WorldWideScience

Sample records for binary theta muscae

  1. Using the fungus Entomophthora muscae (chon Fresenius to eliminate some larval roles of Musca domestica

    Directory of Open Access Journals (Sweden)

    Walaa Yas Lahmood

    2017-07-01

    Full Text Available Studied effect serial concentrations from spores filtrate of fungus Entomophthora muscae on some larval roles of musca domestica in laboratory. Results were made clear that the insect roles are sensitive to fungus, and treated the food larva of musca domestica and sprinkle it by concentration 2.8×106 , 2.8×107, 2.8×108 (spore/ml has led to get rates of destruction of cumulative faculty certified on the concentration and time its magnitude 16.60 , 47.67, 53.30 % respectively , also recorded some phenotypic distortion infected dead larva represent by contraction and blackening body. The treatment of pupael by sprinkling the previous fungus concentration recorded rate of destruction of accumulative faculty its magnitude 13.33, 26.67, 33.33% respectively, also the rates emergence of adults ranged between 66.67 – 86.67 % in comparison with rates of emergence of adults in control treatment 96.67% The results are made clear that adults treatment by sprinkle with last concentration from fungus spore filtrate recorded rates of distraction its magnitude 46.61, 56.67, 70% respectively after one week from treatment .

  2. Pertumbuhan dan Reproduksi Lalat Musca domestica pada Berbagai Media Perkembangbiakan

    Directory of Open Access Journals (Sweden)

    Endang Puji Astuti

    2013-02-01

    Full Text Available Abstract. Musca domestica was insect that disturbing human and other animal. Intensity M. Domestica with human living includes public healthy. The aim of research is to observe succeed of Mdomestica in breeding wether difJerent place. Larva growth in each stadia was different, 2-4 days average. Its contributed by humidity. On dry container, pupae that succes eksklosi only 50%. Presentation offood show difJerences oflarvae development. 3rd stage of larvae that has enough food is 17mm in length and 12mm in length for larvae with less food. Salty water make larvae growing faster than water without salto Development of Musca domestica in laboratory injluenced by high humidity, preset of food and adaptation of Musca domestica its self.Keywords : Musca domestica, rearing, development, humidity, food, salt - water

  3. swot: Super W Of Theta

    Science.gov (United States)

    Coupon, Jean; Leauthaud, Alexie; Kilbinger, Martin; Medezinski, Elinor

    2017-07-01

    SWOT (Super W Of Theta) computes two-point statistics for very large data sets, based on “divide and conquer” algorithms, mainly, but not limited to data storage in binary trees, approximation at large scale, parellelization (open MPI), and bootstrap and jackknife resampling methods “on the fly”. It currently supports projected and 3D galaxy auto and cross correlations, galaxy-galaxy lensing, and weighted histograms.

  4. INFECTIVITY OF TWO MEMBERS OF THE ENTOMOPHTHORA MUSCAE COMPLEX [ZYGOMYCETES: ENTOMOPHTHORALES] FOR MUSCA DOMESTICA [DIPT.: MUSCIDAE

    DEFF Research Database (Denmark)

    Bellini, R; Mullens, B A; Jespersen, J B

    1992-01-01

    Dose-mortality studies were conducted with 2 members of the Entomophthora muscae (Cohn) Fresenius complex from southern California (CA) and Denmark (DA) infecting house flies, Musca domestica L., from southern California. Primary conidia of the DA form were significantly more infective (LC50 = 34...

  5. Theta vectors and quantum theta functions

    International Nuclear Information System (INIS)

    Chang-Young, Ee; Kim, Hoil

    2005-01-01

    In this paper, we clarify the relation between Manin's quantum theta function and Schwarz's theta vector. We do this in comparison with the relation between the kq representation, which is equivalent to the classical theta function, and the corresponding coordinate space wavefunction. We first explain the equivalence relation between the classical theta function and the kq representation in which the translation operators of the phase space are commuting. When the translation operators of the phase space are not commuting, then the kq representation is no longer meaningful. We explain why Manin's quantum theta function, obtained via algebra (quantum torus) valued inner product of the theta vector, is a natural choice for the quantum version of the classical theta function. We then show that this approach holds for a more general theta vector containing an extra linear term in the exponent obtained from a holomorphic connection of constant curvature than the simple Gaussian one used in Manin's construction

  6. A model for the massive binary V340 Muscae

    Science.gov (United States)

    Hauck, Norbert

    2016-02-01

    A synthetic light curve has been fitted to photometric data from the ASAS-3 database. The parameters of the best solution are well consistent with those derived from stellar models for both components for an initial metallicity Z=0.020 and a common age of 5 Myr. Therefore, we can reliably estimate the absolute dimensions of this close eclipsing binary system. Apparently, the O-type primary star has a mass of about 22.65 Msun and a radius of 10.35 Rsun. For the secondary star, likely a late B-type dwarf, we obtain about 3.1 Msun and 2.1 Rsun. Their mass ratio of about 0.138 might be the lowest found so far in O-type binaries. [English and German online-version of this paper available under www.bav-astro.eu/rb/rb2016-2/1.html].

  7. Filamentary structure and magnetic field orientation in Musca

    Science.gov (United States)

    Cox, N. L. J.; Arzoumanian, D.; André, Ph.; Rygl, K. L. J.; Prusti, T.; Men'shchikov, A.; Royer, P.; Kóspál, Á.; Palmeirim, P.; Ribas, A.; Könyves, V.; Bernard, J.-Ph.; Schneider, N.; Bontemps, S.; Merin, B.; Vavrek, R.; Alves de Oliveira, C.; Didelon, P.; Pilbratt, G. L.; Waelkens, C.

    2016-05-01

    Herschel has shown that filamentary structures are ubiquitous in star-forming regions, in particular in nearby molecular clouds associated with Gould's Belt. High dynamic range far-infrared imaging of the Musca cloud with SPIRE and PACS reveals at least two types of filamentary structures: (1) the main ~10-pc scale high column-density linear filament; and (2) low column-density striations in close proximity to the main filament. In addition, we find features with intermediate column densities (hair-like strands) that appear physically connected to the main filament. We present an analysis of this filamentary network traced by Herschel and explore its connection with the local magnetic field. We find that both the faint dust emission striations and the plane-of-the-sky (POS) magnetic field are locally oriented close to perpendicular to the high-density main filament (position angle ~25-35°). The low-density striations and strands are oriented parallel to the POS magnetic field lines, which are derived previously from optical polarization measurements of background stars and more recently from Planck observations of dust polarized emission. The position angles are 97 ± 25°, 105 ± 7°, and 105 ± 5°. From these observations, we propose a scenario in which local interstellar material in this cloud has condensed into a gravitationally-unstable filament (with "supercritical" mass per unit length) that is accreting background matter along field lines through the striations. We also compare the filamentary structure in Musca with what is seen in similar Herschel observations of the Taurus B211/3 filament system and find that there is significantly less substructure in the Musca main filament than in the B211/3 filament. We suggest that the Musca cloud may represent an earlier evolutionary stage in which the main filament has not yet accreted sufficient mass and energy to develop a multiple system of intertwined filamentary components. Herschel is an ESA space

  8. The Musca cloud: A 6 pc-long velocity-coherent, sonic filament

    Science.gov (United States)

    Hacar, A.; Kainulainen, J.; Tafalla, M.; Beuther, H.; Alves, J.

    2016-03-01

    Filaments play a central role in the molecular clouds' evolution, but their internal dynamical properties remain poorly characterized. To further explore the physical state of these structures, we have investigated the kinematic properties of the Musca cloud. We have sampled the main axis of this filamentary cloud in 13CO and C18O (2-1) lines using APEX observations. The different line profiles in Musca shows that this cloud presents a continuous and quiescent velocity field along its ~6.5 pc of length. With an internal gas kinematics dominated by thermal motions (I.e. σNT/cs ≲ 1) and large-scale velocity gradients, these results reveal Musca as the longest velocity-coherent, sonic-like object identified so far in the interstellar medium. The transonic properties of Musca present a clear departure from the predicted supersonic velocity dispersions expected in the Larson's velocity dispersion-size relationship, and constitute the first observational evidence of a filament fully decoupled from the turbulent regime over multi-parsec scales. This publication is based on data acquired with the Atacama Pathfinder Experiment (APEX). APEX is a collaboration between the Max-Planck-Institut fuer Radioastronomie, the European Southern Observatory, and the Onsala Space Observatory (ESO programme 087.C-0583).The reduced datacubes as FITS files are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/587/A97

  9. Optical Interferometric Observations of Theta1 Orionis C from NPOI and Implications for the System Orbit (Preprint)

    National Research Council Canada - National Science Library

    Patience, J; Zavala, R. T; Prato, L; Franz, O; Wasserman, L; Tycner, C; Hutter, D. J; Hummel, C. A

    2007-01-01

    With the Navy Prototype Optical Interferometer (NPOI), the binary system Theta 1 Orionis C, the most massive member of the Trapezium, was spatially resolved over a time period extending from February 2006 to March 2007...

  10. A new semidefinite programming relaxation for cycles in binary matroids and cuts in graphs

    NARCIS (Netherlands)

    Gouveia, J.; Laurent, M.; Parrilo, P.; Thomas, R.

    2012-01-01

    The theta bodies of a polynomial ideal are a series of semidefinite programming relaxations of the convex hull of the real variety of the ideal. In this paper we construct the theta bodies of the vanishing ideal of cycles in a binary matroid. Applied to cuts in graphs, this yields a new hierarchy of

  11. The 1984 eclipse of the symbiotic binary SY Muscae

    Science.gov (United States)

    Kenyon, S. J.; Michalitisianos, A. G.; Lutz, J. H.; Kafatos, M.

    1985-01-01

    Data from IUE spectra obtained with the 10 x 20-arcsec aperture on May 13, 1984, and optical spectrophotometry obtained with an SIT vidicon on the 1.5-m telescope at CTIO on April 29-May 1, 1984, are reported for the symbiotic binary SY Mus. The data are found to be consistent with a model of a red-giant secondary of 60 solar radii which completely eclipses the hot primary every 627 d but only partially eclipses the 75-solar-radius He(+) region surrounding the primary. The distance to SY Mus is estimated as 1.3 kpc. It is suggested that the large Balmer decrement in eclipse, with (H-alpha)/(H-beta) = 8.3 and (H-beta)/(H-gamma) = 1.5, is associated with an electron density of about 10 to the 10th/cu cm.

  12. Circadian rhytm in the house fly (Musca domestica)

    OpenAIRE

    BAZALOVÁ, Olga

    2010-01-01

    In this thesis the expression pattern of five circadian clock genes (cwo, pdp 1{$\\varepsilon$}, ck 1{$\\varepsilon$}, ck 2{$\\beta$} and pdh) was studied in the housefly (Musca domestica). The influence of temperature on the expression pattern of these five genes and of two others genes, per and tim, was examined. The locomotor activity of flies exposed to three different temperature conditions was studied.

  13. Field Studies of Entomophthora (Zygomycetes: Entomophthorales)-Induced Behavioral Fever in Musca domestica (Diptera: Muscidae) in Denmark

    DEFF Research Database (Denmark)

    Kalsbeek, V.; Mullens, Bradley A.; Jespersen, Jørgen Brøchner

    2001-01-01

    House flies were collected over 3 days (three to five times per day) from specific sites on a dairy farm with a range of high to low temperatures. Flies were held individually to determine whether the distribution of fungus-infected (Entomophthora muscae and E. schizophorae) house flies differed ...... that behavioral fever occurs in the field for flies infected with both E. muscae and E. schizophorae and that flies can cure themselves of infection through the use of artificial heat sources....

  14. Cortical theta wanes for language.

    Science.gov (United States)

    Hermes, Dora; Miller, Kai J; Vansteensel, Mariska J; Edwards, Erik; Ferrier, Cyrille H; Bleichner, Martin G; van Rijen, Peter C; Aarnoutse, Erik J; Ramsey, Nick F

    2014-01-15

    The role of low frequency oscillations in language areas is not yet understood. Using ECoG in six human subjects, we studied whether different language regions show prominent power changes in a specific rhythm, in similar manner as the alpha rhythm shows the most prominent power changes in visual areas. Broca's area and temporal language areas were localized in individual subjects using fMRI. In these areas, the theta rhythm showed the most pronounced power changes and theta power decreased significantly during verb generation. To better understand the role of this language-related theta decrease, we then studied the interaction between low frequencies and local neuronal activity reflected in high frequencies. Amplitude-amplitude correlations showed that theta power correlated negatively with high frequency activity, specifically across verb generation trials. Phase-amplitude coupling showed that during control trials, high frequency power was coupled to theta phase, but this coupling decreased significantly during verb generation trials. These results suggest a dynamic interaction between the neuronal mechanisms underlying the theta rhythm and local neuronal activity in language areas. As visual areas show a pronounced alpha rhythm that may reflect pulsed inhibition, language regions show a pronounced theta rhythm with highly similar features. © 2013.

  15. Entomophthora muscae — moisture as a factor affecting its transmission and conidial germination

    Directory of Open Access Journals (Sweden)

    John P. Kramer

    2014-08-01

    Full Text Available The role played by moisture in the transmission of Entomophthora muscae and in the germination of its conidia was investigated. A majority of adult house flies exposed to conidial showers that fell upon surfaces covered with droplets of condensation acquired the parasite, while no flies exposed to conidial showers that fell upon dry surfaces did so. A microscopical study of conidial showers showed that germination was practically non-existent on dry surfaces while a vast majority of conidia that fell upon a droplet-covered surface germinated. A method for the in vivo culture of E. muscae was developpd and 11 serial passages of the fungus were achieved. Resting spores rather than conidia became the dominant form produced in the cadavers, and flies in a twelfth group remained unifected.

  16. {theta}-Compactness in L-topological spaces

    Energy Technology Data Exchange (ETDEWEB)

    Hanafy, I.M. [Department of Mathematics, Faculty of Education, Suez Canal University, El-Arish (Egypt)], E-mail: ihanafy@hotmail.com

    2009-12-15

    Recently, El-Naschie has shown that the notion of fuzzy topology may be relevant to quantum particle physics in connection with string theory and e{sup {infinity}} theory. In 2005, Caldas and Jafari have introduced {theta}-compact fuzzy topological spaces. In this paper, the concepts of{theta}-compactness, countable{theta}-compactness and the{theta}-Lindeloef property are introduced and studied in L-topological spaces, where L is a complete de Morgan algebra. They are defined by means of{theta}-openL-sets and their inequalities. They does not rely on the structure of basis lattice L and no distributivity in L is required. They can also be characterized by{theta}-closedL-sets and their inequalities. When L is a completely de Morgan algebra, their many characterizations are presented.

  17. Traveling Theta Waves in the Human Hippocampus

    Science.gov (United States)

    Zhang, Honghui

    2015-01-01

    The hippocampal theta oscillation is strongly correlated with behaviors such as memory and spatial navigation, but we do not understand its specific functional role. One hint of theta's function came from the discovery in rodents that theta oscillations are traveling waves that allow parts of the hippocampus to simultaneously exhibit separate oscillatory phases. Because hippocampal theta oscillations in humans have different properties compared with rodents, we examined these signals directly using multielectrode recordings from neurosurgical patients. Our findings confirm that human hippocampal theta oscillations are traveling waves, but also show that these oscillations appear at a broader range of frequencies compared with rodents. Human traveling waves showed a distinctive pattern of spatial propagation such that there is a consistent phase spread across the hippocampus regardless of the oscillations' frequency. This suggests that traveling theta oscillations are important functionally in humans because they coordinate phase coding throughout the hippocampus in a consistent manner. SIGNIFICANCE STATEMENT We show for the first time in humans that hippocampal theta oscillations are traveling waves, moving along the length of the hippocampus in a posterior–anterior direction. The existence of these traveling theta waves is important for understanding hippocampal neural coding because they cause neurons at separate positions in the hippocampus to experience different theta phases simultaneously. The theta phase that a neuron measures is a key factor in how that cell represents behavioral information. Therefore, the existence of traveling theta waves indicates that, to fully understand how a hippocampal neuron represents information, it is vital to also account for that cell's location in addition to conventional measures of neural activity. PMID:26354915

  18. Interaction of some organophosphorus compounds in susceptible and resistant houseflies (Musca domestica L.)

    NARCIS (Netherlands)

    Abdallah, M.D.

    1963-01-01

    The effect of tri-ortho-cresylphosphate (TOCP) on poisoning by parathion and paraoxon in susceptible and resistant houseflies (Musca domestica L.) was investigated.

    TOCP influenced the penetration of parathion and paraoxon, and this could explain the contradictory results of both an

  19. Temperature and Population Density Effects on Locomotor Activity of Musca domestica (Diptera: Muscidae)

    DEFF Research Database (Denmark)

    Schou, T. M.; Faurby, S.; Kjærsgaard, A.

    2013-01-01

    The behavior of ectotherm organisms is affected by both abiotic and biotic factors. However, a limited number of studies have investigated the synergistic effects on behavioral traits. This study examined the effect of temperature and density on locomotor activity of Musca domestica (L.). Locomot...

  20. Three-dimensional ideal theta(1)/theta(2) angular transformer and its uses in fiber optics.

    Science.gov (United States)

    Ning, X

    1988-10-01

    A 3-D ideal theta(1)/theta(2) angular transformer in nonimaging optics is introduced. The axially symmetric transformer, combining a portion of a hyperbolic concentrator with two lenses, transforms an input limited Lambertian over an angle theta(1) to an output limited Lambertian over an angle theta(2) without losing throughput. This is the first known transformer with such ideal properties. Results of computer simulations of a transformer with planospherical lenses are presented. Because of its ideal angular transforming property, the transformer offers an excellent solution for power launching and fiber-fiber coupling in optical fiber systems. In principle, the theoretical maximum coupling efficiency based on radiance conservation can be achieved with this transformer. Several conceptual designs of source-fiber and fiber-fiber couplers using the transformer are given.

  1. Adaptation of Musca domestica L. field population to laboratory breeding causes transcriptional alterations

    DEFF Research Database (Denmark)

    Højland, Dorte H.; Vagn Jensen, Karl-Martin; Kristensen, Michael

    2014-01-01

    The housefly, Musca domestica, has developed resistance to most insecticides applied for its control. Expression of genes coding for detoxification enzymes play a role in the response of the housefly when encountered by a xenobiotic. The highest level of constitutive gene expression of nine P450 ...

  2. Theta-Generalized closed sets in fuzzy topological spaces

    International Nuclear Information System (INIS)

    El-Shafei, M.E.; Zakari, A.

    2006-01-01

    In this paper we introduce the concepts of theta-generalized closed fuzzy sets and generalized fuzzy sets in topological spaces. Furthermore, generalized fuzzy sets are extended to theta-generalized fuzzy sets. Also, we introduce the concepts of fuzzy theta-generalized continuous and fuzzy theta-generalized irresolute mappings. (author)

  3. Harnessing the power of theta: natural manipulations of cognitive performance during hippocampal theta-contingent eyeblink conditioning

    Science.gov (United States)

    Hoffmann, Loren C.; Cicchese, Joseph J.; Berry, Stephen D.

    2015-01-01

    Neurobiological oscillations are regarded as essential to normal information processing, including coordination and timing of cells and assemblies within structures as well as in long feedback loops of distributed neural systems. The hippocampal theta rhythm is a 3–12 Hz oscillatory potential observed during cognitive processes ranging from spatial navigation to associative learning. The lower range, 3–7 Hz, can occur during immobility and depends upon the integrity of cholinergic forebrain systems. Several studies have shown that the amount of pre-training theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning. Our lab has used a brain-computer interface (BCI) that delivers eyeblink conditioning trials contingent upon the explicit presence or absence of hippocampal theta. A behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to four-fold increase in learning speed. This behavioral effect is accompanied by enhanced amplitude and synchrony of hippocampal local field potential (LFP)s, multi-unit excitation, and single-unit response patterns that depend on theta state. Additionally, training in the presence of hippocampal theta has led to increases in the salience of tone-induced unit firing patterns in the medial prefrontal cortex, followed by persistent multi-unit activity during the trace interval. In cerebellum, rhythmicity and precise synchrony of stimulus time-locked LFPs with those of hippocampus occur preferentially under the theta condition. Here we review these findings, integrate them into current models of hippocampal-dependent learning and suggest how improvement in our understanding of neurobiological oscillations is critical for theories of medial temporal lobe processes underlying intact and pathological learning. PMID:25918501

  4. Harnessing the power of theta: natural manipulations of cognitive performance during hippocampal theta-contingent eyeblink conditioning.

    Science.gov (United States)

    Hoffmann, Loren C; Cicchese, Joseph J; Berry, Stephen D

    2015-01-01

    Neurobiological oscillations are regarded as essential to normal information processing, including coordination and timing of cells and assemblies within structures as well as in long feedback loops of distributed neural systems. The hippocampal theta rhythm is a 3-12 Hz oscillatory potential observed during cognitive processes ranging from spatial navigation to associative learning. The lower range, 3-7 Hz, can occur during immobility and depends upon the integrity of cholinergic forebrain systems. Several studies have shown that the amount of pre-training theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning. Our lab has used a brain-computer interface (BCI) that delivers eyeblink conditioning trials contingent upon the explicit presence or absence of hippocampal theta. A behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to four-fold increase in learning speed. This behavioral effect is accompanied by enhanced amplitude and synchrony of hippocampal local field potential (LFP)s, multi-unit excitation, and single-unit response patterns that depend on theta state. Additionally, training in the presence of hippocampal theta has led to increases in the salience of tone-induced unit firing patterns in the medial prefrontal cortex, followed by persistent multi-unit activity during the trace interval. In cerebellum, rhythmicity and precise synchrony of stimulus time-locked LFPs with those of hippocampus occur preferentially under the theta condition. Here we review these findings, integrate them into current models of hippocampal-dependent learning and suggest how improvement in our understanding of neurobiological oscillations is critical for theories of medial temporal lobe processes underlying intact and pathological learning.

  5. Other characterizations of $\\beta$-$\\theta$-R0 topological spaces

    OpenAIRE

    Miguel Caldas Cueva

    2013-01-01

    In this paper we give other characterizations of $\\beta$-$\\theta$-$%R_0$ and also introduce a new separation axiom called$\\beta$-$\\theta$-$R_1$. It turns out that $\\beta$-$\\theta$-$R_1$ isstronger that $\\beta$-$\\theta$-$R_0$

  6. Better than sleep: theta neurofeedback training accelerates memory consolidation.

    Science.gov (United States)

    Reiner, Miriam; Rozengurt, Roman; Barnea, Anat

    2014-01-01

    Consistent empirical results showed that both night and day sleep enhanced memory consolidation. In this study we explore processes of consolidation of memory during awake hours. Since theta oscillations have been shown to play a central role in exchange of information, we hypothesized that elevated theta during awake hours will enhance memory consolidation. We used a neurofeedback protocol, to enhance the relative power of theta or beta oscillations. Participants trained on a tapping task, were divided into three groups: neurofeedback theta; neurofeedback beta; control. We found a significant improvement in performance in the theta group, relative to the beta and control groups, immediately after neurofeedback. Performance was further improved after night sleep in all groups, with a significant advantage favoring the theta group. Theta power during training was correlated with the level of improvement, indicating a clear relationship between memory consolidation, and theta neurofeedback. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Artificial theta stimulation impairs encoding of contextual fear memory.

    Directory of Open Access Journals (Sweden)

    Arto Lipponen

    Full Text Available Several experiments have demonstrated an intimate relationship between hippocampal theta rhythm (4-12 Hz and memory. Lesioning the medial septum or fimbria-fornix, a fiber track connecting the hippocampus and the medial septum, abolishes the theta rhythm and results in a severe impairment in declarative memory. To assess whether there is a causal relationship between hippocampal theta and memory formation we investigated whether restoration of hippocampal theta by electrical stimulation during the encoding phase also restores fimbria-fornix lesion induced memory deficit in rats in the fear conditioning paradigm. Male Wistar rats underwent sham or fimbria-fornix lesion operation. Stimulation electrodes were implanted in the ventral hippocampal commissure and recording electrodes in the septal hippocampus. Artificial theta stimulation of 8 Hz was delivered during 3-min free exploration of the test cage in half of the rats before aversive conditioning with three foot shocks during 2 min. Memory was assessed by total freezing time in the same environment 24 h and 28 h after fear conditioning, and in an intervening test session in a different context. As expected, fimbria-fornix lesion impaired fear memory and dramatically attenuated hippocampal theta power. Artificial theta stimulation produced continuous theta oscillations that were almost similar to endogenous theta rhythm in amplitude and frequency. However, contrary to our predictions, artificial theta stimulation impaired conditioned fear response in both sham and fimbria-fornix lesioned animals. These data suggest that restoration of theta oscillation per se is not sufficient to support memory encoding after fimbria-fornix lesion and that universal theta oscillation in the hippocampus with a fixed frequency may actually impair memory.

  8. Lower trait frontal theta activity in mindfulness meditators

    Directory of Open Access Journals (Sweden)

    Guaraci Ken Tanaka

    2014-09-01

    Full Text Available Acute and long-term effects of mindfulness meditation on theta-band activity are not clear. The aim of this study was to investigate frontal theta differences between long- and short-term mindfulness practitioners before, during, and after mindfulness meditation. Twenty participants were recruited, of which 10 were experienced Buddhist meditators. Despite an acute increase in the theta activity during meditation in both the groups, the meditators showed lower trait frontal theta activity. Therefore, we suggested that this finding is a neural correlate of the expert practitioners’ ability to limit the processing of unnecessary information (e.g., discursive thought and increase the awareness of the essential content of the present experience. In conclusion, acute changes in the theta band throughout meditation did not appear to be a specific correlate of mindfulness but were rather related to the concentration properties of the meditation. Notwithstanding, lower frontal theta activity appeared to be a trait of mindfulness practices.

  9. Quantum thetas on noncommutative T4 from embeddings into lattice

    International Nuclear Information System (INIS)

    Chang-Young, Ee; Kim, Hoil

    2007-01-01

    In this paper, we investigate the theta vector and quantum theta function over noncommutative T 4 from the embedding of RxZ 2 . Manin has constructed the quantum theta functions from the lattice embedding into vector space (x finite group). We extend Manin's construction of the quantum theta function to the embedding of vector space x lattice case. We find that the holomorphic theta vector exists only over the vector space part of the embedding, and over the lattice part we can only impose the condition for the Schwartz function. The quantum theta function built on this partial theta vector satisfies the requirement of the quantum theta function. However, two subsequent quantum translations from the embedding into the lattice part are nonadditive, contrary to the additivity of those from the vector space part

  10. Search for the exotic $\\Theta^+$ resonance in the NOMAD experiment

    CERN Document Server

    Samoylov, O; Autiero, D; Baldisseri, Alberto; Baldo-Ceolin, M; Banner, M; Bassompierre, G; Benslama, K; Besson, N; Bird, I; Blumenfeld, B; Bobisut, F; Bouchez, J; Boyd, S; Bueno, A; Bunyatov, S; Camilleri, L L; Cardini, A; Cattaneo, P W; Cavasinni, V; Cervera-Villanueva, A; Challis, R; Chukanov, A; Collazuol, G; Conforto, G; Conta, C; Contalbrigo, M; Cousins, R; Daniels, D; De Santo, A; Degaudenzi, H M; Del Prete, T; Di Lella, L; Dignan, T; Do Couto e Silva, E; Dumarchez, J; Ellis, M; Feldman, G J; Ferrari, R; Ferrère, D; Flaminio, V; Fraternali, M; Gaillard, J M; Gangler, E; Geiser, A; Geppert, D; Gibin, D; Gninenko, S; Godley, A; Gosset, J; Gouanère, M; Grant, A; Graziani, G; Guglielmi, A M; Gómez-Cadenas, J J; Gössling, C; Hagner, C; Hernando, J; Hubbard, D; Hurst, P; Hyett, N; Iacopini, E; Joseph, C; Juget, F; Kent, N; Kirsanov, M; Klimov, O; Kokkonen, J; Kovzelev, A; Krasnoperov, A V; La Rotonda, L; Lacaprara, S; Lachaud, C; Lakic, B; Lanza, A; Laveder, M; Letessier-Selvon, A A; Linssen, L; Ljubicic, A; Long, J; Lupi, A; Lyubushkin, V; Lévy, J M; Marchionni, A; Martelli, F; Mendiburu, J P; Meyer, J P; Mezzetto, M; Mishra, S R; Moorhead, G F; Méchain, X; Naumov, D; Nefedov, Yu; Nguyen-Mau, C; Nédélec, P; Orestano, D; Pastore, F; Peak, L S; Pennacchio, E; Pessard, H; Petti, R; Placci, A; Polesello, G; Pollmann, D; Polyarush, A Yu; Popov, B; Poulsen, C; Rebuffi, L; Rico, J; Riemann, P; Roda, C; Rubbia, André; Salvatore, F; Schahmaneche, K; Schmidt, B; Schmidt, T; Sconza, A; Sevior, M; Sillou, D; Soler, F J P; Sozzi, G; Steele, D; Stiegler, U; Stipcevic, M; Stolarczyk, T; Tareb-Reyes, M; Taylor, G N; Tereshchenko, V V; Toropin, A; Touchard, A M; Tovey, S N; Tran, M T; Tsesmelis, E; Ulrichs, J; Vacavant, L; Valdata-Nappi, M; Valuev, V; Vannucci, F; Varvell, K E; Veltri, M; Vercesi, V; Vidal-Sitjes, G; Vieira, J M; Vinogradova, T; Weber, F V; Weisse, T; Wilson, F F; Winton, L J; Yabsley, B D; Zaccone, Henri; Zuber, K; Zuccon, P

    2007-01-01

    A search for exotic Theta baryon via Theta -> proton +Ks decay mode in the NOMAD muon neutrino DIS data is reported. The special background generation procedure was developed. The proton identification criteria are tuned to maximize the sensitivity to the Theta signal as a function of xF which allows to study the Theta production mechanism. We do not observe any evidence for the Theta state in the NOMAD data. We provide an upper limit on Theta production rate at 90% CL as 2.13 per 1000 of neutrino interactions.

  11. Kinetic description of linear theta-pinch equilibria

    International Nuclear Information System (INIS)

    Batchelor, D.B.; Davidson, R.C.

    1975-01-01

    Equilibrium properties of linear theta-pinch plasmas are studied within the framework of the steady-state (o/x=0) Vlasov-Maxwell equations. The analysis is carried out for an infinitely long plasma column aligned parallel to an externally applied axial magnetic field Bsub(z)sup(ext)esub(z). Equilibrium properties are calculated for the class of rigid-rotor Vlasov equilibria, in which the th component distribution function (Hsub(perpendicular), Psub(theta), upsilonsub(z) depends on perpendicular energy H and canonical angular momentum Psub(theta), exclusively through the linear combination Hsub(perpendicular)-ωsub(j)Psub(theta), where ω;=const.=angular velocity of mean rotation. General equilibrium relations that pertain to the entire class of rigid-rotor Vlasov equilibria are discussed; and specific examples of sharp- and diffuse-boundary equilibrium configurations are considered. Rigid-rotor density and magnetic field profiles are compared with experimentally observed profiles. A general prescription is given for determining the functional dependence of the equilibrium distribution function on Hsub(perpendicular)-ωsub(j)Psub(theta) in circumstances, where the density profile or magnetic field profile is specified. (author)

  12. Evaluation of the house fly Musca domestica as a mechanical vector for an anthrax.

    Directory of Open Access Journals (Sweden)

    Antonio Fasanella

    Full Text Available Anthrax is a disease of human beings and animals caused by the encapsulated, spore-forming, Bacillus anthracis. The potential role of insects in the spread of B. anthracis to humans and domestic animals during an anthrax outbreak has been confirmed by many studies. Among insect vectors, the house fly Musca domestica is considered a potential agent for disease transmission. In this study, laboratory-bred specimens of Musca domestica were infected by feeding on anthrax-infected rabbit carcass or anthrax contaminated blood, and the presence of anthrax spores in their spots (faeces and vomitus was microbiologically monitored. It was also evaluated if the anthrax spores were able to germinate and replicate in the gut content of insects. These results confirmed the role of insects in spreading anthrax infection. This role, although not major, given the huge size of fly populations often associated with anthrax epidemics in domestic animals, cannot be neglected from an epidemiological point of view and suggest that fly control should be considered as part of anthrax control programs.

  13. The theta-structure in string theories - 1: bosonic strings

    International Nuclear Information System (INIS)

    Li Miao.

    1985-09-01

    We explored the theta-structures in bosonic string theories which are similar to those in gauge field theories. The theta-structure of string is due to the multiply connected spatial compact subspace of space-time. The work of this paper shows that there is an energy band E(theta) in the string theory and one may move the tachyon out in theory by choosing some proper theta parameters. (author)

  14. Quantum thetas on noncommutative Td with general embeddings

    International Nuclear Information System (INIS)

    Chang-Young, Ee; Kim, Hoil

    2008-01-01

    In this paper, we construct quantum theta functions over noncommutative T d with general embeddings. Manin has constructed quantum theta functions from the lattice embedding into vector space x finite group. We extend Manin's construction of quantum thetas to the case of general embedding of vector space x lattice x torus. It turns out that only for the vector space part of the embedding there exists the holomorphic theta vector, while for the lattice part there does not. Furthermore, the so-called quantum translations from embedding into the lattice part become non-additive, while those from the vector space part are additive

  15. Melia azedarach L. extracts and their activity on Musca domestica L. (Diptera: Muscidae

    Directory of Open Access Journals (Sweden)

    Marise M. O. Cabral

    Full Text Available Crudes extracts and fractions from seeds of Melia azedarach L. (Meliaceae have been assayed on Musca domestica Linnaeus, 1758 (Diptera: Muscidae. Thus, the post-embryonic development of the flies was reduced and the delay from newly hatched larvae to adults had significant increase. In addition, the pupal weights were reduced and the sexual ratio altered. Toxicity to fly eggs was also observed.

  16. Long-term plasticity is proportional to theta-activity.

    Directory of Open Access Journals (Sweden)

    Marian Tsanov

    Full Text Available BACKGROUND: Theta rhythm in the hippocampal formation is a main feature of exploratory behaviour and is believed to enable the encoding of new spatial information and the modification of synaptic weights. Cyclic changes of dentate gyrus excitability during theta rhythm are related to its function, but whether theta epochs per se are able to alter network properties of dentate gyrus for long time-periods is still poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: We used low-frequency stimulation protocols that amplify the power of endogenous theta oscillations, in order to estimate the plasticity effect of endogenous theta oscillations on a population level. We found that stimulation-induced augmentation of the theta rhythm is linked to a subsequent increase of neuronal excitability and decrease of the synaptic response. This EPSP-to-Spike uncoupling is related to an increased postsynaptic spiking on the positive phases of theta frequency oscillations. Parallel increase of the field EPSP slope and the population spike occurs only after concurrent pre- and postsynaptic activation. Furthermore, we observed that long-term potentiation (>24 h occurs in the dentate gyrus of freely behaving adult rats after phasic activity of entorhinal afferents in the theta-frequency range. This plasticity is proportional to the field bursting activity of granule cells during the stimulation, and may comprise a key step in spatial information transfer. Long-term potentiation of the synaptic component occurs only when the afferent stimulus precedes the evoked population burst, and is input-specific. CONCLUSIONS/SIGNIFICANCE: Our data confirm the role of the dentate gyrus in filtering information to the subsequent network during the activated state of the hippocampus.

  17. Diffusive flux of energy in binary mixtures

    International Nuclear Information System (INIS)

    Sampaio, R.S.

    1976-04-01

    The diffusive flux of energy j tilde is studied through the reduced diffusive flux of energy K tilde, which obeys equations of the form: sim(delta K tilde/delta grad rho sub(α))= sim(delta K tilde/delta grad theta)=0. By a representation theorem, herein proved, is obtained a general representation for K tilde which is simplified, for the case of binary mixtures, using the principle of objectivity. Some consequences of this representation are discussed such as the symmetry of the partial stresses T 1 tilde and T 2 tilde and the difference between the normal stresses [pt

  18. Ramanujan's theta functions

    CERN Document Server

    Cooper, Shaun

    2017-01-01

    Theta functions were studied extensively by Ramanujan. This book provides a systematic development of Ramanujan’s results and extends them to a general theory. The author’s treatment of the subject is comprehensive, providing a detailed study of theta functions and modular forms for levels up to 12. Aimed at advanced undergraduates, graduate students, and researchers, the organization, user-friendly presentation, and rich source of examples, lends this book to serve as a useful reference, a pedagogical tool, and a stimulus for further research. Topics, especially those discussed in the second half of the book, have been the subject of much recent research; many of which are appearing in book form for the first time. Further results are summarized in the numerous exercises at the end of each chapter.

  19. Quantum Thetas on Noncommutative T^d with General Embeddings

    OpenAIRE

    Chang-Young, Ee; Kim, Hoil

    2007-01-01

    In this paper we construct quantum theta functions over noncommutative T^d with general embeddings. Manin has constructed quantum theta functions from the lattice embedding into vector space x finite group. We extend Manin's construction of quantum thetas to the case of general embedding of vector space x lattice x torus. It turns out that only for the vector space part of the embedding there exists the holomorphic theta vector, while for the lattice part there does not. Furthermore, the so-c...

  20. Distinct slow and fast cortical theta dynamics in episodic memory retrieval.

    Science.gov (United States)

    Pastötter, Bernhard; Bäuml, Karl-Heinz T

    2014-07-01

    Brain oscillations in the theta frequency band (3-8 Hz) have been shown to be critically involved in human episodic memory retrieval. In prior work, both positive and negative relationships between cortical theta power and retrieval success have been reported. This study examined the hypothesis that slow and fast cortical theta oscillations at the edges of the traditional theta frequency band are differentially related to retrieval success. Scalp EEG was recorded in healthy human participants as they performed a cued-recall episodic memory task. Slow (~3 Hz) and fast (~7 Hz) theta oscillations at retrieval were examined as a function of whether an item was recalled or not and as a function of the items' output position at test. Recall success typically declines with output position, due to increases in interference level. The results showed that slow theta power was positively related but fast theta power was negatively related to retrieval success. Concurrent positive and negative episodic memory effects for slow and fast theta oscillations were dissociable in time and space, showing different time courses and different spatial locations on the scalp. Moreover, fast theta power increased from early to late output positions, whereas slow theta power was unaffected by items' output position. Together with prior work, the results suggest that slow and fast theta oscillations have distinct functional roles in episodic memory retrieval, with slow theta oscillations being related to processes of recollection and conscious awareness, and fast theta oscillations being linked to processes of interference and interference resolution. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Staged theta pinch experiments

    International Nuclear Information System (INIS)

    Linford, R.K.; Downing, J.N.; Gribble, R.F.; Jacobson, A.R.; Platts, D.A.; Thomas, K.S.

    1976-01-01

    Two implosion heating circuits are being experimentally tested. The principal experiment in the program is the 4.5-m-long Staged Theta Pinch (STP). It uses two relatively low energy (50kJ and 100 kJ), high voltage (125 kV) capacitor banks to produce the theta pinch plasma inside the 20 cm i.d. quartz discharge tube. A lower voltage (50 kV), higher energy (750 kJ) capacitor bank is used to contain the plasma and provide a variable amount of adiabatic compression. Because the experiment produces a higher ratio of implosion heating to compressional heating than conventional theta pinches, it should be capable of producing high temperature plasmas with a much larger ratio of plasma radius to discharge tube radius than has been possible in the past. The Resonant Heating Experiment (RHX) in its initial configuration is the same as a 0.9-m-long section of the high voltage part of the STP experiment and all the plasma results here were obtained with the experiment in that configuration. Part of the implosion bank will be removed and a low inductance crowbar added to convert it to the resonant heating configuration. (U.K.)

  2. Theta power is reduced in healthy cognitive aging.

    Science.gov (United States)

    Cummins, Tarrant D R; Finnigan, Simon

    2007-10-01

    The effects of healthy cognitive aging on electroencephalographic (EEG) theta (4.9-6.8 Hz) power were examined during performance of a modified Sternberg, S., 1966. High-speed scanning in human memory. Science 153, 652-654.) word recognition task. In a sample of fourteen young (mean age 21.9 years, range=18-27) and fourteen older (mean age 68.4 years, range=60-80) participants, theta power was found to be significantly lower in older adults during both the retention and recognition intervals. This theta power difference was greatest at the fronto-central midline electrode and occurred in parallel with a small, non-significant decrease in recognition accuracy in the older sample. A significant decrease in older adults' mean theta power was also observed in resting EEG, however, it was of substantially smaller magnitude than the task-related theta difference. It is proposed that a neurophysiological measure(s), such as task-specific frontal midline theta (fmtheta) power, may be a more sensitive marker of cognitive aging than task performance measures. Furthermore, as recent research indicates that fmtheta is generated primarily in the anterior cingulate cortex, the current findings support evidence that the function of brain networks incorporating this structure may be affected in cognitive aging.

  3. Impaired theta-gamma coupling during working memory performance in schizophrenia.

    Science.gov (United States)

    Barr, Mera S; Rajji, Tarek K; Zomorrodi, Reza; Radhu, Natasha; George, Tony P; Blumberger, Daniel M; Daskalakis, Zafiris J

    2017-11-01

    Working memory deficits represent a core feature of schizophrenia. These deficits have been associated with dysfunctional dorsolateral prefrontal cortex (DLPFC) cortical oscillations. Theta-gamma coupling describes the modulation of gamma oscillations by theta phasic activity that has been directly associated with the ordering of information during working memory performance. Evaluating theta-gamma coupling may provide greater insight into the neural mechanisms mediating working memory deficits in this disorder. Thirty-eight patients diagnosed with schizophrenia or schizoaffective disorder and 38 healthy controls performed the verbal N-Back task administered at 4 levels, while EEG was recorded. Theta (4-7Hz)-gamma (30-50Hz) coupling was calculated for target and non-target correct trials for each working memory load. The relationship between theta-gamma coupling and accuracy was determined. Theta-gamma coupling was significantly and selectively impaired during correct responses to target letters among schizophrenia patients compared to healthy controls. A significant and positive relationship was found between theta-gamma coupling and 3-Back accuracy in controls, while this relationship was not observed in patients. These findings suggest that impaired theta-gamma coupling contribute to working memory dysfunction in schizophrenia. Future work is needed to evaluate the predictive utility of theta-gamma coupling as a neurophysiological marker for functional outcomes in this disorder. Copyright © 2017. Published by Elsevier B.V.

  4. X-Ray Transient in Musca (GRS 1121-68 = GS 1124-683)

    DEFF Research Database (Denmark)

    Lund, Niels; Brandt, Søren; Makino, F.

    1991-01-01

    Research Institute, Lyngby; and Space Research Institute, Moscow), report: "A new x-ray source in Musca, GRS 1121-68, has been discovered in data obtained by the WATCH detectors on Jan. 9. The spectrum of the source was harder than that of the Crab nebula, and the flux was about twice that from t...... was taken as La Silla, showing no new object in the 2 x 2 deg field brighter than mag 7-8; a search plate will be taken with the Schmidt telescope at La Silla....

  5. UJI EFIKASI LARVASIDA BERBAHAN AKTIF DICHLORVOS TERHADAP LARVA LALAT RUMAH Musca domestica DI LABORATORIUM

    Directory of Open Access Journals (Sweden)

    Hadi Suwasono

    2012-10-01

    Full Text Available The house fly, Musca domestica have been implicated in the mechanical transmission of pathogens causing diseases. Important diseases that may be transmitted under certain conditions include infection of virus, bacterial, protozoan, fungal and helminthic. Therefore control measures should be carried out only when the presence of the house fly is intolerable to humans due to their being a health hazard or nuisance. The larvicide with active ingredient of dichlorvos 250 g/l was applied to the house fly larvae which conducted in the laboratory. There were jive concentrations of larvicides to be tested i.e. 6; 12; 24; 48 and 96 ml by product/ 3 l of water/m2. A dried powder of chicken dung was utilized as larvae medium. The medium was inoculated with the third instar larvae then it sprayed with the larvicide suspension. All larvicidal assays were carried out at 26 - 30°C temperature and 60-80% RH in the laboratory. The results revealed that all of the five tested concentrations yielded between 0 and 5.2 percent larval mortalities.   Keywords: house fly, Musca domestica, larvicide, dichlorvos

  6. Molecular detection and antimicrobial resistance of Aeromonas from houseflies (Musca domestica in Iran

    Directory of Open Access Journals (Sweden)

    Davood Ommi

    2015-11-01

    Full Text Available Objective. This study aimed to report the molecular detection and antimicrobial resistance of Aeromonas among houseflies (Musca domestica in Shahrekord and Isfahan provinces of Iran. Materials and methods. Flies were caught from household kitchens, cattle farms, animal hospitals, human hospitals, slaughter house and poultry farms and put in collection separate sterile tubes. Isolation was accomplished by culture of flies in alkaline peptone water followed by identification with Aeromonas-specific Polymerase Chain Reaction (PCR. Results. Out of 600 houseflies 73 (12.2% were infected with Aeromonas spp. Significantly higher frequencies of Aeromonas were isolated in Shahrekord province (13.0%; 39/300 than in Isfahan province (11.3%; 34/300. The recovery frequencies of the organisms were significantly lower in kitchens as compared to those in cattle farms and hospital wards which were similar. Higher proportions of infected flies were obtained during summer whereas low proportions were obtained during winter. Conclusions. It is concluded that houseflies do harbor diarrheagenic pathogens, including Aeromonas especially during summer. The carried organisms are resistant to a number of antimicrobials at different levels. Thus, future plans aimed at stemming infections caused by these organisms should take flies into account. Control efforts of infections caused by this particular bacterium should therefore take into account Musca domestica.

  7. Leptogenesis, $\\mu - \\tau$ Symmetry and $\\theta_{13}$

    CERN Document Server

    Mohapatra, Rabindra N; Yu, H; Yu, Haibo

    2005-01-01

    We show that in theories where neutrino masses arise from type I seesaw formula with three right handed neutrinos and where large atmospheric mixing angle owes its origin to an approximate leptonic $\\mu-\\tau$ interchange symmetry, the primordial lepton asymmetry of the Universe, $\\epsilon_l$ can be expressed in a simple form in terms of low energy neutrino oscillation parameters as $\\epsilon_l = (a \\Delta m^2_\\odot+ b \\Delta m^2_A \\theta^2_{13})$, where $a$ and $b$ are parameters characterizing high scale physics and are each of order $\\leq 10^{-2} $ eV$^{-2}$. We also find that for the case of two right handed neutrinos, $\\epsilon_l \\propto \\theta^2_{13}$ as a result of which, the observed value of baryon to photon ratio implies a lower limit on $\\theta_{13}$. For specific choices of the CP phase $\\delta$ we find $\\theta_{13}$ is predicted to be between $0.10-0.15$.

  8. Expected reward modulates encoding-related theta activity before an event.

    Science.gov (United States)

    Gruber, Matthias J; Watrous, Andrew J; Ekstrom, Arne D; Ranganath, Charan; Otten, Leun J

    2013-01-01

    Oscillatory brain activity in the theta frequency range (4-8 Hz) before the onset of an event has been shown to affect the likelihood of successfully encoding the event into memory. Recent work has also indicated that frontal theta activity might be modulated by reward, but it is not clear how reward expectancy, anticipatory theta activity, and memory formation might be related. Here, we used scalp electroencephalography (EEG) to assess the relationship between these factors. EEG was recorded from healthy adults while they memorized a series of words. Each word was preceded by a cue that indicated whether a high or low monetary reward would be earned if the word was successfully remembered in a later recognition test. Frontal theta power between the presentation of the reward cue and the onset of a word was predictive of later memory for the word, but only in the high reward condition. No theta differences were observed before word onset following low reward cues. The magnitude of prestimulus encoding-related theta activity in the high reward condition was correlated with the number of high reward words that were later confidently recognized. These findings provide strong evidence for a link between reward expectancy, theta activity, and memory encoding. Theta activity before event onset seems to be especially important for the encoding of motivationally significant stimuli. One possibility is that dopaminergic activity during reward anticipation mediates frontal theta activity related to memory. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Theta function identities associated with Ramanujan's modular ...

    Indian Academy of Sciences (India)

    In Chapter 20 of his second notebook [6], Ramanujan recorded several theta function identities associated with modular equations of composite degree 15. These identities have previously been proved by Berndt in [3]. But he proved most of these theta function identities using modular equations. These identities can also ...

  10. Lee weight enumerators of self-dual codes and theta functions

    NARCIS (Netherlands)

    Asch, van A.G.; Martens, F.J.L.

    2008-01-01

    The theory of modular forms, in particular theta functions, and coding theory are in a remarkable way connected. The connection is established by defining a suitable lattice corresponding to the given code, and considering its theta function. First we define some special theta functions, and

  11. The enhancement by caffeine of the frequency of lethal dominant mutation induced by gamma radiation in oocytes of Musca domestica

    International Nuclear Information System (INIS)

    Targa, H.J.; Rogatko, A.

    1982-01-01

    The results obtained, when a new technique for feeding insects is employed, on the effects of caffeine of the radiation - induced breaks of oocyte chromatids of Musca domestica are presented. (M.A.) [pt

  12. Single-trial regression elucidates the role of prefrontal theta oscillations in response conflict

    Directory of Open Access Journals (Sweden)

    Michael X Cohen

    2011-02-01

    Full Text Available In most cognitive neuroscience experiments there are many behavioral and experimental dynamics, and many indices of brain activity, that vary from trial to trial. For example, in studies of response conflict, conflict is usually treated as a binary variable (i.e., response conflict exists or does not in any given trial, whereas some evidence and intuition suggests that conflict may vary in intensity from trial to trial. Here we demonstrate that single-trial multiple regression of time-frequency electrophysiological activity reveals neural mechanisms of cognitive control that are not apparent in cross-trial averages. We also introduce a novel extension to oscillation phase coherence and synchronization analyses, based on weighted phase modulation, that has advantages over standard coherence measures in terms of linking electrophysiological dynamics to trial-varying behavior and experimental variables. After replicating previous response conflict findings using trial-averaged data, we extend these findings using single trial analytic methods to provide novel evidence for the role of medial frontal-lateral prefrontal theta-band synchronization in conflict-induced response time dynamics, including a role for lateral prefrontal theta-band activity in biasing response times according to perceptual conflict. Given that these methods shed new light on the prefrontal mechanisms of response conflict, they are also likely to be useful for investigating other neurocognitive processes.

  13. Gravitational fragmentation caught in the act: the filamentary Musca molecular cloud

    Science.gov (United States)

    Kainulainen, J.; Hacar, A.; Alves, J.; Beuther, H.; Bouy, H.; Tafalla, M.

    2016-02-01

    Context. Filamentary structures are common in molecular clouds. Explaining how they fragment to dense cores is a missing step in understanding their role in star formation. Aims: We perform a case study of whether low-mass filaments are close to hydrostatic prior to their fragmentation, and whether their fragmentation agrees with gravitational fragmentation models. To accomplish this, we study the ~6.5 pc long Musca molecular cloud, which is an ideal candidate for a filament at an early stage of fragmentation. Methods: We employ dust extinction mapping, in conjunction with near-infrared JHKS-band data from the CTIO/NEWFIRM instrument, and 870 μm dust continuum emission data from the APEX/LABOCA instrument to estimate column densities in Musca. We use the data to identify fragments from the cloud and to determine the radial density distribution of its filamentary part. We compare the cloud's morphology with 13CO and C18O line emission observed with the APEX/SHeFI instrument. Results: The Musca cloud is pronouncedly fragmented at its ends, but harbors a remarkably well-defined, ~1.6 pc long filament in its center region. The line mass of the filament is 21-31 M⊙ pc-1 and the full width at half maximum (FWHM) 0.07 pc. The radial profile of the filament can be fitted with a Plummer profile, which has the power-index of 2.6 ± 11% and is flatter than that of an infinite hydrostatic filament. The profile can also be fitted with a hydrostatic cylinder truncated by external pressure. These models imply a central density of ~5-10 × 104 cm-3. The fragments in the cloud have a mean separation of ~0.4 pc, in agreement with gravitational fragmentation. These properties, together with the subsonic and velocity-coherent nature of the cloud, suggest a scenario in which an initially hydrostatic cloud is currently gravitationally fragmenting. The fragmentation started a few tenths of a Myr ago from the ends of the cloud, leaving its center still relatively nonfragmented

  14. Hippocampal theta activity in the acute cerveau isolé cat.

    Science.gov (United States)

    Gottesmann, C; Zernicki, B; Gandolfo, G

    1981-01-01

    In three cerveau isole cats, cortical and hippocampal EEG activity were recorded. In the cortical records, spindles alternated with low-voltage activity, whereas theta activity dominated in the hippocampus. The amount and frequency of theta were similar to those described previously for the pretrigeminal cat. In confirmation of previous results on rats, although cortical EEG activity differs in cerveau isole cat and pretrigeminal cat, both preparations show domination of theta activity in the hippocampus. It is concluded that the mesencephalic transection eliminates inhibitory effects from the lower brainstem on generators of the theta rhythm.

  15. Wound Myiasis Due to Musca domestica (Diptera: Muscidae in Persian Horned Viper, Pseudocerastes persicus (Squamata: Viperidae

    Directory of Open Access Journals (Sweden)

    R Dehghani

    2012-06-01

    Full Text Available A case of myiasis due to Musca domestica describes in Pseudocerastes persicus for the first time. The snake was found in Bari Karafs, Kashan, Iran, with a lesion on its body. Fourteen live larvae of M. domestica removed from its wound. This is the first report of a new larval habitat of M. domestica.

  16. Theta dynamics in rat: speed and acceleration across the Septotemporal axis.

    Directory of Open Access Journals (Sweden)

    Lauren L Long

    Full Text Available Theta (6-12 Hz rhythmicity in the local field potential (LFP reflects a clocking mechanism that brings physically isolated neurons together in time, allowing for the integration and segregation of distributed cell assemblies. Variation in the theta signal has been linked to locomotor speed, sensorimotor integration as well as cognitive processing. Previously, we have characterized the relationship between locomotor speed and theta power and how that relationship varies across the septotemporal (long axis of the hippocampus (HPC. The current study investigated the relationship between whole body acceleration, deceleration and theta indices at CA1 and dentate gyrus (DG sites along the septotemporal axis of the HPC in rats. Results indicate that whole body acceleration and deceleration predicts a significant amount of variability in the theta signal beyond variation in locomotor speed. Furthermore, deceleration was more predictive of variation in theta amplitude as compared to acceleration as rats traversed a linear track. Such findings highlight key variables that systematically predict the variability in the theta signal across the long axis of the HPC. A better understanding of the relative contribution of these quantifiable variables and their variation as a function of experience and environmental conditions should facilitate our understanding of the relationship between theta and sensorimotor/cognitive functions.

  17. A pedagogical introduction to theta functions

    International Nuclear Information System (INIS)

    Koh, I.G.; Shin, H.J.

    1988-01-01

    This paper reports on revolutions in physics that have been frequently accompanied by new developments in mathematics. In seventeenth century, Newton has initiated a program of describing celestial motion by classical mechanics. Integral and differential calculus was essential tool. Orbits of the moon and the earth are given by solving the differential equation of Newton's equation. Imagine a situation where one tries to solve such orbits without integral and differential calculus. Similar revolutions in understanding quantum gravity and in making deep connections between statistical and string physics are under progresses. One of indispensible tools are the theory of theta functions on Riemann surfaces. Since the literature of theta functions is mainly written by professional mathematician, physicists feel somewhat uneasy to begin to read a long chapters of lemmas and theorems, but it is now generally accepted that theta function is essential in understanding two-dimensional conformal field theory as the integral and differential calculus was indispensible in Newtonian mechanics

  18. Atmospheric, long baseline, and reactor neutrino data constraints on theta_{13}.

    Science.gov (United States)

    Roa, J E; Latimer, D C; Ernst, D J

    2009-08-07

    An atmospheric neutrino oscillation tool that uses full three-neutrino oscillation probabilities and a full three-neutrino treatment of the Mikheyev-Smirnov-Wolfenstein effect, together with an analysis of the K2K, MINOS, and CHOOZ data, is used to examine the bounds on theta_{13}. The recent, more finely binned, Super-K atmospheric data are employed. For L/E_{nu} greater, similar 10;{4} km/GeV, we previously found significant linear in theta_{13} terms. This analysis finds theta_{13} bounded from above by the atmospheric data while bounded from below by CHOOZ. The origin of this result arises from data in the previously mentioned very long baseline region; here, matter effects conspire with terms linear in theta_{13} to produce asymmetric bounds on theta_{13}. Assuming CP conservation, we find theta_{13} = -0.07_{-0.11};{+0.18} (90% C.L.).

  19. Effects of relative humidity, temperature, and population density on production of cuticular hydrocarbons in housefly Musca domestica L.

    NARCIS (Netherlands)

    Noorman, N; Den Otter, CJ

    The production of cuticular hydrocarbons by both males and females of Musca domestica L. under very wet conditions (90% relative humidity) compared to the production at 50 and 20% relative humidity is delayed up to at least 3 days after emergence from the pupae. Eight days after emergence, however,

  20. Movement-related theta rhythm in humans: coordinating self-directed hippocampal learning.

    Directory of Open Access Journals (Sweden)

    Raphael Kaplan

    Full Text Available The hippocampus is crucial for episodic or declarative memory and the theta rhythm has been implicated in mnemonic processing, but the functional contribution of theta to memory remains the subject of intense speculation. Recent evidence suggests that the hippocampus might function as a network hub for volitional learning. In contrast to human experiments, electrophysiological recordings in the hippocampus of behaving rodents are dominated by theta oscillations reflecting volitional movement, which has been linked to spatial exploration and encoding. This literature makes the surprising cross-species prediction that the human hippocampal theta rhythm supports memory by coordinating exploratory movements in the service of self-directed learning. We examined the links between theta, spatial exploration, and memory encoding by designing an interactive human spatial navigation paradigm combined with multimodal neuroimaging. We used both non-invasive whole-head Magnetoencephalography (MEG to look at theta oscillations and Functional Magnetic Resonance Imaging (fMRI to look at brain regions associated with volitional movement and learning. We found that theta power increases during the self-initiation of virtual movement, additionally correlating with subsequent memory performance and environmental familiarity. Performance-related hippocampal theta increases were observed during a static pre-navigation retrieval phase, where planning for subsequent navigation occurred. Furthermore, periods of the task showing movement-related theta increases showed decreased fMRI activity in the parahippocampus and increased activity in the hippocampus and other brain regions that strikingly overlap with the previously observed volitional learning network (the reverse pattern was seen for stationary periods. These fMRI changes also correlated with participant's performance. Our findings suggest that the human hippocampal theta rhythm supports memory by coordinating

  1. A eficiência de formação estelar em Musca

    Science.gov (United States)

    Hickel, G. R.; Vilas-Boas, J. W. S.; Roberto, A. J.., Jr.; Khan, R. P.

    2003-08-01

    Apresentamos os resultados de um survey no infravermelho próximo (bandas J e H), executado no Laboratório Nacional de Astrofísica, na direção da nuvem escura em forma de filamento de Musca (observamos ao longo de todo o filamento, além de todas as fontes pontuais IRAS e/ou fontes ROSAT brilhantes a uma distância de 2o da nuvem). Nosso objetivo é determinar a eficiência de formação estelar para esta nuvem escura (massa de estrelas formadas/massa da nuvem), procurando por objetos estelares jovens de pequena massa no seu interior e/ou evoluídos o suficiente para estarem afastados do local de nascimento, mas ainda mostrando características de objetos pré-seqüência principal como emissão de raios-X e excesso de emissão no infravermelho próximo. Este survey não estabeleceu nenhum viés na seleção de fontes pontuais IRAS ou fontes ROSAT, uma vez que a imensa maioria das fontes pontuais IRAS nesta região têm qualidade de fluxo ruim. Os candidatos a objetos estelares jovens foram selecionados pelo excesso no índice de cor (J-H), descontados os efeitos da extinção interestelar na linha de visada, determinada através da emissão estendida no infravermelho distante (IRAS). Estimativas de massa foram feitas para estes candidatos, através da relação massa-luminosidade, para calcular a eficiência de formação estelar de Musca.

  2. Enhancing early consolidation of human episodic memory by theta EEG neurofeedback.

    Science.gov (United States)

    Rozengurt, Roman; Shtoots, Limor; Sheriff, Aviv; Sadka, Ofir; Levy, Daniel A

    2017-11-01

    Consolidation of newly formed memories is readily disrupted, but can it be enhanced? Given the prominent role of hippocampal theta oscillations in memory formation and retrieval, we hypothesized that upregulating theta power during early stages of consolidation might benefit memory stability and persistence. We used EEG neurofeedback to enable participants to selectively increase theta power in their EEG spectra following episodic memory encoding, while other participants engaged in low beta-focused neurofeedback or passively viewed a neutral nature movie. Free recall assessments immediately following the interventions, 24h later and 7d later all indicated benefit to memory of theta neurofeedback, relative to low beta neurofeedback or passive movie-viewing control conditions. The degree of benefit to memory was correlated with the extent of theta power modulation, but not with other spectral changes. Theta enhancement may provide optimal conditions for stabilization of new hippocampus-dependent memories. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Engineering prototypes for theta-pinch devices

    International Nuclear Information System (INIS)

    Hansborough, L.D.; Hammer, C.F.; Hanks, K.W.; McDonald, T.E.; Nunnally, W.C.

    1975-01-01

    Past, present, and future engineering prototypes for theta-pinch plasma-physics devices at Los Alamos Scientific Laboratory are discussed. Engineering prototypes are designed to test and evaluate all components under system conditions expected on actual plasma-physics experimental devices. The importance of engineering prototype development increases as the size and complexity of the plasma-physics device increases. Past experiences with the Scyllac prototype and the Staged Theta-Pinch prototype are discussed and evaluated. The design of the proposed Staged Scyllac prototype and the Large Staged Scyllac implosion prototype assembly are discussed

  4. Theta variation and spatiotemporal scaling along the septotemporal axis of the hippocampus

    Directory of Open Access Journals (Sweden)

    Lauren L Long

    2015-03-01

    Full Text Available Hippocampal theta has been related to locomotor speed, attention, anxiety, sensorimotor integration and memory among other emergent phenomena. One difficulty in understanding the function of theta is that the hippocampus (HPC modulates voluntary behavior at the same time that it processes sensory input. Both functions are correlated with characteristic changes in theta indices. The current review highlights a series of studies examining theta local field potential (LFP signals across the septotemporal or longitudinal axis of the HPC. While the theta signal is coherent throughout the entirety of the HPC, the amplitude, but not the frequency, of theta varies significantly across its three-dimensional expanse. We suggest that the theta signal offers a rich vein of information about how distributed neuronal ensembles support emergent function. Further, we speculate that emergent function across the long axis varies with respect to spatiotemporal scale. Thus, septal hippocampus processes details of the proximal spatiotemporal environment while more temporal aspects process larger spaces and wider time-scales. The degree to which emergent functions are supported by the synchronization of theta across the septotemporal axis is an open question. Our working model is that theta synchrony serves to bind ensembles representing varying resolutions of spatiotemporal information at interdependent septotemporal areas of the HPC. Such synchrony and cooperative interactions along the septotemporal axis likely support memory formation and subsequent consolidation and retrieval.

  5. Genome of the house fly, Musca domestica L., a global vector of diseases with adaptations to a septic environment

    NARCIS (Netherlands)

    Scott, Jeffrey G; Warren, Wesley C; Beukeboom, Leo W; Bopp, Daniel; Clark, Andrew G; Giers, Sarah D; Hediger, Monika; Jones, Andrew K; Kasai, Shinji; Leichter, Cheryl A; Li, Ming; Meisel, Richard P; Minx, Patrick; Murphy, Terence D; Nelson, David R; Reid, William R; Rinkevich, Frank D; Robertson, Hugh M; Sackton, Timothy B; Sattelle, David B; Thibaud-Nissen, Francoise; Tomlinson, Chad; van de Zande, Louis; Walden, Kimberly; Wilson, Richard K; Liu, Nannan

    2014-01-01

    BACKGROUND: Adult house flies, Musca domestica L., are mechanical vectors of more than 100 devastating diseases that have severe consequences for human and animal health. House fly larvae play a vital role as decomposers of animal wastes, and thus live in intimate association with many animal

  6. Independent delta/theta rhythms in the human hippocampus and entorhinal cortex

    Directory of Open Access Journals (Sweden)

    Florian Mormann

    2008-05-01

    Full Text Available Theta oscillations in the medial temporal lobe (MTL of mammals are involved in various functions such as spatial navigation, sensorimotor integration, and cognitive processing. While the theta rhythm was originally assumed to originate in the medial septum, more recent studies suggest autonomous theta generation in the MTL. Although coherence between entorhinal and hippocampal theta activity has been found to influence memory formation, it remains unclear whether these two structures can generate theta independently. In this study we analyzed intracranial electroencephalographic (EEG recordings from 22 patients with unilateral hippocampal sclerosis undergoing presurgical evaluation prior to resection of the epileptic focus. Using a wavelet-based, frequency-band-specific measure of phase synchronization, we quantified synchrony between 10 different recording sites along the longitudinal axis of the hippocampal formation in the non-epileptic brain hemisphere. We compared EEG synchrony between adjacent recording sites (i within the entorhinal cortex, (ii within the hippocampus, and (iii between the hippocampus and entorhinal cortex. We observed a significant interregional gap in synchrony for the delta and theta band, indicating the existence of independent delta/theta rhythms in different subregions of the human MTL. The interaction of these rhythms could represent the temporal basis for the information processing required for mnemonic encoding and retrieval.

  7. Effect of four commercial fungal formulations on mortality and sporulation of house flies (Musca domestica) and stable flies (Stomoxys calcitrans)

    Science.gov (United States)

    House flies (Musca domestica L.) and stable flies (Stomoxys calcitrans (L.)) (Diptera: Muscidae) are major pests of livestock. Biological control is an important tool in an integrated control framework. Increased mortality in filth flies has been documented with entomopathogenic fungi, and several s...

  8. A computational study on altered theta-gamma coupling during learning and phase coding.

    Directory of Open Access Journals (Sweden)

    Xuejuan Zhang

    Full Text Available There is considerable interest in the role of coupling between theta and gamma oscillations in the brain in the context of learning and memory. Here we have used a neural network model which is capable of producing coupling of theta phase to gamma amplitude firstly to explore its ability to reproduce reported learning changes and secondly to memory-span and phase coding effects. The spiking neural network incorporates two kinetically different GABA(A receptor-mediated currents to generate both theta and gamma rhythms and we have found that by selective alteration of both NMDA receptors and GABA(A,slow receptors it can reproduce learning-related changes in the strength of coupling between theta and gamma either with or without coincident changes in theta amplitude. When the model was used to explore the relationship between theta and gamma oscillations, working memory capacity and phase coding it showed that the potential storage capacity of short term memories, in terms of nested gamma-subcycles, coincides with the maximal theta power. Increasing theta power is also related to the precision of theta phase which functions as a potential timing clock for neuronal firing in the cortex or hippocampus.

  9. Completely X-symmetric S-matrices corresponding to theta functions

    International Nuclear Information System (INIS)

    Chudnovsky, D.V.

    1981-01-01

    We consider the realization of the classical Weyl commutation relations using THETA-functions. The representations of the Heisenberg group enable us to realize completely symmetric factorized S-matrices in terms of THETA-functions corresponding to the torsion subgroup of an abelian variety. (orig.)

  10. Theta oscillations locked to intended actions rhythmically modulate perception.

    Science.gov (United States)

    Tomassini, Alice; Ambrogioni, Luca; Medendorp, W Pieter; Maris, Eric

    2017-07-07

    Ongoing brain oscillations are known to influence perception, and to be reset by exogenous stimulations. Voluntary action is also accompanied by prominent rhythmic activity, and recent behavioral evidence suggests that this might be coupled with perception. Here, we reveal the neurophysiological underpinnings of this sensorimotor coupling in humans. We link the trial-by-trial dynamics of EEG oscillatory activity during movement preparation to the corresponding dynamics in perception, for two unrelated visual and motor tasks. The phase of theta oscillations (~4 Hz) predicts perceptual performance, even >1 s before movement. Moreover, theta oscillations are phase-locked to the onset of the movement. Remarkably, the alignment of theta phase and its perceptual relevance unfold with similar non-monotonic profiles, suggesting their relatedness. The present work shows that perception and movement initiation are automatically synchronized since the early stages of motor planning through neuronal oscillatory activity in the theta range.

  11. Cubic metaplectic forms and theta functions

    CERN Document Server

    Proskurin, Nikolai

    1998-01-01

    The book is an introduction to the theory of cubic metaplectic forms on the 3-dimensional hyperbolic space and the author's research on cubic metaplectic forms on special linear and symplectic groups of rank 2. The topics include: Kubota and Bass-Milnor-Serre homomorphisms, cubic metaplectic Eisenstein series, cubic theta functions, Whittaker functions. A special method is developed and applied to find Fourier coefficients of the Eisenstein series and cubic theta functions. The book is intended for readers, with beginning graduate-level background, interested in further research in the theory of metaplectic forms and in possible applications.

  12. Pre-stimulus thalamic theta power predicts human memory formation.

    Science.gov (United States)

    Sweeney-Reed, Catherine M; Zaehle, Tino; Voges, Jürgen; Schmitt, Friedhelm C; Buentjen, Lars; Kopitzki, Klaus; Richardson-Klavehn, Alan; Hinrichs, Hermann; Heinze, Hans-Jochen; Knight, Robert T; Rugg, Michael D

    2016-09-01

    Pre-stimulus theta (4-8Hz) power in the hippocampus and neocortex predicts whether a memory for a subsequent event will be formed. Anatomical studies reveal thalamus-hippocampal connectivity, and lesion, neuroimaging, and electrophysiological studies show that memory processing involves the dorsomedial (DMTN) and anterior thalamic nuclei (ATN). The small size and deep location of these nuclei have limited real-time study of their activity, however, and it is unknown whether pre-stimulus theta power predictive of successful memory formation is also found in these subcortical structures. We recorded human electrophysiological data from the DMTN and ATN of 7 patients receiving deep brain stimulation for refractory epilepsy. We found that greater pre-stimulus theta power in the right DMTN was associated with successful memory encoding, predicting both behavioral outcome and post-stimulus correlates of successful memory formation. In particular, significant correlations were observed between right DMTN theta power and both frontal theta and right ATN gamma (32-50Hz) phase alignment, and frontal-ATN theta-gamma cross-frequency coupling. We draw the following primary conclusions. Our results provide direct electrophysiological evidence in humans of a role for the DMTN as well as the ATN in memory formation. Furthermore, prediction of subsequent memory performance by pre-stimulus thalamic oscillations provides evidence that post-stimulus differences in thalamic activity that index successful and unsuccessful encoding reflect brain processes specifically underpinning memory formation. Finally, the findings broaden the understanding of brain states that facilitate memory encoding to include subcortical as well as cortical structures. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Chasing theta-13 with the Double Chooz experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lasserre, Thierry [CEA/DSM/IRFU/SPP, Gif-sur-Yvette (France)

    2009-07-01

    Neutrino oscillation physics is entering a precision measurement area. The smallness of the theta-13 neutrino mixing angle is still enigmatic and should be resolved. Double Chooz will use two identical detectors near the Chooz nuclear power station to search for a non vanishing theta-13, and hopefully open the way to experiments aspiring to discover CP violation in the leptonic sector.

  14. Some theorems on the explicit evaluation of Ramanujan's theta-functions

    Directory of Open Access Journals (Sweden)

    Nayandeep Deka Baruah

    2004-01-01

    Full Text Available Bruce C. Berndt et al. and Soon-Yi Kang have proved many of Ramanujan's formulas for the explicit evaluation of the Rogers-Ramanujan continued fraction and theta-functions in terms of Weber-Ramanujan class invariants. In this note, we give alternative proofs of some of these identities of theta-functions recorded by Ramanujan in his notebooks and deduce some formulas for the explicit evaluation of his theta-functions in terms of Weber-Ramanujan class invariants.

  15. Fluctuating inhibitory inputs promote reliable spiking at theta frequencies in hippocampal interneurons

    Directory of Open Access Journals (Sweden)

    Duluxan eSritharan

    2012-05-01

    Full Text Available Theta frequency (4-12 Hz rhythms in the hippocampus play important roles in learning and memory. CA1 interneurons located at the stratum lacunosum-moleculare and radiatum junction (LM/RAD are thought to contribute to hippocampal theta population activities by rhythmically pacing pyramidal cells with inhibitory postsynaptic potentials. This implies that LM/RAD cells need to fire reliably at theta frequencies in vivo. To determine whether this could occur, we use biophysically-based LM/RAD model cells and apply different cholinergic and synaptic inputs to simulate in vivo-like network environments. We assess spike reliabilities and spiking frequencies, identifying biophysical properties and network conditions that best promote reliable theta spiking. We find that synaptic background activities that feature large inhibitory, but not excitatory, fluctuations are essential. This suggests that strong inhibitory input to these cells is vital for them to be able to contribute to population theta activities. Furthermore, we find that Type I-like oscillator models produced by augmented persistent sodium currents (INap or diminished A type potassium currents (IA enhance reliable spiking at lower theta frequencies. These Type I-like models are also the most responsive to large inhibitory fluctuations and can fire more reliably under such conditions. In previous work, we showed that INap and IA are largely responsible for establishing LM/RAD cells’ subthreshold activities. Taken together with this study, we see that while both these currents are important for subthreshold theta fluctuations and reliable theta spiking, they contribute in different ways – INap to reliable theta spiking and subthreshold activity generation, and IA to subthreshold activities at theta frequencies. This suggests that linking subthreshold and suprathreshold activities should be done with consideration of both in vivo contexts and biophysical specifics.

  16. Oscillatory frontal theta responses are increased upon bisensory stimulation.

    Science.gov (United States)

    Sakowitz, O W; Schürmann, M; Başar, E

    2000-05-01

    To investigate the functional correlation of oscillatory EEG components with the interaction of sensory modalities following simultaneous audio-visual stimulation. In an experimental study (15 subjects) we compared auditory evoked potentials (AEPs) and visual evoked potentials (VEPs) to bimodal evoked potentials (BEPs; simultaneous auditory and visual stimulation). BEPs were assumed to be brain responses to complex stimuli as a marker for intermodal associative functioning. Frequency domain analysis of these EPs showed marked theta-range components in response to bimodal stimulation. These theta components could not be explained by linear addition of the unimodal responses in the time domain. Considering topography the increased theta-response showed a remarkable frontality in proximity to multimodal association cortices. Referring to methodology we try to demonstrate that, even if various behavioral correlates of brain oscillations exist, common patterns can be extracted by means of a systems-theoretical approach. Serving as an example of functionally relevant brain oscillations, theta responses could be interpreted as an indicator of associative information processing.

  17. Adaptive [theta]-methods for pricing American options

    Science.gov (United States)

    Khaliq, Abdul Q. M.; Voss, David A.; Kazmi, Kamran

    2008-12-01

    We develop adaptive [theta]-methods for solving the Black-Scholes PDE for American options. By adding a small, continuous term, the Black-Scholes PDE becomes an advection-diffusion-reaction equation on a fixed spatial domain. Standard implementation of [theta]-methods would require a Newton-type iterative procedure at each time step thereby increasing the computational complexity of the methods. Our linearly implicit approach avoids such complications. We establish a general framework under which [theta]-methods satisfy a discrete version of the positivity constraint characteristic of American options, and numerically demonstrate the sensitivity of the constraint. The positivity results are established for the single-asset and independent two-asset models. In addition, we have incorporated and analyzed an adaptive time-step control strategy to increase the computational efficiency. Numerical experiments are presented for one- and two-asset American options, using adaptive exponential splitting for two-asset problems. The approach is compared with an iterative solution of the two-asset problem in terms of computational efficiency.

  18. Eisenstein Series Identities Involving the Borweins' Cubic Theta Functions

    Directory of Open Access Journals (Sweden)

    Ernest X. W. Xia

    2012-01-01

    Full Text Available Based on the theories of Ramanujan's elliptic functions and the (p, k-parametrization of theta functions due to Alaca et al. (2006, 2007, 2006 we derive certain Eisenstein series identities involving the Borweins' cubic theta functions with the help of the computer. Some of these identities were proved by Liu based on the fundamental theory of elliptic functions and some of them may be new. One side of each identity involves Eisenstein series, the other products of the Borweins' cubic theta functions. As applications, we evaluate some convolution sums. These evaluations are different from the formulas given by Alaca et al.

  19. Torus C-I field reversed theta-pinch at UNICAMP

    International Nuclear Information System (INIS)

    Machida, M.; Collares, M.P.; Honda, R.Y.; Sakanaka, P.H.; Scheid, V.H.B.

    1984-01-01

    The influence of multipole fields (octopole and quadrupole) on supressing the n=2 rotational instability, field reconnection, particle loss effects is studied, and the viability of transforming the theta-pinch from Campinas, Brazil (100Kv, 55Kj) to the field reversed theta-pinch with plasma translation program is analyzed. (E.G.) [pt

  20. Stage theta pinch experiments

    International Nuclear Information System (INIS)

    Linford, R.K.; Downing, J.N.; Gribble, R.F.; Jacobson, A.R.; Platts, D.A.; Thomas, K.S.

    1975-01-01

    The Staged Theta Pinch program is designed to study the technological and physics problems associated with producing fat plasmas and separating the implosion heating from the adiabatic compression. Several methods of implosion heating are discussed. Circuit diagrams and theoretical magnetic field behavior are described for the STP and resonant heating experiments. (MOW)

  1. Riemann-Theta Boltzmann Machine arXiv

    CERN Document Server

    Krefl, Daniel; Haghighat, Babak; Kahlen, Jens

    A general Boltzmann machine with continuous visible and discrete integer valued hidden states is introduced. Under mild assumptions about the connection matrices, the probability density function of the visible units can be solved for analytically, yielding a novel parametric density function involving a ratio of Riemann-Theta functions. The conditional expectation of a hidden state for given visible states can also be calculated analytically, yielding a derivative of the logarithmic Riemann-Theta function. The conditional expectation can be used as activation function in a feedforward neural network, thereby increasing the modelling capacity of the network. Both the Boltzmann machine and the derived feedforward neural network can be successfully trained via standard gradient- and non-gradient-based optimization techniques.

  2. What is the functional relevance of prefrontal cortex entrainment to hippocampal theta rhythms?

    Directory of Open Access Journals (Sweden)

    James Michael Hyman

    2011-03-01

    Full Text Available There has been considerable interest in the importance of oscillations in the brain and in how these oscillations relate to the firing of single neurons. Recently a number of studies have shown that the spiking of individual neurons in the medial prefrontal cortex (mPFC become entrained to the hippocampal (HPC theta rhythm. We recently showed that theta-entrained mPFC cells lost theta-entrainment specifically on error trials even though the firing rates of these cells did not change (Hyman et al., 2010. This implied that the level of HPC theta-entrainment of mPFC units was more predictive of trial outcome than differences in firing rates and that there is more information encoded by the mPFC on working memory tasks than can be accounted for by a simple rate code. Nevertheless, the functional meaning of mPFC entrainment to HPC theta remains a mystery. It is also unclear as to whether there are any differences in the nature of the information encoded by theta-entrained and non-entrained mPFC cells. In this review we discuss mPFC entrainment to HPC theta within the context of previous results as well as provide a more detailed analysis of the Hyman et al. (2010 data set. This re-analysis revealed that theta-entrained mPFC cells selectively encoded a variety of task relevant behaviors and stimuli while never theta-entrained mPFC cells were most strongly attuned to errors or the lack of expected rewards. In fact, these error responsive neurons were responsible for the error representations exhibited by the entire ensemble of mPFC neurons. A theta reset was also detected in the post-error period. While it is becoming increasingly evident that mPFC neurons exhibit correlates to virtually all cues and behaviors, perhaps phase-locking directs attention to the task-relevant representations required to solve a spatially based working memory task while the loss of theta-entrainment at the start of error trials may represent a shift of attention away from

  3. The Effects of Temperature and Innate Immunity on Transmission of Campylobacter jejuni (Campylobacterales: Campylobacteraceae) Between Life Stages of Musca domestica (Diptera: Muscidae)

    DEFF Research Database (Denmark)

    Bahrndorff, Simon; Gill, C.; Lowenberger, C.

    2014-01-01

    The house fly (Musca domestica L.) is a well-established vector of human pathogens, including Campylobacter spp., which can cause infection of broiler chicken flocks, and through contaminated broiler meat can cause outbreaks of campylobacteriosis in humans. We investigated whether Campylobacter j...

  4. Phenology of Spalangia endius Walker (Hymenoptera, Pteromalidae in pupae of Musca domestica Linnaeus (Diptera, Muscidae under laboratory conditions Fenologia de Spalangia endius Walker (Hymenoptera, Pteromalidae em pupas de Musca domestica Linnaeus (Diptera, Muscidae em condições de laboratório

    Directory of Open Access Journals (Sweden)

    Dani Furtado de Araújo

    2012-12-01

    Full Text Available This work describes the phenology of Spalangia endius Walker in pupae of Musca domestica Linnaeus under laboratory conditions. In order to understand the developmental cycle of Spalangia endius under laboratory conditions, 360 Musca domestica pupae aged from 24 to 48 hours were exposed to 15 S. endius pairs for a period of 24 hours at 26 ± 2ºC. These pupae were kept in a BOD incubator at the same temperature, with a relative humidity of Objetivando conhecer o ciclo de desenvolvimento de Spalangia endius sob condições de laboratório, 360 pupas de Musca domestica com idade de 24 a 48 horas foram expostas a 15 casais de S. endius por um período de 48 horas a 26 ± 2ºC. Estas pupas foram mantidas em BOD. Com mesma temperatura, umidade relativa <70% e com fotofase de 12 horas, onde diariamente dissecava-se 15 espécimes para avaliar o estágio e tempo de desenvolvimento do himenóptero. A fenologia permite concluir que S. endius apresenta um ciclo de desenvolvimento de 19 dias, cujo período de incubação foi de 24 horas, o desenvolvimento de larvas de S. endius ocorreu nos oito dias subsequentes nos quais uma série de alterações morfológicas foi observada. O estágio de pré-pupa deu-se no décimo dia onde cessa a movimentação e inicia a eliminação de mecônio. O estágio pupal ocorreu do décimo primeiro dia ao décimo nono, momento da emergência dos primeiros machos, já as fêmeas iniciaram a emergência aproximadamente 24 horas após. Estes resultados permitem avaliar aspectos da bionomia pormenorizada do desenvolvimento de S. endius para armazenar e programar a produção deste parasitóide, otimizando sua utilização como agente de controle biológico.

  5. Survival and Movement of Insect Parasitic Nematodes in Poultry Manure and Their Infectivity Against Musca domestica

    OpenAIRE

    Georgis, Ramon; Mullens, Bradley A.; Meyer, Jeffery A.

    1987-01-01

    Survival, infectivity, and movement of three insect parasitic nematodes (Steinernema feltiae All strain, S. bibionis SN strain, and Heterorhabditis heliothidis NC strain) in poultry manure were tested under laboratory conditions. The majority (70-100%) of the nematodes died within 18 hours after exposure to the manure. Nematodes exposed to manure slurry for 6 hours killed at least 95% of the house fly larvae, Musca domestica, but nematodes exposed for 12 hours achieved less than 40% larval mo...

  6. The Effects of Sex-Ratio and Density on Locomotor Activity in the House Fly, Musca domestica

    OpenAIRE

    Bahrndorff, Simon; Kjærsgaard, Anders; Pertoldi, Cino; Loeschcke, Volker; Schou, Toke M.; Skovgård, Henrik; Hald, Birthe

    2012-01-01

    Although locomotor activity is involved in almost all behavioral traits, there is a lack of knowledge on what factors affect it. This study examined the effects of sex-ratio and density on the circadian rhythm of locomotor activity of adult Musca domestica L. (Diptera: Muscidae) using an infra-red light system. Sex-ratio significantly affected locomotor activity, increasing with the percentage of males in the vials. In accordance with other studies, males were more active than females, but th...

  7. Recent developments in linear theta-pinch research: experiment and theory

    International Nuclear Information System (INIS)

    McKenna, K.F.; Bartsch, R.R.; Commisso, R.J.

    1978-01-01

    High energy plasmas offusion interest can be generated in linear theta pinches. However, end losses present a fundamental limitation on the plasma containment time. This paper discusses recent progress in end-loss and end-stoppering experiments and in the theoretical understanding of linear theta-pinch physics

  8. Double-Chooz: a search for {theta}{sub 13}

    Energy Technology Data Exchange (ETDEWEB)

    Lasserre, Th. [DSM/DAPNIA/SPP, CEA/Saclay, 91191 Gif-sur-Yvette (France)

    2005-12-15

    The Double-Chooz experiment goal is to search for a non-vanishing value of the {theta}{sub 13} neutrino mixing angle. This is the last step to accomplish prior moving towards a new era of precision measurements in the lepton sector. The current best constraint on the third mixing angle comes from the CHOOZ reactor neutrino experiment sin{sup 2}(2{theta}{sub 13})<0.2 (90% C.L., {delta}m{sub atm}{sup 2}=2.0eV{sup 2}). Double-Chooz will explore the range of sin{sup 2}(2{theta}{sub 13}) from 0.2 to 0.03-0.02, within three years of data taking. The improvement of the CHOOZ result requires an increase in the statistics, a reduction of the systematic error below one percent, and a careful control of the backgrounds. Therefore, Double-Chooz will use two identical detectors, one at 150 m and another at 1.05 km distance from the Chooz nuclear cores. In addition, we will use the near detector as a ''state of the art'' prototype to investigate the potential of neutrinos for monitoring the civil nuclear power plants. The plan is to start operation with two detectors in 2008, and to reach a sensitivity sin{sup 2}(2{theta}{sub 13}) of 0.05 in 2009, and 0.03-0.02 in 2011.

  9. Energy transfer efficiency measurements in a theta-pinch

    International Nuclear Information System (INIS)

    Cavalcanti, G.H.; Luna, F.R.T.; Trigueiros, A.G.

    1993-01-01

    An increase in energy transfer efficiency of the capacitor bank to the plasma was obtained when the electrical system of a theta-pinch was changed so that the ratio of total inductance to coil inductance was switched of 1/6 to 1/2. A further increase about 20% was obtained for 16/1 ratio. The measurements were made through the current discharge decay, and the spectral analysis of the emitted light from theta-pinch shows a correspondent efficiency increase. (author)

  10. Effects of Persea americana Mill. seed extracts on the postembryonic development of Musca domestica (Diptera: Muscoide

    Directory of Open Access Journals (Sweden)

    Silvia del C. Molina Bertrán

    2018-04-01

    Full Text Available Context: The synthetic insecticides used to control Diptera are harmful to the environment and humans. Extracts and compounds from plants are a more sustainable source for the development of bio-insecticides. Aims: To evaluate the efficacy of a hydroalcoholic extract of Persea americana Mill seeds as an alternative control of the species Musca domestica. Methods: The extracts were obtained by two methods, the Shaker (S and the Soxhlet extraction (SE method, using 94% ethanol as the solvent. Also, the qualitative chemical composition was determined by phytochemical screening. The effect of the two extracts on the post-embryonic development of the fly as well as the adulticidal effect was evaluated. Results: Phytochemical analysis revealed the presence of metabolites such as alkaloids, coumarins, tannins, flavonoids, sugars and amino acids. The influence on the post-embryonic development of M. domestica was demonstrated, especially on the viability of larvae and neolarvae to adults; however, the effect on the weight and duration of each period was low. The adulticidal effects of the extracts were determined by the lethal concentration 50(LC50 of 2.910 mg/100 mL and 3.944 mg/100 mL for the S and SE extracts, respectively. Conclusions: Both extracts showed their insecticidal effects against Musca domestica, but the extract elaborated by S method showed greater influence diminishing viability and better adulticidal effect.

  11. Hippocampal Theta-Gamma Coupling Reflects State-Dependent Information Processing in Decision Making.

    Science.gov (United States)

    Amemiya, Seiichiro; Redish, A David

    2018-03-20

    During decision making, hippocampal activity encodes information sometimes about present and sometimes about potential future plans. The mechanisms underlying this transition remain unknown. Building on the evidence that gamma oscillations at different frequencies (low gamma [LG], 30-55 Hz; high gamma [HG], 60-90 Hz; and epsilon, 100-140 Hz) reflect inputs from different circuits, we identified how changes in those frequencies reflect different information-processing states. Using a unique noradrenergic manipulation by clonidine, which shifted both neural representations and gamma states, we found that future representations depended on gamma components. These changes were identifiable on each cycle of theta as asymmetries in the theta cycle, which arose from changes within the ratio of LG and HG power and the underlying phases of those gamma rhythms within the theta cycle. These changes in asymmetry of the theta cycle reflected changes in representations of present and future on each theta cycle. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  12. Theta series, wall-crossing and quantum dilogarithm identities

    CERN Document Server

    Alexandrov, Sergei

    2016-01-01

    Motivated by mathematical structures which arise in string vacua and gauge theories with N=2 supersymmetry, we study the properties of certain generalized theta series which appear as Fourier coefficients of functions on a twisted torus. In Calabi-Yau string vacua, such theta series encode instanton corrections from $k$ Neveu-Schwarz five-branes. The theta series are determined by vector-valued wave-functions, and in this work we obtain the transformation of these wave-functions induced by Kontsevich-Soibelman symplectomorphisms. This effectively provides a quantum version of these transformations, where the quantization parameter is inversely proportional to the five-brane charge $k$. Consistency with wall-crossing implies a new five-term relation for Faddeev's quantum dilogarithm $\\Phi_b$ at $b=1$, which we prove. By allowing the torus to be non-commutative, we obtain a more general five-term relation valid for arbitrary $b$ and $k$, which may be relevant for the physics of five-branes at finite chemical po...

  13. Production of $\\Theta^{+}$ (1540) and $\\Xi$ pentaquark states in proton- proton interactions

    CERN Document Server

    Bleicher, M; Liu, F M; Pierog, T; Werner, K; 10.1016/j.physletb.2004.05.010

    2004-01-01

    The production of strange pentaquark states (e.g., Theta baryons and Xi /sup --/states) in hadronic interactions within a Gribov-Regge approach is explored. In this approach the Theta /sup +/(1540) and the Xi are produced by disintegration of remnants formed by the exchange of pomerons between the two protons. We predict the rapidity and transverse momentum distributions as well as the 4 pi multiplicity of the Theta /sup +/, Xi /sup --/ , Xi /sup -/, Xi /sup 0/ and Xi /sup +/ for square root s=17 GeV (SPS) and 200 GeV (RHIC). For both energies more than 10/sup -3/ Theta /sup +/ and more than 10 /sup -5/ Xi per pp event should be observed by the present experiments.

  14. Theta Neurofeedback Effects on Motor Memory Consolidation and Performance Accuracy: An Apparent Paradox?

    Science.gov (United States)

    Reiner, Miriam; Lev, Dror D; Rosen, Amit

    2018-05-15

    Previous studies have shown that theta neurofeedback enhances motor memory consolidation on an easy-to-learn finger-tapping task. However, the simplicity of the finger-tapping task precludes evaluating the putative effects of elevated theta on performance accuracy. Mastering a motor sequence is classically assumed to entail faster performance with fewer errors. The speed-accuracy tradeoff (SAT) principle states that as action speed increases, motor performance accuracy decreases. The current study investigated whether theta neurofeedback could improve both performance speed and performance accuracy, or would only enhance performance speed at the cost of reduced accuracy. A more complex task was used to study the effects of parietal elevated theta on 45 healthy volunteers The findings confirmed previous results on the effects of theta neurofeedback on memory consolidation. In contrast to the two control groups, in the theta-neurofeedback group the speed-accuracy tradeoff was reversed. The speed-accuracy tradeoff patterns only stabilized after a night's sleep implying enhancement in terms of both speed and accuracy. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  15. Simplified scaling model for the THETA-pinch

    Science.gov (United States)

    Ewing, K. J.; Thomson, D. B.

    1982-02-01

    A simple ID scaing model for the fast Theta pinch was developed and written as a code that would be flexible, inexpensive in computer time, and readily available for use with the Los Alamos explosive-driven high magnetic field program. The simplified model uses three successive separate stages: (1) a snowplow-like radial implosion, (2) an idealized resistive annihilation of reverse bias field, and (3) an adiabatic compression stage of a Beta = 1 plasma for which ideal pressure balance is assumed to hold. The code uses one adjustable fitting constant whose value was first determined by comparison with results from the Los Alamos Scylla III, Scyllacita, and Scylla IA Theta pinches.

  16. The Effects of Theta and Gamma tACS on Working Memory and Electrophysiology

    Directory of Open Access Journals (Sweden)

    Anja Pahor

    2018-01-01

    Full Text Available A single blind sham-controlled study was conducted to explore the effects of theta and gamma transcranial alternating current stimulation (tACS on offline performance on working memory tasks. In order to systematically investigate how specific parameters of tACS affect working memory, we manipulated the frequency of stimulation (theta frequency vs. gamma frequency, the type of task (n-back vs. change detection task and the content of the tasks (verbal vs. figural stimuli. A repeated measures design was used that consisted of three sessions: theta tACS, gamma tACS and sham tACS. In total, four experiments were conducted which differed only with respect to placement of tACS electrodes (bilateral frontal, bilateral parietal, left fronto-parietal and right-fronto parietal. Healthy female students (N = 72 were randomly assigned to one of these groups, hence we were able to assess the efficacy of theta and gamma tACS applied over different brain areas, contrasted against sham stimulation. The pre-post/sham resting electroencephalogram (EEG analysis showed that theta tACS significantly affected theta amplitude, whereas gamma tACS had no significant effect on EEG amplitude in any of the frequency bands of interest. Gamma tACS did not significantly affect working memory performance compared to sham, and theta tACS led to inconsistent changes in performance on the n-back tasks. Active theta tACS significantly affected P3 amplitude and latency during performance on the n-back tasks in the bilateral parietal and right-fronto parietal protocols.

  17. Search for {theta}(1540){sup +} in the exclusive proton-induced reaction p+C(N){yields}{theta}{sup +} anti K{sup 0}+C(N) at the energy of 70 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Antipov, Yu.M.; Artamonov, A.V.; Batarin, V.A.; Eroshin, O.V. [Inst. for High Energy Physics, Protvino (Russian Federation); Kolgamov, V.Z. [Inst. of Theoretical and Experimental Physics, Moscow (RU)] [and others

    2004-09-01

    A search for narrow {theta}(1540){sup +}, a candidate for pentaquark baryon with positive strangeness, has been performed in an exclusive proton-induced reaction p+C(N){yields}{theta}{sup +} anti K{sup 0}+C(N) on carbon nuclei or quasifree nucleons at E{sub beam}=70 GeV ({radical}(s)=11.5 GeV) studying nK{sup +}, pK{sub S}{sup 0} and pK{sub L}{sup 0} decay channels of {theta}(1540){sup +} in four different final states of the {theta}{sup +} anti K{sup 0} system. In order to assess the quality of the identification of the final states with neutron or K {sup 0} {sub L}, we reconstructed {lambda}(1520){yields}nK{sup 0}{sub S} and {phi}{yields}K{sup 0}{sub L}K{sup 0}{sub S} decays in the calibration reactions p+C(N){yields}{lambda}(1520)K{sup +}+C(N) and p+C(N){yields}p{phi}+C(N). We found no evidence for narrow pentaquark peak in any of the studied final states and decay channels. Assuming that the production characteristics of the {theta}{sup +} anti K{sup 0} system are not drastically different from those of the {lambda}(1520)K{sup +} and p{phi} systems, we established upper limits on the cross-section ratios {sigma}({theta}{sup +} anti K{sup 0})/{sigma}({lambda}(1520)K{sup +})< 0.02 and {sigma}({theta}{sup +} anti K{sup 0})/{sigma}(p{phi})< 0.15 at 90% CL and a preliminary upper limit for the forward hemisphere cross-section {sigma}({theta}{sup +} anti K{sup 0})< 30 nb/nucleon. (orig.)

  18. Scylla IV-P theta pinch

    International Nuclear Information System (INIS)

    Bailey, A.G.; Chandler, G.I.; Ekdahl, C.A. Jr.; Lillberg, J.W.; Machalek, M.D.; Seibel, F.T.

    1976-01-01

    Scylla IV-P is a flexible, linear theta pinch designed to investigate high-density linear concepts, end-stoppering, alternate heating methods, and plasma injection techniques relevant to a pure fusion reactor and/or a fusion-fission hybrid system. The construction and experimental arrangement of the device are briefly described

  19. Double-Chooz: a search for {theta}{sub 13}

    Energy Technology Data Exchange (ETDEWEB)

    Mention, G. [APC/PCC, College de France, 75005 Paris (France)

    2005-08-15

    The Double-Chooz experiment goal is to search for a non-vanishing value of the {theta}{sub 13} neutrino mixing angle. This is the last step to accomplish prior moving towards a new era of precision measurements in the lepton sector. The current best constraint on the third mixing angle comes from the CHOOZ reactor neutrino experiment sin{sup 2}(2{theta}{sub 13}) < 0.2-0.14 (90% C.L., {delta}m{sub atm}{sup 2}=2.0-2.410{sup -3} eV{sup 2}). Double-Chooz will explore the range of sin{sup 2}(2{theta}{sub 13}) from 0.2 to 0.03-0.02, within three years of data taking. The improvement of the CHOOZ result requires an increase in the statistics, a reduction of the systematic error below one percent, and a careful control of the backgrounds. Therefore, Double-Chooz will use two identical detectors, one at 150 m and another at 1.05 km distance from the Chooz nuclear cores. In addition, we will use the near detector as a 'state of the art' prototype to investigate the potential of neutrinos for monitoring the civil nuclear power plants. The plan is to start operation with two detectors in 2008, and to reach a sin{sup 2}(2{theta}{sub 13}) sensitivity of 0.05 in 2009, and 0.03-0.02 in 2011.

  20. Steady state theta pinch concept for slow formation of FRC

    International Nuclear Information System (INIS)

    Hirano, K.

    1987-05-01

    A steady state high beta plasma flow through a channel along the magnetic field increasing downstream can be regarded as a ''steady state theta pinch'', because if we see the plasma riding on the flow we should observe very similar process taking place in a theta pinch. Anticipating to produce an FRC without using very high voltage technics such as the ones required in a conventional theta pinch, we have studied after the analogy a ''steady state reversed field theta pinch'' which is brought about by steady head-on collision of counter plasma streams along the channel as ejected from two identical co-axial plasma sources mounted at the both ends of the apparatus. The ideal Poisson and shock adiabatic flow models are employed for the analysis of the steady colliding process. It is demonstrated that an FRC involving large numbers of particles is produced only by the weak shock mode which is achieved in case energetic plasma flow is decelerated almost to be stagnated through Poisson adiabatic process before the streams are collided. (author)

  1. Transient reduction in theta power caused by interictal spikes in human temporal lobe epilepsy.

    Science.gov (United States)

    Manling Ge; Jundan Guo; Yangyang Xing; Zhiguo Feng; Weide Lu; Xinxin Ma; Yuehua Geng; Xin Zhang

    2017-07-01

    The inhibitory impacts of spikes on LFP theta rhythms(4-8Hz) are investigated around sporadic spikes(SSs) based on intracerebral EEG of 4 REM sleep patients with temporal lobe epilepsy(TLE) under the pre-surgical monitoring. Sequential interictal spikes in both genesis area and extended propagation pathway are collected, that, SSs genesis only in anterior hippocampus(aH)(possible propagation pathway in Entorhinal cortex(EC)), only in EC(possible propagation pathway in aH), and in both aH and EC synchronously. Instantaneous theta power was estimated by using Gabor wavelet transform, and theta power level was estimated by averaged over time and frequency before SSs(350ms pre-spike) and after SSs(350ms post-spike). The inhibitory effect around spikes was evaluated by the ratio of theta power level difference between pre-spike and post-spike to pre-spike theta power level. The findings were that theta power level was reduced across SSs, and the effects were more sever in the case of SSs in both aH and EC synchronously than either SSs only in EC or SSs only in aH. It is concluded that interictal spikes impair LFP theta rhythms transiently and directly. The work suggests that the reduction of theta power after the interictal spike might be an evaluation indicator of damage of epilepsy to human cognitive rhythms.

  2. Chasing {theta}{sub 13} with new reactor neutrino experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lasserre, Th. [DSM/DAPNIA/SPP, CEA/Saclay, 91191 Gif-sur-Yvette (France)

    2005-12-15

    It is now widely accepted that a new middle baseline disappearance reactor neutrino experiment with multiple detectors could provide a clean measurement of the {theta}{sub 13} mixing angle, free from any parameter degeneracies and correlations induced by matter effect and the unknown leptonic Dirac CP phase. The current best constraint on the third mixing angle comes from the Chooz reactor neutrino experiment sin{sup 2}(2{theta}{sub 13})<0.2 (90 % C.L., {delta}m{sub atm}{sup 2}=2.010{sup -3} eV{sup 2}). Several projects of experiment, with different timescales, have been proposed over the last two years all around the world. Their sensitivities range from sin{sup 2}(2{theta}{sub 13})<0.01 to 0.03, having thus an excellent discovery potential of the {nu}{sub e} fraction of {nu}{sub 3}.

  3. Characterizing the roles of alpha and theta oscillations in multisensory attention.

    Science.gov (United States)

    Keller, Arielle S; Payne, Lisa; Sekuler, Robert

    2017-05-01

    Cortical alpha oscillations (8-13Hz) appear to play a role in suppressing distractions when just one sensory modality is being attended, but do they also contribute when attention is distributed over multiple sensory modalities? For an answer, we examined cortical oscillations in human subjects who were dividing attention between auditory and visual sequences. In Experiment 1, subjects performed an oddball task with auditory, visual, or simultaneous audiovisual sequences in separate blocks, while the electroencephalogram was recorded using high-density scalp electrodes. Alpha oscillations were present continuously over posterior regions while subjects were attending to auditory sequences. This supports the idea that the brain suppresses processing of visual input in order to advantage auditory processing. During a divided-attention audiovisual condition, an oddball (a rare, unusual stimulus) occurred in either the auditory or the visual domain, requiring that attention be divided between the two modalities. Fronto-central theta band (4-7Hz) activity was strongest in this audiovisual condition, when subjects monitored auditory and visual sequences simultaneously. Theta oscillations have been associated with both attention and with short-term memory. Experiment 2 sought to distinguish these possible roles of fronto-central theta activity during multisensory divided attention. Using a modified version of the oddball task from Experiment 1, Experiment 2 showed that differences in theta power among conditions were independent of short-term memory load. Ruling out theta's association with short-term memory, we conclude that fronto-central theta activity is likely a marker of multisensory divided attention. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Chemotherapy disrupts learning, neurogenesis and theta activity in the adult brain.

    Science.gov (United States)

    Nokia, Miriam S; Anderson, Megan L; Shors, Tracey J

    2012-12-01

    Chemotherapy, especially if prolonged, disrupts attention, working memory and speed of processing in humans. Most cancer drugs that cross the blood-brain barrier also decrease adult neurogenesis. Because new neurons are generated in the hippocampus, this decrease may contribute to the deficits in working memory and related thought processes. The neurophysiological mechanisms that underlie these deficits are generally unknown. A possible mediator is hippocampal oscillatory activity within the theta range (3-12 Hz). Theta activity predicts and promotes efficient learning in healthy animals and humans. Here, we hypothesised that chemotherapy disrupts learning via decreases in hippocampal adult neurogenesis and theta activity. Temozolomide was administered to adult male Sprague-Dawley rats in a cyclic manner for several weeks. Treatment was followed by training with different types of eyeblink classical conditioning, a form of associative learning. Chemotherapy reduced both neurogenesis and endogenous theta activity, as well as disrupted learning and related theta-band responses to the conditioned stimulus. The detrimental effects of temozolomide only occurred after several weeks of treatment, and only on a task that requires the association of events across a temporal gap and not during training with temporally overlapping stimuli. Chemotherapy did not disrupt the memory for previously learned associations, a memory independent of (new neurons in) the hippocampus. In conclusion, prolonged systemic chemotherapy is associated with a decrease in hippocampal adult neurogenesis and theta activity that may explain the selective deficits in processes of learning that describe the 'chemobrain'. © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  5. Plasticity in behavioural responses and resistance to temperature stress in Musca domestica

    DEFF Research Database (Denmark)

    Kjaersgaard, Anders; Blackenhorn, Wolf U.; Pertoldi, Cino

    2015-01-01

    , at the stressful high temperature Spanish flies flew the furthest and Danish flies the shortest distance. Neither body size nor wing loading affected flight performance, although flies with narrower wings tended to fly further (wing shape effect). Swiss flies were most active in terms of locomotor activity......Organisms can respond to and cope with stressful environments in a number of ways including behavioural, morphological and physiological adjustments. To understand the role of behavioural traits in thermal adaptations we compared heat resistance, locomotor (walking and flying) activity, flight...... performance and morphology of three European populations of Musca domestica (Diptera: Muscidae) originating from different thermal conditions (Spain, Switzerland and Denmark) at benign and stressful high temperatures. Spanish flies showed greater heat resistance than Swiss and Danish flies. Similarly...

  6. Establishing the Thematic Structure and Investigating the most Prominent Theta Roles Used in Sindhi Language

    Directory of Open Access Journals (Sweden)

    Zahid Ali Veesar

    2015-07-01

    Full Text Available This study focuses on the thematic structure of the Sindhi verbs to find theta roles in the Sindhi language. The study tries to answer the research questions; “What are the thematic structures of Sindhi verbs?” and “What are the prominent theta roles in the Sindhi language?” It examines the argument/thematic structure of Sindhi verbs and also finds the theta roles assigned by the Sindhi verbs to their arguments along with the most prominent theta roles used in the Sindhi language. The data come from the two interviews taken from two young native Sindhi speakers, which consist of 2 hours conversation having 1,669 sentences in natural spoken version of the Sindhi language. Towards the end, it has been found that the Sindhi language has certain theta roles which are assigned by the verbs to their arguments in sentences. Each verb phrase in our data is thus examined and studied in detail in terms of Argument/Thematic structure in order to find theta roles in Sindhi language. Thus, in this regard, each verb phrase (in a sentence has been examined with the help of Carnie’s theoretical framework (Thematic Relation and Theta Roles: 2006 in order to find the prominent theta roles in the Sindhi language. The data have been examined and analysed on the basis of the Carnie’s theoretical framework. The study finds that the Sindhi language has all (09 theta roles which have been proposed by Carnie (2006. It has been found that six prominent theta roles out of nine are used prominently in Sindhi. The six prominent theta roles in Sindhi language are: agent, theme, beneficiary, recipient, locative and goal.

  7. Mixing angle theta and magnetic monopole in Weinberg's unified gauge theory

    International Nuclear Information System (INIS)

    Hsu, J.P.

    1975-01-01

    Gauge symmetry admits a local unit isovector and leads to the magnetic monopoles in Weinberg's unified theory. One predicts sin 2 theta = 1 / 2 for the mixing angle theta on the basis of Dirac's condition for charge quantization. This interesting result should be tested experimentally

  8. The Coupling between Gamma and Theta Oscillation and Visuotactile Integration Process

    Directory of Open Access Journals (Sweden)

    Noriaki Kanayama

    2011-10-01

    Full Text Available Some researches revealed the relationship between multisensory integration and EEG oscillations. Previous studies revealed that the visuotactile integration process could be explained by gamma and theta band oscillation. In addition, recent studies have showed the possibility that a coupling between oscillations at the different frequency bands plays an important role on the multisensory integration system. This study aimed to investigate whether the gamma and theta oscillations show the coupling during the visuotactile integration. Using congruency effect paradigm only for left hand, we measured scalp EEG during simultaneous presentation of “spatially congruent” or “spatially incongruent” visuotactile stimuli. In Experiment 1, the proportion of the spatially congruent trials (80% vs 20% was changed across the experimental blocks. The results showed that the relationship between gamma power and theta phase at the parietal area was modulated by the proportion. In Experiment 2, the saliency of the vibration stimulus (0dB vs −20dB was changed across trials. The results showed that the relationship between gamma power and theta phase was immune to the saliency. These results suggest that multisensory integration process has a plasticity, which is modulated by the proportion of congruent trial, and the process could be explained by the coupling between gamma/theta oscillations.

  9. Indefinite theta series and generalized error functions

    CERN Document Server

    Alexandrov, Sergei; Manschot, Jan; Pioline, Boris

    2016-01-01

    Theta series for lattices with indefinite signature $(n_+,n_-)$ arise in many areas of mathematics including representation theory and enumerative algebraic geometry. Their modular properties are well understood in the Lorentzian case ($n_+=1$), but have remained obscure when $n_+\\geq 2$. Using a higher-dimensional generalization of the usual (complementary) error function, discovered in an independent physics project, we construct the modular completion of a class of `conformal' holomorphic theta series ($n_+=2$). As an application, we determine the modular properties of a generalized Appell-Lerch sum attached to the lattice ${\\operatorname A}_2$, which arose in the study of rank 3 vector bundles on $\\mathbb{P}^2$. The extension of our method to $n_+>2$ is outlined.

  10. Patterns of coupled theta activity in amygdala-hippocampal-prefrontal cortical circuits during fear extinction.

    Directory of Open Access Journals (Sweden)

    Jörg Lesting

    Full Text Available Signals related to fear memory and extinction are processed within brain pathways involving the lateral amygdala (LA for formation of aversive stimulus associations, the CA1 area of the hippocampus for context-dependent modulation of these associations, and the infralimbic region of the medial prefrontal cortex (mPFC for extinction processes. While many studies have addressed the contribution of each of these modules individually, little is known about their interactions and how they function as an integrated system. Here we show, by combining multiple site local field potential (LFP and unit recordings in freely behaving mice in a fear conditioning paradigm, that theta oscillations may provide a means for temporally and functionally connecting these modules. Theta oscillations occurred with high specificity in the CA1-LA-mPFC network. Theta coupling increased between all areas during retrieval of conditioned fear, and declined during extinction learning. During extinction recall, theta coupling partly rebounded in LA-mPFC and CA1-mPFC, and remained at a low level in CA1-LA. Interfering with theta coupling through local electrical microstimulation in CA1-LA affected conditioned fear and extinction recall depending on theta phase. These results support the hypothesis that theta coupling provides a means for inter-areal coordination in conditioned behavioral responsiveness. More specifically, theta oscillations seem to contribute to a population code indicating conditioned stimuli during recall of fear memory before and after extinction.

  11. A Precision Measurement of sin$^{2}\\theta$$_{w}$ from Semileptonic Neutrino Scattering

    CERN Document Server

    Wotschack, Jorg

    1987-01-01

    There is considerable interest in measuring the electroweak mixing parameter sin$^{2}\\Theta$$_{w}$, of the Glashow-Salam-Weinberg theory $^{1}$ as precisely as possible: first, its value may be predicted by models of Grand Unification;$^{2}$ second, precise measurements of sin$^{2}\\Theta$$_{w}$ from different processes would test the validity of electroweak radiative corrections. $^{3,$}$. Different methods have been used to determine sin$^{2}\\Theta$$_{w}$, over a large range of $Q^{2}$ values. FIGURE 1 gives a compilation of sin$^{2}\\Theta$$_{w}$ with remarkable agreement between the results. At present, it is most precisely determined in semileptonic neutrino-nucleon scattering from the ratio of neutral current (NC) to charged current (CC) cross and in proton-antiproton collisions from the W boson mass. $^{10,11}$.

  12. Optogenetic activation of septal cholinergic neurons suppresses sharp wave ripples and enhances theta oscillations in the hippocampus.

    Science.gov (United States)

    Vandecasteele, Marie; Varga, Viktor; Berényi, Antal; Papp, Edit; Barthó, Péter; Venance, Laurent; Freund, Tamás F; Buzsáki, György

    2014-09-16

    Theta oscillations in the limbic system depend on the integrity of the medial septum. The different populations of medial septal neurons (cholinergic and GABAergic) are assumed to affect different aspects of theta oscillations. Using optogenetic stimulation of cholinergic neurons in ChAT-Cre mice, we investigated their effects on hippocampal local field potentials in both anesthetized and behaving mice. Cholinergic stimulation completely blocked sharp wave ripples and strongly suppressed the power of both slow oscillations (0.5-2 Hz in anesthetized, 0.5-4 Hz in behaving animals) and supratheta (6-10 Hz in anesthetized, 10-25 Hz in behaving animals) bands. The same stimulation robustly increased both the power and coherence of theta oscillations (2-6 Hz) in urethane-anesthetized mice. In behaving mice, cholinergic stimulation was less effective in the theta (4-10 Hz) band yet it also increased the ratio of theta/slow oscillation and theta coherence. The effects on gamma oscillations largely mirrored those of theta. These findings show that medial septal cholinergic activation can both enhance theta rhythm and suppress peri-theta frequency bands, allowing theta oscillations to dominate.

  13. Testing the effects of adolescent alcohol use on adult conflict-related theta dynamics.

    Science.gov (United States)

    Harper, Jeremy; Malone, Stephen M; Iacono, William G

    2017-11-01

    Adolescent alcohol use (AAU) is associated with brain anomalies, but less is known about long-term neurocognitive effects. Despite theoretical models linking AAU to diminished cognitive control, empirical work testing this relationship with specific cognitive control neural correlates (e.g., prefrontal theta-band EEG dynamics) remains scarce. A longitudinal twin design was used to test the hypothesis that greater AAU is associated with reduced conflict-related EEG theta-band dynamics in adulthood, and to examine the genetic/environmental etiology of this association. In a large (N=718) population-based prospective twin sample, AAU was assessed at ages 11/14/17. Twins completed a flanker task at age 29 to elicit EEG theta-band medial frontal cortex (MFC) power and medial-dorsal prefrontal cortex (MFC-dPFC) connectivity. Two complementary analytic methods (cotwin control analysis; biometric modeling) were used to disentangle the genetic/shared environmental risk towards AAU from possible alcohol exposure effects on theta dynamics. AAU was negatively associated with adult cognitive control-related theta-band MFC power and MFC-dPFC functional connectivity. Genetic influences primarily underlie these associations. Findings provide strong evidence that genetic factors underlie the comorbidity between AAU and diminished cognitive control-related theta dynamics in adulthood. Conflict-related theta-band dynamics appear to be candidate brain-based endophenotypes/mechanisms for AAU. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  14. Age-related changes of frontal-midline theta is predictive of efficient memory maintenance.

    Science.gov (United States)

    Kardos, Z; Tóth, B; Boha, R; File, B; Molnár, M

    2014-07-25

    Frontal areas are thought to be the coordinators of working memory processes by controlling other brain areas reflected by oscillatory activities like frontal-midline theta (4-7 Hz). With aging substantial changes can be observed in the frontal brain areas, presumably leading to age-associated changes in cortical correlates of cognitive functioning. The present study aimed to test whether altered frontal-midline theta dynamics during working memory maintenance may underlie the capacity deficits observed in older adults. 33-channel EEG was recorded in young (18-26 years, N=20) and old (60-71 years, N=16) adults during the retention period of a visual delayed match-to-sample task, in which they had to maintain arrays of 3 or 5 colored squares. An additional visual odd-ball task was used to be able to measure the electrophysiological indices of sustained attentional processes. Old participants showed reduced frontal theta activity during both tasks compared to the young group. In the young memory maintenance-related frontal-midline theta activity was shown to be sensitive both to the increased memory demands and to efficient subsequent memory performance, whereas the old adults showed no such task-related difference in the frontal theta activity. The decrease of frontal-midline theta activity in the old group indicates that cerebral aging may alter the cortical circuitries of theta dynamics, thereby leading to age-associated decline of working memory maintenance function. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  15. The fermion boundary condition and the THETA-angle in QED2

    International Nuclear Information System (INIS)

    Hrasko, P.

    1983-09-01

    The order parameter of the Schwinger model is calculated in the Euclidean functional integral approach. It is shown that the symmetry breaking angle THETA is intimately connected to the boundary condition imposed on the fermions. The transition to the Euclidean description involves both imaginary time and imaginary THETA. (author)

  16. Theta-rhythmic drive between medial septum and hippocampus in slow-wave sleep and microarousal: a Granger causality analysis.

    Science.gov (United States)

    Kang, D; Ding, M; Topchiy, I; Shifflett, L; Kocsis, B

    2015-11-01

    Medial septum (MS) plays a critical role in controlling the electrical activity of the hippocampus (HIPP). In particular, theta-rhythmic burst firing of MS neurons is thought to drive lasting HIPP theta oscillations in rats during waking motor activity and REM sleep. Less is known about MS-HIPP interactions in nontheta states such as non-REM sleep, in which HIPP theta oscillations are absent but theta-rhythmic burst firing in subsets of MS neurons is preserved. The present study used Granger causality (GC) to examine the interaction patterns between MS and HIPP in slow-wave sleep (SWS, a nontheta state) and during its short interruptions called microarousals (a transient theta state). We found that during SWS, while GC revealed a unidirectional MS→HIPP influence over a wide frequency band (2-12 Hz, maximum: ∼8 Hz), there was no theta peak in the hippocampal power spectra, indicating a lack of theta activity in HIPP. In contrast, during microarousals, theta peaks were seen in both MS and HIPP power spectra and were accompanied by bidirectional GC with MS→HIPP and HIPP→MS theta drives being of equal magnitude. Thus GC in a nontheta state (SWS) vs. a theta state (microarousal) primarily differed in the level of HIPP→MS. The present findings suggest a modification of our understanding of the role of MS as the theta generator in two regards. First, a MS→HIPP theta drive does not necessarily induce theta field oscillations in the hippocampus, as found in SWS. Second, HIPP theta oscillations entail bidirectional theta-rhythmic interactions between MS and HIPP. Copyright © 2015 the American Physiological Society.

  17. Frontal Theta Activity Supports Detecting Mismatched Information in Visual Working Memory.

    Science.gov (United States)

    Liang, Tengfei; Hu, Zhonghua; Liu, Qiang

    2017-01-01

    During the comparison stage of visual working memory (VWM) processing, detecting the mismatch between the external sensory input and internal representations is a crucial cognitive ability for human, but the neural mechanism behind it remains largely unclear. The present study investigated the role of frontal theta power in detecting the mismatched information in VWM in a delayed matching task. A control task required to compare two simultaneously presented visual figures was also designed as a contrast to exclude the possibility that frontal theta activity just reflecting the non-memory-related behavioral conflicts. To better characterize the control mechanisms shaped by the frontal theta oscillation in human VWM, colored shapes were adopted as materials while both the task-relevant shape feature and task-irrelevant color feature could be mismatched. We found that the response times of participants were significantly delayed under the relevant- and irrelevant-mismatch conditions in both tasks and the conjunction-mismatch condition in delayed matching task. While our EEG data showed that increased frontal theta power was only observed under the relevant- and conjunction-mismatch conditions in the delayed matching task, but not the control task. These findings suggest that the frontal distributed theta activity observed here reflects the detection of mismatched information during the comparison stage of VWM, rather than the response-related conflicts. Furthermore, it is consistent with the proposal that theta-band oscillation can act as a control mechanism in working memory function so that the target-mismatched information in VWM could be successfully tracked. We also propose a possible processing structure to explain the neural dynamics underlying the mismatch detection process in VWM.

  18. Frontal Theta Activity Supports Detecting Mismatched Information in Visual Working Memory

    Directory of Open Access Journals (Sweden)

    Tengfei Liang

    2017-10-01

    Full Text Available During the comparison stage of visual working memory (VWM processing, detecting the mismatch between the external sensory input and internal representations is a crucial cognitive ability for human, but the neural mechanism behind it remains largely unclear. The present study investigated the role of frontal theta power in detecting the mismatched information in VWM in a delayed matching task. A control task required to compare two simultaneously presented visual figures was also designed as a contrast to exclude the possibility that frontal theta activity just reflecting the non-memory-related behavioral conflicts. To better characterize the control mechanisms shaped by the frontal theta oscillation in human VWM, colored shapes were adopted as materials while both the task-relevant shape feature and task-irrelevant color feature could be mismatched. We found that the response times of participants were significantly delayed under the relevant- and irrelevant-mismatch conditions in both tasks and the conjunction-mismatch condition in delayed matching task. While our EEG data showed that increased frontal theta power was only observed under the relevant- and conjunction-mismatch conditions in the delayed matching task, but not the control task. These findings suggest that the frontal distributed theta activity observed here reflects the detection of mismatched information during the comparison stage of VWM, rather than the response-related conflicts. Furthermore, it is consistent with the proposal that theta-band oscillation can act as a control mechanism in working memory function so that the target-mismatched information in VWM could be successfully tracked. We also propose a possible processing structure to explain the neural dynamics underlying the mismatch detection process in VWM.

  19. Generalized Bilinear Differential Operators, Binary Bell Polynomials, and Exact Periodic Wave Solution of Boiti-Leon-Manna-Pempinelli Equation

    Directory of Open Access Journals (Sweden)

    Huanhe Dong

    2014-01-01

    Full Text Available We introduce how to obtain the bilinear form and the exact periodic wave solutions of a class of (2+1-dimensional nonlinear integrable differential equations directly and quickly with the help of the generalized Dp-operators, binary Bell polynomials, and a general Riemann theta function in terms of the Hirota method. As applications, we solve the periodic wave solution of BLMP equation and it can be reduced to soliton solution via asymptotic analysis when the value of p is 5.

  20. Musca domestica laboratory susceptibility to three ethnobotanical culinary plants.

    Science.gov (United States)

    El Zayyat, Elham A; Soliman, Mohammed I; Elleboudy, Noha A; Ofaa, Shaimaa E

    2015-10-01

    Throughout history, synanthropic Musca domestica had remained a worldwide problem whenever poor sanitation and bad hygienic conditions exists. Houseflies growing resistance to chemical insecticides are a rising environmental problem that necessitates search for alternatives. Mentha cervina, Ocimum basilicum, and Coriandrum sativum were tested for bioactivity on M. domestica adults and larvae. They are culinary Mediterranean plants. In adulticidal bioassay, using both CDC bottles and fumigation techniques, basil was the most effective extract with LC50 1.074 and 34.996 g/L, respectively. Concerning larvicidal bioassay by fumigation technique, coriander had the highest toxicity index with LC50 29.521 g/L. In both dipping and feeding technique, basil had the highest toxicity with LC50 32.643 and 0.749 g/L, respectively. Basil showed the highest toxicity results in four out of the five models tested followed by coriander then mint; this result highlights the potentiality of basil as a green insecticide in management of flies and opens new insight in the industrialization of basil-based fly control products.

  1. Are the iota(1440) and theta(1640) glueballs or quarkonia

    International Nuclear Information System (INIS)

    Ono, S.; Pene, O.

    1982-01-01

    We study the possibility that the iota (1440) and theta (1640) are radially excited quarkonium states (2S and 2P). Their masses, total decay rates and psi → iotaγ, thetaγ branching ratios are roughly in agreement with this hypothesis but deltaπ dominance in iota decay is difficult to explain. We propose clear tests to check if they are quarkonium states. (orig.)

  2. Theta Phase Synchronization Is the Glue that Binds Human Associative Memory.

    Science.gov (United States)

    Clouter, Andrew; Shapiro, Kimron L; Hanslmayr, Simon

    2017-10-23

    Episodic memories are information-rich, often multisensory events that rely on binding different elements [1]. The elements that will constitute a memory episode are processed in specialized but distinct brain modules. The binding of these elements is most likely mediated by fast-acting long-term potentiation (LTP), which relies on the precise timing of neural activity [2]. Theta oscillations in the hippocampus orchestrate such timing as demonstrated by animal studies in vitro [3, 4] and in vivo [5, 6], suggesting a causal role of theta activity for the formation of complex memory episodes, but direct evidence from humans is missing. Here, we show that human episodic memory formation depends on phase synchrony between different sensory cortices at the theta frequency. By modulating the luminance of visual stimuli and the amplitude of auditory stimuli, we directly manipulated the degree of phase synchrony between visual and auditory cortices. Memory for sound-movie associations was significantly better when the stimuli were presented in phase compared to out of phase. This effect was specific to theta (4 Hz) and did not occur in slower (1.7 Hz) or faster (10.5 Hz) frequencies. These findings provide the first direct evidence that episodic memory formation in humans relies on a theta-specific synchronization mechanism. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Fast entrainment of human electroencephalogram to a theta-band photic flicker during successful memory encoding

    Directory of Open Access Journals (Sweden)

    Naoyuki eSato

    2013-05-01

    Full Text Available Theta band power (4-8Hz in the scalp electroencephalogram (EEG is thought to be stronger during memory encoding for subsequently remembered items than for forgotten items. According to simultaneous EEG-functional magnetic resonance imaging (fMRI measurements, the memory-dependent EEG theta is associated with multiple regions of the brain. This suggests that the multiple regions cooperate with EEG theta synchronization during successful memory encoding. However, a question still remains: What kind of neural dynamic organizes such a memory-dependent global network? In this study, the modulation of the EEG theta entrainment property during successful encoding was hypothesized to lead to EEG theta synchronization among a distributed network. Then, a transient response of EEG theta to a theta-band photic flicker with a short duration was evaluated during memory encoding. In the results, flicker-induced EEG power increased and decreased with a time constant of several hundred milliseconds following the onset and the offset of the flicker, respectively. Importantly, the offset response of EEG power was found to be significantly decreased during successful encoding. Moreover, the offset response of the phase locking index was also found to associate with memory performance. According to computational simulations, the results are interpreted as a smaller time constant (i.e., faster response of a driven harmonic oscillator rather than a change in the spontaneous oscillatory input. This suggests that the fast response of EEG theta forms a global EEG theta network among memory-related regions during successful encoding, and it contributes to a flexible formation of the network along the time course.

  4. Fast entrainment of human electroencephalogram to a theta-band photic flicker during successful memory encoding.

    Science.gov (United States)

    Sato, Naoyuki

    2013-01-01

    Theta band power (4-8 Hz) in the scalp electroencephalogram (EEG) is thought to be stronger during memory encoding for subsequently remembered items than for forgotten items. According to simultaneous EEG-functional magnetic resonance imaging (fMRI) measurements, the memory-dependent EEG theta is associated with multiple regions of the brain. This suggests that the multiple regions cooperate with EEG theta synchronization during successful memory encoding. However, a question still remains: What kind of neural dynamic organizes such a memory-dependent global network? In this study, the modulation of the EEG theta entrainment property during successful encoding was hypothesized to lead to EEG theta synchronization among a distributed network. Then, a transient response of EEG theta to a theta-band photic flicker with a short duration was evaluated during memory encoding. In the results, flicker-induced EEG power increased and decreased with a time constant of several hundred milliseconds following the onset and the offset of the flicker, respectively. Importantly, the offset response of EEG power was found to be significantly decreased during successful encoding. Moreover, the offset response of the phase locking index was also found to associate with memory performance. According to computational simulations, the results are interpreted as a smaller time constant (i.e., faster response) of a driven harmonic oscillator rather than a change in the spontaneous oscillatory input. This suggests that the fast response of EEG theta forms a global EEG theta network among memory-related regions during successful encoding, and it contributes to a flexible formation of the network along the time course.

  5. Changes in hippocampal theta rhythm and their correlations with speed during different phases of voluntary wheel running in rats.

    Science.gov (United States)

    Li, J-Y; Kuo, T B J; Hsieh, I-T; Yang, C C H

    2012-06-28

    Hippocampal theta rhythm (4-12 Hz) can be observed during locomotor behavior, but findings on the relationship between locomotion speed and theta frequency are inconsistent if not contradictory. The inconsistency may be because of the difficulties that previous analyses and protocols have had excluding the effects of behavior training. We recorded the first or second voluntary wheel running each day, and assumed that theta frequency and activity are correlated with speed in different running phases. By simultaneously recording electroencephalography, physical activity, and wheel running speed, this experiment explored the theta oscillations during spontaneous running of the 12-h dark period. The recording was completely wireless and allowed the animal to run freely while being recorded in the wheel. Theta frequency and theta power of middle frequency were elevated before running and theta frequency, theta power of middle frequency, physical activity, and running speed maintained persistently high levels during running. The slopes of the theta frequency and theta activity (4-9.5 Hz) during the initial running were different compared to the same values during subsequent running. During the initial running, the running speed was positively correlated with theta frequency and with theta power of middle frequency. Over the 12-h dark period, the running speed did not positively correlate with theta frequency but was significantly correlated with theta power of middle frequency. Thus, theta frequency was associated with running speed only at the initiation of running. Furthermore, theta power of middle frequency was associated with speed and with physical activity during running when chronological order was not taken into consideration. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

  6. Variation of Musca domestica L. acetylcholinesterase in Danish housefly populations

    DEFF Research Database (Denmark)

    Kristensen, Michael; Huang, Jing; Qiao, Chuan-Ling

    2006-01-01

    Anti-cholinesterase resistance is in many cases caused by modified acetylcholinesterase (MACE). A comparison was made of toxicological data and AChE activity gathered from 21 field populations and nine laboratory strains of houseflies, Musca domestica L., to elucidate the best way of generating...... data to provide advice for management strategies and gathering information for resistance risk assessment on the organophosphates azamethiphos and dimethoate and the carbamate methomyl, which have been the primary insecticides used against adult houseflies in Denmark. Cluster analysis was performed...... and > 2000 houseflies were assigned to one of three phenotypes based on total acetylcholinesterase activity as well as inhibition by azamethiphos, methomyl or omethoate. A cluster, i.e. a phenotype, with high total AChE activity and high sensitivity to azamethiphos and less sensitivity to inhibition...

  7. Theta coordinated error-driven learning in the hippocampus.

    Directory of Open Access Journals (Sweden)

    Nicholas Ketz

    Full Text Available The learning mechanism in the hippocampus has almost universally been assumed to be Hebbian in nature, where individual neurons in an engram join together with synaptic weight increases to support facilitated recall of memories later. However, it is also widely known that Hebbian learning mechanisms impose significant capacity constraints, and are generally less computationally powerful than learning mechanisms that take advantage of error signals. We show that the differential phase relationships of hippocampal subfields within the overall theta rhythm enable a powerful form of error-driven learning, which results in significantly greater capacity, as shown in computer simulations. In one phase of the theta cycle, the bidirectional connectivity between CA1 and entorhinal cortex can be trained in an error-driven fashion to learn to effectively encode the cortical inputs in a compact and sparse form over CA1. In a subsequent portion of the theta cycle, the system attempts to recall an existing memory, via the pathway from entorhinal cortex to CA3 and CA1. Finally the full theta cycle completes when a strong target encoding representation of the current input is imposed onto the CA1 via direct projections from entorhinal cortex. The difference between this target encoding and the attempted recall of the same representation on CA1 constitutes an error signal that can drive the learning of CA3 to CA1 synapses. This CA3 to CA1 pathway is critical for enabling full reinstatement of recalled hippocampal memories out in cortex. Taken together, these new learning dynamics enable a much more robust, high-capacity model of hippocampal learning than was available previously under the classical Hebbian model.

  8. Dendritic brushes under theta and poor solvent conditions

    Science.gov (United States)

    Gergidis, Leonidas N.; Kalogirou, Andreas; Charalambopoulos, Antonios; Vlahos, Costas

    2013-07-01

    The effects of solvent quality on the internal stratification of polymer brushes formed by dendron polymers up to third generation were studied by means of molecular dynamics simulations with Langevin thermostat. The distributions of polymer units, of the free ends, the radii of gyration, and the back folding probabilities of the dendritic spacers were studied at the macroscopic states of theta and poor solvent. For high grafting densities we observed a small decrease in the height of the brush as the solvent quality decreases. The internal stratification in theta solvent was similar to the one we found in good solvent, with two and in some cases three kinds of populations containing short dendrons with weakly extended spacers, intermediate-height dendrons, and tall dendrons with highly stretched spacers. The differences increase as the grafting density decreases and single dendron populations were evident in theta and poor solvent. In poor solvent at low grafting densities, solvent micelles, polymeric pinned lamellae, spherical and single chain collapsed micelles were observed. The scaling dependence of the height of the dendritic brush at high density brushes for both solvents was found to be in agreement with existing analytical results.

  9. Abnormal-induced theta activity supports early directed-attention network deficits in progressive MCI.

    Science.gov (United States)

    Deiber, Marie-Pierre; Ibañez, Vicente; Missonnier, Pascal; Herrmann, François; Fazio-Costa, Lara; Gold, Gabriel; Giannakopoulos, Panteleimon

    2009-09-01

    The electroencephalography (EEG) theta frequency band reacts to memory and selective attention paradigms. Global theta oscillatory activity includes a posterior phase-locked component related to stimulus processing and a frontal-induced component modulated by directed attention. To investigate the presence of early deficits in the directed attention-related network in elderly individuals with mild cognitive impairment (MCI), time-frequency analysis at baseline was used to assess global and induced theta oscillatory activity (4-6Hz) during n-back working memory tasks in 29 individuals with MCI and 24 elderly controls (EC). At 1-year follow-up, 13 MCI patients were still stable and 16 had progressed. Baseline task performance was similar in stable and progressive MCI cases. Induced theta activity at baseline was significantly reduced in progressive MCI as compared to EC and stable MCI in all n-back tasks, which were similar in terms of directed attention requirements. While performance is maintained, the decrease of induced theta activity suggests early deficits in the directed-attention network in progressive MCI, whereas this network is functionally preserved in stable MCI.

  10. The electric dipole moment of the deuteron from the QCD {theta}-term

    Energy Technology Data Exchange (ETDEWEB)

    Bsaisou, J.; Liebig, S. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Hanhart, C.; Nogga, A.; Wirzba, A. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich (Germany); Forschungszentrum Juelich, JARA - Forces And Matter Experiments, Juelich (Germany); Meissner, U.G. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich (Germany); Forschungszentrum Juelich, JARA - Forces And Matter Experiments, Juelich (Germany); Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Universitaet Bonn, Bethe Center for Theoretical Physics, Bonn (Germany)

    2013-03-15

    The two-nucleon contributions to the electric dipole moment (EDM) of the deuteron, induced by the QCD {theta}-term, are calculated in the framework of effective field theory up-to-and-including next-to-next-to-leading order. In particular we find for the difference of the deuteron EDM and the sum of proton and neutron EDM induced by the QCD {theta}-term a value of (- 5.4 {+-}3.9) anti {theta} x 10{sup -} {sup 4} e fm. The by far dominant uncertainty comes from the CP- and isospin-violating {pi}NN coupling constant. (orig.)

  11. Brain Responses to a 6-Hz Binaural Beat: Effects on General Theta Rhythm and Frontal Midline Theta Activity.

    Science.gov (United States)

    Jirakittayakorn, Nantawachara; Wongsawat, Yodchanan

    2017-01-01

    A binaural beat is a beat phenomenon that is generated by the dichotic presentation of two almost equivalent pure tones but with slightly different frequencies. The brain responses to binaural beats remain controversial; therefore, the aim of this study was to investigate theta activity responses to a binaural beat by controlling factors affecting localization, including beat frequency, carrier tone frequency, exposure duration, and recording procedure. Exposure to a 6-Hz binaural beat on a 250 Hz carrier tone for 30 min was utilized in this study. Quantitative electroencephalography (QEEG) was utilized as the recording modality. Twenty-eight participants were divided into experimental and control groups. Emotional states were evaluated by Brunel Mood Scale (BRMUS) before and after exposing to the stimulus. The results showed that theta activity was induced in the entire cortex within 10 min of exposure to the stimulus in the experimental group. Compared to the control group, theta activity was also induced at the frontal and parietal-central regions, which included the Fz position, and left hemisphere dominance was presented for other exposure durations. The pattern recorded for 10 min of exposure appeared to be brain functions of a meditative state. Moreover, tension factor of BRUMS was decreased in experimental group compared to control group which resembled the meditation effect. Thus, a 6-Hz binaural beat on a 250 Hz carrier tone was suggested as a stimulus for inducing a meditative state.

  12. Brain Responses to a 6-Hz Binaural Beat: Effects on General Theta Rhythm and Frontal Midline Theta Activity

    Directory of Open Access Journals (Sweden)

    Nantawachara Jirakittayakorn

    2017-06-01

    Full Text Available A binaural beat is a beat phenomenon that is generated by the dichotic presentation of two almost equivalent pure tones but with slightly different frequencies. The brain responses to binaural beats remain controversial; therefore, the aim of this study was to investigate theta activity responses to a binaural beat by controlling factors affecting localization, including beat frequency, carrier tone frequency, exposure duration, and recording procedure. Exposure to a 6-Hz binaural beat on a 250 Hz carrier tone for 30 min was utilized in this study. Quantitative electroencephalography (QEEG was utilized as the recording modality. Twenty-eight participants were divided into experimental and control groups. Emotional states were evaluated by Brunel Mood Scale (BRMUS before and after exposing to the stimulus. The results showed that theta activity was induced in the entire cortex within 10 min of exposure to the stimulus in the experimental group. Compared to the control group, theta activity was also induced at the frontal and parietal-central regions, which included the Fz position, and left hemisphere dominance was presented for other exposure durations. The pattern recorded for 10 min of exposure appeared to be brain functions of a meditative state. Moreover, tension factor of BRUMS was decreased in experimental group compared to control group which resembled the meditation effect. Thus, a 6-Hz binaural beat on a 250 Hz carrier tone was suggested as a stimulus for inducing a meditative state.

  13. Ophthalmomyiasis externa by Musca domestica in a case of orbital metastasis

    Directory of Open Access Journals (Sweden)

    Rose Mary Tomy

    2013-01-01

    Full Text Available Infestation of the living tissues of the eye, ocular adnexae or orbit by larvae of flies of the order Diptera is known as ophthalmomyiasis. Ophthalmomyiasis externa is a limited superficial infestation of external ocular structures such as conjunctiva and adnexae. A case of follicular carcinoma thyroid with orbital metastasis presenting as ophthalmomyiasis externa is reported. The patient presented with foul smelling ulcers of the medial and lateral orbital walls of the right eye extending into the lids and nose, teeming with maggots. Computerized Tomography (CT showed widespread bone destruction with extension into surrounding sinuses. Over 200 maggots were manually removed after immobilisation with turpentine oil instillation. Entomological examination showed it to be a case of accidental myiasis caused by the common housefly Musca domestica. The patient was managed conservatively and the ulcer cavities filled up with healthy granulation tissue. This case is presented on account of its rarity.

  14. The relationship between hippocampal EEG theta activity and locomotor behaviour in freely moving rats: effects of vigabatrin.

    Science.gov (United States)

    Bouwman, B M; van Lier, H; Nitert, H E J; Drinkenburg, W H I M; Coenen, A M L; van Rijn, C M

    2005-01-30

    The relationship between hippocampal electroencephalogram (EEG) theta activity and locomotor speed in both spontaneous and forced walking conditions was studied in rats after vigabatrin injection (500 mg/kg i.p.). Vigabatrin increased the percentage of time that rats spent being immobile. During spontaneous walking in the open field, the speed of locomotion was increased by vigabatrin, while theta peak frequency was decreased. Vigabatrin also reduced the theta peak frequency during forced (speed controlled) walking. There was only a weak positive correlation (r=0.22) between theta peak frequency and locomotor speed for the saline condition. Furthermore, vigabatrin abolishes the weak relationship between speed of locomotion and theta peak frequency. Vigabatrin and saline did not differ in the slope of the regression line, but showed different offset points at the theta peak frequency axis. Thus, other factors than speed of locomotion seem to be involved in determination of the theta peak frequency.

  15. Bi-Directional Theta Modulation between the Septo-Hippocampal System and the Mammillary Area in Free-Moving Rats

    Directory of Open Access Journals (Sweden)

    Ming Ruan

    2017-09-01

    Full Text Available Hippocampal (HPC theta oscillations have long been linked to various functions of the brain. Many cortical and subcortical areas that also exhibit theta oscillations have been linked to functional circuits with the hippocampus on the basis of coupled activities at theta frequencies. We examine, in freely moving rats, the characteristics of diencephalic theta local field potentials (LFPs recorded in the supramammillary/mammillary (SuM/MM areas that are bi-directionally connected to the HPC through the septal complex. Using partial directed coherence (PDC, we find support for previous suggestions that SuM modulates HPC theta at higher frequencies. We find weak separation of SuM and MM by dominant theta frequency recorded locally. Contrary to oscillatory cell activities under anesthesia where SuM is insensitive, but MM is sensitive to medial septal (MS inactivation, theta LFPs persisted and became indistinguishable after MS-inactivation. However, MS-inactivation attenuated SuM/MM theta power, while increasing the frequency of SuM/MM theta. MS-inactivation also reduced root mean squared power in both HPC and SuM/MM equally, but reduced theta power differentially in the time domain. We provide converging evidence that SuM is preferentially involved in coding HPC theta at higher frequencies, and that the MS-HPC circuit normally imposes a frequency-limiting modulation over the SuM/MM area as suggested by cell-based recordings in anesthetized animals. In addition, we provide evidence that the postulated SuM-MS-HPC-MM circuit is under complex bi-directional control, rather than SuM and MM having roles as unidirectional relays in the network.

  16. Search for $\\Theta^{++}$ Pentaquarks in the Exclusive Reaction $\\gamma p\\to K^+K^-p$

    Energy Technology Data Exchange (ETDEWEB)

    V. Kubarovsky; Marco Battaglieri; Raffaella De Vita; John Goett; Lei Guo; Gordon Mutchler; Paul Stoler; Dennis Weygand; Pawel Ambrozewicz; Marco Anghinolfi; Gegham Asryan; Harutyun AVAKIAN; Harutyun Avakian; H. Bagdasaryan; Nathan Baillie; Jacques Ball; Nathan Baltzell; V. Batourine; Ivan Bedlinski; Ivan Bedlinskiy; Matthew Bellis; Nawal Benmouna; Barry Berman; Angela Biselli; Sylvain Bouchigny; Sergey Boyarinov; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; Sharon Careccia; Daniel Carman; Shifeng Chen; Eric Clinton; Philip Cole; Patrick Collins; Philip Coltharp; Donald Crabb; Hall Crannell; Volker Crede; John Cummings; Rita De Masi; Daniel Dale; Enzo De Sanctis; Pavel Degtiarenko; Alexandre Deur; Kahanawita Dharmawardane; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; Latifa Elouadrhiri; Paul Eugenio; Gleb Fedotov; Herbert Funsten; Marianna Gabrielyan; Liping Gan; Michel Garcon; Ashot Gasparian; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; Oleksandr Glamazdin; John Goetz; Evgueni Golovatch; Atilla Gonenc; Christopher Gordon; Ralf Gothe; Keith Griffioen; Michel Guidal; Nevzat Guler; Vardan Gyurjyan; Cynthia Hadjidakis; Kawtar Hafidi; Rafael Hakobyan; John Hardie; F. Hersman; Kenneth Hicks; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; David Jenkins; Hyon-Suk Jo; Kyungseon Joo; Henry Juengst; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Franz Klein; Friedrich Klein; Alexei Klimenko; Mikhail Kossov; Laird Kramer; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Jeff Lachniet; Jean Laget; Jorn Langheinrich; David Lawrence; Tsung-shung Lee; Ji Li; Kenneth Livingston; Hai-jiang Lu; Marion MacCormick; Nikolai Markov; Bryan McKinnon; Bernhard Mecking; Joseph Melone; Mac Mestayer; Curtis Meyer; Tsutomu Mibe; Konstantin Mikhaylov; Ralph Minehart; Marco Mirazita; Rory Miskimen; Vasiliy Mochalov; Viktor Mokeev; Ludyvine Morand; Steven Morrow; Maryam Moteabbed; Pawel Nadel-Turonski; Itaru Nakagawa; Rakhsha Nasseripour; Silvia Niccolai; Gabriel Niculescu; Maria-Ioana Niculescu; Bogdan Niczyporuk; Megh Niroula; Rustam Niyazov; Mina Nozar; Mikhail Osipenko; Alexander Ostrovidov; Kijun Park; Evgueni Pasyuk; Craig Paterson; Joshua Pierce; Nikolay Pivnyuk; Dinko Pocanic; Oleg Pogorelko; Sergey Pozdnyakov; John Price; Yelena Prok; Dan Protopopescu; Brian Raue; Gregory Riccardi; Giovanni Ricco; Marco Ripani; Barry Ritchie; Federico Ronchetti; Guenther Rosner; Patrizia Rossi; Franck Sabatie; Carlos Salgado; Joseph Santoro; Vladimir Sapunenko; Reinhard Schumacher; Vladimir Serov; Youri Sharabian; Nikolay Shvedunov; Elton Smith; Lee Smith; Daniel Sober; Aleksey Stavinskiy; Samuel Stepanyan; Stepan Stepanyan; Burnham Stokes; Igor Strakovski; Steffen Strauch; Mauro Taiuti; David Tedeschi; Aram Teymurazyan; Ulrike Thoma; Avtandil Tkabladze; Svyatoslav Tkachenko; Luminita Todor; Clarisse Tur; Maurizio Ungaro; Michael Vineyard; Alexander Vlassov; Lawrence Weinstein; Michael Williams; Elliott Wolin; Michael Wood; Amrit Yegneswaran; Lorenzo Zana; Jixie Zhang; Bo Zhao

    2006-04-28

    The reaction {gamma}p {yields} K{sup +}K{sup -}p was studied at Jefferson Lab with photon energies from 1.8 to 3.8 GeV using a tagged photon beam. The goal was to search for a {Theta}{sup ++} pentaquark, a narrow doubly charged baryon state having strangeness S = +1 and isospin I = 1, in the pK{sup +} invariant mass spectrum. No statistically significant evidence of a {Theta}{sup ++} was found. Upper limits on the total and differential production cross section for the reaction {gamma}p {yields} K{sup -}{Theta}{sup ++} were obtained in the mass range from 1.5 to 2.0 GeV/c{sup 2}, with an upper limit of about 0.15 nb, 95% C.L. for a narrow resonance with a mass M{sub {Theta}{sup ++}} = 1.54 GeV/c{sup 2}. This result places a very stringent upper limit on the {Theta}{sup ++} width.

  17. Task-related modulation of anterior theta and posterior alpha EEG reflects top-down preparation

    Directory of Open Access Journals (Sweden)

    Park Hae-Jeong

    2010-06-01

    Full Text Available Abstract Background Prestimulus EEG alpha activity in humans has been considered to reflect ongoing top-down preparation for the performance of subsequent tasks. Since theta oscillations may be related to poststimulus top-down processing, we investigated whether prestimulus EEG theta activity also reflects top-down cognitive preparation for a stimulus. Results We recorded EEG data from 15 healthy controls performing a color and shape discrimination task, and used the wavelet transformation to investigate the time course and power of oscillatory activity in the signals. We observed a relationship between both anterior theta and posterior alpha power in the prestimulus period and the type of subsequent task. Conclusions Since task-differences were reflected in both theta and alpha activities prior to stimulus onset, both prestimulus theta (particularly around the anterior region and prestimulus alpha (particularly around the posterior region activities may reflect prestimulus top-down preparation for the performance of subsequent tasks.

  18. Delta-gamma-theta Hedging of Crude Oil Asian Options

    Directory of Open Access Journals (Sweden)

    Juraj Hruška

    2015-01-01

    Full Text Available Since Black-Scholes formula was derived, many methods have been suggested for vanilla as well as exotic options pricing. More of investing and hedging strategies have been developed based on these pricing models. Goal of this paper is to derive delta-gamma-theta hedging strategy for Asian options and compere its efficiency with gamma-delta-theta hedging combined with predictive model. Fixed strike Asian options are type of exotic options, whose special feature is that payoff is calculated from the difference of average market price and strike price for call options and vice versa for the put options. Methods of stochastic analysis are used to determine deltas, gammas and thetas of Asian options. Asian options are cheaper than vanilla options and therefore they are more suitable for precise portfolio creation. On the other hand their deltas are also smaller as well as profits. That means that they are also less risky and more suitable for hedging. Results, conducted on chosen commodity, confirm better feasibility of Asian options compering with vanilla options in sense of gamma hedging.

  19. Palmitic acid mediates hypothalamic insulin resistance by altering PKC-theta subcellular localization in rodents.

    Science.gov (United States)

    Benoit, Stephen C; Kemp, Christopher J; Elias, Carol F; Abplanalp, William; Herman, James P; Migrenne, Stephanie; Lefevre, Anne-Laure; Cruciani-Guglielmacci, Céline; Magnan, Christophe; Yu, Fang; Niswender, Kevin; Irani, Boman G; Holland, William L; Clegg, Deborah J

    2009-09-01

    Insulin signaling can be modulated by several isoforms of PKC in peripheral tissues. Here, we assessed whether one specific isoform, PKC-theta, was expressed in critical CNS regions that regulate energy balance and whether it mediated the deleterious effects of diets high in fat, specifically palmitic acid, on hypothalamic insulin activity in rats and mice. Using a combination of in situ hybridization and immunohistochemistry, we found that PKC-theta was expressed in discrete neuronal populations of the arcuate nucleus, specifically the neuropeptide Y/agouti-related protein neurons and the dorsal medial nucleus in the hypothalamus. CNS exposure to palmitic acid via direct infusion or by oral gavage increased the localization of PKC-theta to cell membranes in the hypothalamus, which was associated with impaired hypothalamic insulin and leptin signaling. This finding was specific for palmitic acid, as the monounsaturated fatty acid, oleic acid, neither increased membrane localization of PKC-theta nor induced insulin resistance. Finally, arcuate-specific knockdown of PKC-theta attenuated diet-induced obesity and improved insulin signaling. These results suggest that many of the deleterious effects of high-fat diets, specifically those enriched with palmitic acid, are CNS mediated via PKC-theta activation, resulting in reduced insulin activity.

  20. Experimental study of CF4 conical theta pinch plasma expanding into vacuum

    International Nuclear Information System (INIS)

    Pedrow, P.D.; Nasiruddin, A.M.

    1989-01-01

    Langmuir probe, photodiode, and optical multichannel analyzer (OMA) measurements have been made on a pulsed CF 4 conical theta pinch plasma. A cloud of CF 4 gas was puffed into a conical theta pinch coil, converted to plasma, and propelled into the vacuum region ahead of the expanding gas cloud. At a position 67 cm away from the conical theta pinch coil, the plasma arrived in separate packets that were about 20 μs in duration. The average drift velocity of these packets corresponded to an energy of about 3 eV. The OMA measurements showed that the second packet contained neutral atomic fluorine as well as charged particles

  1. The role of REM theta activity in emotional memory

    Directory of Open Access Journals (Sweden)

    Isabel Camilla Hutchison

    2015-10-01

    Full Text Available While NREM sleep has been strongly implicated in the reactivation and consolidation of memory traces, the role of REM sleep remains unclear. A growing body of research on humans and animals provide behavioral evidence for a role of REM sleep in the strengthening and modulation of emotional memories. Theta activity – which describes low frequency oscillations in the local field potential within the hippocampus, amygdala and neocortex – is a prominent feature of both wake and REM sleep in humans and rodents. Theta coherence between the hippocampus and amygdala drives large-scale PGO waves, the density of which predicts increases in plasticity-related gene expression. This could potentially facilitate the processing of emotional memory traces within the hippocampus during REM sleep. Further, the timing of hippocampal activity in relation to theta phase is vital in determining subsequent potentiation of neuronal activity. This could allow the emotionally modulated strengthening of novel and the gradual weakening of consolidated hippocampal memory traces observed in both wake and REM sleep. Hippocampal theta activity is also correlated with REM sleep acetylcholine levels – which are thought to reduce hippocampal afferent inputs in the neocortex. The additional low levels of noradrenaline during REM sleep, which facilitate recurrent activation within the neocortex, could allow the integration of novel memory traces previously consolidated during NREM sleep. We therefore propose that REM sleep mediates the prioritized processing of emotional memories within the hippocampus, the integration of previously consolidated memory traces within the neocortex, as well as the disengagement of consolidated neocortical memory traces from the hippocampus.

  2. Power of theta waves in the EEG of human subjects increases during recall of haptic information.

    Science.gov (United States)

    Grunwald, M; Weiss, T; Krause, W; Beyer, L; Rost, R; Gutberlet, I; Gertz, H J

    1999-02-05

    Several studies have reported a functional relationship between spectral power within the theta-band of the EEG (theta-power) and memory load while processing visual or semantic information. We investigated theta power during the processing of different complex haptic stimuli using a delayed recall design. The haptic explorations consisted of palpating the structure of twelve sunken reliefs with closed eyes. Subjects had to reproduce each relief by drawing it 10 s after the end of the exploration. The relationship between mean theta power and mean exploration time was analysed using a regression model. A linear relationship was found between the exploration time and theta power over fronto-central regions (Fp1, Fp2, F3, F7, F8, Fz, C3) directly before the recall of the relief. This result is interpreted in favour of the hypothesis that fronto-central theta power of the EEG correlates with the load of working memory independent of stimulus modality.

  3. Activation of GABAergic pathway by hypocretin in the median raphe nucleus (MRN) mediates stress-induced theta rhythm in rats.

    Science.gov (United States)

    Hsiao, Yi-Tse; Jou, Shuo-Bin; Yi, Pei-Lu; Chang, Fang-Chia

    2012-07-15

    The frequency of electroencephalograms (EEGs) is predominant in theta rhythm during stress (e.g., footshock) in rats. Median raphe nucleus (MRN) desynchronizes hippocampal theta waves via activation of GABAergic neurons in the medial septum-diagonal band of Broca (MS-DBB), a theta rhythm pacemaker. Increased hypocretin mediates stress responses in addition to the maintenance of wakefulness. Hypocretin receptors are abundant in the MRN, suggesting a possible role of hypocretin in modulating stress-induced theta rhythm. Our results indicated that the intensity of theta waves was enhanced by footshock and that a hypocretin receptor antagonist (TCS1102) suppressed the footshock-induced theta waves. Administration of hypocretin-1 (1 and 10 μg) and hypocretin-2 (10 μg) directly into the MRN simulated the effect of footshock and significantly increased theta waves. Co-administration of GABA(A) receptor antagonist, bicuculline, into the MRN blocked the increase of theta waves induced by hypocretins or footshock. These results suggested that stress enhances the release of hypocretins, activates GABAergic neurons in the MRN, blocks the ability of MRN to desynchronize theta waves, and subsequently increases the intensity of theta rhythm. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Ramanujan's mock theta functions.

    Science.gov (United States)

    Griffin, Michael; Ono, Ken; Rolen, Larry

    2013-04-09

    In his famous deathbed letter, Ramanujan introduced the notion of a mock theta function, and he offered some alleged examples. Recent work by Zwegers [Zwegers S (2001) Contemp Math 291:268-277 and Zwegers S (2002) PhD thesis (Univ of Utrecht, Utrecht, The Netherlands)] has elucidated the theory encompassing these examples. They are holomorphic parts of special harmonic weak Maass forms. Despite this understanding, little attention has been given to Ramanujan's original definition. Here, we prove that Ramanujan's examples do indeed satisfy his original definition.

  5. Evolution of resistance to pyrethroid insecticides in Musca domestica.

    Science.gov (United States)

    Scott, Jeffrey G

    2017-04-01

    Houseflies, Musca domestica L., are a significant pest because of the numerous diseases they transmit. Control of housefly populations, particularly at animal production facilities, is frequently done using pyrethroid insecticides which kill insects by prolonging the open time of the voltage-sensitive sodium channel (VSSC). Houseflies have evolved resistance to pyrethroids owing to mutations in Vssc and by cytochrome-P450-mediated detoxification. Three Vssc mutations are known: kdr (L1014F), kdr-his (L1014H) and super-kdr (M918T + L1014F). Generally, the levels of resistance conferred by these mutations are kdr-his resistance than kdr. P450-mediated resistance can result from overexpression of CYP6D1 or another P450 (unidentified) whose overexpression is linked to autosomes II or V. The initial use of field-stable pyrethroids resulted in different patterns of evolution across the globe, but with time these mutations have become more widespread in their distribution. What is known about the fitness costs of the resistance alleles in the absence of insecticide is discussed, particularly with respect to the current and future utility of pyrethroid insecticides. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  6. Why don't you like me? Midfrontal theta power in response to unexpected peer rejection feedback.

    Science.gov (United States)

    van der Molen, M J W; Dekkers, L M S; Westenberg, P M; van der Veen, F M; van der Molen, M W

    2017-02-01

    Social connectedness theory posits that the brain processes social rejection as a threat to survival. Recent electrophysiological evidence suggests that midfrontal theta (4-8Hz) oscillations in the EEG provide a window on the processing of social rejection. Here we examined midfrontal theta dynamics (power and inter-trial phase synchrony) during the processing of social evaluative feedback. We employed the Social Judgment paradigm in which 56 undergraduate women (mean age=19.67 years) were asked to communicate their expectancies about being liked vs. disliked by unknown peers. Expectancies were followed by feedback indicating social acceptance vs. rejection. Results revealed a significant increase in EEG theta power to unexpected social rejection feedback. This EEG theta response could be source-localized to brain regions typically reported during activation of the saliency network (i.e., dorsal anterior cingulate cortex, insula, inferior frontal gyrus, frontal pole, and the supplementary motor area). Theta phase dynamics mimicked the behavior of the time-domain averaged feedback-related negativity (FRN) by showing stronger phase synchrony for feedback that was unexpected vs. expected. Theta phase, however, differed from the FRN by also displaying stronger phase synchrony in response to rejection vs. acceptance feedback. Together, this study highlights distinct roles for midfrontal theta power and phase synchrony in response to social evaluative feedback. Our findings contribute to the literature by showing that midfrontal theta oscillatory power is sensitive to social rejection but only when peer rejection is unexpected, and this theta response is governed by a widely distributed neural network implicated in saliency detection and conflict monitoring. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Transmitter release in the neuromuscular synapse of the protein kinase C theta-deficient adult mouse.

    Science.gov (United States)

    Besalduch, Núria; Santafé, Manel M; Garcia, Neus; Gonzalez, Carmen; Tomás, Marta; Tomás, Josep; Lanuza, Maria A

    2011-04-01

    We studied structural and functional features of the neuromuscular junction in adult mice (P30) genetically deficient in the protein kinase C (PKC) theta isoform. Confocal and electron microscopy shows that there are no differences in the general morphology of the endplates between PKC theta-deficient and wild-type (WT) mice. Specifically, there is no difference in the density of the synaptic vesicles. However, the myelin sheath is not as thick in the intramuscular nerve fibers of the PKC theta-deficient mice. We found a significant reduction in the size of evoked endplate potentials and in the frequency of spontaneous, asynchronous, miniature endplate potentials in the PKC theta-deficient neuromuscular preparations in comparison with the WT, but the mean amplitude of the spontaneous potentials is not different. These changes indicate that PKC theta has a presynaptic role in the function of adult neuromuscular synapses. Copyright © 2010 Wiley-Liss, Inc.

  8. Enhanced Constraints on theta13 from A Three-Flavor Oscillation Analysis of Reactor Antineutrinos at KamLAND

    Energy Technology Data Exchange (ETDEWEB)

    The KamLAND Collaboration; Gando, A.; Gando, Y.; Ichimura, K.; Ikeda, H.; Inoue, K.; Kibe, Y.; Kishimoto, Y.; Koga, M.; Minekawa, Y.; Mitsui, T.; Morikawa, T.; Nagai, N.; Nakajima, K.; Nakamura, K.; Narita, K.; Shimizu, I.; Shimizu, Y.; Shirai, J.; Suekane, F.; Suzuki, A.; Takahashi, H.; Takahashi, N.; Takemoto, Y.; Tamae, K.; Watanabe, H.; Xu, B. D.; Yabumoto, H.; Yoshida, H.; Yoshida, S.; Enomoto, S.; Kozlov, A.; Murayama, H.; Grant, C.; Keefer, G.; Piepke, A.; Banks, T. I.; Bloxham, T.; Detwiler, J. A.; Freedman, S. J.; Fujikawa, B. K.; Han, K.; Kadel, R.; O' Donnell, T.; Steiner, H. M.; Dwyer, D. A.; McKeown, R. D.; Zhang, C.; Berger, B. E.; Lane, C. E.; Maricic, J.; Miletic, T.; Batygov, M.; Learned, J. G.; Matsuno, S.; Sakai, M.; Horton-Smith, G. A.; Downum, K. E.; Gratta, G.; Efremenko, Y.; Perevozchikov, O.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Heeger, K. M.; Decowski, M. P.

    2010-09-24

    We present new constraints on the neutrino oscillation parameters {Delta}m{sub 21}{sup 2}, {theta}{sub 12}, and {theta}{sub 13} from a three-flavor analysis of solar and KamLAND data. The KamLAND data set includes data acquired following a radiopurity upgrade and amounts to a total exposure of 3.49 x 10{sup 32} target-proton-year. Under the assumption of CPT invariance, a two-flavor analysis ({theta}{sub 13} = 0) of the KamLAND and solar data yields the best-fit values tan{sup 2} {theta}{sub 12} = 0.444{sub -0.030}{sup +0.036} and {Delta}m{sub 21}{sup 2} = 7.50{sub -0.20}{sup +0.19} x 10{sup -5} eV{sup 2}; a three-flavor analysis with {theta}{sub 13} as a free parameter yields the best-fit values tan{sup 2} {theta}{sub 12} = 0.452{sub -0.033}{sup +0.035}, {Delta}m{sub 21}{sup 2} = 7.50{sub -0.20}{sup +0.19} x 10{sup -5}eV{sup 2}, and sin{sup 2} {theta}{sub 13} = 0.020{sub -0.016}{sup +0.016}. This {theta}{sub 13} interval is consistent with other recent work combining the CHOOZ, atmospheric and long-baseline accelerator experiments. We also present a new global {theta}{sub 13} analysis, incorporating the CHOOZ, atmospheric and accelerator data, which indicates sin{sup 2} {theta}{sub 13} = 0.017{sub -0.009}{sup +0.010}, a nonzero value at the 93% C.L. This finding will be further tested by upcoming accelerator and reactor experiments.

  9. Theta-alpha EEG phase distributions in the frontal area for dissociation of visual and auditory working memory.

    Science.gov (United States)

    Akiyama, Masakazu; Tero, Atsushi; Kawasaki, Masahiro; Nishiura, Yasumasa; Yamaguchi, Yoko

    2017-03-07

    Working memory (WM) is known to be associated with synchronization of the theta and alpha bands observed in electroencephalograms (EEGs). Although frontal-posterior global theta synchronization appears in modality-specific WM, local theta synchronization in frontal regions has been found in modality-independent WM. How frontal theta oscillations separately synchronize with task-relevant sensory brain areas remains an open question. Here, we focused on theta-alpha phase relationships in frontal areas using EEG, and then verified their functional roles with mathematical models. EEG data showed that the relationship between theta (6 Hz) and alpha (12 Hz) phases in the frontal areas was about 1:2 during both auditory and visual WM, and that the phase distributions between auditory and visual WM were different. Next, we used the differences in phase distributions to construct FitzHugh-Nagumo type mathematical models. The results replicated the modality-specific branching by orthogonally of the trigonometric functions for theta and alpha oscillations. Furthermore, mathematical and experimental results were consistent with regards to the phase relationships and amplitudes observed in frontal and sensory areas. These results indicate the important role that different phase distributions of theta and alpha oscillations have in modality-specific dissociation in the brain.

  10. Theta oscillations orchestrate medial temporal lobe and neocortex in remembering autobiographical memories.

    Science.gov (United States)

    Fuentemilla, L; Barnes, G R; Düzel, E; Levine, B

    2014-01-15

    Remembering autobiographical events can be associated with detailed visual imagery. The medial temporal lobe (MTL), precuneus and prefrontal cortex are held to jointly enable such vivid retrieval, but how these regions are orchestrated remains unclear. An influential prediction from animal physiology is that neural oscillations in theta frequency may be important. In this experiment, participants prospectively collected audio recordings describing personal autobiographical episodes or semantic knowledge over 2 to 7 months. These were replayed as memory retrieval cues while recording brain activity with magnetoencephalography (MEG). We identified a peak of theta power within a left MTL region of interest during both autobiographical and General Semantic retrieval. This MTL region was selectively phase-synchronized with theta oscillations in precuneus and medial prefrontal cortex, and this synchrony was higher during autobiographical as compared to General Semantic knowledge retrieval. Higher synchrony also predicted more detailed visual imagery during retrieval. Thus, theta phase-synchrony orchestrates in humans the MTL with a distributed neocortical memory network when vividly remembering autobiographical experiences. © 2013.

  11. Self-regulation of frontal-midline theta facilitates memory updating and mental set shifting

    Directory of Open Access Journals (Sweden)

    Stefanie eEnriquez-Geppert

    2014-12-01

    Full Text Available Frontal-midline (fm theta oscillations as measured via the electroencephalogram (EEG have been suggested as neural working language of executive functioning. Their power has been shown to increase when cognitive processing or task performance is enhanced. Thus, the question arises whether learning to increase fm-theta amplitudes would functionally impact the behavioral performance in tasks probing executive functions (EFs. Here, the effects of neurofeedback, a learning method to self-up-regulate fm-theta over frontal-midline electrodes, on the four most representative EFs, memory updating, set shifting, conflict monitoring, and motor inhibition are presented. Before beginning and after completing an individualized, eight-session gap-spaced neurofeedback intervention, the three-back, letter/number task-switching, Stroop, and stop-signal tasks were tested while measuring the EEG. Self-determined up-regulation of fm-theta and its putative role for executive functioning were compared to an active control group, the so-called pseudo-neurofeedback group. Task-related fm-theta activity after training differed significantly between groups. More importantly, though, after neurofeedback significantly enhanced behavioral performance was observed. The training group showed higher accuracy scores in the three-back task and reduced mixing and shifting costs in letter/number task-switching. However, this specific protocol type did not affect performance in tasks probing conflict monitoring and motor inhibition. Thus, our results suggest a modulation of proactive but not reactive mechanisms of cognitive control. In sum, the modulation of fm-theta via neurofeedback may serve as potent treatment approach for executive dysfunctions.

  12. Reward Expectancy Strengthens CA1 Theta and Beta Band Synchronization and Hippocampal-Ventral Striatal Coupling.

    Science.gov (United States)

    Lansink, Carien S; Meijer, Guido T; Lankelma, Jan V; Vinck, Martin A; Jackson, Jadin C; Pennartz, Cyriel M A

    2016-10-12

    The use of information from the hippocampal memory system in motivated behavior depends on its communication with the ventral striatum. When an animal encounters cues that signal subsequent reward, its reward expectancy is raised. It is unknown, however, how this process affects hippocampal dynamics and their influence on target structures, such as ventral striatum. We show that, in rats, reward-predictive cues result in enhanced hippocampal theta and beta band rhythmic activity during subsequent action, compared with uncued goal-directed navigation. The beta band component, also labeled theta's harmonic, involves selective hippocampal CA1 cell groups showing frequency doubling of firing periodicity relative to theta rhythmicity and it partitions the theta cycle into segments showing clear versus poor spike timing organization. We found that theta phase precession occurred over a wider range than previously reported. This was apparent from spikes emitted near the peak of the theta cycle exhibiting large "phase precessing jumps" relative to spikes in foregoing cycles. Neither this phenomenon nor the regular manifestation of theta phase precession was affected by reward expectancy. Ventral striatal neuronal firing phase-locked not only to hippocampal theta, but also to beta band activity. Both hippocampus and ventral striatum showed increased synchronization between neuronal firing and local field potential activity during cued compared with uncued goal approaches. These results suggest that cue-triggered reward expectancy intensifies hippocampal output to target structures, such as the ventral striatum, by which the hippocampus may gain prioritized access to systems modulating motivated behaviors. Here we show that temporally discrete cues raising reward expectancy enhance both theta and beta band activity in the hippocampus once goal-directed navigation has been initiated. These rhythmic activities are associated with increased synchronization of neuronal firing

  13. Theta-Gamma Coupling and Working Memory in Alzheimer’s Dementia and Mild Cognitive Impairment

    Directory of Open Access Journals (Sweden)

    Michelle S. Goodman

    2018-04-01

    Full Text Available Working memory deficits are common among individuals with Alzheimer’s dementia (AD or mild cognitive impairment (MCI. Yet, little is known about the mechanisms underlying these deficits. Theta-gamma coupling—the modulation of high-frequency gamma oscillations by low-frequency theta oscillations—is a neurophysiologic process underlying working memory. We assessed the relationship between theta-gamma coupling and working memory deficits in AD and MCI. We hypothesized that: (1 individuals with AD would display the most significant working memory impairments followed by MCI and finally healthy control (HC participants; and (2 there would be a significant association between working memory performance and theta-gamma coupling across all participants. Ninety-eight participants completed the N-back working memory task during an electroencephalography (EEG recording: 33 with AD (mean ± SD age: 76.5 ± 6.2, 34 with MCI (mean ± SD age: 74.8 ± 5.9 and 31 HCs (mean ± SD age: 73.5 ± 5.2. AD participants performed significantly worse than control and MCI participants on the 1- and 2-back conditions. Regarding theta-gamma coupling, AD participants demonstrated the lowest level of coupling followed by the MCI and finally control participants on the 2-back condition. Finally, a linear regression analysis demonstrated that theta-gamma coupling (β = 0.69, p < 0.001 was the most significant predictor of 2-back performance. Our results provide evidence for a relationship between altered theta-gamma coupling and working memory deficits in individuals with AD and MCI. They also provide insight into a potential mechanism underlying working memory impairments in these individuals.

  14. Modulation of Hippocampal Theta Oscillations and Spatial Memory by Relaxin-3 Neurons of the Nucleus Incertus

    Science.gov (United States)

    Ma, Sherie; Olucha-Bordonau, Francisco E.; Hossain, M. Akhter; Lin, Feng; Kuei, Chester; Liu, Changlu; Wade, John D.; Sutton, Steven W.; Nunez, Angel; Gundlach, Andrew L.

    2009-01-01

    Hippocampal theta rhythm is thought to underlie learning and memory, and it is well established that "pacemaker" neurons in medial septum (MS) modulate theta activity. Recent studies in the rat demonstrated that brainstem-generated theta rhythm occurs through a multisynaptic pathway via the nucleus incertus (NI), which is the primary source of the…

  15. Computational study of hippocampal-septal theta rhythm changes due to β-amyloid-altered ionic channels.

    Directory of Open Access Journals (Sweden)

    Xin Zou

    Full Text Available Electroencephagraphy (EEG of many dementia patients has been characterized by an increase in low frequency field potential oscillations. One of the characteristics of early stage Alzheimer's disease (AD is an increase in theta band power (4-7 Hz. However, the mechanism(s underlying the changes in theta oscillations are still unclear. To address this issue, we investigate the theta band power changes associated with β-Amyloid (Aβ peptide (one of the main markers of AD using a computational model, and by mediating the toxicity of hippocampal pyramidal neurons. We use an established biophysical hippocampal CA1-medial septum network model to evaluate four ionic channels in pyramidal neurons, which were demonstrated to be affected by Aβ. They are the L-type Ca²⁺ channel, delayed rectifying K⁺ channel, A-type fast-inactivating K⁺ channel and large-conductance Ca²⁺-activated K⁺ channel. Our simulation results demonstrate that only the Aβ inhibited A-type fast-inactivating K⁺ channel can induce an increase in hippocampo-septal theta band power, while the other channels do not affect theta rhythm. We further deduce that this increased theta band power is due to enhanced synchrony of the pyramidal neurons. Our research may elucidate potential biomarkers and therapeutics for AD. Further investigation will be helpful for better understanding of AD-induced theta rhythm abnormalities and associated cognitive deficits.

  16. Theta oscillations at encoding mediate the context-dependent nature of human episodic memory.

    Science.gov (United States)

    Staudigl, Tobias; Hanslmayr, Simon

    2013-06-17

    Human episodic memory is highly context dependent. Therefore, retrieval benefits when a memory is recalled in the same context compared to a different context. This implies that items and contexts are bound together during encoding, such that the reinstatement of the initial context at test improves retrieval. Animal studies suggest that theta oscillations and theta-to-gamma cross-frequency coupling modulate such item-context binding, but direct evidence from humans is scarce. We investigated this issue by manipulating the overlap of contextual features between encoding and retrieval. Participants studied words superimposed on movie clips and were later tested by presenting the word with either the same or a different movie. The results show that memory performance and the oscillatory correlates of memory formation crucially depend on the overlap of the context between encoding and test. When the context matched, high theta power during encoding was related to successful recognition, whereas the opposite pattern emerged in the context-mismatch condition. In addition, cross-frequency coupling analysis revealed a context-dependent theta-to-gamma memory effect specifically in the left hippocampus. These results reveal for the first time that context-dependent episodic memory effects are mediated by theta oscillatory activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Donaldson-Witten theory and indefinite theta functions

    Science.gov (United States)

    Korpas, Georgios; Manschot, Jan

    2017-11-01

    We consider partition functions with insertions of surface operators of topologically twisted N=2 , SU(2) supersymmetric Yang-Mills theory, or Donaldson-Witten theory for short, on a four-manifold. If the metric of the compact four-manifold has positive scalar curvature, Moore and Witten have shown that the partition function is completely determined by the integral over the Coulomb branch parameter a, while more generally the Coulomb branch integral captures the wall-crossing behavior of both Donaldson polynomials and Seiberg-Witten invariants. We show that after addition of a \\overlineQ -exact surface operator to the Moore-Witten integrand, the integrand can be written as a total derivative to the anti-holomorphic coordinate ā using Zwegers' indefinite theta functions. In this way, we reproduce Göttsche's expressions for Donaldson invariants of rational surfaces in terms of indefinite theta functions for any choice of metric.

  18. Biologically based machine vision: signal analysis of monopolar cells in the visual system of Musca domestica.

    Science.gov (United States)

    Newton, Jenny; Barrett, Steven F; Wilcox, Michael J; Popp, Stephanie

    2002-01-01

    Machine vision for navigational purposes is a rapidly growing field. Many abilities such as object recognition and target tracking rely on vision. Autonomous vehicles must be able to navigate in dynamic enviroments and simultaneously locate a target position. Traditional machine vision often fails to react in real time because of large computational requirements whereas the fly achieves complex orientation and navigation with a relatively small and simple brain. Understanding how the fly extracts visual information and how neurons encode and process information could lead us to a new approach for machine vision applications. Photoreceptors in the Musca domestica eye that share the same spatial information converge into a structure called the cartridge. The cartridge consists of the photoreceptor axon terminals and monopolar cells L1, L2, and L4. It is thought that L1 and L2 cells encode edge related information relative to a single cartridge. These cells are thought to be equivalent to vertebrate bipolar cells, producing contrast enhancement and reduction of information sent to L4. Monopolar cell L4 is thought to perform image segmentation on the information input from L1 and L2 and also enhance edge detection. A mesh of interconnected L4's would correlate the output from L1 and L2 cells of adjacent cartridges and provide a parallel network for segmenting an object's edges. The focus of this research is to excite photoreceptors of the common housefly, Musca domestica, with different visual patterns. The electrical response of monopolar cells L1, L2, and L4 will be recorded using intracellular recording techniques. Signal analysis will determine the neurocircuitry to detect and segment images.

  19. Double Chooz and non Asian efforts towards {theta}{sub 13}

    Energy Technology Data Exchange (ETDEWEB)

    Lasserre, Thierry [CEA/Saclay and Laboratoire Astroparticle and Cosmologie Institut de Recherche des Lois Fondamentales de l' Univers Service de Physique des Particules 91191 Gif-s-Yvette (France)], E-mail: thierry.lasserre@cea.fr

    2008-11-01

    Neutrino oscillation physics is entering a precision measurement area. The smallness of the {theta}{sub 13} neutrino mixing angle is still enigmatic and should be resolved. Double Chooz will use two identical detectors near the Chooz nuclear power station to search for a non vanishing {theta}{sub 13}, and hopefully open the way to experiments aspiring to discover CP violation in the leptonic sector. The Angra project aims to prevail over the Double Chooz experiment if the third neutrino oscillation channel is not discovered in the forthcoming years.

  20. Study on creep behavior of Grade 91 heat-resistant steel using theta projection method

    Science.gov (United States)

    Ren, Facai; Tang, Xiaoying

    2017-10-01

    Creep behavior of Grade 91 heat-resistant steel used for steam cooler was characterized using the theta projection method. Creep tests were conducted at the temperature of 923K under the stress ranging from 100-150MPa. Based on the creep curve results, four theta parameters were established using a nonlinear least square fitting method. Four theta parameters showed a good linearity as a function of stress. The predicted curves coincided well with the experimental data and creep curves were also modeled to the low stress level of 60MPa.

  1. Episodic sequence memory is supported by a theta-gamma phase code.

    Science.gov (United States)

    Heusser, Andrew C; Poeppel, David; Ezzyat, Youssef; Davachi, Lila

    2016-10-01

    The meaning we derive from our experiences is not a simple static extraction of the elements but is largely based on the order in which those elements occur. Models propose that sequence encoding is supported by interactions between high- and low-frequency oscillations, such that elements within an experience are represented by neural cell assemblies firing at higher frequencies (gamma) and sequential order is encoded by the specific timing of firing with respect to a lower frequency oscillation (theta). During episodic sequence memory formation in humans, we provide evidence that items in different sequence positions exhibit greater gamma power along distinct phases of a theta oscillation. Furthermore, this segregation is related to successful temporal order memory. Our results provide compelling evidence that memory for order, a core component of an episodic memory, capitalizes on the ubiquitous physiological mechanism of theta-gamma phase-amplitude coupling.

  2. Statistical properties of multi-theta polymer chains

    Science.gov (United States)

    Uehara, Erica; Deguchi, Tetsuo

    2018-04-01

    We study statistical properties of polymer chains with complex structures whose chemical connectivities are expressed by graphs. The multi-theta curve of m subchains with two branch points connected by them is one of the simplest graphs among those graphs having closed paths, i.e. loops. We denoted it by θm , and for m  =  2 it is given by a ring. We derive analytically the pair distribution function and the scattering function for the θm -shaped polymer chains consisting of m Gaussian random walks of n steps. Surprisingly, it is shown rigorously that the mean-square radius of gyration for the Gaussian θm -shaped polymer chain does not depend on the number m of subchains if each subchain has the same fixed number of steps. For m  =  3 we show the Kratky plot for the theta-shaped polymer chain consisting of hard cylindrical segments by the Monte-Carlo method including reflection at trivalent vertices.

  3. Development of Supputius cincticeps (Heteroptera, Pentatomidae) fed with Zophobas confusa, Tenebrio molitor (Coleoptera, Tenebrionidae) and Musca domestica (Diptera, Muscidae) larvae

    OpenAIRE

    Beserra, Eduardo B.; Zanuncio, Teresinha V.; Zanuncio, José C.; Santos, Germi P.

    1995-01-01

    Egg viability and nymphal development of the predatory bug Supputius cincticeps (Stål, 1860) were evaluated during two generations in the Biological Control Laboratory of the Núcleo de Biotecnologia Aplicada à Agropecuária (Bioagro/UFV) in Viçosa (Minas Gerais, Brazil) at 24.72±1.10ºC and photophase of 12 hours. Three treatments were represented by S. cincticeps fed with Zophobas confusa Gebien, 1906, Tenebrio molitor Linnaeus, 1758 and Musca domestica Linnaeus, 1758 larvae. Higher egg viabil...

  4. Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory.

    Science.gov (United States)

    Kawasaki, Masahiro; Kitajo, Keiichi; Yamaguchi, Yoko

    2014-01-01

    In humans, theta phase (4-8 Hz) synchronization observed on electroencephalography (EEG) plays an important role in the manipulation of mental representations during working memory (WM) tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from subjects who were performing auditory-verbal and visual WM tasks; we compared the theta synchronizations when subjects performed either auditory-verbal or visual manipulations in separate WM tasks, or performed both two manipulations in the same WM task. The auditory-verbal WM task required subjects to calculate numbers presented by an auditory-verbal stimulus, whereas the visual WM task required subjects to move a spatial location in a mental representation in response to a visual stimulus. The dual WM task required subjects to manipulate auditory-verbal, visual, or both auditory-verbal and visual representations while maintaining auditory-verbal and visual representations. Our time-frequency EEG analyses revealed significant fronto-temporal theta phase synchronization during auditory-verbal manipulation in both auditory-verbal and auditory-verbal/visual WM tasks, but not during visual manipulation tasks. Similarly, we observed significant fronto-parietal theta phase synchronization during visual manipulation tasks, but not during auditory-verbal manipulation tasks. Moreover, we observed significant synchronization in both the fronto-temporal and fronto-parietal theta signals during simultaneous auditory-verbal/visual manipulations. These findings suggest that theta synchronization seems to flexibly connect the brain areas that manipulate WM.

  5. Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory

    Directory of Open Access Journals (Sweden)

    Masahiro eKawasaki

    2014-03-01

    Full Text Available In humans, theta phase (4–8 Hz synchronization observed on electroencephalography (EEG plays an important role in the manipulation of mental representations during working memory (WM tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from subjects who were performing auditory-verbal and visual WM tasks; we compared the theta synchronizations when subjects performed either auditory-verbal or visual manipulations in separate WM tasks, or performed both two manipulations in the same WM task. The auditory-verbal WM task required subjects to calculate numbers presented by an auditory-verbal stimulus, whereas the visual WM task required subjects to move a spatial location in a mental representation in response to a visual stimulus. The dual WM task required subjects to manipulate auditory-verbal, visual, or both auditory-verbal and visual representations while maintaining auditory-verbal and visual representations. Our time-frequency EEG analyses revealed significant fronto-temporal theta phase synchronization during auditory-verbal manipulation in both auditory-verbal and auditory-verbal/visual WM tasks, but not during visual manipulation tasks. Similarly, we observed significant fronto-parietal theta phase synchronization during visual manipulation tasks, but not during auditory-verbal manipulation tasks. Moreover, we observed significant synchronization in both the fronto-temporal and fronto-parietal theta signals during simultaneous auditory-verbal/visual manipulations. These findings suggest that theta synchronization seems to flexibly connect the brain areas that manipulate WM.

  6. Effects of intermittent theta burst stimulation on cerebral blood flow and cerebral vasomotor reactivity.

    Science.gov (United States)

    Pichiorri, Floriana; Vicenzini, Edoardo; Gilio, Francesca; Giacomelli, Elena; Frasca, Vittorio; Cambieri, Chiara; Ceccanti, Marco; Di Piero, Vittorio; Inghilleri, Maurizio

    2012-08-01

    To determine whether intermittent theta burst stimulation influences cerebral hemodynamics, we investigated changes induced by intermittent theta burst stimulation on the middle cerebral artery cerebral blood flow velocity and vasomotor reactivity to carbon dioxide (CO(2)) in healthy participants. The middle cerebral artery flow velocity and vasomotor reactivity were monitored by continuous transcranial Doppler sonography. Changes in cortical excitability were tested by transcranial magnetic stimulation. In 11 healthy participants, before and immediately after delivering intermittent theta burst stimulation, we tested cortical excitability measured by the resting motor threshold and motor evoked potential amplitude over the stimulated hemisphere and vasomotor reactivity to CO(2) bilaterally. The blood flow velocity was monitored in both middle cerebral arteries throughout the experimental session. In a separate session, we tested the effects of sham stimulation under the same experimental conditions. Whereas the resting motor threshold remained unchanged before and after stimulation, motor evoked potential amplitudes increased significantly (P = .04). During and after stimulation, middle cerebral artery blood flow velocities also remained bilaterally unchanged, whereas vasomotor reactivity to CO(2) increased bilaterally (P = .04). The sham stimulation left all variables unchanged. The expected intermittent theta burst stimulation-induced changes in cortical excitability were not accompanied by changes in cerebral blood flow velocities; however, the bilateral increased vasomotor reactivity suggests that intermittent theta burst stimulation influences the cerebral microcirculation, possibly involving subcortical structures. These findings provide useful information on hemodynamic phenomena accompanying intermittent theta burst stimulation, which should be considered in research aimed at developing this noninvasive, low-intensity stimulation technique for safe

  7. The small mixing angle $\\theta_{13}$ and the lepton asymmetry

    CERN Document Server

    Lee, S H; Lee, Song-Haeng; Siyeon, Kim

    2005-01-01

    We present the correlation of low energy CP phases, both Dirac and Majorana, and the lepton asymmetry for the baryon asymmetry in the universe, with a certain class of Yukawa matrices that consist of two right-handed neutrinos and include one texture zero in themselves. For cases in which the amount of the lepton asymmetry $Y_L$ turns out to be proportional to $\\theta_{13}^2$, we consider the relation between two types of CP phases and the relation of $Y_L$ versus the Jarlskog invariant or the amplitude of neutrinoless double beta decay as $\\theta_{13}$ varies.

  8. Theta signal as the neural signature of social exclusion.

    Science.gov (United States)

    Cristofori, Irene; Moretti, Laura; Harquel, Sylvain; Posada, Andres; Deiana, Gianluca; Isnard, Jean; Mauguière, François; Sirigu, Angela

    2013-10-01

    The feeling of being excluded from a social interaction triggers social pain, a sensation as intense as actual physical pain. Little is known about the neurophysiological underpinnings of social pain. We addressed this issue using intracranial electroencephalography in 15 patients performing a ball game where inclusion and exclusion blocks were alternated. Time-frequency analyses showed an increase in power of theta-band oscillations during exclusion in the anterior insula (AI) and posterior insula, the subgenual anterior cingulate cortex (sACC), and the fusiform "face area" (FFA). Interestingly, the AI showed an initial fast response to exclusion but the signal rapidly faded out. Activity in the sACC gradually increased and remained significant thereafter. This suggests that the AI may signal social pain by detecting emotional distress caused by the exclusion, whereas the sACC may be linked to the learning aspects of social pain. Theta activity in the FFA was time-locked to the observation of a player poised to exclude the participant, suggesting that the FFA encodes the social value of faces. Taken together, our findings suggest that theta activity represents the neural signature of social pain. The time course of this signal varies across regions important for processing emotional features linked to social information.

  9. Cueing vocabulary during sleep increases theta activity during later recognition testing.

    Science.gov (United States)

    Schreiner, Thomas; Göldi, Maurice; Rasch, Björn

    2015-11-01

    Neural oscillations in the theta band have repeatedly been implicated in successful memory encoding and retrieval. Several recent studies have shown that memory retrieval can be facilitated by reactivating memories during their consolidation during sleep. However, it is still unknown whether reactivation during sleep also enhances subsequent retrieval-related neural oscillations. We have recently demonstrated that foreign vocabulary cues presented during sleep improve later recall of the associated translations. Here, we examined the effect of cueing foreign vocabulary during sleep on oscillatory activity during subsequent recognition testing after sleep. We show that those words that were replayed during sleep after learning (cued words) elicited stronger centroparietal theta activity during recognition as compared to noncued words. The reactivation-induced increase in theta oscillations during later recognition testing might reflect a strengthening of individual memory traces and the integration of the newly learned words into the mental lexicon by cueing during sleep. © 2015 Society for Psychophysiological Research.

  10. Increase in short-term memory capacity induced by down-regulating individual theta frequency via transcranial alternating current stimulation.

    Science.gov (United States)

    Vosskuhl, Johannes; Huster, René J; Herrmann, Christoph S

    2015-01-01

    Working memory (WM) and short-term memory (STM) supposedly rely on the phase-amplitude coupling (PAC) of neural oscillations in the theta and gamma frequency ranges. The ratio between the individually dominant gamma and theta frequencies is believed to determine an individual's memory capacity. The aim of this study was to establish a causal relationship between the gamma/theta ratio and WM/STM capacity by means of transcranial alternating current stimulation (tACS). To achieve this, tACS was delivered at a frequency below the individual theta frequency. Thereby the individual ratio of gamma to theta frequencies was changed, resulting in an increase of STM capacity. Healthy human participants (N = 33) were allocated to two groups, one receiving verum tACS, the other underwent a sham control protocol. The electroencephalogram (EEG) was measured before stimulation and analyzed with regard to the properties of PAC between theta and gamma frequencies to determine individual stimulation frequencies. After stimulation, EEG was recorded again in order to find after-effects of tACS in the oscillatory features of the EEG. Measures of STM and WM were obtained before, during and after stimulation. Frequency spectra and behavioral data were compared between groups and different measurement phases. The tACS- but not the sham stimulated group showed an increase in STM capacity during stimulation. WM was not affected in either groups. An increase in task-related theta amplitude after stimulation was observed only for the tACS group. These augmented theta amplitudes indicated that the manipulation of individual theta frequencies was successful and caused the increase in STM capacity.

  11. Size relationships of different body parts in the three dipteran species Drosophila melanogaster, Ceratitis capitata and Musca domestica.

    Science.gov (United States)

    Siomava, Natalia; Wimmer, Ernst A; Posnien, Nico

    2016-06-01

    Body size is an integral feature of an organism that influences many aspects of life such as fecundity, life span and mating success. Size of individual organs and the entire body size represent quantitative traits with a large reaction norm, which are influenced by various environmental factors. In the model system Drosophila melanogaster, pupal size and adult traits, such as tibia and thorax length or wing size, accurately estimate the overall body size. However, it is unclear whether these traits can be used in other flies. Therefore, we studied changes in size of pupae and adult organs in response to different rearing temperatures and densities for D. melanogaster, Ceratitis capitata and Musca domestica. We confirm a clear sexual size dimorphism (SSD) for Drosophila and show that the SSD is less uniform in the other species. Moreover, the size response to changing growth conditions is sex dependent. Comparison of static and evolutionary allometries of the studied traits revealed that response to the same environmental variable is genotype specific but has similarities between species of the same order. We conclude that the value of adult traits as estimators of the absolute body size may differ among species and the use of a single trait may result in wrong assumptions. Therefore, we suggest using a body size coefficient computed from several individual measurements. Our data is of special importance for monitoring activities of natural populations of the three dipteran flies, since they are harmful species causing economical damage (Drosophila, Ceratitis) or transferring diseases (Musca).

  12. Hippocampal theta frequency shifts and operant behaviour

    NARCIS (Netherlands)

    Lopes da Silva, F.H.; Kamp, A.

    1. 1. A shift of hippocampal dominant theta frequency to 6 c/sec has been demonstrated in the post-reward period in two dogs, which occurs consistently related in time to a well defined behavioural pattern in the course of an operant conditioning paradigm. 2. 2. The frequency shift was detected and

  13. The effects of sex-ratio and density on locomotor activity in the house fly, Musca domestica

    DEFF Research Database (Denmark)

    Bahrndorff, Simon; Kjaersgaard, Anders; Pertoldi, Cino

    2012-01-01

    Although locomotor activity is involved in almost all behavioral traits, there is a lack of knowledge on what factors affect it. This study examined the effects of sex-ratio and density on the circadian rhythm of locomotor activity of adult Musca domestica L. (Diptera: Muscidae) using an infra......-red light system. Sex-ratio significantly affected locomotor activity, increasing with the percentage of males in the vials. In accordance with other studies, males were more active than females, but the circadian rhythm of the two sexes was not constant over time and changed during the light period...... of the behavioral interactions between houseflies and highlight the importance of these factors when designing behavioral experiments using M. domestica....

  14. A Randomized Trial of Comparing the Efficacy of Two Neurofeedback Protocols for Treatment of Clinical and Cognitive Symptoms of ADHD: Theta Suppression/Beta Enhancement and Theta Suppression/Alpha Enhancement

    Directory of Open Access Journals (Sweden)

    Arash Mohagheghi

    2017-01-01

    Full Text Available Introduction. Neurofeedback (NF is an adjuvant or alternative therapy for children with Attention Deficit Hyperactivity Disorder (ADHD. This study intended to compare the efficacy of two different NF protocols on clinical and cognitive symptoms of ADHD. Materials and Methods. In this clinical trial, sixty children with ADHD aged 7 to 10 years old were randomly grouped to receive two different NF treatments (theta suppression/beta enhancement protocol and theta suppression/alpha enhancement protocol. Clinical and cognitive assessments were conducted prior to and following the treatment and also after an eight-week follow-up. Results. Both protocols alleviated the symptoms of ADHD in general (p<0.001, hyperactivity (p<0.001, inattention (p<0.001, and omission errors (p<0.001; however, they did not affect the oppositional and impulsive scales nor commission errors. These effects were maintained after an eight-week intervention-free period. The only significant difference between the two NF protocols was that high-frequency alpha enhancement protocol performed better in suppressing omission errors (p<0.001. Conclusion. The two NF protocols with theta suppression/beta enhancement and theta suppression/alpha enhancement have considerable and comparable effect on clinical symptoms of ADHD. Alpha enhancement protocol was more effective in suppressing omission errors.

  15. Increase in short-term memory capacity induced by down-regulating individual theta frequency via transcranial alternating current stimulation

    Directory of Open Access Journals (Sweden)

    Johannes eVosskuhl

    2015-05-01

    Full Text Available Working memory (WM and short-term memory (STM supposedly rely on the phase-amplitude coupling of neural oscillations in the theta and gamma frequency ranges. The ratio between the individually dominant gamma and theta frequencies is believed to determine an individual’s memory capacity. The aim of this study was to establish a causal relationship between the gamma/theta ratio and WM/STM capacity by means of transcranial alternating current stimulation (tACS. To achieve this, tACS was delivered at a frequency below the individual theta frequency. Thereby the individual ratio of gamma to theta frequencies was changed, resulting in an increase of STM capacity. Healthy human participants (N=33 were allocated to two groups, one receiving verum tACS, the other underwent a sham control protocol. The electroencephalogram (EEG was measured before stimulation and analyzed with regard to the properties of phase-amplitude coupling between theta and gamma frequencies to determine individual stimulation frequencies. After stimulation, EEG was recorded again in order to find after-effects of tACS in the oscillatory features of the EEG. Measures of STM and WM were obtained before, during and after stimulation. Frequency spectra and behavioral data were compared between groups and different measurement phases. The tACS- but not the sham stimulated group showed an increase in STM capacity during stimulation. WM was not affected in either groups. An increase in task-related theta amplitude after stimulation was observed only for the tACS group. These augmented theta amplitudes indicated that the manipulation of individual theta frequencies was successful and caused the increase in STM capacity.

  16. On the irrationality of Ramanujan's mock theta functions and other q-series at an infinite number of points

    OpenAIRE

    Mingarelli, Angelo B.

    2007-01-01

    We show that all of Ramanujan's mock theta functions of order 3, Watson's three additional mock theta functions of order 3, the Rogers-Ramanujan q-series, and 6 mock theta functions of order 5 take on irrational values at the points q=\\pm 1/2,\\pm 1/3,\\pm 1/4,...

  17. Material testing in a linear theta pinch

    International Nuclear Information System (INIS)

    Alani, R.; Azodi, H.; Naraghi, M.; Safaii, B.; Torabi-Fard, A.

    1983-01-01

    The interaction of stainless steel 316 and Inconel 625 alloys has been investigated with a thermonuclear-like plasma, n = 10 16 cm -3 and Tsub(i) = 1 keV, generated in the Alvand I linear theta pinch. The average power flux is 10 7 W/cm 2 and the interaction time nearly one μs. A theoretical analysis based on the formation of an observed impurity layer near the material, has been used to determine the properties of the impurity layer and the extent of the damage on the material. Although arcing has been observed, the dominant damage mechanism has been assessed to be due to evaporation. Exposure to single shots has produced very heavily defective areas and even surface cracks on the SS 316 sample, but no cracks were observed on Inconel 625 after exposure to even 18 shots. On the basis of temperature rise and evaporation a comparison is made among materials exposed to plasmas of a theta pinch, shock tube, present generation tokamak and an anticipated tokamak reactor. (orig.)

  18. Theta oscillations during holeboard training in rats: different learning strategies entail different context-dependent modulations in the hippocampus.

    Science.gov (United States)

    Woldeit, M L; Korz, V

    2010-02-03

    A functional connection between theta rhythms, information processing, learning and memory formation is well documented by studies focusing on the impact of theta waves on motor activity, global context or phase coding in spatial learning. In the present study we analyzed theta oscillations during a spatial learning task and assessed which specific behavioral contexts were connected to changes in theta power and to the formation of memory. Therefore, we measured hippocampal dentate gyrus theta modulations in male rats that were allowed to establish a long-term spatial reference memory in a holeboard (fixed pattern of baited holes) in comparison to rats that underwent similar training conditions but could not form a reference memory (randomly baited holes). The first group established a pattern specific learning strategy, while the second developed an arbitrary search strategy, visiting increasingly more holes during training. Theta power was equally influenced during the training course in both groups, but was significantly higher when compared to untrained controls. A detailed behavioral analysis, however, revealed behavior- and context-specific differences within the experimental groups. In spatially trained animals theta power correlated with the amounts of reference memory errors in the context of the inspection of unbaited holes and exploration in which, as suggested by time frequency analyses, also slow wave (delta) power was increased. In contrast, in randomly trained animals positive correlations with working memory errors were found in the context of rearing behavior. These findings indicate a contribution of theta/delta to long-lasting memory formation in spatially trained animals, whereas in pseudo trained animals theta seems to be related to attention in order to establish trial specific short-term working memory. Implications for differences in neuronal plasticity found in earlier studies are discussed. Copyright 2010 IBRO. Published by Elsevier Ltd

  19. Coupling between Theta Oscillations and Cognitive Control Network during Cross-Modal Visual and Auditory Attention: Supramodal vs Modality-Specific Mechanisms.

    Science.gov (United States)

    Wang, Wuyi; Viswanathan, Shivakumar; Lee, Taraz; Grafton, Scott T

    2016-01-01

    Cortical theta band oscillations (4-8 Hz) in EEG signals have been shown to be important for a variety of different cognitive control operations in visual attention paradigms. However the synchronization source of these signals as defined by fMRI BOLD activity and the extent to which theta oscillations play a role in multimodal attention remains unknown. Here we investigated the extent to which cross-modal visual and auditory attention impacts theta oscillations. Using a simultaneous EEG-fMRI paradigm, healthy human participants performed an attentional vigilance task with six cross-modal conditions using naturalistic stimuli. To assess supramodal mechanisms, modulation of theta oscillation amplitude for attention to either visual or auditory stimuli was correlated with BOLD activity by conjunction analysis. Negative correlation was localized to cortical regions associated with the default mode network and positively with ventral premotor areas. Modality-associated attention to visual stimuli was marked by a positive correlation of theta and BOLD activity in fronto-parietal area that was not observed in the auditory condition. A positive correlation of theta and BOLD activity was observed in auditory cortex, while a negative correlation of theta and BOLD activity was observed in visual cortex during auditory attention. The data support a supramodal interaction of theta activity with of DMN function, and modality-associated processes within fronto-parietal networks related to top-down theta related cognitive control in cross-modal visual attention. On the other hand, in sensory cortices there are opposing effects of theta activity during cross-modal auditory attention.

  20. Combinatorial identities for tenth order mock theta functions

    Indian Academy of Sciences (India)

    44

    which lead us to one 4-way and one 3-way combinatorial identity. ... mock theta functions, partition identities and different combinatorial parameters, see for ... 3. Example 1.1. There are twelve (n + 1)–color partitions of 2: 21, 21 + 01, 11 + 11, ...

  1. Multifractal Detrended Fluctuation Analysis of alpha and theta EEG rhythms with musical stimuli

    International Nuclear Information System (INIS)

    Maity, Akash Kumar; Pratihar, Ruchira; Mitra, Anubrato; Dey, Subham; Agrawal, Vishal; Sanyal, Shankha; Banerjee, Archi; Sengupta, Ranjan; Ghosh, Dipak

    2015-01-01

    Highlights: • EEG was done to record the brain electrical activity of 10 subjects in response to simple acoustical tanpura stimuli. • Empirical Mode Decomposition (EMD) technique used to make the EEG signal free from blink and other muscular artifacts. • Multifractal Detrended Fluctuation Analysis (MFDFA) performed to assess the complexity of extracted alpha and theta brain rhythms. • The findings show spectral width i.e. complexity of alpha and theta rhythms increase in all the seven frontal locations studied, under the effect of musical stimuli. - Abstract: Electroencephalography (EEG) was performed on 10 participants using a simple acoustical stimuli i.e. a tanpura drone. The tanpura drone is free from any semantic content and is used with a hypothesis that it provides a specific resting environment for the listeners. The EEG data was extracted for all the frontal electrodes viz. F3, F4, F7, F8, Fp1, Fp2 and Fz. Empirical Mode Decomposition (EMD) was applied on the acquired raw EEG signal to make it free from blink as well as other muscular artifacts. Wavelet Transform (WT) technique was used to segregate alpha and theta waves from the denoised EEG signal. Non-linear analysis in the form of Multifractal Detrended Fluctuation Analysis (MFDFA) was carried out on the extracted alpha and theta time series data to study the variation of their complexity. It was found that in all the frontal electrodes alpha as well as theta complexity increases as is evident from the increase of multifractal spectral width. This study is entirely new and gives interesting data regarding neural activation of the alpha and theta brain rhythms while listening to simple acoustical stimuli. The importance of this study lies in the context of emotion quantification using multifractal spectral width as a parameter as well as in the field of cognitive music therapy. The results are discussed in detail.

  2. Ramanujan’s mock theta functions

    Science.gov (United States)

    Griffin, Michael; Ono, Ken; Rolen, Larry

    2013-01-01

    In his famous deathbed letter, Ramanujan introduced the notion of a mock theta function, and he offered some alleged examples. Recent work by Zwegers [Zwegers S (2001) Contemp Math 291:268–277 and Zwegers S (2002) PhD thesis (Univ of Utrecht, Utrecht, The Netherlands)] has elucidated the theory encompassing these examples. They are holomorphic parts of special harmonic weak Maass forms. Despite this understanding, little attention has been given to Ramanujan’s original definition. Here, we prove that Ramanujan’s examples do indeed satisfy his original definition. PMID:23536292

  3. Genetic variability in the human cannabinoid receptor 1 is associated with resting state EEG theta power in humans.

    Science.gov (United States)

    Heitland, I; Kenemans, J L; Böcker, K B E; Baas, J M P

    2014-11-01

    It has long been postulated that exogenous cannabinoids have a profound effect on human cognitive functioning. These cannabinoid effects are thought to depend, at least in parts, on alterations of phase-locking of local field potential neuronal firing. The latter can be measured as activity in the theta frequency band (4-7Hz) by electroencephalogram. Theta oscillations are supposed to serve as a mechanism in neural representations of behaviorally relevant information. However, it remains unknown whether variability in endogenous cannabinoid activity is involved in theta rhythms and therefore, may serve as an individual differences index of human cognitive functioning. To clarify this issue, we recorded resting state EEG activity in 164 healthy human subjects and extracted EEG power across frequency bands (δ, θ, α, and β). To assess variability in the endocannabinoid system, two genetic polymorphisms (rs1049353, rs2180619) within the cannabinoid receptor 1 (CB1) were determined in all participants. As expected, we observed significant effects of rs1049353 on EEG power in the theta band at frontal, central and parietal electrode regions. Crucially, these effects were specific for the theta band, with no effects on activity in the other frequency bands. Rs2180619 showed no significant associations with theta power after Bonferroni correction. Taken together, we provide novel evidence in humans showing that genetic variability in the cannabinoid receptor 1 is associated with resting state EEG power in the theta frequency band. This extends prior findings of exogenous cannabinoid effects on theta power to the endogenous cannabinoid system. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Interacting binaries

    International Nuclear Information System (INIS)

    Eggleton, P.P.; Pringle, J.E.

    1985-01-01

    This volume contains 15 review articles in the field of binary stars. The subjects reviewed span considerably, from the shortest period of interacting binaries to the longest, symbiotic stars. Also included are articles on Algols, X-ray binaries and Wolf-Rayet stars (single and binary). Contents: Preface. List of Participants. Activity of Contact Binary Systems. Wolf-Rayet Stars and Binarity. Symbiotic Stars. Massive X-ray Binaries. Stars that go Hump in the Night: The SU UMa Stars. Interacting Binaries - Summing Up

  5. High precision measurement of sin2theta/sub W/ in semi-leptonic neutrino interactions

    International Nuclear Information System (INIS)

    Guyot, C.

    1985-01-01

    The experiment has provided what is presently the most accurate measurement of sin 2 theta/sub W/. The errors are still too large for a significant test of the standard model and the measured value is in agreement with the measured values of M/sub W/ and M/sub Z/. On the other hand, this result can constrain the Grand Unified models. The standard SU(5) model predicts sin 2 theta/sub W//sup MS/ = 0.214 +/- 0.004 (the error comes from the uncertainty on Lambda/sub MS/), in very good agreement with the measured value. While this model has big problems with the proton lifetime, it could be saved by its supersymmetric extension. In the minimal SU(5) SUSY model (with 2 Higgs supermultiplets) sin 2 theta/sub W//sup MS/ = 0.233 +/- 0.004, [12] in bad agreement with the measured value. The addition of other Higgs supermultiplets increases the value of sin 2 theta/sub W/. Unless some unexpected large contribution from higher-twist terms occurs, the present measurement can already bring a significant constraint on Grand Unified models

  6. Resolution improvement by nonconfocal theta microscopy.

    Science.gov (United States)

    Lindek, S; Stelzer, E H

    1999-11-01

    We present a novel scanning fluorescence microscopy technique, nonconfocal theta microscopy (NCTM), that provides almost isotropic resolution. In NCTM, multiphoton absorption from two orthogonal illumination directions is used to induce fluorescence emission. Therefore the point-spread function of the microscope is described by the product of illumination point-spread functions with reduced spatial overlap, which provides the resolution improvement and the more isotropic observation volume. We discuss the technical details of this new method.

  7. Different types of theta rhythmicity are induced by social and fearful stimuli in a network associated with social memory.

    Science.gov (United States)

    Tendler, Alex; Wagner, Shlomo

    2015-02-16

    Rhythmic activity in the theta range is thought to promote neuronal communication between brain regions. In this study, we performed chronic telemetric recordings in socially behaving rats to monitor electrophysiological activity in limbic brain regions linked to social behavior. Social encounters were associated with increased rhythmicity in the high theta range (7-10 Hz) that was proportional to the stimulus degree of novelty. This modulation of theta rhythmicity, which was specific for social stimuli, appeared to reflect a brain-state of social arousal. In contrast, the same network responded to a fearful stimulus by enhancement of rhythmicity in the low theta range (3-7 Hz). Moreover, theta rhythmicity showed different pattern of coherence between the distinct brain regions in response to social and fearful stimuli. We suggest that the two types of stimuli induce distinct arousal states that elicit different patterns of theta rhythmicity, which cause the same brain areas to communicate in different modes.

  8. Semantic congruence enhances memory of episodic associations: role of theta oscillations.

    Science.gov (United States)

    Atienza, Mercedes; Crespo-Garcia, Maite; Cantero, Jose L

    2011-01-01

    Growing evidence suggests that theta oscillations play a crucial role in episodic encoding. The present study evaluates whether changes in electroencephalographic theta source dynamics mediate the positive influence of semantic congruence on incidental associative learning. Here we show that memory for episodic associations (face-location) is more accurate when studied under semantically congruent contexts. However, only participants showing RT priming effect in a conceptual priming test (priming group) also gave faster responses when recollecting source information of semantically congruent faces as compared with semantically incongruent faces. This improved episodic retrieval was positively correlated with increases in theta power during the study phase mainly in the bilateral parahippocampal gyrus, left superior temporal gyrus, and left lateral posterior parietal lobe. Reconstructed signals from the estimated sources showed higher theta power for congruent than incongruent faces and also for the priming than the nonpriming group. These results are in agreement with the attention to memory model. Besides directing top-down attention to goal-relevant semantic information during encoding, the dorsal parietal lobe may also be involved in redirecting attention to bottom-up-driven memories thanks to connections between the medial-temporal and the left ventral parietal lobe. The latter function can either facilitate or interfere with encoding of face-location associations depending on whether they are preceded by semantically congruent or incongruent contexts, respectively, because only in the former condition retrieved representations related to the cue and the face are both coherent with the person identity and are both associated with the same location.

  9. Alcohol Hits You When It Is Hard: Intoxication, Task Difficulty, and Theta Brain Oscillations.

    Science.gov (United States)

    Rosen, Burke Q; Padovan, Nevena; Marinkovic, Ksenija

    2016-04-01

    Alcohol intoxication is known to impair decision making in a variety of situations. Previous neuroimaging evidence suggests that the neurofunctional system subserving controlled processing is especially vulnerable to alcohol in conflict-evoking tasks. The present study investigated the effects of moderate alcohol intoxication on the spatiotemporal neural dynamics of event-related total theta (4 to 7 Hz) power as a function of task difficulty. Two variants of the Simon task manipulated incongruity via simple spatial stimulus-response mismatch and, in a more difficult version, by combining spatial and semantic interference. Healthy social drinkers participated in both alcohol (0.6 g/kg ethanol for men, 0.55 g/kg for women) and placebo conditions in a counterbalanced design. Whole-head magnetoencephalography (MEG) signals were acquired and event-related total theta power was calculated on each trial with Morlet wavelets. MEG sources were estimated using anatomically constrained, noise-normalized, spectral dynamic statistical parametric mapping. Longer reaction times and lower accuracy confirmed the difficulty manipulation. Response conflict (incongruity) increased and alcohol intoxication decreased event-related theta power overall during both tasks bilaterally in the medial and ventrolateral prefrontal cortices. However, alcohol-induced theta suppression was selective for conflict only in the more difficult task which engaged the dorsal anterior cingulate (dAC) and anterior inferolateral prefrontal cortices. Theta power correlated negatively with drinking levels and disinhibition, suggesting that cognitive control is susceptible in more impulsive individuals with higher alcohol intake. The spatiotemporal theta profile across the 2 tasks supports the concept of a rostrocaudal activity gradient in the medial prefrontal cortex that is modulated by task difficulty, with the dAC as the key node in the network subserving cognitive control. Conflict-related theta power was

  10. Imploding to equilibrium of helically symmetric theta pinches

    International Nuclear Information System (INIS)

    Sharky, N.N.

    1978-01-01

    The time-dependent, single-fluid, dissipative magnetohydrodynamic equations are solved in helical coordinates (r,phi), where phi = THETA-kz, k = 2π/L and L is the periodicity length in the z-direction. The two-dimensional numerical calculations simulate theta pinches which have an l = 1 helical field added to them. Given the applied magnetic fields and the initial state of the plasma, we study the time evolution of the system. The plasma is found to experience two kinds of oscillations, occurring on different time scales. These are the radial compression oscillations, and the slower helical oscillations of the plasma column. The plasma motion is followed until these oscillations disappear and an equilibrium is nearly reached. Hence given the amplitude and the rise time of the applied magnetic fields, the calculations allow one to relate the initial state of a cold, homogeneous plasma to its final equilibrium state where it is heated and compressed

  11. Opacity test using a neon-seeded theta pinch

    International Nuclear Information System (INIS)

    Thomson, D.B.

    1980-02-01

    Vacuum ultraviolet (VUV) emission from a neon-seeded high-density theta-pinch has been observed for comparison with theoretical radiation emission calculations. The plasma was created in a 25-cm-long theta-coil with 90-kG field having a 3.0-μs quarter period. A gas fill of 1 torr of helium + 2% neon was used. Observation of the HeII 4686 line/continuum ratio gave an electron temperature of 25 +- 4 eV. Shadowgraphs of the plasma radius, taken with a ruby laser, gave an electron density of 0.9 +- 0.09 x 10 18 cm -3 . The VUV emission was observed in radial view and with time resolution with a 2.2-m grazing-incidence monochromator equipped with a photomultiplier and p-terphenyl scintillator. Thin foils of carbon and aluminum were used as filters to absorb stray light and pass emission in the 44- to 100-A region

  12. The True Ultracool Binary Fraction Using Spectral Binaries

    Science.gov (United States)

    Bardalez Gagliuffi, Daniella; Burgasser, Adam J.; Schmidt, Sarah J.; Gagné, Jonathan; Faherty, Jacqueline K.; Cruz, Kelle; Gelino, Chris

    2018-01-01

    Brown dwarfs bridge the gap between stars and giant planets. While the essential mechanisms governing their formation are not well constrained, binary statistics are a direct outcome of the formation process, and thus provide a means to test formation theories. Observational constraints on the brown dwarf binary fraction place it at 10 ‑ 20%, dominated by imaging studies (85% of systems) with the most common separation at 4 AU. This coincides with the resolution limit of state-of-the-art imaging techniques, suggesting that the binary fraction is underestimated. We have developed a separation-independent method to identify and characterize tightly-separated (dwarfs as spectral binaries by identifying traces of methane in the spectra of late-M and early-L dwarfs. Imaging follow-up of 17 spectral binaries yielded 3 (18%) resolved systems, corroborating the observed binary fraction, but 5 (29%) known binaries were missed, reinforcing the hypothesis that the short-separation systems are undercounted. In order to find the true binary fraction of brown dwarfs, we have compiled a volume-limited, spectroscopic sample of M7-L5 dwarfs and searched for T dwarf companions. In the 25 pc volume, 4 candidates were found, three of which are already confirmed, leading to a spectral binary fraction of 0.95 ± 0.50%, albeit for a specific combination of spectral types. To extract the true binary fraction and determine the biases of the spectral binary method, we have produced a binary population simulation based on different assumptions of the mass function, age distribution, evolutionary models and mass ratio distribution. Applying the correction fraction resulting from this method to the observed spectral binary fraction yields a true binary fraction of 27 ± 4%, which is roughly within 1σ of the binary fraction obtained from high resolution imaging studies, radial velocity and astrometric monitoring. This method can be extended to identify giant planet companions to young brown

  13. Selective Entrainment of Theta Oscillations in the Dorsal Stream Causally Enhances Auditory Working Memory Performance.

    Science.gov (United States)

    Albouy, Philippe; Weiss, Aurélien; Baillet, Sylvain; Zatorre, Robert J

    2017-04-05

    The implication of the dorsal stream in manipulating auditory information in working memory has been recently established. However, the oscillatory dynamics within this network and its causal relationship with behavior remain undefined. Using simultaneous MEG/EEG, we show that theta oscillations in the dorsal stream predict participants' manipulation abilities during memory retention in a task requiring the comparison of two patterns differing in temporal order. We investigated the causal relationship between brain oscillations and behavior by applying theta-rhythmic TMS combined with EEG over the MEG-identified target (left intraparietal sulcus) during the silent interval between the two stimuli. Rhythmic TMS entrained theta oscillation and boosted participants' accuracy. TMS-induced oscillatory entrainment scaled with behavioral enhancement, and both gains varied with participants' baseline abilities. These effects were not seen for a melody-comparison control task and were not observed for arrhythmic TMS. These data establish theta activity in the dorsal stream as causally related to memory manipulation. VIDEO ABSTRACT. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Frontal theta and beta synchronizations for monetary reward increase visual working memory capacity.

    Science.gov (United States)

    Kawasaki, Masahiro; Yamaguchi, Yoko

    2013-06-01

    Visual working memory (VWM) capacity is affected by motivational influences; however, little is known about how reward-related brain activities facilitate the VWM systems. To investigate the dynamic relationship between VWM- and reward-related brain activities, we conducted time-frequency analyses using electroencephalograph (EEG) data obtained during a monetary-incentive delayed-response task that required participants to memorize the position of colored disks. In case of a correct answer, participants received a monetary reward (0, 10 or 50 Japanese yen) announced at the beginning of each trial. Behavioral results showed that VWM capacity under high-reward condition significantly increased compared with that under low- or no-reward condition. EEG results showed that frontal theta (6 Hz) amplitudes enhanced during delay periods and positively correlated with VWM capacity, indicating involvement of theta local synchronizations in VWM. Moreover, frontal beta activities (24 Hz) were identified as reward-related activities, because delay-period amplitudes correlated with increases in VWM capacity between high-reward and no-reward conditions. Interestingly, cross-frequency couplings between frontal theta and beta phases were observed only under high-reward conditions. These findings suggest that the functional dynamic linking between VWM-related theta and reward-related beta activities on the frontal regions plays an integral role in facilitating increases in VWM capacity.

  15. The analyzing power Asub(y)(theta) for the elastic scattering of 12 MeV neutrons from deuterons

    International Nuclear Information System (INIS)

    Tornow, W.; Lisowski, P.W.; Byrd, R.C.; Walter, R.L.

    1978-01-01

    The analyzing power Asub(y)(theta) was obtained at 10 0 intervals between 30 0 (lab) to 120 0 (lab) for 2 H(n, n) 2 H at 12.0 MeV. The polarized neutron beam employed in the measurement was obtained by using neutrons emitted at 0 0 from the polarization transfer reaction 2 H(d(pol), n(pol)) 3 He. The accuracy in the Asub(y)(theta) values that was achieved ranged from +- 0.006 to +- 0.013. Comparison of the data to Asub(y)(theta) results obtained at 12 MeV for the charge symmetric reaction 2 H(p, p) 2 H shows that the two Asub(y)(theta) distributions are equal to within the above accuracy. (Auth.)

  16. Crystallization, data collection and phasing of two digestive lysozymes from Musca domestica

    Energy Technology Data Exchange (ETDEWEB)

    Marana, S. R.; Cançado, F. C. [Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo (Brazil); Valério, A. A. [Centro de Biologia Molecular e Estrutural (CeBiMe), Laboratório Nacional de Luz Síncrotron (LNLS), CP 6192, Campinas, SP 13084-971 (Brazil); Departamento de Bioquímica, Universidade Estadual de Campinas, Campinas (Brazil); Ferreira, C.; Terra, W. R. [Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo (Brazil); Barbosa, J. A. R. G., E-mail: joao@lnls.br [Centro de Biologia Molecular e Estrutural (CeBiMe), Laboratório Nacional de Luz Síncrotron (LNLS), CP 6192, Campinas, SP 13084-971 (Brazil); Departamento de Bioquímica, Universidade Estadual de Campinas, Campinas (Brazil); Departamento de Genética e Evolução, Universidade Estadual de Campinas, Campinas (Brazil); Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo (Brazil)

    2006-08-01

    The digestive lysozymes 1 and 2 from M. domestica were crystallized by vapour diffusion. The crystallographic data were processed to a maximum resolution of 1.9 Å in both cases. Lysozymes are mostly known for their defensive role against bacteria, but in several animals lysozymes have a digestive function. Here, the initial crystallographic characterization of two digestive lysozymes from Musca domestica are presented. The proteins were crystallized using the sitting-drop vapour-diffusion method in the presence of ammonium sulfate or PEG/2-propanol as the precipitant. X-ray diffraction data were collected to a maximum resolution of 1.9 Å using synchrotron radiation. The lysozyme 1 and 2 crystals belong to the monoclinic space group P2{sub 1} (unit-cell parameters a = 36.52, b = 79.44, c = 45.20 Å, β = 102.97°) and the orthorhombic space group P2{sub 1}2{sub 1}2 (unit-cell parameters a = 73.90, b = 96.40, c = 33.27 Å), respectively. The crystal structures were solved by molecular replacement and structure refinement is in progress.

  17. Theta rhythm-like bidirectional cycling dynamics of living neuronal networks in vitro.

    Science.gov (United States)

    Gladkov, Arseniy; Grinchuk, Oleg; Pigareva, Yana; Mukhina, Irina; Kazantsev, Victor; Pimashkin, Alexey

    2018-01-01

    The phenomena of synchronization, rhythmogenesis and coherence observed in brain networks are believed to be a dynamic substrate for cognitive functions such as learning and memory. However, researchers are still debating whether the rhythmic activity emerges from the network morphology that developed during neurogenesis or as a result of neuronal dynamics achieved under certain conditions. In the present study, we observed self-organized spiking activity that converged to long, complex and rhythmically repeated superbursts in neural networks formed by mature hippocampal cultures with a high cellular density. The superburst lasted for tens of seconds and consisted of hundreds of short (50-100 ms) small bursts with a high spiking rate of 139.0 ± 78.6 Hz that is associated with high-frequency oscillations in the hippocampus. In turn, the bursting frequency represents a theta rhythm (11.2 ± 1.5 Hz). The distribution of spikes within the bursts was non-random, representing a set of well-defined spatio-temporal base patterns or motifs. The long superburst was classified into two types. Each type was associated with a unique direction of spike propagation and, hence, was encoded by a binary sequence with random switching between the two "functional" states. The precisely structured bidirectional rhythmic activity that developed in self-organizing cultured networks was quite similar to the activity observed in the in vivo experiments.

  18. Theta rhythm-like bidirectional cycling dynamics of living neuronal networks in vitro.

    Directory of Open Access Journals (Sweden)

    Arseniy Gladkov

    Full Text Available The phenomena of synchronization, rhythmogenesis and coherence observed in brain networks are believed to be a dynamic substrate for cognitive functions such as learning and memory. However, researchers are still debating whether the rhythmic activity emerges from the network morphology that developed during neurogenesis or as a result of neuronal dynamics achieved under certain conditions. In the present study, we observed self-organized spiking activity that converged to long, complex and rhythmically repeated superbursts in neural networks formed by mature hippocampal cultures with a high cellular density. The superburst lasted for tens of seconds and consisted of hundreds of short (50-100 ms small bursts with a high spiking rate of 139.0 ± 78.6 Hz that is associated with high-frequency oscillations in the hippocampus. In turn, the bursting frequency represents a theta rhythm (11.2 ± 1.5 Hz. The distribution of spikes within the bursts was non-random, representing a set of well-defined spatio-temporal base patterns or motifs. The long superburst was classified into two types. Each type was associated with a unique direction of spike propagation and, hence, was encoded by a binary sequence with random switching between the two "functional" states. The precisely structured bidirectional rhythmic activity that developed in self-organizing cultured networks was quite similar to the activity observed in the in vivo experiments.

  19. Electrical insulators for the theta-pinch fusion reactor

    International Nuclear Information System (INIS)

    Clinard, F.W. Jr.

    1976-01-01

    The five major applications for electrical insulators in the Reference Theta Pinch Reactor are as follows: (1) first-wall insulator, (2) blanket intersegment insulator, (3) graphite encapsulating insulator, (4) implosion coil insulator, and (5) compression coil insulator. Insulator design proposals and some preliminary test results are given for each application

  20. Temporal correlation between auditory neurons and the hippocampal theta rhythm induced by novel stimulations in awake guinea pigs.

    Science.gov (United States)

    Liberman, Tamara; Velluti, Ricardo A; Pedemonte, Marisa

    2009-11-17

    The hippocampal theta rhythm is associated with the processing of sensory systems such as touch, smell, vision and hearing, as well as with motor activity, the modulation of autonomic processes such as cardiac rhythm, and learning and memory processes. The discovery of temporal correlation (phase locking) between the theta rhythm and both visual and auditory neuronal activity has led us to postulate the participation of such rhythm in the temporal processing of sensory information. In addition, changes in attention can modify both the theta rhythm and the auditory and visual sensory activity. The present report tested the hypothesis that the temporal correlation between auditory neuronal discharges in the inferior colliculus central nucleus (ICc) and the hippocampal theta rhythm could be enhanced by changes in sensory stimulation. We presented chronically implanted guinea pigs with auditory stimuli that varied over time, and recorded the auditory response during wakefulness. It was observed that the stimulation shifts were capable of producing the temporal phase correlations between the theta rhythm and the ICc unit firing, and they differed depending on the stimulus change performed. Such correlations disappeared approximately 6 s after the change presentation. Furthermore, the power of the hippocampal theta rhythm increased in half of the cases presented with a stimulation change. Based on these data, we propose that the degree of correlation between the unitary activity and the hippocampal theta rhythm varies with--and therefore may signal--stimulus novelty.

  1. Behavioural Inhibition System (BIS) sensitivity differentiates EEG theta responses during goal conflict in a continuous monitoring task.

    Science.gov (United States)

    Moore, Roger A; Mills, Matthew; Marshman, Paul; Corr, Philip J

    2012-08-01

    Previous research has revealed that EEG theta oscillations are affected during goal conflict processing. This is consistent with the behavioural inhibition system (BIS) theory of anxiety (Gray & McNaughton, 2000). However, studies have not attempted to relate these BIS-related theta effects to BIS personality measures. Confirmation of such an association would provide further support for BIS theory, especially as it relates to trait differences. EEG was measured (32 electrodes) from extreme groups (low/high trait BIS) engaged in a target detection task. Goal conflicts were introduced throughout the task. Results show that the two groups did not differ in behavioural performance. The major EEG result was that a stepwise discriminant analysis indicated discrimination by 6 variables derived from coherence and power, with 5 of the 6 in the theta range as predicted by BIS theory and one in the beta range. Also, across the whole sample, EEG theta coherence increased at a variety of regions during primary goal conflict and showed a general increase during response execution; EEG theta power, in contrast, was primarily reactive to response execution. This is the first study to reveal a three-way relationship between the induction of goal conflict, the induction of theta power and coherence, and differentiation by psychometrically-defined low/high BIS status. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Algebraic geometry and theta functions

    CERN Document Server

    Coble, Arthur B

    1929-01-01

    This book is the result of extending and deepening all questions from algebraic geometry that are connected to the central problem of this book: the determination of the tritangent planes of a space curve of order six and genus four, which the author treated in his Colloquium Lecture in 1928 at Amherst. The first two chapters recall fundamental ideas of algebraic geometry and theta functions in such fashion as will be most helpful in later applications. In order to clearly present the state of the central problem, the author first presents the better-known cases of genus two (Chapter III) and

  3. The morphology of midcingulate cortex predicts frontal-midline theta neurofeedback success

    Directory of Open Access Journals (Sweden)

    Stefanie eEnriquez-Geppert

    2013-08-01

    Full Text Available Humans differ in their ability to learn how to control their own brain activity by neurofeedback. However, neural mechanisms underlying these inter-individual differences, which may determine training success and associated cognitive enhancement, are not well understood. Here, it is asked whether neurofeedback success of frontal-midline (fm theta, an oscillation related to higher cognitive functions, could be predicted by the morphology of brain structures known to be critically involved in fm-theta generation. Nineteen young, right-handed participants underwent magnetic resonance imaging of T1-weighted brain images, and took part in an individualized, eight-session neurofeedback training in order to learn how to enhance activity in their fm-theta frequency band. Initial training success, measured at the second training session, was correlated with the final outcome measure. We found that the inferior, superior and middle frontal cortices were not associated with training success. However, volume of the midcingulate cortex as well as volume and concentration of the underlying white matter structures act as predictor variables for the general responsiveness to training. These findings suggest a neuroanatomical foundation for the ability to learn to control one’s own brain activity.

  4. Learning to assign binary weights to binary descriptor

    Science.gov (United States)

    Huang, Zhoudi; Wei, Zhenzhong; Zhang, Guangjun

    2016-10-01

    Constructing robust binary local feature descriptors are receiving increasing interest due to their binary nature, which can enable fast processing while requiring significantly less memory than their floating-point competitors. To bridge the performance gap between the binary and floating-point descriptors without increasing the computational cost of computing and matching, optimal binary weights are learning to assign to binary descriptor for considering each bit might contribute differently to the distinctiveness and robustness. Technically, a large-scale regularized optimization method is applied to learn float weights for each bit of the binary descriptor. Furthermore, binary approximation for the float weights is performed by utilizing an efficient alternatively greedy strategy, which can significantly improve the discriminative power while preserve fast matching advantage. Extensive experimental results on two challenging datasets (Brown dataset and Oxford dataset) demonstrate the effectiveness and efficiency of the proposed method.

  5. Ih tunes theta/gamma oscillations and cross-frequency coupling in an in silico CA3 model.

    Directory of Open Access Journals (Sweden)

    Samuel A Neymotin

    Full Text Available Ih channels are uniquely positioned to act as neuromodulatory control points for tuning hippocampal theta (4-12 Hz and gamma (25 Hz oscillations, oscillations which are thought to have importance for organization of information flow. contributes to neuronal membrane resonance and resting membrane potential, and is modulated by second messengers. We investigated oscillatory control using a multiscale computer model of hippocampal CA3, where each cell class (pyramidal, basket, and oriens-lacunosum moleculare cells, contained type-appropriate isoforms of . Our model demonstrated that modulation of pyramidal and basket allows tuning theta and gamma oscillation frequency and amplitude. Pyramidal also controlled cross-frequency coupling (CFC and allowed shifting gamma generation towards particular phases of the theta cycle, effected via 's ability to set pyramidal excitability. Our model predicts that in vivo neuromodulatory control of allows flexibly controlling CFC and the timing of gamma discharges at particular theta phases.

  6. Combinatorics of tenth-order mock theta functions

    Indian Academy of Sciences (India)

    θ(q) there is some root of unity ζ for which f (q) − θ(q) is unbounded as q → ζ rapidly. In the long list of 17 mock theta functions given by Ramanujan, few have been interpreted combinatorially. For example, (q) defined by (1.1) below, has been interpreted by Fine. [8] as a generating function for partitions into odd parts without ...

  7. Instantons, theta-vacua, confinement..... a pedagogical introduction

    International Nuclear Information System (INIS)

    Teper, M.J.

    1980-01-01

    In this series of lectures the concept of the instanton and its various ramifications, such as the dilute gas and theta-vacua, are introduced through the relatively simple dynamical system of 1 + 1 dimensional quantum mechanics and the 1 + 1 abelian Higgs model. Although QCD is not dealt with explicitly those aspects of the argument which are relevant to that much more complicated theory are noted. (UK)

  8. Upsilon NU: Our chapter in Sigma Theta Tau Internacional Upsilon NU: nuestro capítulo en Sigma Theta Tau International

    Directory of Open Access Journals (Sweden)

    GARZÓN ALARCÓN NELLY

    2008-07-01

    Full Text Available ALa Sociedad de Honor de Enfermería, Sigma Theta Tau Internacional, es una organización que nace y vive para desarrollar el conocimiento y la ciencia de enfermería como fundamentos del liderazgo y la búsqueda de la excelencia en el cuidado de la persona, la familia y la comunidad.

  9. Dynamic links between theta executive functions and alpha storage buffers in auditory and visual working memory.

    Science.gov (United States)

    Kawasaki, Masahiro; Kitajo, Keiichi; Yamaguchi, Yoko

    2010-05-01

    Working memory (WM) tasks require not only distinct functions such as a storage buffer and central executive functions, but also coordination among these functions. Neuroimaging studies have revealed the contributions of different brain regions to different functional roles in WM tasks; however, little is known about the neural mechanism governing their coordination. Electroencephalographic (EEG) rhythms, especially theta and alpha, are known to appear over distributed brain regions during WM tasks, but the rhythms associated with task-relevant regional coupling have not been obtained thus far. In this study, we conducted time-frequency analyses for EEG data in WM tasks that include manipulation periods and memory storage buffer periods. We used both auditory WM tasks and visual WM tasks. The results successfully demonstrated function-specific EEG activities. The frontal theta amplitudes increased during the manipulation periods of both tasks. The alpha amplitudes increased during not only the manipulation but also the maintenance periods in the temporal area for the auditory WM and the parietal area for the visual WM. The phase synchronization analyses indicated that, under the relevant task conditions, the temporal and parietal regions show enhanced phase synchronization in the theta bands with the frontal region, whereas phase synchronization between theta and alpha is significantly enhanced only within the individual areas. Our results suggest that WM task-relevant brain regions are coordinated by distant theta synchronization for central executive functions, by local alpha synchronization for the memory storage buffer, and by theta-alpha coupling for inter-functional integration.

  10. Creep curve modeling of hastelloy-X alloy by using the theta projection method

    International Nuclear Information System (INIS)

    Woo Gon, Kim; Woo-Seog, Ryu; Jong-Hwa, Chang; Song-Nan, Yin

    2007-01-01

    To model the creep curves of the Hastelloy-X alloy which is being considered as a candidate material for the VHTR (Very High Temperature gas-cooled Reactor) components, full creep curves were obtained by constant-load creep tests for different stress levels at 950 C degrees. Using the experimental creep data, the creep curves were modeled by applying the Theta projection method. A number of computing processes of a nonlinear least square fitting (NLSF) analysis was carried out to establish the suitably of the four Theta parameters. The results showed that the Θ 1 and Θ 2 parameters could not be optimized well with a large error during the fitting of the full creep curves. On the other hand, the Θ 3 and Θ 4 parameters were optimized well without an error. For this result, to find a suitable cutoff strain criterion, the NLSF analysis was performed with various cutoff strains for all the creep curves. An optimum cutoff strain range for defining the four Theta parameters accurately was found to be a 3% cutoff strain. At the 3% cutoff strain, the predicted curves coincided well with the experimental ones. The variation of the four Theta parameters as the function of a stress showed a good linearity, and the creep curves were modeled well for the low stress levels. Predicted minimum creep rate showed a good agreement with the experimental data. Also, for a design usage of the Hastelloy-X alloy, the plot of the log stress versus log the time to a 1% strain was predicted, and the creep rate curves with time and a cutoff strain at 950 C degrees were constructed numerically for a wide rang of stresses by using the Theta projection method. (authors)

  11. Why don't you like me? : Midfrontal theta power in response to unexpected peer rejection feedback

    NARCIS (Netherlands)

    van der Molen, M.J.W.; Dekkers, L.M.S.; Westenberg, P.M.; van der Veen, F.M.; van der Molen, M.W.

    2017-01-01

    Social connectedness theory posits that the brain processes social rejection as a threat to survival. Recent electrophysiological evidence suggests that midfrontal theta (4–8 Hz) oscillations in the EEG provide a window on the processing of social rejection. Here we examined midfrontal theta

  12. Study of CP(N-1) theta-vacua by cluster simulation of SU(N) quantum spin ladders.

    Science.gov (United States)

    Beard, B B; Pepe, M; Riederer, S; Wiese, U-J

    2005-01-14

    D-theory provides an alternative lattice regularization of the 2D CP(N-1) quantum field theory in which continuous classical fields emerge from the dimensional reduction of discrete SU(N) quantum spins. Spin ladders consisting of n transversely coupled spin chains lead to a CP(N-1) model with a vacuum angle theta=npi. In D-theory no sign problem arises and an efficient cluster algorithm is used to investigate theta-vacuum effects. At theta=pi there is a first order phase transition with spontaneous breaking of charge conjugation symmetry for CP(N-1) models with N>2.

  13. Index of alpha/theta ratio of the electroencephalogram: a new marker for Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Magali eSchmidt

    2013-10-01

    Full Text Available Objective: We evaluated quantitative EEG measures to determine a screening index to discriminate AD patients from normal individuals. Methods: Two groups of individuals older than 50 years, comprising a control group of 57 normal volunteers and a study group of 50 patients with probable AD, were compared. EEG recordings were obtained from subjects in a wake state with eyes closed at rest for 30 min. Logistic regression analysis was conducted. Results: Spectral potentials of the alpha and theta bands were computed for all electrodes and the alpha/theta ratio calculated. Logistic regression of alpha/theta of the mean potential of the C3 and O1 electrodes was carried out. A formula was calculated to aid the diagnosis of AD yielding 76.4 % sensitivity and 84.6 specificity for AD with an area under the ROC curve of 0.92. Conclusions: Logistic regression of alpha/theta of the spectrum of the mean potential of EEG represents a good marker discriminating AD patients from normal controls.

  14. Complementary theta resonance filtering by two spatially segregated mechanisms in CA1 hippocampal pyramidal neurons.

    Science.gov (United States)

    Hu, Hua; Vervaeke, Koen; Graham, Lyle J; Storm, Johan F

    2009-11-18

    Synaptic input to a neuron may undergo various filtering steps, both locally and during transmission to the soma. Using simultaneous whole-cell recordings from soma and apical dendrites from rat CA1 hippocampal pyramidal cells, and biophysically detailed modeling, we found two complementary resonance (bandpass) filters of subthreshold voltage signals. Both filters favor signals in the theta (3-12 Hz) frequency range, but have opposite location, direction, and voltage dependencies: (1) dendritic H-resonance, caused by h/HCN-channels, filters signals propagating from soma to dendrite when the membrane potential is close to rest; and (2) somatic M-resonance, caused by M/Kv7/KCNQ and persistent Na(+) (NaP) channels, filters signals propagating from dendrite to soma when the membrane potential approaches spike threshold. Hippocampal pyramidal cells participate in theta network oscillations during behavior, and we suggest that that these dual, polarized theta resonance mechanisms may convey voltage-dependent tuning of theta-mediated neural coding in the entorhinal/hippocampal system during locomotion, spatial navigation, memory, and sleep.

  15. The theta/gamma discrete phase code occuring during the hippocampal phase precession may be a more general brain coding scheme.

    Science.gov (United States)

    Lisman, John

    2005-01-01

    In the hippocampus, oscillations in the theta and gamma frequency range occur together and interact in several ways, indicating that they are part of a common functional system. It is argued that these oscillations form a coding scheme that is used in the hippocampus to organize the readout from long-term memory of the discrete sequence of upcoming places, as cued by current position. This readout of place cells has been analyzed in several ways. First, plots of the theta phase of spikes vs. position on a track show a systematic progression of phase as rats run through a place field. This is termed the phase precession. Second, two cells with nearby place fields have a systematic difference in phase, as indicated by a cross-correlation having a peak with a temporal offset that is a significant fraction of a theta cycle. Third, several different decoding algorithms demonstrate the information content of theta phase in predicting the animal's position. It appears that small phase differences corresponding to jitter within a gamma cycle do not carry information. This evidence, together with the finding that principle cells fire preferentially at a given gamma phase, supports the concept of theta/gamma coding: a given place is encoded by the spatial pattern of neurons that fire in a given gamma cycle (the exact timing within a gamma cycle being unimportant); sequential places are encoded in sequential gamma subcycles of the theta cycle (i.e., with different discrete theta phase). It appears that this general form of coding is not restricted to readout of information from long-term memory in the hippocampus because similar patterns of theta/gamma oscillations have been observed in multiple brain regions, including regions involved in working memory and sensory integration. It is suggested that dual oscillations serve a general function: the encoding of multiple units of information (items) in a way that preserves their serial order. The relationship of such coding to

  16. Frontal theta EEG dynamics in a real-world air traffic control task.

    Science.gov (United States)

    Shou, Guofa; Ding, Lei

    2013-01-01

    Mental workload and time-on-task effect are two major factors expediting fatigue progress, which leads to performance decline and/or failure in real-world tasks. In the present study, electroencephalography (EEG) is applied to study mental fatigue development during an air traffic control (ATC) task. Specifically, the frontal theta EEG dynamics are firstly dissolved into a unique frontal independent component (IC) through a novel time-frequency independent component analysis (tfICA) method. Then the temporal fluctuations of the identified frontal ICs every minute are compared to workload (reflected by number of clicks per minute) and time-on-task effect by correlational analysis and linear regression analysis. It is observed that the frontal theta activity significantly increase with workload augment and time-on-task. The present study demonstrates that the frontal theta EEG activity identified by tfICA method is a sensitive and reliable metric to assess mental workload and time-on-task effect in a real-world task, i.e., ATC task, at the resolution of minute(s).

  17. Binary Linear-Time Erasure Decoding for Non-Binary LDPC codes

    OpenAIRE

    Savin, Valentin

    2009-01-01

    In this paper, we first introduce the extended binary representation of non-binary codes, which corresponds to a covering graph of the bipartite graph associated with the non-binary code. Then we show that non-binary codewords correspond to binary codewords of the extended representation that further satisfy some simplex-constraint: that is, bits lying over the same symbol-node of the non-binary graph must form a codeword of a simplex code. Applied to the binary erasure channel, this descript...

  18. Isolation and sequence of cDNA encoding a cytochrome P-450 from an insecticide-resistant strain of the house fly, Musca domestica.

    OpenAIRE

    Feyereisen, R; Koener, J F; Farnsworth, D E; Nebert, D W

    1989-01-01

    A cDNA expression library from phenobarbital-treated house fly (Musca domestica) was screened with rabbit antisera directed against partially purified house fly cytochrome P-450. Two overlapping clones with insert lengths of 1.3 and 1.5 kilobases were isolated. The sequence of a 1629-base-pair (bp) cDNA was obtained, with an open reading frame (nucleotides 81-1610) encoding a P-450 protein of 509 residues (Mr = 58,738). The insect P-450 protein contains a hydrophobic NH2 terminus and a 22-res...

  19. Entorhinal-CA3 Dual-Input Control of Spike Timing in the Hippocampus by Theta-Gamma Coupling.

    Science.gov (United States)

    Fernández-Ruiz, Antonio; Oliva, Azahara; Nagy, Gergő A; Maurer, Andrew P; Berényi, Antal; Buzsáki, György

    2017-03-08

    Theta-gamma phase coupling and spike timing within theta oscillations are prominent features of the hippocampus and are often related to navigation and memory. However, the mechanisms that give rise to these relationships are not well understood. Using high spatial resolution electrophysiology, we investigated the influence of CA3 and entorhinal inputs on the timing of CA1 neurons. The theta-phase preference and excitatory strength of the afferent CA3 and entorhinal inputs effectively timed the principal neuron activity, as well as regulated distinct CA1 interneuron populations in multiple tasks and behavioral states. Feedback potentiation of distal dendritic inhibition by CA1 place cells attenuated the excitatory entorhinal input at place field entry, coupled with feedback depression of proximal dendritic and perisomatic inhibition, allowing the CA3 input to gain control toward the exit. Thus, upstream inputs interact with local mechanisms to determine theta-phase timing of hippocampal neurons to support memory and spatial navigation. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Exponential mean-square stability of two classes of theta Milstein methods for stochastic delay differential equations

    Science.gov (United States)

    Rouz, Omid Farkhondeh; Ahmadian, Davood; Milev, Mariyan

    2017-12-01

    This paper establishes exponential mean square stability of two classes of theta Milstein methods, namely split-step theta Milstein (SSTM) method and stochastic theta Milstein (STM) method, for stochastic differential delay equations (SDDEs). We consider the SDDEs problem under a coupled monotone condition on drift and diffusion coefficients, as well as a necessary linear growth condition on the last term of theta Milstein method. It is proved that the SSTM method with θ ∈ [0, ½] can recover the exponential mean square stability of the exact solution with some restrictive conditions on stepsize, but for θ ∈ (½, 1], we proved that the stability results hold for any stepsize. Then, based on the stability results of SSTM method, we examine the exponential mean square stability of the STM method and obtain the similar stability results to that of the SSTM method. In the numerical section the figures show thevalidity of our claims.

  1. Associative-memory representations emerge as shared spatial patterns of theta activity spanning the primate temporal cortex.

    Science.gov (United States)

    Nakahara, Kiyoshi; Adachi, Ken; Kawasaki, Keisuke; Matsuo, Takeshi; Sawahata, Hirohito; Majima, Kei; Takeda, Masaki; Sugiyama, Sayaka; Nakata, Ryota; Iijima, Atsuhiko; Tanigawa, Hisashi; Suzuki, Takafumi; Kamitani, Yukiyasu; Hasegawa, Isao

    2016-06-10

    Highly localized neuronal spikes in primate temporal cortex can encode associative memory; however, whether memory formation involves area-wide reorganization of ensemble activity, which often accompanies rhythmicity, or just local microcircuit-level plasticity, remains elusive. Using high-density electrocorticography, we capture local-field potentials spanning the monkey temporal lobes, and show that the visual pair-association (PA) memory is encoded in spatial patterns of theta activity in areas TE, 36, and, partially, in the parahippocampal cortex, but not in the entorhinal cortex. The theta patterns elicited by learned paired associates are distinct between pairs, but similar within pairs. This pattern similarity, emerging through novel PA learning, allows a machine-learning decoder trained on theta patterns elicited by a particular visual item to correctly predict the identity of those elicited by its paired associate. Our results suggest that the formation and sharing of widespread cortical theta patterns via learning-induced reorganization are involved in the mechanisms of associative memory representation.

  2. Cytochrome P450 monooxygenase-mediated neonicotinoid resistance in the house fly Musca domestica L

    DEFF Research Database (Denmark)

    Markussen, Mette D K; Kristensen, Michael

    2010-01-01

    Neonicotinoids play an essential role in the control of house flies Musca domestica. The development of neonicotinoid resistance was found in two field populations. 766b was 130- and 140-fold resistant to imidacloprid and 17- and 28-fold resistant to thiamethoxam in males and females, respectively....... 791a was 22- and 20-fold resistant to imidacloprid and 9- and 23-fold resistant to thiamethoxam in males and females, respectively. Imidacloprid selection of 791a increased imidacloprid resistance to 75- and 150-fold in males and females, respectively, whereas selection with thiamethoxam had minimum...... of the imidacloprid-selected strain after neonicotinoid exposure. CYP6D1 expression was increased after neonicotinoid exposure in resistant males. CYP6D3 expression was induced in both sexes upon neonicotinoid exposure but significantly higher in females....

  3. A reversed-field theta-pinch plasma machine

    International Nuclear Information System (INIS)

    Yasojima, Yoshiyuki; Ueda, Yoshihiro; Sasao, Hiroyuki; Ueno, Noboru; Tanaka, Toshihide

    1984-01-01

    Mitsubishi Electric has constructed a reversed-field theta-pinch machine at its Central Research Laboratory and initiated a series of plasma diagnostics and control studies for development of nuclear-fusion technology. Although the device has a linear configuration, a stable high-temperature, high-density toroidal plasma can be generated. The article describes the overall structure, vacuum system, power-supply system, and diagnostics and control system of the plasma machine. (author)

  4. Sustained frontal midline theta enhancements during effortful listening track working memory demands.

    Science.gov (United States)

    Wisniewski, Matthew G; Iyer, Nandini; Thompson, Eric R; Simpson, Brian D

    2017-11-27

    Recent studies demonstrate that frontal midline theta power (4-8 Hz) enhancements in the electroencephalogram (EEG) relate to effortful listening. It has been proposed that these enhancements reflect working memory demands. Here, the need to retain auditory information in working memory was manipulated in a 2-interval 2-alternative forced-choice delayed pitch discrimination task ("Which interval contained the higher pitch?"). On each trial, two square wave stimuli differing in pitch at an individual's ∼70.7% correct threshold were separated by a 3-second ISI. In a 'Roving' condition, the lowest pitch stimulus was randomly selected on each trial (uniform distribution from 840 to 1160 Hz). In a 'Fixed' condition, the lowest pitch was always 979 Hz. Critically, the 'Fixed' condition allowed one to know the correct response immediately following the first stimulus (e.g., if the first stimulus is 979 Hz, the second must be higher). In contrast, the 'Roving' condition required retention of the first tone for comparison to the second. Frontal midline theta enhancements during the ISI were only observed for the 'Roving' condition. Alpha (8-13 Hz) enhancements were apparent during the ISI, but did not differ significantly between conditions. Since conditions were matched for accuracy at threshold, results suggest that frontal midline theta enhancements will not always accompany difficult listening. Mixed results in the literature regarding frontal midline theta enhancements may be related to differences between tasks in regards to working memory demands. Alpha enhancements may reflect task general effortful listening processes. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Alpha and theta brain oscillations index dissociable processes in spoken word recognition.

    Science.gov (United States)

    Strauß, Antje; Kotz, Sonja A; Scharinger, Mathias; Obleser, Jonas

    2014-08-15

    Slow neural oscillations (~1-15 Hz) are thought to orchestrate the neural processes of spoken language comprehension. However, functional subdivisions within this broad range of frequencies are disputed, with most studies hypothesizing only about single frequency bands. The present study utilizes an established paradigm of spoken word recognition (lexical decision) to test the hypothesis that within the slow neural oscillatory frequency range, distinct functional signatures and cortical networks can be identified at least for theta- (~3-7 Hz) and alpha-frequencies (~8-12 Hz). Listeners performed an auditory lexical decision task on a set of items that formed a word-pseudoword continuum: ranging from (1) real words over (2) ambiguous pseudowords (deviating from real words only in one vowel; comparable to natural mispronunciations in speech) to (3) pseudowords (clearly deviating from real words by randomized syllables). By means of time-frequency analysis and spatial filtering, we observed a dissociation into distinct but simultaneous patterns of alpha power suppression and theta power enhancement. Alpha exhibited a parametric suppression as items increasingly matched real words, in line with lowered functional inhibition in a left-dominant lexical processing network for more word-like input. Simultaneously, theta power in a bilateral fronto-temporal network was selectively enhanced for ambiguous pseudowords only. Thus, enhanced alpha power can neurally 'gate' lexical integration, while enhanced theta power might index functionally more specific ambiguity-resolution processes. To this end, a joint analysis of both frequency bands provides neural evidence for parallel processes in achieving spoken word recognition. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Binary effectivity rules

    DEFF Research Database (Denmark)

    Keiding, Hans; Peleg, Bezalel

    2006-01-01

    is binary if it is rationalized by an acyclic binary relation. The foregoing result motivates our definition of a binary effectivity rule as the effectivity rule of some binary SCR. A binary SCR is regular if it satisfies unanimity, monotonicity, and independence of infeasible alternatives. A binary...

  7. Reproduction and longevity of Supputius cincticeps (Het.: Pentatomidae) fed with larvae of Zophobas confusa, Tenebrio molitor (Col.: Tenebrionidae) or Musca domestica (Dip.: Muscidae)

    OpenAIRE

    Zanuncio,José Cola; Beserra,Eduardo Barbosa; Molina-Rugama,Adrián José; Zanuncio,Teresinha Vinha; Pinon,Tobias Baruc Moreira; Maffia,Vanessa Pataro

    2005-01-01

    Reproduction and longevity of Supputius cincticeps (Stål) (Heteroptera: Pentatomidae) fed on Zophobas confusa Gebien, Tenebrio molitor L. (Coleoptera: Tenebrionidae) or Musca domestica (L.) (Diptera: Muscidae) larvae were studied during two generations at 24.7 ± 1.1ºC, 70 ± 10% R.H. and 12 h of photophase. Body weight of newly-emerged adults, oviposition period, number of egg masses, total number of eggs and longevity of S. cincticeps were higher when fed on Z. confusa or T. mol...

  8. Theta frequency background tunes transmission but not summation of spiking responses.

    Directory of Open Access Journals (Sweden)

    Dhanya Parameshwaran

    Full Text Available Hippocampal neurons are known to fire as a function of frequency and phase of spontaneous network rhythms, associated with the animal's behaviour. This dependence is believed to give rise to precise rate and temporal codes. However, it is not well understood how these periodic membrane potential fluctuations affect the integration of synaptic inputs. Here we used sinusoidal current injection to the soma of CA1 pyramidal neurons in the rat brain slice to simulate background oscillations in the physiologically relevant theta and gamma frequency range. We used a detailed compartmental model to show that somatic current injection gave comparable results to more physiological synaptically driven theta rhythms incorporating excitatory input in the dendrites, and inhibitory input near the soma. We systematically varied the phase of synaptic inputs with respect to this background, and recorded changes in response and summation properties of CA1 neurons using whole-cell patch recordings. The response of the cell was dependent on both the phase of synaptic inputs and frequency of the background input. The probability of the cell spiking for a given synaptic input was up to 40% greater during the depolarized phases between 30-135 degrees of theta frequency current injection. Summation gain on the other hand, was not affected either by the background frequency or the phasic afferent inputs. This flat summation gain, coupled with the enhanced spiking probability during depolarized phases of the theta cycle, resulted in enhanced transmission of summed inputs during the same phase window of 30-135 degrees. Overall, our study suggests that although oscillations provide windows of opportunity to selectively boost transmission and EPSP size, summation of synaptic inputs remains unaffected during membrane oscillations.

  9. Search efficiency of Spalangia cameroni and Muscidifurax raptor on Musca domestica pupae in dairy cattle farms in Denmark

    DEFF Research Database (Denmark)

    Skovgård, Henrik

    2006-01-01

    significantly to overall parasitism, M. raptor had a significantly higher attack rate when first a female had located bags with sentinel pupae. Based on the above results, however, S. cameroni seems the most appropriate species for managing house flies in straw bedded dairy cattle farms in Denmark. A biological......Indoor releases of Spalangia cameroni Perkins and Muscidifurax raptor Girauelt & Sanders (Hymenoptera: Pteromalidae) were conducted in five organic dairy cattle farms to evaluate the overall effect on parasitism and efficiency at different pupal depths of Musca domestica L. (Diptera: Muscidae...... control strategy of simultaneous releases of S. cameroni and M. raptor is discussed. Key words: biological control, dairy cattle, dispersion, parasitism, Phygadeuon fumat...

  10. Frontal theta accounts for individual differences in the cost of conflict on decision making.

    Science.gov (United States)

    Pinner, John F L; Cavanagh, James F

    2017-10-01

    Cognitive conflict is often experienced as a difficult, frustrating, and aversive state. Recent studies have indicated that conflict acts as an implicit cost during learning, valuation, and the instantiation of cognitive control. Here we investigated if an implicit manipulation of conflict also influences explicit decision making to risk. Participants were required to perform a Balloon Analogue Risk Task wherein the virtual balloon was inflated by performing a flankers task. By varying the percent of incongruent flanker trials between balloons, we hypothesized that participants would pump the balloon fewer times in conditions of higher conflict and that frontal midline theta would account for significant variance in this relationship. Across two studies, we demonstrate that conflict did not elicit reliable behavioral changes in this task across participants. However, individual differences in frontal theta power accounted for significant variance by predicting diminished balloon pumps. Thus, while conflict costs may act as investments to some individuals (invigorating behavior), it is aversive to others (diminishing behavior), and frontal midline theta power accounts for these varying behavioral tendencies between individuals. These findings demonstrate how frontal midline theta is not only a candidate mechanism for implementing cognitive control, but it is sensitive to the inherent costs therein. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Intrahemispheric theta rhythm desynchronization impairs working memory.

    Science.gov (United States)

    Alekseichuk, Ivan; Pabel, Stefanie Corinna; Antal, Andrea; Paulus, Walter

    2017-01-01

    There is a growing interest in large-scale connectivity as one of the crucial factors in working memory. Correlative evidence has revealed the anatomical and electrophysiological players in the working memory network, but understanding of the effective role of their connectivity remains elusive. In this double-blind, placebo-controlled study we aimed to identify the causal role of theta phase connectivity in visual-spatial working memory. The frontoparietal network was over- or de-synchronized in the anterior-posterior direction by multi-electrode, 6 Hz transcranial alternating current stimulation (tACS). A decrease in memory performance and increase in reaction time was caused by frontoparietal intrahemispheric desynchronization. According to the diffusion drift model, this originated in a lower signal-to-noise ratio, known as the drift rate index, in the memory system. The EEG analysis revealed a corresponding decrease in phase connectivity between prefrontal and parietal areas after tACS-driven desynchronization. The over-synchronization did not result in any changes in either the behavioral or electrophysiological levels in healthy participants. Taken together, we demonstrate the feasibility of manipulating multi-site large-scale networks in humans, and the disruptive effect of frontoparietal desynchronization on theta phase connectivity and visual-spatial working memory.

  12. Differential distribution of glutamate- and GABA-gated chloride channels in the housefly Musca domestica.

    Science.gov (United States)

    Kita, Tomo; Ozoe, Fumiyo; Azuma, Masaaki; Ozoe, Yoshihisa

    2013-09-01

    l-Glutamic acid (glutamate) mediates fast inhibitory neurotransmission by affecting glutamate-gated chloride channels (GluCls) in invertebrates. The molecular function and pharmacological properties of GluCls have been well studied, but not much is known about their physiological role and localization in the insect body. The distribution of GluCls in the housefly (Musca domestica L.) was thus compared with the distribution of γ-aminobutyric acid (GABA)-gated chloride channels (GABACls). Quantitative PCR and ligand-binding experiments indicate that the GluCl and GABACl transcripts and proteins are predominantly expressed in the adult head. Intense GluCl immunostaining was detected in the lamina, leg motor neurons, and legs of adult houseflies. The GABACl (Rdl) immunostaining was more widely distributed, and was found in the medulla, lobula, lobula plate, mushroom body, antennal lobe, and ellipsoid body. The present findings suggest that GluCls have physiological roles in different tissues than GABACls. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. The electric dipole moment of the nucleon from simulations at imaginary vacuum angle theta

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, S. [RIKEN-BNL Research Center, Brookhaven National Laboratory, Upton (United States)]|[Tsukuba Univ. (Japan). Graduate School of Pure and Applied Sciences; Horsley, R.; Zanotti, J. [Edinburgh Univ. (United Kingdom). School of Physics; Izubuchi, T. [RIKEN-BNL Research Center, Brookhaven National Laboratory, Upton (United States)]|[Kanazawa Univ. (Japan). Inst. for Theoretical Physics; Nakamura, Y.; Pleiter, D.; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Division. Dept. of Mathematical Sciences

    2008-07-15

    We compute the electric dipole moment of proton and neutron from lattice QCD simulations with N{sub f}=2 flavors of dynamical quarks at imaginary vacuum angle {theta}. The calculation proceeds via the CP odd form factor F{sub 3}. A novel feature of our calculation is that we use partially twisted boundary conditions to extract F{sub 3} at zero momentum transfer. As a byproduct, we test the QCD vacuum at nonvanishing {theta}. (orig.)

  14. Eta Products and Theta Series Identities

    CERN Document Server

    Kohler, Gunter

    2011-01-01

    This monograph deals with products of Dedekind's eta function, with Hecke theta series on quadratic number fields, and with "Eisenstein series." The author brings to the public the large number of identities that have been discovered over the past 20 years, the majority of which have not been published elsewhere. This book will be of interest to graduate students and scholars in the field of number theory and, in particular, modular forms. It is not an introductory text in this field. Nevertheless, some theoretical background material is presented that is important for understanding

  15. Theta and Alpha Oscillations in Attentional Interaction during Distracted Driving

    Directory of Open Access Journals (Sweden)

    Yu-Kai Wang

    2018-02-01

    Full Text Available Performing multiple tasks simultaneously usually affects the behavioral performance as compared with executing the single task. Moreover, processing multiple tasks simultaneously often involve more cognitive demands. Two visual tasks, lane-keeping task and mental calculation, were utilized to assess the brain dynamics through 32-channel electroencephalogram (EEG recorded from 14 participants. A 400-ms stimulus onset asynchrony (SOA factor was used to induce distinct levels of attentional requirements. In the dual-task conditions, the deteriorated behavior reflected the divided attention and the overlapping brain resources used. The frontal, parietal and occipital components were decomposed by independent component analysis (ICA algorithm. The event- and response-related theta and alpha oscillations in selected brain regions were investigated first. The increased theta oscillation in frontal component and decreased alpha oscillations in parietal and occipital components reflect the cognitive demands and attentional requirements as executing the designed tasks. Furthermore, time-varying interactive over-additive (O-Add, additive (Add and under-additive (U-Add activations were explored and summarized through the comparison between the summation of the elicited spectral perturbations in two single-task conditions and the spectral perturbations in the dual task. Add and U-Add activations were observed while executing the dual tasks. U-Add theta and alpha activations dominated the posterior region in dual-task situations. Our results show that both deteriorated behaviors and interactive brain activations should be comprehensively considered for evaluating workload or attentional interaction precisely.

  16. Oscillatory theta activity during memory formation and its impact on overnight consolidation: a missing link?

    Science.gov (United States)

    Heib, Dominik P J; Hoedlmoser, Kerstin; Anderer, Peter; Gruber, Georg; Zeitlhofer, Josef; Schabus, Manuel

    2015-08-01

    Sleep has been shown to promote memory consolidation driven by certain oscillatory patterns, such as sleep spindles. However, sleep does not consolidate all newly encoded information uniformly but rather "selects" certain memories for consolidation. It is assumed that such selection depends on salience tags attached to the new memories before sleep. However, little is known about the underlying neuronal processes reflecting presleep memory tagging. The current study sought to address the question of whether event-related changes in spectral theta power (theta ERSP) during presleep memory formation could reflect memory tagging that influences subsequent consolidation during sleep. Twenty-four participants memorized 160 word pairs before sleep; in a separate laboratory visit, they performed a nonlearning control task. Memory performance was tested twice, directly before and after 8 hr of sleep. Results indicate that participants who improved their memory performance overnight displayed stronger theta ERSP during the memory task in comparison with the control task. They also displayed stronger memory task-related increases in fast sleep spindle activity. Furthermore, presleep theta activity was directly linked to fast sleep spindle activity, indicating that processes during memory formation might indeed reflect memory tagging that influences subsequent consolidation during sleep. Interestingly, our results further indicate that the suggested relation between sleep spindles and overnight performance change is not as direct as once believed. Rather, it appears to be mediated by processes beginning during presleep memory formation. We conclude that theta ERSP during presleep memory formation reflects cortico-hippocampal interactions that lead to a better long-term accessibility by tagging memories for sleep spindle-related reprocessing.

  17. Theta synchronization between medial prefrontal cortex and cerebellum is associated with adaptive performance of associative learning behavior

    Science.gov (United States)

    Chen, Hao; Wang, Yi-jie; Yang, Li; Sui, Jian-feng; Hu, Zhi-an; Hu, Bo

    2016-01-01

    Associative learning is thought to require coordinated activities among distributed brain regions. For example, to direct behavior appropriately, the medial prefrontal cortex (mPFC) must encode and maintain sensory information and then interact with the cerebellum during trace eyeblink conditioning (TEBC), a commonly-used associative learning model. However, the mechanisms by which these two distant areas interact remain elusive. By simultaneously recording local field potential (LFP) signals from the mPFC and the cerebellum in guinea pigs undergoing TEBC, we found that theta-frequency (5.0–12.0 Hz) oscillations in the mPFC and the cerebellum became strongly synchronized following presentation of auditory conditioned stimulus. Intriguingly, the conditioned eyeblink response (CR) with adaptive timing occurred preferentially in the trials where mPFC-cerebellum theta coherence was stronger. Moreover, both the mPFC-cerebellum theta coherence and the adaptive CR performance were impaired after the disruption of endogenous orexins in the cerebellum. Finally, association of the mPFC -cerebellum theta coherence with adaptive CR performance was time-limited occurring in the early stage of associative learning. These findings suggest that the mPFC and the cerebellum may act together to contribute to the adaptive performance of associative learning behavior by means of theta synchronization. PMID:26879632

  18. Theta oscillations are sensitive to both early and late conflict processing stages: effects of alcohol intoxication.

    Science.gov (United States)

    Kovacevic, Sanja; Azma, Sheeva; Irimia, Andrei; Sherfey, Jason; Halgren, Eric; Marinkovic, Ksenija

    2012-01-01

    Prior neuroimaging evidence indicates that decision conflict activates medial and lateral prefrontal and parietal cortices. Theoretical accounts of cognitive control highlight anterior cingulate cortex (ACC) as a central node in this network. However, a better understanding of the relative primacy and functional contributions of these areas to decision conflict requires insight into the neural dynamics of successive processing stages including conflict detection, response selection and execution. Moderate alcohol intoxication impairs cognitive control as it interferes with the ability to inhibit dominant, prepotent responses when they are no longer correct. To examine the effects of moderate intoxication on successive processing stages during cognitive control, spatio-temporal changes in total event-related theta power were measured during Stroop-induced conflict. Healthy social drinkers served as their own controls by participating in both alcohol (0.6 g/kg ethanol for men, 0.55 g/kg women) and placebo conditions in a counterbalanced design. Anatomically-constrained magnetoencephalography (aMEG) approach was applied to complex power spectra for theta (4-7 Hz) frequencies. The principal generator of event-related theta power to conflict was estimated to ACC, with contributions from fronto-parietal areas. The ACC was uniquely sensitive to conflict during both early conflict detection, and later response selection and execution stages. Alcohol attenuated theta power to conflict across successive processing stages, suggesting that alcohol-induced deficits in cognitive control may result from theta suppression in the executive network. Slower RTs were associated with attenuated theta power estimated to ACC, indicating that alcohol impairs motor preparation and execution subserved by the ACC. In addition to their relevance for the currently prevailing accounts of cognitive control, our results suggest that alcohol-induced impairment of top-down strategic processing

  19. Larvicidal potential of essential oils against Musca domestica and Anopheles stephensi.

    Science.gov (United States)

    Chauhan, Nitin; Malik, Anushree; Sharma, Satyawati; Dhiman, R C

    2016-06-01

    The larvicidal activity of Mentha piperita, Cymbopogan citratus (lemongrass), Eucalyptus globulus and Citrus sinensis (orange) essential oils and their combinations was evaluated against Musca domestica (housefly) and Anopheles stephensi (mosquitoes) through contact toxicity assay. Among all the tested essential oils/combinations, Me. piperita was found to be the most effective larvicidal agent against Mu. domestica and An. stephensi with LC50 values of 0.66 μl/cm(2) and 44.66 ppm, respectively, after 48 h. The results clearly highlighted that the addition of mentha oil to other oils (1:1 ratio) improved their larvicidal activity. The order of effectiveness of essential oils/combinations indicated that the pattern for An. stephensi follows the trend as mentha > mentha + lemongrass > lemongrass > mentha + eucalyptus > eucalyptus > mentha + orange > orange and for Mu. domestica as mentha > mentha + lemongrass > lemongrass > mentha + orange > orange > mentha + eucalyptus > eucalyptus. The images obtained from scanning electron microscopy (SEM) analysis indicated the toxic effect of Me. piperita as the treated larvae were observed to be dehydrated and deformed. This study demonstrates the effectiveness of tested essential oils/combinations against the larval stages of Mu. domestica and An. stephensi and has the potential for development of botanical formulations.

  20. A Comparison of Frontal Theta Activity During Shooting among Biathletes and Cross-Country Skiers before and after Vigorous Exercise.

    Directory of Open Access Journals (Sweden)

    Harri Luchsinger

    Full Text Available Previous studies using electroencephalography (EEG to monitor brain activity have linked higher frontal theta activity to more focused attention and superior performance in goal-directed precision tasks. In biathlon, shooting performance requires focused attention after high-intensity cross-country skiing.To compare biathletes (serving as experts and cross-country skiers (novices and examine the effect of vigorous exercise on frontal theta activity during shooting.EEG frontal theta (4-7 Hz activity was compared between nine biathletes and eight cross-country skiers at comparable skiing performance levels who fired 100 shots on a 5-m indoor shooting range in quiescent condition followed by 20 shots after each of five 6-min high-intensity roller skiing sessions in the skating technique on a treadmill.Biathletes hit 80±14% and 81±10% before and after the roller skiing sessions, respectively. For the cross-country skiers these values were significantly lower than for the biathletes and amounted to 39±13% and 44±11% (p<0.01. Biathletes had on average 6% higher frontal theta activity during shooting as compared to cross-country skiers (F1,15 = 4.82, p = 0.044, but no significant effect of vigorous exercise on frontal theta activity in either of the two groups were found (F1,15 = 0.14, p = 0.72.Biathletes had significantly higher frontal theta activity than cross-country skiers during shooting, indicating higher focused attention in biathletes. Vigorous exercise did not decrease shooting performance or frontal theta activity during shooting in biathletes and cross-country skiers.

  1. Change in hippocampal theta oscillation associated with multiple lever presses in a bimanual two-lever choice task for robot control in rats.

    Directory of Open Access Journals (Sweden)

    Norifumi Tanaka

    Full Text Available Hippocampal theta oscillations have been implicated in working memory and attentional process, which might be useful for the brain-machine interface (BMI. To further elucidate the properties of the hippocampal theta oscillations that can be used in BMI, we investigated hippocampal theta oscillations during a two-lever choice task. During the task body-restrained rats were trained with a food reward to move an e-puck robot towards them by pressing the correct lever, ipsilateral to the robot several times, using the ipsilateral forelimb. The robot carried food and moved along a semicircle track set in front of the rat. We demonstrated that the power of hippocampal theta oscillations gradually increased during a 6-s preparatory period before the start of multiple lever pressing, irrespective of whether the correct lever choice or forelimb side were used. In addition, there was a significant difference in the theta power after the first choice, between correct and incorrect trials. During the correct trials the theta power was highest during the first lever-releasing period, whereas in the incorrect trials it occurred during the second correct lever-pressing period. We also analyzed the hippocampal theta oscillations at the termination of multiple lever pressing during the correct trials. Irrespective of whether the correct forelimb side was used, the power of hippocampal theta oscillations gradually decreased with the termination of multiple lever pressing. The frequency of theta oscillation also demonstrated an increase and decrease, before and after multiple lever pressing, respectively. There was a transient increase in frequency after the first lever press during the incorrect trials, while no such increase was observed during the correct trials. These results suggested that hippocampal theta oscillations reflect some aspects of preparatory and cognitive neural activities during the robot controlling task, which could be used for BMI.

  2. Simple UHV offset manipulator with independent theta and phi rotations

    International Nuclear Information System (INIS)

    Jamison, K.D.; Dunning, F.B.

    1984-01-01

    A simple UHV offset manipulator is described that not only allows a target crystal to be moved to any point on a circle centered on the manipulator axis but also provides indepedent theta and phi rotations at each position

  3. YSOVAR: SIX PRE-MAIN-SEQUENCE ECLIPSING BINARIES IN THE ORION NEBULA CLUSTER

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Calderon, M.; Stauffer, J. R.; Rebull, L. M. [Spitzer Science Center, California Institute of Technology, 1200 E California Blvd., Pasadena, CA 91125 (United States); Stassun, K. G. [Physics and Astronomy Department, Vanderbilt University, 1807 Station B, Nashville, TN 37235 (United States); Vrba, F. J. [U. S. Naval Observatory, Flagstaff Station, 10391 W. Naval Observatory Road, Flagstaff, AZ 86001-8521 (United States); Prato, L. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Hillenbrand, L. A.; Carpenter, J. M. [Astronomy Department, California Institute of Technology, 1200 E California Blvd., Pasadena, CA 91125 (United States); Terebey, S.; Angione, J. [Department of Physics and Astronomy, California State University at Los Angeles, Los Angeles, CA 90032 (United States); Covey, K. R. [Department of Astronomy, Cornell University, 226 Space Sciences Building, Ithaca, NY 14853 (United States); Terndrup, D. M. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Gutermuth, R. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Song, I. [Physics and Astronomy Department, University of Georgia, Athens, GA 30602-2451 (United States); Plavchan, P. [NASA Exoplanet Science Institute, California Institute of Technology, Pasadena, CA 91125 (United States); Marchis, F. [SETI Institute, Carl Sagan Center, 189 N San Bernado Av, Mountain View, CA 94043 (United States); Garcia, E. V. [Department of Physics, Fisk University, 1000 17th Ave. N, Nashville, TN 37208 (United States); Margheim, S. [Gemini Observatory, Southern Operations Center, Casilla 603, La Serena (Chile); Luhman, K. L. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Irwin, J. M., E-mail: mariamc@cab.inta-csic.es [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)

    2012-07-10

    Eclipsing binaries (EBs) provide critical laboratories for empirically testing predictions of theoretical models of stellar structure and evolution. Pre-main-sequence (PMS) EBs are particularly valuable, both due to their rarity and the highly dynamic nature of PMS evolution, such that a dense grid of PMS EBs is required to properly calibrate theoretical PMS models. Analyzing multi-epoch, multi-color light curves for {approx}2400 candidate Orion Nebula Cluster (ONC) members from our Warm Spitzer Exploration Science Program YSOVAR, we have identified 12 stars whose light curves show eclipse features. Four of these 12 EBs are previously known. Supplementing our light curves with follow-up optical and near-infrared spectroscopy, we establish two of the candidates as likely field EBs lying behind the ONC. We confirm the remaining six candidate systems, however, as newly identified ONC PMS EBs. These systems increase the number of known PMS EBs by over 50% and include the highest mass ({theta}{sup 1} Ori E, for which we provide a complete set of well-determined parameters including component masses of 2.807 and 2.797 M{sub Sun }) and longest-period (ISOY J053505.71-052354.1, P {approx} 20 days) PMS EBs currently known. In two cases ({theta}{sup 1} Ori E and ISOY J053526.88-044730.7), enough photometric and spectroscopic data exist to attempt an orbit solution and derive the system parameters. For the remaining systems, we combine our data with literature information to provide a preliminary characterization sufficient to guide follow-up investigations of these rare, benchmark systems.

  4. Hippocampal theta activity is selectively associated with contingency detection but not discrimination in rabbit discrimination-reversal eyeblink conditioning.

    Science.gov (United States)

    Nokia, Miriam S; Wikgren, Jan

    2010-04-01

    The relative power of the hippocampal theta-band ( approximately 6 Hz) activity (theta ratio) is thought to reflect a distinct neural state and has been shown to affect learning rate in classical eyeblink conditioning in rabbits. We sought to determine if the theta ratio is mostly related to the detection of the contingency between the stimuli used in conditioning or also to the learning of more complex inhibitory associations when a highly demanding delay discrimination-reversal eyeblink conditioning paradigm is used. A high hippocampal theta ratio was not only associated with a fast increase in conditioned responding in general but also correlated with slow emergence of discriminative responding due to sustained responding to the conditioned stimulus not paired with an unconditioned stimulus. The results indicate that the neural state reflected by the hippocampal theta ratio is specifically linked to forming associations between stimuli rather than to the learning of inhibitory associations needed for successful discrimination. This is in line with the view that the hippocampus is responsible for contingency detection in the early phase of learning in eyeblink conditioning. (c) 2009 Wiley-Liss, Inc.

  5. Decreased rhythmic GABAergic septal activity and memory-associated theta oscillations after hippocampal amyloid-beta pathology in the rat.

    Science.gov (United States)

    Villette, Vincent; Poindessous-Jazat, Frédérique; Simon, Axelle; Léna, Clément; Roullot, Elodie; Bellessort, Brice; Epelbaum, Jacques; Dutar, Patrick; Stéphan, Aline

    2010-08-18

    The memory deficits associated with Alzheimer's disease result to a great extent from hippocampal network dysfunction. The coordination of this network relies on theta (symbol) oscillations generated in the medial septum. Here, we investigated in rats the impact of hippocampal amyloid beta (Abeta) injections on the physiological and cognitive functions that depend on the septohippocampal system. Hippocampal Abeta injections progressively impaired behavioral performances, the associated hippocampal theta power, and theta frequency response in a visuospatial recognition test. These alterations were associated with a specific reduction in the firing of the identified rhythmic bursting GABAergic neurons responsible for the propagation of the theta rhythm to the hippocampus, but without loss of medial septal neurons. Such results indicate that hippocampal Abeta treatment leads to a specific functional depression of inhibitory projection neurons of the medial septum, resulting in the functional impairment of the temporal network.

  6. Reproduction and longevity of Supputius cincticeps (Het.: Pentatomidae fed with larvae of Zophobas confusa, Tenebrio molitor (Col.: Tenebrionidae or Musca domestica (Dip.: Muscidae

    Directory of Open Access Journals (Sweden)

    José Cola Zanuncio

    2005-09-01

    Full Text Available Reproduction and longevity of Supputius cincticeps (Stål (Heteroptera: Pentatomidae fed on Zophobas confusa Gebien, Tenebrio molitor L. (Coleoptera: Tenebrionidae or Musca domestica (L. (Diptera: Muscidae larvae were studied during two generations at 24.7 ± 1.1ºC, 70 ± 10% R.H. and 12 h of photophase. Body weight of newly-emerged adults, oviposition period, number of egg masses, total number of eggs and longevity of S. cincticeps were higher when fed on Z. confusa or T. molitor larvae than on M. domestica larvae. Regardless of diet, S. cincticeps showed better reproduction and longevity in the second generation in laboratory conditions.Foram avaliadas, em duas gerações, a reprodução e a longevidade de Supputius cincticeps (Stål (Heteroptera: Pentatomidae alimentado com larvas de Zophobas confusa Gebien, Tenebrio molitor L. (Coleoptera: Tenebrionidae ou Musca domestica (L. (Diptera: Muscidae a 24,7 ± 1,1ºC, 70 ± 10% de U.R. e fotofase de 12 h. O peso de adultos recém emergidos, o período de oviposição, o número de posturas, de ovos totais e a longevidade de fêmeas de S. cincticeps foram maiores com larvas de Z. confusa ou T. molitor que com M. domestica. Independentemente do tipo de presa, S. cincticeps mostrou melhor performance reprodutiva e longevidade na segunda geração.

  7. House Fly (Musca domestica L. (Diptera Muscidae Development in Different Types of Manure Desarrollo de la Mosca Doméstica (Musca domestica L. (Díptera Muscidae en Distintos Tipos de Estiércol

    Directory of Open Access Journals (Sweden)

    Patricia Larraín S

    2008-06-01

    Full Text Available Animal production units with different management systems can be found along the Huasco Valley, Region of Atacama, Chile. These constitute sources of house flies (Musca domestica L. and other vector fly species that cause damage to animals and nuisance problems in urban areas. In order to asses the importance of fly breeding sources, an experiment was carried out under laboratory conditions to evaluate different types of animal manure and composted swine manure. Time of larval development, larva mortality, pupa size, and weight and time of development to the adult stage were assessed. Results show that swine, poultry and calf manure produced a significantly higher number of adult flies, shorter life cycles and larger and heavier pupae. Cow, dog, goat and horse manure follow in effectiviveness for fly production. Composted swine manure was totally ineffective for domestic fly development.En algunas comunas del Valle del Huasco, Región de Atacama, Chile, se encuentran diversas explotaciones pecuarias con diferentes sistemas de manejo, las cuales constituyen focos generadores de mosca doméstica, Musca domestica L., y otras especies de moscas con importancia sanitaria y médica. Estos insectos provocan pérdidas económicas en dichos planteles afectando además el bienestar de poblaciones urbanas cercanas. Con el objetivo de cuantificar la importancia de dichos focos en la generación de mosca doméstica, se realizó un ensayo de laboratorio donde se evaluó como sustrato de desarrollo del insecto estiércol de diferentes especies animales y estiércol de cerdo compostado. La calidad de estos sustratos en la producción del insecto se evaluó a través de los siguientes parámetros biológicos: tiempo de desarrollo de larvas, mortalidad de larvas, tamaño y peso de pupas, y tiempo hasta la emergencia de moscas adultas. Los resultados indicaron que el estiércol de cerdo, gallina y ternero produce significativamente más moscas adultas, con un

  8. Classical Conditioning of Hippocampal Theta Patterns in the Rat.

    Science.gov (United States)

    1976-08-01

    associated with changes in performance of learned tasks , 1,4,5, 8,9 there have been very few studies of neurona l plasticity of the hippocampus It self...rapid development of a conditioned hippocampal theta response to a visual sti mulus demonstrates tha t there is considerable neurona l plasticity in the

  9. Theta coupling between V4 and prefrontal cortex predicts visual short-term memory performance.

    Science.gov (United States)

    Liebe, Stefanie; Hoerzer, Gregor M; Logothetis, Nikos K; Rainer, Gregor

    2012-01-29

    Short-term memory requires communication between multiple brain regions that collectively mediate the encoding and maintenance of sensory information. It has been suggested that oscillatory synchronization underlies intercortical communication. Yet, whether and how distant cortical areas cooperate during visual memory remains elusive. We examined neural interactions between visual area V4 and the lateral prefrontal cortex using simultaneous local field potential (LFP) recordings and single-unit activity (SUA) in monkeys performing a visual short-term memory task. During the memory period, we observed enhanced between-area phase synchronization in theta frequencies (3-9 Hz) of LFPs together with elevated phase locking of SUA to theta oscillations across regions. In addition, we found that the strength of intercortical locking was predictive of the animals' behavioral performance. This suggests that theta-band synchronization coordinates action potential communication between V4 and prefrontal cortex that may contribute to the maintenance of visual short-term memories.

  10. White paper report on using nuclear reactors to search for a value of theta13

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, K.; Anjos, J.C.; Ayres, D.; Beacom, J.; Bediaga, I.; de Bellefon, A.; Berger, B.E.; Bilenky, S.; Blucher, E.; Bolton, T.; Buck, C.; Bugg, W.; Busenitz, J.; Choubey, S.; Conrad, J.; Cribier, M.; Dadoun, O.; Dalnoki-Veress, F.; Decowski, M.; de Gouvea, Andre; Demutrh, D.; Dessages-Ardellier, F.; Efremenko, Y.; von Feilitzsch, F.; Finley, D.; Formaggio, J.A.; Freedman, S.J.; Fujikawa, B.K.; Garbini, M.; Giusti, P.; Goger-Neff, M.; Goodman, M.; Gray, F.; Grieb, C.; Grudzinski, J.J.; Guarino, V.J.; Hartmann, F.; Hagner, C.; Heeger, K.M.; Hofmann, W.; Horton-Smith, G.; Huber, P.; Inzhechik, L.; Jochum, J.; Jostlein, H.; Kadel, R.; Kamyshkov, Y.; Kaplan, D.; Kasper, P.; de Kerret, H.; Kersten, J.; Klein, J.; Knopfle, K.T.; Kopeikin, V.; Kozlov, Yu.; Kryn, D.; Kuchler, V.; Kuze, M.; Lachenmaier, T.; Lasserre, T.; Laughton, C.; Lendvai, C.; Li, J.; Lindner, M.; Link, J.; Longo, M.; Lu, Y.S.; Luk, K.B.; Ma, Y.Q.; Martemyanov, V.P.; Mauger, C.; Manghetti, H.; McKeown, R.; Mention, G.; Meyer, J.P.; Mikaelyan, L.; Minakata, H.; Naples, D.; Nunokawa, H.; Oberauer, L.; Obolensky, M.; Parke, S.; Petcov, S.T.; Peres, O.L.G.; Potzel, W.; Pilcher, J.; Plunkett, R.; Raffelt, G.; Rapidis, P.; Reyna, D.; Roe, B.; Rolinec, M.; Sakamoto, Y.; Sartorelli, G.; Schonert, S.; Schwertz, T.; Selvi, M.; Shaevitz, M.; Shellard, R.; Shrock, R.; Sidwell, R.; Sims, J.; Sinev, V.; Stanton, N.; Stancu, I.; Stefanski, R.; Seukane, F.; Sugiyama, H.; Sukhotin, S.; Sumiyoshi, T.; Svoboda, R.; Talaga, R.; Tamura, N.; Tanimoto, M.; Thron, J.; von Toerne, E.; Vignaud, D.; Wagner, C.; Wang, Y.F.; Wang, Z.; Winter, W.; Wong, H.; Yakushev, E.; Yang, C.G.; Yasuda, O.

    2004-02-26

    There has been superb progress in understanding the neutrino sector of elementary particle physics in the past few years. It is now widely recognized that the possibility exists for a rich program of measuring CP violation and matter effects in future accelerator {nu} experiments, which has led to intense efforts to consider new programs at neutrino superbeams, off-axis detectors, neutrino factories and beta beams. However, the possibility of measuring CP violation can be fulfilled only if the value of the neutrino mixing parameter {theta}{sub 13} is such that sin{sup 2} (2{theta}{sub 13}) greater than or equal to on the order of 0.01. The authors of this white paper are an International Working Group of physicists who believe that a timely new experiment at a nuclear reactor sensitive to the neutrino mixing parameter {theta}{sub 13} in this range has a great opportunity for an exciting discovery, a non-zero value to {theta}{sub 13}. This would be a compelling next step of this program. We are studying possible new reactor experiments at a variety of sites around the world, and we have collaborated to prepare this document to advocate this idea and describe some of the issues that are involved.

  11. Transient Global Amnesia Deteriorates the Network Efficiency of the Theta Band.

    Directory of Open Access Journals (Sweden)

    Young Ho Park

    Full Text Available Acute perturbation of the hippocampus, one of the connector hubs in the brain, is a key step in the pathophysiological cascade of transient global amnesia (TGA. We tested the hypothesis that network efficiency, meaning the efficiency of information exchange over a network, is impaired during the acute stage of TGA. Graph theoretical analysis was applied to resting-state EEG data collected from 21 patients with TGA. The EEG data were obtained twice, once during the acute stage ( 2 months after symptom onset of TGA. Characteristic path lengths and clustering coefficients of functional networks constructed using phase-locking values were computed and normalized as a function of the degree in the delta, theta, alpha, beta 1, beta 2 and gamma frequency bands of the EEG. We investigated whether the normalized characteristic path length (nCPL and normalized clustering coefficients (nCC differed significantly between the acute and resolved stages of TGA at each frequency band using the Wilcoxon signed-rank test. For networks where the nCPL or nCC differed significantly between the two stages, we also evaluated changes in the connections of the brain networks. During the acute stage of TGA, the nCPL of the theta band networks with mean degrees of 8, 8.5, 9 and 9.5 significantly increased (P < 0.05. During the acute stage, the lost edges for these networks were mostly found between the anterior (frontal and anterior temporal and posterior (parieto-occipital and posterior temporal brain regions, whereas newly developed edges were primarily found between the left and right frontotemporal regions. The nCC of the theta band with a mean degree of 5.5 significantly decreased during the acute stage (P < 0.05. Our results indicate that TGA deteriorates the network efficiency of the theta frequency band. This effect might be related to the desynchronization between the anterior and posterior brain areas.

  12. TAO/TRITON, RAMA, and PIRATA Buoys, Quarterly, 1992-present, Sigma-Theta

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has quarterly Sigma-Theta (Potential Density Anomaly) data from the TAO/TRITON (Pacific Ocean, https://www.pmel.noaa.gov/gtmba/ ), RAMA (Indian Ocean,...

  13. Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory

    OpenAIRE

    Masahiro eKawasaki; Masahiro eKawasaki; Masahiro eKawasaki; Keiichi eKitajo; Keiichi eKitajo; Yoko eYamaguchi

    2014-01-01

    In humans, theta phase (4–8 Hz) synchronization observed on electroencephalography (EEG) plays an important role in the manipulation of mental representations during working memory (WM) tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from...

  14. Investigation of plasma turbulence in a theta-pinch-discharge

    International Nuclear Information System (INIS)

    Lins, G.

    1980-01-01

    This thesis is concerned with investigations of plasma turbulence in a 3 KJ Theta-Pinch during implosion by high-frequency Stark-effect and Thomson scattering. The next points are modifications of electron-distribution function by ionization in low preionizized turbulent plasma and energy losses by particle flow and heat flow at the ends. (HT)

  15. Measuring $\\theta_{13}$ via Muon Neutrino to Electron Neutrino Oscillations in the MINOS Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Toner, Ruth B. [Univ. of Cambridge (United Kingdom). Pembroke College

    2011-01-01

    One of the primary goals in neutrino physics at the present moment is to make a measurement of the neutrino oscillation parameter $\\theta_{13}$. This parameter, in addition to being unknown, could potentially allow for the introduction of CP violation into the lepton sector. The MINOS long-baseline neutrino oscillation experiment has the ability to make a measurement of this parameter, by looking for the oscillation of muon neutrinos to electron neutrinos between a Near and Far Detector over a distance of 735 km. This thesis discusses the development of an analysis framework to search for this oscillation mode. Two major improvements to pre-existing analysis techniques have been implemented by the author. First, a novel particle ID technique based on strip topology, known as the Library Event Matching (LEM) method, is optimized for use in MINOS. Second, a multiple bin likelihood method is developed to fit the data. These two improvements, when combined, increase MINOS' sensitivity to $\\sin^2(2\\theta_{13})$ by 27\\% over previous analyses. This thesis sees a small excess over background in the Far Detector. A Frequentist interpretation of the data rules out $\\theta_{13}=0$ at 91\\%. A Bayesian interpretation of the data is also presented, placing the most stringent upper boundary on the oscillation parameter to date, at $\\sin^2(2\\theta_{13})<0.09(0.015)$ for the Normal (Inverted) Hierarchy and $\\delta_{CP}=0$.

  16. Operating point considerations for the Reference Theta-Pinch Reactor (RTPR)

    International Nuclear Information System (INIS)

    Krakowski, R.A.; Miller, R.L.; Hagenson, R.L.

    1976-01-01

    Aspects of the continuing engineering design-point reassessment and optimization of the Reference Theta-Pinch Reactor (RTPR) are discussed. An updated interim design point which achieves a favorable energy balance and involves relaxed technological requirements, which nonetheless satisfy more rigorous physics and engineering constraints, is presented

  17. Gamma-irradiation of pupae of the house fly musca domestica L., and adult survival

    International Nuclear Information System (INIS)

    Guneidy, A.M.; Abdu, R.M.; Hamed, M.S.

    1975-01-01

    Effects of gamma-irradiation on pupae of the house fly, Musca domestica L., were determined. Pupae of 1, 2, 3, 4 and 5-day old, when exposed to a single dose of gamma rays, showed that the younger pupae were more susceptible than older pupae. The 1- and 2-day age groups were fully susceptible to all levels of treatment where no emergence was observed. The 3-day and 4-day age groups were of equal susceptibility to irradiation where emergence of 23.50% and 24.84%, respectively, was recorded at 5 Kr only. Pupae failed to emerge at dosages of 10, 15 and 25 Kr. Emergence was observed at all dosages in the 5-day old group of pupae where there was a correlation between dosage and emergence. At 5 Kr and 10 Kr, 85% and 66.36% of flies, respectively, emerged. This figure declined to 22.54% at 15 Kr and 4.09% at 25 Kr. Males were less susceptible than females. Flies of both sexes emerging from irradiated pupae died earlier than the control flies

  18. Optical design and performance of F-Theta lenses for high-power and high-precision applications

    Science.gov (United States)

    Yurevich, V. I.; Grimm, V. A.; Afonyushkin, A. A.; Yudin, K. V.; Gorny, S. G.

    2015-09-01

    F-Theta lenses are widely used in remote laser processing. Nowadays, a large variety of scanning systems utilizing these devices are commercially available. In this paper, we demonstrate that all practical issues lose their triviality in designing high-performance F-Theta scanning systems. Laser power scaling requires attention to thermally-induced phenomena and ghost reflections. This requirement considerably complicates optimization of the optical configuration of the system and primary aberration correction, even during preliminary design. Obtaining high positioning accuracy requires taking into consideration all probable reasons for processing field distortion. We briefly describe the key engineering relationships and invariants as well as the typical design of a scanner lens and the main field-flattening techniques. Specific emphasis is directed to consideration of the fundamental nonlinearity of two-mirror scanners. To the best of our knowledge, this issue has not been yet studied. We also demonstrate the benefits of our F-Theta lens optimization technique, which uses a plurality of entrance pupils. The problems of eliminating focused ghost reflections and the effects of thermally-induced processes in high-power F-Theta lenses are considered. A set of multi-path 3D processing and laser cutting experiments were conducted and are presented herein to demonstrate the impact of laser beam degradation on the process performance. A selection of our non-standard optical designs is presented.

  19. High-Field Nb3Sn Cos-theta Dipole with Stress Management

    Energy Technology Data Exchange (ETDEWEB)

    Novitski, Igor [Fermilab; Carmichael, Justin [Fermilab; Kashikhin, Vadim V. [Fermilab; Zlobin, Alexander V. [Fermilab

    2017-01-01

    Cost-effective superconducting dipole magnets with operating fields up to 16 T are being considered for the LHC en-ergy upgrade (HE-LHC) and a Future Circular Collider (FCC). To demonstrate feasibility of 15 T accelerator quality dipole mag-nets, FNAL as a part of the US-MDP is developing a single-aper-ture Nb3Sn dipole demonstrator based on a 4-layer graded cos-theta coil with 60 mm aperture and cold iron yoke. In parallel, to explore the limit of the Nb3Sn accelerator magnet technology, op-timize magnet design and performance parameters, and reduce magnet cost, magnet design studies are also being performed to push the nominal bore field to 16 T in a 60-mm aperture cos-theta dipole. Results of these studies are reported and discussed in this paper.

  20. Instability study during implosion in the Tupa Theta-Pinch

    International Nuclear Information System (INIS)

    Kayama, M.E.; Boeckelmann, H.K.

    1986-01-01

    The importance of instabilities which occur during plasma heating in a Theta Pinch, in the implosion phase, is analysed. The plasma diagnostic was done by ultrafast photography and diamagnetic probe. The implosion time and the current layer thickness were calculated using a hybrid code for plasma simulation. The theoretical data were compared with the experimental ones. (M.C.K.) [pt

  1. A theory of alpha/theta neurofeedback, creative performance enhancement, long distance functional connectivity and psychological integration.

    Science.gov (United States)

    Gruzelier, John

    2009-02-01

    Professionally significant enhancement of music and dance performance and mood has followed training with an EEG-neurofeedback protocol which increases the ratio of theta to alpha waves using auditory feedback with eyes closed. While originally the protocol was designed to induce hypnogogia, a state historically associated with creativity, the outcome was psychological integration, while subsequent applications focusing on raising the theta-alpha ratio, reduced depression and anxiety in alcoholism and resolved post traumatic stress syndrome (PTSD). In optimal performance studies we confirmed associations with creativity in musical performance, but effects also included technique and communication. We extended efficacy to dance and social anxiety. Diversity of outcome has a counterpart in wide ranging associations between theta oscillations and behaviour in cognitive and affective neuroscience: in animals with sensory-motor activity in exploration, effort, working memory, learning, retention and REM sleep; in man with meditative concentration, reduced anxiety and sympathetic autonomic activation, as well as task demands in virtual spatial navigation, focussed and sustained attention, working and recognition memory, and having implications for synaptic plasticity and long term potentiation. Neuroanatomical circuitry involves the ascending mescencephalic-cortical arousal system, and limbic circuits subserving cognitive as well as affective/motivational functions. Working memory and meditative bliss, representing cognitive and affective domains, respectively, involve coupling between frontal and posterior cortices, exemplify a role for theta and alpha waves in mediating the interaction between distal and widely distributed connections. It is posited that this mediation in part underpins the integrational attributes of alpha-theta training in optimal performance and psychotherapy, creative associations in hypnogogia, and enhancement of technical, communication and

  2. Cortico-pontine theta carrier frequency phase shift across sleep/wake states following monoaminergic lesion in rat.

    Science.gov (United States)

    Kalauzi, Aleksandar; Spasic, Sladjana; Petrovic, Jelena; Ciric, Jelena; Saponjic, Jelena

    2012-06-01

    This study was aimed to explore the sleep/wake states related cortico-pontine theta carrier frequency phase shift following a systemically induced chemical axotomy of the monoaminergic afferents within a brain of the freely moving rats. Our experiments were performed in 14 adult, male Sprague Dawley rats, chronically implanted for sleep recording. We recorded sleep during baseline condition, following sham injection (saline i.p. 1 ml/kg), and every week for 5 weeks following injection of the systemic neurotoxins (DSP-4 or PCA; 1 ml/kg, i.p.) for chemical axotomy of the locus coeruleus (LC) and dorsal raphe (DR) axon terminals. After sleep/wake states identification, FFT analysis was performed on 5 s epochs. Theta carrier frequency phase shift (∆Φ) was calculated for each epoch by averaging theta Fourier component phase shifts, and the ∆Φ values were plotted for each rat in control condition and 28 days following the monoaminergic lesions, as a time for permanently established DR or LC chemical axotomy. Calculated group averages have shown that ∆Φ increased between pons and cortex significantly in all sleep/wake states (Wake, NREM and REM) following the monoaminergic lesions, with respect to controls. Monoaminergic lesions established the pontine leading role in the brain theta oscillations during all sleep/wake states.

  3. Increased coherence among striatal regions in the theta range during attentive wakefulness

    Directory of Open Access Journals (Sweden)

    G. Lepski

    2012-08-01

    Full Text Available The striatum, the largest component of the basal ganglia, is usually subdivided into associative, motor and limbic components. However, the electrophysiological interactions between these three subsystems during behavior remain largely unknown. We hypothesized that the striatum might be particularly active during exploratory behavior, which is presumably associated with increased attention. We investigated the modulation of local field potentials (LFPs in the striatum during attentive wakefulness in freely moving rats. To this end, we implanted microelectrodes into different parts of the striatum of Wistar rats, as well as into the motor, associative and limbic cortices. We then used electromyograms to identify motor activity and analyzed the instantaneous frequency, power spectra and partial directed coherence during exploratory behavior. We observed fine modulation in the theta frequency range of striatal LFPs in 92.5 ± 2.5% of all epochs of exploratory behavior. Concomitantly, the theta power spectrum increased in all striatal channels (P 0.7 between the primary motor cortex and the rostral part of the caudatoputamen nucleus, as well as among all striatal channels (P < 0.001. Conclusively, we observed a pattern of strong theta band activation in the entire striatum during attentive wakefulness, as well as a strong coherence between the motor cortex and the entire striatum. We suggest that this activation reflects the integration of motor, cognitive and limbic systems during attentive wakefulness.

  4. Transient loss of plasma from a theta pinch having an initially reversed magnetic field

    International Nuclear Information System (INIS)

    Heidrich, J.E.

    1981-01-01

    The results of an experimental study of the transient loss of plasma from a 25-cm-long theta pinch initially containing a reversed trapped magnetic field are presented. The plasma, amenable to MHD analyses, was a doubly ionized helium plasma characterized by an ion density N/sub i/ = 2 x 10 16 cm -3 and an ion temperature T/sub i/ = 15 eV at midcoil and by N/sub i/ = 0.5 x 10 16 cm -3 and T/sub i/ = 6 eV at a position 2.5 cm beyond the end of the theta coil

  5. Validation Study of CODES Dragonfly Network Model with Theta Cray XC System

    Energy Technology Data Exchange (ETDEWEB)

    Mubarak, Misbah [Argonne National Lab. (ANL), Argonne, IL (United States); Ross, Robert B. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-05-31

    This technical report describes the experiments performed to validate the MPI performance measurements reported by the CODES dragonfly network simulation with the Theta Cray XC system at the Argonne Leadership Computing Facility (ALCF).

  6. FG7142, yohimbine, and βCCE produce anxiogenic-like effects in the elevated plus-maze but do not affect brainstem activated hippocampal theta.

    Science.gov (United States)

    Yeung, Michelle; Lu, Lily; Hughes, Adam M; Treit, Dallas; Dickson, Clayton T

    2013-12-01

    The neurobiological underpinnings of anxiety are of paramount importance to selective and efficacious pharmaceutical intervention. Hippocampal theta frequency in urethane anaesthetized rats is suppressed by all known (and some previously unknown) anti-anxiety (anxiolytic) drugs. Although these findings support the predictive validity of this assay, its construct validity (i.e., whether theta frequency actually indexes anxiety per se) has not been a subject of systematic investigation. We reasoned that if anxiolytic drugs suppress hippocampal theta frequency, then drugs that increase anxiety (i.e., anxiogenic agents) should increase theta frequency, thus providing evidence of construct validity. We used three proven anxiogenic drugs--two benzodiazepine receptor inverse agonists, N-methyl-β-carboline-3-carboxamide (FG7142) and β-carboline-3-carboxylate ethyl ester (βCCE), and one α2 noradrenergic receptor antagonist, 17α-hydroxy-yohimban-16α-carboxylic acid methyl ester (yohimbine) as pharmacological probes to assess the construct validity of the theta model. Although all three anxiogenic drugs significantly increased behavioural measures of anxiety in the elevated plus-maze, none of the three increased the frequency of hippocampal theta oscillations in the neurophysiological model. As a positive control, we demonstrated that diazepam, a proven anxiolytic drug, decreased the frequency of hippocampal theta, as in all other studies using this model. Given this discrepancy between the significant effects of anxiogenic drugs in the behavioural model and the null effects of these drugs in the neurophysiological model, we conclude that the construct validity of the hippocampal theta model of anxiety is questionable. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Theta-Cream trademark versus Bepanthol trademark lotion in breast cancer patients under radiotherapy. A new prophylactic agent in skin care?

    International Nuclear Information System (INIS)

    Roeper, B.; Kaisig, D.; Auer, F.; Mergen, E.; Molls, M.

    2004-01-01

    Background and purpose: in radiotherapy of the breast following breast-conserving surgery, the adverse reaction predominatly found is confined to the skin. After phase II studies, Theta-Cream trademark , containing CM glucan, hydroxyprolisilan C und matrixyl as active substances, was said to have prophylactic properties of preventing acute radiation side effects in skin tissue. In a prospective randomized study, Theta-Cream trademark was compared with standard skin care using Bepanthol trademark lotion. Patients and methods: 20 breast cancer patients were randomly assigned to use Theta-Cream trademark or Bepanthol trademark lotion during radiotherapy. At 0, 30, and 50 Gy, acute skin toxicity was scored with a modified RTOG scoring system. The patients' content with the skin care and the technical assistants' content with the skin marks were recorded. Results: for single aspects of toxicity and their sums in defined skin areas, no differences in median and range between study groups were found. The maximal toxicity anywhere in the breast averaged in a moderate erythema, mild elevation of skin temperature, no desquamation in both groups. Mild itchiness and sporadic efflorescences more frequently seen with Theta-Cream trademark . According to a ranking of anonymized breast photos at 50 Gy by independent investigators, side effects were equal. Patients' content was high with both skin care regimens (1.25 on a scale from 0 to 10). With Theta-Cream trademark a trend toward worse skin marks was noted. Adverse events exclusively occurred in Theta-Cream trademark users: suspected allergic reaction once, and the necessity for resimulation twice. Conclusion: in direct comparison with dexpanthenol-containing lotion, no advantage for Theta-Cream trademark was found. Higher costs and problems with skin marks prevent a general recommendation. (orig.)

  8. A spectroscopic study of radiation produced in a theta-pinch

    International Nuclear Information System (INIS)

    Trigueiros, A.; Machida, M.; Pagan, C.J.B.

    1988-01-01

    Preliminary results of the analysis of the spectra of four times ionized Krypton, Kr-V, are presented. 28 transitions were classified and for five of then the classification is new. We also present the UNICAMP theta-pinch for the study of highly ionized atoms. This device is now in testing. (author) [pt

  9. Theta-paced flickering between place-cell maps in the hippocampus

    Czech Academy of Sciences Publication Activity Database

    Ježek, Karel; Henriksen, E. J.; Treves, A.; Moser, E. I.; Moser, M.B.

    2011-01-01

    Roč. 478, č. 7368 (2011), s. 246-249 ISSN 0028-0836 R&D Projects: GA MŠk(CZ) LC554; GA MŠk(CZ) 1M0517 Institutional research plan: CEZ:AV0Z50110509 Keywords : memory * theta * hippocampus * place cells * teleportation Subject RIV: FH - Neurology Impact factor: 36.280, year: 2011

  10. Corticostriatal field potentials are modulated at delta and theta frequencies during interval-timing task in rodents

    Directory of Open Access Journals (Sweden)

    Eric B Emmons

    2016-04-01

    Full Text Available Organizing movements in time is a critical and highly conserved feature of mammalian behavior. Temporal control of action requires corticostriatal networks. We investigate these networks in rodents using a two-interval timing task while recording local field potentials in medial frontal cortex or dorsomedial striatum. Consistent with prior work, we found cue-triggered delta (1-4 Hz and theta activity (4-8 Hz primarily in rodent medial frontal cortex. We observed delta activity across temporal intervals in medial frontal cortex and dorsomedial striatum. Rewarded responses were associated with increased delta activity in medial frontal cortex. Activity in theta bands in medial frontal cortex and delta bands in the striatum was linked with the timing of responses. These data suggest both delta and theta activity in frontostriatal networks are modulated during interval timing and that activity in these bands may be involved in the temporal control of action.

  11. Increased theta band EEG power in sickle cell disease patients

    Directory of Open Access Journals (Sweden)

    Case M

    2017-12-01

    Full Text Available Michelle Case,1 Sina Shirinpour,1 Huishi Zhang,1 Yvonne H Datta,2 Stephen C Nelson,3 Karim T Sadak,4 Kalpna Gupta,2 Bin He1,5 1Department of Biomedical Engineering, 2Department of Medicine, University of Minnesota, 3Pediatric Hematology-Oncology, Children’s Hospitals and Clinics of Minnesota, 4Pediatric Hematology-Oncology, University of Minnesota Masonic Children’s Hospital, 5Institute for Engineering in Medicine, University of Minnesota, Minneapolis, MN, USA Objective: Pain is a major issue in the care of patients with sickle cell disease (SCD. The mechanisms behind pain and the best way to treat it are not well understood. We studied how electroencephalography (EEG is altered in SCD patients. Methods: We recruited 20 SCD patients and compared their resting state EEG to that of 14 healthy controls. EEG power was found across frequency bands using Welch’s method. Electrophysiological source imaging was assessed for each frequency band using the eLORETA algorithm. Results: SCD patients had increased theta power and decreased beta2 power compared to controls. Source localization revealed that areas of greater theta band activity were in areas related to pain processing. Imaging parameters were significantly correlated to emergency department visits, which indicate disease severity and chronic pain intensity. Conclusion: The present results support the pain mechanism referred to as thalamocortical dysrhythmia. This mechanism causes increased theta power in patients. Significance: Our findings show that EEG can be used to quantitatively evaluate differences between controls and SCD patients. Our results show the potential of EEG to differentiate between different levels of pain in an unbiased setting, where specific frequency bands could be used as biomarkers for chronic pain. Keywords: sickle cell disease, electroencephalography, chronic pain, electrophysiological source imaging, thalamocortical dysrhythmia

  12. Factibilidad del empleo de hongos entomopatógenos en el control de Musca domestica l. en paisajes antropizados del Noroeste de Michoacán, México.

    OpenAIRE

    García Munguía, Carlos Alberto

    2016-01-01

    El objetivo de la presente investigación fue seleccionar aislamientos de los hongos M. anisopliae y B. bassiana capaces de colonizar y controlar adultos y larvas de Musca domestica e identificar las condiciones ambientales de temperatura y humedad relativa favorables para su empleo. B. bassiana y M. anisopliae fueron transmitidos sexualmente en M. domestica usando 1, 5 y 10 machos vírgenes de 3 dias de edad, expuestos a 6 x 108 conidias mL- 1 de hongos los cuales fueron confinados con 30 hemb...

  13. Pulsars in binary systems: probing binary stellar evolution and general relativity.

    Science.gov (United States)

    Stairs, Ingrid H

    2004-04-23

    Radio pulsars in binary orbits often have short millisecond spin periods as a result of mass transfer from their companion stars. They therefore act as very precise, stable, moving clocks that allow us to investigate a large set of otherwise inaccessible astrophysical problems. The orbital parameters derived from high-precision binary pulsar timing provide constraints on binary evolution, characteristics of the binary pulsar population, and the masses of neutron stars with different mass-transfer histories. These binary systems also test gravitational theories, setting strong limits on deviations from general relativity. Surveys for new pulsars yield new binary systems that increase our understanding of all these fields and may open up whole new areas of physics, as most spectacularly evidenced by the recent discovery of an extremely relativistic double-pulsar system.

  14. Antimicrobial activity of alcohols from Musca domestica.

    Science.gov (United States)

    Gołębiowski, Marek; Dawgul, Małgorzata; Kamysz, Wojciech; Boguś, Mieczysława I; Wieloch, Wioletta; Włóka, Emilia; Paszkiewicz, Monika; Przybysz, Elżbieta; Stepnowski, Piotr

    2012-10-01

    Information on the stimulatory and inhibitory effects of cuticular alcohols on growth and virulence of insecticidal fungi is unavailable. Therefore, we set out to describe the content of cuticular and internal alcohols in the body of housefly larvae, pupae, males and females. The total cuticular alcohols in larvae, males and females of Musca domestica were detected in comparable amounts (4.59, 3.95 and 4.03 μg g(-1) insect body, respectively), but occurred in smaller quantities in pupae (2.16 μg g(-1)). The major free alcohol in M. domestica larvae was C(12:0) (70.4%). Internal alcohols of M. domestica larvae were not found. Among cuticular pupae alcohols, C(12:0) (31.0%) was the most abundant. In the internal lipids of pupae, only five alcohols were identified in trace amounts. The most abundant alcohol in males was C(24:0) (57.5%). The percentage content of cuticular C(24:0) in males and females (57.5 and 36.5%, respectively) was significantly higher than that of cuticular lipids in larvae and pupae (0.9 and 5.6%, respectively). Only two alcohols were present in the internal lipids of males in trace amounts (C(18:0) and C(20:0)). The most abundant cuticular alcohols in females were C(24:0) (36.5%) and C(12:0) (26.8%); only two alcohols (C(18:0) and C(20:0)) were detected in comparable amounts in internal lipids (3.61±0.32 and 5.01±0.42 μg g(-1), respectively). For isolated alcohols, antimicrobial activity against 10 reference strains of bacteria and fungi was determined. Individual alcohols showed approximately equal activity against fungal strains. C(14:0) was effective against gram-positive bacteria, whereas gram-negative bacteria were resistant to all tested alcohols. Mixtures of alcohols found in cuticular lipids of larvae, pupae, males and females of M. domestica generally presented higher antimicrobial activity than individual alcohols. In contrast, crude extracts containing both cuticular and internal lipids showed no antifungal activity against the

  15. Efficacy and Time Course of Theta Burst Stimulation in Healthy Humans

    NARCIS (Netherlands)

    Wischnewski, M.; Schutter, D.J.L.G.

    2015-01-01

    BACKGROUND: In the past decade research has shown that continuous (cTBS) and intermittent theta burst stimulation (iTBS) alter neuronal excitability levels in the primary motor cortex. OBJECTIVE: Quantitatively review the magnitude and time course on cortical excitability of cTBS and iTBS. METHODS:

  16. Field reversed theta pinch TC-I UNICAMP

    International Nuclear Information System (INIS)

    Honda, R.Y.; Machida, M.; Aramaki, E.A.; Porto, P.; Berni, L.A.

    1990-01-01

    Field reversed configuration TC-I device is 16 cm diameter, 1 meter long with two mirror coils and 30 kJ field reversed theta pinch working for over two years at University of Campinas. Its implosion dynamics and field reversal parameters have been studied using flux excluded loops, internal magnetic probe, visible spectroscopy, photodiode array and image converter camera. The vacuum vessel is a pyrex tube of 14,5 cm diameter pumped with a liquid nitrogen cooled diffusion pump to a base pressure of 6 x 10 -7 Torr. The schematic view of the machine and experimental set up are shown. (Author)

  17. Trojan Binaries

    Science.gov (United States)

    Noll, K. S.

    2017-12-01

    The Jupiter Trojans, in the context of giant planet migration models, can be thought of as an extension of the small body populations found beyond Neptune in the Kuiper Belt. Binaries are a distinctive feature of small body populations in the Kuiper Belt with an especially high fraction apparent among the brightest Cold Classicals. The binary fraction, relative sizes, and separations in the dynamically excited populations (Scattered, Resonant) reflects processes that may have eroded a more abundant initial population. This trend continues in the Centaurs and Trojans where few binaries have been found. We review new evidence including a third resolved Trojan binary and lightcurve studies to understand how the Trojans are related to the small body populations that originated in the outer protoplanetary disk.

  18. Differential effects of ongoing EEG beta and theta power on memory formation.

    Science.gov (United States)

    Scholz, Sebastian; Schneider, Signe Luisa; Rose, Michael

    2017-01-01

    Recently, elevated ongoing pre-stimulus beta power (13-17 Hz) at encoding has been associated with subsequent memory formation for visual stimulus material. It is unclear whether this activity is merely specific to visual processing or whether it reflects a state facilitating general memory formation, independent of stimulus modality. To answer that question, the present study investigated the relationship between neural pre-stimulus oscillations and verbal memory formation in different sensory modalities. For that purpose, a within-subject design was employed to explore differences between successful and failed memory formation in the visual and auditory modality. Furthermore, associative memory was addressed by presenting the stimuli in combination with background images. Results revealed that similar EEG activity in the low beta frequency range (13-17 Hz) is associated with subsequent memory success, independent of stimulus modality. Elevated power prior to stimulus onset differentiated successful from failed memory formation. In contrast, differential effects between modalities were found in the theta band (3-7 Hz), with an increased oscillatory activity before the onset of later remembered visually presented words. In addition, pre-stimulus theta power dissociated between successful and failed encoding of associated context, independent of the stimulus modality of the item itself. We therefore suggest that increased ongoing low beta activity reflects a memory promoting state, which is likely to be moderated by modality-independent attentional or inhibitory processes, whereas high ongoing theta power is suggested as an indicator of the enhanced binding of incoming interlinked information.

  19. Theta and Alpha Alterations in Amnestic Mild Cognitive Impairment in Semantic Go/NoGo Tasks

    Directory of Open Access Journals (Sweden)

    Lydia T. Nguyen

    2017-05-01

    Full Text Available Growing evidence suggests that cognitive control processes are impaired in amnestic mild cognitive impairment (aMCI; however the nature of these alterations needs further examination. The current study examined differences in electroencephalographic theta and alpha power related to cognitive control processes involving response execution and response inhibition in 22 individuals with aMCI and 22 age-, sex-, and education-matched cognitively normal controls. Two Go/NoGo tasks involving semantic categorization were used. In the basic categorization task, Go/NoGo responses were made based on exemplars of a single car (Go and a single dog (NoGo. In the superordinate categorization task, responses were made based on multiple exemplars of objects (Go and animals (NoGo. Behavioral data showed that the aMCI group had more false alarms during the NoGo trials compared to controls. The EEG data revealed between group differences related to response type in theta (4–7 Hz and low-frequency alpha (8–10 Hz power. In particular, the aMCI group differed from controls in theta power during the NoGo trials at frontal and parietal electrodes, and in low-frequency alpha power during Go trials at parietal electrodes. These results suggest that alterations in theta power converge with behavioral deterioration in response inhibition, whereas alterations in low-frequency alpha power appear to precede behavioral changes in response execution. Both behavioral and electrophysiological correlates combined provide a more comprehensive characterization of cognitive control deficits in aMCI.

  20. The effects of individualized theta burst stimulation on the excitability of the human motor system.

    Science.gov (United States)

    Brownjohn, Philip W; Reynolds, John N J; Matheson, Natalie; Fox, Jonathan; Shemmell, Jonathan B H

    2014-01-01

    Theta burst stimulation (TBS) is a pattern of repetitive transcranial magnetic stimulation that has been demonstrated to facilitate or suppress human corticospinal excitability when applied intermittently (iTBS) or continuously (cTBS), respectively. While the fundamental pattern of TBS, consisting of bursts of 50 Hz stimulation repeated at a 5 Hz theta frequency, induces synaptic plasticity in animals and in vitro preparations, the relationship between TBS and underlying cortical firing patterns in the human cortex has not been elucidated. To compare the effects of 5 Hz iTBS and cTBS with individualized TBS paradigms on corticospinal excitability and intracortical inhibitory circuits. Participants received standard and individualized iTBS (iTBS 5; iTBS I) and cTBS (cTBS 5; cTBS I), and sham TBS, in a randomised design. For individualized paradigms, the 5 Hz theta component of the TBS pattern was replaced by the dominant cortical frequency (4-16 Hz; upper frequency restricted by technical limitations) for each individual. We report that iTBS 5 and iTBS I both significantly facilitated motor evoked potential (MEP) amplitude to a similar extent. Unexpectedly, cTBS 5 and cTBS I failed to suppress MEP amplitude. None of the active TBS protocols had any significant effects on intracortical circuits when compared with sham TBS. In summary, iTBS facilitated MEP amplitude, an effect that was not improved by individualizing the theta component of the TBS pattern, while cTBS, a reportedly inhibitory paradigm, produced no change, or facilitation of MEP amplitude in our hands. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Testing the Binary Black Hole Nature of a Compact Binary Coalescence.

    Science.gov (United States)

    Krishnendu, N V; Arun, K G; Mishra, Chandra Kant

    2017-09-01

    We propose a novel method to test the binary black hole nature of compact binaries detectable by gravitational wave (GW) interferometers and, hence, constrain the parameter space of other exotic compact objects. The spirit of the test lies in the "no-hair" conjecture for black holes where all properties of a Kerr black hole are characterized by its mass and spin. The method relies on observationally measuring the quadrupole moments of the compact binary constituents induced due to their spins. If the compact object is a Kerr black hole (BH), its quadrupole moment is expressible solely in terms of its mass and spin. Otherwise, the quadrupole moment can depend on additional parameters (such as the equation of state of the object). The higher order spin effects in phase and amplitude of a gravitational waveform, which explicitly contains the spin-induced quadrupole moments of compact objects, hence, uniquely encode the nature of the compact binary. Thus, we argue that an independent measurement of the spin-induced quadrupole moment of the compact binaries from GW observations can provide a unique way to distinguish binary BH systems from binaries consisting of exotic compact objects.

  2. Binary Masking & Speech Intelligibility

    DEFF Research Database (Denmark)

    Boldt, Jesper

    The purpose of this thesis is to examine how binary masking can be used to increase intelligibility in situations where hearing impaired listeners have difficulties understanding what is being said. The major part of the experiments carried out in this thesis can be categorized as either experime......The purpose of this thesis is to examine how binary masking can be used to increase intelligibility in situations where hearing impaired listeners have difficulties understanding what is being said. The major part of the experiments carried out in this thesis can be categorized as either...... experiments under ideal conditions or as experiments under more realistic conditions useful for real-life applications such as hearing aids. In the experiments under ideal conditions, the previously defined ideal binary mask is evaluated using hearing impaired listeners, and a novel binary mask -- the target...... binary mask -- is introduced. The target binary mask shows the same substantial increase in intelligibility as the ideal binary mask and is proposed as a new reference for binary masking. In the category of real-life applications, two new methods are proposed: a method for estimation of the ideal binary...

  3. Plasma resistivity in a slow rising current theta-pinch device

    International Nuclear Information System (INIS)

    Kayama, Milton Eiji; Dobrowolsky, Marcelo Shubert; Honda, Roberto Yzumi; Aramaki, Emilia Akemi; Algatti, Mauricio Antonio

    1998-01-01

    Anomalous behavior of plasma resistivity was observed in a Theta-pinch plasma. A comparative analysis was performed with a hybrid numerical code where the Chodura s resistivity algorithm is included. Good agreement was found in the radial plasma dynamic description. The experimental value of resistivity at null field point was found to be one order of magnitude greater than the theoretical prediction. (author)

  4. Interacting binary stars

    CERN Document Server

    Sahade, Jorge; Ter Haar, D

    1978-01-01

    Interacting Binary Stars deals with the development, ideas, and problems in the study of interacting binary stars. The book consolidates the information that is scattered over many publications and papers and gives an account of important discoveries with relevant historical background. Chapters are devoted to the presentation and discussion of the different facets of the field, such as historical account of the development in the field of study of binary stars; the Roche equipotential surfaces; methods and techniques in space astronomy; and enumeration of binary star systems that are studied

  5. Insights on the neural basis of motor plasticity induced by theta burst stimulation from TMS-EEG

    Science.gov (United States)

    VERNET, Marine; BASHIR, Shahid; YOO, Woo-Kyoung; PEREZ, Jennifer M.; NAJIB, Umer; PASCUAL-LEONE, Alvaro

    2014-01-01

    Transcranial magnetic stimulation (TMS) is a useful tool to induce and measure plasticity in the human brain. However, the cortical effects are generally indirectly evaluated with motor-evoked potentials (MEPs) reflective of modulation of cortico-spinal excitability. In this study, we aim to provide direct measures of cortical plasticity by combining TMS with electroencephalography (EEG). Continuous theta-burst stimulation (cTBS) was applied over the primary motor cortex (M1) of young healthy adults; and we measured modulation of (i) motor evoked-potentials (MEPs), (ii) TMS-induced EEG evoked potentials (TEPs), (iii) TMS-induced EEG synchronization and (iv) eyes-closed resting EEG. Our results show the expected cTBS-induced decrease in MEPs size, which we found to be paralleled by a modulation of a combination of TEPs. Furthermore, we found that cTBS increased the power in the theta band of eyes-closed resting EEG, whereas it decreased single-pulse TMS-induced power in the theta and alpha bands. In addition, cTBS decreased the power in the beta band of eyes-closed resting EEG, whereas it increased single-pulse TMS-induced power in the beta band. We suggest that cTBS acts by modulating the phase alignment between already active oscillators; it synchronizes low frequency (theta and/or alpha) oscillators and desynchronizes high frequency (beta) oscillators. These results provide novel insights into the cortical effects of cTBS and could be useful for exploring cTBS-induced plasticity outside of the motor cortex. PMID:23190020

  6. Seasonal variation of Sigma sub(Theta) with wind speed, direction and stability

    Digital Repository Service at National Institute of Oceanography (India)

    Sadhuram, Y.

    For an airport site near Visakhapatnam, India, and based on 10 years of data for the months of January, April, August and October, values of Sigma sub(Theta) are given as a function of wind speed, wind direction and Pasquill diffusion category...

  7. The noncommutative standard model. Construction beyond leading order in {theta} and collider phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Alboteanu, A.M.

    2007-07-01

    Within this work we study the phenomenological consequences of a possible realization of QFT on noncommutative space-time. In the first part we performed a phenomenological analysis of the hadronic process pp {yields} Z{sub {gamma}} {yields} l{sup +}l{sup -}{gamma} at the LHC and of electron-positron pair annihilation into a Z boson and a photon at the International Linear Collider (ILC). The noncommutative extension of the SM considered within this work relies on two building blocks: the Moyal-Weyl *-product of functions on ordinary space-time and the Seiberg-Witten maps. A consequence of the noncommutativity of space-time is the violation of rotational invariance with respect to the beam axis. This effect shows up in the azimuthal dependence of cross sections, which is absent in the SM as well as in other models beyond the SM. We have found this dependence to be best suited for deriving the sensitivity bounds on the noncommutative scale NC. By studying pp{yields}Z{sub {gamma}} {yields}l{sup +}l{sup -}{gamma} to first order in the noncommutative parameter {theta}, we show in the first part of this work that measurements at the LHC are sensitive to noncommutative effects only in certain cases, giving bounds on the noncommutative scale of {lambda}{sub NC} >or similar 1.2 TeV. By means of e{sup +}e{sup -} {yields} Z{sub {gamma}} {yields} l{sup +}l{sup -}{gamma} to O({theta}) we have shown that ILC measurements are complementary to LHC measurements of the noncommutative parameters. In addition, the bounds on {lambda}{sub NC} derived from the ILC are significantly higher and reach {lambda}{sub NC} >or similar 6 TeV. In the second part of this work we expand the neutral current sector of the noncommutative SM to second order in {theta}. We found that, against the general expectation, the theory must be enlarged by additional parameters. The new parameters enter the theory as ambiguities of the Seiberg-Witten maps. The latter are not uniquely determined and differ by

  8. Lateralized theta wave connectivity and language performance in 2- to 5-year-old children.

    Science.gov (United States)

    Kikuchi, Mitsuru; Shitamichi, Kiyomi; Yoshimura, Yuko; Ueno, Sanae; Remijn, Gerard B; Hirosawa, Tetsu; Munesue, Toshio; Tsubokawa, Tsunehisa; Haruta, Yasuhiro; Oi, Manabu; Higashida, Haruhiro; Minabe, Yoshio

    2011-10-19

    Recent neuroimaging studies support the view that a left-lateralized brain network is crucial for language development in children. However, no previous studies have demonstrated a clear link between lateralized brain functional network and language performance in preschool children. Magnetoencephalography (MEG) is a noninvasive brain imaging technique and is a practical neuroimaging method for use in young children. MEG produces a reference-free signal, and is therefore an ideal tool to compute coherence between two distant cortical rhythms. In the present study, using a custom child-sized MEG system, we investigated brain networks while 78 right-handed preschool human children (32-64 months; 96% were 3-4 years old) listened to stories with moving images. The results indicated that left dominance of parietotemporal coherence in theta band activity (6-8 Hz) was specifically correlated with higher performance of language-related tasks, whereas this laterality was not correlated with nonverbal cognitive performance, chronological age, or head circumference. Power analyses did not reveal any specific frequencies that contributed to higher language performance. Our results suggest that it is not the left dominance in theta oscillation per se, but the left-dominant phase-locked connectivity via theta oscillation that contributes to the development of language ability in young children.

  9. Numerical studies of the linear theta pinch

    International Nuclear Information System (INIS)

    Brackbill, J.U.; Menzel, M.T.; Barnes, D.C.

    1975-01-01

    Aspects of several physical problems associated with linear theta pinches were studied using recently developed numerical methods for the solution of the nonlinear equations for time-dependent magnetohydrodynamic flow in two- and three-dimensions. The problems studied include the propagation of end-loss produced rarefaction waves, the flow produced in a proposed injection experiment geometry, and the linear growth and nonlinear saturation of instabilities in rotating plasmas, all in linear geometries. The studies illustrate how numerical computations aid in flow visualization, and how the small amplitude behavior and nonlinear fate of plasmas in unstable equilibria can be connected through the numerical solution of the dynamical equations. (auth)

  10. Full Ionisation In Binary-Binary Encounters With Small Positive Energies

    Science.gov (United States)

    Sweatman, W. L.

    2006-08-01

    Interactions between binary stars and single stars and binary stars and other binary stars play a key role in the dynamics of a dense stellar system. Energy can be transferred between the internal dynamics of a binary and the larger scale dynamics of the interacting objects. Binaries can be destroyed and created by the interaction. In a binary-binary encounter, full ionisation occurs when both of the binary stars are destroyed in the interaction to create four single stars. This is only possible when the total energy of the system is positive. For very small energies the probability of this occurring is very low and it tends towards zero as the total energy tends towards zero. Here the case is considered for which all the stars have equal masses. An asymptotic power law is predicted relating the probability of full ionisation with the total energy when this latter quantity is small. The exponent, which is approximately 2.31, is compared with the results from numerical scattering experiments. The theoretical approach taken is similar to one used previously in the three-body problem. It makes use of the fact that the most dramatic changes in scale and energies of a few-body system occur when its components pass near to a central configuration. The position, and number, of these configurations is not known for the general four-body problem, however, with equal masses there are known to be exactly five different cases. Separate consideration and comparison of the properties of orbits close to each of these five central configurations enables the prediction of the form of the cross-section for full ionisation for the case of small positive total energy. This is the relation between total energy and the probability of total ionisation described above.

  11. Differential effects of ongoing EEG beta and theta power on memory formation.

    Directory of Open Access Journals (Sweden)

    Sebastian Scholz

    Full Text Available Recently, elevated ongoing pre-stimulus beta power (13-17 Hz at encoding has been associated with subsequent memory formation for visual stimulus material. It is unclear whether this activity is merely specific to visual processing or whether it reflects a state facilitating general memory formation, independent of stimulus modality. To answer that question, the present study investigated the relationship between neural pre-stimulus oscillations and verbal memory formation in different sensory modalities. For that purpose, a within-subject design was employed to explore differences between successful and failed memory formation in the visual and auditory modality. Furthermore, associative memory was addressed by presenting the stimuli in combination with background images. Results revealed that similar EEG activity in the low beta frequency range (13-17 Hz is associated with subsequent memory success, independent of stimulus modality. Elevated power prior to stimulus onset differentiated successful from failed memory formation. In contrast, differential effects between modalities were found in the theta band (3-7 Hz, with an increased oscillatory activity before the onset of later remembered visually presented words. In addition, pre-stimulus theta power dissociated between successful and failed encoding of associated context, independent of the stimulus modality of the item itself. We therefore suggest that increased ongoing low beta activity reflects a memory promoting state, which is likely to be moderated by modality-independent attentional or inhibitory processes, whereas high ongoing theta power is suggested as an indicator of the enhanced binding of incoming interlinked information.

  12. Event-related theta synchronization predicts deficit in facial affect recognition in schizophrenia.

    Science.gov (United States)

    Csukly, Gábor; Stefanics, Gábor; Komlósi, Sarolta; Czigler, István; Czobor, Pál

    2014-02-01

    Growing evidence suggests that abnormalities in the synchronized oscillatory activity of neurons in schizophrenia may lead to impaired neural activation and temporal coding and thus lead to neurocognitive dysfunctions, such as deficits in facial affect recognition. To gain an insight into the neurobiological processes linked to facial affect recognition, we investigated both induced and evoked oscillatory activity by calculating the Event Related Spectral Perturbation (ERSP) and the Inter Trial Coherence (ITC) during facial affect recognition. Fearful and neutral faces as well as nonface patches were presented to 24 patients with schizophrenia and 24 matched healthy controls while EEG was recorded. The participants' task was to recognize facial expressions. Because previous findings with healthy controls showed that facial feature decoding was associated primarily with oscillatory activity in the theta band, we analyzed ERSP and ITC in this frequency band in the time interval of 140-200 ms, which corresponds to the N170 component. Event-related theta activity and phase-locking to facial expressions, but not to nonface patches, predicted emotion recognition performance in both controls and patients. Event-related changes in theta amplitude and phase-locking were found to be significantly weaker in patients compared with healthy controls, which is in line with previous investigations showing decreased neural synchronization in the low frequency bands in patients with schizophrenia. Neural synchrony is thought to underlie distributed information processing. Our results indicate a less effective functioning in the recognition process of facial features, which may contribute to a less effective social cognition in schizophrenia. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  13. Theta-Gamma Coding Meets Communication-through-Coherence: Neuronal Oscillatory Multiplexing Theories Reconciled.

    Science.gov (United States)

    McLelland, Douglas; VanRullen, Rufin

    2016-10-01

    Several theories have been advanced to explain how cross-frequency coupling, the interaction of neuronal oscillations at different frequencies, could enable item multiplexing in neural systems. The communication-through-coherence theory proposes that phase-matching of gamma oscillations between areas enables selective processing of a single item at a time, and a later refinement of the theory includes a theta-frequency oscillation that provides a periodic reset of the system. Alternatively, the theta-gamma neural code theory proposes that a sequence of items is processed, one per gamma cycle, and that this sequence is repeated or updated across theta cycles. In short, both theories serve to segregate representations via the temporal domain, but differ on the number of objects concurrently represented. In this study, we set out to test whether each of these theories is actually physiologically plausible, by implementing them within a single model inspired by physiological data. Using a spiking network model of visual processing, we show that each of these theories is physiologically plausible and computationally useful. Both theories were implemented within a single network architecture, with two areas connected in a feedforward manner, and gamma oscillations generated by feedback inhibition within areas. Simply increasing the amplitude of global inhibition in the lower area, equivalent to an increase in the spatial scope of the gamma oscillation, yielded a switch from one mode to the other. Thus, these different processing modes may co-exist in the brain, enabling dynamic switching between exploratory and selective modes of attention.

  14. Working memory performance inversely predicts spontaneous delta and theta-band scaling relations.

    Science.gov (United States)

    Euler, Matthew J; Wiltshire, Travis J; Niermeyer, Madison A; Butner, Jonathan E

    2016-04-15

    Electrophysiological studies have strongly implicated theta-band activity in human working memory processes. Concurrently, work on spontaneous, non-task-related oscillations has revealed the presence of long-range temporal correlations (LRTCs) within sub-bands of the ongoing EEG, and has begun to demonstrate their functional significance. However, few studies have yet assessed the relation of LRTCs (also called scaling relations) to individual differences in cognitive abilities. The present study addressed the intersection of these two literatures by investigating the relation of narrow-band EEG scaling relations to individual differences in working memory ability, with a particular focus on the theta band. Fifty-four healthy adults completed standardized assessments of working memory and separate recordings of their spontaneous, non-task-related EEG. Scaling relations were quantified in each of the five classical EEG frequency bands via the estimation of the Hurst exponent obtained from detrended fluctuation analysis. A multilevel modeling framework was used to characterize the relation of working memory performance to scaling relations as a function of general scalp location in Cartesian space. Overall, results indicated an inverse relationship between both delta and theta scaling relations and working memory ability, which was most prominent at posterior sensors, and was independent of either spatial or individual variability in band-specific power. These findings add to the growing literature demonstrating the relevance of neural LRTCs for understanding brain functioning, and support a construct- and state-dependent view of their functional implications. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Increased frontal electroencephalogram theta amplitude in patients with anorexia nervosa compared to healthy controls

    Directory of Open Access Journals (Sweden)

    Hestad KA

    2016-09-01

    Full Text Available Knut A Hestad,1–3 Siri Weider,3,4 Kristian Bernhard Nilsen,5–7 Marit Sæbø Indredavik,8,9 Trond Sand7,10 1Department of Research, Innlandet Hospital Trust, Brumunddal, Norway; 2Department of Public Health, Hedmark University of Applied Sciences, Elverum, Norway; 3Department of Psychology, Faculty of Social Sciences and Technology Management, Norwegian University of Science and Technology (NTNU, Trondheim, Norway; 4Department of Psychiatry, Specialised Unit for Eating Disorder Patients, Levanger Hospital, Health Trust Nord-Trøndelag, Levanger, Norway; 5Department of Neuroscience, Norwegian University of Science and Technology (NTNU, Trondheim, Norway; 6Department of Work Psychology and Physiology, National Institute of Occupational Health, Oslo, Norway; 7Department of Neurology, Section for Clinical Neurophysiology, Oslo University Hospital, Ullevål, Oslo, Norway; 8Regional Centre for Child and Youth Mental Health and Child Welfare, Faculty of Medicine, Norwegian University of Science and Technology (NTNU, Trondheim, Norway; 9Department of Child and Adolescent Psychiatry, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway; 10Department of Neurology and Clinical Neurophysiology, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway Objective: To conduct a blind study of quantitative electroencephalogram-band amplitudes in patients with anorexia nervosa (AN and healthy controls.Methods: Twenty-one patients with AN and 24 controls were examined with eyes-closed 16-channel electroencephalogram. Main variables were absolute alpha, theta, and delta amplitudes in frontal, temporal, and posterior regions.Results: There were no significant differences between the AN patients and controls regarding absolute regional band amplitudes in µV. Borderline significance was found for anterior theta (P=0.051. Significantly increased left and right frontal electrode theta amplitude was found in AN patients (F3, P=0.014; F4, P

  16. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. I. S-TYPE BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Kaltenegger, Lisa [MPIA, Koenigstuhl 17, D-69117 Heidelberg (Germany); Haghighipour, Nader, E-mail: kaltenegger@mpia.de [Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii-Manoa, Honolulu, HI 96822 (United States)

    2013-11-10

    We have developed a comprehensive methodology for calculating the boundaries of the habitable zone (HZ) of planet-hosting S-type binary star systems. Our approach is general and takes into account the contribution of both stars to the location and extent of the binary HZ with different stellar spectral types. We have studied how the binary eccentricity and stellar energy distribution affect the extent of the HZ. Results indicate that in binaries where the combination of mass-ratio and orbital eccentricity allows planet formation around a star of the system to proceed successfully, the effect of a less luminous secondary on the location of the primary's HZ is generally negligible. However, when the secondary is more luminous, it can influence the extent of the HZ. We present the details of the derivations of our methodology and discuss its application to the binary HZ around the primary and secondary main-sequence stars of an FF, MM, and FM binary, as well as two known planet-hosting binaries α Cen AB and HD 196886.

  17. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. I. S-TYPE BINARIES

    International Nuclear Information System (INIS)

    Kaltenegger, Lisa; Haghighipour, Nader

    2013-01-01

    We have developed a comprehensive methodology for calculating the boundaries of the habitable zone (HZ) of planet-hosting S-type binary star systems. Our approach is general and takes into account the contribution of both stars to the location and extent of the binary HZ with different stellar spectral types. We have studied how the binary eccentricity and stellar energy distribution affect the extent of the HZ. Results indicate that in binaries where the combination of mass-ratio and orbital eccentricity allows planet formation around a star of the system to proceed successfully, the effect of a less luminous secondary on the location of the primary's HZ is generally negligible. However, when the secondary is more luminous, it can influence the extent of the HZ. We present the details of the derivations of our methodology and discuss its application to the binary HZ around the primary and secondary main-sequence stars of an FF, MM, and FM binary, as well as two known planet-hosting binaries α Cen AB and HD 196886

  18. Reduction of Escherichia coli, Salmonella Enteritidis and Campylobacter jejuni in poultry manure by rearing of Musca domestica fly larvae

    DEFF Research Database (Denmark)

    Nordentoft, Steen; Fischer, C.; Bjerrum, L.

    2017-01-01

    A major barrier for using animal waste as substrate for production of insects for feed or food is the concern for safety of the end products. In this study we investigated how rearing of fly larvae of Musca domestica in poultry manure influenced the counts of three pathogenic test strains...... of the larvae stage. This study provides data for evaluation of feed safety of fly larvae reared on animal waste. Furthermore suggests a potential use for reduction of these pathogens in manure........ Enteritidis, and C. jejuni was faster in manure with rearing of fly larvae than in manure without larvae; an 8 log10 reduction of all three test bacteria was observed within four days in manure with larvae; compared to manure without larvae where a 1 to 2 log10 was observed. We found no sign of propagation...

  19. Isolation of fungi in Musca domestica Linnaeus, 1758 (Diptera: Muscidae captured at two natural breeding grounds in the municipality of Seropédica, Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Sales Márcia de Senna Nunes

    2002-01-01

    Full Text Available The objective of this study was to isolate and identify fungal species found in natural association with adults of Musca domestica. The adult insects were collected from two natural breeding grounds: hog pens and an urban sanitary landfill. The isolated fungi were identified as: Aspergillus flavus (23.8%, A. niger var. niger (14.4%, Penicillium corylophilum (21.4%, P. fellutanum (11.9%, Cladosporium cladosporoides (4.7%, Fusarium sp. (4.7%, Alternaria alternata (11.9%, Curvularia brachyspora (2.4%, Mycelia sterilia (2.4% and the Mucorales order (2.4%.

  20. Theta and beta oscillatory dynamics in the dentate gyrus reveal a shift in network processing state during cue encounters

    Directory of Open Access Journals (Sweden)

    Lara Maria Rangel

    2015-07-01

    Full Text Available The hippocampus is an important structure for learning and memory processes, and has strong rhythmic activity. Although a large amount of research has been dedicated towards understanding the rhythmic activity in the hippocampus during exploratory behaviors, specifically in the theta (5-10 Hz frequency range, few studies have examined the temporal interplay of theta and other frequencies during the presentation of meaningful cues. We obtained in vivo electrophysiological recordings of local field potentials (LFP in the dentate gyrus (DG of the hippocampus as rats performed three different associative learning tasks. In each task, cue presentations elicited pronounced decrements in theta amplitude in conjunction with increases in beta (15-30Hz amplitude. These changes were often transient but were sustained from the onset of cue encounters until the occurrence of a reward outcome. This oscillatory profile shifted in time to precede cue encounters over the course of the session, and was not present during similar behavior in the absence of task relevant stimuli. The observed decreases in theta amplitude and increases in beta amplitude in the dentate gyrus may thus reflect a shift in processing state that occurs when encountering meaningful cues.

  1. Interacting binaries

    CERN Document Server

    Shore, S N; van den Heuvel, EPJ

    1994-01-01

    This volume contains lecture notes presented at the 22nd Advanced Course of the Swiss Society for Astrophysics and Astronomy. The contributors deal with symbiotic stars, cataclysmic variables, massive binaries and X-ray binaries, in an attempt to provide a better understanding of stellar evolution.

  2. Using theta and alpha band power to assess cognitive workload in multitasking environments.

    Science.gov (United States)

    Puma, Sébastien; Matton, Nadine; Paubel, Pierre-V; Raufaste, Éric; El-Yagoubi, Radouane

    2018-01-01

    Cognitive workload is of central importance in the fields of human factors and ergonomics. A reliable measurement of cognitive workload could allow for improvements in human machine interface designs and increase safety in several domains. At present, numerous studies have used electroencephalography (EEG) to assess cognitive workload, reporting the rise in cognitive workload to be associated with increases in theta band power and decreases in alpha band power. However, results have been inconsistent with some failing to reach the required level of significance. We hypothesized that the lack of consistency could be related to individual differences in task performance and/or to the small sample sizes in most EEG studies. In the present study we used EEG to assess the increase in cognitive workload occurring in a multitasking environment while taking into account differences in performance. Twenty participants completed a task commonly used in airline pilot recruitment, which included an increasing number of concurrent sub-tasks to be processed from one to four. Subjective ratings, performances scores, pupil size and EEG signals were recorded. Results showed that increases in EEG alpha and theta band power reflected increases in the involvement of cognitive resources for the completion of one to three subtasks in a multitasking environment. These values reached a ceiling when performances dropped. Consistent differences in levels of alpha and theta band power were associated to levels of task performance: highest performance was related to lowest band power. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Desenvolvimento de Supputius cincticeps (Heteroptera, Pentatomidae alimentado com larvas de Zophobas confusa, Tenebrio molitor (Coleoptera, Tenebrionidae e Musca domestica (Diptera, Muscidae Development of Supputius cincticeps (Heteroptera, Pentatomidae fed with Zophobas confusa, Tenebrio molitor (Coleoptera, Tenebrionidae and Musca domestica (Diptera, Muscidae larvae

    Directory of Open Access Journals (Sweden)

    Eduardo B. Beserra

    1995-09-01

    Full Text Available Egg viability and nymphal development of the predatory bug Supputius cincticeps (Stål, 1860 were evaluated during two generations in the Biological Control Laboratory of the Núcleo de Biotecnologia Aplicada à Agropecuária (Bioagro/UFV in Viçosa (Minas Gerais, Brazil at 24.72±1.10ºC and photophase of 12 hours. Three treatments were represented by S. cincticeps fed with Zophobas confusa Gebien, 1906, Tenebrio molitor Linnaeus, 1758 and Musca domestica Linnaeus, 1758 larvae. Higher egg viability of this predator was found when the preys were Z. confusa and T. molitor, 74.46% and 80.91 %, than in M. domestica, 57.02%, but incubation period showed no differences between preys. Shorter nymphal development and higher nymphal viability were found with Z. confusa and T. molitor than with M. domestica. Higher weight increase was found for nymphs which originated males and females in the second generation specialy with the first two preys.

  4. Lexical tonal discrimination in Zapotec children. A study of the theta rhythm.

    Science.gov (United States)

    Poblano, Adrián; Castro-Sierra, Eduardo; Arteaga, Carmina; Pérez-Ruiz, Santiago J

    Zapotec is a language used mainly in the state of Oaxaca in Mexico of tonal characteristic; homophone words with difference in fundamental frequency with different meanings. Our objective was to analyze changes in the electroencephalographic (EEG) theta rhythm during word discrimination of lexical tonal bi-syllabic homophone word samples of Zapotec. We employed electroencephalography analysis during lexical tonal discrimination in 12 healthy subjects 9-16 years of age. We observed an increase in theta relative power between lexical discrimination and at rest eyes-open state in right temporal site. We also observed several significant intra- and inter-hemispheric correlations in several scalp sites, mainly in left fronto-temporal and right temporal areas when subjects were performing lexical discrimination. Our data suggest more engagement of neural networks of the right hemisphere are involved in Zapotec language discrimination. Copyright © 2015 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

  5. Eclipsing binaries in open clusters

    DEFF Research Database (Denmark)

    Southworth, John; Clausen, J.V.

    2006-01-01

    Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August......Stars: fundamental parameters - Stars : binaries : eclipsing - Stars: Binaries: spectroscopic - Open clusters and ass. : general Udgivelsesdato: 5 August...

  6. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. II. P-TYPE BINARIES

    International Nuclear Information System (INIS)

    Haghighipour, Nader; Kaltenegger, Lisa

    2013-01-01

    We have developed a comprehensive methodology for calculating the circumbinary habitable zone (HZ) in planet-hosting P-type binary star systems. We present a general formalism for determining the contribution of each star of the binary to the total flux received at the top of the atmosphere of an Earth-like planet and use the Sun's HZ to calculate the inner and outer boundaries of the HZ around a binary star system. We apply our calculations to the Kepler's currently known circumbinary planetary systems and show the combined stellar flux that determines the boundaries of their HZs. We also show that the HZ in P-type systems is dynamic and, depending on the luminosity of the binary stars, their spectral types, and the binary eccentricity, its boundaries vary as the stars of the binary undergo their orbital motion. We present the details of our calculations and discuss the implications of the results

  7. CALCULATING THE HABITABLE ZONE OF BINARY STAR SYSTEMS. II. P-TYPE BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Haghighipour, Nader [Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii-Manoa, Honolulu, HI 96822 (United States); Kaltenegger, Lisa [MPIA, Koenigstuhl 17, Heidelberg, D-69117 (Germany)

    2013-11-10

    We have developed a comprehensive methodology for calculating the circumbinary habitable zone (HZ) in planet-hosting P-type binary star systems. We present a general formalism for determining the contribution of each star of the binary to the total flux received at the top of the atmosphere of an Earth-like planet and use the Sun's HZ to calculate the inner and outer boundaries of the HZ around a binary star system. We apply our calculations to the Kepler's currently known circumbinary planetary systems and show the combined stellar flux that determines the boundaries of their HZs. We also show that the HZ in P-type systems is dynamic and, depending on the luminosity of the binary stars, their spectral types, and the binary eccentricity, its boundaries vary as the stars of the binary undergo their orbital motion. We present the details of our calculations and discuss the implications of the results.

  8. The UNICAMP theta-pinch for spectroscopic study of plasma radiations

    International Nuclear Information System (INIS)

    Trigueiros, A.G.; Luna, F.R.T.; Holanda Cavalcanti, G. de; Mania, A.J.

    1993-01-01

    The emission spectrum of six times ionized xenon (Xe VII), has been observed in the vacuum ultraviolet (VUV) using a theta-pinch discharge. The spectrum was recorded with a 2-meter normal incidence spectrograph in the 300-2000 A region. Preliminary results allow the identification of transitions in the n=5 complex. Ten of these transitions were identified. The identifications are supported by relativistic Hartree-Fock calculations. (author)

  9. Distinguishing stimulus and response codes in theta oscillations in prefrontal areas during inhibitory control of automated responses.

    Science.gov (United States)

    Mückschel, Moritz; Dippel, Gabriel; Beste, Christian

    2017-11-01

    Response inhibition mechanisms are mediated via cortical and subcortical networks. At the cortical level, the superior frontal gyrus, including the supplementary motor area (SMA) and inferior frontal areas, is important. There is an ongoing debate about the functional roles of these structures during response inhibition as it is unclear whether these structures process different codes or contents of information during response inhibition. In the current study, we examined this question with a focus on theta frequency oscillations during response inhibition processes. We used a standard Go/Nogo task in a sample of human participants and combined different EEG signal decomposition methods with EEG beamforming approaches. The results suggest that stimulus coding during inhibitory control is attained by oscillations in the upper theta frequency band (∼7 Hz). In contrast, response selection codes during inhibitory control appear to be attained by the lower theta frequency band (∼4 Hz). Importantly, these different codes seem to be processed in distinct functional neuroanatomical structures. Although the SMA may process stimulus codes and response selection codes, the inferior frontal cortex may selectively process response selection codes during inhibitory control. Taken together, the results suggest that different entities within the functional neuroanatomical network associated with response inhibition mechanisms process different kinds of codes during inhibitory control. These codes seem to be reflected by different oscillations within the theta frequency band. Hum Brain Mapp 38:5681-5690, 2017. © 2017 Wiley-Liss, Inc. © 2017 Wiley Periodicals, Inc.

  10. Microbial hydroxylation and glycosidation of oleanolic acid by Circinella muscae and their anti-inflammatory activities.

    Science.gov (United States)

    Yan, Sensen; Lin, Haijun; Huang, Huilian; Yang, Min; Xu, Bohui; Chen, Guangtong

    2018-05-29

    Biotransformation of oleanolic acid (OA) by Circinella muscae AS 3.2695 was investigated. Nine hydroxylated and glycosylated metabolites (1-9) were obtained. Their structures were elucidated as 3β,7β-dihydroxyolean-12-en-28-oic acid (1), 3β,7β,21β-trihydroxyolean-12-en-28-oic acid (2), 3β,7α,21β-trihydroxyolean-12-en- 28-oic acid (3), 3β,7β,15α-trihydroxyolean-12-en-28-oic acid (4), 7β,15α-dihydroxy- 3-oxo-olean-12-en-28-oic acid (5), 7β-hydroxy-3-oxo-olean-12-en-28-oic acid (6), oleanolic acid-28-O-β-D-glucopyranosyl ester (7), 3β,21β-dihydroxyolean-12-en-28- oic acid-28-O-β-D-glucopyranosyl ester (8), and 3β,7β,15α-trihydroxyolean-12-en- 28-oic acid-28-O-β-D-glucopyranosyl ester (9) by spectroscopic analysis. Among them, compounds 4 and 9 were new compounds. In addition, anti-inflammatory activities were assayed and evaluated for the isolated metabolites. Most of the metabolites exhibited significant inhibitory activities on lipopolysaccharides-induced NO production in RAW 264.7 cells.

  11. Close binary stars

    International Nuclear Information System (INIS)

    Larsson-Leander, G.

    1979-01-01

    Studies of close binary stars are being persued more vigorously than ever, with about 3000 research papers and notes pertaining to the field being published during the triennium 1976-1978. Many major advances and spectacular discoveries were made, mostly due to increased observational efficiency and precision, especially in the X-ray, radio, and ultraviolet domains. Progress reports are presented in the following areas: observational techniques, methods of analyzing light curves, observational data, physical data, structure and models of close binaries, statistical investigations, and origin and evolution of close binaries. Reports from the Coordinates Programs Committee, the Committee for Extra-Terrestrial Observations and the Working Group on RS CVn binaries are included. (Auth./C.F.)

  12. Network models provide insights into how oriens–lacunosum-moleculare and bistratified cell interactions influence the power of local hippocampal CA1 theta oscillations

    Directory of Open Access Journals (Sweden)

    Katie A Ferguson

    2015-08-01

    Full Text Available Hippocampal theta is a 4-12 Hz rhythm associated with episodic memory, and although it has been studied extensively, the cellular mechanisms underlying its generation are unclear. The complex interactions between different interneuron types, such as those between oriens--lacunosum-moleculare (OLM interneurons and bistratified cells (BiCs, make their contribution to network rhythms difficult to determine experimentally. We created network models that are tied to experimental work at both cellular and network levels to explore how these interneuron interactions affect the power of local oscillations. Our cellular models were constrained with properties from patch clamp recordings in the CA1 region of an intact hippocampus preparation in vitro. Our network models are composed of three different types of interneurons: parvalbumin-positive (PV+ basket and axo-axonic cells (BC/AACs, PV+ BiCs, and somatostatin-positive OLM cells. Also included is a spatially extended pyramidal cell model to allow for a simplified local field potential representation, as well as experimentally-constrained, theta frequency synaptic inputs to the interneurons. The network size, connectivity, and synaptic properties were constrained with experimental data. To determine how the interactions between OLM cells and BiCs could affect local theta power, we explored a number of OLM-BiC connections and connection strengths.We found that our models operate in regimes in which OLM cells minimally or strongly affected the power of network theta oscillations due to balances that, respectively, allow compensatory effects or not. Inactivation of OLM cells could result in no change or even an increase in theta power. We predict that the dis-inhibitory effect of OLM cells to BiCs to pyramidal cell interactions plays a critical role in the power of network theta oscillations. Our network models reveal a dynamic interplay between different classes of interneurons in influencing local theta

  13. Medial septal GABAergic projection neurons promote object exploration behavior and type 2 theta rhythm

    Science.gov (United States)

    Gangadharan, Gireesh; Shin, Jonghan; Kim, Seong-Wook; Kim, Angela; Paydar, Afshin; Kim, Duk-Soo; Miyazaki, Taisuke; Watanabe, Masahiko; Yanagawa, Yuchio; Kim, Jinhyun; Kim, Yeon-Soo; Kim, Daesoo; Shin, Hee-Sup

    2016-01-01

    Exploratory drive is one of the most fundamental emotions, of all organisms, that are evoked by novelty stimulation. Exploratory behavior plays a fundamental role in motivation, learning, and well-being of organisms. Diverse exploratory behaviors have been described, although their heterogeneity is not certain because of the lack of solid experimental evidence for their distinction. Here we present results demonstrating that different neural mechanisms underlie different exploratory behaviors. Localized Cav3.1 knockdown in the medial septum (MS) selectively enhanced object exploration, whereas the null mutant (KO) mice showed enhanced-object exploration as well as open-field exploration. In MS knockdown mice, only type 2 hippocampal theta rhythm was enhanced, whereas both type 1 and type 2 theta rhythm were enhanced in KO mice. This selective effect was accompanied by markedly increased excitability of septo-hippocampal GABAergic projection neurons in the MS lacking T-type Ca2+ channels. Furthermore, optogenetic activation of the septo-hippocampal GABAergic pathway in WT mice also selectively enhanced object exploration behavior and type 2 theta rhythm, whereas inhibition of the same pathway decreased the behavior and the rhythm. These findings define object exploration distinguished from open-field exploration and reveal a critical role of T-type Ca2+ channels in the medial septal GABAergic projection neurons in this behavior. PMID:27208094

  14. Massive Black Hole Binary Evolution

    Directory of Open Access Journals (Sweden)

    Merritt David

    2005-11-01

    Full Text Available Coalescence of binary supermassive black holes (SBHs would constitute the strongest sources of gravitational waves to be observed by LISA. While the formation of binary SBHs during galaxy mergers is almost inevitable, coalescence requires that the separation between binary components first drop by a few orders of magnitude, due presumably to interaction of the binary with stars and gas in a galactic nucleus. This article reviews the observational evidence for binary SBHs and discusses how they would evolve. No completely convincing case of a bound, binary SBH has yet been found, although a handful of systems (e.g. interacting galaxies; remnants of galaxy mergers are now believed to contain two SBHs at projected separations of <~ 1kpc. N-body studies of binary evolution in gas-free galaxies have reached large enough particle numbers to reproduce the slow, “diffusive” refilling of the binary’s loss cone that is believed to characterize binary evolution in real galactic nuclei. While some of the results of these simulations - e.g. the binary hardening rate and eccentricity evolution - are strongly N-dependent, others - e.g. the “damage” inflicted by the binary on the nucleus - are not. Luminous early-type galaxies often exhibit depleted cores with masses of ~ 1-2 times the mass of their nuclear SBHs, consistent with the predictions of the binary model. Studies of the interaction of massive binaries with gas are still in their infancy, although much progress is expected in the near future. Binary coalescence has a large influence on the spins of SBHs, even for mass ratios as extreme as 10:1, and evidence of spin-flips may have been observed.

  15. Effiacy of citronella and eucalyptus oils against Musca domestica, Cimex lectularius and Pediculus humanus

    Directory of Open Access Journals (Sweden)

    Jehangir Khan

    2017-11-01

    Full Text Available Objective: To assess potential impacts of two indigenous plant oils: the citronella (Cymbopogon nardus and eucalyptus (Eucalyptus globulus for their insecticidal effect against Musca domestica (house fly, Cimex lectularius (bed bug and Pediculus humanus (louse. Methods: The oils of these two medicinal plants were applied separately at various concentrations (1, 2 and 3 mL/cup in cups lined with filter paper containing the target insects. Mortality was evaluated after fixed intervals (6, 12 and 24 h subsequent to the release of adult insects. Results: Results showed that both oils exhibited concentration and time dependent mortality against the tested insects. Data pertaining to present investigation clearly showed that percentage mortality owing to these botanicals against these medical pests was significantly high (98.33% at the rate of 3 mL for 24 h of exposure, followed by 2 and 1 mL concentrations with 12 and 6 h of exposure times. Conclusions: The results suggest that these plant oils possess good insecticidal properties against house fly, bed bug, and louse, and are safe to humans. Furthermore, the molecular (biochemical based study of these botanicals against diverse species of pests will be of much significance to control these pest insects.

  16. Pertumbuhan dan perkembangan larva Musca domestica Linnaeus (Diptera: Muscidae dalam beberapa jenis kotoran ternak

    Directory of Open Access Journals (Sweden)

    Ramadhani Eka Putra

    2015-09-01

    Full Text Available House fly (Musca domestica is an important urban insect that can transmit various infectious diseases. This insect usually utilized organic wastes as nutrition source for their larvae. One of the main sources of organic wastes is livestock manure produced by animal farming located near human dwelling area. Thus, appropriate house fly population control program at animal farm is needed,based on information on the house fly’s life history. The research is focused on the development of house fly larvae reared with different livestock manures, such as cow, chicken, and horse. As comparison, rice bran were used as control. Results showed that larvae reared with horse manure has the shortest development time (5 days, with lowest larval survival rate (30%, pupal weight (6.8 ± 0.141 g, and weight of female imago (4.9 ± 0.14 g. This finding indicates the lowest nutrition value of horse manure for house flies larvae. Further research is needed to find the effect of manure to variables that directly influence population growth, such as fecundity of female flies and egg survivorship. These additional information on life history will help the design of appropriate house fly population management program for animal farm.

  17. Histamine Enhances Theta-Coupled Spiking and Gamma Oscillations in the Medial Entorhinal Cortex Consistent With Successful Spatial Recognition.

    Science.gov (United States)

    Chen, Quanhui; Luo, Fenlan; Yue, Faguo; Xia, Jianxia; Xiao, Qin; Liao, Xiang; Jiang, Jun; Zhang, Jun; Hu, Bo; Gao, Dong; He, Chao; Hu, Zhian

    2017-06-07

    Encoding of spatial information in the superficial layers of the medial entorhinal cortex (sMEC) involves theta-modulated spiking and gamma oscillations, as well as spatially tuned grid cells and border cells. Little is known about the role of the arousal-promoting histaminergic system in the modification of information encoded in the sMEC in vivo, and how such histamine-regulated information correlates with behavioral functions. Here, we show that histamine upregulates the neural excitability of a significant proportion of neurons (16.32%, 39.18%, and 52.94% at 30 μM, 300 μM, and 3 mM, respectively) and increases local theta (4-12 Hz) and gamma power (low: 25-48 Hz; high: 60-120 Hz) in the sMEC, through activation of histamine receptor types 1 and 3. During spatial exploration, the strength of theta-modulated firing of putative principal neurons and high gamma oscillations is enhanced about 2-fold by histamine. The histamine-mediated increase of theta phase-locking of spikes and high gamma power is consistent with successful spatial recognition. These results, for the first time, reveal possible mechanisms involving the arousal-promoting histaminergic system in the modulation of spatial cognition. Published by Oxford University Press 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  18. Computer simulation of plasma behavior in open-ended linear theta machines. Scientific report 81-5

    International Nuclear Information System (INIS)

    Stover, E.K.

    1981-04-01

    Zero-dimensional and one-dimensional fluid plasma computer models have been developed to study the behavior of linear theta pinch plasmas. Computer simulation results generated from these codes are compared with data obtained from two theta pinch experiments so that significant machine plasma behavior can be identified. The experiments examined are a collisional experiment, T/sub i/ approx. 50 eV, n/sub e/ approx. 10 17 cm -3 , where the plasma mean-free-path was significantly less than the plasma column length, and a hot ion species experiment, T/sub i/ approx. 3 keV, n/sub e/ approx. 10 16 cm -3 , where the ion mean-free-path was on the order of the plasma column length

  19. Learning curves of theta/beta neurofeedback in children with ADHD.

    Science.gov (United States)

    Janssen, Tieme W P; Bink, Marleen; Weeda, Wouter D; Geladé, Katleen; van Mourik, Rosa; Maras, Athanasios; Oosterlaan, Jaap

    2017-05-01

    Neurofeedback is widely applied as non-pharmacological intervention aimed at reducing symptoms of ADHD, even though efficacy has not been unequivocally established. Neuronal changes during the neurofeedback intervention that resemble learning can provide crucial evidence for the feasibility and specificity of this intervention. A total of 38 children (aged between 7 and 13 years) with a DSM-IV-TR diagnosis of ADHD, completed on average 29 sessions of theta (4-8 Hz)/beta (13-20 Hz) neurofeedback training. Dependent variables included training-related measures as well as theta and beta power during baseline and training runs for each session. Learning effects were analyzed both within and between sessions. To further specify findings, individual learning curves were explored and correlated with behavioral changes in ADHD symptoms. Over the course of the training, there was a linear increase in participants' mean training level, highest obtained training level and the number of earned credits (range b = 0.059, -0.750, p neurofeedback, although a lack of behavioral correlates may indicate insufficient transfer to daily functioning, or to confounding reinforcement of electromyographic activity. This trial is registered at the US National Institutes of Health (ClinicalTrials.gov, ref. no: NCT01363544); https://clinicaltrials.gov/show/NCT01363544 .

  20. EEG theta and gamma responses to semantic violations in online sentence processing

    NARCIS (Netherlands)

    Hald, L.A.; Bastiaansen, M.C.M.; Hagoort, P.

    2006-01-01

    We explore the nature of the oscillatory dynamics in the EEG of subjects reading sentences that contain a semantic violation. More specifically, we examine whether increases in theta (≈3–7 Hz) and gamma (around 40 Hz) band power occur in response to sentences that were either semantically correct or

  1. Musca domestica Salivary Gland Hypertrophy Virus, a Globally Distributed Insect Virus That Infects and Sterilizes Female Houseflies

    DEFF Research Database (Denmark)

    Prompiboon, Pannipa; Lietze, Verena-Ulrike; Denton, John S S

    2010-01-01

    The housefly, Musca domestica, is a cosmopolitan pest of livestock and poultry and is of economic, veterinary, and public health importance. Populations of M. domestica are naturally infected with M. domestica salivary gland hypertrophy virus (MdSGHV), a nonoccluded double-stranded DNA virus...... that inhibits egg production in infected females and is characterized by salivary gland hypertrophy (SGH) symptoms. MdSGHV has been detected in housefly samples from North America, Europe, Asia, the Caribbean, and the southwestern Pacific. In this study, houseflies were collected from various locations......, and the polymorphism detected was correlated with geographic source. The virulence of the geographic MdSGHV isolates was evaluated by per os treatment of newly emerged and 24-h-old houseflies with homogenates of infected salivary glands. In all cases, 24-h-old flies displayed a resistance to oral infection...

  2. Quantitative EEG in Children and Adults With Attention Deficit Hyperactivity Disorder: Comparison of Absolute and Relative Power Spectra and Theta/Beta Ratio.

    Science.gov (United States)

    Markovska-Simoska, Silvana; Pop-Jordanova, Nada

    2017-01-01

    In recent decades, resting state electroencephalographic (EEG) measures have been widely used to document underlying neurophysiological dysfunction in attention deficit hyperactivity disorder (ADHD). Although most EEG studies focus on children, there is a growing interest in adults with ADHD too. The aim of this study was to objectively assess and compare the absolute and relative EEG power as well as the theta/beta ratio in children and adults with ADHD. The evaluated sample comprised 30 male children and 30 male adults with ADHD diagnosed according to DSM-IV criteria. They were compared with 30 boys and 30 male adults matched by age. The mean age (±SD) of the children's group was 9 (±2.44) years and the adult group 35.8 (±8.65) years. EEG was recorded during an eyes-open condition. Spectral analysis of absolute (μV 2 ) and relative power (%) was carried out for 4 frequency bands: delta (2-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), and beta (13-21 Hz). The findings obtained for ADHD children are increased absolute power of slow waves (theta and delta), whereas adults exhibited no differences compared with normal subjects. For the relative power spectra there were no differences between the ADHD and control groups. Across groups, the children showed greater relative power than the adults in the delta and theta bands, but for the higher frequency bands (alpha and beta) the adults showed more relative power than children. Only ADHD children showed greater theta/beta ratio compared to the normal group. Classification analysis showed that ADHD children could be differentiated from the control group by the absolute theta values and theta/beta ratio at Cz, but this was not the case with ADHD adults. The question that should be further explored is if these differences are mainly due to maturation processes or if there is a core difference in cortical arousal between ADHD children and adults. © EEG and Clinical Neuroscience Society (ECNS) 2016.

  3. Search for the Theta+ pentaquark in the reactions gammap-->[overline K]0K+n and gammap-->[overline K]0K0p

    Energy Technology Data Exchange (ETDEWEB)

    Raffaella De Vita; Marco Battaglieri; V. Kubarovsky; Nathan Baltzell; Matthew Bellis; John Goett; Lei Guo; Gordon Mutchler; Paul Stoler; Maurizio Ungaro; Dennis Weygand; Moscov Amaryan; Pawel Ambrozewicz; Marco Anghinolfi; Gegham Asryan; Harutyun AVAKIAN; Harutyun Avakian; Hovhannes Baghdasaryan; Nathan Baillie; Jacques Ball; Vitaly Baturin; Ivan Bedlinski; Ivan Bedlinskiy; Nawal Benmouna; Barry Berman; Angela Biselli; Sergey Boyarinov; Sylvain Bouchigny; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; Sharon Careccia; Daniel Carman; Shifeng Chen; Eric Clinton; Philip Cole; Patrick Collins; Philip Coltharp; Donald Crabb; Hall Crannell; Volker Crede; John Cummings; D. Dale; Raffaella De Vita; Enzo De Sanctis; Pavel Degtiarenko; Alexandre Deur; Kahanawita Dharmawardane; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; Lamiaa Elfassi; Latifa Elouadrhiri; Paul Eugenio; Gleb Fedotov; Herbert Funsten; Marianna Gabrielyan; Liping Gan; Michel Garcon; Ashot Gasparian; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; Oleksandr Glamazdin; John Goetz; Evgueni Golovatch; Atilla Gonenc; Christopher Gordon; Ralf Gothe; Keith Griffioen; Michel Guidal; Nevzat Guler; Harutyun Gyurjyan; Cynthia Hadjidakis; Kawtar Hafidi; Hayk Hakobyan; Rafael Hakobyan; John Hardie; F. Hersman; Kenneth Hicks; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; D. Jenkins; Hyon-Suk Jo; Kyungseon Joo; Henry Juengst; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Andreas Klein; Franz Klein; Alexei Klimenko; Mikhail Kossov; Laird Kramer; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Jeff Lachniet; Jean Laget; Jorn Langheinrich; Dave Lawrence; Tsung-shung Lee; Ji Li; K. Livingston; Haiyun Lu; Marion MacCormick; Nikolai Markov; Bryan McKinnon; Bernhard Mecking; Joseph Melone; Mac Mestayer; Curtis Meyer; Tsutomu Mibe; Konstantin Mikhaylov; Ralph Minehart; Marco Mirazita; R. Miskimen; Vasiliy Mochalov; Viktor Mokeev; Ludyvine Morand; Steven Morrow; Maryam Moteabbed; Pawel Nadel-Turonski; Itaru Nakagawa; Rakhsha Nasseripour; Silvia Niccolai; Gabriel Niculescu; Maria-Ioana Niculescu; Bogdan Niczyporuk; Megh Niroula; Rustam Niyazov; Mina Nozar; Mikhail Osipenko; Alexander Ostrovidov; Kijun Park; Evgueni Pasyuk; Craig Paterson; Joshua Pierce; Nikolay Pivnyuk; Dinko Pocanic; Oleg Pogorelko; Sergey Pozdnyakov; John Price; Yelena Prok; Dan Protopopescu; Brian Raue; Gregory Riccardi; Giovanni Ricco; Marco Ripani; Barry Ritchie; Federico Ronchetti; Guenther Rosner; Patrizia Rossi; Franck Sabatie; Carlos Salgado; Joseph Santoro; Vladimir Sapunenko; Reinhard Schumacher; Vladimir Serov; Youri Sharabian; Nikolay Shvedunov; Elton Smith; Lee Smith; Daniel Sober; Aleksey Stavinskiy; Samuel Stepanyan; Stepan Stepanyan; Burnham Stokes; Igor Strakovski; Steffen Strauch; Mauro Taiuti; David Tedeschi; Aram Teymurazyan; Ulrike Thoma; Avtandil Tkabladze; Svyatoslav Tkachenko; Luminita Todor; Clarisse Tur; Michael Vineyard; Alexander Vlassov; Daniel Watts; Lawrence Weinstein; M. Williams; Elliott Wolin; Michael Wood; Amrit Yegneswaran; Lorenzo Zana; Jixie Zhang; Bo Zhao; Zhiwen Zhao

    2006-11-16

    The exclusive reactions {gamma}p {yields} {bar K}{sup 0} K{sup +} n and {gamma}p {yields} {bar K}{sup 0} K{sup 0} p have been studied in the photon energy range 1.6--3.8 GeV, searching for evidence of the exotic baryon {Theta}{sup +}(1540) in the decays {Theta}{sup +} {yields} nK{sup +} and {Theta}{sup +} {yields} pK{sup 0}. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The integrated luminosity was about 70 pb{sup -1}. The reactions have been isolated by detecting the K{sup +} and proton directly, the neutral kaon via its decay to K{sub S} {yields} {pi}{sup +}{pi}{sup -} and the neutron or neutral kaon via the missing mass technique. The mass and width of known hyperons such as {Sigma}{sup +}, {Sigma}{sup -} and {Lambda}(1116) were used as a check of the mass determination accuracy and experimental resolution. Approximately 100,000 {Lambda}*(1520)'s and 150,000 {phi}'s were observed in the {bar K}{sup 0} K{sup +} n and {bar K}{sup 0} K{sup 0} p final state respectively. No evidence for the {Theta}{sup +} pentaquark was found in the nK{sup +} or pK{sub S} invariant mass spectra. Upper limits were set on the production cross section of the reaction {gamma}p {yields} {Theta}{sup +} {bar K}{sup 0} as functions of center-of-mass angle, nK{sup +} and pK{sub S} masses. Combining the results of the two reactions, the 95% C.L. upper limit on the total cross section for a resonance peaked at 1540 MeV was found to be 0.7 nb. Within most of the available theoretical models, this corresponds to an upper limit on the {Theta}{sup +} width, {Gamma}{sub {Theta}{sup +}}, ranging between 0.01 and 7 MeV.

  4. Plasma experiments on staged theta pinch, implosion heating experiment and Scyllac feedback-sector experiment

    International Nuclear Information System (INIS)

    Bartsch, R.R.; Buchenauer, C.J.; Cantrell, E.L.

    1977-01-01

    Results of the Los Alamos theta-pinch program in three areas of investigation are summarized: 1) In the Staged Theta Pinch, results are reported on the effects of magnetic field amplitude and time history of plasma formation. 2) In the Implosion Heating Experiment, density, internal-magnetic field and neutron measurements yield a consistent picture of the implosion which agrees with kinetic computations and with a simple dynamic model of the ions and magnetic piston. 3) In the Scyllac Feedback-Sector Experiment, the l=1, 0 equilibrium plasma parameters have been adjusted to accommodate the feedback stabilization system. With a uniform toroidal discharge tube the m=1 instability is feedback-stabilized in the vertical direction, and confinement in the toroidal direction is extended by feedback control. Results with a helical discharge tube are also reported. (author)

  5. Superconformal algebras and mock theta functions

    International Nuclear Information System (INIS)

    Eguchi, Tohru; Hikami, Kazuhiro

    2009-01-01

    It is known that characters of BPS representations of extended superconformal algebras do not have good modular properties due to extra singular vectors coming from the BPS condition. In order to improve their modular properties we apply the method of Zwegers which has recently been developed to analyze modular properties of mock theta functions. We consider the case of the N=4 superconformal algebra at general levels and obtain the decomposition of characters of BPS representations into a sum of simple Jacobi forms and an infinite series of non-BPS representations. We apply our method to study elliptic genera of hyper-Kaehler manifolds in higher dimensions. In particular, we determine the elliptic genera in the case of complex four dimensions of the Hilbert scheme of points on K3 surfaces K [2] and complex tori A [[3

  6. Superconformal algebras and mock theta functions

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, Tohru [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Hikami, Kazuhiro [Department of Mathematics, Naruto University of Education, Tokushima 772-8502 (Japan)], E-mail: eguchi@yukawa.kyoto-u.ac.jp, E-mail: hikami@naruto-u.ac.jp

    2009-07-31

    It is known that characters of BPS representations of extended superconformal algebras do not have good modular properties due to extra singular vectors coming from the BPS condition. In order to improve their modular properties we apply the method of Zwegers which has recently been developed to analyze modular properties of mock theta functions. We consider the case of the N=4 superconformal algebra at general levels and obtain the decomposition of characters of BPS representations into a sum of simple Jacobi forms and an infinite series of non-BPS representations. We apply our method to study elliptic genera of hyper-Kaehler manifolds in higher dimensions. In particular, we determine the elliptic genera in the case of complex four dimensions of the Hilbert scheme of points on K3 surfaces K{sup [2]} and complex tori A{sup [[3

  7. Velocity-space particle loss in field-reversed theta pinches

    International Nuclear Information System (INIS)

    Hsiao, M.Y.

    1983-01-01

    A field-reversed theta pinch (FRTP) is a compact device for magnetic fusion. It has attracted much attention in recent years since encouraging experimental results have been obtained. However, the definite causes for the observed particle loss rate and plasma rotation are not well known. In this work, we study the velocity-space particle loss (VSPL), i.e., particle loss due to the existence of a loss region in velocity space, in FRTP's in order to have a better understanding about the characteristics of this device

  8. Resting-state theta-band connectivity and verbal memory in schizophrenia and in the high-risk state.

    Science.gov (United States)

    Andreou, Christina; Leicht, Gregor; Nolte, Guido; Polomac, Nenad; Moritz, Steffen; Karow, Anne; Hanganu-Opatz, Ileana L; Engel, Andreas K; Mulert, Christoph

    2015-02-01

    Disturbed functional connectivity is assumed to underlie neurocognitive deficits in patients with schizophrenia. As neurocognitive deficits are already present in the high-risk state, identification of the neural networks involved in this core feature of schizophrenia is essential to our understanding of the disorder. Resting-state studies enable such investigations, while at the same time avoiding the known confounder of impaired task performance in patients. The aim of the present study was to investigate EEG resting-state connectivity in high-risk individuals (HR) compared to first episode patients with schizophrenia (SZ) and to healthy controls (HC), and its association with cognitive deficits. 64-channel resting-state EEG recordings (eyes closed) were obtained for 28 HR, 19 stable SZ, and 23 HC, matched for age, education, and parental education. The imaginary coherence-based multivariate interaction measure (MIM) was used as a measure of connectivity across 80 cortical regions and six frequency bands. Mean connectivity at each region was compared across groups using the non-parametric randomization approach. Additionally, the network-based statistic was applied to identify affected networks in patients. SZ displayed increased theta-band resting-state MIM connectivity across midline, sensorimotor, orbitofrontal regions and the left temporoparietal junction. HR displayed intermediate theta-band connectivity patterns that did not differ from either SZ or HC. Mean theta-band connectivity within the above network partially mediated verbal memory deficits in SZ and HR. Aberrant theta-band connectivity may represent a trait characteristic of schizophrenia associated with neurocognitive deficits. As such, it might constitute a promising target for novel treatment applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Theta oscillation and neuronal activity in rat hippocampus areinvolved in temporal discrimination of time in seconds

    Directory of Open Access Journals (Sweden)

    Tomoaki eNakazono

    2015-06-01

    Full Text Available The discovery of time cells revealed that the rodent hippocampus has information of time.Previous studies have suggested that a role of hippocampal time cells is to integratetemporally segregated events into a sequence using working memory with time perception.However, it is unclear that hippocampal cells contribute to time perception itself becausemost previous studies employed delayed matching-to-sample tasks that did not evaluatetime perception separately from working memory processes. Here, we investigated thefunction of the rat hippocampus in time perception using a temporal discrimination task. Inthe task, rats had to discriminate between durations of 1 and 3 sec to get a reward, andmaintaining task-related information as working memory was not required. We found thatsome hippocampal neurons showed firing rate modulation similar to that of time cells.Moreover, theta oscillation of local field potentials (LFPs showed a transient enhancementof power during time discrimination periods. However, there were little relationshipsbetween the neuronal activities and theta oscillations. These results suggest that both theindividual neuronal activities and theta oscillations of LFPs in the hippocampus have a possibility to be engaged in seconds order time perception; however, they participate in different ways.

  10. Search for the Theta+ pentaquark in the gamma d -> Lambda n K+ reaction measured with CLAS

    Energy Technology Data Exchange (ETDEWEB)

    Silvia Niccolai; Marco Mirazita; Patrizia Rossi; Nathan Baltzell; Daniel Carman; Kenneth Hicks; Bryan McKinnon; Tsutomu Mibe; Stepan Stepanyan; David Tedeschi; Gary Adams; Pawel Ambrozewicz; Sergio Pereira; Marco Anghinolfi; Gegham Asryan; Harutyun AVAKIAN; H. Bagdasaryan; Nathan Baillie; Jacques Ball; V. Batourine; Marco Battaglieri; Ivan Bedlinski; Ivan Bedlinskiy; Ivan Bedlinski; Ivan Bedlinskiy; Mehmet Bektasoglu; Matthew Bellis; Nawal Benmouna; Barry Berman; Angela Biselli; Sergey Boyarinov; Sylvain Bouchigny; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; S.L. Careccia; Bryan Carnahan; Shifeng Chen; Philip Cole; Patrick Collins; Philip Coltharp; Donald Crabb; Hall Crannell; V. Crede; John Cummings; Natalya Dashyan; Pavel Degtiarenko; Rita De Masi; Airton Deppman; Enzo De Sanctis; Alexandre Deur; Raffaella De Vita; Kahanawita Dharmawardane; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; L. El Fassi; Latifa Elouadrhiri; Paul Eugenio; Gleb Fedotov; Gerald Feldman; Herbert Funsten; Michel Garcon; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; John Goetz; Atilla Gonenc; Christopher Gordon; Ralf Gothe; Keith Griffioen; Michel Guidal; Nevzat Guler; Lei Guo; Vardan Gyurjyan; Cynthia Hadjidakis; Kawtar Hafidi; Hayk Hakobyan; Rafael Hakobyan; John Hardie; F. Hersman; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; David Jenkins; Hyon-Suk Jo; Kyungseon Joo; Henry Juengst; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Andreas Klein; Franz Klein; Alexei Klimenko; Mikhail Kossov; Laird Kramer; V. Kubarovsky; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Jeff Lachniet; Jorn Langheinrich; David Lawrence; Tsung-shung Lee; Kenneth Livingston; H. Lu; Marion MacCormick; Nikolai Markov; Bernhard Mecking; Jonathan Mellor; Joseph Melone; Mac Mestayer; Curtis Meyer; Konstantin Mikhaylov; Ralph Minehart; Rory Miskimen; Viktor Mokeev; Ludyvine Morand; Steven Morrow; Maryam Moteabbed; Gordon Mutchler; Pawel Nadel-Turonski; James Napolitano; Rakhsha Nasseripour; Gabriel Niculescu; Maria-Ioana Niculescu; Bogdan Niczyporuk; Megh Niroula; Rustam Niyazov; Mina Nozar; Jorge De Olivei Echeimberg; Mikhail Osipenko; Alexander Ostrovidov; K. Park; Evgueni Pasyuk; Craig Paterson; Joshua Pierce; Nikolay Pivnyuk; Dinko Pocanic; Oleg Pogorelko; Sergey Pozdnyakov; Barry Preedom; John Price; Yelena Prok; Dan Protopopescu; Brian Raue; Gregory Riccardi; Giovanni Ricco; Marco Ripani; Barry Ritchie; Federico Ronchetti; Guenther Rosner; Franck Sabatie; Carlos Salgado; Joseph Santoro; Vladimir Sapunenko; Reinhard Schumacher; Vladimir Serov; Youri Sharabian; Nikolay Shvedunov; Elton Smith; Lee Smith; Daniel Sober; Aleksey Stavinskiy; Stepan Stepanyan; Burnham Stokes; Paul Stoler; Igor Strakovski; Steffen Strauch; Mauro Taiuti; Ulrike Thoma; Avtandil Tkabladze; Svyatoslav Tkachenko; Luminita Todor; Clarisse Tur; Maurizio Ungaro; Michael Vineyard; Alexander Vlassov; Daniel Watts; Lawrence Weinstein; Dennis Weygand; M. Williams; Elliott Wolin; Michael Wood; Amrit Yegneswaran; Lorenzo Zana; Jixie Zhang; Bo Zhao; Zhiwen Zhao

    2006-04-26

    For the first time, the reaction gamma d -> Lambda n K+ has been analyzed in order to search for the exotic pentaquark baryon Theta+(1540). The data were taken at Jefferson Lab, using the Hall-B tagged-photon beam of energy between 0.8 and 3.6 GeV and the CEBAF Large Acceptance Spectrometer (CLAS). No statistically significant structures were observed in the nK+ invariant mass distribution. The upper limit on the gamma d -> Lambda Theta+ integrated cross section has been calculated and found to be between 5 and 25 nb, depending on the production model assumed. The upper limit on the differential cross section is also reported.

  11. Search for the Theta+ pentaquark in the gamma d -> Lambda n K+ reaction measured with CLAS

    International Nuclear Information System (INIS)

    Silvia Niccolai; Marco Mirazita; Patrizia Rossi; Nathan Baltzell; Daniel Carman; Kenneth Hicks; Bryan McKinnon; Tsutomu Mibe; Stepan Stepanyan; David Tedeschi; Gary Adams; Pawel Ambrozewicz; Sergio Pereira; Marco Anghinolfi; Gegham Asryan; Harutyun AVAKIAN; H. Bagdasaryan; Nathan Baillie; Jacques Ball; V. Batourine; Marco Battaglieri; Ivan Bedlinski; Ivan Bedlinskiy; Ivan Bedlinski; Ivan Bedlinskiy; Mehmet Bektasoglu; Matthew Bellis; Nawal Benmouna; Barry Berman; Angela Biselli; Sergey Boyarinov; Sylvain Bouchigny; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; S.L. Careccia; Bryan Carnahan; Shifeng Chen; Philip Cole; Patrick Collins; Philip Coltharp; Donald Crabb; Hall Crannell; V. Crede; John Cummings; Natalya Dashyan; Pavel Degtiarenko; Rita De Masi; Airton Deppman; Enzo De Sanctis; Alexandre Deur; Raffaella De Vita; Kahanawita Dharmawardane; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; L. El Fassi; Latifa Elouadrhiri; Paul Eugenio; Gleb Fedotov; Gerald Feldman; Herbert Funsten; Michel Garcon; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; John Goetz; Atilla Gonenc; Christopher Gordon; Ralf Gothe; Keith Griffioen; Michel Guidal; Nevzat Guler; Lei Guo; Vardan Gyurjyan; Cynthia Hadjidakis; Kawtar Hafidi; Hayk Hakobyan; Rafael Hakobyan; John Hardie; F. Hersman; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; David Jenkins; Hyon-Suk Jo; Kyungseon Joo; Henry Juengst; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Andreas Klein; Franz Klein; Alexei Klimenko; Mikhail Kossov; Laird Kramer; V. Kubarovsky; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Jeff Lachniet; Jorn Langheinrich; David Lawrence; Tsung-shung Lee; Kenneth Livingston; H. Lu; Marion MacCormick; Nikolai Markov; Bernhard Mecking

    2006-01-01

    For the first time, the reaction gamma d -> Lambda n K+ has been analyzed in order to search for the exotic pentaquark baryon Theta+(1540). The data were taken at Jefferson Lab, using the Hall-B tagged-photon beam of energy between 0.8 and 3.6 GeV and the CEBAF Large Acceptance Spectrometer (CLAS). No statistically significant structures were observed in the nK+ invariant mass distribution. The upper limit on the gamma d -> Lambda Theta+ integrated cross section has been calculated and found to be between 5 and 25 nb, depending on the production model assumed. The upper limit on the differential cross section is also reported

  12. Continuous theta burst demonstrates a causal role of premotor homunculus in action interpretation

    DEFF Research Database (Denmark)

    Michael, John Andrew

    2014-01-01

    Although it is well established that regions of premotor cortex (PMC) are active during action observation, it remains controversial whether they play a causal role in action understanding. In the experiment reported here, we used off-line continuous theta-burst stimulation (cTBS) to investigate ...

  13. Computer simulation of plasma behavior in open-ended linear theta machines. Scientific report 81-5

    Energy Technology Data Exchange (ETDEWEB)

    Stover, E. K.

    1981-04-01

    Zero-dimensional and one-dimensional fluid plasma computer models have been developed to study the behavior of linear theta pinch plasmas. Computer simulation results generated from these codes are compared with data obtained from two theta pinch experiments so that significant machine plasma behavior can be identified. The experiments examined are a collisional experiment, T/sub i/ approx. 50 eV, n/sub e/ approx. 10/sup 17/ cm/sup -3/, where the plasma mean-free-path was significantly less than the plasma column length, and a hot ion species experiment, T/sub i/ approx. 3 keV, n/sub e/ approx. 10/sup 16/ cm/sup -3/, where the ion mean-free-path was on the order of the plasma column length.

  14. Engineering and physics considerations for a linear theta-pinch hybrid reactor (LTPHR)

    International Nuclear Information System (INIS)

    Krakowski, R.A.; Miller, R.L.; Hagenson, R.L.

    1976-01-01

    A fusion-fission hybrid reactor based on pulsed, high-β, linear theta-pinch magnetic confinement is considered. A preliminary design which incorporates key physics, engineering and economic considerations is presented. An extensive presentation of the system energy balance is made, and this energy balance is evaluated parametrically. The feasibility of end-loss reduction is addressed

  15. Brandt matrices and theta series over global function fields

    CERN Document Server

    Chuang, Chih-Yun; Wei, Fu-Tsun; Yu, Jing

    2015-01-01

    The aim of this article is to give a complete account of the Eichler-Brandt theory over function fields and the basis problem for Drinfeld type automorphic forms. Given arbitrary function field k together with a fixed place \\infty, the authors construct a family of theta series from the norm forms of "definite" quaternion algebras, and establish an explicit Hecke-module homomorphism from the Picard group of an associated definite Shimura curve to a space of Drinfeld type automorphic forms. The "compatibility" of these homomorphisms with different square-free levels is also examined. These Heck

  16. Gender difference in the theta/alpha ratio during the induction of peaceful audiovisual modalities.

    Science.gov (United States)

    Yang, Chia-Yen; Lin, Ching-Po

    2015-09-01

    Gender differences in emotional perception have been found in numerous psychological and psychophysiological studies. The conducting modalities in diverse characteristics of different sensory systems make it interesting to determine how cooperation and competition contribute to emotional experiences. We have previously estimated the bias from the match attributes of auditory and visual modalities and revealed specific brain activity frequency patterns related to a peaceful mood. In that multimodality experiment, we focused on how inner-quiet information is processed in the human brain, and found evidence of auditory domination from the theta-band activity. However, a simple quantitative description of these three frequency bands is lacking, and no studies have assessed the effects of peacefulness on the emotional state. Therefore, the aim of this study was to use magnetoencephalography to determine if gender differences exist (and when and where) in the frequency interactions underpinning the perception of peacefulness. This study provides evidence of auditory and visual domination in perceptual bias during multimodality processing of peaceful consciousness. The results of power ratio analyses suggest that the values of the theta/alpha ratio are associated with a modality as well as hemispheric asymmetries in the anterior-to-posterior direction, which shift from right to left with the auditory to visual stimulations in a peaceful mood. This means that the theta/alpha ratio might be useful for evaluating emotion. Moreover, the difference was found to be most pronounced for auditory domination and visual sensitivity in the female group.

  17. The fate of close encounters between binary stars and binary supermassive black holes

    Science.gov (United States)

    Wang, Yi-Han; Leigh, Nathan; Yuan, Ye-Fei; Perna, Rosalba

    2018-04-01

    The evolution of main-sequence binaries that reside in the Galactic Centre can be heavily influenced by the central supermassive black hole (SMBH). Due to these perturbative effects, the stellar binaries in dense environments are likely to experience mergers, collisions, or ejections through secular and/or non-secular interactions. More direct interactions with the central SMBH are thought to produce hypervelocity stars (HVSs) and tidal disruption events (TDEs). In this paper, we use N-body simulations to study the dynamics of stellar binaries orbiting a central SMBH primary with an outer SMBH secondary orbiting this inner triple. The effects of the secondary SMBH on the event rates of HVSs, TDEs, and stellar mergers are investigated, as a function of the SMBH-SMBH binary mass ratio. Our numerical experiments reveal that, relative to the isolated SMBH case, the TDE and HVS rates are enhanced for, respectively, the smallest and largest mass ratio SMBH-SMBH binaries. This suggests that the observed event rates of TDEs and HVSs have the potential to serve as a diagnostic of the mass ratio of a central SMBH-SMBH binary. The presence of a secondary SMBH also allows for the creation of hypervelocity binaries. Observations of these systems could thus constrain the presence of a secondary SMBH in the Galactic Centre.

  18. Solving a binary puzzle

    NARCIS (Netherlands)

    Utomo, P.H.; Makarim, R.H.

    2017-01-01

    A Binary puzzle is a Sudoku-like puzzle with values in each cell taken from the set {0,1} {0,1}. Let n≥4 be an even integer, a solved binary puzzle is an n×n binary array that satisfies the following conditions: (1) no three consecutive ones and no three consecutive zeros in each row and each

  19. Studies on the Utilization, Metabolism and Function of Sterols in the House-Fly, Musca Domestica; Utilisation. Metabolisme et fonctions des sterols chez la mouche domestique (Musca Domestica); Izuchenie usvoeniya, metabolizma i funktsii sterinov v organizme domashnej mukhi Musca Domestica; Estudios sobre la asimilacion, el metabolismo y la funcion de los esteroles in la mosca comun (Musca Domestica)

    Energy Technology Data Exchange (ETDEWEB)

    Robbins, W. E. [United States Department of Agriculture, Agricultural Research Service, Entomology Research Division, Beltsville, MD (United States)

    1963-09-15

    Insects generally have been found to require a dietary source of sterol for normal larval growth and metamorphosis. Our work has pointed to two additional physiological roles for sterols in the housefly, Musca domestica L.: (1) A dietary source of sterol is essential for sustained viable egg production in the female fly; on a sterol-deficient diet eggs are produced but hatch and viability are low. (2) Cholesterol is also involved in the mobilization and utilization of nutrient reserves associated with the initiation of ovarian maturation in the female fly. The quantitative sterol requirements for the above physiological processes and the metabolic conversions that occur during growth, metamorphosis and reproduction have been studied in this insect, using C{sup 14}- and H{sup 3}-labelled sterols in conjunction with a variety of analytical tools, including reverse isotope dilution, gasliquid chromatography and spectroscopy, and employing aseptic rearing techniques and semi-defined larval and Adult diets. Both C{sup 14}-cholesterol and H{sup 3}-{beta}- sitosterol have been used as a source df sterol in either the larval or the adult diet of the house fly, and the pattern of utilization and metabolism was found to be almost identical for these two sterols. However, there was no detectable conversion of {beta}-sitosterol to cholesterol. Sub-minimal quantities of cholesterol have also been used in the larval diet in combination with ''sparing sterols'' such as choies tanol, which will fulfill in part but not entirely the sterol requirement of this insect. The utilization and fate of the 'sparing sterol' has been investigated using C{sup 14} cholestanol, and the metabolism of the minute quantity of essential cholesterol is currently under study using high-specific-activity C{sup 14} cholesterol. - Other species of insects, including the German cockroach (Blattella germanica), have been examined in relation to the patterns of utilization and the metabolic pathways for

  20. Distinct roles of theta and alpha oscillations in the involuntary capture of goal-directed attention.

    Science.gov (United States)

    Harris, Anthony M; Dux, Paul E; Jones, Caelyn N; Mattingley, Jason B

    2017-05-15

    Mechanisms of attention assign priority to sensory inputs on the basis of current task goals. Previous studies have shown that lateralized neural oscillations within the alpha (8-14Hz) range are associated with the voluntary allocation of attention to the contralateral visual field. It is currently unknown, however, whether similar oscillatory signatures instantiate the involuntary capture of spatial attention by goal-relevant stimulus properties. Here we investigated the roles of theta (4-8Hz), alpha, and beta (14-30Hz) oscillations in human goal-directed visual attention. Across two experiments, we had participants respond to a brief target of a particular color among heterogeneously colored distractors. Prior to target onset, we cued one location with a lateralized, non-predictive cue that was either target- or non-target-colored. During the behavioral task, we recorded brain activity using electroencephalography (EEG), with the aim of analyzing cue-elicited oscillatory activity. We found that theta oscillations lateralized in response to all cues, and this lateralization was stronger if the cue matched the target color. Alpha oscillations lateralized relatively later, and only in response to target-colored cues, consistent with the capture of spatial attention. Our findings suggest that stimulus induced changes in theta and alpha amplitude reflect task-based modulation of signals by feature-based and spatial attention, respectively. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Resting-state theta band connectivity and graph analysis in generalized social anxiety disorder.

    Science.gov (United States)

    Xing, Mengqi; Tadayonnejad, Reza; MacNamara, Annmarie; Ajilore, Olusola; DiGangi, Julia; Phan, K Luan; Leow, Alex; Klumpp, Heide

    2017-01-01

    Functional magnetic resonance imaging (fMRI) resting-state studies show generalized social anxiety disorder (gSAD) is associated with disturbances in networks involved in emotion regulation, emotion processing, and perceptual functions, suggesting a network framework is integral to elucidating the pathophysiology of gSAD. However, fMRI does not measure the fast dynamic interconnections of functional networks. Therefore, we examined whole-brain functional connectomics with electroencephalogram (EEG) during resting-state. Resting-state EEG data was recorded for 32 patients with gSAD and 32 demographically-matched healthy controls (HC). Sensor-level connectivity analysis was applied on EEG data by using Weighted Phase Lag Index (WPLI) and graph analysis based on WPLI was used to determine clustering coefficient and characteristic path length to estimate local integration and global segregation of networks. WPLI results showed increased oscillatory midline coherence in the theta frequency band indicating higher connectivity in the gSAD relative to HC group during rest. Additionally, WPLI values positively correlated with state anxiety levels within the gSAD group but not the HC group. Our graph theory based connectomics analysis demonstrated increased clustering coefficient and decreased characteristic path length in theta-based whole brain functional organization in subjects with gSAD compared to HC. Theta-dependent interconnectivity was associated with state anxiety in gSAD and an increase in information processing efficiency in gSAD (compared to controls). Results may represent enhanced baseline self-focused attention, which is consistent with cognitive models of gSAD and fMRI studies implicating emotion dysregulation and disturbances in task negative networks (e.g., default mode network) in gSAD.

  2. Deqi Induction by HT7 Acupuncture Alters Theta and Alpha Band Coherence in Human Healthy Subjects

    Directory of Open Access Journals (Sweden)

    Go-Eun Lee

    2017-01-01

    Full Text Available The aim of this preliminary study is to investigate the changes in phase synchronization in the theta and alpha bands before and during the performance of classical acupuncture on the Sinmun (HT7. The electroencephalogram (EEG signals from nine healthy young subjects were recorded before and during acupuncture in the “closed-eye” state. The EEG signals were acquired from 19 surface scalp electrodes (FP1, FP2, F7, F3, Fz F4, F8, T3, C3, Cz, C4, T4, T5, P3, Pz, P4, T6, O1, and O2. Needles were inserted into the HT7 bilaterally and were then manipulated to induce deqi and retained for 15 minutes. Phase synchronization was measured by phase coherence. In the theta band, coherence significantly increased between the temporal (T5, T6 and occipital areas (O1, O2 during the acupuncture stimulation. In the alpha band, coherence significantly increased between the left temporal area (T5 and other areas (frontal, parietal, and occipital. Phase coherence in the theta and alpha bands tended to increase during the retention of the acupuncture needles after deqi. Therefore, it can be concluded that acupuncture stimulation with deqi is clinically effective via the central nervous system (CNS.

  3. Higher theta and alpha1 coherence when listening to Vedic recitation compared to coherence during Transcendental Meditation practice.

    Science.gov (United States)

    Travis, Frederick; Parim, Niyazi; Shrivastava, Amrita

    2017-03-01

    This study compared subjective experiences and EEG patterns in 37 subjects when listening to live Vedic recitation and when practicing Transcendental Meditation (TM). Content analysis of experiences when listening to Vedic recitation yielded three higher-order code. Experiences during Vedic recitation were: (1) deeper than during TM practice; (2) experienced as an inner process; and (3) characterized by lively silence. EEG patterns support these higher-order codes. Theta2 and alpha1 frontal, parietal, and frontal-parietal coherence were significantly higher when listening to Vedic recitation, than during TM practice. Theta2 coherence is seen when attending to internal mental processes. Higher theta2 coherence supports subjects' descriptions that the Vedic recitations were "not external sounds but internal vibrations." Alpha1 coherence is reported during pure consciousness experiences during TM practice. Higher alpha1 coherence supports subjects' descriptions that they "experienced a depth of experience, rarely experienced even during deep TM practice." These data support the utility of listening to Vedic recitation to culture deep inner experiences. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Effect of Triflumuron and Pyriproxyfen on Musca domestica L Larval Stages in the Laboratory

    Directory of Open Access Journals (Sweden)

    S Sulaiman

    2008-08-01

    Full Text Available Background:  The residual effect of triflumuron and pyriproxyfen on Musca domestica L larval stages was studied in the laboratory."n"nMethods: Both IGRs at varying concentrations ranging between 0.5 to 2.5 mg/L were placed inside beakers with mice chow and vitamin B complex and water as food for the 1st, 2nd and 3rd instars M.domestica larvae."n"nResults: Both IGRs inhibit M. domestica adult emergence of 98-98.5% when applied at the lowest concentration of 0.5 mg/L on the 1st instar, 93-97% of adult emergence inhibition on the 2nd instar,and 91-97% of adult emergence inhibi­tion on the 3rd instar larvae respectively. There was no significant difference between triflumuron and pyriproxy­fen on house­fly adult emergence inhibition when fed to the 1st, 2nd and 3rd instars M.domestica larvae (P> 0.05. However, there was a significant difference between the IGRs and the control (P< 0.05."n"nConclusion: Both triflumuron and pyriproxyfen are effective in inhibiting adult emergence of housefly M  domes­tica and therefore should be recommended for fly control particularly in chicken farms and dumping grounds in Malaysia for housefly control activities.

  5. Relativistic Binaries in Globular Clusters

    Directory of Open Access Journals (Sweden)

    Matthew J. Benacquista

    2013-03-01

    Full Text Available Galactic globular clusters are old, dense star systems typically containing 10^4 – 10^6 stars. As an old population of stars, globular clusters contain many collapsed and degenerate objects. As a dense population of stars, globular clusters are the scene of many interesting close dynamical interactions between stars. These dynamical interactions can alter the evolution of individual stars and can produce tight binary systems containing one or two compact objects. In this review, we discuss theoretical models of globular cluster evolution and binary evolution, techniques for simulating this evolution that leads to relativistic binaries, and current and possible future observational evidence for this population. Our discussion of globular cluster evolution will focus on the processes that boost the production of tight binary systems and the subsequent interaction of these binaries that can alter the properties of both bodies and can lead to exotic objects. Direct N-body integrations and Fokker–Planck simulations of the evolution of globular clusters that incorporate tidal interactions and lead to predictions of relativistic binary populations are also discussed. We discuss the current observational evidence for cataclysmic variables, millisecond pulsars, and low-mass X-ray binaries as well as possible future detection of relativistic binaries with gravitational radiation.

  6. Energy- and particle-confinement properties of an end-plugged, linear, theta pinch

    International Nuclear Information System (INIS)

    Commisso, R.J.; Bartsch, R.R.; Ekdahl, C.A.; McKenna, K.F.; Siemon, R.E.

    1979-01-01

    Experiments show that axial confinement of plasma in a straight theta-pinch solenoid is improved by placing solid lithium deuteride plugs at the ends. The energy confinement is increased nearly threefold in agreement with theoretical estimates which assume classical electron thermal conduction and no convective losses. The confinement of deuterium ions is explained by classical Coulomb collisions in the ablated lithium deuteride plasma

  7. Plasma behaviors in the open field region of reversed-field theta-pinch

    International Nuclear Information System (INIS)

    Aso, Yoshiyuki; Hirano, Keiichi.

    1983-03-01

    A characteristic behavior of the plasma in an open field region of reversed field theta pinch has been studied with the guide field (GF) which extends the field line along the axial direction. The experimental result suggests that the rotaional instability may be induced in FRC after the plasma touches the wall at the ends of the open field. (author)

  8. A neural signature of fairness in altruism: a game of theta?

    Science.gov (United States)

    Rodrigues, Johannes; Ulrich, Natalie; Hewig, Johannes

    2015-04-01

    In the dictator game, a proposer can share a certain amount of money between himself or herself and a receiver, who has no opportunity of influencing the offer. Rational choice theory predicts that dictators keep all money for themselves. But people often are offering money to receivers, despite their opportunity to maximize their own profit and therefore showing altruistic behavior. In this study, we investigated the influence of the altruism of the dictator, the anonymity of the decision and the income of the receiver on the offer made by a dictator. Additionally, we were interested in the influence of midfrontal theta activity prior to the offer, indicating the upcoming decision. The height of the offer made by the dictator was dependent on all variables investigated: Altruism of the dictator led to higher offers and income of the receiver led to higher offer the poorer the receivers are. The anonymity of the decision had two effects, depending on the altruism of the dictator, with higher offers for highly altruistic dictators, when they were not observed, and lower offers for less altruistic dictators in this condition. Finally, midfrontal theta activity predicts upcoming fair offers, maybe indicating altruistic motivation or empathy on physiological basis.

  9. Cognitive control during audiovisual working memory engages frontotemporal theta-band interactions.

    Science.gov (United States)

    Daume, Jonathan; Graetz, Sebastian; Gruber, Thomas; Engel, Andreas K; Friese, Uwe

    2017-10-03

    Working memory (WM) maintenance of sensory information has been associated with enhanced cross-frequency coupling between the phase of low frequencies and the amplitude of high frequencies, particularly in medial temporal lobe (MTL) regions. It has been suggested that these WM maintenance processes are controlled by areas of the prefrontal cortex (PFC) via frontotemporal phase synchronisation in low frequency bands. Here, we investigated whether enhanced cognitive control during audiovisual WM as compared to visual WM alone is associated with increased low-frequency phase synchronisation between sensory areas maintaining WM content and areas from PFC. Using magnetoencephalography, we recorded neural oscillatory activity from healthy human participants engaged in an audiovisual delayed-match-to-sample task. We observed that regions from MTL, which showed enhanced theta-beta phase-amplitude coupling (PAC) during the WM delay window, exhibited stronger phase synchronisation within the theta-band (4-7 Hz) to areas from lateral PFC during audiovisual WM as compared to visual WM alone. Moreover, MTL areas also showed enhanced phase synchronisation to temporooccipital areas in the beta-band (20-32 Hz). Our results provide further evidence that a combination of long-range phase synchronisation and local PAC might constitute a mechanism for neuronal communication between distant brain regions and across frequencies during WM maintenance.

  10. Functional localization and effective connectivity of cortical theta and alpha oscillatory activity during an attention task

    Directory of Open Access Journals (Sweden)

    Yuichi Kitaura

    Full Text Available Objectives: The aim of this paper is to investigate cortical electric neuronal activity as an indicator of brain function, in a mental arithmetic task that requires sustained attention, as compared to the resting state condition. The two questions of interest are the cortical localization of different oscillatory activities, and the directional effective flow of oscillatory activity between regions of interest, in the task condition compared to resting state. In particular, theta and alpha activity are of interest here, due to their important role in attention processing. Methods: We adapted mental arithmetic as an attention ask in this study. Eyes closed 61-channel EEG was recorded in 14 participants during resting and in a mental arithmetic task (“serial sevens subtraction”. Functional localization and connectivity analyses were based on cortical signals of electric neuronal activity estimated with sLORETA (standardized low resolution electromagnetic tomography. Functional localization was based on the comparison of the cortical distributions of the generators of oscillatory activity between task and resting conditions. Assessment of effective connectivity was based on the iCoh (isolated effective coherence method, which provides an appropriate frequency decomposition of the directional flow of oscillatory activity between brain regions. Nine regions of interest comprising nodes from the dorsal and ventral attention networks were selected for the connectivity analysis. Results: Cortical spectral density distribution comparing task minus rest showed significant activity increase in medial prefrontal areas and decreased activity in left parietal lobe for the theta band, and decreased activity in parietal-occipital regions for the alpha1 band. At a global level, connections among right hemispheric nodes were predominantly decreased during the task condition, while connections among left hemispheric nodes were predominantly increased. At more

  11. Kinesthetic motor imagery training modulates frontal midline theta during imagination of a dart throw.

    Science.gov (United States)

    Weber, E; Doppelmayr, M

    2016-12-01

    Motor imagery (MI) is a frequently used and effective method for motor learning in sports as well as in other domains. Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) studies indicated that experts within a certain sport exhibit a more pronounced brain activity during MI as compared to novices. Similar to the execution, during MI the motor sequence has to be planned. Thus, the frontal attentional system, in part represented by the frontal midline theta (4-7Hz), is closely related to these processes and presumably plays a major role in MI as well. In this study, a MI dart training and its impact on frontal midline theta activity (fmt) during MI are examined. 53 healthy subjects with no prior dart experience were randomly allocated to a kinesthetic training group (KinVis) or to a control group (Control). Both groups performed 15 training sessions. While in the KinVis group dart throwing was accompanied by MI, the Control group trained without MI. Dart performance and fmt activity during MI within the first and the 15th session were compared. As expected, the performance increase was more pronounced in the KinVis group. Furthermore, frontal theta amplitude was significantly increased in the KinVis group during MI in the 15th training session as compared to the baseline. These results confirm the effectivity of MI. The enhanced fmt activity in the KinVis group can be interpreted as a better allocation of the requested resources in the frontal attentional network after MI. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Skewed Binary Search Trees

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Moruz, Gabriel

    2006-01-01

    It is well-known that to minimize the number of comparisons a binary search tree should be perfectly balanced. Previous work has shown that a dominating factor over the running time for a search is the number of cache faults performed, and that an appropriate memory layout of a binary search tree...... can reduce the number of cache faults by several hundred percent. Motivated by the fact that during a search branching to the left or right at a node does not necessarily have the same cost, e.g. because of branch prediction schemes, we in this paper study the class of skewed binary search trees....... For all nodes in a skewed binary search tree the ratio between the size of the left subtree and the size of the tree is a fixed constant (a ratio of 1/2 gives perfect balanced trees). In this paper we present an experimental study of various memory layouts of static skewed binary search trees, where each...

  13. The Dynamics of Networks of Identical Theta Neurons.

    Science.gov (United States)

    Laing, Carlo R

    2018-02-05

    We consider finite and infinite all-to-all coupled networks of identical theta neurons. Two types of synaptic interactions are investigated: instantaneous and delayed (via first-order synaptic processing). Extensive use is made of the Watanabe/Strogatz (WS) ansatz for reducing the dimension of networks of identical sinusoidally-coupled oscillators. As well as the degeneracy associated with the constants of motion of the WS ansatz, we also find continuous families of solutions for instantaneously coupled neurons, resulting from the reversibility of the reduced model and the form of the synaptic input. We also investigate a number of similar related models. We conclude that the dynamics of networks of all-to-all coupled identical neurons can be surprisingly complicated.

  14. Binary optics: Trends and limitations

    Science.gov (United States)

    Farn, Michael W.; Veldkamp, Wilfrid B.

    1993-01-01

    We describe the current state of binary optics, addressing both the technology and the industry (i.e., marketplace). With respect to the technology, the two dominant aspects are optical design methods and fabrication capabilities, with the optical design problem being limited by human innovation in the search for new applications and the fabrication issue being limited by the availability of resources required to improve fabrication capabilities. With respect to the industry, the current marketplace does not favor binary optics as a separate product line and so we expect that companies whose primary purpose is the production of binary optics will not represent the bulk of binary optics production. Rather, binary optics' more natural role is as an enabling technology - a technology which will directly result in a competitive advantage in a company's other business areas - and so we expect that the majority of binary optics will be produced for internal use.

  15. Black holes in binary stars

    NARCIS (Netherlands)

    Wijers, R.A.M.J.

    1996-01-01

    Introduction Distinguishing neutron stars and black holes Optical companions and dynamical masses X-ray signatures of the nature of a compact object Structure and evolution of black-hole binaries High-mass black-hole binaries Low-mass black-hole binaries Low-mass black holes Formation of black holes

  16. Coevolution of Binaries and Circumbinary Gaseous Disks

    Science.gov (United States)

    Fleming, David; Quinn, Thomas R.

    2018-04-01

    The recent discoveries of circumbinary planets by Kepler raise questions for contemporary planet formation models. Understanding how these planets form requires characterizing their formation environment, the circumbinary protoplanetary disk, and how the disk and binary interact. The central binary excites resonances in the surrounding protoplanetary disk that drive evolution in both the binary orbital elements and in the disk. To probe how these interactions impact both binary eccentricity and disk structure evolution, we ran N-body smooth particle hydrodynamics (SPH) simulations of gaseous protoplanetary disks surrounding binaries based on Kepler 38 for 10^4 binary orbital periods for several initial binary eccentricities. We find that nearly circular binaries weakly couple to the disk via a parametric instability and excite disk eccentricity growth. Eccentric binaries strongly couple to the disk causing eccentricity growth for both the disk and binary. Disks around sufficiently eccentric binaries strongly couple to the disk and develop an m = 1 spiral wave launched from the 1:3 eccentric outer Lindblad resonance (EOLR). This wave corresponds to an alignment of gas particle longitude of periastrons. We find that in all simulations, the binary semi-major axis decays due to dissipation from the viscous disk.

  17. BINARY CEPHEIDS: SEPARATIONS AND MASS RATIOS IN 5 M ☉ BINARIES

    International Nuclear Information System (INIS)

    Evans, Nancy Remage; Karovska, Margarita; Tingle, Evan; Bond, Howard E.; Schaefer, Gail H.; Mason, Brian D.

    2013-01-01

    Deriving the distribution of binary parameters for a particular class of stars over the full range of orbital separations usually requires the combination of results from many different observing techniques (radial velocities, interferometry, astrometry, photometry, direct imaging), each with selection biases. However, Cepheids—cool, evolved stars of ∼5 M ☉ —are a special case because ultraviolet (UV) spectra will immediately reveal any companion star hotter than early type A, regardless of the orbital separation. We have used International Ultraviolet Explorer UV spectra of a complete sample of all 76 Cepheids brighter than V = 8 to create a list of all 18 Cepheids with companions more massive than 2.0 M ☉ . Orbital periods of many of these binaries are available from radial-velocity studies, or can be estimated for longer-period systems from detected velocity variability. In an imaging survey with the Hubble Space Telescope Wide Field Camera 3, we resolved three of the companions (those of η Aql, S Nor, and V659 Cen), allowing us to make estimates of the periods out to the long-period end of the distribution. Combining these separations with orbital data in the literature, we derive an unbiased distribution of binary separations, orbital periods, and mass ratios. The distribution of orbital periods shows that the 5 M ☉ binaries have systematically shorter periods than do 1 M ☉ stars. Our data also suggest that the distribution of mass ratios depends on both binary separation and system multiplicity. The distribution of mass ratios as a function of orbital separation, however, does not depend on whether a system is a binary or a triple

  18. A comparative study of long-baseline superbeams within LAGUNA for large $\\theta_{13}$

    CERN Document Server

    Coloma, Pilar; Pascoli, Silvia

    2012-01-01

    The Daya Bay and RENO experiments have recently observed a non-zero $\\theta_{13}$ at more than $5\\sigma$ CL. This has important consequences for future neutrino oscillation experiments. We analyze these within the LAGUNA design study which considers seven possible locations for a European neutrino observatory for proton decay, neutrino, and astroparticle physics. The megaton-scale detector would be an ideal target for a CERN-based neutrino beam with baselines ranging from 130 km to 2300 km. We perform a detailed study to assess the physics reach of the three detector options - a 440 kton water \\v{C}erenkov, a 100 kton liquid argon and a 50 kton liquid scintillator detector - at each of the possible locations, taking into account the recent measurement of $\\theta_{13}$. We study the impact of the beam properties and detector performances on the sensitivity to CP-violation and the mass hierarchy. We find that a liquid argon or water \\v{C}erenkov detector can make a $3\\sigma$ discovery of CP violation for $60%-7...

  19. Compact toroid formation using barrier fields and controlled reconnection in the TRX-1 field reversed theta pinch

    International Nuclear Information System (INIS)

    Hoffman, A.L.; Armstrong, W.T.

    1982-01-01

    TRX-1 is a new 20 cm diameter, 1-m long field reversed theta pinch with a magnetic field swing of 10 kG in 3 μsec. It employs z discharge preionization and octopole barrier fields to maximize flux trapping on first half cycle operation. Cusp coils are used at the theta pinch ends to delay reconnection and fast mirror coils are used to trigger reconnection at a time designed to maximize axial heating efficiency and toroid lifetime. These controls are designed to study toroid formation methods which are claimed to be especially efficient by Russian experimenters. Studies have been conducted on flux trapping efficiency, triggered reconnection, and equilibrium and lifetime

  20. Spectral properties of binary asteroids

    Science.gov (United States)

    Pajuelo, Myriam; Birlan, Mirel; Carry, Benoît; DeMeo, Francesca E.; Binzel, Richard P.; Berthier, Jérôme

    2018-04-01

    We present the first attempt to characterize the distribution of taxonomic class among the population of binary asteroids (15% of all small asteroids). For that, an analysis of 0.8-2.5{μ m} near-infrared spectra obtained with the SpeX instrument on the NASA/IRTF is presented. Taxonomic class and meteorite analog is determined for each target, increasing the sample of binary asteroids with known taxonomy by 21%. Most binary systems are bound in the S-, X-, and C- classes, followed by Q and V-types. The rate of binary systems in each taxonomic class agrees within uncertainty with the background population of small near-Earth objects and inner main belt asteroids, but for the C-types which are under-represented among binaries.

  1. LTPF: a linear theta-pinch neutron source

    International Nuclear Information System (INIS)

    Ellis, W.R.

    1975-07-01

    The linear theta pinch is optimized with respect to maximum neutron current on a sample located between the discharge tube and the compression coil wall. Emphasis throughout is placed on physics and technology considerations which govern the choice of parameters. Technological demands are (hopefully) kept to a minimum. Two ''point designs'' are developed which are distinguished by their compressional magnetic field (i.e., coil current) wave-forms: one is sinusoidal and continuous, the other trapezoidal and pulsed intermittently. Both point designs give an average neutron current of approximately 5 x 10 13 n/cm 2 /s. Both devices are characterized by short lengths (approximately 1 m), rapid cycling (2 to 30 kHz), and magnetic mirrors (2 to 5:1) at the ends. A crucial item is the power supply, which is discussed in detail. (U.S.)

  2. Cost estimation for a theta-pinch reactor

    International Nuclear Information System (INIS)

    Coultas, T.A.; Cook, J.M.; Crnkovich, P.; Dauzvardis, P.

    1976-02-01

    A simulation of a theta-pinch fusion power plant has been completed to the point where economic feasibility can be examined. A PL/I cost subprogram is presented for interfacing with the computer code TPFPP. This code is then used to obtain a first approximation of the costs for the reactor. Independent geometrical and plant design parameters are varied over a wide range, with simultaneous variation of magnetic field, minor first wall radius, and plasma maximum compression. The study indicates that the plant energy balance must be favorable, availability must be high, and major component costs must be low to achieve economical results. Although costing uncertainties remain, it is clear that development of easy and rapid replacement methods for reactor components is essential and that new staging concepts to reduce the implosion energy requirement must be pursued

  3. Persistent hyperdopaminergia decreases the peak frequency of hippocampal theta oscillations during quiet waking and REM sleep.

    Directory of Open Access Journals (Sweden)

    Kafui Dzirasa

    Full Text Available Long-term changes in dopaminergic signaling are thought to underlie the pathophysiology of a number of psychiatric disorders. Several conditions are associated with cognitive deficits such as disturbances in attention processes and learning and memory, suggesting that persistent changes in dopaminergic signaling may alter neural mechanisms underlying these processes. Dopamine transporter knockout (DAT-KO mice exhibit a persistent five-fold increase in extracellular dopamine levels. Here, we demonstrate that DAT-KO mice display lower hippocampal theta oscillation frequencies during baseline periods of waking and rapid-eye movement sleep. These altered theta oscillations are not reversed via treatment with the antidopaminergic agent haloperidol. Thus, we propose that persistent hyperdopaminergia, together with secondary alterations in other neuromodulatory systems, results in lower frequency activity in neural systems responsible for various cognitive processes.

  4. Simulation of the implosion of a theta pinch

    International Nuclear Information System (INIS)

    Busnardo Neto, J.; Leite Neto, J.P.; Jesus Paes, A.C. de

    1982-01-01

    A two-fluid model was used to simulate the implosion of a theta-pinch, with initial densities varying from 10 12 to 10 16 cm -3 . The gases used were hydrogen, helium, neon and argon; initial temperatures of 2 eV and total ionization were assumed. For hydrogen the anomalous resistivity is dominant everywhere when the density is low (ν sub(eff) - ω sub(pi)). For high densities both resistivities are not high enough to allow diffusion of the magnetic field during the time of the implosion (ν sub(eff) approximatelly 0.3 ω sub(pi)). For heavier gases a surprisingly high value of the anomalous resistivity was found, due to the greater mass, (ν sub(eff) approximatelly 10-12 ω sub(pi)). (Author) [pt

  5. Binary Cepheids: Separations and Mass Ratios in 5 M ⊙ Binaries

    Science.gov (United States)

    Evans, Nancy Evans; Bond, Howard E.; Schaefer, Gail H.; Mason, Brian D.; Karovska, Margarita; Tingle, Evan

    2013-10-01

    Deriving the distribution of binary parameters for a particular class of stars over the full range of orbital separations usually requires the combination of results from many different observing techniques (radial velocities, interferometry, astrometry, photometry, direct imaging), each with selection biases. However, Cepheids—cool, evolved stars of ~5 M ⊙—are a special case because ultraviolet (UV) spectra will immediately reveal any companion star hotter than early type A, regardless of the orbital separation. We have used International Ultraviolet Explorer UV spectra of a complete sample of all 76 Cepheids brighter than V = 8 to create a list of all 18 Cepheids with companions more massive than 2.0 M ⊙. Orbital periods of many of these binaries are available from radial-velocity studies, or can be estimated for longer-period systems from detected velocity variability. In an imaging survey with the Hubble Space Telescope Wide Field Camera 3, we resolved three of the companions (those of η Aql, S Nor, and V659 Cen), allowing us to make estimates of the periods out to the long-period end of the distribution. Combining these separations with orbital data in the literature, we derive an unbiased distribution of binary separations, orbital periods, and mass ratios. The distribution of orbital periods shows that the 5 M ⊙ binaries have systematically shorter periods than do 1 M ⊙ stars. Our data also suggest that the distribution of mass ratios depends on both binary separation and system multiplicity. The distribution of mass ratios as a function of orbital separation, however, does not depend on whether a system is a binary or a triple. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained by the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  6. The formation of eccentric compact binary inspirals and the role of gravitational wave emission in binary-single stellar encounters

    International Nuclear Information System (INIS)

    Samsing, Johan; MacLeod, Morgan; Ramirez-Ruiz, Enrico

    2014-01-01

    The inspiral and merger of eccentric binaries leads to gravitational waveforms distinct from those generated by circularly merging binaries. Dynamical environments can assemble binaries with high eccentricity and peak frequencies within the LIGO band. In this paper, we study binary-single stellar scatterings occurring in dense stellar systems as a source of eccentrically inspiraling binaries. Many interactions between compact binaries and single objects are characterized by chaotic resonances in which the binary-single system undergoes many exchanges before reaching a final state. During these chaotic resonances, a pair of objects has a non-negligible probability of experiencing a very close passage. Significant orbital energy and angular momentum are carried away from the system by gravitational wave (GW) radiation in these close passages, and in some cases this implies an inspiral time shorter than the orbital period of the bound third body. We derive the cross section for such dynamical inspiral outcomes through analytical arguments and through numerical scattering experiments including GW losses. We show that the cross section for dynamical inspirals grows with increasing target binary semi-major axis a and that for equal-mass binaries it scales as a 2/7 . Thus, we expect wide target binaries to predominantly contribute to the production of these relativistic outcomes. We estimate that eccentric inspirals account for approximately 1% of dynamically assembled non-eccentric merging binaries. While these events are rare, we show that binary-single scatterings are a more effective formation channel than single-single captures for the production of eccentrically inspiraling binaries, even given modest binary fractions.

  7. (No) Time for control: Frontal theta dynamics reveal the cost of temporally guided conflict anticipation

    NARCIS (Netherlands)

    van Driel, J.; Swart, J.C.; Egner, T.; Ridderinkhof, K.R.; Cohen, M.

    2015-01-01

    During situations of response conflict, cognitive control is characterized by prefrontal theta-band (3- to 8-Hz) activity. It has been shown that cognitive control can be triggered proactively by contextual cues that predict conflict. Here, we investigated whether a pretrial preparation interval

  8. (No) time for control: frontal theta dynamics reveal the cost of temporally guided conflict anticipation

    NARCIS (Netherlands)

    van Driel, J.; Swart, J.C.; Egner, T.; Ridderinkhof, K.R.; Cohen, M.X.

    2015-01-01

    During situations of response conflict, cognitive control is characterized by prefrontal theta-band (3- to 8-Hz) activity. It has been shown that cognitive control can be triggered proactively by contextual cues that predict conflict. Here, we investigated whether a pretrial preparation interval

  9. The Effects of Sex-Ratio and Density on Locomotor Activity in the House Fly, Musca domestica

    Science.gov (United States)

    Bahrndorff, Simon; Kjærsgaard, Anders; Pertoldi, Cino; Loeschcke, Volker; Schou, Toke M.; Skovgård, Henrik; Hald, Birthe

    2012-01-01

    Although locomotor activity is involved in almost all behavioral traits, there is a lack of knowledge on what factors affect it. This study examined the effects of sex—ratio and density on the circadian rhythm of locomotor activity of adult Musca domestica L. (Diptera: Muscidae) using an infra—red light system. Sex—ratio significantly affected locomotor activity, increasing with the percentage of males in the vials. In accordance with other studies, males were more active than females, but the circadian rhythm of the two sexes was not constant over time and changed during the light period. There was also an effect of density on locomotor activity, where males at intermediate densities showed higher activity. Further, the predictability of the locomotor activity, estimated as the degree of autocorrelation of the activity data, increased with the number of males present in the vials both with and without the presence of females. Overall, this study demonstrates that locomotor activity in M. domestica is affected by sex—ratio and density. Furthermore, the predictability of locomotor activity is affected by both sex—ratio, density, and circadian rhythm. These results add to our understanding of the behavioral interactions between houseflies and highlight the importance of these factors when designing behavioral experiments using M. domestica.

  10. Effective pathfinding for four-wheeled robot based on combining Theta* and hybrid A* algorithms

    Directory of Open Access Journals (Sweden)

    Віталій Геннадійович Михалько

    2016-07-01

    Full Text Available Effective pathfinding algorithm based on Theta* and Hybrid A* algorithms was developed for four-wheeled robot. Pseudocode for algorithm was showed and explained. Algorithm and simulator for four-wheeled robot were implemented using Java programming language. Algorithm was tested on U-obstacles, complex maps and for parking problem

  11. N-Bit Binary Resistor

    Science.gov (United States)

    Tcheng, Ping

    1989-01-01

    Binary resistors in series tailored to precise value of resistance. Desired value of resistance obtained by cutting appropriate traces across resistors. Multibit, binary-based, adjustable resistor with high resolution used in many applications where precise resistance required.

  12. Study of flow and loss processes at the ends of a linear theta pinch. Progress report, June 1, 1977--May 31, 1978

    International Nuclear Information System (INIS)

    York, T.M.; Klevans, E.H.

    1978-02-01

    Experimental and analytical studies of end loss from a theta pinch have been carried out. Detailed diagnostic studies of a 25 cm long theta pinch operating with reversed trapped fields have been completed; spectroscopic studies, magnetic probe, pressure probe, double diamagnetic loop, luminosity studies and Thomson scattering studies of the plasma have been carried out over the 8 μsec duration of the transient loss. Two new diagnostic techniques have been developed based on the available Thomson scattering laser source. A study of plasma loss from a 10.5 long theta pinch with an axial Twyman-Green interferometer has been completed and reported. The basic studies needed for subsequent experimental work on heat conduction loss being diagnosed by Thomson scattering data in the end region, with and without mirror coil, has been completed as a part of the mirror field studies

  13. Some properties of spectral binary stars

    International Nuclear Information System (INIS)

    Krajcheva, Z.T.; Popova, E.I.; Tutukov, A.V.; Yungel'son, L.R.; AN SSSR, Moscow. Astronomicheskij Sovet)

    1978-01-01

    Statistical investigations of spectra binary stars are carried out. Binary systems consisting of main sequence stars are considered. For 826 binary stars masses of components, ratios of component masses, semiaxes of orbits and orbital angular momenta are calculated. The distributions of these parameters and their correlations are analyzed. The dependences of statistical properties of spectral binary stars on their origin and evolution are discussed

  14. (No) time for control: Frontal theta dynamics reveal the cost of temporally guided conflict anticipation.

    Science.gov (United States)

    van Driel, Joram; Swart, Jennifer C; Egner, Tobias; Ridderinkhof, K Richard; Cohen, Michael X

    2015-12-01

    During situations of response conflict, cognitive control is characterized by prefrontal theta-band (3- to 8-Hz) activity. It has been shown that cognitive control can be triggered proactively by contextual cues that predict conflict. Here, we investigated whether a pretrial preparation interval could serve as such a cue. This would show that the temporal contingencies embedded in the task can be used to anticipate upcoming conflict. To this end, we recorded electroencephalography (EEG) from 30 human subjects while they performed a version of a Simon task in which the duration of a fixation cross between trials predicted whether the next trial would contain response conflict. Both their behavior and EEG activity showed a consistent but unexpected pattern of results: The conflict effect (increased reaction times and decreased accuracy on conflict as compared to nonconflict trials) was stronger when conflict was cued, and this was associated with stronger conflict-related midfrontal theta activity and functional connectivity. Interestingly, intervals that predicted conflict did show a pretarget increase in midfrontal theta power. These findings suggest that temporally guided expectations of conflict do heighten conflict anticipation, but also lead to less efficiently applied reactive control. We further explored this post-hoc interpretation by means of three behavioral follow-up experiments, in which we used nontemporal cues, semantically informative cues, and neutral cues. Together, this body of results suggests that the counterintuitive cost of conflict cueing may not be uniquely related to the temporal domain, but may instead be related to the implicitness and validity of the cue.

  15. Resting-state theta band connectivity and graph analysis in generalized social anxiety disorder

    Directory of Open Access Journals (Sweden)

    Mengqi Xing

    2017-01-01

    Conclusions: Theta-dependent interconnectivity was associated with state anxiety in gSAD and an increase in information processing efficiency in gSAD (compared to controls. Results may represent enhanced baseline self-focused attention, which is consistent with cognitive models of gSAD and fMRI studies implicating emotion dysregulation and disturbances in task negative networks (e.g., default mode network in gSAD.

  16. Microlensing Binaries Discovered through High-magnification Channel

    DEFF Research Database (Denmark)

    Shin, I.-G.; Choi, J.-Y.; Park, S.-Y.

    2012-01-01

    Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of eight binary-lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010. The perturba......Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of eight binary-lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010...

  17. Slow cortical potential and theta/beta neurofeedback training in adults: effects on attentional processes, and motor system excitability

    Directory of Open Access Journals (Sweden)

    Petra eStuder

    2014-07-01

    Full Text Available Neurofeedback (NF is being successfully applied, among others, in children with ADHD and as a peak performance training in healthy subjects. However, the neuronal mechanisms mediating a successful NF training have not yet been sufficiently uncovered for both theta/beta (T/B, and slow cortical potential (SCP training, two protocols established in NF in ADHD. In the present randomized controlled investigation in adults without a clinical diagnosis (n = 59, the specificity of the effects of these two NF protocols on attentional processes, and motor system excitability were to be examined, focusing on the underlying neuronal mechanisms. NF training consisted of 10 double sessions, and self-regulation skills were analyzed. Pre- and post-training assessments encompassed performance and event-related potential measures during an attention task, and motor system excitability assessed by transcranial magnetic stimulation. Some NF protocol specific effects have been obtained. However, due to the limited sample size medium effects didn’t reach the level of significance. Self-regulation abilities during negativity trials of the SCP training were associated with increased contingent negative variation amplitudes, indicating improved resource allocation during cognitive preparation. Theta/beta training was associated with increased response speed and decreased target-P3 amplitudes after successful theta/beta regulation suggested reduced attentional resources necessary for stimulus evaluation. Motor system excitability effects after theta/beta training paralleled the effects of methylphenidate. Overall, our results are limited by the non-sufficiently acquired self-regulation skills, but some specific effects between good and poor learners could be described. Future studies with larger sample sizes and sufficient acquisition of self-regulation skills are needed to further evaluate the protocol specific effects on attention and motor system excitability

  18. Performance analysis and binary working fluid selection of combined flash-binary geothermal cycle

    International Nuclear Information System (INIS)

    Zeyghami, Mehdi

    2015-01-01

    Performance of the combined flash-binary geothermal power cycle for geofluid temperatures between 150 and 250 °C is studied. A thermodynamic model is developed, and the suitable binary working fluids for different geofluid temperatures are identified from a list of thirty working fluid candidates, consisting environmental friendly refrigerants and hydrocarbons. The overall system exergy destruction and Vapor Expansion Ratio across the binary cycle turbine are selected as key performance indicators. The results show that for low-temperature heat sources using refrigerants as binary working fluids result in higher overall cycle efficiency and for medium and high-temperature resources, hydrocarbons are more suitable. For combined flash-binary cycle, secondary working fluids; R-152a, Butane and Cis-butane show the best performances at geofluid temperatures 150, 200 and 250 °C respectively. The overall second law efficiency is calculated as high as 0.48, 0.55 and 0.58 for geofluid temperatures equal 150, 200 and 250 °C respectively. The flash separator pressure found to has important effects on cycle operation and performance. Separator pressure dictates the work production share of steam and binary parts of the system. And there is an optimal separator pressure at which overall exergy destruction of the cycle achieves its minimum value. - Highlights: • Performance of the combined flash-binary geothermal cycle is investigated. • Thirty different fluids are screened to find the most suitable ORC working fluid. • Optimum cycle operation conditions presented for geofluids between 150 °C and 250 °C. • Refrigerants are more suitable for the ORC at geothermal sources temperature ≤200 °C. • Hydrocarbons are more suitable for the ORC at geothermal sources temperature >200 °C

  19. BINARY CEPHEIDS: SEPARATIONS AND MASS RATIOS IN 5 M {sub ☉} BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Nancy Remage; Karovska, Margarita; Tingle, Evan [Smithsonian Astrophysical Observatory, MS 4, 60 Garden Street, Cambridge, MA 02138 (United States); Bond, Howard E. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Schaefer, Gail H. [The CHARA Array, Georgia State University, P.O. Box 3965, Atlanta, GA 30302-3965 (United States); Mason, Brian D., E-mail: nevans@cfa.harvard.edu, E-mail: heb11@psu.edu, E-mail: schaefer@chara-array.org [US Naval Observatory, 3450 Massachusetts Avenue, NW, Washington, DC 20392-5420 (United States)

    2013-10-01

    Deriving the distribution of binary parameters for a particular class of stars over the full range of orbital separations usually requires the combination of results from many different observing techniques (radial velocities, interferometry, astrometry, photometry, direct imaging), each with selection biases. However, Cepheids—cool, evolved stars of ∼5 M {sub ☉}—are a special case because ultraviolet (UV) spectra will immediately reveal any companion star hotter than early type A, regardless of the orbital separation. We have used International Ultraviolet Explorer UV spectra of a complete sample of all 76 Cepheids brighter than V = 8 to create a list of all 18 Cepheids with companions more massive than 2.0 M {sub ☉}. Orbital periods of many of these binaries are available from radial-velocity studies, or can be estimated for longer-period systems from detected velocity variability. In an imaging survey with the Hubble Space Telescope Wide Field Camera 3, we resolved three of the companions (those of η Aql, S Nor, and V659 Cen), allowing us to make estimates of the periods out to the long-period end of the distribution. Combining these separations with orbital data in the literature, we derive an unbiased distribution of binary separations, orbital periods, and mass ratios. The distribution of orbital periods shows that the 5 M {sub ☉} binaries have systematically shorter periods than do 1 M {sub ☉} stars. Our data also suggest that the distribution of mass ratios depends on both binary separation and system multiplicity. The distribution of mass ratios as a function of orbital separation, however, does not depend on whether a system is a binary or a triple.

  20. Dissipative binary collisions

    International Nuclear Information System (INIS)

    Aboufirassi, M; Angelique, J.C.; Bizard, G.; Bougault, R.; Brou, R.; Buta, A.; Colin, J.; Cussol, D.; Durand, D.; Genoux-Lubain, A.; Horn, D.; Kerambrun, A.; Laville, J.L.; Le Brun, C.; Lecolley, J.F.; Lefebvres, F.; Lopez, O.; Louvel, M.; Meslin, C.; Metivier, V.; Nakagawa, T.; Peter, J.; Popescu, R.; Regimbart, R.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Wieloch, A.; Yuasa-Nakagawa, K.

    1998-01-01

    The binary character of the heavy ion collisions at intermediate energies in the exit channel has been observed under 30 MeV/n in medium and heavy systems. Measurements in light systems at energies approaching ∼ 100 MeV/nucleon as well as in very heavy systems have allowed to extend considerably the investigations of this binary process. Thus, the study of the Pb + Au system showed that the complete charge events indicated two distinct sources: the quasi-projectile and the quasi-target. The characteristics of these two sources are rather well reproduced by a trajectory computation which takes into account the Coulomb and nuclear forces and the friction appearing from the projectile-target interaction. The Wilczynski diagram is used to probe the correlation between the kinetic energy quenching and the deflecting angle. In case of the system Pb + Au at 29 MeV/nucleon the diagram indicate dissipative binary collisions typical for low energies. This binary aspect was also detected in the systems Xe + Ag at 44 MeV/nucleon, 36 Ar + 27 Al and 64 Zn + nat Ti. Thus, it was possible to reconstruct the quasi-projectile and to study its mass and excitation energy evolution as a function of the impact parameter. The dissipative binary collisions represent for the systems and energies under considerations the main contribution to the cross section. This does not implies that there are not other processes; particularly, the more or less complete fusion is also observed but with a low cross section which decreases with the increase of bombardment energy. More exclusive measurements with the INDRA detector on quasi-symmetric systems as Ar + KCl and Xe + Sn seem to confirm the importance of the binary collisions. The two source reconstruction of the Xe + Sn data at 50 MeV/nucleon reproduces the same behaviour as that observed in the system Pb + Au at 29 MeV/nucleon

  1. Contact Binaries on Their Way Towards Merging

    Science.gov (United States)

    Gazeas, K.

    2015-07-01

    Contact binaries are the most frequently observed type of eclipsing star system. They are small, cool, low-mass binaries belonging to a relatively old stellar population. They follow certain empirical relationships that closely connect a number of physical parameters with each other, largely because of constraints coming from the Roche geometry. As a result, contact binaries provide an excellent test of stellar evolution, specifically for stellar merger scenarios. Observing campaigns by many authors have led to the cataloging of thousands of contact binaries and enabled statistical studies of many of their properties. A large number of contact binaries have been found to exhibit extraordinary behavior, requiring follow-up observations to study their peculiarities in detail. For example, a doubly-eclipsing quadruple system consisting of a contact binary and a detached binary is a highly constrained system offering an excellent laboratory to test evolutionary theories for binaries. A new observing project was initiated at the University of Athens in 2012 in order to investigate the possible lower limit for the orbital period of binary systems before coalescence, prior to merging.

  2. Index of Theta/Alpha Ratio of the Quantitative Electroencephalogram in Alzheimer's Disease: A Case-Control Study.

    Science.gov (United States)

    Fahimi, Golshan; Tabatabaei, Seyed Mahmoud; Fahimi, Elnaz; Rajebi, Hamid

    2017-08-01

    Alzheimer's disease (AD) is a devastating neurodegenerative disorder in human beings associated with cognitive, behavioral and motor impairments. The main symptom of AD is dementia, which causes difficulties in carrying out daily practices. Brain waves are altered in people with AD. Relative indices of brain waves can be beneficial in the diagnosis of AD. In this case-control study, 50 patients with AD and 50 matched healthy individuals were enrolled in case and control groups respectively. With recording and analyzing of brain waves with the utilization of quantitative electroencephalogram (QEEG), index of theta/alpha ratio was assessed in both groups. The index of theta/alpha ratio was significantly higher in patients with AD in comparison to healthy individuals (Pratio obtained by QEEG provides a non-invasive diagnostic marker of AD, which may be helpful in identification of non-advanced disease in susceptible individuals.

  3. Permutation Entropy for Random Binary Sequences

    Directory of Open Access Journals (Sweden)

    Lingfeng Liu

    2015-12-01

    Full Text Available In this paper, we generalize the permutation entropy (PE measure to binary sequences, which is based on Shannon’s entropy, and theoretically analyze this measure for random binary sequences. We deduce the theoretical value of PE for random binary sequences, which can be used to measure the randomness of binary sequences. We also reveal the relationship between this PE measure with other randomness measures, such as Shannon’s entropy and Lempel–Ziv complexity. The results show that PE is consistent with these two measures. Furthermore, we use PE as one of the randomness measures to evaluate the randomness of chaotic binary sequences.

  4. Computer simulation of a staging system for a theta-pinch reactor (RTPR)

    International Nuclear Information System (INIS)

    Crnkovich, P.G.

    1976-02-01

    To reduce excessive energy requirements for the implosion heating system of a theta-pinch reactor, two staging methods, the brute force and bucking field options, were proposed. A Marshall coil and a segmented coil were also considered. Calculations involved in coding these coil designs and staging options into a PL/I subprogram are described. A marked savings in the energy required for the IH system is realized with the bucking option and others

  5. Dynamical stability of the alpha and theta phases of alumina

    DEFF Research Database (Denmark)

    Lodziana, Zbigniew; Parlinski, K.

    2003-01-01

    Using density functional calculations the phonon dispersion relations, phonon density of states, and free energy of theta and alpha phases of alumina are investigated. The temperature dependence of the free energy indicates that entropy contributes to the destabilization of the alpha phase...... cations in alumina, and suggest that some other than entropic mechanism exists, which stabilizes transition aluminas up to 1400 K. The present calculations go beyond the ground state energy calculations [C. Wolverton and K.C. Hass, Phys. Rev. B 63, 24102 (2001)], and give an additional understanding...... of the stability of transition alumina at finite temperatures....

  6. Completely X-symmetric S-matrices corresponding to theta functions and models of statistical mechanics

    International Nuclear Information System (INIS)

    Chudnovsky, D.V.; Chudnovsky, G.V.

    1981-01-01

    We consider general expressions of factorized S-matrices with Abelian symmetry expressed in terms of theta-functions. These expressions arise from representations of the Heisenberg group. New examples of factorized S-matrices lead to a large class of completely integrable models of statistical mechanics which generalize the XYZ-model of the eight-vertex model. (orig.)

  7. Electron temperature in field reversed configurations and theta pinches with closed magnetic field lines

    International Nuclear Information System (INIS)

    Newton, A.A.

    1986-01-01

    Field-reversed configurations (FRC) and theta pinches with trapped reversed bias field are essentially the same magnetic confinement systems using closed magnetic field lines inside an open-ended magnetic flux tube. A simple model of joule heating and parallel electron thermal conduction along the open flux lines to an external heat sink gives the electron temperature as Tsub(e)(eV) approx.= 0.05 Bsup(2/3)(G)Lsup(1/3)(cm), where B is the magnetic field and L is the coil length. This model appears to agree with measurements from present FRC experiments and past theta-pinch experiments which cover a range of 40-900 eV. The energy balance in the model is dominated by (a) parallel electron thermal conduction along the open field lines which has a steep temperature dependence, Q is proportional to Tsub(e)sup(7/2), and (b) the assumed rapid perpendicular transport in the plasma bulk which, in experiments to date, may be due to the small number of ion gyroradii across the plasma. (author)

  8. Binary Systems and the Initial Mass Function

    Science.gov (United States)

    Malkov, O. Yu.

    2017-07-01

    In the present paper we discuss advantages and disadvantages of binary stars, which are important for star formation history determination. We show that to make definite conclusions of the initial mass function shape, it is necessary to study binary population well enough to correct the luminosity function for unresolved binaries; to construct the mass-luminosity relation based on wide binaries data, and to separate observational mass functions of primaries, of secondaries, and of unresolved binaries.

  9. Accuracy of binary black hole waveform models for aligned-spin binaries

    Science.gov (United States)

    Kumar, Prayush; Chu, Tony; Fong, Heather; Pfeiffer, Harald P.; Boyle, Michael; Hemberger, Daniel A.; Kidder, Lawrence E.; Scheel, Mark A.; Szilagyi, Bela

    2016-05-01

    Coalescing binary black holes are among the primary science targets for second generation ground-based gravitational wave detectors. Reliable gravitational waveform models are central to detection of such systems and subsequent parameter estimation. This paper performs a comprehensive analysis of the accuracy of recent waveform models for binary black holes with aligned spins, utilizing a new set of 84 high-accuracy numerical relativity simulations. Our analysis covers comparable mass binaries (mass-ratio 1 ≤q ≤3 ), and samples independently both black hole spins up to a dimensionless spin magnitude of 0.9 for equal-mass binaries and 0.85 for unequal mass binaries. Furthermore, we focus on the high-mass regime (total mass ≳50 M⊙ ). The two most recent waveform models considered (PhenomD and SEOBNRv2) both perform very well for signal detection, losing less than 0.5% of the recoverable signal-to-noise ratio ρ , except that SEOBNRv2's efficiency drops slightly for both black hole spins aligned at large magnitude. For parameter estimation, modeling inaccuracies of the SEOBNRv2 model are found to be smaller than systematic uncertainties for moderately strong GW events up to roughly ρ ≲15 . PhenomD's modeling errors are found to be smaller than SEOBNRv2's, and are generally irrelevant for ρ ≲20 . Both models' accuracy deteriorates with increased mass ratio, and when at least one black hole spin is large and aligned. The SEOBNRv2 model shows a pronounced disagreement with the numerical relativity simulation in the merger phase, for unequal masses and simultaneously both black hole spins very large and aligned. Two older waveform models (PhenomC and SEOBNRv1) are found to be distinctly less accurate than the more recent PhenomD and SEOBNRv2 models. Finally, we quantify the bias expected from all four waveform models during parameter estimation for several recovered binary parameters: chirp mass, mass ratio, and effective spin.

  10. Radial Velocities of 41 Kepler Eclipsing Binaries

    Science.gov (United States)

    Matson, Rachel A.; Gies, Douglas R.; Guo, Zhao; Williams, Stephen J.

    2017-12-01

    Eclipsing binaries are vital for directly determining stellar parameters without reliance on models or scaling relations. Spectroscopically derived parameters of detached and semi-detached binaries allow us to determine component masses that can inform theories of stellar and binary evolution. Here we present moderate resolution ground-based spectra of stars in close binary systems with and without (detected) tertiary companions observed by NASA’s Kepler mission and analyzed for eclipse timing variations. We obtain radial velocities and spectroscopic orbits for five single-lined and 35 double-lined systems, and confirm one false positive eclipsing binary. For the double-lined spectroscopic binaries, we also determine individual component masses and examine the mass ratio {M}2/{M}1 distribution, which is dominated by binaries with like-mass pairs and semi-detached classical Algol systems that have undergone mass transfer. Finally, we constrain the mass of the tertiary component for five double-lined binaries with previously detected companions.

  11. Planets in Binary Star Systems

    CERN Document Server

    Haghighipour, Nader

    2010-01-01

    The discovery of extrasolar planets over the past decade has had major impacts on our understanding of the formation and dynamical evolution of planetary systems. There are features and characteristics unseen in our solar system and unexplainable by the current theories of planet formation and dynamics. Among these new surprises is the discovery of planets in binary and multiple-star systems. The discovery of such "binary-planetary" systems has confronted astrodynamicists with many new challenges, and has led them to re-examine the theories of planet formation and dynamics. Among these challenges are: How are planets formed in binary star systems? What would be the notion of habitability in such systems? Under what conditions can binary star systems have habitable planets? How will volatiles necessary for life appear on such planets? This volume seeks to gather the current research in the area of planets in binary and multistar systems and to familiarize readers with its associated theoretical and observation...

  12. Biological trait analysis and stability of lambda-cyhalothrin resistance in the house fly, Musca domestica L. (Diptera: Muscidae).

    Science.gov (United States)

    Abbas, Naeem; Shah, Rizwan Mustafa; Shad, Sarfraz Ali; Iqbal, Naeem; Razaq, Muhammad

    2016-05-01

    House flies, Musca domestica L., (Diptera: Muscidae), are pests of poultry and have the ability to develop resistance to insecticides. To design a strategy for resistance management, life history traits based on laboratory observations were established for lambda-cyhalothrin-resistant, susceptible and reciprocal crosses of M. domestica strains. Bioassay results showed that the lambda-cyhalothrin-selected strain developed a resistance ratio of 98.34 compared to its susceptible strain. The lambda-cyhalothrin-selected strain had a relative fitness of 0.26 and lower fecundity, hatchability, lower number of next generation larvae, and net reproductive rate compared with its susceptible strain. Mean population growth rates, such as intrinsic rate of population increase, and biotic potential were lower for the lambda-cyhalothrin-selected strain compared to its susceptible strain. Resistance to lambda-cyhalothrin, indoxacarb, and abamectin was unstable while resistance to bifenthrin and methomyl was stable in the lambda-cyhalothrin-selected strain of M. domestica. Development of resistance can cost considerable fitness for the lambda-cyhalothrin-selected strain. The present study provided useful information for making potential management strategies to delay resistance development in M. domestica.

  13. Theoretical studies of binaries in astrophysics

    Science.gov (United States)

    Dischler, Johann Sebastian

    This thesis introduces and summarizes four papers dealing with computer simulations of astrophysical processes involving binaries. The first part gives the rational and theoretical background to these papers. In paper I and II a statistical approach to studying eclipsing binaries is described. By using population synthesis models for binaries the probabilities for eclipses are calculated for different luminosity classes of binaries. These are compared with Hipparcos data and they agree well if one uses a standard input distribution for the orbit sizes. If one uses a random pairing model, where both companions are independently picked from an IMF, one finds too feclipsing binaries by an order of magnitude. In paper III we investigate a possible scenario for the origin of the stars observed close to the centre of our galaxy, called S stars. We propose that a cluster falls radially cowards the central black hole. The binaries within the cluster can then, if they have small impact parameters, be broken up by the black hole's tidal held and one of the components of the binary will be captured by the black hole. Paper IV investigates how the onset of mass transfer in eccentric binaries depends on the eccentricity. To do this we have developed a new two-phase SPH scheme where very light particles are at tire outer edge of our simulated star. This enables us to get a much better resolution of the very small mass that is transferred in close binaries. Our simulations show that the minimum required distance between the stars to have mass transfer decreases with the eccentricity.

  14. Mining frequent binary expressions

    NARCIS (Netherlands)

    Calders, T.; Paredaens, J.; Kambayashi, Y.; Mohania, M.K.; Tjoa, A.M.

    2000-01-01

    In data mining, searching for frequent patterns is a common basic operation. It forms the basis of many interesting decision support processes. In this paper we present a new type of patterns, binary expressions. Based on the properties of a specified binary test, such as reflexivity, transitivity

  15. Survival of planets around shrinking stellar binaries.

    Science.gov (United States)

    Muñoz, Diego J; Lai, Dong

    2015-07-28

    The discovery of transiting circumbinary planets by the Kepler mission suggests that planets can form efficiently around binary stars. None of the stellar binaries currently known to host planets has a period shorter than 7 d, despite the large number of eclipsing binaries found in the Kepler target list with periods shorter than a few days. These compact binaries are believed to have evolved from wider orbits into their current configurations via the so-called Lidov-Kozai migration mechanism, in which gravitational perturbations from a distant tertiary companion induce large-amplitude eccentricity oscillations in the binary, followed by orbital decay and circularization due to tidal dissipation in the stars. Here we explore the orbital evolution of planets around binaries undergoing orbital decay by this mechanism. We show that planets may survive and become misaligned from their host binary, or may develop erratic behavior in eccentricity, resulting in their consumption by the stars or ejection from the system as the binary decays. Our results suggest that circumbinary planets around compact binaries could still exist, and we offer predictions as to what their orbital configurations should be like.

  16. Close-binary central stars of planetary nebulae

    International Nuclear Information System (INIS)

    Bond, H.E.; Grauer, A.D.

    1987-01-01

    Recent observations of PN central stars identified as binary systems are reviewed. The theoretical significance of binary central stars is discussed, and the characteristics of UU Sge, V 477 Lyr, MT Ser, LSS 2018, VW Pyx, and the central star of HFG 1 are briefly summarized. All of these binaries are shown to have periods less than 1 day, and it is estimated that about 10 percent of all binary central stars are close binaries. 27 references

  17. Bondi-Hoyle-Lyttleton Accretion onto Binaries

    Science.gov (United States)

    Antoni, Andrea; MacLeod, Morgan; Ramírez-Ruiz, Enrico

    2018-01-01

    Binary stars are not rare. While only close binary stars will eventually interact with one another, even the widest binary systems interact with their gaseous surroundings. The rates of accretion and the gaseous drag forces arising in these interactions are the key to understanding how these systems evolve. This poster examines accretion flows around a binary system moving supersonically through a background gas. We perform three-dimensional hydrodynamic simulations of Bondi-Hoyle-Lyttleton accretion using the adaptive mesh refinement code FLASH. We simulate a range of values of semi-major axis of the orbit relative to the gravitational focusing impact parameter of the pair. On large scales, gas is gravitationally focused by the center-of-mass of the binary, leading to dynamical friction drag and to the accretion of mass and momentum. On smaller scales, the orbital motion imprints itself on the gas. Notably, the magnitude and direction of the forces acting on the binary inherit this orbital dependence. The long-term evolution of the binary is determined by the timescales for accretion, slow down of the center-of-mass, and decay of the orbit. We use our simulations to measure these timescales and to establish a hierarchy between them. In general, our simulations indicate that binaries moving through gaseous media will slow down before the orbit decays.

  18. Formation and Evolution of X-ray Binaries

    Science.gov (United States)

    Shao, Y.

    2017-07-01

    X-ray binaries are a class of binary systems, in which the accretor is a compact star (i.e., black hole, neutron star, or white dwarf). They are one of the most important objects in the universe, which can be used to study not only binary evolution but also accretion disks and compact stars. Statistical investigations of these binaries help to understand the formation and evolution of galaxies, and sometimes provide useful constraints on the cosmological models. The goal of this thesis is to investigate the formation and evolution processes of X-ray binaries including Be/X-ray binaries, low-mass X-ray binaries (LMXBs), ultraluminous X-ray sources (ULXs), and cataclysmic variables. In Chapter 1 we give a brief review on the basic knowledge of the binary evolution. In Chapter 2 we discuss the formation of Be stars through binary interaction. In this chapter we investigate the formation of Be stars resulting from mass transfer in binaries in the Galaxy. Using binary evolution and population synthesis calculations, we find that in Be/neutron star binaries the Be stars have a lower limit of mass ˜ 8 M⊙ if they are formed by a stable (i.e., without the occurrence of common envelope evolution) and nonconservative mass transfer. We demonstrate that the isolated Be stars may originate from both mergers of two main-sequence stars and disrupted Be binaries during the supernova explosions of the primary stars, but mergers seem to play a much more important role. Finally the fraction of Be stars produced by binary interactions in all B type stars can be as high as ˜ 13%-30% , implying that most of Be stars may result from binary interaction. In Chapter 3 we show the evolution of intermediate- and low-mass X-ray binaries (I/LMXBs) and the formation of millisecond pulsars. Comparing the calculated results with the observations of binary radio pulsars, we report the following results: (1) The allowed parameter space for forming binary pulsars in the initial orbital period

  19. Modelling binary data

    CERN Document Server

    Collett, David

    2002-01-01

    INTRODUCTION Some Examples The Scope of this Book Use of Statistical Software STATISTICAL INFERENCE FOR BINARY DATA The Binomial Distribution Inference about the Success Probability Comparison of Two Proportions Comparison of Two or More Proportions MODELS FOR BINARY AND BINOMIAL DATA Statistical Modelling Linear Models Methods of Estimation Fitting Linear Models to Binomial Data Models for Binomial Response Data The Linear Logistic Model Fitting the Linear Logistic Model to Binomial Data Goodness of Fit of a Linear Logistic Model Comparing Linear Logistic Models Linear Trend in Proportions Comparing Stimulus-Response Relationships Non-Convergence and Overfitting Some other Goodness of Fit Statistics Strategy for Model Selection Predicting a Binary Response Probability BIOASSAY AND SOME OTHER APPLICATIONS The Tolerance Distribution Estimating an Effective Dose Relative Potency Natural Response Non-Linear Logistic Regression Models Applications of the Complementary Log-Log Model MODEL CHECKING Definition of Re...

  20. Effects of semantic relatedness on age-related associative memory deficits: the role of theta oscillations.

    Science.gov (United States)

    Crespo-Garcia, Maite; Cantero, Jose L; Atienza, Mercedes

    2012-07-16

    Growing evidence suggests that age-related deficits in associative memory are alleviated when the to-be-associated items are semantically related. Here we investigate whether this beneficial effect of semantic relatedness is paralleled by spatio-temporal changes in cortical EEG dynamics during incidental encoding. Young and older adults were presented with faces at a particular spatial location preceded by a biographical cue that was either semantically related or unrelated. As expected, automatic encoding of face-location associations benefited from semantic relatedness in the two groups of age. This effect correlated with increased power of theta oscillations over medial and anterior lateral regions of the prefrontal cortex (PFC) and lateral regions of the posterior parietal cortex (PPC) in both groups. But better-performing elders also showed increased brain-behavior correlation in the theta band over the right inferior frontal gyrus (IFG) as compared to young adults. Semantic relatedness was, however, insufficient to fully eliminate age-related differences in associative memory. In line with this finding, poorer-performing elders relative to young adults showed significant reductions of theta power in the left IFG that were further predictive of behavioral impairment in the recognition task. All together, these results suggest that older adults benefit less than young adults from executive processes during encoding mainly due to neural inefficiency over regions of the left ventrolateral prefrontal cortex (VLPFC). But this associative deficit may be partially compensated for by engaging preexistent semantic knowledge, which likely leads to an efficient recruitment of attentional and integration processes supported by the left PPC and left anterior PFC respectively, together with neural compensatory mechanisms governed by the right VLPFC. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Formation and evolution of compact binaries

    NARCIS (Netherlands)

    Sluijs, Marcel Vincent van der

    2006-01-01

    In this thesis we investigate the formation and evolution of compact binaries. Chapters 2 through 4 deal with the formation of luminous, ultra-compact X-ray binaries in globular clusters. We show that the proposed scenario of magnetic capture produces too few ultra-compact X-ray binaries to explain

  2. Do stellar clusters form fewer binaries? Using moderate separation binaries to distinguish between nature and nurture

    Science.gov (United States)

    Reiter, Megan

    2017-08-01

    Fewer wide-separation binaries are found in dense stellar clusters than in looser stellar associations. It is therefore unclear whether feedback in clusters prevents the formation of multiple systems or dynamical interactions destroy them. Measuring the prevalence of close, bound binary systems provide a key test to distinguish between these possibilities. Systems with separations of 10-50 AU will survive interactions in the cluster environment, and therefore are more representative of the natal population of multiple systems. By fitting a double-star PSF, we will identify visual binaries in the Orion Nebula with separations as small as 0.03. At the distance of Orion, this corresponds to a physical separation of 12 AU, effectively closing the observational gap in the binary separation distribution left between known visual and spectroscopic binaries (>65 AU or PhD thesis.

  3. Origin of very-short orbital-period binary systems

    International Nuclear Information System (INIS)

    Miyaji, S.

    1983-01-01

    Recent observations of four close binaries have established that there is a group of very-short orbital-period (VSOP) binaries whose orbital periods are less than 60 minutes. The VSOP binaries consist of both X-ray close binaries and cataclysmic variables. Their orbital periods are too short to have a main-sequence companion. However, four binaries, none of which belongs to any globular cluster, are too abundant to be explained by the capturing mechanism of a white dwarf. Therefore it seemed to be worthwhile to present an evolutionary scenario from an original binary system which can be applied for all VSOP binaries. (Auth.)

  4. Separation in 5 Msun Binaries

    Science.gov (United States)

    Evans, Nancy R.; Bond, H. E.; Schaefer, G.; Mason, B. D.; Karovska, M.; Tingle, E.

    2013-01-01

    Cepheids (5 Msun stars) provide an excellent sample for determining the binary properties of fairly massive stars. International Ultraviolet Explorer (IUE) observations of Cepheids brighter than 8th magnitude resulted in a list of ALL companions more massive than 2.0 Msun uniformly sensitive to all separations. Hubble Space Telescope Wide Field Camera 3 (WFC3) has resolved three of these binaries (Eta Aql, S Nor, and V659 Cen). Combining these separations with orbital data in the literature, we derive an unbiased distribution of binary separations for a sample of 18 Cepheids, and also a distribution of mass ratios. The distribution of orbital periods shows that the 5 Msun binaries prefer shorter periods than 1 Msun stars, reflecting differences in star formation processes.

  5. Astronomy of binary and multiple stars

    International Nuclear Information System (INIS)

    Tokovinin, A.A.

    1984-01-01

    Various types of binary stars and methods for their observation are described in a popular form. Some models of formation and evolution of binary and multiple star systems are presented. It is concluded that formation of binary and multiple stars is a regular stage in the process of star production

  6. A ROSAT Survey of Contact Binary Stars

    Science.gov (United States)

    Geske, M. T.; Gettel, S. J.; McKay, T. A.

    2006-01-01

    Contact binary stars are common variable stars that are all believed to emit relatively large fluxes of X-rays. In this work we combine a large new sample of contact binary stars derived from the ROTSE-I telescope with X-ray data from the ROSAT All Sky Survey (RASS) to estimate the X-ray volume emissivity of contact binary stars in the Galaxy. We obtained X-ray fluxes for 140 contact binaries from the RASS, as well as two additional stars observed by the XMM-Newton observatory. From these data we confirm the emission of X-rays from all contact binary systems, with typical luminosities of approximately 1.0×1030 ergs s-1. Combining calculated luminosities with an estimated contact binary space density, we find that contact binaries do not have strong enough X-ray emission to account for a significant portion of the Galactic X-ray background.

  7. GALAXY ROTATION AND RAPID SUPERMASSIVE BINARY COALESCENCE

    Energy Technology Data Exchange (ETDEWEB)

    Holley-Bockelmann, Kelly [Vanderbilt University, Nashville, TN (United States); Khan, Fazeel Mahmood, E-mail: k.holley@vanderbilt.edu [Institute of Space Technology (IST), Islamabad (Pakistan)

    2015-09-10

    Galaxy mergers usher the supermassive black hole (SMBH) in each galaxy to the center of the potential, where they form an SMBH binary. The binary orbit shrinks by ejecting stars via three-body scattering, but ample work has shown that in spherical galaxy models, the binary separation stalls after ejecting all the stars in its loss cone—this is the well-known final parsec problem. However, it has been shown that SMBH binaries in non-spherical galactic nuclei harden at a nearly constant rate until reaching the gravitational wave regime. Here we use a suite of direct N-body simulations to follow SMBH binary evolution in both corotating and counterrotating flattened galaxy models. For N > 500 K, we find that the evolution of the SMBH binary is convergent and is independent of the particle number. Rotation in general increases the hardening rate of SMBH binaries even more effectively than galaxy geometry alone. SMBH binary hardening rates are similar for co- and counterrotating galaxies. In the corotating case, the center of mass of the SMBH binary settles into an orbit that is in corotation resonance with the background rotating model, and the coalescence time is roughly a few 100 Myr faster than a non-rotating flattened model. We find that counterrotation drives SMBHs to coalesce on a nearly radial orbit promptly after forming a hard binary. We discuss the implications for gravitational wave astronomy, hypervelocity star production, and the effect on the structure of the host galaxy.

  8. GALAXY ROTATION AND RAPID SUPERMASSIVE BINARY COALESCENCE

    International Nuclear Information System (INIS)

    Holley-Bockelmann, Kelly; Khan, Fazeel Mahmood

    2015-01-01

    Galaxy mergers usher the supermassive black hole (SMBH) in each galaxy to the center of the potential, where they form an SMBH binary. The binary orbit shrinks by ejecting stars via three-body scattering, but ample work has shown that in spherical galaxy models, the binary separation stalls after ejecting all the stars in its loss cone—this is the well-known final parsec problem. However, it has been shown that SMBH binaries in non-spherical galactic nuclei harden at a nearly constant rate until reaching the gravitational wave regime. Here we use a suite of direct N-body simulations to follow SMBH binary evolution in both corotating and counterrotating flattened galaxy models. For N > 500 K, we find that the evolution of the SMBH binary is convergent and is independent of the particle number. Rotation in general increases the hardening rate of SMBH binaries even more effectively than galaxy geometry alone. SMBH binary hardening rates are similar for co- and counterrotating galaxies. In the corotating case, the center of mass of the SMBH binary settles into an orbit that is in corotation resonance with the background rotating model, and the coalescence time is roughly a few 100 Myr faster than a non-rotating flattened model. We find that counterrotation drives SMBHs to coalesce on a nearly radial orbit promptly after forming a hard binary. We discuss the implications for gravitational wave astronomy, hypervelocity star production, and the effect on the structure of the host galaxy

  9. Hidden slow pulsars in binaries

    Science.gov (United States)

    Tavani, Marco; Brookshaw, Leigh

    1993-01-01

    The recent discovery of the binary containing the slow pulsar PSR 1718-19 orbiting around a low-mass companion star adds new light on the characteristics of binary pulsars. The properties of the radio eclipses of PSR 1718-19 are the most striking observational characteristics of this system. The surface of the companion star produces a mass outflow which leaves only a small 'window' in orbital phase for the detection of PSR 1718-19 around 400 MHz. At this observing frequency, PSR 1718-19 is clearly observable only for about 1 hr out of the total 6.2 hr orbital period. The aim of this Letter is twofold: (1) to model the hydrodynamical behavior of the eclipsing material from the companion star of PSR 1718-19 and (2) to argue that a population of binary slow pulsars might have escaped detection in pulsar surveys carried out at 400 MHz. The possible existence of a population of partially or totally hidden slow pulsars in binaries will have a strong impact on current theories of binary evolution of neutron stars.

  10. Laser--plasma interaction in a theta-pinch geometry

    International Nuclear Information System (INIS)

    Armstrong, W.T.

    1978-06-01

    Prompt stimulated Brillouin scatter (SBS) is studied in an experiment wherein a high power, pulsed CO 2 laser irradiates an independently produced, theta-pinch plasma. SBS does not significantly affect laser heating of the plasma. Measurements of density profiles and temperature histories permitted examination of laser refraction, local heating and net absorption. Refractive containment of the CO 2 laser beam by an on-axis density minimum was observed at early times during the laser pulse. However, refractive containment was lost at late times due to the diffusive loss of the density minimum. Classical modeling of the expected heating required ''bleached'' absorption to account for the observed heating. A plasma absorptivity of approximately 46% was inferred from calorimetry measurements at 250 mtorr fill pressure. These results confirm that classical heating and refraction dominated the laser-plasma interaction

  11. Perceptual biases for rhythm: The Mismatch Negativity latency indexes the privileged status of binary vs non-binary interval ratios.

    Science.gov (United States)

    Pablos Martin, X; Deltenre, P; Hoonhorst, I; Markessis, E; Rossion, B; Colin, C

    2007-12-01

    Rhythm perception appears to be non-linear as human subjects are better at discriminating, categorizing and reproducing rhythms containing binary vs non-binary (e.a. 1:2 vs 1:3) as well as metrical vs non-metrical (e.a. 1:2 vs 1:2.5) interval ratios. This study examined the representation of binary and non-binary interval ratios within the sensory memory, thus yielding a truly sensory, pre-motor, attention-independent neural representation of rhythmical intervals. Five interval ratios, one binary, flanked by four non-binary ones, were compared on the basis of the MMN they evoked when contrasted against a common standard interval. For all five intervals, the larger the contrast was, the larger the MMN amplitude was. The binary interval evoked a significantly much shorter (by at least 23 ms) MMN latency than the other intervals, whereas no latency difference was observed between the four non-binary intervals. These results show that the privileged perceptual status of binary rhythmical intervals is already present in the sensory representations found in echoic memory at an early, automatic, pre-perceptual and pre-motor level. MMN latency can be used to study rhythm perception at a truly sensory level, without any contribution from the motor system.

  12. SECULAR EVOLUTION OF BINARIES NEAR MASSIVE BLACK HOLES: FORMATION OF COMPACT BINARIES, MERGER/COLLISION PRODUCTS AND G2-LIKE OBJECTS

    International Nuclear Information System (INIS)

    Prodan, Snezana; Antonini, Fabio; Perets, Hagai B.

    2015-01-01

    Here we discuss the evolution of binaries around massive black holes (MBHs) in nuclear stellar clusters. We focus on their secular evolution due to the perturbation by the MBHs, while simplistically accounting for their collisional evolution. Binaries with highly inclined orbits with respect to their orbits around MBHs are strongly affected by secular processes, which periodically change their eccentricities and inclinations (e.g., Kozai-Lidov cycles). During periapsis approach, dissipative processes such as tidal friction may become highly efficient, and may lead to shrinkage of a binary orbit and even to its merger. Binaries in this environment can therefore significantly change their orbital evolution due to the MBH third-body perturbative effects. Such orbital evolution may impinge on their later stellar evolution. Here we follow the secular dynamics of such binaries and its coupling to tidal evolution, as well as the stellar evolution of such binaries on longer timescales. We find that stellar binaries in the central parts of nuclear stellar clusters (NSCs) are highly likely to evolve into eccentric and/or short-period binaries, and become strongly interacting binaries either on the main sequence (at which point they may even merge), or through their later binary stellar evolution. The central parts of NSCs therefore catalyze the formation and evolution of strongly interacting binaries, and lead to the enhanced formation of blue stragglers, X-ray binaries, gravitational wave sources, and possible supernova progenitors. Induced mergers/collisions may also lead to the formation of G2-like cloud-like objects such as the one recently observed in the Galactic center

  13. Theta Burst Transcranial Magnetic Stimulation for Auditory Verbal Hallucinations : Negative Findings From a Double-Blind-Randomized Trial

    NARCIS (Netherlands)

    Koops, Sanne; van Dellen, Edwin; Schutte, Maya J L; Nieuwdorp, Wendy; Neggers, Sebastiaan F W; Sommer, Iris E C

    BACKGROUND: Auditory verbal hallucinations (AVH) in schizophrenia are resistant to antipsychotic medication in approximately 25% of patients. Treatment with repetitive transcranial magnetic stimulation (rTMS) for refractory AVH has shown varying results. A stimulation protocol using continuous theta

  14. Galactic binaries with eLISA

    OpenAIRE

    Nelemans, G.

    2013-01-01

    I review what eLISA will see from Galactic binaries -- double stars with orbital periods less than a few hours and white dwarf (or neutron star/black hole) components. I discuss the currently known binaries that are guaranteed (or verification) sources and explain why the expected total number of eLISA Galactic binaries is several thousand, even though there are large uncertainties in our knowledge of this population, in particular that of the interacting AM CVn systems. I very briefly sketch...

  15. The origin of the RS CVn binaries

    International Nuclear Information System (INIS)

    Biermann, P.

    1976-01-01

    Six possible origins for the RS CVn binaries are considered based on the following possibilities. RS CVn binaries might now be either pre-main-sequence or post-main-sequence. A pre-main-sequence binary might not always have been a binary but might have resulted from fission of a rapidly rotating single pre-main-sequence star. The main-sequence counterparts might be either single stars or binaries. To decide which of the six origins is possible, the following observed data for the RS CVn binaries are considered: total mass, total angular momentum, lack of observed connection with regions of star formation, large space density, kinematical age, and the visual companion of WW Dra. In addition lifetimes and space densities of single stars and other types of binaries are considered. The only origin possible is that the RS CVn binaries are in a thermal phase following fission of a main-sequence single star. In this explanation the single star had a rapidly rotating core which became unstable due to the core contraction which made it begin to evolve off the main sequence. The present Be stars might be examples of such parent single stars. (Auth.)

  16. Chromatically unique 6-bridge graph theta(a,a,a,b,b,c

    Directory of Open Access Journals (Sweden)

    N.S.A. Karim

    2016-04-01

    Full Text Available For a graph $G$, let $P(G,\\lambda$ denote the chromatic polynomial of $G$. Two graphs $G$ and $H$ are chromatically equivalent if they share the same chromatic polynomial. A graph $G$ is chromatically unique if for any graph chromatically equivalent to $G$ is isomorphic to $G$. In this paper, the chromatically unique of a new family of 6-bridge graph $\\theta(a,a,a,b,b,c$ where $2\\le a\\le b\\le c$ is investigated.

  17. Evolution of dwarf binaries

    International Nuclear Information System (INIS)

    Tutukov, A.V.; Fedorova, A.V.; Yungel'son, L.R.

    1982-01-01

    The conditions of mass exchange in close binary systems with masses of components less or equal to one solar mass have been analysed for the case, when the system radiates gravitational waves. It has been shown that the mass exchange rate depends in a certain way on the mass ratio of components and on the mass of component that fills its inner critical lobe. The comparison of observed periods, masses of contact components, and mass exchange rates of observed cataclysmic binaries have led to the conclusion that the evolution of close binaries WZ Sge, OY Car, Z Cha, TT Ari, 2A 0311-227, and G 61-29 may be driven by the emission of gravitational waves [ru

  18. The neuronal mechanisms underlying improvement of impulsivity in ADHD by theta/beta neurofeedback.

    Science.gov (United States)

    Bluschke, Annet; Broschwitz, Felicia; Kohl, Simon; Roessner, Veit; Beste, Christian

    2016-08-12

    Neurofeedback is increasingly recognized as an intervention to treat core symptoms of attention deficit hyperactivity disorder (ADHD). Despite the large number of studies having been carried out to evaluate its effectiveness, it is widely elusive what neuronal mechanisms related to the core symptoms of ADHD are modulated by neurofeedback. 19 children with ADHD undergoing 8 weeks of theta/beta neurofeedback and 17 waiting list controls performed a Go/Nogo task in a pre-post design. We used neurophysiological measures combining high-density EEG recording with source localization analyses using sLORETA. Compared to the waiting list ADHD control group, impulsive behaviour measured was reduced after neurofeedback treatment. The effects of neurofeedback were very specific for situations requiring inhibitory control over responses. The neurophysiological data shows that processes of perceptual gating, attentional selection and resource allocation processes were not affected by neurofeedback. Rather, neurofeedback effects seem to be based on the modulation of response inhibition processes in medial frontal cortices. The study shows that specific neuronal mechanisms underlying impulsivity are modulated by theta/beta neurofeedback in ADHD. The applied neurofeedback protocol could be particularly suitable to address inhibitory control. The study validates assumed functional neuroanatomical target regions of an established neurofeedback protocol on a neurophysiological level.

  19. Massive binaries in the vicinity of Sgr A*

    Energy Technology Data Exchange (ETDEWEB)

    Pfuhl, O.; Gillessen, S.; Genzel, R.; Eisenhauer, F.; Fritz, T. K.; Ott, T. [Max-Planck-Institut für Extraterrestrische Physik, D-85748 Garching (Germany); Alexander, T. [Faculty of Physics, Weizmann Institute of Science, P.O. Box 26, Rehovot 76100 (Israel); Martins, F., E-mail: pfuhl@mpe.mpg.de [LUPM, Université Montpelier 2, CNRS, Place Eugéne Bataillon, F-34095, Montpellier (France)

    2014-02-20

    A long-term spectroscopic and photometric survey of the most luminous and massive stars in the vicinity of the supermassive black hole Sgr A* revealed two new binaries: a long-period Ofpe/WN9 binary, IRS 16NE, with a modest eccentricity of 0.3 and a period of 224 days, and an eclipsing Wolf-Rayet binary with a period of 2.3 days. Together with the already identified binary IRS 16SW, there are now three confirmed OB/WR binaries in the inner 0.2 pc of the Galactic center. Using radial velocity change upper limits, we were able to constrain the spectroscopic binary fraction in the Galactic center to F{sub SB}=0.30{sub −0.21}{sup +0.34} at a confidence level of 95%, a massive binary fraction close to that observed in dense clusters. The fraction of eclipsing binaries with photometric amplitudes Δm > 0.4 is F{sub EB}{sup GC}=3%±2%, which is consistent with local OB star clusters (F {sub EB} = 1%). Overall, the Galactic center binary fraction seems to be similar to the binary fraction in comparable young clusters.

  20. EVOLUTION OF THE BINARY FRACTION IN DENSE STELLAR SYSTEMS

    International Nuclear Information System (INIS)

    Fregeau, John M.; Ivanova, Natalia; Rasio, Frederic A.

    2009-01-01

    Using our recently improved Monte Carlo evolution code, we study the evolution of the binary fraction in globular clusters. In agreement with previous N-body simulations, we find generally that the hard binary fraction in the core tends to increase with time over a range of initial cluster central densities for initial binary fractions ∼<90%. The dominant processes driving the evolution of the core binary fraction are mass segregation of binaries into the cluster core and preferential destruction of binaries there. On a global scale, these effects and the preferential tidal stripping of single stars tend to roughly balance, leading to overall cluster binary fractions that are roughly constant with time. Our findings suggest that the current hard binary fraction near the half-mass radius is a good indicator of the hard primordial binary fraction. However, the relationship between the true binary fraction and the fraction of main-sequence stars in binaries (which is typically what observers measure) is nonlinear and rather complicated. We also consider the importance of soft binaries, which not only modify the evolution of the binary fraction, but can also drastically change the evolution of the cluster as a whole. Finally, we briefly describe the recent addition of single and binary stellar evolution to our cluster evolution code.

  1. Activity coefficients of solutes in binary solvents

    International Nuclear Information System (INIS)

    Gokcen, N.A.

    1982-01-01

    The activity coefficients in dilute ternary systems are discussed in detail by using the Margules equations. Analyses of some relevant data at high temperatures show that the sparingly dissolved solutes in binary solvents follow complex behavior even when the binary solvents are very nearly ideal. It is shown that the activity data on the solute or the binary system cannot permit computation of the remaining activities except for the regular solutions. It is also shown that a fourth-order equation is usually adequate in expressing the activity coefficient of a solute in binary solvents at high temperatures. When the activity data for a binary solvent are difficult to obtain in a certain range of composition, the activity data for a sparingly dissolved solute can be used to supplement determination of the binary activities

  2. A Theta lift representation for the Kawazumi-Zhang and Faltings invariants of genus-two Riemann surfaces

    CERN Document Server

    Pioline, Boris

    2016-01-01

    The Kawazumi-Zhang invariant $\\varphi$ for compact genus-two Riemann surfaces was recently shown to be a eigenmode of the Laplacian on the Siegel upper half-plane, away from the separating degeneration divisor. Using this fact and the known behavior of $\\varphi$ in the non-separating degeneration limit, it is shown that $\\varphi$ is equal to the Theta lift of the unique (up to normalization) weak Jacobi form of weight $-2$. This identification provides the complete Fourier-Jacobi expansion of $\\varphi$ near the non-separating node, gives full control on the asymptotics of $\\varphi$ in the various degeneration limits, and provides a efficient numerical procedure to evaluate $\\varphi$ to arbitrary accuracy. It also reveals a mock-type holomorphic Siegel modular form of weight $-2$ underlying $\\varphi$. From the general relation between the Faltings invariant, the Kawazumi-Zhang invariant and the discriminant for hyperelliptic Riemann surfaces, a Theta lift representation for the Faltings invariant in genus two ...

  3. All-optical conversion scheme: Binary to quaternary and quaternary to binary number

    Science.gov (United States)

    Chattopadhyay, Tanay; Roy, Jitendra Nath

    2009-04-01

    To achieve the inherent parallelism in optics a suitable number system and efficient encoding/decoding scheme for handling the data are very much essential. Binary number is accepted as the best representing number system in almost all types of existing electronic computers. But, binary number (0 and 1) is insufficient in respect to the demand of the coming generation. Multi-valued logic (with radix >2) can be viewed as an alternative approach to solve many problems in transmission, storage and processing of large amount of information in digital signal processing. Here, in this paper all-optical scheme for the conversion of binary to quaternary number and vice versa have been proposed and described. Simulation has also been done. In this all-optical scheme the numbers are represented by different discrete polarized state of light.

  4. COSMIC probes into compact binary formation and evolution

    Science.gov (United States)

    Breivik, Katelyn

    2018-01-01

    The population of compact binaries in the galaxy represents the final state of all binaries that have lived up to the present epoch. Compact binaries present a unique opportunity to probe binary evolution since many of the interactions binaries experience can be imprinted on the compact binary population. By combining binary evolution simulations with catalogs of observable compact binary systems, we can distill the dominant physical processes that govern binary star evolution, as well as predict the abundance and variety of their end products.The next decades herald a previously unseen opportunity to study compact binaries. Multi-messenger observations from telescopes across all wavelengths and gravitational-wave observatories spanning several decades of frequency will give an unprecedented view into the structure of these systems and the composition of their components. Observations will not always be coincident and in some cases may be separated by several years, providing an avenue for simulations to better constrain binary evolution models in preparation for future observations.I will present the results of three population synthesis studies of compact binary populations carried out with the Compact Object Synthesis and Monte Carlo Investigation Code (COSMIC). I will first show how binary-black-hole formation channels can be understood with LISA observations. I will then show how the population of double white dwarfs observed with LISA and Gaia could provide a detailed view of mass transfer and accretion. Finally, I will show that Gaia could discover thousands black holes in the Milky Way through astrometric observations, yielding view into black-hole astrophysics that is complementary to and independent from both X-ray and gravitational-wave astronomy.

  5. Binary versus non-binary information in real time series: empirical results and maximum-entropy matrix models

    Science.gov (United States)

    Almog, Assaf; Garlaschelli, Diego

    2014-09-01

    The dynamics of complex systems, from financial markets to the brain, can be monitored in terms of multiple time series of activity of the constituent units, such as stocks or neurons, respectively. While the main focus of time series analysis is on the magnitude of temporal increments, a significant piece of information is encoded into the binary projection (i.e. the sign) of such increments. In this paper we provide further evidence of this by showing strong nonlinear relations between binary and non-binary properties of financial time series. These relations are a novel quantification of the fact that extreme price increments occur more often when most stocks move in the same direction. We then introduce an information-theoretic approach to the analysis of the binary signature of single and multiple time series. Through the definition of maximum-entropy ensembles of binary matrices and their mapping to spin models in statistical physics, we quantify the information encoded into the simplest binary properties of real time series and identify the most informative property given a set of measurements. Our formalism is able to accurately replicate, and mathematically characterize, the observed binary/non-binary relations. We also obtain a phase diagram allowing us to identify, based only on the instantaneous aggregate return of a set of multiple time series, a regime where the so-called ‘market mode’ has an optimal interpretation in terms of collective (endogenous) effects, a regime where it is parsimoniously explained by pure noise, and a regime where it can be regarded as a combination of endogenous and exogenous factors. Our approach allows us to connect spin models, simple stochastic processes, and ensembles of time series inferred from partial information.

  6. Binary versus non-binary information in real time series: empirical results and maximum-entropy matrix models

    International Nuclear Information System (INIS)

    Almog, Assaf; Garlaschelli, Diego

    2014-01-01

    The dynamics of complex systems, from financial markets to the brain, can be monitored in terms of multiple time series of activity of the constituent units, such as stocks or neurons, respectively. While the main focus of time series analysis is on the magnitude of temporal increments, a significant piece of information is encoded into the binary projection (i.e. the sign) of such increments. In this paper we provide further evidence of this by showing strong nonlinear relations between binary and non-binary properties of financial time series. These relations are a novel quantification of the fact that extreme price increments occur more often when most stocks move in the same direction. We then introduce an information-theoretic approach to the analysis of the binary signature of single and multiple time series. Through the definition of maximum-entropy ensembles of binary matrices and their mapping to spin models in statistical physics, we quantify the information encoded into the simplest binary properties of real time series and identify the most informative property given a set of measurements. Our formalism is able to accurately replicate, and mathematically characterize, the observed binary/non-binary relations. We also obtain a phase diagram allowing us to identify, based only on the instantaneous aggregate return of a set of multiple time series, a regime where the so-called ‘market mode’ has an optimal interpretation in terms of collective (endogenous) effects, a regime where it is parsimoniously explained by pure noise, and a regime where it can be regarded as a combination of endogenous and exogenous factors. Our approach allows us to connect spin models, simple stochastic processes, and ensembles of time series inferred from partial information. (paper)

  7. PERIODIC SIGNALS IN BINARY MICROLENSING EVENTS

    International Nuclear Information System (INIS)

    Guo, Xinyi; Stefano, Rosanne Di; Esin, Ann; Taylor, Jeffrey

    2015-01-01

    Gravitational microlensing events are powerful tools for the study of stellar populations. In particular, they can be used to discover and study a variety of binary systems. A large number of binary lenses have already been found through microlensing surveys and a few of these systems show strong evidence of orbital motion on the timescale of the lensing event. We expect that more binary lenses of this kind will be detected in the future. For binaries whose orbital period is comparable to the event duration, the orbital motion can cause the lensing signal to deviate drastically from that of a static binary lens. The most striking property of such light curves is the presence of quasi-periodic features, which are produced as the source traverses the same regions in the rotating lens plane. These repeating features contain information about the orbital period of the lens. If this period can be extracted, then much can be learned about the lensing system even without performing time-consuming, detailed light-curve modeling. However, the relative transverse motion between the source and the lens significantly complicates the problem of period extraction. To resolve this difficulty, we present a modification of the standard Lomb–Scargle periodogram analysis. We test our method for four representative binary lens systems and demonstrate its efficiency in correctly extracting binary orbital periods

  8. Evaluation of Beauveria bassiana infection in the hemolymph serum proteins of the housefly, Musca domestica L. (Diptera: Muscidae).

    Science.gov (United States)

    Mishra, Sapna; Kumar, Peeyush; Malik, Anushree

    2017-11-01

    Beauveria bassiana plays a prominent role in biocontrol of houseflies, Musca domestica (L.). Thus, a deeper insight into immune response of M. domestica during B. bassiana infection was warranted to assist the production of more efficient mycoinsecticides. The present study investigates changes in protein profile of M. domestica hemolymph serum post B. bassiana infection using two-dimensional difference gel electrophoresis (2D-DIGE) followed by identification of selected proteins by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). The non-infected or control group of flies showed an expression of 54 proteins, while M. domestica infected with B. bassiana expressed a total of 68 hemolymph serum proteins. Thirty three proteins were expressed in both groups of houseflies, whereas 35 proteins were exclusively expressed in infected flies and 21 proteins were exclusively expressed in control flies. Among the 33 proteins which were expressed in both groups of houseflies, 17 proteins showed downregulation, while16 proteins were upregulated in the infected flies compared to the non-infected ones. The results from this study are expected to facilitate better understanding of insect's immune response mechanism.

  9. Improving geothermal power plants with a binary cycle

    Science.gov (United States)

    Tomarov, G. V.; Shipkov, A. A.; Sorokina, E. V.

    2015-12-01

    The recent development of binary geothermal technology is analyzed. General trends in the introduction of low-temperature geothermal sources are summarized. The use of single-phase low-temperature geothermal fluids in binary power plants proves possible and expedient. The benefits of power plants with a binary cycle in comparison with traditional systems are shown. The selection of the working fluid is considered, and the influence of the fluid's physicochemical properties on the design of the binary power plant is discussed. The design of binary power plants is based on the chemical composition and energy potential of the geothermal fluids and on the landscape and climatic conditions at the intended location. Experience in developing a prototype 2.5 MW Russian binary power unit at Pauzhetka geothermal power plant (Kamchatka) is outlined. Most binary systems are designed individually for a specific location. Means of improving the technology and equipment at binary geothermal power plants are identified. One option is the development of modular systems based on several binary systems that employ the heat from the working fluid at different temperatures.

  10. A unified analysis of the reactor neutrino program towards the measurement of the {theta}{sub 13} mixing angle

    Energy Technology Data Exchange (ETDEWEB)

    Mention, G [DAPNIA/SPP, CEA Saclay, 91191 Gif sur Yvette (France)

    2008-05-15

    We presented a detailed quantitative discussion of the measurement of the leptonic mixing angle {theta}{sub 13} through currently scheduled reactor neutrino oscillation experiments. We focussed on Double Chooz (Phase I and II), Daya Bay (Phase I and II) and RENO experiments. We performed a unified analysis, including systematics, backgrounds and accurate experimental setup in each case. Each identified systematical uncertainty and background impact has been assessed on experimental setups following published data when available and extrapolating from Double Chooz acquired knowledge otherwise. We sum up, here, a new common analysis of their sensitivities to sin{sup 2}(2{theta}{sub 13}) and study the impact of the different systematics based on the pulls approach. Through this generic statistical analysis we discuss the advantages and drawbacks of each experimental setup.

  11. GRAVITATIONAL SLINGSHOT OF YOUNG MASSIVE STARS IN ORION

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Sourav; Tan, Jonathan C., E-mail: s.chatterjee@astro.ufl.edu, E-mail: jt@astro.ufl.edu [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States)

    2012-08-01

    The Orion Nebula Cluster (ONC) is the nearest region of massive star formation and thus a crucial testing ground for theoretical models. Of particular interest among the ONC's {approx}1000 members are: {theta}{sup 1} Ori C, the most massive binary in the cluster with stars of masses 38 and 9 M{sub Sun }; the Becklin-Neugebauer (BN) object, a 30 km s{sup -1} runaway star of {approx}8 M{sub Sun }; and the Kleinmann-Low (KL) nebula protostar, a highly obscured, {approx}15 M{sub Sun} object still accreting gas while also driving a powerful, apparently 'explosive' outflow. The unusual behavior of BN and KL is much debated: How did BN acquire its high velocity? How is this related to massive star formation in the KL nebula? Here, we report the results of a systematic survey using {approx}10{sup 7} numerical experiments of gravitational interactions of the {theta}{sup 1}C and BN stars. We show that dynamical ejection of BN from this triple system at its observed velocity leaves behind a binary with total energy and eccentricity matching those observed for {theta}{sup 1}C. Five other observed properties of {theta}{sup 1}C are also consistent with it having ejected BN and altogether we estimate that there is only a {approx}< 10{sup -5} probability that {theta}{sup 1}C has these properties by chance. We conclude that BN was dynamically ejected from the {theta}{sup 1}C system about 4500 years ago. BN then plowed through the KL massive star-forming core within the last 1000 years causing its recently enhanced accretion and outflow activity.

  12. Topological and categorical properties of binary trees

    Directory of Open Access Journals (Sweden)

    H. Pajoohesh

    2008-04-01

    Full Text Available Binary trees are very useful tools in computer science for estimating the running time of so-called comparison based algorithms, algorithms in which every action is ultimately based on a prior comparison between two elements. For two given algorithms A and B where the decision tree of A is more balanced than that of B, it is known that the average and worst case times of A will be better than those of B, i.e., ₸A(n ≤₸B(n and TWA (n≤TWB (n. Thus the most balanced and the most imbalanced binary trees play a main role. Here we consider them as semilattices and characterize the most balanced and the most imbalanced binary trees by topological and categorical properties. Also we define the composition of binary trees as a commutative binary operation, *, such that for binary trees A and B, A * B is the binary tree obtained by attaching a copy of B to any leaf of A. We show that (T,* is a commutative po-monoid and investigate its properties.

  13. Optimally cloned binary coherent states

    Science.gov (United States)

    Müller, C. R.; Leuchs, G.; Marquardt, Ch.; Andersen, U. L.

    2017-10-01

    Binary coherent state alphabets can be represented in a two-dimensional Hilbert space. We capitalize this formal connection between the otherwise distinct domains of qubits and continuous variable states to map binary phase-shift keyed coherent states onto the Bloch sphere and to derive their quantum-optimal clones. We analyze the Wigner function and the cumulants of the clones, and we conclude that optimal cloning of binary coherent states requires a nonlinearity above second order. We propose several practical and near-optimal cloning schemes and compare their cloning fidelity to the optimal cloner.

  14. Binaries and triples among asteroid pairs

    Science.gov (United States)

    Pravec, Petr; Scheirich, Peter; Kušnirák, Peter; Hornoch, Kamil; Galád, Adrián

    2015-08-01

    Despite major achievements obtained during the past two decades, our knowledge of the population and properties of small binary and multiple asteroid systems is still far from advanced. There is a numerous indirect evidence for that most small asteroid systems were formed by rotational fission of cohesionless parent asteroids that were spun up to the critical frequency presumably by YORP, but details of the process are lacking. Furthermore, as we proceed with observations of more and more binary and paired asteroids, we reveal new facts that substantially refine and sometimes change our understanding of the asteroid systems. One significant new finding we have recently obtained is that primaries of many asteroid pairs are actually binary or triple systems. The first such case found is (3749) Balam (Vokrouhlický, ApJL 706, L37, 2009). We have found 9 more binary systems among asteroid pairs within our ongoing NEOSource photometric project since October 2012. They are (6369) 1983 UC, (8306) Shoko, (9783) Tensho-kan, (10123) Fideoja, (21436) Chaoyichi, (43008) 1999 UD31, (44620) 1999 RS43, (46829) 1998 OS14 and (80218) 1999 VO123. We will review their characteristics. These paired binaries as we call them are mostly similar to binaries in the general ("background") population (of unpaired asteroids), but there are a few trends. The paired binaries tend to have larger secondaries with D_2/D_1 = 0.3 to 0.5 and they also tend to be wider systems with 8 of the 10 having orbital periods between 30 and 81 hours, than average among binaries in the general population. There may be also a larger fraction of triples; (3749) Balam is a confirmed triple, having a larger close and a smaller distant satellite, and (8306) Shoko and (10123) Fideoja are suspect triples as they show additional rotational lightcurve components with periods of 61 and 38.8 h that differ from the orbital period of 36.2 and 56.5 h, respectively. The unbound secondaries tend to be of the same size or

  15. Detecting Malicious Code by Binary File Checking

    Directory of Open Access Journals (Sweden)

    Marius POPA

    2014-01-01

    Full Text Available The object, library and executable code is stored in binary files. Functionality of a binary file is altered when its content or program source code is changed, causing undesired effects. A direct content change is possible when the intruder knows the structural information of the binary file. The paper describes the structural properties of the binary object files, how the content can be controlled by a possible intruder and what the ways to identify malicious code in such kind of files. Because the object files are inputs in linking processes, early detection of the malicious content is crucial to avoid infection of the binary executable files.

  16. Multidimensional coincidence point results for generalized $(\\psi ,\\theta ,\\varphi$-contraction on ordered metric spaces

    Directory of Open Access Journals (Sweden)

    Bhavana Deshpande

    2017-11-01

    Full Text Available The main objective of this research article is to establish some coincidence point theorem for $g$-non-decreasing mappings under generalized $(\\psi ,\\theta ,\\varphi $-contraction on a partially ordered metric space. Furthermore, we show how multidimensional results can be seen as a simple consequences of our unidimensional coincidence point theorem. Our results modify, improve, sharpen, enrich and generalize various known results.

  17. Mass Transfer in Mira-Type Binaries

    Directory of Open Access Journals (Sweden)

    Mohamed S.

    2012-06-01

    Full Text Available Detached, symbiotic binaries are generally assumed to interact via Bondi-Hoyle-Littleton (BHL wind accretion. However, the accretion rates and outflow geometries that result from this mass-transfer mechanism cannot adequately explain the observations of the nearest and best studied symbiotic binary, Mira, or the formation of some post-AGB binaries, e.g. barium stars. We propose a new mass-transfer mode for Mira-type binaries, which we call ‘wind Roche-lobe overflow’ (WRLOF, and which we demonstrate with 3D hydrodynamic simulations. Importantly, we show that the circumstellar outflows which result from WRLOF tend to be highly aspherical and strongly focused towards the binary orbital plane. Furthermore, the subsequent mass-transfer rates are at least an order of magnitude greater than the analogous BHL values. We discuss the implications of these results for the shaping of bipolar (proto-planetary nebulae and other related systems.

  18. Double phi-Step theta-Scanning Technique for Spherical Near-Field Antenna Measurements

    DEFF Research Database (Denmark)

    Laitinen, Tommi

    2008-01-01

    Probe-corrected spherical near-field antenna measurements with an arbitrary probe set certain requirements on an applicable scanning technique. The computational complexity of the general high-order probe correction technique for an arbitrary probe, that is based on the Phi scanning, is O(N4...... a specific double Phi-step thetas scanning technique for spherical near-field antenna measurements. This technique not only constitutes an alternative spherical scanning technique, but it also enables formulating an associated probe correction technique for arbitrary probes with the computational complexity...

  19. Measurement of the spin-spin correlation parameter C/sub LL/(THETA) in proton-proton scattering

    International Nuclear Information System (INIS)

    Stuart, S.J.

    1982-08-01

    The experimental procedures and methods of data analysis used to measure the spin-spin correlation parameter C/sub LL/(THETA) in proton-proton scattering at thirteen different energies in the range 300 to 800 MeV are presented. The results compare favorably with previous data. Good agreement is found with phase shift predictions at energies below 500 MeV

  20. A new formulation of theta pinch implosions - a collisionless wave model

    International Nuclear Information System (INIS)

    Tsui, K.H.

    Previous work in theta pinch implosions is characterized by anomalous resistivity owing its origin to plasma instabilities. A diametrically opposite collisionless model is proposed here that consists of an inhomogeneous wave equation. The electron velocities are solved by guiding center approximation. This model offers qualitative explanations to various effects like experimental Alfven scaling law, Alfven penetration time, sheath thickness, shock formation, shock width, piston thickness, Alfven Mach number. Although collision is not essential, the plasma has an apparent resistivity with an effective collision frequency of roughly the same as those anomalous ones used in turbulent model. (Author) [pt

  1. RADIAL VELOCITY STUDIES OF CLOSE BINARY STARS. XIV

    International Nuclear Information System (INIS)

    Pribulla, Theodor; Rucinski, Slavek M.; DeBond, Heide; De Ridder, Archie; Karmo, Toomas; Thomson, J. R.; Croll, Bryce; Ogloza, Waldemar; Pilecki, Bogumil; Siwak, Michal

    2009-01-01

    Radial velocity (RV) measurements and sine curve fits to the orbital RV variations are presented for 10 close binary systems: TZ Boo, VW Boo, EL Boo, VZ CVn, GK Cep, RW Com, V2610 Oph, V1387 Ori, AU Ser, and FT UMa. Our spectroscopy revealed two quadruple systems, TZ Boo and V2610 Oph, while three stars showing small photometric amplitudes, EL Boo, V1387 Ori, and FT UMa, were found to be triple systems. GK Cep is a close binary with a faint third component. While most of the studied eclipsing systems are contact binaries, VZ CVn and GK Cep are detached or semidetached double-lined binaries, and EL Boo, V1387 Ori, and FT UMa are close binaries of uncertain binary type. The large fraction of triple and quadruple systems found in this sample supports the hypothesis of formation of close binaries in multiple stellar systems; it also demonstrates that low photometric amplitude binaries are a fertile ground for further discoveries of multiple systems.

  2. The relationship between hippocampal EEG theta activity and locomotr behaviour in freely moving rats: effects of vigabatrin

    NARCIS (Netherlands)

    Bouwman, B.M.; Lier, H. van; Nitert, H.E.J.; Drinkenburg, W.H.I.M.; Coenen, A.M.L.; Rijn, C.M. van

    2005-01-01

    The relationship between hippocampal electroencephalogram (EEG) theta activity and locomotor speed in both spontaneous and forced walking conditions was studied in rats after vigabatrin injection (500 mg/kg i.p.). Vigabatrin increased the percentage of time that rats spent being immobile. During

  3. Microlensing Signature of Binary Black Holes

    Science.gov (United States)

    Schnittman, Jeremy; Sahu, Kailash; Littenberg, Tyson

    2012-01-01

    We calculate the light curves of galactic bulge stars magnified via microlensing by stellar-mass binary black holes along the line-of-sight. We show the sensitivity to measuring various lens parameters for a range of survey cadences and photometric precision. Using public data from the OGLE collaboration, we identify two candidates for massive binary systems, and discuss implications for theories of star formation and binary evolution.

  4. Formation and Evolution of X-ray Binaries

    Science.gov (United States)

    Fragkos, Anastasios

    X-ray binaries - mass-transferring binary stellar systems with compact object accretors - are unique astrophysical laboratories. They carry information about many complex physical processes such as star formation, compact object formation, and evolution of interacting binaries. My thesis work involves the study of the formation and evolution of Galactic and extra-galacticX-ray binaries using both detailed and realistic simulation tools, and population synthesis techniques. I applied an innovative analysis method that allows the reconstruction of the full evolutionary history of known black hole X-ray binaries back to the time of compact object formation. This analysis takes into account all the available observationally determined properties of a system, and models in detail four of its evolutionary evolutionary phases: mass transfer through the ongoing X-ray phase, tidal evolution before the onset of Roche-lobe overflow, motion through the Galactic potential after the formation of the black hole, and binary orbital dynamics at the time of core collapse. Motivated by deep extra-galactic Chandra survey observations, I worked on population synthesis models of low-mass X-ray binaries in the two elliptical galaxies NGC3379 and NGC4278. These simulations were targeted at understanding the origin of the shape and normalization of the observed X-ray luminosity functions. In a follow up study, I proposed a physically motivated prescription for the modeling of transient neutron star low-mass X-ray binary properties, such as duty cycle, outburst duration and recurrence time. This prescription enabled the direct comparison of transient low-mass X-ray binary population synthesis models to the Chandra X-ray survey of the two ellipticals NGC3379 and NGC4278. Finally, I worked on population synthesismodels of black holeX-ray binaries in the MilkyWay. This work was motivated by recent developments in observational techniques for the measurement of black hole spin magnitudes in

  5. Detectability of Gravitational Waves from High-Redshift Binaries.

    Science.gov (United States)

    Rosado, Pablo A; Lasky, Paul D; Thrane, Eric; Zhu, Xingjiang; Mandel, Ilya; Sesana, Alberto

    2016-03-11

    Recent nondetection of gravitational-wave backgrounds from pulsar timing arrays casts further uncertainty on the evolution of supermassive black hole binaries. We study the capabilities of current gravitational-wave observatories to detect individual binaries and demonstrate that, contrary to conventional wisdom, some are, in principle, detectable throughout the Universe. In particular, a binary with rest-frame mass ≳10^{10}M_{⊙} can be detected by current timing arrays at arbitrarily high redshifts. The same claim will apply for less massive binaries with more sensitive future arrays. As a consequence, future searches for nanohertz gravitational waves could be expanded to target evolving high-redshift binaries. We calculate the maximum distance at which binaries can be observed with pulsar timing arrays and other detectors, properly accounting for redshift and using realistic binary waveforms.

  6. Genetic influences on functional connectivity associated with feedback processing and prediction error: Phase coupling of theta-band oscillations in twins.

    Science.gov (United States)

    Demiral, Şükrü Barış; Golosheykin, Simon; Anokhin, Andrey P

    2017-05-01

    Detection and evaluation of the mismatch between the intended and actually obtained result of an action (reward prediction error) is an integral component of adaptive self-regulation of behavior. Extensive human and animal research has shown that evaluation of action outcome is supported by a distributed network of brain regions in which the anterior cingulate cortex (ACC) plays a central role, and the integration of distant brain regions into a unified feedback-processing network is enabled by long-range phase synchronization of cortical oscillations in the theta band. Neural correlates of feedback processing are associated with individual differences in normal and abnormal behavior, however, little is known about the role of genetic factors in the cerebral mechanisms of feedback processing. Here we examined genetic influences on functional cortical connectivity related to prediction error in young adult twins (age 18, n=399) using event-related EEG phase coherence analysis in a monetary gambling task. To identify prediction error-specific connectivity pattern, we compared responses to loss and gain feedback. Monetary loss produced a significant increase of theta-band synchronization between the frontal midline region and widespread areas of the scalp, particularly parietal areas, whereas gain resulted in increased synchrony primarily within the posterior regions. Genetic analyses showed significant heritability of frontoparietal theta phase synchronization (24 to 46%), suggesting that individual differences in large-scale network dynamics are under substantial genetic control. We conclude that theta-band synchronization of brain oscillations related to negative feedback reflects genetically transmitted differences in the neural mechanisms of feedback processing. To our knowledge, this is the first evidence for genetic influences on task-related functional brain connectivity assessed using direct real-time measures of neuronal synchronization. Copyright © 2016

  7. Isolation and characterization of a cDNA clone coding for a glutathione S-transferase class delta enzyme from the biting midge Culicoides variipennis sonorensis Wirth and Jones.

    Science.gov (United States)

    Abdallah, M A; Pollenz, R S; Droog, F N; Nunamaker, R A; Tabachnick, W J; Murphy, K E

    2000-12-01

    Culicoides variipennis sonorensis is the primary vector of bluetongue viruses in North America. Glutathione S-transferases (GSTs) are enzymes that catalyze nucleophilic substitutions, converting reactive lipophilic molecules into soluble conjugates. Increased GST activity is associated with development of insecticide resistance. Described here is the isolation of the first cDNA encoding a C. variipennis GST. The clone consists of 720 translated bases encoding a protein with a M(r) of approximately 24,800 composed of 219 amino acids. The deduced amino acid sequence is similar (64%-74%) to class Delta (previously named Theta) GSTs from the dipteran genera Musca, Drosophila, Lucilia and Anopheles. The cDNA was subcloned into pET-11b, expressed in Epicurian coli BL21 (DE3) and has a specific activity of approximately 28,000 units/mg for the substrate 1-chloro-2,4-dinitrobenzene.

  8. Non-binary Entanglement-assisted Stabilizer Quantum Codes

    OpenAIRE

    Riguang, Leng; Zhi, Ma

    2011-01-01

    In this paper, we show how to construct non-binary entanglement-assisted stabilizer quantum codes by using pre-shared entanglement between the sender and receiver. We also give an algorithm to determine the circuit for non-binary entanglement-assisted stabilizer quantum codes and some illustrated examples. The codes we constructed do not require the dual-containing constraint, and many non-binary classical codes, like non-binary LDPC codes, which do not satisfy the condition, can be used to c...

  9. Mesoscopic model for binary fluids

    Science.gov (United States)

    Echeverria, C.; Tucci, K.; Alvarez-Llamoza, O.; Orozco-Guillén, E. E.; Morales, M.; Cosenza, M. G.

    2017-10-01

    We propose a model for studying binary fluids based on the mesoscopic molecular simulation technique known as multiparticle collision, where the space and state variables are continuous, and time is discrete. We include a repulsion rule to simulate segregation processes that does not require calculation of the interaction forces between particles, so binary fluids can be described on a mesoscopic scale. The model is conceptually simple and computationally efficient; it maintains Galilean invariance and conserves the mass and energy in the system at the micro- and macro-scale, whereas momentum is conserved globally. For a wide range of temperatures and densities, the model yields results in good agreement with the known properties of binary fluids, such as the density profile, interface width, phase separation, and phase growth. We also apply the model to the study of binary fluids in crowded environments with consistent results.

  10. Kepler eclipsing binary stars. IV. Precise eclipse times for close binaries and identification of candidate three-body systems

    International Nuclear Information System (INIS)

    Conroy, Kyle E.; Stassun, Keivan G.; Prša, Andrej; Orosz, Jerome A.; Welsh, William F.; Fabrycky, Daniel C.

    2014-01-01

    We present a catalog of precise eclipse times and analysis of third-body signals among 1279 close binaries in the latest Kepler Eclipsing Binary Catalog. For these short-period binaries, Kepler's 30 minute exposure time causes significant smearing of light curves. In addition, common astrophysical phenomena such as chromospheric activity, as well as imperfections in the light curve detrending process, can create systematic artifacts that may produce fictitious signals in the eclipse timings. We present a method to measure precise eclipse times in the presence of distorted light curves, such as in contact and near-contact binaries which exhibit continuously changing light levels in and out of eclipse. We identify 236 systems for which we find a timing variation signal compatible with the presence of a third body. These are modeled for the light travel time effect and the basic properties of the third body are derived. This study complements J. A. Orosz et al. (in preparation), which focuses on eclipse timing variations of longer period binaries with flat out-of-eclipse regions. Together, these two papers provide comprehensive eclipse timings for all binaries in the Kepler Eclipsing Binary Catalog, as an ongoing resource freely accessible online to the community.

  11. The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. III. Optical and UV Spectra of a Blue Kilonova from Fast Polar Ejecta

    Energy Technology Data Exchange (ETDEWEB)

    Nicholl, M.; Berger, E.; Kasen, D.; Metzger, B. D.; Elias, J.; Briceño, C.; Alexander, K. D.; Blanchard, P. K.; Chornock, R.; Cowperthwaite, P. S.; Eftekhari, T.; Fong, W.; Margutti, R.; Villar, V. A.; Williams, P. K. G.; Brown, W.; Annis, J.; Bahramian, A.; Brout, D.; Brown, D. A.; Chen, H. -Y.; Clemens, J. C.; Dennihy, E.; Dunlap, B.; Holz, D. E.; Marchesini, E.; Massaro, F.; Moskowitz, N.; Pelisoli, I.; Rest, A.; Ricci, F.; Sako, M.; Soares-Santos, M.; Strader, J.

    2017-10-16

    We present optical and ultraviolet spectra of the first electromagnetic counterpart to a gravitational wave (GW) source, the binary neutron star merger GW170817. Spectra were obtained nightly between 1.5 and 9.5 days post-merger, using the SOAR and Magellan telescopes; the UV spectrum was obtained with the \\textit{Hubble Space Telescope} at 5.5 days. Our data reveal a rapidly-fading blue component ($T\\approx5500$ K at 1.5 days) that quickly reddens; spectra later than $\\gtrsim 4.5$ days peak beyond the optical regime. The spectra are mostly featureless, although we identify a possible weak emission line at $\\sim 7900$ \\AA\\ at $t\\lesssim 4.5$ days. The colours, rapid evolution and featureless spectrum are consistent with a "blue" kilonova from polar ejecta comprised mainly of light $r$-process nuclei with atomic mass number $A\\lesssim 140$. This indicates a sight-line within $\\theta_{\\rm obs}\\lesssim 45^{\\circ}$ of the orbital axis. Comparison to models suggests $\\sim0.03$ M$_\\odot$ of blue ejecta, with a velocity of $\\sim 0.3c$. The required lanthanide fraction is $\\sim 10^{-4}$, but this drops to $<10^{-5}$ in the outermost ejecta. The large velocities point to a dynamical origin, rather than a disk wind, for this blue component, suggesting that both binary constituents are neutron stars (as opposed to a binary consisting of a neutron star and a black hole). For dynamical ejecta, the high mass favors a small neutron star radius of $\\lesssim 12$ km. This mass also supports the idea that neutron star mergers are a major contributor to $r$-process nucleosynthesis.

  12. CIRCUMBINARY MAGNETOHYDRODYNAMIC ACCRETION INTO INSPIRALING BINARY BLACK HOLES

    Energy Technology Data Exchange (ETDEWEB)

    Noble, Scott C.; Mundim, Bruno C.; Nakano, Hiroyuki; Campanelli, Manuela; Zlochower, Yosef [Center for Computational Relativity and Gravitation, Rochester Institute of Technology, Rochester, NY 14623 (United States); Krolik, Julian H. [Physics and Astronomy Department, Johns Hopkins University, Baltimore, MD 21218 (United States); Yunes, Nicolas, E-mail: scn@astro.rit.edu [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

    2012-08-10

    We have simulated the magnetohydrodynamic evolution of a circumbinary disk surrounding an equal-mass binary comprising two non-spinning black holes during the period in which the disk inflow time is comparable to the binary evolution time due to gravitational radiation. Both the changing spacetime and the binary orbital evolution are described by an innovative technique utilizing high-order post-Newtonian approximations. Prior to the beginning of the inspiral, the structure of the circumbinary disk is predicted well by extrapolation from Newtonian results: a gap of roughly two binary separation radii is cleared, and matter piles up at the outer edge of this gap as inflow is retarded by torques exerted by the binary; the accretion rate is roughly half its value at large radius. During inspiral, the inner edge of the disk initially moves inward in coordination with the shrinking binary, but-as the orbital evolution accelerates-the inward motion of the disk edge falls behind the rate of binary compression. In this stage, the binary torque falls substantially, but the accretion rate decreases by only 10%-20%. When the binary separation is tens of gravitational radii, the rest-mass efficiency of disk radiation is a few percent, suggesting that supermassive binary black holes could be very luminous at this stage of their evolution. Inner disk heating is modulated at a beat frequency comparable to the binary orbital frequency. However, a disk with sufficient surface density to be luminous may be optically thick, suppressing periodic modulation of the luminosity.

  13. Binary and Millisecond Pulsars

    Directory of Open Access Journals (Sweden)

    Lorimer Duncan R.

    2008-11-01

    Full Text Available We review the main properties, demographics and applications of binary and millisecond radio pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1800. There are now 83 binary and millisecond pulsars associated with the disk of our Galaxy, and a further 140 pulsars in 26 of the Galactic globular clusters. Recent highlights include the discovery of the young relativistic binary system PSR J1906+0746, a rejuvination in globular cluster pulsar research including growing numbers of pulsars with masses in excess of 1.5M_⊙, a precise measurement of relativistic spin precession in the double pulsar system and a Galactic millisecond pulsar in an eccentric (e = 0.44 orbit around an unevolved companion.

  14. Observations of new Wolf-Rayet binaries

    International Nuclear Information System (INIS)

    Niemela, V.S.

    1982-01-01

    The author reports here preliminary results of spectrographic observations for three southern WR stars, whose binary nature had not been previously verified: HDE 320102, CD -45 0 4482, HD 62910. The observations were carried out at the Cerro Tololo Inter-American Observatory, Chile, mostly with the Cassegrain spectrograph with IT attached to the 1-m reflector. These spectrograms were secured on Kodak IIIaJ emulsion, and have a dispersion of 45 A/mm. The results suggest that HDE 320102 must be a double-lined 05-7 + WN3 spectroscopic binary, that CD -45 0 4482 appears to be a single-lined spectroscopic binary and that HD 62910 may be a binary. (Auth.)

  15. Spatial-area selective retrieval of multiple object-place associations in a hierarchical cognitive map formed by theta phase coding.

    Science.gov (United States)

    Sato, Naoyuki; Yamaguchi, Yoko

    2009-06-01

    The human cognitive map is known to be hierarchically organized consisting of a set of perceptually clustered landmarks. Patient studies have demonstrated that these cognitive maps are maintained by the hippocampus, while the neural dynamics are still poorly understood. The authors have shown that the neural dynamic "theta phase precession" observed in the rodent hippocampus may be capable of forming hierarchical cognitive maps in humans. In the model, a visual input sequence consisting of object and scene features in the central and peripheral visual fields, respectively, results in the formation of a hierarchical cognitive map for object-place associations. Surprisingly, it is possible for such a complex memory structure to be formed in a few seconds. In this paper, we evaluate the memory retrieval of object-place associations in the hierarchical network formed by theta phase precession. The results show that multiple object-place associations can be retrieved with the initial cue of a scene input. Importantly, according to the wide-to-narrow unidirectional connections among scene units, the spatial area for object-place retrieval can be controlled by the spatial area of the initial cue input. These results indicate that the hierarchical cognitive maps have computational advantages on a spatial-area selective retrieval of multiple object-place associations. Theta phase precession dynamics is suggested as a fundamental neural mechanism of the human cognitive map.

  16. A unified analysis of the reactor neutrino program towards the measurement of the {theta}{sub 13} mixing angle

    Energy Technology Data Exchange (ETDEWEB)

    Mention, G.; Motta, D. [DAPNIA/SPP, CEA Saclay, 91191 Gif sur Yvette (France); Lasserre, Th. [DAPNIA/SPP, CEA Saclay, 91191 Gif sur Yvette (France); Laboratoire Astroparticule et Cosmologie (APC), Paris (France)

    2007-04-15

    We present in this article a detailed quantitative discussion of the measurement of the leptonic mixing angle {theta}{sub 13} through currently scheduled reactor neutrino oscillation experiments. We thus focus on Double Chooz (Phase I and II), Daya Bay (Phase I and II) and RENO experiments. We perform a unified analysis, including systematics, backgrounds and accurate experimental setup in each case. Each identified systematic error and background impact has been assessed on experimental setups following published data when available and extrapolating from Double Chooz acquired knowledge otherwise. After reviewing the experiments, we present a new analysis of their sensitivities to sin{sup 2}(2{theta}{sub 13}) and study the impact of the different systematics based on the pulls approach. Through this generic statistical analysis we discuss the advantages and drawbacks of each experimental setup. (authors)

  17. Asteroseismic effects in close binary stars

    Science.gov (United States)

    Springer, Ofer M.; Shaviv, Nir J.

    2013-09-01

    Turbulent processes in the convective envelopes of the Sun and stars have been shown to be a source of internal acoustic excitations. In single stars, acoustic waves having frequencies below a certain cut-off frequency propagate nearly adiabatically and are effectively trapped below the photosphere where they are internally reflected. This reflection essentially occurs where the local wavelength becomes comparable to the pressure scale height. In close binary stars, the sound speed is a constant on equipotentials, while the pressure scale height, which depends on the local effective gravity, varies on equipotentials and may be much greater near the inner Lagrangian point (L1). As a result, waves reaching the vicinity of L1 may propagate unimpeded into low-density regions, where they tend to dissipate quickly due to non-linear and radiative effects. We study the three-dimensional propagation and enhanced damping of such waves inside a set of close binary stellar models using a WKB approximation of the acoustic field. We find that these waves can have much higher damping rates in close binaries, compared to their non-binary counterparts. We also find that the relative distribution of acoustic energy density at the visible surface of close binaries develops a ring-like feature at specific acoustic frequencies and binary separations.

  18. Probability laws related to the Jacobi theta and Riemann zeta function and Brownian excursions

    OpenAIRE

    Biane, P.; Pitman, J.; Yor, M.

    1999-01-01

    This paper reviews known results which connect Riemann's integral representations of his zeta function, involving Jacobi's theta function and its derivatives, to some particular probability laws governing sums of independent exponential variables. These laws are related to one-dimensional Brownian motion and to higher dimensional Bessel processes. We present some characterizations of these probability laws, and some approximations of Riemann's zeta function which are related to these laws.

  19. Sustainable production of housefly (Musca domestica) larvae as a protein-rich feed ingredient by utilizing cattle manure

    Science.gov (United States)

    Hussein, Mahmoud; Pillai, Viju V.; Goddard, Joshua M.; Park, Hui G.; Kothapalli, Kumar S.; Ross, Deborah A.; Ketterings, Quirine M.; Brenna, J. Thomas; Milstein, Mark B.; Marquis, Helene; Johnson, Patricia A.; Nyrop, Jan P.

    2017-01-01

    The common housefly, Musca domestica, is a considerable component of nutrient recycling in the environment. Use of housefly larvae to biodegrade manure presents an opportunity to reduce waste disposal while the rapidly assimilated insect biomass can also be used as a protein rich animal feed. In this study, we examine the biodegradation of dairy cattle manure using housefly larvae, and the nutritional value of the resulting larva meal as a feed ingredient. Our results demonstrated that dairy cattle manure presents a balanced substrate for larval growth, and the spent manure showed reductions in concentration of total nitrogen (24.9%) and phosphorus (6.2%) with an overall reduction in mass. Larva yield at an optimum density was approximately 2% of manure weight. Nutritional analysis of M. domestica larva meal showed values comparable to most high protein feed ingredients. Larva meal was 60% protein with a well-balanced amino acid profile, and 20% fat with 57% monounsaturated fatty acids, and 39% saturated fatty acids. Larva meal lacked any significant amount of omega-3 fatty acids. Evaluation of micronutrients in larva meal suggested that it is a good source of calcium and phosphorus (0.5% and 1.1% respectively). The nutritional value of larva meal closely matches that of fishmeal, making it a potentially attractive alternative for use as a protein-rich feed ingredient for livestock and aquaculture operations. PMID:28170420

  20. Logistic chaotic maps for binary numbers generations

    International Nuclear Information System (INIS)

    Kanso, Ali; Smaoui, Nejib

    2009-01-01

    Two pseudorandom binary sequence generators, based on logistic chaotic maps intended for stream cipher applications, are proposed. The first is based on a single one-dimensional logistic map which exhibits random, noise-like properties at given certain parameter values, and the second is based on a combination of two logistic maps. The encryption step proposed in both algorithms consists of a simple bitwise XOR operation of the plaintext binary sequence with the keystream binary sequence to produce the ciphertext binary sequence. A threshold function is applied to convert the floating-point iterates into binary form. Experimental results show that the produced sequences possess high linear complexity and very good statistical properties. The systems are put forward for security evaluation by the cryptographic committees.

  1. The theta-pinch - a versatile tool for the generation and study of high temperature plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Hintz, E. [Inst. fuer Plasmaphysik, Forschungszentrum-Juelich GmbH (Germany)

    2004-07-01

    The more general technical and physical features of theta-pinches are described. Special field of their application are high-ss plasmas. Two examples are analysed and studied in more detail: a high density plasma near thermal equilibrium and a low density plasma far from equilibrium. The latter is of special interest for future investigations. Possibilities of field-reversed configurations are pointed out. (orig.)

  2. The theta-pinch - a versatile tool for the generation and study of high temperature plasmas

    International Nuclear Information System (INIS)

    Hintz, E.

    2004-01-01

    The more general technical and physical features of theta-pinches are described. Special field of their application are high-ss plasmas. Two examples are analysed and studied in more detail: a high density plasma near thermal equilibrium and a low density plasma far from equilibrium. The latter is of special interest for future investigations. Possibilities of field-reversed configurations are pointed out. (orig.)

  3. Converting optical scanning holograms of real objects to binary Fourier holograms using an iterative direct binary search algorithm.

    Science.gov (United States)

    Leportier, Thibault; Park, Min Chul; Kim, You Seok; Kim, Taegeun

    2015-02-09

    In this paper, we present a three-dimensional holographic imaging system. The proposed approach records a complex hologram of a real object using optical scanning holography, converts the complex form to binary data, and then reconstructs the recorded hologram using a spatial light modulator (SLM). The conversion from the recorded hologram to a binary hologram is achieved using a direct binary search algorithm. We present experimental results that verify the efficacy of our approach. To the best of our knowledge, this is the first time that a hologram of a real object has been reconstructed using a binary SLM.

  4. Theta, mental flexibility, and post-traumatic stress disorder: connecting in the parietal cortex.

    Directory of Open Access Journals (Sweden)

    Benjamin T Dunkley

    Full Text Available Post-traumatic stress disorder (PTSD is a mental health injury characterised by re-experiencing, avoidance, numbing and hyperarousal. Whilst the aetiology of the disorder is relatively well understood, there is debate about the prevalence of cognitive sequelae that manifest in PTSD. In particular, there are conflicting reports about deficits in executive function and mental flexibility. Even less is known about the neural changes that underlie such deficits. Here, we used magnetoencephalography to study differences in functional connectivity during a mental flexibility task in combat-related PTSD (all males, mean age = 37.4, n = 18 versus a military control (all males, mean age = 33.05, n = 19 group. We observed large-scale increases in theta connectivity in the PTSD group compared to controls. The PTSD group performance was compromised in the more attentionally-demanding task and this was characterised by 'late-stage' theta hyperconnectivity, concentrated in network connections involving right parietal cortex. Furthermore, we observed significant correlations with the connectivity strength in this region with a number of cognitive-behavioural outcomes, including measures of attention, depression and anxiety. These findings suggest atypical coordination of neural synchronisation in large scale networks contributes to deficits in mental flexibility for PTSD populations in timed, attentionally-demanding tasks, and this propensity toward network hyperconnectivity may play a more general role in the cognitive sequelae evident in this disorder.

  5. EXTRASOLAR BINARY PLANETS. II. DETECTABILITY BY TRANSIT OBSERVATIONS

    International Nuclear Information System (INIS)

    Lewis, K. M.; Ida, S.; Ochiai, H.; Nagasawa, M.

    2015-01-01

    We discuss the detectability of gravitationally bound pairs of gas-giant planets (which we call “binary planets”) in extrasolar planetary systems that are formed through orbital instability followed by planet–planet dynamical tides during their close encounters, based on the results of N-body simulations by Ochiai et al. (Paper I). Paper I showed that the formation probability of a binary is as much as ∼10% for three giant planet systems that undergo orbital instability, and after post-capture long-term tidal evolution, the typical binary separation is three to five times the sum of the physical radii of the planets. The binary planets are stable during the main-sequence lifetime of solar-type stars, if the stellarcentric semimajor axis of the binary is larger than 0.3 AU. We show that detecting modulations of transit light curves is the most promising observational method to detect binary planets. Since the likely binary separations are comparable to the stellar diameter, the shape of the transit light curve is different from transit to transit, depending on the phase of the binary’s orbit. The transit durations and depth for binary planet transits are generally longer and deeper than those for the single planet case. We point out that binary planets could exist among the known inflated gas-giant planets or objects classified as false positive detections at orbital radii ≳0.3 AU, propose a binary planet explanation for the CoRoT candidate SRc01 E2 1066, and show that binary planets are likely to be present in, and could be detected using, Kepler-quality data

  6. Enterobacteria associated with houseflies (Musca domestica) as an infection risk indicator in swine production farms.

    Science.gov (United States)

    Cervelin, V; Fongaro, G; Pastore, J B; Engel, F; Reimers, M A; Viancelli, A

    2018-04-23

    Houseflies (Musca domestica) spend part of their life development on animal or human manure. Manure is high in pathogenic microbes; thus, houseflies have been known as a mechanical vector for various important zoonotic diseases. Therefore, the present study showcases captured houseflies from intensive swine production regions (which are areas of high manure concentration) in Southern Brazil, and analyses their bodies' to the presence of Escherichia coli and Salmonella sp. and the sensitivity of these bacteria to various antibiotics. Additionally, Quantitative Microbiology Risk Assessment was performed simulating the contamination of lettuce by flies' bacteria and subsequent lettuce consumption by an adult human being. Houseflies were captured in swine buildings and farm houses from five farms. E. coli quantification values ranged from 10 4 to 10 6 CFU/20 flies, and all sampling sites had positive results from bacteria presence in the collected houseflies. On the other hand, Salmonella sp. presence was observed in only three farms, where the quantification ranged from 10 2 to 10 5 CFU/20 flies. The bacteria showed to be resistant to at least two from the four tested antibiotics (ampicillin, Cefalotin, Ciprofloxacin and Norfloxacin) antibiotics used in human or veterinary medicine. Infection probability analyses showed risk of human infection by E.coli, indicating possible transmission of zoonotic pathogens through flies. In this context, it was possible to conclude that there is a need for flies control, especially in swine farms where zoonotic pathogens can be abundant, to minimize the health impact of the vectorization of enteric bacteria. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Interaction of Massive Black Hole Binaries with Their Stellar Environment. II. Loss Cone Depletion and Binary Orbital Decay

    Science.gov (United States)

    Sesana, Alberto; Haardt, Francesco; Madau, Piero

    2007-05-01

    We study the long-term evolution of massive black hole binaries (MBHBs) at the centers of galaxies using detailed scattering experiments to solve the full three-body problem. Ambient stars drawn from an isotropic Maxwellian distribution unbound to the binary are ejected by the gravitational slingshot. We construct a minimal, hybrid model for the depletion of the loss cone and the orbital decay of the binary and show that secondary slingshots-stars returning on small-impact parameter orbits to have a second superelastic scattering with the MBHB-may considerably help the shrinking of the pair in the case of large binary mass ratios. In the absence of loss cone refilling by two-body relaxation or other processes, the mass ejected before the stalling of a MBHB is half the binary reduced mass. About 50% of the ejected stars are expelled in a ``burst'' lasting ~104 yr M1/46, where M6 is the binary mass in units of 106 Msolar. The loss cone is completely emptied in a few bulge crossing timescales, ~107 yr M1/46. Even in the absence of two-body relaxation or gas dynamical processes, unequal mass and/or eccentric binaries with M6>~0.1 can shrink to the gravitational wave emission regime in less than a Hubble time and are therefore ``safe'' targets for the planned Laser Interferometer Space Antenna.

  8. Recalling and forgetting dreams: theta and alpha oscillations during sleep predict subsequent dream recall.

    Science.gov (United States)

    Marzano, Cristina; Ferrara, Michele; Mauro, Federica; Moroni, Fabio; Gorgoni, Maurizio; Tempesta, Daniela; Cipolli, Carlo; De Gennaro, Luigi

    2011-05-04

    Under the assumption that dream recall is a peculiar form of declarative memory, we have hypothesized that (1) the encoding of dream contents during sleep should share some electrophysiological mechanisms with the encoding of episodic memories of the awake brain and (2) recalling a dream(s) after awakening from non-rapid eye movement (NREM) and rapid eye movement (REM) sleep should be associated with different brain oscillations. Here, we report that cortical brain oscillations of human sleep are predictive of successful dream recall. In particular, after morning awakening from REM sleep, a higher frontal 5-7 Hz (theta) activity was associated with successful dream recall. This finding mirrors the increase in frontal theta activity during successful encoding of episodic memories in wakefulness. Moreover, in keeping with the different EEG background, a different predictive relationship was found after awakening from stage 2 NREM sleep. Specifically, a lower 8-12 Hz (alpha) oscillatory activity of the right temporal area was associated with a successful dream recall. These findings provide the first evidence of univocal cortical electroencephalographic correlates of dream recall, suggesting that the neurophysiological mechanisms underlying the encoding and recall of episodic memories may remain the same across different states of consciousness.

  9. Is theta burst stimulation applied to visual cortex able to modulate peripheral visual acuity?

    Directory of Open Access Journals (Sweden)

    Sabrina Brückner

    Full Text Available Repetitive transcranial magnetic stimulation is usually applied to visual cortex to explore the effects on cortical excitability. Most researchers therefore concentrate on changes of phosphene threshold, rarely on consequences for visual performance. Thus, we investigated peripheral visual acuity in the four quadrants of the visual field using Landolt C optotypes before and after repetitive stimulation of the visual cortex. We applied continuous and intermittend theta burst stimulation with various stimulation intensities (60%, 80%, 100%, 120% of individual phosphene threshold as well as monophasic and biphasic 1 Hz stimulation, respectively. As an important result, no serious adverse effects were observed. In particular, no seizure was induced, even with theta burst stimulation applied with 120% of individual phosphene threshold. In only one case stimulation was ceased because the subject reported intolerable pain. Baseline visual acuity decreased over sessions, indicating a continuous training effect. Unexpectedly, none of the applied transcranial magnetic stimulation protocols had an effect on performance: no change in visual acuity was found in any of the four quadrants of the visual field. Binocular viewing as well as the use of peripheral instead of foveal presentation of the stimuli might have contributed to this result. Furthermore, intraindividual variability could have masked the TMS- induced effects on visual acuity.

  10. Microscopic investigation to determine the effect of Beauveria bassiana (Bals.) Vuill. and Cymbopogon citratus (DC.) Stapf. treatment on different life stages of Musca domestica (L.).

    Science.gov (United States)

    Mishra, Sapna; Kumar, Peeyush; Malik, Anushree

    2017-06-01

    Microscopic investigation was done to determine the effect of entomopathogenic fungi, Beauveria bassiana and essential oil of Cymbopogon citratus on different life stages of Musca domestica . Scanning electron microscopy investigation of fungal infected larvae showed sluggish movement, rigor, and failure of body to balance in water. Treated larvae also revealed varied level of cuticle shrinkage and extreme dehydration. Surface of B. bassiana infected pupae showed varied stage of mycelial growth, while the cadaver of adult fly was observed to have extensive fungal growth covering their entire body surface. The application of C. citratus oils on M. domestica larvae resulted in skin shrinkage, spinous cells proliferation and bleb formation, while the treated pupae showed high incidence of incomplete emergence and malformation in emerged adult flies. The current study establishes effect of C. citratus essential oil and B. bassiana infection on different life stages of M. domestica .

  11. Refrigeration requirements for fusion reactors based upon the theta-pinch concept

    International Nuclear Information System (INIS)

    Williamson, K.D. Jr.; King, C.R.

    1976-01-01

    Two refrigeration systems applicable to the theta-pinch fusion concept are described. The first is a 1100 W, 4.5 K refrigerator which will be used for testing superconducting NbTi Magnetic Energy Transfer and Storage (METS) coil systems. This unit is currently being installed and is to be operational by April 1977. The second unit is applicable to the Syllac Fusion Test Reactor (SFTR) and has been conceptually designed. This liquefier-refrigerator is about 22 times larger than those in existence at present and will require 12-MW input electrical power. It will provide 3045 kg/h of liquid helium at 4.5 K

  12. Glutathione-binding site of a bombyx mori theta-class glutathione transferase.

    Directory of Open Access Journals (Sweden)

    M D Tofazzal Hossain

    Full Text Available The glutathione transferase (GST superfamily plays key roles in the detoxification of various xenobiotics. Here, we report the isolation and characterization of a silkworm protein belonging to a previously reported theta-class GST family. The enzyme (bmGSTT catalyzes the reaction of glutathione with 1-chloro-2,4-dinitrobenzene, 1,2-epoxy-3-(4-nitrophenoxy-propane, and 4-nitrophenethyl bromide. Mutagenesis of highly conserved residues in the catalytic site revealed that Glu66 and Ser67 are important for enzymatic function. These results provide insights into the catalysis of glutathione conjugation in silkworm by bmGSTT and into the metabolism of exogenous chemical agents.

  13. Field-reversed configuration produced by a linear theta-pinch, Tupa-1

    International Nuclear Information System (INIS)

    Kayama, M.E.; Boeckelmann, H.K.; Sakanaka, P.H.; Machida, M.

    1987-01-01

    The formation of field reversed configuration, FRC, in one meter mirrorless linear theta-pinch device Tupa-I was observed. This configuration was studied during the first half magnetic cycle of ringing main bank discharge using magnetic probes. The separatrix radius by the exclude flux probe and the ion temperature by visible spectroscopy were measured. The plasma dynamics was observed by the image converter camera. A clear indication of the formation of FRC due to reconnection of the antiparallel bias to the main field and a fast reconnection, less than 0.2 microsec, that is explained in terms of forced reconnection driven by the Kruskal-Schwarzschild instability, are also observed. (author) [pt

  14. Merger rate of primordial black-hole binaries

    Science.gov (United States)

    Ali-Haïmoud, Yacine; Kovetz, Ely D.; Kamionkowski, Marc

    2017-12-01

    Primordial black holes (PBHs) have long been a candidate for the elusive dark matter (DM), and remain poorly constrained in the ˜20 - 100 M⊙ mass range. PBH binaries were recently suggested as the possible source of LIGO's first detections. In this paper, we thoroughly revisit existing estimates of the merger rate of PBH binaries. We compute the probability distribution of orbital parameters for PBH binaries formed in the early Universe, accounting for tidal torquing by all other PBHs, as well as standard large-scale adiabatic perturbations. We then check whether the orbital parameters of PBH binaries formed in the early Universe can be significantly affected between formation and merger. Our analytic estimates indicate that the tidal field of halos and interactions with other PBHs, as well as dynamical friction by unbound standard DM particles, do not do significant work on nor torque PBH binaries. We estimate the torque due to baryon accretion to be much weaker than previous calculations, albeit possibly large enough to significantly affect the eccentricity of typical PBH binaries. We also revisit the PBH-binary merger rate resulting from gravitational capture in present-day halos, accounting for Poisson fluctuations. If binaries formed in the early Universe survive to the present time, as suggested by our analytic estimates, they dominate the total PBH merger rate. Moreover, this merger rate would be orders of magnitude larger than LIGO's current upper limits if PBHs make a significant fraction of the dark matter. As a consequence, LIGO would constrain ˜10 - 300 M⊙ PBHs to constitute no more than ˜1 % of the dark matter. To make this conclusion fully robust, though, numerical study of several complex astrophysical processes—such as the formation of the first PBH halos and how they may affect PBH binaries, as well as the accretion of gas onto an extremely eccentric binary—is needed.

  15. MICROLENSING BINARIES DISCOVERED THROUGH HIGH-MAGNIFICATION CHANNEL

    Energy Technology Data Exchange (ETDEWEB)

    Shin, I.-G.; Choi, J.-Y.; Park, S.-Y.; Han, C. [Department of Physics, Institute for Astrophysics, Chungbuk National University, Cheongju 371-763 (Korea, Republic of); Gould, A.; Gaudi, B. S. [Department of Astronomy, Ohio State University, 140 W. 18th Ave., Columbus, OH 43210 (United States); Sumi, T. [Department of Earth and Space Science, Osaka University, Osaka 560-0043 (Japan); Udalski, A. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Beaulieu, J.-P. [Institut d' Astrophysique de Paris, UMR7095 CNRS-Universite Pierre and Marie Curie, 98 bis Boulevard Arago, 75014 Paris (France); Dominik, M. [School of Physics and Astronomy, SUPA, University of St. Andrews, North Haugh, St. Andrews, KY16 9SS (United Kingdom); Allen, W. [Vintage Lane Observatory, Blenheim (New Zealand); Bos, M. [Molehill Astronomical Observatory, North Shore (New Zealand); Christie, G. W. [Auckland Observatory, P.O. Box 24-180, Auckland (New Zealand); Depoy, D. L. [Department of Physics, Texas A and M University, College Station, TX (United States); Dong, S. [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States); Drummond, J. [Possum Observatory, Patutahi (New Zealand); Gal-Yam, A. [Benoziyo Center for Astrophysics, the Weizmann Institute (Israel); Hung, L.-W. [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095 (United States); Janczak, J. [Department of Physics, Ohio State University, 191 W. Woodruff, Columbus, OH 43210 (United States); Kaspi, S. [School of Physics and Astronomy, Tel-Aviv University, Tel Aviv 69978 (Israel); Collaboration: muFUN Collaboration; MOA Collaboration; OGLE Collaboration; PLANET Collaboration; RoboNet Collaboration; MiNDSTEp Consortium; and others

    2012-02-20

    Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of eight binary-lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010. The perturbations, which are confined near the peak of the light curves, can be easily distinguished from the central perturbations caused by planets. However, the degeneracy between close and wide binary solutions cannot be resolved with a 3{sigma} confidence level for three events, implying that the degeneracy would be an important obstacle in studying binary distributions. The dependence of the degeneracy on the lensing parameters is consistent with a theoretical prediction that the degeneracy becomes severe as the binary separation and the mass ratio deviate from the values of resonant caustics. The measured mass ratio of the event OGLE-2008-BLG-510/MOA-2008-BLG-369 is q {approx} 0.1, making the companion of the lens a strong brown dwarf candidate.

  16. Bursts of occipital theta and alpha amplitude preceding alternation and repetition trials in a task-switching experiment

    NARCIS (Netherlands)

    Gladwin, T.E.; De Jong, Ritske

    The instantaneous amplitude of the theta and alpha bands of the electroencephalogram (EEG) was studied during preparation periods in a task-switching experiment. Subjects had to switch between tasks in which they were to respond to either the visual or the auditory component of the stimulus. 11-13

  17. Association of single nucleotide polymorphisms in a glutamate receptor gene (GRM8) with theta power of event-related oscillations and alcohol dependence.

    Science.gov (United States)

    Chen, Andrew C H; Tang, Yongqiang; Rangaswamy, Madhavi; Wang, Jen C; Almasy, Laura; Foroud, Tatiana; Edenberg, Howard J; Hesselbrock, Victor; Nurnberger, John; Kuperman, Samuel; O'Connor, Sean J; Schuckit, Marc A; Bauer, Lance O; Tischfield, Jay; Rice, John P; Bierut, Laura; Goate, Alison; Porjesz, Bernice

    2009-04-05

    Evidence suggests the P3 amplitude of the event-related potential and its underlying superimposed event-related oscillations (EROs), primarily in the theta (4-5 Hz) and delta (1-3 Hz) frequencies, as endophenotypes for the risk of alcoholism and other disinhibitory disorders. Major neurochemical substrates contributing to theta and delta rhythms and P3 involve strong GABAergic, cholinergic and glutamatergic system interactions. The aim of this study was to test the potential associations between single nucleotide polymorphisms (SNPs) in glutamate receptor genes and ERO quantitative traits. GRM8 was selected because it maps at chromosome 7q31.3-q32.1 under the peak region where we previously identified significant linkage (peak LOD = 3.5) using a genome-wide linkage scan of the same phenotype (event-related theta band for the target visual stimuli). Neural activities recorded from scalp electrodes during a visual oddball task in which rare target elicited P3s were analyzed in a subset of the Collaborative Study on the Genetics of Alcoholism (COGA) sample comprising 1,049 Caucasian subjects from 209 families (with 472 DSM-IV alcohol dependent individuals). The family-based association test (FBAT) detected significant association (P power to target visual stimuli, and also with alcohol dependence, even after correction for multiple comparisons by false discovery rate (FDR). Our results suggest that variation in GRM8 may be involved in modulating event-related theta oscillations during information processing and also in vulnerability to alcoholism. These findings underscore the utility of electrophysiology and the endophenotype approach in the genetic study of psychiatric disorders. (c) 2008 Wiley-Liss, Inc.

  18. Gaia Assorted Mass Binaries Long Excluded from SLoWPoKES (GAMBLES): Identifying Ultra-wide Binary Pairs with Components of Diverse Mass

    Energy Technology Data Exchange (ETDEWEB)

    Oelkers, Ryan J.; Stassun, Keivan G.; Dhital, Saurav, E-mail: ryan.j.oelkers@vanderbilt.edu [Vanderbilt University, Department of Physics and Astronomy, Nashville, TN 37235 (United States)

    2017-06-01

    The formation and evolution of binary star systems are some of the remaining key questions in modern astronomy. Wide binary pairs (separations >10{sup 3} au) are particularly intriguing because their low binding energies make it difficult for the stars to stay gravitationally bound over extended timescales, and thus to probe the dynamics of binary formation and dissolution. Our previous SLoWPoKES catalogs, I and II, provided the largest and most complete sample of wide-binary pairs of low masses. Here we present an extension of these catalogs to a broad range of stellar masses: the Gaia Assorted Mass Binaries Long Excluded from SloWPoKES (GAMBLES), comprising 8660 statistically significant wide pairs that we make available in a living online database. Within this catalog we identify a subset of 543 long-lived (dissipation timescale >1.5 Gyr) candidate binary pairs, of assorted mass, with typical separations between 10{sup 3} and 10{sup 5.5} au (0.002–1.5 pc), using the published distances and proper motions from the Tycho -Gaia Astrometric Solution and Sloan Digital Sky Survey photometry. Each pair has at most a false positive probability of 0.05; the total expectation is 2.44 false binaries in our sample. Among these, we find 22 systems with 3 components, 1 system with 4 components, and 15 pairs consisting of at least 1 possible red giant. We find the largest long-lived binary separation to be nearly 3.2 pc; even so, >76% of GAMBLES long-lived binaries have large binding energies and dissipation lifetimes longer than 1.5 Gyr. Finally, we find that the distribution of binary separations is clearly bimodal, corroborating the findings from SloWPoKES and suggesting multiple pathways for the formation and dissipation of the widest binaries in the Galaxy.

  19. Gaia Assorted Mass Binaries Long Excluded from SLoWPoKES (GAMBLES): Identifying Ultra-wide Binary Pairs with Components of Diverse Mass

    International Nuclear Information System (INIS)

    Oelkers, Ryan J.; Stassun, Keivan G.; Dhital, Saurav

    2017-01-01

    The formation and evolution of binary star systems are some of the remaining key questions in modern astronomy. Wide binary pairs (separations >10 3 au) are particularly intriguing because their low binding energies make it difficult for the stars to stay gravitationally bound over extended timescales, and thus to probe the dynamics of binary formation and dissolution. Our previous SLoWPoKES catalogs, I and II, provided the largest and most complete sample of wide-binary pairs of low masses. Here we present an extension of these catalogs to a broad range of stellar masses: the Gaia Assorted Mass Binaries Long Excluded from SloWPoKES (GAMBLES), comprising 8660 statistically significant wide pairs that we make available in a living online database. Within this catalog we identify a subset of 543 long-lived (dissipation timescale >1.5 Gyr) candidate binary pairs, of assorted mass, with typical separations between 10 3 and 10 5.5 au (0.002–1.5 pc), using the published distances and proper motions from the Tycho -Gaia Astrometric Solution and Sloan Digital Sky Survey photometry. Each pair has at most a false positive probability of 0.05; the total expectation is 2.44 false binaries in our sample. Among these, we find 22 systems with 3 components, 1 system with 4 components, and 15 pairs consisting of at least 1 possible red giant. We find the largest long-lived binary separation to be nearly 3.2 pc; even so, >76% of GAMBLES long-lived binaries have large binding energies and dissipation lifetimes longer than 1.5 Gyr. Finally, we find that the distribution of binary separations is clearly bimodal, corroborating the findings from SloWPoKES and suggesting multiple pathways for the formation and dissipation of the widest binaries in the Galaxy.

  20. Is the hippocampal theta rhythm related to cognition in a non-locomotor place recognition task?

    Czech Academy of Sciences Publication Activity Database

    Kelemen, Edo; Morón, I.; Fenton, André Antonio

    2005-01-01

    Roč. 15, č. 4 (2005), s. 472-479 ISSN 1050-9631 Grant - others:5th Framework Development Program(XE) QLG3-CT-1999-00192; McDonnell Foundation(US) 98-38-CNS-QUA.05; Ministerio de Ciencia y Tecnologia (ES) BS02002-01215 Institutional research plan: CEZ:AV0Z5011922 Keywords : theta rhythm * cognition * place recognition Subject RIV: FH - Neurology Impact factor: 3.781, year: 2005

  1. Binary and ternary systems

    International Nuclear Information System (INIS)

    Petrov, D.A.

    1986-01-01

    Conditions for thermodynamical equilibrium in binary and ternary systems are considered. Main types of binary and ternary system phase diagrams are sequently constructed on the basis of general regularities on the character of transition from one equilibria to others. New statements on equilibrium line direction in the diagram triple points and their isothermal cross sections are developed. New represenations on equilibria in case of monovariant curve minimum and maximum on three-phase equilibrium formation in ternary system are introduced

  2. Planet formation in Binaries

    OpenAIRE

    Thebault, Ph.; Haghighipour, N.

    2014-01-01

    Spurred by the discovery of numerous exoplanets in multiple systems, binaries have become in recent years one of the main topics in planet formation research. Numerous studies have investigated to what extent the presence of a stellar companion can affect the planet formation process. Such studies have implications that can reach beyond the sole context of binaries, as they allow to test certain aspects of the planet formation scenario by submitting them to extreme environments. We review her...

  3. Non-negative Matrix Factorization for Binary Data

    DEFF Research Database (Denmark)

    Larsen, Jacob Søgaard; Clemmensen, Line Katrine Harder

    We propose the Logistic Non-negative Matrix Factorization for decomposition of binary data. Binary data are frequently generated in e.g. text analysis, sensory data, market basket data etc. A common method for analysing non-negative data is the Non-negative Matrix Factorization, though...... this is in theory not appropriate for binary data, and thus we propose a novel Non-negative Matrix Factorization based on the logistic link function. Furthermore we generalize the method to handle missing data. The formulation of the method is compared to a previously proposed method (Tome et al., 2015). We compare...... the performance of the Logistic Non-negative Matrix Factorization to Least Squares Non-negative Matrix Factorization and Kullback-Leibler (KL) Non-negative Matrix Factorization on sets of binary data: a synthetic dataset, a set of student comments on their professors collected in a binary term-document matrix...

  4. Binary and Millisecond Pulsars.

    Science.gov (United States)

    Lorimer, Duncan R

    2008-01-01

    We review the main properties, demographics and applications of binary and millisecond radio pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1800. There are now 83 binary and millisecond pulsars associated with the disk of our Galaxy, and a further 140 pulsars in 26 of the Galactic globular clusters. Recent highlights include the discovery of the young relativistic binary system PSR J1906+0746, a rejuvination in globular cluster pulsar research including growing numbers of pulsars with masses in excess of 1.5 M ⊙ , a precise measurement of relativistic spin precession in the double pulsar system and a Galactic millisecond pulsar in an eccentric ( e = 0.44) orbit around an unevolved companion. Supplementary material is available for this article at 10.12942/lrr-2008-8.

  5. Flip-flopping binary black holes.

    Science.gov (United States)

    Lousto, Carlos O; Healy, James

    2015-04-10

    We study binary spinning black holes to display the long term individual spin dynamics. We perform a full numerical simulation starting at an initial proper separation of d≈25M between equal mass holes and evolve them down to merger for nearly 48 orbits, 3 precession cycles, and half of a flip-flop cycle. The simulation lasts for t=20 000M and displays a total change in the orientation of the spin of one of the black holes from an initial alignment with the orbital angular momentum to a complete antialignment after half of a flip-flop cycle. We compare this evolution with an integration of the 3.5 post-Newtonian equations of motion and spin evolution to show that this process continuously flip flops the spin during the lifetime of the binary until merger. We also provide lower order analytic expressions for the maximum flip-flop angle and frequency. We discuss the effects this dynamics may have on spin growth in accreting binaries and on the observational consequences for galactic and supermassive binary black holes.

  6. Study of flow and loss processes at the ends of a linear theta pinch. Progress report, June 1, 1978--May 31, 1979

    International Nuclear Information System (INIS)

    York, T.M.; Klevans, E.H.

    1979-02-01

    Experimental and analytical studies of end loss from a linear theta pinch have been carried out. Analysis of reduced data on loss from a 25 cm long theta pinch has indicated: rotation at the end of pinch collapse, which appears to persist; ejection of the plasma in two modes, the first of which includes reversed, trapped fields; unique patterns of radial and axial variation of electron density in the end loss flow; substantial inaccuracies in plasma properties indicated by spectroscopy as compared to Thomson scattering. Studies of loss in a 50 cm long pinch with 50 eV, 2 x 10 16 cm -3 plasma are underway

  7. Phase precession through acceleration of local theta rhythm: a biophysical model for the interaction between place cells and local inhibitory neurons.

    Science.gov (United States)

    Castro, Luísa; Aguiar, Paulo

    2012-08-01

    Phase precession is one of the most well known examples within the temporal coding hypothesis. Here we present a biophysical spiking model for phase precession in hippocampal CA1 which focuses on the interaction between place cells and local inhibitory interneurons. The model's functional block is composed of a place cell (PC) connected with a local inhibitory cell (IC) which is modulated by the population theta rhythm. Both cells receive excitatory inputs from the entorhinal cortex (EC). These inputs are both theta modulated and space modulated. The dynamics of the two neuron types are described by integrate-and-fire models with conductance synapses, and the EC inputs are described using non-homogeneous Poisson processes. Phase precession in our model is caused by increased drive to specific PC/IC pairs when the animal is in their place field. The excitation increases the IC's firing rate, and this modulates the PC's firing rate such that both cells precess relative to theta. Our model implies that phase coding in place cells may not be independent from rate coding. The absence of restrictive connectivity constraints in this model predicts the generation of phase precession in any network with similar architecture and subject to a clocking rhythm, independently of the involvement in spatial tasks.

  8. Binary Star Fractions from the LAMOST DR4

    Science.gov (United States)

    Tian, Zhi-Jia; Liu, Xiao-Wei; Yuan, Hai-Bo; Chen, Bing-Qiu; Xiang, Mao-Sheng; Huang, Yang; Wang, Chun; Zhang, Hua-Wei; Guo, Jin-Cheng; Ren, Juan-Juan; Huo, Zhi-Ying; Yang, Yong; Zhang, Meng; Bi, Shao-Lan; Yang, Wu-Ming; Liu, Kang; Zhang, Xian-Fei; Li, Tan-Da; Wu, Ya-Qian; Zhang, Jing-Hua

    2018-05-01

    Stellar systems composed of single, double, triple or higher-order systems are rightfully regarded as the fundamental building blocks of the Milky Way. Binary stars play an important role in formation and evolution of the Galaxy. Through comparing the radial velocity variations from multi-epoch observations, we analyze the binary fraction of dwarf stars observed with LAMOST. Effects of different model assumptions, such as orbital period distributions on the estimate of binary fractions, are investigated. The results based on log-normal distribution of orbital periods reproduce the previous complete analyses better than the power-law distribution. We find that the binary fraction increases with T eff and decreases with [Fe/H]. We first investigate the relation between α-elements and binary fraction in such a large sample as provided by LAMOST. The old stars with high [α/Fe] dominate with a higher binary fraction than young stars with low [α/Fe]. At the same mass, earlier forming stars possess a higher binary fraction than newly forming ones, which may be related with evolution of the Galaxy.

  9. Protozoarios parásitos de importancia en salud pública transportados por Musca domestica Linnaeus en Lima, Perú

    Directory of Open Access Journals (Sweden)

    Martín Cárdenas

    2013-06-01

    Full Text Available El presente trabajo investiga los protozoarios parásitos de importancia para la salud pública transportados por Musca domestica. El estudio se llevó a cabo entre los meses de junio y diciembre de 1998, en los distritos de Comas y San Juan de Lurigancho de la provincia de Lima. Se estudiaron 3014 moscas colectadas en la basura acumulada en la vía pública de los pueblos jóvenes de los distritos mencionados. Las capturas se agruparon en lotes constituidos por un promedio de 30 moscas. Se estudiaron un total de 100 lotes. Las moscas fueron disecadas y procesadas con agua destilada estéril para obtener un macerado intestinal. Para la observación de los parásitos se utilizó el método directo simple y la coloración tricrómica de Gomori ácido resistente modificado. Se encontraron los siguientes protozoarios que parasitan al hombre: Blastocystis hominis (9,0%, Giardia lamblia (3,0%, Cryptosporidium sp. (2,0%, Cyclospora cayetanensis (1,0%, Iodamoeba bütschlii (17,0%, Endolimax nana (5,0% y Chilomastix mesnili (3,0%. Se reporta por primera vez para el Perú a B. hominis y Cyclospora cayetanensis en M. domestica.

  10. WHITE-LIGHT FLARES ON CLOSE BINARIES OBSERVED WITH KEPLER

    International Nuclear Information System (INIS)

    Gao, Qing; Xin, Yu; Liu, Ji-Feng; Zhang, Xiao-Bin; Gao, Shuang

    2016-01-01

    Based on Kepler data, we present the results of a search for white light flares on 1049 close binaries. We identify 234 flare binaries, of which 6818 flares are detected. We compare the flare-binary fraction in different binary morphologies (“detachedness”). The result shows that the fractions in over-contact and ellipsoidal binaries are approximately 10%–20% lower than those in detached and semi-detached systems. We calculate the binary flare activity level (AL) of all the flare binaries, and discuss its variations along the orbital period ( P orb ) and rotation period ( P rot , calculated for only detached binaries). We find that the AL increases with decreasing P orb or P rot , up to the critical values at P orb ∼ 3 days or P rot ∼ 1.5 days, and thereafter the AL starts decreasing no matter how fast the stars rotate. We examine the flaring rate as a function of orbital phase in two eclipsing binaries on which a large number of flares are detected. It appears that there is no correlation between flaring rate and orbital phase in these two binaries. In contrast, when we examine the function with 203 flares on 20 non-eclipse ellipsoidal binaries, bimodal distribution of amplitude-weighted flare numbers shows up at orbital phases 0.25 and 0.75. Such variation could be larger than what is expected from the cross section modification.

  11. Reduction in LFP cross-frequency coupling between theta and gamma rhythms associated with impaired STP and LTP in a rat model of brain ischemia

    Directory of Open Access Journals (Sweden)

    Tao eZhang

    2013-04-01

    Full Text Available The theta-gamma cross-frequency coupling (CFC in hippocampus was reported to reflect memory process. In this study, we measured the CFC of hippocampal local field potentials (LFPs in a two-vessel occlusion (2VO rat model, combined with both amplitude and phase properties and associated with short and long-term plasticity indicating the memory function. Male Wistar rats were used and a 2VO model was established. STP and LTP were recorded in hippocampal CA3-CA1 pathway after LFPs were collected in both CA3 and CA1. Based on the data of relative power spectra and phase synchronization, it suggested that both the amplitude and phase coupling of either theta or gamma rhythm were involved in modulating the neural network in 2VO rats. In order to determine whether the CFC was also implicated in neural impairment in 2VO rats, the coupling of CA3 theta–CA1 gamma was measured by both phase-phase coupling (n:m phase synchronization and phase-amplitude coupling. The attenuated CFC strength in 2VO rats implied the impaired neural communication in the coordination of theta-gamma entraining process. Moreover, compared with modulation index (MI a novel algorithm named cross frequency conditional mutual information (CF-CMI, was developed to focus on the coupling between theta phase and the phase of gamma amplitude. The results suggest that the reduced CFC strength probably attributed to the disruption of the phase of CA1 gamma envelop. In conclusion, it implied that the phase coupling and CFC of hippocampal theta and gamma played an important role in supporting functions of neural network. Furthermore, synaptic plasticity on CA3-CA1 pathway was reduced in line with the decreased CFC strength from CA3 to CA1. It partly supported our hypothesis that directional CFC indicator might probably be used as a measure of synaptic plasticity.

  12. Evolution and merging of binaries with compact objects

    International Nuclear Information System (INIS)

    Bethe, Hans A.; Brown, Gerald E.; Lee, Chang-Hwan

    2007-01-01

    In the light of recent observations in which short γ-ray bursts are interpreted as arising from black-hole(BH), neutron-star(NS) or NS-NS mergings we would like to review our research on the evolution of compact binaries, especially those containing NS's. These were carried out with predictions for LIGO in mind, but are directly applicable to short γ-ray bursts in the interpretation above. Most important in our review is that we show that the standard scenario for evolving NS-NS binaries always ends up with a low-mass BH (LMBH), NS binary. Bethe and Brown [1998, Astrophys. J. 506, 780] showed that this fate could be avoided if the two giants in the progenitor binary burned He at the same time, and that in this way the binary could avoid the common envelope evolution of the NS with red giant companion which sends the first born NS into a BH in the standard scenario. The burning of He at the same time requires, for the more massive giants such as the progenitors of the Hulse-Taylor binary NS that the two giants be within 4% of each other in zero age main sequence (ZAMS) mass. Applying this criterion to all binaries results in a factor ∼5 of LMBH-NS binaries as compared with NS-NS binaries. Although this factor is substantially less than the originally claimed factor of 20 which Bethe and Brown (1998) estimated, largely because a careful evolution has been carried through here, our factor 5 is augmented by a factor of ∼8 arising from the higher rate of star formation in the earlier Galaxy from which the BH-NS binaries came from. Furthermore, here we calculate the mergers for short-hard gamma-ray bursts, whereas Bethe and Brown's factor 20 included a factor of 2 for the higher chirp masses in a BH-NS binary as compared with NS-NS one. In short, we end up with an estimate of factor ∼40 over that calculated with NS-NS binary mergers in our Galaxy alone. Our total rate is estimated to be about one merging of compact objects per year. Our scenario of NS-NS binaries

  13. Rotational properties of the binary and non-binary populations in the Trans-Neptunian belt

    Science.gov (United States)

    Thirouin, Audrey; Noll, Keith S.; Ortiz Moreno, Jose Luis; Morales , Nicolas

    2014-11-01

    An exhaustive study about short-term variability as well as derived properties from lightcurves allowed us to draw some conclusions for the Trans-Neptunian belt binary population. Based on Maxwellian fit distributions of the spin rate, we suggested that the binary population rotates slower than the non-binary one. This slowing-down can be attributed to tidal effects between the satellite and the primary, as expected. We showed that no system in this work is tidally locked, but the primary despinning process may have already affected the primary rate (as well as the satellite rotational rate). We used the Gladman et al. (1996) formula to compute the time required to tidally lock the systems, but this formula is based on several assumptions and approximations that do not always hold. The computed times are reasonable in most cases and confirm that none of the systems is tidally locked, assuming that the satellite densities are low and have a high rigidity or have a higher dissipation than usually assumed. The rotational properties of small bodies provide information about important physical properties, such as shape, density, and cohesion (Pravec & Harris 2000; Holsapple 2001, 2004; Thirouin et al. 2010, 2012). For binaries it is also possible to derive several physical parameters of the system components, such as diameters of the primary/secondary and albedo under some assumptions. We compare our results as well as our technique for deriving this information from the lightcurve with other methods, such as: i) thermal or thermophysical modeling, ii) from the mutual orbit of the binary component, iii) from direct imaging or iv) from stellar occultation by Trans-Neptunian Objects (TNOs). Finally, by studying the specific angular momentum of the sample, we proposed possible formation models for several binary TNOs. In several cases, we obtained hints of the formation mechanism from the angular momentum, but for other cases we do not have enough information about the

  14. Texture classification by texton: statistical versus binary.

    Directory of Open Access Journals (Sweden)

    Zhenhua Guo

    Full Text Available Using statistical textons for texture classification has shown great success recently. The maximal response 8 (Statistical_MR8, image patch (Statistical_Joint and locally invariant fractal (Statistical_Fractal are typical statistical texton algorithms and state-of-the-art texture classification methods. However, there are two limitations when using these methods. First, it needs a training stage to build a texton library, thus the recognition accuracy will be highly depended on the training samples; second, during feature extraction, local feature is assigned to a texton by searching for the nearest texton in the whole library, which is time consuming when the library size is big and the dimension of feature is high. To address the above two issues, in this paper, three binary texton counterpart methods were proposed, Binary_MR8, Binary_Joint, and Binary_Fractal. These methods do not require any training step but encode local feature into binary representation directly. The experimental results on the CUReT, UIUC and KTH-TIPS databases show that binary texton could get sound results with fast feature extraction, especially when the image size is not big and the quality of image is not poor.

  15. Absolute Dimensions of Contact Binary Stars in Baade Window

    Directory of Open Access Journals (Sweden)

    Young Woon Kang

    1999-12-01

    Full Text Available The light curves of the representative 6 contact binary stars observed by OGLE Project of searching for dark matter in our Galaxy have been analyzed by the method of the Wilson and Devinney Differential Correction to find photometric solutions. The orbital inclinations of these binaries are in the range of 52 deg - 69 deg which is lower than that of the solar neighborhood binaries. The Roche lobe filling factor of these binaries are distributed in large range of 0.12 - 0.90. Since absence of spectroscopic observations for these binaries we have found masses of the 6 binary systems based on the intersection between Kepler locus and locus derived from Vandenberg isochrones in the mass - luminosity plane. Then absolute dimensions and distances have been found by combining the masses and the photometric solutions. The distances of the 6 binary systems are distributed in the range of 1 kpc - 6 kpc. This distance range is the limiting range where the contact binaries which have period shorter than a day are visible. Most contact binaries discovered in the Baade window do not belong to the Galactic bulge.

  16. Orbital motion in pre-main sequence binaries

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, G. H. [The CHARA Array of Georgia State University, Mount Wilson Observatory, Mount Wilson, CA 91023 (United States); Prato, L. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Simon, M. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States); Patience, J., E-mail: schaefer@chara-array.org [Astrophysics Group, School of Physics, University of Exeter, Exeter, EX4 4QL (United Kingdom)

    2014-06-01

    We present results from our ongoing program to map the visual orbits of pre-main sequence (PMS) binaries in the Taurus star forming region using adaptive optics imaging at the Keck Observatory. We combine our results with measurements reported in the literature to analyze the orbital motion for each binary. We present preliminary orbits for DF Tau, T Tau S, ZZ Tau, and the Pleiades binary HBC 351. Seven additional binaries show curvature in their relative motion. Currently, we can place lower limits on the orbital periods for these systems; full solutions will be possible with more orbital coverage. Five other binaries show motion that is indistinguishable from linear motion. We suspect that these systems are bound and might show curvature with additional measurements in the future. The observations reported herein lay critical groundwork toward the goal of measuring precise masses for low-mass PMS stars.

  17. Binary catalogue of exoplanets

    Science.gov (United States)

    Schwarz, Richard; Bazso, Akos; Zechner, Renate; Funk, Barbara

    2016-02-01

    Since 1995 there is a database which list most of the known exoplanets (The Extrasolar Planets Encyclopaedia at http://exoplanet.eu/). With the growing number of detected exoplanets in binary and multiple star systems it became more important to mark and to separate them into a new database, which is not available in the Extrasolar Planets Encyclopaedia. Therefore we established an online database (which can be found at: http://www.univie.ac.at/adg/schwarz/multiple.html) for all known exoplanets in binary star systems and in addition for multiple star systems, which will be updated regularly and linked to the Extrasolar Planets Encyclopaedia. The binary catalogue of exoplanets is available online as data file and can be used for statistical purposes. Our database is divided into two parts: the data of the stars and the planets, given in a separate list. We describe also the different parameters of the exoplanetary systems and present some applications.

  18. Serial binary interval ratios improve rhythm reproduction

    Directory of Open Access Journals (Sweden)

    Xiang eWu

    2013-08-01

    Full Text Available Musical rhythm perception is a natural human ability that involves complex cognitive processes. Rhythm refers to the organization of events in time, and musical rhythms have an underlying hierarchical metrical structure. The metrical structure induces the feeling of a beat and the extent to which a rhythm induces the feeling of a beat is referred to as its metrical strength. Binary ratios are the most frequent interval ratio in musical rhythms. Rhythms with hierarchical binary ratios are better discriminated and reproduced than rhythms with hierarchical non-binary ratios. However, it remains unclear whether a superiority of serial binary over non-binary ratios in rhythm perception and reproduction exists. In addition, how different types of serial ratios influence the metrical strength of rhythms remains to be elucidated. The present study investigated serial binary vs. non-binary ratios in a reproduction task. Rhythms formed with exclusively binary (1:2:4:8, non-binary integer (1:3:5:6, and non-integer (1:2.3:5.3:6.4 ratios were examined within a constant meter. The results showed that the 1:2:4:8 rhythm type was more accurately reproduced than the 1:3:5:6 and 1:2.3:5.3:6.4 rhythm types, and the 1:2.3:5.3:6.4 rhythm type was more accurately reproduced than the 1:3:5:6 rhythm type. Further analyses showed that reproduction performance was better predicted by the distribution pattern of event occurrences within an inter-beat interval, than by the coincidence of events with beats, or the magnitude and complexity of interval ratios. Whereas rhythm theories and empirical data emphasize the role of the coincidence of events with beats in determining metrical strength and predicting rhythm performance, the present results suggest that rhythm processing may be better understood when the distribution pattern of event occurrences is taken into account. These results provide new insights into the mechanisms underlining musical rhythm perception.

  19. Serial binary interval ratios improve rhythm reproduction.

    Science.gov (United States)

    Wu, Xiang; Westanmo, Anders; Zhou, Liang; Pan, Junhao

    2013-01-01

    Musical rhythm perception is a natural human ability that involves complex cognitive processes. Rhythm refers to the organization of events in time, and musical rhythms have an underlying hierarchical metrical structure. The metrical structure induces the feeling of a beat and the extent to which a rhythm induces the feeling of a beat is referred to as its metrical strength. Binary ratios are the most frequent interval ratio in musical rhythms. Rhythms with hierarchical binary ratios are better discriminated and reproduced than rhythms with hierarchical non-binary ratios. However, it remains unclear whether a superiority of serial binary over non-binary ratios in rhythm perception and reproduction exists. In addition, how different types of serial ratios influence the metrical strength of rhythms remains to be elucidated. The present study investigated serial binary vs. non-binary ratios in a reproduction task. Rhythms formed with exclusively binary (1:2:4:8), non-binary integer (1:3:5:6), and non-integer (1:2.3:5.3:6.4) ratios were examined within a constant meter. The results showed that the 1:2:4:8 rhythm type was more accurately reproduced than the 1:3:5:6 and 1:2.3:5.3:6.4 rhythm types, and the 1:2.3:5.3:6.4 rhythm type was more accurately reproduced than the 1:3:5:6 rhythm type. Further analyses showed that reproduction performance was better predicted by the distribution pattern of event occurrences within an inter-beat interval, than by the coincidence of events with beats, or the magnitude and complexity of interval ratios. Whereas rhythm theories and empirical data emphasize the role of the coincidence of events with beats in determining metrical strength and predicting rhythm performance, the present results suggest that rhythm processing may be better understood when the distribution pattern of event occurrences is taken into account. These results provide new insights into the mechanisms underlining musical rhythm perception.

  20. BHDD: Primordial black hole binaries code

    Science.gov (United States)

    Kavanagh, Bradley J.; Gaggero, Daniele; Bertone, Gianfranco

    2018-06-01

    BHDD (BlackHolesDarkDress) simulates primordial black hole (PBH) binaries that are clothed in dark matter (DM) halos. The software uses N-body simulations and analytical estimates to follow the evolution of PBH binaries formed in the early Universe.