special events of high pollen concentrations, taking into consideration the corresponding meteorological synoptic pattern responsible for transport and back trajectories; and (3) a source-receptor model applied to a selection of the pollen taxa to show pollen source areas. Our results indicate several extra-regional pollen transport episodes to Tenerife. The main provenances were: (1) the Mediterranean region, especially the southern Iberian Peninsula and Morocco, through the trade winds in the MBL. These episodes were characterized by the presence of pollen from trees ( Casuarina, Olea, Quercus perennial and deciduous types) mixed with pollen from herbs ( Artemisia, Chenopodiaceae/Amaranthaceae and Poaceae wild type). (2) The Saharan sector, through transport at the MBL level carrying pollen principally from herbs (Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type) and, in one case, Casuarina pollen, uplifted to the free troposphere. And (3) the Sahel, characterized by low pollen concentrations of Arecaceae, Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type in sporadic episodes. This research shows that sporadic events of long-range pollen transport need to be taken into consideration in Tenerife as possible responsible agents in respiratory allergy episodes. In particular, it is estimated that 89-97% of annual counts of the highly allergenous Olea
Long range ultra-high frequency (UHF) radio frequency identification (RFID) antenna design
Reynolds, Nathan D.
There is an ever-increasing demand for radio frequency identification (RFID) tags that are passive, long range, and mountable on multiple surfaces. Currently, RFID technology is utilized in numerous applications such as supply chain management, access control, and public transportation. With the combination of sensory systems in recent years, the applications of RFID technology have been extended beyond tracking and identifying. This extension includes applications such as environmental monitoring and healthcare applications. The available sensory systems usually operate in the medium or high frequency bands and have a low read range. However, the range limitations of these systems are being overcome by the development of RFID sensors focused on utilizing tags in the ultra-high frequency (UHF) band. Generally, RFID tags have to be mounted to the object that is being identified. Often the objects requiring identification are metallic. The inherent properties of metallic objects have substantial effects on nearby electromagnetic radiation; therefore, the operation of the tag antenna is affected when mounted on a metallic surface. This outlines one of the most challenging problems for RFID systems today: the optimization of tag antenna performance in a complex environment. In this research, a novel UHF RFID tag antenna, which has a low profile, long range, and is mountable on metallic surfaces, is designed analytically and simulated using a 3-D electromagnetic simulator, ANSYS HFSS. A microstrip patch antenna is selected as the antenna structure, as patch antennas are low profile and suitable for mounting on metallic surfaces. Matching and theoretical models of the microstrip patch antenna are investigated. Once matching and theory of a microstrip patch antenna is thoroughly understood, a unique design technique using electromagnetic band gap (EBG) structures is explored. This research shows that the utilization of an EBG structure in the patch antenna design yields
Enhanced SO2 Concentrations Observed over Northern India: Role of Long-range Transport
Energy Technology Data Exchange (ETDEWEB)
Mallik, C.; Lal, S.; Naja, M.; Chand, Duli; Venkataramani, S.; Joshi, H.; Pant, P.
2013-01-17
Volcanic emissions and coal burning are among the major sources of SO2 over the continental environment. In this study, we show episodes of long-range transport of volcanic SO2 from Africa to Northern India using satellite observations. Monthly averaged SO2 from OMI were of the order of 0.6-0.9 DU during November, 2008 over the Indo-Gangetic Plain (IGP), which far exceeded background values (<0.3 DU) retrieved from observations across different locations over North India during 2005-2010. The columnar SO2 loadings were much higher on November 6 over most of the IGP and even exceeded 6 DU, a factor of 10 higher than background levels at some places. These enhanced SO2 levels were, however, not reciprocated in satellite derived NO2 or CO columns, indicating transport from a non-anthropogenic source of SO2. Backward trajectory analysis revealed strong winds in the free troposphere, which originated from the Dalaffilla volcanic eruption over the Afar region of Ethiopia during November 4-6, 2008. Wind streams and stable atmospheric conditions were conducive to the long-range transport of volcanic plume into the IGP. As most of the local aerosols over IGP region are below 3 km, a well separated layer at 4-5 km is observed from CALIPSO, most likely as a result of this transport. Apart from known anthropogenic sources, the additional transport of volcanic SO2 over the IGP region would have implications to air quality and radiation balance over this region.
Long- range transport of Xe-133 emissions under convective and non-convective conditions.
Kusmierczyk-Michulec, Jolanta; Gheddou, Abdelhakim
2015-04-01
The International Monitoring System (IMS) developed by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is a global system of monitoring stations, using four complementary technologies: seismic, hydroacoustic, infrasound and radionuclide. Data from all stations, belonging to IMS, are collected and transmitted to the International Data Centre (IDC) in Vienna, Austria. The radionuclide network comprises 80 stations, of which more than 60 are certified. The aim of radionuclide stations is a global monitoring of radioactive aerosols and radioactive noble gases, in particular xenon isotopes, supported by the atmospheric transport modeling (ATM). The aim of this study is to investigate the long-range transport of Xe-133 emissions under convective and non-convective conditions. For that purpose a series of 14 days forward simulations was conducted using the Lagrangian Particle Diffusion Model FLEXPART, designed for calculating the long-range and mesoscale dispersion of air pollution from point sources. The release point was at the ANSTO facility in Australia. The geographical localization to some extent justifies the assumption that the only source of Xe-133 observed at the neighbouring stations, comes from the ANSTO facility. In the simulations the analysed wind data provided by the European Centre for Medium-Range Weather Forecasts (ECMWF) were used with the spatial resolution of 0.5 degree. Studies have been performed to link Xe-133 emissions with detections at the IMS stations supported by the ATM, and to assess the impact of atmospheric convection on non-detections at the IMS stations. The results of quantitative and qualitative comparison will be presented.
Neuronal diversity in GABAergic long-range projections from the hippocampus.
Jinno, Shozo; Klausberger, Thomas; Marton, Laszlo F; Dalezios, Yannis; Roberts, J David B; Fuentealba, Pablo; Bushong, Eric A; Henze, Darrell; Buzsáki, György; Somogyi, Peter
2007-08-15
The formation and recall of sensory, motor, and cognitive representations require coordinated fast communication among multiple cortical areas. Interareal projections are mainly mediated by glutamatergic pyramidal cell projections; only few long-range GABAergic connections have been reported. Using in vivo recording and labeling of single cells and retrograde axonal tracing, we demonstrate novel long-range GABAergic projection neurons in the rat hippocampus: (1) somatostatin- and predominantly mGluR1alpha-positive neurons in stratum oriens project to the subiculum, other cortical areas, and the medial septum; (2) neurons in stratum oriens, including somatostatin-negative ones; and (3) trilaminar cells project to the subiculum and/or other cortical areas but not the septum. These three populations strongly increase their firing during sharp wave-associated ripple oscillations, communicating this network state to the septotemporal system. Finally, a large population of somatostatin-negative GABAergic cells in stratum radiatum project to the molecular layers of the subiculum, presubiculum, retrosplenial cortex, and indusium griseum and fire rhythmically at high rates during theta oscillations but do not increase their firing during ripples. The GABAergic projection axons have a larger diameter and thicker myelin sheet than those of CA1 pyramidal cells. Therefore, rhythmic IPSCs are likely to precede the arrival of excitation in cortical areas (e.g., subiculum) that receive both glutamatergic and GABAergic projections from the CA1 area. Other areas, including the retrosplenial cortex, receive only rhythmic GABAergic CA1 input. We conclude that direct GABAergic projections from the hippocampus to other cortical areas and the septum contribute to coordinating oscillatory timing across structures.
Color signal integration for color discrimination along a long-range apparent motion trajectory.
Nagai, Takehiro; Kimura, Hiroto; Nakauchi, Shigeki
2013-01-01
In contrast to the classical view that fundamental visual attributes such as color and motion are independently processed in the visual system (e.g. Livingstone and Hubel, 1987; Marr, 1982), recent studies have revealed various forms of cross-attribute interactions, such as averaging of color appearance along the motion trajectory of an object (Nishida et al., 2007). In this study, we investigated whether such color signal integration along a motion trajectory can be induced only by motion mechanisms having large receptive fields, without simple integration within direction-selective neurons with small receptive fields, like those in V1. The stimulus consisted of discs with long-range apparent motion along a circular trajectory. The stimulus onset asynchrony (SOA) between disc presentations controlled the strength of the apparent motion perception. We measured observers' sensitivity in detecting color modulation on the discs. The results showed that the measured sensitivity was lowest at SOAs corresponding to the strongest motion perception. This can be interpreted as follows: color signals were integrated along an apparent motion path, and this integration reduced chromatic sensitivity by averaging color signals. Another experiment that controlled apparent motion perception in a different way also supported this idea. However, this integration effect seemed to be linked to responses of motion detectors for the apparent motion stimuli, not directly to perceptual motion representation in the visual system. These results suggest that the human visual system handles color information from retinal inputs regarding moving objects based not only on a retinotopic coordinate but also on object-based coordinates, even when the moving object yields only long-range apparent motion.
Thioarsenides: A case for long-range Lewis acid-base-directed van der Waals interactions
Energy Technology Data Exchange (ETDEWEB)
Gibbs, Gerald V.; Wallace, Adam F.; Downs, R. T.; Ross, Nancy L.; Cox, David F.; Rosso, Kevin M.
2011-04-01
Electron density distributions, bond paths, Laplacian and local energy density properties have been calculated for a number of As4Sn (n = 3,4,5) thioarsenide molecular crystals. On the basis of the distributions, the intramolecular As-S and As-As interactions classify as shared bonded interactions and the intermolecular As-S, As-As and S-S interactions classify as closed-shell van der Waals bonded interactions. The bulk of the intermolecular As-S bond paths link regions of locally concentrated electron density (Lewis base regions) with aligned regions of locally depleted electron density (Lewis acid regions) on adjacent molecules. The paths are comparable with intermolecular paths reported for several other molecular crystals that link aligned Lewis base and acid regions in a key-lock fashion, interactions that classified as long range Lewis acid-base directed van der Waals interactions. As the bulk of the intermolecular As-S bond paths (~70%) link Lewis acid-base regions on adjacent molecules, it appears that molecules adopt an arrangement that maximizes the number of As-S Lewis acid-base intermolecular bonded interactions. The maximization of the number of Lewis acid-base interactions appears to be connected with the close-packed array adopted by molecules: distorted cubic close-packed arrays are adopted for alacránite, pararealgar, uzonite, realgar and β-AsS and the distorted hexagonal close-packed arrays adopted by α- and β-dimorphite. A growth mechanism is proposed for thioarsenide molecular crystals from aqueous species that maximizes the number of long range Lewis acid-base vdW As-S bonded interactions with the resulting directed bond paths structuralizing the molecules as a molecular crystal.
Zhao, Xiangai; Kim, Seung-Kyu; Zhu, Weihong; Kannan, Narayanan; Li, Donghao
2015-01-01
The Changbai (also known as "Baekdu") Mountain, on the border between China and North Korea, is the highest mountain (2750 m) in northeastern China. Recently, this mountain region has experienced a dramatic increase in air pollution, not only because of increasing volumes of tourism-derived traffic but also because of the long-range transport of polluted westerly winds passing through major industrial and urban cities in the eastern region of China. To assess the relative importance of the two sources of pollution, 16 polycyclic aromatic hydrocarbons (PAHs) as model substances were determined in the mountain soil. A total of 32 soil samples were collected from different sides of the mountain at different latitudes between July and August of 2009. The ∑PAH concentrations were within the range 38.5-190.1 ng g(-1) on the northern side, 117.7-443.6 ng g(-1) on the southern side, and 75.3-437.3 ng g(-1) on the western side. A progressive increase in the level of ∑PAHs with latitude was observed on the southern and western sides that face the westerly wind with abundant precipitation. However, a similar concentration gradient was not observed on the northern side that receives less rain and is on the leeward direction of the wind. The high-molecular-weight PAH compounds were predominant in the soils on the southern and western sides, while low-molecular-weight PAHs dominated the northern side soils. These findings show that the distribution of PAHs in the mountain soil is strongly influenced by the atmospheric long-range transport and cold trapping.
Long-range transport of terrain-induced turbulence from high-resolution numerical simulations
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M. Katurji
2011-03-01
Full Text Available Over complex terrain, an important question is how various topographic features may generate or alter wind turbulence and how far the influence can be extended downstream. Current measurement technology limits the capability in providing a long-range snapshot of turbulence as atmospheric eddies travel over terrain, interact with each other, change their productive and dissipative properties, and are then observed tens of kilometers downstream of their source.In this study, we investigate through high-resolutionnumerical simulations the atmospheric transport of terrain-generated turbulence in an atmosphere that is neutrally stratified. The simulations are two-dimensional with an isotropic spatial resolution of 15 m and run to a quasi-steady state. They are designed in such a way to allow an examination of the effects of a bell-shaped experimental hill with varying height and aspect ratio on turbulence properties generated by another hill 20 km upstream. Averaged fields of the turbulent kinetic energy (TKE implythat terrain could have a large influence on velocity perturbations at least 30 H (H is the terrain height upstream and downstream of the terrain, with the largest effect happening in the area of the largest pressure perturbations. The results also show that downstream of the terrain the TKE fields are sensitive to the terrain's aspect ratio with larger enhancement in turbulence by higher aspect ratio, while upstream there is a suppression of turbulence that does not appear to be sensitive to the terrain aspect ratio. Instantaneous vorticity fields shows very detailed flow structures that resemble a multitude of eddy scales dynamically interacting while shearing oppositely paired vortices. The knowledge of the turbulence production and modifications by topography from these high-resolutionsimulationscan be helpful in understanding long-range terrain-induced turbulence and improving turbulence parameterizations used in lower
Long-range transport of terrain-induced turbulence from high-resolution numerical simulations
Directory of Open Access Journals (Sweden)
M. Katurji
2011-11-01
Full Text Available Over complex terrain, an important question is how various topographic features may generate or alter wind turbulence and how far the influence can be extended downstream. Current measurement technology limits the capability in providing a long-range snapshot of turbulence as atmospheric eddies travel over terrain, interact with each other, change their productive and dissipative properties, and are then observed tens of kilometers downstream of their source. In this study, we investigate through high-resolution numerical simulations the atmospheric transport of terrain-generated turbulence in an atmosphere that is neutrally stratified. The simulations are two-dimensional with an isotropic spatial resolution of 15 m and run to a quasi-steady state. They are designed in such a way to allow an examination of the effects of a bell-shaped experimental hill with varying height and aspect ratio on turbulence properties generated by another hill 20 km upstream. Averaged fields of the turbulent kinetic energy (TKE imply that terrain could have a large influence on velocity perturbations at least 30H (H is the terrain height upstream and downstream of the terrain, with the largest effect happening in the area of the largest pressure perturbations. The results also show that downstream of the terrain the TKE fields are sensitive to the terrain's aspect ratio with larger enhancement in turbulence by higher aspect ratio, while upstream there is a suppression of turbulence that does not appear to be sensitive to the terrain aspect ratio. Instantaneous vorticity fields shows very detailed flow structures that resemble a multitude of eddy scales dynamically interacting while shearing oppositely paired vortices. The knowledge of the turbulence production and modifications by topography from these high-resolution simulations can be helpful in understanding long-range terrain-induced turbulence and improving turbulence parameterizations used in
Atmospheric Modelling of Aerosols Long-Range Transport over the Himalayas
Surapipith, V.; Adhikary, B.; Bhave, P.; Panday, A. K.; Mukherji, A.
2014-12-01
An Atmospheric Modelling System has been set up at International Centre for Integrated Mountain Development (ICIMOD) Headquarters in Kathmandu, Nepal, for the assessment of air quality in the Hindukush Himalaya region. The Weather Research and Forecasting with Chemistry (WRF-Chem) model version 3.6 is being implemented over a regional domain stretching across 4995 x 4455 km centred at Kathmandu, where an intensive field campaign, Sustainable Atmosphere for the Kathmandu Valley (SusKat) took place from December 2012 to February 2013. Seven stations around the valley collected data on meteorology and chemical parameters. WRF-Chem simulation are carried out for the winter time period at high horizontal resolution (1 km × 1 km), which is achieved by nesting the domain of interest, e.g. Kathmandu Valley, inside three coarser domains. Model validation is performed against the field data as well as satellite data, focusing on aerosols. The challenge of capturing the necessary atmospheric processes is discussed. The effort aims for a better understanding of atmospheric processes and aerosol impacts, as well as the impact of long-range transport, particularly of black carbon aerosol upon the radiative budget over the Himalayan glaciers. The rapid melting of Himalayan glaciers and snowfields, and the shrinkage of permafrost as noticed by glaciologists is a concern. Based on physically adjusted schemes, the WRF meteorological model performs well with Pearson correlation coefficients higher than 0.8 for temperature and solar radiation, although it has a tendency to overestimate wind speed. The WRF with chemistry is then used with local and regional emission databases, in combination and after comparison with the global inventory, as input for describing the long-range transport of aerosols. Improved aerosol prediction will allow us to provide crucial information needed for mitigation and adaptation strategies that save people's lives across the Himalaya. The regional
Long-range energy transfer in self-assembled quantum dot-DNA cascades
Goodman, Samuel M.; Siu, Albert; Singh, Vivek; Nagpal, Prashant
2015-11-01
The size-dependent energy bandgaps of semiconductor nanocrystals or quantum dots (QDs) can be utilized in converting broadband incident radiation efficiently into electric current by cascade energy transfer (ET) between layers of different sized quantum dots, followed by charge dissociation and transport in the bottom layer. Self-assembling such cascade structures with angstrom-scale spatial precision is important for building realistic devices, and DNA-based QD self-assembly can provide an important alternative. Here we show long-range Dexter energy transfer in QD-DNA self-assembled single constructs and ensemble devices. Using photoluminescence, scanning tunneling spectroscopy, current-sensing AFM measurements in single QD-DNA cascade constructs, and temperature-dependent ensemble devices using TiO2 nanotubes, we show that Dexter energy transfer, likely mediated by the exciton-shelves formed in these QD-DNA self-assembled structures, can be used for efficient transport of energy across QD-DNA thin films.The size-dependent energy bandgaps of semiconductor nanocrystals or quantum dots (QDs) can be utilized in converting broadband incident radiation efficiently into electric current by cascade energy transfer (ET) between layers of different sized quantum dots, followed by charge dissociation and transport in the bottom layer. Self-assembling such cascade structures with angstrom-scale spatial precision is important for building realistic devices, and DNA-based QD self-assembly can provide an important alternative. Here we show long-range Dexter energy transfer in QD-DNA self-assembled single constructs and ensemble devices. Using photoluminescence, scanning tunneling spectroscopy, current-sensing AFM measurements in single QD-DNA cascade constructs, and temperature-dependent ensemble devices using TiO2 nanotubes, we show that Dexter energy transfer, likely mediated by the exciton-shelves formed in these QD-DNA self-assembled structures, can be used for efficient
Long range thermal weapon sights for the German future infantryman program IdZ
Breiter, Rainer; Ihle, Tobias; Mauk, Karl-Heinz; Münzberg, Mario; Rode, Werner
2007-04-01
In December 2004 AIM started the series production of the HuntIR long range thermal weapon sight. The sight is fielded in the Germany Future Infantryman (IdZ) basic system and since that time in continuous service in various out of area missions with German participation. For very long identification ranges >1500m cooled technology still outperforms uncooled sights, even with respect to smaller size and lower weight because the typical F/1 design of uncooled systems overcompensates cooler weight for focal length >175mm. The HuntIR sight is therefore based on a cooled MWIR detection module for long range battlefield surveillance and target engagement. The device specifically is a perfect match to state of the art small arms like 0.50 cal sniper rifles or crew served weapons like the 40mm high velocity grenade machine gun (GMG) which provide engagement ranges >1500m and need an adequate sight performance beyond that. A recent modification of HuntIR was done to provide a wider field of view for improved situation awareness in urban operations and specifically to allow the engagement of the 40mm GMG in ranges between 250-1200m. The qualification tests of the sight by the German infantry were successfully completed mid 2006. To match the demand of the follow-up program IdZ-ES additional components have to be integrated. Most important are a laser range finder (LRF), 3 axis digital magnetic compass (DMC) and a wireless data link. LRF and DMC together with a highly sophisticated fire control computer provide improved first round hit probability, the DMC additionally improves the fire control in any case of steep trajectories or for pronounced ballistic trajectories to avoid any need to precisely level the GMG. This new sight is done under the brand name RangIR. An important additional feature is the interface for air burst ammunition (ABM). The optical distance is measured by the LRF, the fire control computer accurately evaluates the trajectory under the given angle
Long-Range Correlations in the Sequence of Human Heartbeats and Other Biological Signals
Teich, Malvin C.
1998-03-01
The sequence of heartbeat occurrence times provides information about the state of health of the heart. We used a variety of measures, including multiresolution wavelet analysis, to identify the form of the point process that describes the human heartbeat. These measures, which are based on both interbeat (R-R) intervals and counts (heart rate), have been applied to records for both normal and heart-failure patients drawn from a standard database, and various surrogate versions thereof. Several of these measures reveal scaling behavior (1/f-type fluctuations; long-range power-law correlations).(R. G. Turcott and M. C. Teich, Proc. SPIE) 2036 (Chaos in Biology and Medicine), 22--39 (1993). Essentially all of the R-R and count-based measures we investigated, including those that exhibit scaling, differ in statistically significant ways for the normal and heart-failure patients. The wavelet measures, however, reveal a heretofore unknown scale window, between 16 and 32 heartbeats, over which the magnitudes of the wavelet-coefficient variances fall into disjoint sets for the normal and heart-failure patients.(R. G. Turcott and M. C. Teich, Ann. Biomed. Eng.) 24, 269--293 (1996).^,(S. Thurner, M. C. Feurstein, and M. C. Teich, Phys. Rev. Lett.) (in press). This enables us to correctly classify every patient in the standard data set as either belonging to the heart-failure or normal group with 100% accuracy, thereby providing a clinically significant measure of the presence of heart-failure. Previous approaches have provided only statistically significant measures. The tradeoff between sensitivity and specificity for various salient measures, as a function of data length, is determined by the use of ROC analysis. A phase-space reconstruction based on generalized heart rate is used to obtain a putative attractor's capacity dimension. Though the dependence of this dimension on the embedding dimension is consistent with that of a low-dimensional dynamical system, surrogate
Study of the confined Ising magnet with long-range competing boundary fields
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Virgiliis, Andres de [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), UNLP, CONICET, Casilla de Correo 16, Sucursal 4 (1900) La Plata (Argentina); Institut fuer Physik, Johannes Gutenberg Universitaet, Staudingerweg 7, D-55099 Mainz (Germany); Albano, Ezequiel V [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), UNLP, CONICET, Casilla de Correo 16, Sucursal 4 (1900) La Plata (Argentina); Institut fuer Physik, Johannes Gutenberg Universitaet, Staudingerweg 7, D-55099 Mainz (Germany); Mueller, Marcus [Institut fuer Physik, Johannes Gutenberg Universitaet, Staudingerweg 7, D-55099 Mainz (Germany); Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706-1390 (United States); Binder, Kurt [Institut fuer Physik, Johannes Gutenberg Universitaet, Staudingerweg 7, D-55099 Mainz (Germany)
2005-07-27
We present extensive Monte Carlo simulations of the Ising film confined in an L ? M geometry (L << M) in the presence of long-range competing magnetic fields h(n) = h{sub 1}/n{sup 3}(n = 1,2,...,L) which are applied at opposite walls along the M-direction. Due to the fields, an interface between domains of different orientations that runs parallel to the walls forms and can be located close to one of the two surfaces or fluctuate in the centre of the film (localization-delocalization transition). This transition is the precursor of the wetting phase transition that occurs in the limit of infinite film thickness (L {yields} {infinity}) at the critical curve T{sub w}(h{sub 1}). For T
Yamasaki, Kazuo; Daiho, Takashi; Danko, Stefania; Suzuki, Hiroshi
2013-07-12
Sarcoplasmic reticulum Ca(2+)-ATPase couples the motions and rearrangements of three cytoplasmic domains (A, P, and N) with Ca(2+) transport. We explored the role of electrostatic force in the domain dynamics in a rate-limiting phosphoenzyme (EP) transition by a systematic approach combining electrostatic screening with salts, computer analysis of electric fields in crystal structures, and mutations. Low KCl concentration activated and increasing salt above 0.1 m inhibited the EP transition. A plot of the logarithm of the transition rate versus the square of the mean activity coefficient of the protein gave a linear relationship allowing division of the activation energy into an electrostatic component and a non-electrostatic component in which the screenable electrostatic forces are shielded by salt. Results show that the structural change in the transition is sterically restricted, but that strong electrostatic forces, when K(+) is specifically bound at the P domain, come into play to accelerate the reaction. Electric field analysis revealed long-range electrostatic interactions between the N and P domains around their hinge. Mutations of the residues directly involved and other charged residues at the hinge disrupted in parallel the electric field and the structural transition. Favorable electrostatics evidently provides a low energy path for the critical N domain motion toward the P domain, overcoming steric restriction. The systematic approach employed here is, in general, a powerful tool for understanding the structural mechanisms of enzymes.
Directory of Open Access Journals (Sweden)
A. D. Clarke
2013-08-01
Full Text Available Airborne aerosol measurements in the central equatorial Pacific during PASE (Pacific Atmospheric Sulfur Experiment revealed that cloud condensation nuclei (CCN activated in marine boundary layer (MBL clouds were strongly influenced by entrainment from the free troposphere (FT. About 65% entered at sizes effective as CCN in MBL clouds, while ~25% entered the MBL too small to activate but subsequently grew via gas to particle conversion. The remaining ~10% were inferred to be sea salt aerosol. FT aerosols at low carbon monoxide (CO mixing ratios ( The observed FT transport over thousands of kilometers indicates teleconnections between MBL CCN and cloud-scavenged sources of both natural and/or residual combustion origin. Nonetheless, in spite of its importance, this source of CCN number is not well represented in most current models and is generally not detectable by satellite because of the low aerosol scattering in such layers as a result of cloud scavenging. In addition, our measurements confirm nucleation in the MBL was not evident during PASE and argue against a localized linear relation in the MBL between dimethyl sulfide (DMS and CCN suggested by the CLAW hypothesis. However, when the FT is not impacted by long-range transport, sulfate aerosol derived from DMS pumped aloft in the ITCZ (Inter-Tropical Convergence Zone can provide a source of CCN to the boundary layer via FT teleconnections involving more complex non-linear processes.
Fang, Fang; Xu, Yifeng; Chew, Kai-Khen; Chen, Xi; Ng, Huck-Hui; Matsudaira, Paul
2014-07-01
Master transcription factors Oct4, Sox2, and Nanog are required to maintain the pluripotency and self-renewal of embryonic stem cells (ESCs) by regulating a specific transcriptional network. A few other transcription factors have been shown to be important in ESCs by interacting with these master transcription factors; however, little is known about the transcriptional mechanisms regulated by coregulators (coactivators and corepressors). In this study, we examined the function of two highly homologous coactivators, p300 and CREB-binding protein (CBP), in ESCs. We find that these two coactivators play redundant roles in maintaining the undifferentiated state of ESCs. They are recruited by Nanog through physical interaction to Nanog binding loci, mediating the formation of long-range chromatin looping structures, which is essential to maintain ESC-specific gene expression. Further functional studies reveal that the p300/CBP binding looping fragments contain enhancer activities, suggesting that the formation of p300/CBP-mediated looping structures may recruit distal enhancers to create a concentration of factors for the transcription activation of genes that are involved in self-renewal and pluripotency. Overall, these results provide a total new insight into the transcriptional regulation mechanism of coactivators p300 and CBP in ESCs, which is important in maintaining self-renewal and pluripotency, by mediating the formation of higher order chromosome structures.
Mellem, Monika S; Friedman, Rhonda B; Medvedev, Andrei V
2013-12-01
Anterior and posterior brain areas are involved in the storage and retrieval of semantic representations, but it is not known how these areas dynamically interact during semantic processing. We hypothesized that long-range theta-band coherence would reflect coupling of these areas and examined the oscillatory dynamics of lexical-semantic processing using a semantic priming paradigm with a delayed letter-search task while recording subjects' EEG. Time-frequency analysis revealed facilitation of semantic processing for Related compared to Unrelated conditions, which resulted in a reduced N400 and reduced gamma power from 150 to 450ms. Moreover, we observed greater anterior-posterior theta coherence for Unrelated compared to Related conditions over the time windows 150-425ms and 600-900ms. We suggest that while gamma power reflects activation of local functional networks supporting semantic representations, theta coherence indicates dynamic coupling of anterior and posterior areas for retrieval and post-retrieval processing and possibly an interaction between semantic relatedness and working memory.
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García-Torres, Itzhel; Cabrera, Nallely; Torres-Larios, Alfredo; Rodríguez-Bolaños, Mónica; Díaz-Mazariegos, Selma; Gómez-Puyou, Armando; Perez-Montfort, Ruy (UNAM-Mexico)
2012-04-02
For a better comprehension of the structure-function relationship in proteins it is necessary to identify the amino acids that are relevant for measurable protein functions. Because of the numerous contacts that amino acids establish within proteins and the cooperative nature of their interactions, it is difficult to achieve this goal. Thus, the study of protein-ligand interactions is usually focused on local environmental structural differences. Here, using a pair of triosephosphate isomerase enzymes with extremely high homology from two different organisms, we demonstrate that the control of a seventy-fold difference in reactivity of the interface cysteine is located in several amino acids from two structurally unrelated regions that do not contact the cysteine sensitive to the sulfhydryl reagent methylmethane sulfonate, nor the residues in its immediate vicinity. The change in reactivity is due to an increase in the apparent pKa of the interface cysteine produced by the mutated residues. Our work, which involved grafting systematically portions of one protein into the other protein, revealed unsuspected and multisite long-range interactions that modulate the properties of the interface cysteines and has general implications for future studies on protein structure-function relationships.
Gladilin, Evgeny
2017-01-01
Malignant transformation is known to involve substantial rearrangement of the molecular genetic landscape of the cell. A common approach to analysis of these alterations is a reductionist one and consists of finding a compact set of differentially expressed genes or associated signaling pathways. However, due to intrinsic tumor heterogeneity and tissue specificity, biomarkers defined by a small number of genes/pathways exhibit substantial variability. As an alternative to compact differential signatures, global features of genetic cell machinery are conceivable. Global network descriptors suggested in previous works are, however, known to potentially be biased by overrepresentation of interactions between frequently studied genes-proteins. Here, we construct a cellular network of 74538 directional and differential gene expression weighted protein-protein and gene regulatory interactions, and perform graph-theoretical analysis of global human interactome using a novel, degree-independent feature-the normalized total communicability (NTC). We apply this framework to assess differences in total information flow between different cancer (BRCA/COAD/GBM) and non-cancer interactomes. Our experimental results reveal that different cancer interactomes are characterized by significant enhancement of long-range NTC, which arises from circulation of information flow within robustly organized gene subnetworks. Although enhancement of NTC emerges in different cancer types from different genomic profiles, we identified a subset of 90 common genes that are related to elevated NTC in all studied tumors. Our ontological analysis shows that these genes are associated with enhanced cell division, DNA replication, stress response, and other cellular functions and processes typically upregulated in cancer. We conclude that enhancement of long-range NTC manifested in the correlated activity of genes whose tight coordination is required for survival and proliferation of all tumor cells
Long-range oncogenic activation of Igh-c-myc translocations by the Igh 3' regulatory region.
Gostissa, Monica; Yan, Catherine T; Bianco, Julia M; Cogné, Michel; Pinaud, Eric; Alt, Frederick W
2009-12-10
B-cell malignancies, such as human Burkitt's lymphoma, often contain translocations that link c-myc or other proto-oncogenes to the immunoglobulin heavy chain locus (IgH, encoded by Igh). The nature of elements that activate oncogenes within such translocations has been a long-standing question. Translocations within Igh involve DNA double-strand breaks initiated either by the RAG1/2 endonuclease during variable, diversity and joining gene segment (V(D)J) recombination, or by activation-induced cytidine deaminase (AID, also known as AICDA) during class switch recombination (CSR). V(D)J recombination in progenitor B (pro-B) cells assembles Igh variable region exons upstream of mu constant region (Cmu) exons, which are the first of several sets of C(H) exons ('C(H) genes') within a C(H) locus that span several hundred kilobases (kb). In mature B cells, CSR deletes Cmu and replaces it with a downstream C(H) gene. An intronic enhancer (iEmu) between the variable region exons and Cmu promotes V(D)J recombination in developing B cells. Furthermore, the Igh 3' regulatory region (Igh3'RR) lies downstream of the C(H) locus and modulates CSR by long-range transcriptional enhancement of C(H) genes. Transgenic mice bearing iEmu or Igh3'RR sequences fused to c-myc are predisposed to B lymphomas, demonstrating that such elements can confer oncogenic c-myc expression. However, in many B-cell lymphomas, Igh-c-myc translocations delete iEmu and place c-myc up to 200 kb upstream of the Igh3'RR. Here we address the oncogenic role of the Igh3'RR by inactivating it in two distinct mouse models for B-cell lymphoma with Igh-c-myc translocations. We show that the Igh3'RR is dispensable for pro-B-cell lymphomas with V(D)J recombination-initiated translocations, but is required for peripheral B-cell lymphomas with CSR-associated translocations. As the Igh3'RR is not required for CSR-associated Igh breaks or Igh-c-myc translocations in peripheral B-cell lymphoma progenitors, we conclude that
Polymer Conjugation as a Strategy for Long-Range Order in Supramolecular Polymers.
Benjamin, Ari; Keten, Sinan
2016-04-01
Supramolecular polymers are polymers in which the individual subunits self-assemble via noncovalent and reversible bonds. An important axis of control for systems of mixed subunit composition is the order in which the subunit types assemble. Existing ordering techniques, which rely on pairwise interactions through the inclusion of highly specific chemistry, have the downside that patterns of length n require n specific chemistries, making long-range order complicated to attain. Here we present a simple alternative method: we attach varying numbers of polymers to self-assembling subunits, in our case ring shaped macrocycles, and the polymers' aversion to confinement imposes system order. We evaluate the feasibility of the strategy using coarse-grained molecular dynamics simulations of polymer-conjugated rings designed to model cyclic peptide nanotubes. We discuss the effects of polymer conjugation on the energetics of association and predict the equilibrium orderings for various ratios of ring types. The emergent patterns are associated with a certain stochastic disorder, which we quantify by deriving and employing a formula for the expected statistical weight of any pattern within the ensemble of all possible orderings.
Directory of Open Access Journals (Sweden)
Stefano Piana
Full Text Available The use of molecular dynamics simulations to provide atomic-level descriptions of biological processes tends to be computationally demanding, and a number of approximations are thus commonly employed to improve computational efficiency. In the past, the effect of these approximations on macromolecular structure and stability has been evaluated mostly through quantitative studies of small-molecule systems or qualitative observations of short-timescale simulations of biological macromolecules. Here we present a quantitative evaluation of two commonly employed approximations, using a test system that has been the subject of a number of previous protein folding studies--the villin headpiece. In particular, we examined the effect of (i the use of a cutoff-based force-shifting technique rather than an Ewald summation for the treatment of electrostatic interactions, and (ii the length of the cutoff used to determine how many pairwise interactions are included in the calculation of both electrostatic and van der Waals forces. Our results show that the free energy of folding is relatively insensitive to the choice of cutoff beyond 9 Å, and to whether an Ewald method is used to account for long-range electrostatic interactions. In contrast, we find that the structural properties of the unfolded state depend more strongly on the two approximations examined here.
Long-range correlations in remotely sensed chlorophyll in the South China Sea
Institute of Scientific and Technical Information of China (English)
ZHAN Haigang; SHI Ping; MAO Qinwen; ZHANG Tonghui
2006-01-01
A 8-year time series of 8-day Seaviewing Wide Field-of-view Sensor (SeaWiFS) data,which spans from Oct 1997 to Oct 2005, was used to study the temporal correlations and scaling behaviour of ocean chlorophyll fluctuations in the South China Sea (SCS) by means of detrended fluctuation analysis (DFA). Long-range correlations in chlorophyll fluctuations were detected in almost all the SCS. The scaling exponents vary over a wide range from 0.5 to 1.14, with an average value of 0.79. High values are found in the upwelling regions, such as the northwest of Luzon and the north of Sunda Shelf. Low values occur in the southwest of Luzon, the east of Hainan Island and a majority of the southern SCS. This spatial pattern is considerably different from that of the scaling exponents of the sea surface temperature (SST) time series. It is also demonstrated that SST exhibits more persistence than chlorophyll in almost all the SCS.
HAMP – the microwave package on the High Altitude and LOng range research aircraft HALO
Directory of Open Access Journals (Sweden)
M. Mech
2014-05-01
Full Text Available An advanced package of microwave remote sensing instrumentation has been developed for the operation on the new German High Altitude LOng range research aircraft (HALO. The HALO Microwave Package, HAMP, consists of two nadir looking instruments: a cloud radar at 36 GHz and a suite of passive microwave radiometers with 26 frequencies in different bands between 22.24 and 183.31 ± 12.5 GHz. We present a description of HAMP's instrumentation together with an illustration of its potential. To demonstrate this potential synthetic measurements for the implemented passive microwave frequencies and the cloud radar based on cloud resolving and radiative transfer model calculations were performed. These illustrate the advantage of HAMP's chosen frequency coverage, which allows for improved detection of hydrometeors both via the emission and scattering of radiation. Regression algorithms compare HAMP retrieval with standard satellite instruments from polar orbiters and show its advantages particularly for the lower atmosphere with a reduced root mean square error by 5 and 15% for temperature and humidity, respectively. HAMP's main advantage is the high spatial resolution of about 1 km which is illustrated by first measurements from test flights. Together these qualities make it an exciting tool for gaining better understanding of cloud processes, testing retrieval algorithms, defining future satellite instrument specifications, and validating platforms after they have been placed in orbit.
Emergent ultra-long-range interactions between active particles in hybrid active-inactive systems
Steimel, Joshua P.; Aragones, Juan L.; Hu, Helen; Qureshi, Naser
2016-04-01
Particle-particle interactions determine the state of a system. Control over the range of such interactions as well as their magnitude has been an active area of research for decades due to the fundamental challenges it poses in science and technology. Very recently, effective interactions between active particles have gathered much attention as they can lead to out-of-equilibrium cooperative states such as flocking. Inspired by nature, where active living cells coexist with lifeless objects and structures, here we study the effective interactions that appear in systems composed of active and passive mixtures of colloids. Our systems are 2D colloidal monolayers composed primarily of passive (inactive) colloids, and a very small fraction of active (spinning) ferromagnetic colloids. We find an emergent ultra-long-range attractive interaction induced by the activity of the spinning particles and mediated by the elasticity of the passive medium. Interestingly, the appearance of such interaction depends on the spinning protocol and has a minimum actuation timescale below which no attraction is observed. Overall, these results clearly show that, in the presence of elastic components, active particles can interact across very long distances without any chemical modification of the environment. Such a mechanism might potentially be important for some biological systems and can be harnessed for newer developments in synthetic active soft materials.
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Huang, Lili; Ishibe-Murakami, Satoko; Patel, Dinshaw J.; Serganov, Alexander (MSKCC)
2011-09-15
Tetrahydrofolate (THF), a biologically active form of the vitamin folate (B{sub 9}), is an essential cofactor in one-carbon transfer reactions. In bacteria, expression of folate-related genes is controlled by feedback modulation in response to specific binding of THF and related compounds to a riboswitch. Here, we present the X-ray structures of the THF-sensing domain from the Eubacterium siraeum riboswitch in the ligand-bound and unbound states. The structure reveals an 'inverted' three-way junctional architecture, most unusual for riboswitches, with the junction located far from the regulatory helix P1 and not directly participating in helix P1 formation. Instead, the three-way junction, stabilized by binding to the ligand, aligns the riboswitch stems for long-range tertiary pseudoknot interactions that contribute to the organization of helix P1 and therefore stipulate the regulatory response of the riboswitch. The pterin moiety of the ligand docks in a semiopen pocket adjacent to the junction, where it forms specific hydrogen bonds with two moderately conserved pyrimidines. The aminobenzoate moiety stacks on a guanine base, whereas the glutamate moiety does not appear to make strong interactions with the RNA. In contrast to other riboswitches, these findings demonstrate that the THF riboswitch uses a limited number of available determinants for ligand recognition. Given that modern antibiotics target folate metabolism, the THF riboswitch structure provides insights on mechanistic aspects of riboswitch function and may help in manipulating THF levels in pathogenic bacteria
Observation of long-range tertiary interactions during ligand binding by the TPP riboswitch aptamer.
Duesterberg, Van K; Fischer-Hwang, Irena T; Perez, Christian F; Hogan, Daniel W; Block, Steven M
2015-12-28
The thiamine pyrophosphate (TPP) riboswitch is a cis-regulatory element in mRNA that modifies gene expression in response to TPP concentration. Its specificity is dependent upon conformational changes that take place within its aptamer domain. Here, the role of tertiary interactions in ligand binding was studied at the single-molecule level by combined force spectroscopy and Förster resonance energy transfer (smFRET), using an optical trap equipped for simultaneous smFRET. The 'Force-FRET' approach directly probes secondary and tertiary structural changes during folding, including events associated with binding. Concurrent transitions observed in smFRET signals and RNA extension revealed differences in helix-arm orientation between two previously-identified ligand-binding states that had been undetectable by spectroscopy alone. Our results show that the weaker binding state is able to bind to TPP, but is unable to form a tertiary docking interaction that completes the binding process. Long-range tertiary interactions stabilize global riboswitch structure and confer increased ligand specificity.
Huang, Lili; Ishibe-Murakami, Satoko; Patel, Dinshaw J; Serganov, Alexander
2011-09-06
Tetrahydrofolate (THF), a biologically active form of the vitamin folate (B(9)), is an essential cofactor in one-carbon transfer reactions. In bacteria, expression of folate-related genes is controlled by feedback modulation in response to specific binding of THF and related compounds to a riboswitch. Here, we present the X-ray structures of the THF-sensing domain from the Eubacterium siraeum riboswitch in the ligand-bound and unbound states. The structure reveals an "inverted" three-way junctional architecture, most unusual for riboswitches, with the junction located far from the regulatory helix P1 and not directly participating in helix P1 formation. Instead, the three-way junction, stabilized by binding to the ligand, aligns the riboswitch stems for long-range tertiary pseudoknot interactions that contribute to the organization of helix P1 and therefore stipulate the regulatory response of the riboswitch. The pterin moiety of the ligand docks in a semiopen pocket adjacent to the junction, where it forms specific hydrogen bonds with two moderately conserved pyrimidines. The aminobenzoate moiety stacks on a guanine base, whereas the glutamate moiety does not appear to make strong interactions with the RNA. In contrast to other riboswitches, these findings demonstrate that the THF riboswitch uses a limited number of available determinants for ligand recognition. Given that modern antibiotics target folate metabolism, the THF riboswitch structure provides insights on mechanistic aspects of riboswitch function and may help in manipulating THF levels in pathogenic bacteria.
Long range dependence in the high frequency USD/INR exchange rate
Kumar, Dilip
2014-02-01
Using high frequency data, this paper examines the long memory property in the unconditional and conditional volatility of the USD/INR exchange rate at different time scales using the Local Whittle (LW), the Exact Local Whittle (ELW) and the FIAPARCH models. Results indicate that the long memory property remains quite stable across different time scales for both unconditional and conditional volatility measures. Results from the non-overlapping moving window approach indicate that the extreme events (such as the subprime crisis and the European debt crisis) resulted in highly persistent behavior of the USD/INR exchange rate and thus lead to market inefficiency. This paper also examines the long memory property in the realized volatility based on different time scale data. Results indicate that the realized volatility measures based on different scales of the high frequency data exhibit a consistent and stable long memory property. However, the realized volatility measures based on daily data exhibit lower degree of long-range dependence. This study has implications for traders and investors (with different trading horizons) and can be helpful in predicting expected future volatility and in designing and implementing trading strategies at different time scales.
Influence of long-range interactions on strategy selection in crowd
Malarz, K; Kulakowski, K
2013-01-01
An order--disorder phase transition is observed for Ising-like systems even for arbitrarily chosen probabilities of spins flips [K. Malarz et al, Int. J. Mod. Phys. C 22, 719 (2011)]. For such athermal dynamics one must define $(z+1)$ spin flips probabilities $w(n)$, where $z$ is a number of the nearest-neighbours for given regular lattice and $n=0,\\cdots,z$ indicates the number of nearest spins with the same value as the considered spin. Recently, such dynamics has been successfully applied for the simulation of a cooperative and competitive strategy selection by pedestrians in crowd [P. Gawro\\'nski et al, Acta Phys. Pol. A 123, 522 (2013)]. For the triangular lattice ($z=6$) and flips probabilities dependence on a single control parameter $x$ chosen as $w(0)=1$, $w(1)=3x$, $w(2)=2x$, $w(3)=x$, $w(4)=x/2$, $w(5)=x/4$, $w(6)=x/6$ the ordered phase (where most of pedestrians adopt the same strategy) vanishes for $x>x_C\\approx 0.429$. In order to introduce long-range interactions between pedestrians the bonds o...
Fast methods for long-range interactions in complex systems. Lecture notes
Energy Technology Data Exchange (ETDEWEB)
Sutmann, Godehard; Gibbon, Paul; Lippert, Thomas (eds.)
2011-10-13
Parallel computing and computer simulations of complex particle systems including charges have an ever increasing impact in a broad range of fields in the physical sciences, e.g. in astrophysics, statistical physics, plasma physics, material sciences, physical chemistry, and biophysics. The present summer school, funded by the German Heraeus-Foundation, took place at the Juelich Supercomputing Centre from 6 - 10 September 2010. The focus was on providing an introduction and overview over different methods, algorithms and new trends for the computational treatment of long-range interactions in particle systems. The Lecture Notes contain an introduction into particle simulation, as well as five different fast methods, i.e. the Fast Multipole Method, Barnes-Hut Tree Method, Multigrid, FFT based methods, and Fast Summation using the non-equidistant FFT. In addition to introducing the methods, efficient parallelization of the methods is presented in detail. This publication was edited at the Juelich Supercomputing Centre (JSC) which is an integral part of the Institute for Advanced Simulation (IAS). The IAS combines the Juelich simulation sciences and the supercomputer facility in one organizational unit. It includes those parts of the scientific institutes at Forschungszentrum Juelich which use simulation on supercomputers as their main research methodology. (orig.)
Coumarin Dyes for Dye-Sensitized Solar Cells - A Long-Range-Corrected Density Functional Study
Wong, Bryan M; 10.1063/1.3025924
2010-01-01
The excited-state properties in a series of coumarin solar cell dyes are investigated with a long-range-corrected (LC) functional which asymptotically incorporates Hartree-Fock exchange. Using time-dependent density functional theory (TDDFT), we calculate excitation energies, oscillator strengths, and excited-state dipole moments in each of the dyes as a function of the range-separation paramenter, mu. To investigate the acceptable range of mu and assess the quality of the LC-TDDFT formalism, an extensive comparison is made between LC-BLYP excitation energies and approximate coupled cluster singles and doubles (CC2) calculations. When using a properly-optimized value of mu, we find that the LC technique provides a consistent picture of charge-transfer excitations as a function of molecular size. In contrast, we find that the widely-used B3LYP hybrid functional severely overestimates excited-state dipole moments and underestimates vertical excitations energies, especially for larger dye molecules. The results ...
Feature Optimization for Long-Range Visual Homing in Changing Environments
Directory of Open Access Journals (Sweden)
Qidan Zhu
2014-02-01
Full Text Available This paper introduces a feature optimization method for robot long-range feature-based visual homing in changing environments. To cope with the changing environmental appearance, the optimization procedure is introduced to distinguish the most relevant features for feature-based visual homing, including the spatial distribution, selection and updating. In the previous research on feature-based visual homing, less effort has been spent on the way to improve the feature distribution to get uniformly distributed features, which are closely related to homing performance. This paper presents a modified feature extraction algorithm to decrease the influence of anisotropic feature distribution. In addition, the feature selection and updating mechanisms, which have hardly drawn any attention in the domain of feature-based visual homing, are crucial in improving homing accuracy and in maintaining the representation of changing environments. To verify the feasibility of the proposal, several comprehensive evaluations are conducted. The results indicate that the feature optimization method can find optimal feature sets for feature-based visual homing, and adapt the appearance representation to the changing environments as well.
Application of long-range order to predict unfolding rates of two-state proteins.
Harihar, B; Selvaraj, S
2011-03-01
Predicting the experimental unfolding rates of two-state proteins and models describing the unfolding rates of these proteins is quite limited because of the complexity present in the unfolding mechanism and the lack of experimental unfolding data compared with folding data. In this work, 25 two-state proteins characterized by Maxwell et al. (Protein Sci 2005;14:602–616) using a consensus set of experimental conditions were taken, and the parameter long-range order (LRO) derived from their three-dimensional structures were related with their experimental unfolding rates ln(k(u)). From the total data set of 30 proteins used by Maxwell et al. (Protein Sci 2005;14:602–616), five slow-unfolding proteins with very low unfolding rates were considered to be outliers and were not included in our data set. Except all beta structural class, LRO of both the all-alpha and mixed-class proteins showed a strong inverse correlation of r = -0.99 and -0.88, respectively, with experimental ln(k(u)). LRO shows a correlation of -0.62 with experimental ln(k(u)) for all-beta proteins. For predicting the unfolding rates, a simple statistical method has been used and linear regression equations were developed for individual structural classes of proteins using LRO, and the results obtained showed a better agreement with experimental results.
Long-range memory in millennium-long ESM and AOGCM experiments
Directory of Open Access Journals (Sweden)
L. Østvand
2014-03-01
Full Text Available Northern Hemisphere (NH temperature records from a reconstruction and a number of millennium-long climate model experiments are investigated for long-range memory (LRM. The models are two Earth system models and two atmospheric-ocean general circulation models. The periodogram, detrended fluctuation analysis and wavelet variance analysis are applied to examine scaling properties and to estimate a scaling exponent of the temperature records. A simple linear model for the climate response to external forcing is also applied to the reconstruction and the forced climate model runs, and then compared to unforced control runs to extract the LRM generated by internal dynamics of the climate system. With one exception the climate models show strong persistent scaling with power spectral densities of the form S(f ~ f−β with 0.8 < β < 1 on time scales from years to several centuries. This is somewhat stronger persistence than found in the reconstruction (β ≈ 0.7. The exception is the HadCM3 model, which exhibits β ≈ 0.6. We find no indication that LRM found in these model runs are induced by external forcing, which suggests that LRM on sub-decadal to century time scales in NH mean temperatures is a property of the internal dynamics of the climate system. Temperature records for a local site, Reykjanes Ridge, are also studied, showing that strong persistence is found also for local ocean temperature.
Long-Range Ruthenium-Amine Electronic Communication through the para-Oligophenylene Wire
Shen, Jun-Jian; Zhong, Yu-Wu
2015-09-01
The studies of long-range electronic communication are hampered by solubility and potential-splitting issues. A “hybridized redox-asymmetry” method using a combination of organic and inorganic redox species is proposed and exemplified to overcome these two issues. Complexes 1(PF6)-6(PF6) (from short to long in length) with the organic redox-active amine and inorganic cyclometalated ruthenium termini bridged by the para-oligophenylene wire have been prepared. Complex 6 has the longest Ru-amine geometrical distance of 27.85 Å. Complexes 3(PF6) and 4(PF6) show lamellar crystal packing on the basis of a head-to-tail anti-parallelly aligned dimeric structure. Two redox waves are observed for all complexes in the potential region between +0.2 and +0.9 V vs Ag/AgCl. The electrochemical potential splitting is 410, 220, 143, 112, 107, and 105 mV for 1(PF6) through 6(PF6), respectively. Ruthenium (+2) to aminium (N•+) charge transfer transitions have been identified for the odd-electron compounds 12+-62+ by spectroelectrochemical measurements. The electronic communication between amine and ruthenium decreases exponentially with a decay slope of -0.137 Å-1. DFT calculations have been performed to complement these experimental results.
Genetic analysis of the PKHD1 gene with long-rang PCR sequencing.
Tong, Yong-Qing; Liu, Bei; Fu, Chao-Hong; Zheng, Hong-Yun; Gu, Jian; Liu, Hang; Luo, Hong-Bo; Li, Yan
2016-10-01
PKHD1 gene mutations are found responsible for autosomal recessive polycystic kidney disease (ARPKD). However, it is inconvenient to detect the mutations by common polymerase chain reaction (PCR) because the open reading frame of PKHD1 is very long. Recently, long-range (LR) PCR is demonstrated to be a more sensitive mutation screening method for PKHD1 by directly sequencing. In this study, the entire PKHD1 coding region was amplified by 29 reactions to avoid the specific PCR amplification of individual exons, which generated the size of 1 to 7 kb products by LR PCR. This method was compared to the screening method with standard direct sequencing of each individual exon of the gene by a reference laboratory in 15 patients with ARPKD. The results showed that a total of 37 genetic changes were detected with LR PCR sequencing, which included 33 variations identified by the reference laboratory with standard direct sequencing. LR PCR sequencing had 100% sensitivity, 96% specificity, and 97.0% accuracy, which were higher than those with standard direct sequencing method. In conclusion, LR PCR sequencing is a reliable method with high sensitivity, specificity and accuracy for detecting genetic variations. It also has more intronic coverage and lower cost, and is an applicable clinical method for complex genetic analyses.
Exploring the dynamics of phase separation in colloid-polymer mixtures with long range attraction.
Sabin, Juan; Bailey, Arthur E; Frisken, Barbara J
2016-06-28
We have studied the kinetics of phase separation and gel formation in a low-dispersity colloid - non-adsorbing polymer system with long range attraction using small-angle light scattering. This system exhibits two-phase and three-phase coexistence of gas, liquid and crystal phases when the strength of attraction is between 2 and 4kBT and gel phases when the strength of attraction is increased. For those samples that undergo macroscopic phase separation, whether to gas-crystal, gas-liquid or gas-liquid-crystal coexistence, we observe dynamic scaling of the structure factor and growth of a characteristic length scale that behaves as expected for phase separation in fluids. In samples that gel, the power law associated with the growth of the dominant length scale is not equal to 1/3, but appears to depend mainly on the strength of attraction, decreasing from 1/3 for samples near the coexistence region to 1/27 at 8kBT, over a wide range of colloid and polymer concentrations.
Investigating long-range correlation properties in EEG during complex cognitive tasks
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Karkare, Siddharth [Department of Electrical Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Saha, Goutam [Department of Electronics and Electrical Communication Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Bhattacharya, Joydeep [Department of Psychology, Goldsmiths College, University of London, New Cross, London SE14 6NW (United Kingdom); Commission for Scientific Visualization, Austrian Academy of Sciences, Vienna A1220 (Austria)], E-mail: j.bhattacharya@gold.ac.uk
2009-11-30
Previous work shows the presence of scale invariance and long-range correlations in ongoing and spontaneous activity of large scale brain responses (i.e. EEG), and such scaling behavior can also be modulated by simple sensory stimulus. However, little is known whether such alteration but not destruction in scaling properties also occurs during complex cognitive processing and if neuroplasticity plays any role in mediating such changes. In this study, we addressed these issues by investigating scaling properties of multivariate EEG signals obtained from two broad groups - artists and non-artists - while they performed complex tasks of perception and mental imagery of visual art objects. We found that brain regions showing increased correlation properties from rest were similar for both tasks, suggesting that brain networks responsible for visual perception are reactivated for mental imagery. Further, we observed that the two groups could be differentiated by scaling exponents and an artificial neural network based classifier achieved a classification efficiency of over 80%. These results altogether suggest that specific complex cognitive task demands and task-specific expertise can modify the temporal scale-free dynamics of brain responses.
Long-range correction for tight-binding TD-DFT
Humeniuk, Alexander
2015-01-01
We present two improvements to the tight-binding approximation of time-dependent density functional theory (TD-DFTB): Firstly, we add an exact Hartree-Fock exchange term, which is switched on at large distances, to the ground state Hamiltonian and similarly to the coupling matrix that enters the linear response equations for the calculation excited electronic states. We show that the excitation energies of charge transfer states are improved relative to the standard approach without the long-range correction by testing the method on a set of molecules from the database in J. Chem. Phys. (2008),128,044118. that are known to exhibit problematic charge transfer states. The degree of spatial overlap between occupied and virtual orbitals indicates where TD-DFTB and lc-TD-DFTB can be expected to produce large errors. Secondly, we improve the calculation of oscillator strengths. The transition dipoles are obtained from Slater Koster files for the dipole matrix elements between valence orbitals. In particular excitat...
Long-range Ising model for credit portfolios with heterogeneous credit exposures
Kato, Kensuke
2016-11-01
We propose the finite-size long-range Ising model as a model for heterogeneous credit portfolios held by a financial institution in the view of econophysics. The model expresses the heterogeneity of the default probability and the default correlation by dividing a credit portfolio into multiple sectors characterized by credit rating and industry. The model also expresses the heterogeneity of the credit exposure, which is difficult to evaluate analytically, by applying the replica exchange Monte Carlo method to numerically calculate the loss distribution. To analyze the characteristics of the loss distribution for credit portfolios with heterogeneous credit exposures, we apply this model to various credit portfolios and evaluate credit risk. As a result, we show that the tail of the loss distribution calculated by this model has characteristics that are different from the tail of the loss distribution of the standard models used in credit risk modeling. We also show that there is a possibility of different evaluations of credit risk according to the pattern of heterogeneity.
DNA and IκBα both induce long range conformational changes in NFκB.
Ramsey, Kristen M; Dembinski, Holly E; Chen, Wei; Ricci, Clarisse G; Komives, Elizabeth A
2017-02-26
We recently discovered that IκBα enhances the rate of release of NFκB from DNA target sites in a process we have termed molecular stripping. Coarse-grained molecular dynamics simulations of the stripping pathway revealed two mechanisms for the enhanced release rate; the negatively charged PEST region of IκBα electrostatically repels the DNA, and binding of IκBα appears to twist the NFκB heterodimer so that DNA can no longer bind. Here we report amide hydrogen/deuterium exchange data that reveals long-range allosteric changes in the NFκB (RelA-p50) heterodimer induced by DNA or IκBα binding. The data suggest that the two immunoglobulin-like subdomains of each Rel-homology region, which are connected by a flexible linker in the heterodimer, communicate in such a way that when DNA binds to the N-terminal DNA binding domains, the nuclear localization signal becomes more highly exchanging. Conversely, when IκBα binds to the dimerization domains, amide exchange throughout the DNA binding domains is decreased as if the entire domain is becoming globally stabilized. The results help understand how the subtle mechanism of molecular stripping actually occurs.
Upper and lower critical decay exponents of Ising ferromagnets with long-range interaction
Horita, Toshiki; Suwa, Hidemaro; Todo, Synge
2017-01-01
We investigate the universality class of the finite-temperature phase transition of the two-dimensional Ising model with the algebraically decaying ferromagnetic long-range interaction, Ji j=|r⃗i-r⃗j| -(d +σ ) , where d (=2) is the dimension of the system and σ is the decay exponent, by means of the order-N cluster-algorithm Monte Carlo method. In particular, we focus on the upper and lower critical decay exponents, the boundaries between the mean-field-universality, intermediate, and short-range-universality regimes. At the critical decay exponents, it is found that the standard Binder ratio of magnetization at the critical temperature exhibits extremely slow convergence as a function of the system size. We propose more effective physical quantities, namely the combined Binder ratio and the self-combined Binder ratio, both of which cancel the leading finite-size corrections of the conventional Binder ratio. Utilizing these techniques, we clearly demonstrate that in two dimensions, the lower and upper critical decay exponents are σ =1 and 7/4, respectively, contrary to the recent Monte Carlo and renormalization-group studies [M. Picco, arXiv:1207.1018; T. Blanchard et al., Europhys. Lett. 101, 56003 (2013) 10.1209/0295-5075/101/56003].
Estimating long-range dependence in time series: an evaluation of estimators implemented in R.
Stroe-Kunold, Esther; Stadnytska, Tetiana; Werner, Joachim; Braun, Simone
2009-08-01
Recent studies have shown that many physiological and behavioral processes can be characterized by long-range correlations. The Hurst exponent H of fractal analysis and the fractional-differencing parameter d of the ARFIMA methodology are useful for capturing serial correlations. In this study, we report on different estimators of H and d implemented in R, a popular and freely available software package. By means of Monte Carlo simulations, we analyzed the performance of (1) the Geweke-Porter-Hudak estimator, (2) the approximate maximum likelihood algorithm, (3) the smoothed periodogram approach, (4) the Whittle estimator, (5) rescaled range analysis, (6) a modified periodogram, (7) Higuchi's method, and (8) detrended fluctuation analysis. The findings-confined to ARFIMA (0, d, 0) models and fractional Gaussian noise-identify the best estimators for persistent and antipersistent series. Two examples combining these results with the step-by-step procedure proposed by Delignières et al. (2006) demonstrate how this evaluation can be used as a guideline in a typical research situation.
Long-range correlated dynamics in ultra-thin molecular glass films
Zhang, Yue; Glor, Ethan C.; Li, Mu; Liu, Tianyi; Wahid, Kareem; Zhang, William; Riggleman, Robert A.; Fakhraai, Zahra
2016-09-01
It has been previously shown that the free surface of molecular glasses has enhanced surface diffusion compared to the bulk. However, the degree by which the glass dynamics are affected by the free surface remains unexplored. Here, we measure enhanced dynamics in ultra-thin molecular glass films as a function of film thickness. We demonstrate that these films exhibit a sharp transition from glassy solid to liquid-like behavior when the thickness is reduced below 30 nm. This liquid-like behavior persists even at temperatures well below the glass transition temperature, Tg. The enhanced dynamics in these films can produce large scale morphological features during physical vapor deposition and lead to a dewetting instability in films held at temperatures as low as Tg - 35 K. The effective viscosity of these films are measured by monitoring the dewetting kinetics. These measurements combined with cooling-rate dependent Tg measurements show that the apparent activation barrier for rearrangement decreases sharply in films thinner than 30 nm. This sharp transition in the dynamics suggests that long-range correlated dynamics exists in these films such that the enhancement induced by the free surface can strongly affect the dynamics of the film over a length scale that is ten times larger than the size of the molecules.
Dynamic Long-Range Chromatin Interaction Controls Expression of IL-21 in CD4+ T Cells.
Park, Joo-Hong; Choi, Yeeun; Song, Min-Ji; Park, Keunhee; Lee, Jong-Joo; Kim, Hyoung-Pyo
2016-05-15
IL-21, a pleiotropic cytokine strongly linked with autoimmunity and inflammation, regulates diverse immune responses. IL-21 can be potently induced in CD4(+) T cells by IL-6; however, very little is known about the mechanisms underlying the transcriptional regulation of the Il21 gene at the chromatin level. In this study, we demonstrated that a conserved noncoding sequence located 49 kb upstream of the Il21 gene contains an enhancer element that can upregulate Il21 gene expression in a STAT3- and NFAT-dependent manner. Additionally, we identified enhancer-blocking insulator elements in the Il21 locus, which constitutively bind CTCF and cohesin. In naive CD4(+) T cells, these upstream and downstream CTCF binding sites interact with each other to make a DNA loop; however, the Il21 promoter does not interact with any cis-elements in the Il21 locus. In contrast, stimulation of CD4(+) T cells with IL-6 leads to recruitment of STAT3 to the promoter and novel distal enhancer region. This induces dynamic changes in chromatin configuration, bringing the promoter and the regulatory elements in close spatial proximity. The long-range interaction between the promoter and distal enhancer region was dependent on IL-6/STAT3 signaling pathway but was disrupted in regulatory T cells, where IL-21 expression was repressed. Thus, our work uncovers a novel topological chromatin framework underlying proper transcriptional regulation of the Il21 gene.
Loss of long-range magnetic order in a nanoparticle assembly due to random anisotropy
Energy Technology Data Exchange (ETDEWEB)
Binns, C [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Howes, P B [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Baker, S H [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Marchetto, H [Diamond Light Source Ltd, Harwell Science and Innovation Campus, Diamond House, Chilton, Didcot, Oxfordshire OX11 0DE (United Kingdom); Potenza, A [Diamond Light Source Ltd, Harwell Science and Innovation Campus, Diamond House, Chilton, Didcot, Oxfordshire OX11 0DE (United Kingdom); Steadman, P [Diamond Light Source Ltd, Harwell Science and Innovation Campus, Diamond House, Chilton, Didcot, Oxfordshire OX11 0DE (United Kingdom); Dhesi, S S [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Roy, M [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Everard, M J [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Rushforth, A [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)
2008-02-06
We have used soft x-ray photoemission electron microscopy (XPEEM) combined with x-ray magnetic circular dichroism (XMCD) and DC SQUID (superconducting quantum interference device) magnetometry to probe the magnetic ground state in Fe thin films produced by depositing size-selected gas-phase Fe nanoparticles with a diameter of 1.7 nm ({approx}200 atoms) onto Si substrates. The depositions were carried out in ultrahigh vacuum conditions and thicknesses of the deposited film in the range 5-50 nm were studied. The magnetometry data are consistent with the film forming a correlated super-spin glass with a magnetic correlation length {approx}5 nm. The XPEEM magnetic maps from the cluster-assembled films were compared to those for a conventional thin Fe film with a thickness of 20 nm produced by a molecular beam epitaxy (MBE) source. Whereas a normal magnetic domain structure is observed in the conventional MBE thin film, no domain structure could be observed in any of the nanoparticle films down to the resolution limit of the XMCD based XPEEM (100 nm) confirming the ground state indicated by the magnetometry measurements. This observation is consistent with the theoretical prediction that an arbitrarily weak random anisotropy field will destroy long-range magnetic order.
Pairing in high-density neutron matter including short- and long-range correlations
Ding, D; Dickhoff, W H; Dussan, H; Polls, A; Witte, S J
2015-01-01
The influence of short-range correlations (SRC) on the spectral distribution of neutrons is incorporated in the solution of the gap equation for the ${}^3P_2-{}^3F_2$ coupled channel in pure neutron matter at high density. This effect is studied for three different realistic interactions. The gap in this channel is strongly suppressed by these correlations but does not vanish. For a consistent treatment we also include for the first time the effect of long-range correlations (LRC) by incorporating polarization terms in addition to the bare interaction. This allows the neutrons to exchange density and spin fluctuations governed by the strength of Landau parameters with values that are consistent with the available literature. While these LRC have an antiscreening tendency, they only slightly increase the gap in the ${}^3P_2-{}^3F_2$ coupled channel for all three realistic interactions as long as SRC are included. All three interactions generate maximum gaps around 0.1 to 0.2 MeV at most with a small dependence...
Long-Range Trilobite-like Cs Molecules in a Crossed 1064 nm Dipole Trap
Tallant, Jonathan; Booth, Donald; Marcassa, Luis; Marangoni, Bruno; Shaffer, James
2011-05-01
In the past, our group has observed long-range Rydberg atom- Rydberg atom molecules created within a MOT. The density required to observe such molecules can be relatively low, 1010 cm-3 because the bound states exist at internuclear separations between ~ 3 μ m and ~ 9 μ m. The increase in density to ~1013 cm-3 in a crossed dipole trap allows for new types of molecule formation which are inefficient in lower density traps, like the MOT. In particular, new bonding mechanisms may arise from the low-energy scattering of a Rydberg atom electron (with negative scattering length) from a ground state atom, so called trilobite and trilobite-like molecules. We present data on the spectroscopic identification of Cs n2S1 / 2 + 62S1 / 2 trilobite-like molecules. Progress on resolving the vibrational structure of both singlet and triplet species will be presented. We acknowledge funding from ARO (W911-NF-08-1-0257), NSF (PHY- 0855324) and NSF (OISE-0756321).
DROUGHT FORECASTING BASED ON MACHINE LEARNING OF REMOTE SENSING AND LONG-RANGE FORECAST DATA
Directory of Open Access Journals (Sweden)
J. Rhee
2016-06-01
Full Text Available The reduction of drought impacts may be achieved through sustainable drought management and proactive measures against drought disaster. Accurate and timely provision of drought information is essential. In this study, drought forecasting models to provide high-resolution drought information based on drought indicators for ungauged areas were developed. The developed models predict drought indices of the 6-month Standardized Precipitation Index (SPI6 and the 6-month Standardized Precipitation Evapotranspiration Index (SPEI6. An interpolation method based on multiquadric spline interpolation method as well as three machine learning models were tested. Three machine learning models of Decision Tree, Random Forest, and Extremely Randomized Trees were tested to enhance the provision of drought initial conditions based on remote sensing data, since initial conditions is one of the most important factors for drought forecasting. Machine learning-based methods performed better than interpolation methods for both classification and regression, and the methods using climatology data outperformed the methods using long-range forecast. The model based on climatological data and the machine learning method outperformed overall.
Cluster formation in fluids with competing short-range and long-range interactions
Energy Technology Data Exchange (ETDEWEB)
Sweatman, Martin B., E-mail: martin.sweatman@ed.ac.uk; Fartaria, Rui [Institute of Materials and Processes, School of Engineering, University of Edinburgh, Edinburgh EH9 3JL (United Kingdom); Lue, Leo [Department of Chemical and Process Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom)
2014-03-28
We investigate the low density behaviour of fluids that interact through a short-ranged attraction together with a long-ranged repulsion (SALR potential) by developing a molecular thermodynamic model. The SALR potential is a model of effective solute interactions where the solvent degrees of freedom are integrated-out. For this system, we find that clusters form for a range of interaction parameters where attractive and repulsive interactions nearly balance, similar to micelle formation in aqueous surfactant solutions. We focus on systems for which equilibrium behaviour and liquid-like clusters (i.e., droplets) are expected, and find in addition a novel coexistence between a low density cluster phase and a high density cluster phase within a very narrow range of parameters. Moreover, a simple formula for the average cluster size is developed. Based on this formula, we propose a non-classical crystal nucleation pathway whereby macroscopic crystals are formed via crystal nucleation within microscopic precursor droplets. We also perform large-scale Monte Carlo simulations, which demonstrate that the cluster fluid phase is thermodynamically stable for this system.
Long-range correlations and burstiness in written texts: Universal and language-specific aspects
Constantoudis, Vassilios; Kalimeri, Maria; Diakonos, Fotis; Karamanos, Konstantinos; Papadimitriou, Constantinos; Chatzigeorgiou, Manolis; Papageorgiou, Harris
2016-08-01
Recently, methods from the statistical physics of complex systems have been applied successfully to identify universal features in the long-range correlations (LRCs) of written texts. However, in real texts, these universal features are being intermingled with language-specific influences. This paper aims at the characterization and further understanding of the interplay between universal and language-specific effects on the LRCs in texts. To this end, we apply the language-sensitive mapping of written texts to word-length series (wls) and analyse large parallel (of same content) corpora from 10 languages classified to four families (Romanic, Germanic, Greek and Uralic). The autocorrelation functions of the wls reveal tiny but persistent LRCs decaying at large scales following a power-law with a language-independent exponent ˜0.60-0.65. The impact of language is displayed in the amplitude of correlations where a relative standard deviation >40% among the analyzed languages is observed. The classification to language families seems to play a significant role since, the Finnish and Germanic languages exhibit more correlations than the Greek and Roman families. To reveal the origins of the LRCs, we focus on the long words and perform burst and correlation analysis in their positions along the corpora. We find that the universal features are linked more to the correlations of the inter-long word distances while the language-specific aspects are related more to their distributions.
The ground state of long-range Schrodinger equations and static $q\\bar{q}$ potential
Beccaria, Matteo; Pallara, Diego
2016-01-01
Motivated by the recent results in arXiv:1601.05679 about the quark-antiquark potential in $\\mathcal N=4$ SYM, we reconsider the problem of computing the asymptotic weak-coupling expansion of the ground state energy of a certain class of 1d Schr\\"odinger operators $-\\frac{d^{2}}{dx^{2}}+\\lambda\\,V(x)$ with long-range potential $V(x)$. In particular, we consider even potentials obeying $\\int_{\\mathbb R}dx\\, V(x)<0$ with large $x$ asymptotics $V\\sim -a/x^{2}-b/x^{3}+\\cdots$. The associated Schr\\"odinger operator is known to admit a bound state for $\\lambda\\to 0^{+}$, but the binding energy is rigorously non-analytic at $\\lambda=0$. Its asymptotic expansion starts at order $\\mathcal O(\\lambda)$, but contains higher corrections $\\lambda^{n}\\,\\log^{m}\\lambda$ with all $0\\le m\\le n-1$ and standard Rayleigh-Schr\\"odinger perturbation theory fails order by order in $\\lambda$. We discuss various analytical tools to tame this problem and provide the general expansion of the binding energy at $\\mathcal O(\\lambda^{3})...
Use of long-range repetitive element polymorphism-PCR to differentiate Bacillus anthracis strains.
Brumlik, M J; Szymajda, U; Zakowska, D; Liang, X; Redkar, R J; Patra, G; Del Vecchio, V G
2001-07-01
The genome of Bacillus anthracis is extremely monomorphic, and thus individual strains have often proven to be recalcitrant to differentiation at the molecular level. Long-range repetitive element polymorphism-PCR (LR REP-PCR) was used to differentiate various B. anthracis strains. A single PCR primer derived from a repetitive DNA element was able to amplify variable segments of a bacterial genome as large as 10 kb. We were able to characterize five genetically distinct groups by examining 105 B. anthracis strains of diverse geographical origins. All B. anthracis strains produced fingerprints comprising seven to eight bands, referred to as "skeleton" bands, while one to three "diagnostic" bands differentiated between B. anthracis strains. LR REP-PCR fingerprints of B. anthracis strains showed very little in common with those of other closely related species such as B. cereus, B. thuringiensis, and B. mycoides, suggesting relative heterogeneity among the non-B. anthracis strains. Fingerprints from transitional non-B. anthracis strains, which possessed the B. anthracis chromosomal marker Ba813, scarcely resembled those observed for any of the five distinct B. anthracis groups that we have identified. The LR REP-PCR method described in this report provides a simple means of differentiating B. anthracis strains.
Short- and long-range magnetic order in LaMnAsO
McGuire, Michael A.; Garlea, V. Ovidiu
2016-02-01
The magnetic properties of the layered oxypnictide LaMnAsO have been revisited using neutron scattering and magnetization measurements. The present measurements identify the Néel temperature TN=360 (1 ) K. Below TN the critical exponent describing the magnetic order parameter is β =0.33 -0.35 , consistent with a three-dimensional Heisenberg model. Above this temperature, diffuse magnetic scattering indicative of short-range magnetic order is observed, and this scattering persists up to TSRO=650 (10 ) K. The magnetic susceptibility shows a weak anomaly at TSRO and no anomaly at TN. Analysis of the diffuse scattering data using a reverse Monte Carlo algorithm indicates that above TN nearly two-dimensional, short-range magnetic order is present with a correlation length of 9.3(3) Å within the Mn layers at 400 K. The inelastic scattering data reveal a spin gap of 3.5 meV in the long-range ordered state, and strong, low-energy (quasielastic) magnetic excitations emerging in the short-range ordered state. Comparison with other related compounds correlates the distortion of the Mn coordination tetrahedra to the sign of the magnetic exchange along the layer-stacking direction, and suggests that short-range order above TN is a common feature in the magnetic behavior of layered Mn-based pnictides and oxypnictides.
Probing long-range leptonic forces with solar and reactor neutrinos
González-Garciá, M C; Massó, E; Zukanovich-Funchal, R
2007-01-01
In this work we study the phenomenological consequences of the existence of long-range forces coupled to lepton flavour numbers in solar neutrino oscillations. We study electronic forces mediated by scalar, vector or tensor neutral bosons and analyze their effect on the propagation of solar neutrinos as a function of the force strength and range. Under the assumption of one mass scale dominance, we perform a global analysis of solar and KamLAND neutrino data which depends on the two standard oscillation parameters, \\Delta m^2_{21} and \\tan^2\\theta_{12}, the force coupling constant, its range and, for the case of scalar-mediated interactions, on the neutrino mass scale as well. We find that, generically, the inclusion of the new interaction does not lead to a very statistically significant improvement on the description of the data in the most favored MSW LMA (or LMA-I) region. It does, however, substantially improve the fit in the high-\\Delta m^2 LMA (or LMA-II) region which can be allowed for vector and scal...
Directory of Open Access Journals (Sweden)
Umesh Kulshrestha
2014-01-01
Full Text Available This paper presents a review of airmass trajectories and their role in air pollution transport. It describes the concept, history, and basic calculation of air trajectories citing various trajectory models used worldwide. It highlights various areas of trajectory applications and errors associated with trajectory calculations. South Asian region receives airmasses from Europe, Middle East, Africa, and Indian Ocean, and so forth, depending upon the season. These airmasses are responsible for export and import of pollutants depositing in nearby states. Trajectory analysis revealed that soil is contributed by the dust storms coming from Oman through Gulf and Iran, while most of black carbon (BC sources are located in India. A detailed review of trajectories associated with wet deposition events indicated that airmasses coming from Europe and Middle East carry high concentration of acidic pollutants which are deposited in Himalayan ranges. Similarly, trajectory analysis revealed that acidic pollutants from continental anthropogenic sources are transported to an ecosensitive site in Western Ghats in India and the outward fluxes of anthropogenic activities of Indo-Gangetic region are transported towards Bay of Bengal. Hence, transboundary and long range transport of pollutants are very important issues in South Asia which need immediate attention of scientists and policy makers.
Long-Range Memory in Literary Texts: On the Universal Clustering of the Rare Words.
Tanaka-Ishii, Kumiko; Bunde, Armin
2016-01-01
A fundamental problem in linguistics is how literary texts can be quantified mathematically. It is well known that the frequency of a (rare) word in a text is roughly inverse proportional to its rank (Zipf's law). Here we address the complementary question, if also the rhythm of the text, characterized by the arrangement of the rare words in the text, can be quantified mathematically in a similar basic way. To this end, we consider representative classic single-authored texts from England/Ireland, France, Germany, China, and Japan. In each text, we classify each word by its rank. We focus on the rare words with ranks above some threshold Q and study the lengths of the (return) intervals between them. We find that for all texts considered, the probability SQ(r) that the length of an interval exceeds r, follows a perfect Weibull-function, SQ(r) = exp(-b(β)rβ), with β around 0.7. The return intervals themselves are arranged in a long-range correlated self-similar fashion, where the autocorrelation function CQ(s) of the intervals follows a power law, CQ(s) ∼ s-γ, with an exponent γ between 0.14 and 0.48. We show that these features lead to a pronounced clustering of the rare words in the text.
The triton with long-range chiral N3LO three nucleon forces
Skibinski, R; Topolnicki, K; Witala, H; Epelbaum, E; Gloeckle, W; Krebs, H; Nogga, A; Kamada, H
2011-01-01
Long-range contributions to the three-nucleon force that have been recently worked out in chiral effective field theory at next-to-next-to-next-to-leading order are for the first time included in the triton and the doublet nucleon-deuteron scattering length calculations. The strengths of the two short-range terms available at this order in the chiral expansion are determined from the triton binding energy and the neutron-deuteron doublet scattering length. The structure of the resulting three-nucleon force is explored and effects for the two-nucleon correlation function in the triton are investigated. Expectation values of the individual contributions to the three-nucleon force in the triton are found to be in the range from a few 100 keV to about 1 MeV. Our study demonstrates that the very complicated operator structure of the novel chiral three-nucleon forces can be successively implemented in three-nucleon Faddeev calculations.
The future of pathology. Council on Long Range Planning and Development.
1987-07-17
The American Medical Association Council on Long Range Planning and Development has identified trends in the environment of medicine and has assessed their likely implications for the pathology specialty. Competition and economic pressures focused on the hospital setting are likely to continue to affect the choice of delivery site for pathology practice. During the past decade, the pathology specialty has been subject to extensive regulation, placing a new focus on the role of the laboratory within the hospital and generating new ventures for the provision of pathology services. A continuing challenge to the specialty is management innovation and adaptation in the face of regulatory restrictions and cost-containment experiments. The significant forces for change affecting the demand for services and the shape of future provision of pathology services include rapid advances in technology and scientific knowledge, funding for biomedical research, training for research pathologists, demographic trends in the population, and medical liability trends. Finally, with renewed emphasis on quality of care in the health professions, the pathology specialty has the potential to make substantial contributions to the quality and art of medical practice and is likely to remain at the center of efforts to refine methods of quality assessment and implementation.
Long-range interactions between excited helium and alkali-metal atoms
Zhang, J.-Y.
2012-12-03
The dispersion coefficients for the long-range interaction of the first four excited states of He, i.e., He(2 1,3S) and He(2 1,3P), with the low-lying states of the alkali-metal atoms Li, Na, K, and Rb are calculated by summing over the reduced matrix elements of the multipole transition operators. For the interaction between He and Li the uncertainty of the calculations is 0.1–0.5%. For interactions with other alkali-metal atoms the uncertainty is 1–3% in the coefficient C5, 1–5% in the coefficient C6, and 1–10% in the coefficients C8 and C10. The dispersion coefficients Cn for the interaction of He(2 1,3S) and He(2 1,3P) with the ground-state alkali-metal atoms and for the interaction of He(2 1,3S) with the alkali-metal atoms in their first 2P states are presented in this Brief Report. The coefficients for other pairs of atomic states are listed in the Supplemental Material.
Numerical simulation of base flow of a long range flight vehicle
Saha, S.; Rathod, S.; Chandra Murty, M. S. R.; Sinha, P. K.; Chakraborty, Debasis
2012-05-01
Numerical exploration of base flow of a long range flight vehicle is presented for different flight conditions. Three dimensional Navier-Stokes equations are solved along with k-ɛ turbulence model using commercial CFD software. Simulation captured all essential flow features including flow separation at base shoulder, shear layer formation at the jet boundary, recirculation at the base region etc. With the increase in altitude, the plume of the rocket exhaust is seen to bulge more and more and caused more intense free stream and rocket plume interaction leading to higher gas temperature in the base cavity. The flow field in the base cavity is investigated in more detail, which is found to be fairly uniform at different instant of time. Presence of the heat shield is seen to reduce the hot gas entry to the cavity region due to different recirculation pattern in the base region. Computed temperature history obtained from conjugate heat transfer analysis is found to compare very well with flight measured data.
Long-range memory and non-Markov statistical effects in human sensorimotor coordination
M. Yulmetyev, Renat; Emelyanova, Natalya; Hänggi, Peter; Gafarov, Fail; Prokhorov, Alexander
2002-12-01
In this paper, the non-Markov statistical processes and long-range memory effects in human sensorimotor coordination are investigated. The theoretical basis of this study is the statistical theory of non-stationary discrete non-Markov processes in complex systems (Phys. Rev. E 62, 6178 (2000)). The human sensorimotor coordination was experimentally studied by means of standard dynamical tapping test on the group of 32 young peoples with tap numbers up to 400. This test was carried out separately for the right and the left hand according to the degree of domination of each brain hemisphere. The numerical analysis of the experimental results was made with the help of power spectra of the initial time correlation function, the memory functions of low orders and the first three points of the statistical spectrum of non-Markovity parameter. Our observations demonstrate, that with the regard to results of the standard dynamic tapping-test it is possible to divide all examinees into five different dynamic types. We have introduced the conflict coefficient to estimate quantitatively the order-disorder effects underlying life systems. The last one reflects the existence of disbalance between the nervous and the motor human coordination. The suggested classification of the neurophysiological activity represents the dynamic generalization of the well-known neuropsychological types and provides the new approach in a modern neuropsychology.
Institute of Scientific and Technical Information of China (English)
Chen Yu-Dong; Li Li; Zhang Yi; Hu Jian-Ming
2009-01-01
In the study of complex networks(systems),the scaling phenomenon of flow fluctuations rears to a certain power law between the mean flux(activity)(Fi)of the i-th node and its variance σi as σi ∝((Fi)α.Such scaling laws are found to be prevalent both in natural and man-made network systems,but the understanding of their origins still remains limited.This paper proposes a non-stationary Poisson process model to give an analytical explanation of the non-universal scaling phenomenon:the exponent α varies between 1/2 and 1 depending on the size of sampling time window and the relative strength of the external/internal driven forces of the systems.The crossover behaviour and the relation of fluctuation scaling with pseudo long range dependence are also accounted for by the model.Numerical experiments show that the proposed model can recover the multi-scaling phenomenon.