Liquid Phase Deposition of Single-Phase Alpha-Copper-Indium-Diselenide

Science.gov (United States)

Hepp, Aloysius F.; Bailey, S.; Cowen, Jonathan; Lucas, L.; Ernst, Frank; Pirouz, P.

2004-01-01

The success of exploratory missions in outer space often depends on a highly efficient renewable energy supply, as provided by solar cells. Since future missions will demand large aggregates of solar cells, and space flight is expensive, the solar cells must furthermore be available at low costs and have a long lifetime and high resistance against structural damage introduced by irradiation with high energy electrons and protons. The photovoltaic materials that are presently available only partly fulfill all these requirements. Therefore, we propose to explore a new method for fabricating thin-films for cost-efficient solar cells with very high specific power,high irradiation resistance and long lifetime based on the alpha-phase of the Cu-In-Se system "alpha-CIS."

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....

Foil deposition alpha collector probe for TFTR's D-T phase

International Nuclear Information System (INIS)

Hermann, H.W.; Darrow, D.S.; Timberlake, J.; Zweben, S.J.; Chong, G.P.; Pitcher, C.S.; Macaulay-Newcombe, R.G.

1995-03-01

A new foil deposition alpha collector sample probe has been developed for TFTR's D-T phase. D-T fusion produced alpha particles escaping from the plasma are implanted in nickel foils located in a series of collimating ports on the detector. The nickel foils are removed from the tokamak after exposure to one or more plasma discharges and analyzed for helium content. This detector is intended to provide improved alpha particle energy resolution and pitch angle coverage over existing lost alpha detectors, and to provide an absolutely calibrated cross-check with these detectors. The ability to resolve between separate energy components of alpha particle loss is estimated to be ∼ 20%. A full 360 degree of pitch angle coverage is provided for by 8 channels having an acceptance range of ∼ 53 degree per channel. These detectors will be useful in characterizing classical and anomalous alpha losses and any collective alpha instabilities that may be excited during the D-T campaign of TFTR

Microstructure and phase morphology during thermochemical processing of {alpha}{sub 2}-based titanium aluminide castings

Energy Technology Data Exchange (ETDEWEB)

Saqib, M. [Wright State Univ., Dayton, OH (United States). Dept. of Mechanical and Materials Engineering; Apgar, L.S. [Dayton Univ., OH (United States). Graduate Materials Engineering; Eylon, D. [Dayton Univ., OH (United States). Graduate Materials Engineering; Weiss, I. [Wright State Univ., Dayton, OH (United States). Dept. of Mechanical and Materials Engineering

1995-12-31

Changes in the microstructure, volume fraction and distribution of phases during different stages of thermochemical processing of Ti-25Al-10Nb-3V-1Mo (at.%) castings were investigated. Up to 14.5 at.% (0.35 wt.%) of hydrogen was introduced into the material by gas charging at temperatures between 650 and 980 C for times up to 20 h. The material was subsequently dehydrogenated by vacuum annealing at 650 C for 48 h. Investment cast Ti-25Al-10Nb-3V-1Mo alloy, hot isostatically pressed (HIP) at 1175 C at 260 MPa for 6 h, was used as the starting material. The microstructure of the as-HIP material consists of {alpha}{sub 2}, B2 and orthorhombic phases. The {alpha}{sub 2} phase exists in equiaxed, Widmanstaeten and cellular morphologies. The B2 phase is observed mainly along {alpha}{sub 2}/{alpha}{sub 2} boundaries. Some {alpha}{sub 2} Widmanstaeten also contain very fine orthorhombic phase in a plate-like morphology. Hydrogenation of the material modified the microstructure; however, the morphology of the {alpha}{sub 2} and B2 phases did not change. Furthermore, hydride precipitation and a higher volume fraction of the orthorhombic phase were observed compared with the as-HIP material. Following dehydrogenation, the hydrogen level in the material was found to be less than 0.1 at.% (0.0025wt.%). Transmission electron microscopy of the dehydrogenated material did not reveal the presence of hydride precipitates; however, the high volume fraction of the orthorhombic phase was found to persist following dehydrogenation. (orig.)

Predictability of depression severity based on posterior alpha oscillations.

Science.gov (United States)

Jiang, H; Popov, T; Jylänki, P; Bi, K; Yao, Z; Lu, Q; Jensen, O; van Gerven, M A J

2016-04-01

We aimed to integrate neural data and an advanced machine learning technique to predict individual major depressive disorder (MDD) patient severity. MEG data was acquired from 22 MDD patients and 22 healthy controls (HC) resting awake with eyes closed. Individual power spectra were calculated by a Fourier transform. Sources were reconstructed via beamforming technique. Bayesian linear regression was applied to predict depression severity based on the spatial distribution of oscillatory power. In MDD patients, decreased theta (4-8 Hz) and alpha (8-14 Hz) power was observed in fronto-central and posterior areas respectively, whereas increased beta (14-30 Hz) power was observed in fronto-central regions. In particular, posterior alpha power was negatively related to depression severity. The Bayesian linear regression model showed significant depression severity prediction performance based on the spatial distribution of both alpha (r=0.68, p=0.0005) and beta power (r=0.56, p=0.007) respectively. Our findings point to a specific alteration of oscillatory brain activity in MDD patients during rest as characterized from MEG data in terms of spectral and spatial distribution. The proposed model yielded a quantitative and objective estimation for the depression severity, which in turn has a potential for diagnosis and monitoring of the recovery process. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

On the rutile alpha-PbO"2-type phase boundary of TiO"2

DEFF Research Database (Denmark)

Olsen, J.S.; Gerward, Leif; Jiang, Jianzhong

1999-01-01

The high-pressure, high-temperature phase quilibria of TiO"2 have been studied with special emphasis on the rutile and alpha-PbO"2-type phases. It is found that the phase boundary, when plotted in a pressure-temperature diagram, changes from having a negative to having a positive slope...... with increasing temperature at about 6GPa and 850^oC. For nanophase material, the phase boundary is shifted towards lower pressure. The room-temperature bulk moduli are 210(120)GPa, 258(8)GPa and 290(20)GPa for rutile, the alpha-PbO"2-type phase and the baddeleyite-type phase, respectively....

Resting state alpha frequency is associated with menstrual cycle phase, estradiol and use of oral contraceptives.

Science.gov (United States)

Brötzner, Christina P; Klimesch, Wolfgang; Doppelmayr, Michael; Zauner, Andrea; Kerschbaum, Hubert H

2014-08-19

Ongoing intrinsic brain activity in resting, but awake humans is dominated by alpha oscillations. In human, individual alpha frequency (IAF) is associated with cognitive performance. Noticeable, performance in cognitive and emotional tasks in women is associated with menstrual cycle phase and sex hormone levels, respectively. In the present study, we correlated frequency of alpha oscillation in resting women with menstrual cycle phase, sex hormone level, or use of oral contraceptives. Electroencephalogram (EEG) was recorded from 57 women (aged 24.07 ± 3.67 years) having a natural menstrual cycle as well as from 57 women (aged 22.37 ± 2.20 years) using oral contraceptives while they sat in an armchair with eyes closed. Alpha frequency was related to the menstrual cycle phase. Luteal women showed highest and late follicular women showed lowest IAF or center frequency. Furthermore, IAF as well as center frequency correlated negatively with endogenous estradiol level, but did not reveal an association with endogenous progesterone. Women using oral contraceptives showed an alpha frequency similar to women in the early follicular phase. We suggest that endogenous estradiol modulate resting alpha frequency. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Resting state alpha frequency is associated with menstrual cycle phase, estradiol and use of oral contraceptives

OpenAIRE

Brötzner, Christina P.; Klimesch, Wolfgang; Doppelmayr, Michael; Zauner, Andrea; Kerschbaum, Hubert H.

2014-01-01

Ongoing intrinsic brain activity in resting, but awake humans is dominated by alpha oscillations. In human, individual alpha frequency (IAF) is associated with cognitive performance. Noticeable, performance in cognitive and emotional tasks in women is associated with menstrual cycle phase and sex hormone levels, respectively. In the present study, we correlated frequency of alpha oscillation in resting women with menstrual cycle phase, sex hormone level, or use of oral contraceptives. Electro...

Neutron Diffraction Study On Gamma To Alpha Phase Transition In Ce0.9th0.1 Alloy

Energy Technology Data Exchange (ETDEWEB)

Lashley, Jason C1 [Los Alamos National Laboratory; Heffner, Robert H [Los Alamos National Laboratory; Llobet, A [Los Alamos National Laboratory; Darling, T W [U OF NEVADA; Jeong, I K [PUSAN NATL UNIV

2008-01-01

Comprehensive neutron diffraction measurements were performed to study the isostructural {gamma} {leftrightarrow} {alpha} phase transition in Ce{sub 0.9}Th{sub 0.1} alloy. Using Rietveld refinements, we obtained lattice and thermal parameters as a function of temperature. From the temperature slope of the thermal parameters, we determined Debye temperatures {Theta}{sup {gamma}}{sub D} = 133(1) K and {Theta}{sup {alpha}}{sub D} = 140(1) K for the {gamma} phase and the {alpha} phase, respectively. This result implies that the vibrational entropy change is not significant at the {gamma} {leftrightarrow} {alpha} transition, contrary to that from elemental Cerium [Phys. Rev. Lett. 92, 105702, 2004].

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.

S-matrix to potential inversion of low-energy. alpha. - sup 12 C phase shifts

Energy Technology Data Exchange (ETDEWEB)

Cooper, S.G.; Mackintosh, R.S. (Open Univ., Milton Keynes (UK). Dept. of Physics)

1990-10-22

The IP S-matrix to potential inversion procedure is applied to phase shifts for selected partial waves over a range of energies below the inelastic threshold for {alpha}-{sup 12}C scattering. The phase shifts were determined by Plaga et al. Potentials found by Buck and Rubio to fit the low-energy alpha cluster resonances need only an increased attraction in the surface to accurately reproduce the phase-shift behaviour. Substantial differences between the potentials for odd and even partial waves are necessary. The surface tail of the potential is postulated to be a threshold effect. (orig.).

Alpha-driven magnetohydrodynamics (MHD) and MHD-induced alpha loss in the Tokamak Fusion Test Reactor

International Nuclear Information System (INIS)

Chang, Z.; Nazikian, R.; Fu, G.Y.

1997-02-01

Alpha-driven toroidal Alfven eigenmodes (TAEs) are observed as predicted by theory in the post neutral beam phase in high central q (safety factor) deuterium-tritium (D-T) plasmas in the Tokamak Fusion Test Reactor (TFTR). The mode location, poloidal structure and the importance of q profile for TAE instability are discussed. So far no alpha particle loss due to these modes was detected due to the small mode amplitude. However, alpha loss induced by kinetic ballooning modes (KBMs) was observed in high confinement D-T discharges. Particle orbit simulation demonstrates that the wave-particle resonant interaction can explain the observed correlation between the increase in alpha loss and appearance of multiple high-n (n ≥ 6, n is the toroidal mode number) modes

Microstructural analysis of the {delta} to {alpha}' phase transformation in plutonium alloys using X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Platteau, C; Ravat, B; Texier, G; Oudot, B; Delaunay, F, E-mail: brice.ravat@cea.fr [CEA Valduc 21120 Is sur Tille (France)

2010-03-15

The partial martensitic {delta}{yields}{alpha}' transformation in plutonium alloys is sensitive to chemical composition, sample thermal history, as well as crystalline defects. The present work investigates the {delta}-Pu phase microstructure before and after the martensitic transformation {delta}{yields}{delta}+{alpha}'. More precisely, microstructural modifications of the host {delta}-phase, resulting from the stress induced by a cell volume difference of 19% between the {delta} and {alpha}'-phases, were analysed. Microstructural information about crystallite size and microstrain of a highly homogenized Pu-Ga alloy was extracted from x-ray diffraction patterns using a three dimension crystallite size and microstrain model. This is available in Rietveld refinement software and consists in anisotropic broadening analysis of diffraction peaks. Crystallite size doesn't significantly change with the phase transformation contrary to microstrain that is multiplied, on average, by five. Furthermore, internal normal and shear microstress are multiplied, respectively, by 2 and 13 when {alpha}'-phase appears. Last, dislocation densities, calculated from crystallite size and microstrain, are compared to TEM results available in the literature.

High-pressure phase equilibrium data for systems with carbon dioxide, {alpha}-humulene and trans-caryophyllene

Energy Technology Data Exchange (ETDEWEB)

Michielin, Eliane M.Z.; Rosso, Sibele R [EQA/UFSC, Chemical and Food Engineering Department, Federal University of Santa Catarina, C.P. 476, CEP 88040-900, Florianopolis, SC (Brazil); Franceschi, Elton; Borges, Gustavo R; Corazza, Marcos L; Oliveira, J Vladimir [Department of Food Engineering, URI - Campus de Erechim, Av. Sete de Setembro, 1621, Erechim, RS, 99700-000 (Brazil); Ferreira, Sandra R.S. [EQA/UFSC, Chemical and Food Engineering Department, Federal University of Santa Catarina, C.P. 476, CEP 88040-900, Florianopolis, SC (Brazil)], E-mail: sandra@enq.ufsc.br

2009-01-15

The aim of this work is to report phase equilibrium data for the binary systems (CO{sub 2} + {alpha}-humulene) and (CO{sub 2} + trans-caryophyllene), and for the ternary system (CO{sub 2} + {alpha}-humulene + trans-caryophyllene). Results from literature show that {alpha}-humulene and trans-caryophyllene are the main compounds responsible for the anti-inflammatory and anti-allergic characteristics attributed to the medicinal plant Cordia verbenacea D.C., hence giving importance to the phase behaviour investigation performed in this work. Phase equilibrium experiments were performed in a high-pressure, variable-volume view cell over the temperature range of T = (303 to 343) K and pressures up to 20 MPa. (Liquid + liquid) and (vapour + liquid + liquid) equilibrium were observed at T = 303 K, while (vapour + liquid) phase transitions were verified to occur from T = (313 to 343) K, for all systems studied. Thermodynamic modelling was performed using the Peng-Robinson equation of state and the classical quadratic mixing rules, with a satisfactory agreement between experimental and calculated values.

Effect of mode of rolling on development of texture and microstructure in two-phase ({alpha} + {beta}) brass

Energy Technology Data Exchange (ETDEWEB)

Garg, Rohini; Ranganathan, S. [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India); Suwas, Satyam, E-mail: satyamsuwas@met.iisc.ernet.in [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India)

2010-07-15

The evolution of microstructure and texture during deformation of two-phase ({alpha} + {beta}) brass was studied for different initial microstructure and texture. The deformation processing involved unidirectional and multi-step cross-rolling. The bulk textures were determined by measuring the pole figures and calculating the orientation distribution function ODF for both {alpha} (fcc) and {beta} (bcc) phases, while the microstructure and other microstructural parameters were measured through optical microscopy and scanning electron microscopy with electron back scatter diffraction (SEM-EBSD). Results indicate that textures developed after unidirectional rolling and multi-step cross-rolling are significantly different. The variation in initial texture had a pronounced effect on the development of texture in the {alpha} phase during subsequent deformation.

Zirconium metal-water oxidation kinetics. III. Oxygen diffusion in oxide and alpha Zircaloy phases

International Nuclear Information System (INIS)

Pawel, R.E.

1976-10-01

The reaction of Zircaloy in steam at elevated temperature involves the growth of discrete layers of oxide and oxygen-rich alpha Zircaloy from the parent beta phase. The multiphase, moving boundary diffusion problem involved is encountered in a number of important reaction schemes in addition to that of Zircaloy-oxygen and can be completely (albeitly ideally) characterized through an appropriate model in terms of oxygen diffusion coefficients and equilibrium concentrations for the various phases. Conversely, kinetic data for phase growth and total oxygen consumption rates can be used to compute diffusion coefficients. Equations are developed that express the oxygen diffusion coefficients in the oxide and alpha phases in terms of the reaction rate constants and equilibrium solubility values. These equations were applied to recent experimental kinetic data on the steam oxidation of Zircaloy-4 to determine the effective oxygen diffusion coefficients in these phases over the temperature range 1000--1500 0 C

Alpha-particle diagnostics for the D-T phase

Energy Technology Data Exchange (ETDEWEB)

Conroy, S.W.; Bergsaker, H.; Coad, J.P.; Jarvis, O.N.; Marcus, F.B.; Sadler, G.; Belle, P. van (Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking); McCracken, G.M.; Pitts, R.A. (AEA Fusion, Culham (United Kingdom)); Zhu, J. (Sussex Univ., Brighton (United Kingdom))

1991-01-01

Diagnostics to examine the lost [alpha] particle flux at JET during the D-T phase are under development. A passive [sup 3]He collector probe has been tested during [sup 3]He NBI and RF heated discharges. [sup 3]He ions with energies of at least 100 keV have been detected; their source is probably due to the metastable component of the [sup 3]He NBI. A code has been developed to model the charged particle fluxes at the wall. (author) 5 refs., 4 figs.

Oxidation kinetics of zircaloy-4 in the temperature range correspondent to alpha phase

International Nuclear Information System (INIS)

Medeiros, L.F.

1975-12-01

Oxidation kinetics of Zry-4 in the alpha phase is isothermally studied in the temperature range from 600 0 C to 800 0 C, by continuous and discontinuous gravimetric methods. The total mass gain during the oxidation takes place by two distinct ways: oxide formation and solid solution formation. The first one has been studied by microscopy: the latter by microhardness. The oxygen diffusion coefficients in the zirconium are experimentally determined by microhardness measurements and are compared with those obtained by the oxide layer thickness and by oxygen mass in the oxide. The oxygen diffusion coefficients in the oxide are obtained too by oxide layer thickness and by oxygen diffusivities in the alpha phase and compared with literature. (author)

Human alpha2-macroglobulin is composed of multiple domains, as predicted by homology with complement component C3.

Science.gov (United States)

Doan, Ninh; Gettins, Peter G W

2007-10-01

Human alpha2M (alpha2-macroglobulin) and the complement components C3 and C4 are thiol ester-containing proteins that evolved from the same ancestral gene. The recent structure determination of human C3 has allowed a detailed prediction of the location of domains within human alpha2M to be made. We describe here the expression and characterization of three alpha(2)M domains predicted to be involved in the stabilization of the thiol ester in native alpha2M and in its activation upon bait region proteolysis. The three newly expressed domains are MG2 (macroglobulin domain 2), TED (thiol ester-containing domain) and CUB (complement protein subcomponents C1r/C1s, urchin embryonic growth factor and bone morphogenetic protein 1) domain. Together with the previously characterized RBD (receptor-binding domain), they represent approx. 42% of the alpha2M polypeptide. Their expression as folded domains strongly supports the predicted domain organization of alpha2M. An X-ray crystal structure of MG2 shows it to have a fibronectin type-3 fold analogous to MG1-MG8 of C3. TED is, as predicted, an alpha-helical domain. CUB is a spliced domain composed of two stretches of polypeptide that flank TED in the primary structure. In intact C3 TED interacts with RBD, where it is in direct contact with the thiol ester, and with MG2 and CUB on opposite, flanking sides. In contrast, these alpha2M domains, as isolated species, show negligible interaction with one another, suggesting that the native conformation of alpha2M, and the consequent thiol ester-stabilizing domain-domain interactions, result from additional restraints imposed by the physical linkage of these domains or by additional domains in the protein.

Critical indices for reversible gamma-alpha phase transformation in metallic cerium

Science.gov (United States)

Soldatova, E. D.; Tkachenko, T. B.

1980-08-01

Critical indices for cerium have been determined within the framework of the pseudobinary solution theory along the phase equilibrium curve, the critical isotherm, and the critical isobar. The results obtained verify the validity of relationships proposed by Rushbrook (1963), Griffiths (1965), and Coopersmith (1968). It is concluded that reversible gamma-alpha transformation in metallic cerium is a critical-type transformation, and cerium has a critical point on the phase diagram similar to the critical point of the liquid-vapor system.

Variant Selection during Alpha Precipitation in Titanium Alloys: A Simulation Study

Science.gov (United States)

Shi, Rongpei

Variant selection of alpha phase during its precipitation from beta matrix plays a key role in determining transformation texture and final mechanical properties of alpha/beta and beta titanium alloys. In this study we develop a three-dimensional quantitative phase field model (PFM) to predict variant selection and microstructure evolution during beta to alpha transformation in polycrystalline Ti-6Al-4V under the influence of different processing variables. The model links its inputs directly to thermodynamic and mobility databases, and incorporates crystallography of BCC to HCP transformation, elastic anisotropy, defects within semi-coherent alpha/beta interfaces and elastic inhomogeneities among different beta grains. In particular, microstructure and transformation texture evolution are treated simultaneously via orientation distribution function (ODF) modeling of alpha/beta two-phase microstructure in beta polycrystalline obtained by PFM. It is found that, for a given undercooling, the development of transformation texture of the alpha phase due to variant selection during precipitation depends on both externally applied stress or strain, initial texture state of parent beta sample and internal stress generated by the precipitation reaction itself. Moreover, the growth of pre-existing widmanstatten alpha precipitates is accompanied by selective nucleation and growth of secondary alpha plates of preferred variants. We further develop a crystallographic model based on the ideal Burgers orientation relationship (BOR) between GBalpha and one of the two adjacent beta grains to investigate how a prior beta grain boundary contributes to variant selection of grain boundary allotriomorph (GBalpha). The model is able to predict all possible special beta grain boundaries where GBalpha is able to maintain BOR with two neighboring grain. In particular, the model has been used to evaluate the validity of all current empirical variant selection rules to obtain more insight of

SPS-ALPHA: The First Practical Solar Power Satellite via Arbitrarily Large PHased Array

Data.gov (United States)

National Aeronautics and Space Administration — SPS-ALPHA (Solar Power Satellite via Arbitrarily Large Phased Array) is a novel, bio-mimetic approach to the challenge of space solar power. If successful, this...

DT results of TFTR's alpha collector

International Nuclear Information System (INIS)

Herrmann, H.W.; Zweben, S.J.; Darrow, D.S.; Timberlake, J.R.; Macaulay-Newcombe, R.G.

1996-01-01

An escaping alpha collector probe has been developed for TFTR's DT phase to complement the results of the lost alpha scintillator detectors which have been operating on TFTR since 1988. Measurements of the energy distribution of escaping alphas have been made by measuring the range of alphas implanted into nickel foils located within the alpha collector. Exposed samples have been analyzed for 4 DT plasma discharges at plasma currents of 1.0 and 1.8 MA. The results at 1.0 MA are in good agreement with predictions for first orbit alpha loss at 3.5 MeV. The 1.8 MA results, however, indicate a large anomalous loss of partially thermalized alphas at an energy ∼30% below the birth energy and at a total fluence nearly an order of magnitude above expected first orbit loss. This anomalous loss is not observed with the lost alpha scintillator detectors in DT plasmas but does resemble the anomalous delayed loss seen in DD plasmas. Several potential explanations for this loss process are examined. None of the candidate explanations proposed thus far are fully consistent with the anomalous loss observations

Gapless Spin Excitations in the Field-Induced Quantum Spin Liquid Phase of alpha-RuCl3

OpenAIRE

Zheng, Jiacheng; Ran, Kejing; Li, Tianrun; Wang, Jinghui; Wang, Pengshuai; Liu, Bin; Liu, Zhengxin; Normand, B.; Wen, Jinsheng; Yu, Weiqiang

2017-01-01

$\\alpha$-RuCl$_3$ is a leading candidate material for theobservation of physics related to the Kitaev quantum spin liquid (QSL). By combined susceptibility, specific-heat, and nuclear-magnetic-resonance measurements, we demonstrate that $\\alpha$-RuCl$_3$ undergoes a quantum phase transition to a QSL in a magnetic field of 7.5 T applied in the $ab$ plane. We show further that this high-field QSL phase has gapless spin excitations over a field range up to 16 T. This highly unconventional result...

A rational approach to predict and modulate stereolability of chiral alpha substituted ketones.

Science.gov (United States)

Cirilli, Roberto; Costi, Roberta; Di Santo, Roberto; Gasparrini, Francesco; La Torre, Francesco; Pierini, Marco; Siani, Gabriella

2009-01-01

An effective strategy to assess and modulate the stereolability of chiral alpha substituted ketones (C alpha SKs) is presented. The tendency of C alpha SKs to retain or change their configuration in water is analyzed as a function of thermodynamic proton-release attitude of alpha asymmetric atoms inside the structures by linear Brønsted correlations. A molecular modeling procedure was developed to analyze and suggest chemical modifications of C alpha SKs in view to obtain the desired grade of stereochemical stability. The approach was employed to predict the tendency to enantiomerize in water of two ketones (1 and 2) endowed with inhibitory activity against monoamine oxidases (MAOs) and the results were confirmed by experimental kinetics measurements performed in organic medium. As a demonstration of practical potentialities of the approach, four new structures, conceived as simple chemical modifications of 1 and 2, were designed to improve/reduce the stereostability grade of the starting anti-MAO ketones. The possibility to extend easily the procedure to other classes of C-H acids appears of interest.

Alpha-Band Rhythms in Visual Task Performance: Phase-Locking by Rhythmic Sensory Stimulation

Science.gov (United States)

de Graaf, Tom A.; Gross, Joachim; Paterson, Gavin; Rusch, Tessa; Sack, Alexander T.; Thut, Gregor

2013-01-01

Oscillations are an important aspect of neuronal activity. Interestingly, oscillatory patterns are also observed in behaviour, such as in visual performance measures after the presentation of a brief sensory event in the visual or another modality. These oscillations in visual performance cycle at the typical frequencies of brain rhythms, suggesting that perception may be closely linked to brain oscillations. We here investigated this link for a prominent rhythm of the visual system (the alpha-rhythm, 8–12 Hz) by applying rhythmic visual stimulation at alpha-frequency (10.6 Hz), known to lead to a resonance response in visual areas, and testing its effects on subsequent visual target discrimination. Our data show that rhythmic visual stimulation at 10.6 Hz: 1) has specific behavioral consequences, relative to stimulation at control frequencies (3.9 Hz, 7.1 Hz, 14.2 Hz), and 2) leads to alpha-band oscillations in visual performance measures, that 3) correlate in precise frequency across individuals with resting alpha-rhythms recorded over parieto-occipital areas. The most parsimonious explanation for these three findings is entrainment (phase-locking) of ongoing perceptually relevant alpha-band brain oscillations by rhythmic sensory events. These findings are in line with occipital alpha-oscillations underlying periodicity in visual performance, and suggest that rhythmic stimulation at frequencies of intrinsic brain-rhythms can be used to reveal influences of these rhythms on task performance to study their functional roles. PMID:23555873

Multiphase, multicomponent phase behavior prediction

Science.gov (United States)

Dadmohammadi, Younas

Accurate prediction of phase behavior of fluid mixtures in the chemical industry is essential for designing and operating a multitude of processes. Reliable generalized predictions of phase equilibrium properties, such as pressure, temperature, and phase compositions offer an attractive alternative to costly and time consuming experimental measurements. The main purpose of this work was to assess the efficacy of recently generalized activity coefficient models based on binary experimental data to (a) predict binary and ternary vapor-liquid equilibrium systems, and (b) characterize liquid-liquid equilibrium systems. These studies were completed using a diverse binary VLE database consisting of 916 binary and 86 ternary systems involving 140 compounds belonging to 31 chemical classes. Specifically the following tasks were undertaken: First, a comprehensive assessment of the two common approaches (gamma-phi (gamma-ϕ) and phi-phi (ϕ-ϕ)) used for determining the phase behavior of vapor-liquid equilibrium systems is presented. Both the representation and predictive capabilities of these two approaches were examined, as delineated form internal and external consistency tests of 916 binary systems. For the purpose, the universal quasi-chemical (UNIQUAC) model and the Peng-Robinson (PR) equation of state (EOS) were used in this assessment. Second, the efficacy of recently developed generalized UNIQUAC and the nonrandom two-liquid (NRTL) for predicting multicomponent VLE systems were investigated. Third, the abilities of recently modified NRTL model (mNRTL2 and mNRTL1) to characterize liquid-liquid equilibria (LLE) phase conditions and attributes, including phase stability, miscibility, and consolute point coordinates, were assessed. The results of this work indicate that the ϕ-ϕ approach represents the binary VLE systems considered within three times the error of the gamma-ϕ approach. A similar trend was observed for the for the generalized model predictions using

Individual Alpha Peak Frequency Predicts 10 Hz Flicker Effects on Selective Attention.

Science.gov (United States)

Gulbinaite, Rasa; van Viegen, Tara; Wieling, Martijn; Cohen, Michael X; VanRullen, Rufin

2017-10-18

Rhythmic visual stimulation ("flicker") is primarily used to "tag" processing of low-level visual and high-level cognitive phenomena. However, preliminary evidence suggests that flicker may also entrain endogenous brain oscillations, thereby modulating cognitive processes supported by those brain rhythms. Here we tested the interaction between 10 Hz flicker and endogenous alpha-band (∼10 Hz) oscillations during a selective visuospatial attention task. We recorded EEG from human participants (both genders) while they performed a modified Eriksen flanker task in which distractors and targets flickered within (10 Hz) or outside (7.5 or 15 Hz) the alpha band. By using a combination of EEG source separation, time-frequency, and single-trial linear mixed-effects modeling, we demonstrate that 10 Hz flicker interfered with stimulus processing more on incongruent than congruent trials (high vs low selective attention demands). Crucially, the effect of 10 Hz flicker on task performance was predicted by the distance between 10 Hz and individual alpha peak frequency (estimated during the task). Finally, the flicker effect on task performance was more strongly predicted by EEG flicker responses during stimulus processing than during preparation for the upcoming stimulus, suggesting that 10 Hz flicker interfered more with reactive than proactive selective attention. These findings are consistent with our hypothesis that visual flicker entrained endogenous alpha-band networks, which in turn impaired task performance. Our findings also provide novel evidence for frequency-dependent exogenous modulation of cognition that is determined by the correspondence between the exogenous flicker frequency and the endogenous brain rhythms. SIGNIFICANCE STATEMENT Here we provide novel evidence that the interaction between exogenous rhythmic visual stimulation and endogenous brain rhythms can have frequency-specific behavioral effects. We show that alpha-band (10 Hz) flicker impairs stimulus

Prediction of Chevrel superconducting phases

International Nuclear Information System (INIS)

Savitskij, E.M.; Kiseleva, N.N.

1978-01-01

Made is an attempt of predicting the possibility of formation of compounds of Mo 3 Se 4 type structure having critical temperatures of transition into superconducting state more than 4.2 K. Cybernetic method of teaching an electronic computer to form notions is used for prediction. Prediction system constructs logic dependence of forming Chevrel superconducting phase of the Asub(x)Bsub(6)Ssub(8) composition (A being an element of the periodic system; B=Cr, Mo, W, Re) and Asub(x)Bsub(6)Ssub(8) compounds having a critical temperature of more than 4.2 K on the properties of A and B elements. A conclusion is made that W, Re, Cr do not form Chevrel phases of the Asub(x)Bsub(6)Ssub(8) composition as B component. Be, Hg, Ra, B, Ac are the reserve for obtaining Asub(x)Mosub(6)Ssub(8) phases. Agsub(x)Mosub(6)Ssub(8) compound may have a high critical temperature. The ways of a critical temperature increase for Chevrel phases are connected with the search of optimal technological conditions for already known superconducting compounds and also with introduction of impurities fixing a distance between sulfur cubes

Ion current prediction model considering columnar recombination in alpha radioactivity measurement using ionized air transportation

International Nuclear Information System (INIS)

Naito, Susumu; Hirata, Yosuke; Izumi, Mikio; Sano, Akira; Miyamoto, Yasuaki; Aoyama, Yoshio; Yamaguchi, Hiromi

2007-01-01

We present a reinforced ion current prediction model in alpha radioactivity measurement using ionized air transportation. Although our previous model explained the qualitative trend of the measured ion current values, the absolute values of the theoretical curves were about two times as large as the measured values. In order to accurately predict the measured values, we reinforced our model by considering columnar recombination and turbulent diffusion, which affects columnar recombination. Our new model explained the considerable ion loss in the early stage of ion diffusion and narrowed the gap between the theoretical and measured values. The model also predicted suppression of ion loss due to columnar recombination by spraying a high-speed air flow near a contaminated surface. This suppression was experimentally investigated and confirmed. In conclusion, we quantitatively clarified the theoretical relation between alpha radioactivity and ion current in laminar flow and turbulent pipe flow. (author)

Gamma activity coupled to alpha phase as a mechanism for top-down controlled gating

NARCIS (Netherlands)

Bonnefond, M.; Jensen, O.

2015-01-01

Coupling between neural oscillations in different frequency bands has been proposed to coordinate neural processing. In particular, gamma power coupled to alpha phase is proposed to reflect gating of information in the visual system but the existence of such a mechanism remains untested. Here, we

Antecedent occipital alpha band activity predicts the impact of oculomotor events in perceptual switching

Directory of Open Access Journals (Sweden)

Hironori eNakatani

2013-05-01

Full Text Available Oculomotor events such as blinks and saccades transiently interrupt the visual input and, even though this mostly goes undetected, these brief interruptions could still influence the percept. In particular, both blinking and saccades facilitate switching in ambiguous figures such as the Necker cube. To investigate the neural state antecedent to these oculomotor events during the perception of an ambiguous figure, we measured the human scalp electroencephalogram (EEG. When blinking led to perceptual switching, antecedent occipital alpha band activity exhibited a transient increase in amplitude. When a saccade led to switching, a series of transient increases and decreases in amplitude was observed in the antecedent occipital alpha band activity. Our results suggest that the state of occipital alpha band activity predicts the impact of oculomotor events on the percept.

Expression of alpha-amylase in Bacillus licheniformis.

OpenAIRE

Rothstein, D M; Devlin, P E; Cate, R L

1986-01-01

In Bacillus licheniformis, alpha-amylase production varied more than 100-fold depending on the presence or absence of a catabolite-repressing carbon source in the growth medium. alpha-Amylase was produced during the growth phase and not at the onset of the stationary phase. Induction of alpha-amylase correlated with synthesis of mRNA initiating at the promoter of the alpha-amylase gene.

Tumor necrosis factor-alpha binding capacity and anti-infliximab antibodies measured by fluid-phase radioimmunoassays as predictors of clinical efficacy of infliximab in Crohn's disease

DEFF Research Database (Denmark)

Ainsworth, Mark A; Bendtzen, Klaus; Brynskov, Jørn

2007-01-01

To investigate if the combined assessment of anti-infliximab antibodies (Ab) and the degree of TNF-alpha binding capacity (TNF-alpha-BC) afforded by infliximab may predict the response to infliximab treatment in patients with Crohn's disease (CD).......To investigate if the combined assessment of anti-infliximab antibodies (Ab) and the degree of TNF-alpha binding capacity (TNF-alpha-BC) afforded by infliximab may predict the response to infliximab treatment in patients with Crohn's disease (CD)....

Plant diversity predicts beta but not alpha diversity of soil microbes across grasslands worldwide

Science.gov (United States)

Prober, Suzanne M.; Leff, Jonathan W.; Bates, Scott T.; Borer, Elizabeth T.; Firn, Jennifer; Harpole, W. Stanley; Lind, Eric M.; Seabloom, Eric W.; Adler, Peter B.; Bakker, Jonathan D.; Cleland, Elsa E.; DeCrappeo, Nicole; DeLorenze, Elizabeth; Hagenah, Nicole; Hautier, Yann; Hofmockel, Kirsten S.; Kirkman, Kevin P.; Knops, Johannes M. H.; La Pierre, Kimberly J.; MacDougall, Andrew S.; McCulley, Rebecca L.; Mitchell, Charles E.; Risch, Anita C.; Schuetz, Martin; Stevens, Carly J.; Williams, Ryan J.; Fierer, Noah

2015-01-01

Aboveground–belowground interactions exert critical controls on the composition and function of terrestrial ecosystems, yet the fundamental relationships between plant diversity and soil microbial diversity remain elusive. Theory predicts predominantly positive associations but tests within single sites have shown variable relationships, and associations between plant and microbial diversity across broad spatial scales remain largely unexplored. We compared the diversity of plant, bacterial, archaeal and fungal communities in one hundred and forty-five 1 m2 plots across 25 temperate grassland sites from four continents. Across sites, the plant alpha diversity patterns were poorly related to those observed for any soil microbial group. However, plant beta diversity (compositional dissimilarity between sites) was significantly correlated with the beta diversity of bacterial and fungal communities, even after controlling for environmental factors. Thus, across a global range of temperate grasslands, plant diversity can predict patterns in the composition of soil microbial communities, but not patterns in alpha diversity.

Solubilization and precipitation of {omega} and {alpha} phases in Ti-30 Nb and Ti-35 Nb alloys; Solubilizacao e precipitacao de fases {omega} e {alpha} nas ligas Ti-30Nb e Ti-35Nb

Energy Technology Data Exchange (ETDEWEB)

Hayama, A.O.F.; Lopes, J.F.S.C.; Caram, R., E-mail: alexandrah@fem.unicamp.b [Universidade Estadual de Campinas (DEMa/FEM/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Dept. de Engenharia de Materiais

2010-07-01

This work presents the main results of the characterization of Ti-30Nb and Ti-35Nb alloys (wt%) submitted to the solutioning heat treatment following by aging. Samples were obtained by electric arc melting, followed by solution heat treatment at 1000 deg C during 8 hours and cooling in water, the microstructure obtained is formed by {beta} and {alpha} phases. Samples were aged at 260 and 400 deg C during periods of time varying from 1 to 240 min. Characterization was performed using light optical microscopy, X-ray diffraction, Young's modulus measurements by acoustic emission and Vickers hardness. The results show the presence of {beta} and {alpha}{sup '}' phases in samples of the Ti-30Nb alloy aged at 260 deg C. In samples aged at 400 deg C, precipitation of {omega} and {alpha}{sup '}' phases took place, and due to this fact, an increase in Young's modulus and in hardness occurred. (author)

Spontaneous Alpha Power Lateralization Predicts Detection Performance in an Un-Cued Signal Detection Task.

Directory of Open Access Journals (Sweden)

Gonzalo Boncompte

Full Text Available Focusing one's attention by external guiding stimuli towards a specific area of the visual field produces systematical neural signatures. One of the most robust is the change in topological distribution of oscillatory alpha band activity across parieto-occipital cortices. In particular, decreases in alpha activity over contralateral and/or increases over ipsilateral scalp sites, respect to the side of the visual field where attention was focused. This evidence comes mainly from experiments where an explicit cue informs subjects where to focus their attention, thus facilitating detection of an upcoming target stimulus. However, recent theoretical models of attention have highlighted a stochastic or non-deterministic component related to visuospatial attentional allocation. In an attempt to evidence this component, here we analyzed alpha activity in a signal detection paradigm in the lack of informative cues; in the absence of preceding information about the location (and time of appearance of target stimuli. We believe that the unpredictability of this situation could be beneficial for unveiling this component. Interestingly, although total alpha power did not differ between Seen and Unseen conditions, we found a significant lateralization of alpha activity over parieto-occipital electrodes, which predicted behavioral performance. This effect had a smaller magnitude compared to paradigms in which attention is externally guided (cued. However we believe that further characterization of this spontaneous component of attention is of great importance in the study of visuospatial attentional dynamics. These results support the presence of a spontaneous component of visuospatial attentional allocation and they advance pre-stimulus alpha-band lateralization as one of its neural signatures.

Fusion performances and alpha heating in future JET D-T plasmas

Energy Technology Data Exchange (ETDEWEB)

Balet, B; Cordey, J G; Gibson, A; Lomas, P; Stubberfield, P M; Thomas, P [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

1994-07-01

The new pump divertor installed at JET should allow high performance pulses of a few seconds duration by both preventing the impurity influx and controlling the density evolution. The TRANSP code has been used in a predictive mode to assess the possible fusion performance of such plasmas fuelled with a 50:50 mixture of D and T, and the effect of alpha particles heating on Te and Ti. Several cases are considered: 50:50 D-T mix; 50:50 D-T mix, no C bloom; 50:50 D-T mix, VH phase, density control; 50:50 D-T mix, VH phase, density control, 6 Ma. The predictions show that if the the bloom and MHD instabilities can be controlled at higher plasma currents using a higher toroidal field to keep a reasonable beta value, then a higher fusion performance steady state plasma with Q{sub DT} superior to 2.5 should be possible. The alpha heating power of 4.9 MW would lead to a 74% increase in Te. 4 refs., 4 figs., 1 tab.

Electronic, optical and transport properties of {alpha}-, {beta}- and {gamma}-phases of spinel indium sulphide: An ab initio study

Energy Technology Data Exchange (ETDEWEB)

Sharma, Yamini, E-mail: sharma.yamini62@gmail.com [Department of Physics, Feroze Gandhi College, Rae Bareli 229001, U.P. (India); Srivastava, Pankaj [Department of Physics, Feroze Gandhi College, Rae Bareli 229001, U.P. (India)

2012-08-15

Spinel indium sulphide exists in three phases. The tetragonal {beta}-phase transforms to the cubic {alpha}-phase at 420 Degree-Sign C which further transforms to the trigonal {gamma}-phase at 754 Degree-Sign C. Due to wide energy bandgap, the phases of indium sulphide have possibilities of applications in photo-electrochemical solar cell devices as a replacement of toxic CdS. The electronic, optical and transport properties of the three phases have therefore been investigated using full potential linear augmented plane wave (FP-LAPW) + local orbitals (lo) scheme, in the framework of density functional theory (DFT) with generalized gradient approximation (GGA) for the purpose of exchange-correlation energy functional. We present the structure, energy bands and density of states (DOS) for {alpha}-, {beta}- and {gamma}-phases. The partial density of states (PDOS) of {beta}-In{sub 2}S{sub 3} is in good agreement with experiment and earlier ab initio calculations. To obtain the fundamental characteristics of these phases we have analysed their linear optical properties such as the dynamic dielectric function in the energy range of 0-15 eV. From the dynamic dielectric function it is seen that there is no directional anisotropy for {alpha}-phase since the longitudinal and transverse components are almost identical, however the {beta} and {gamma}-phases show birefringence. The optical absorption profiles clearly indicate that {beta}-phase has possibility of greater multiple direct and indirect interband transitions in the visible regions compared to the other phases. To study the existence of interesting thermoelectric properties, transport properties like electrical and thermal conductivities, Seebeck and Hall coefficients etc. are also calculated. Good agreements are found with the available experimental results. -- Highlights: Black-Right-Pointing-Pointer The electronic properties of phases of In{sub 2}S{sub 3} have been investigated. Black-Right-Pointing-Pointer The

Knowledge-based artificial neural network model to predict the properties of alpha+ beta titanium alloys

Energy Technology Data Exchange (ETDEWEB)

Banu, P. S. Noori; Rani, S. Devaki [Dept. of Metallurgical Engineering, Jawaharlal Nehru Technological University, HyderabadI (India)

2016-08-15

In view of emerging applications of alpha+beta titanium alloys in aerospace and defense, we have aimed to develop a Back propagation neural network (BPNN) model capable of predicting the properties of these alloys as functions of alloy composition and/or thermomechanical processing parameters. The optimized BPNN model architecture was based on the sigmoid transfer function and has one hidden layer with ten nodes. The BPNN model showed excellent predictability of five properties: Tensile strength (r: 0.96), yield strength (r: 0.93), beta transus (r: 0.96), specific heat capacity (r: 1.00) and density (r: 0.99). The developed BPNN model was in agreement with the experimental data in demonstrating the individual effects of alloying elements in modulating the above properties. This model can serve as the platform for the design and development of new alpha+beta titanium alloys in order to attain desired strength, density and specific heat capacity.

Anti-IL-1alpha autoantibodies in early rheumatoid arthritis

DEFF Research Database (Denmark)

Forslind, K; Svensson, Birte; Svenson, M

2001-01-01

To investigate the potential predictive value of autoantibodies against IL1-alpha (anti-IL-1alpha) in patients with early rheumatoid arthritis (RA).......To investigate the potential predictive value of autoantibodies against IL1-alpha (anti-IL-1alpha) in patients with early rheumatoid arthritis (RA)....

Melting, casting, and alpha-phase extrusion of the uranium-2.4 weight percent niobium alloy

International Nuclear Information System (INIS)

Anderson, R.C.; Beck, D.E.; Kollie, T.G.; Zorinsky, E.J.; Jones, J.M.

1981-10-01

The experimental details of the melting, casting, homogenization, and alpha-phase extrusion process used to fabricate the uranium-2.4 wt % niobium alloy into 46-mm-diameter rods is described. Extrusion defects that were detected by an ultrasonic technique were eliminated by proper choice of extrusion parameters; namely, reduction ratio, ram speed, die angle, and billet preheat temperature

The rat acute-phase protein {alpha}{sub 2}-macroglobulin plays a central role in amifostine-mediated radioprotection

Energy Technology Data Exchange (ETDEWEB)

Mirjana, Mihailovic; Goran, Poznanovic; Nevena, Grdovic; Melita, Vidakovic; Svetlana, Dinic; Ilijana, Grigorov; Desanka, Bogojevic, E-mail: mista@ibiss.bg.ac.r [Department of Molecular Biology, Institute for Biological Research ' Sinisa Stankovic' , University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade (Serbia)

2010-09-15

Previously we reported that elevated circulating concentrations of the acute-phase (AP) protein {alpha}{sub 2}-macroglobulin ({alpha}{sub 2}M), either as typically occurring in pregnant female rats or after administration to male rats, provides radioprotection, displayed as 100% survival of experimental animals exposed to total-body irradiation with 6.7 Gy (LD{sub 50/30}) x-rays, that is as effective as that afforded by the synthetic radioprotector amifostine. The finding that amifostine administration induces a 45-fold increase in {alpha}{sub 2}M in the circulation led us to hypothesise that {alpha}{sub 2}M assumes an essential role in both natural and amifostine-mediated radioprotection in the rat. In the present work we examined the activation of cytoprotective mechanisms in rat hepatocytes after the exogenous administration of {alpha}{sub 2}M and amifostine. Our results showed that the IL6/JAK/STAT3 hepatoprotective signal pathway, described in a variety of liver-injury models, upregulated the {alpha}{sub 2}M gene in amifostine-pretreated animals. In both {alpha}{sub 2}M- and amifostine-pretreated rats we observed the activation of the Akt signalling pathways that mediate cellular survival. At the cellular level this was reflected as a significant reduction of irradiation-induced DNA damage that allowed for the rapid and complete restoration of liver mass and ultimately at the level of the whole organism the complete restoration of body weight. We conclude that the selective upregulation of {alpha}{sub 2}M plays a central role in amifostine-provided radioprotection.

Bayesian Statistics at Work: the Troublesome Extraction of the CKM Phase {alpha}

Energy Technology Data Exchange (ETDEWEB)

Charles, J. [CPT, Luminy Case 907, F-13288 Marseille Cedex 9 (France); Hoecker, A. [CERN, CH-1211 Geneva 23 (Switzerland); Lacker, H. [TU Dresden, IKTP, D-01062 Dresden (Germany); Le Diberder, F.R. [LAL, CNRS/IN2P3, Universite Paris-Sud 11, Bat. 200, BP 34, F-91898 Orsay Cedex (France); T' Jampens, S. [LAPP, CNRS/IN2P3, Universite de Savoie, 9 Chemin de Bellevue, BP 110, F-74941 Annecy-le-Vieux Cedex (France)

2007-04-15

In Bayesian statistics, one's prior beliefs about underlying model parameters are revised with the information content of observed data from which, using Bayes' rule, a posterior belief is obtained. A non-trivial example taken from the isospin analysis of B {yields} PP (P = {pi} or {rho}) decays in heavy-flavor physics is chosen to illustrate the effect of the naive 'objective' choice of flat priors in a multi- dimensional parameter space in presence of mirror solutions. It is demonstrated that the posterior distribution for the parameter of interest, the phase {alpha}, strongly depends on the choice of the parameterization in which the priors are uniform, and on the validity range in which the (un-normalizable) priors are truncated. We prove that the most probable values found by the Bayesian treatment do not coincide with the explicit analytical solutions, in contrast to the frequentist approach. It is also shown in the appendix that the {alpha} {yields} 0 limit cannot be consistently treated in the Bayesian paradigm, because the latter violates the physical symmetries of the problem. (authors)

Time resolved reflectivity measurements of the amorphous-to-gamma and gamma-to-alpha phase transitions in ion-implanted Al2O3

International Nuclear Information System (INIS)

McCallum, J.C.; Simpson, T.W.; Mitchell, I.V.

1994-01-01

Time resolved optical reflectivity (TRR) has been used to measure the growth kinetics associated with the amorphous-to-gamma and gamma-to-alpha phase transitions in ion-beam amorphised c-axis oriented α-Al 2 O 3 . The optical reflectivity technique allows the recrystallisation behaviour to be monitored dynamically during regrowth so that the growth kinetics associated with the two phase transitions can be measured simply and accurately from a relatively small number of samples. The amorphous-to-gamma and gamma-to-alpha phase transitions were studied over the temperature ranges of 670-770 C and 900-1070 C, respectively. The growth kinetics obtained for the two transitions are compared to previous work. ((orig.))

Alpha particles spectrometer with photodiode PIN

International Nuclear Information System (INIS)

Chacon R, A.; Hernandez V, R.; Hernandez D, V. M.; Vega C, H. R.; Ramirez G, J.

2009-10-01

The radiation propagates in form of electromagnetic waves or corpuscular radiation; if the radiation energy causes ionization in environment that crosses it is considered ionizing radiation. To detect radiation several detectors types are used, if the radiation are alpha particles are used detectors proportional type or trace elements. In this work the design results, construction and tests of an alpha particles spectrometer are presented, which was designed starting from a photodiode PIN type. The system design was simulated with a code for electronic circuits. With results of simulation phase was constructed the electronic phase that is coupled to a multichannel analyzer. The resulting electronic is evaluated analyzing the electronic circuit performance before an alphas triple source and alpha radiation that produce two smoke detectors of domestic use. On the tests phase we find that the system allows obtain, in a multichannel, the pulses height spectrum, with which we calibrate the system. (Author)

Prediction of two-phase choked-flow through safety valves

International Nuclear Information System (INIS)

Arnulfo, G; Bertani, C; De Salve, M

2014-01-01

Different models of two-phase choked flow through safety valves are applied in order to evaluate their capabilities of prediction in different thermal-hydraulic conditions. Experimental data available in the literature for two-phase fluid and subcooled liquid upstream the safety valve have been compared with the models predictions. Both flashing flows and non-flashing flows of liquid and incondensable gases have been considered. The present paper shows that for flashing flows good predictions are obtained by using the two-phase valve discharge coefficient defined by Lenzing and multiplying it by the critical flow rate in an ideal nozzle evaluated by either Omega Method or the Homogeneous Non-equilibrium Direct Integration. In case of non-flashing flows of water and air, Leung/Darby formulation of the two-phase valve discharge coefficient together with the Omega Method is more suitable to the prediction of flow rate.

Tonic pain and continuous EEG: prediction of subjective pain perception by alpha-1 power during stimulation and at rest.

Science.gov (United States)

Nir, Rony-Reuven; Sinai, Alon; Moont, Ruth; Harari, Eyal; Yarnitsky, David

2012-03-01

Pain neurophysiology has been chiefly characterized via event-related potentials (ERPs), which are exerted using brief, phase-locked noxious stimuli. Striving for objectively characterizing clinical pain states using more natural, prolonged stimuli, tonic pain has been recently associated with the individual peak frequency of alpha oscillations. This finding encouraged us to explore whether alpha power, reflecting the magnitude of the synchronized activity within this frequency range, will demonstrate a corresponding relationship with subjective perception of tonic pain. Five-minute-long continuous EEG was recorded in 18 healthy volunteers under: (i) resting-state; (ii) innocuous temperature; and (iii) psychophysically-anchored noxious temperature. Numerical pain scores (NPSs) collected during the application of tonic noxious stimuli were tested for correlation with alpha-1 and alpha-2 power. NPSs and alpha power remained stable throughout the recording conditions (Ps⩾0.381). In the noxious condition, alpha-1 power obtained at the bilateral temporal scalp was negatively correlated with NPSs (Ps⩽0.04). Additionally, resting-state alpha-1 power recorded at the bilateral temporal scalp was negatively correlated with NPSs reported during the noxious condition (Ps⩽0.038). Current findings suggest alpha-1 power may serve as a direct, objective and experimentally stable measure of subjective perception of tonic pain. Furthermore, resting-state alpha-1 power might reflect individuals' inherent tonic pain responsiveness. The relevance of alpha-1 power to tonic pain perception may deepen the understanding of the mechanisms underlying the processing of prolonged noxious stimulation. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

SUB-THz AND H{alpha} ACTIVITY DURING THE PREFLARE AND MAIN PHASES OF A GOES CLASS M2 EVENT

Energy Technology Data Exchange (ETDEWEB)

Kaufmann, Pierre; Gimenez de Castro, C. Guillermo; Raulin, Jean-Pierre; Correia, Emilia; Fernandes, Luis Olavo; De Souza, Rodney V. [CRAAM, Escola de Engenharia, Universidade Presbiteriana Mackenzie, Sao Paulo (Brazil); Marcon, Rogerio [IFGW, Universidade Estadual de Campinas (Brazil); White, Stephen M. [AFRL, Space Vehicles Directorate, Albuquerque, NM (United States); Godoy, Rodolfo; Marun, Adolfo; Pereyra, Pablo [Complejo Astronomico El Leoncito, CONICET, San Juan (Argentina)

2011-12-01

Radio and optical observations of the evolution of flare-associated phenomena have shown an initial and rapid burst at 0.4 THz only followed subsequently by a localized chromospheric heating producing an H{alpha} brightening with later heating of the whole active region. A major instability occurred several minutes later producing one impulsive burst at microwaves only, associated with an M2.0 GOES X-ray flare that exhibited the main H{alpha} brightening at the same site as the first flash.The possible association between long-enduring time profiles at soft X-rays, microwaves, H{alpha}, and sub-THz wavelengths is discussed. In the decay phase, the H{alpha} movie shows a disrupting magnetic arch structure ejecting dark, presumably chromospheric, material upward. The time sequence of events suggests genuine interdependent and possibly non-thermal instabilities triggering phenomena, with concurrent active region plasma heating and material ejection.

QCD analyses and determinations of $\\alpha_{s}$ in $e^{+}e^{-}$ annihilation at energies between 35 and 189 GeV

CERN Document Server

Pfeifenschneider, P.; Movilla Fernandez, P.A.; Abbiendi, G.; Ackerstaff, K.; Akesson, P.F.; Alexander, G.; Allison, John; Anderson, K.J.; Arcelli, S.; Asai, S.; Ashby, S.F.; Axen, D.; Azuelos, G.; Bailey, I.; Ball, A.H.; Barberio, E.; Barlow, Roger J.; Batley, J.R.; Baumann, S.; Behnke, T.; Bell, Kenneth Watson; Bella, G.; Bellerive, A.; Bentvelsen, S.; Bethke, S.; Biguzzi, A.; Bloodworth, I.J.; Bock, P.; Bohme, J.; Boeriu, O.; Bonacorsi, D.; Boutemeur, M.; Braibant, S.; Bright-Thomas, P.; Brigliadori, L.; Brown, Robert M.; Burckhart, H.J.; Cammin, J.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Chrisman, D.; Ciocca, C.; Clarke, P.E.L.; Clay, E.; Cohen, I.; Cooke, O.C.; Couchman, J.; Couyoumtzelis, C.; Coxe, R.L.; Cuffiani, M.; Dado, S.; Dallavalle, G.Marco; Dallison, S.; Davis, R.; de Roeck, A.; Dervan, P.; Desch, K.; Dienes, B.; Dixit, M.S.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Estabrooks, P.G.; Etzion, E.; Fabbri, F.; Fanfani, A.; Fanti, M.; Faust, A.A.; Feld, L.; Ferrari, P.; Fiedler, F.; Fierro, M.; Fleck, I.; Frey, A.; Furtjes, A.; Futyan, D.I.; Gagnon, P.; Gary, J.W.; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Gingrich, D.M.; Glenzinski, D.; Goldberg, J.; Gorn, W.; Grandi, C.; Graham, K.; Gross, E.; Grunhaus, J.; Gruwe, M.; Gunther, P.O.; Hajdu, C.; Hanson, G.G.; Hansroul, M.; Hapke, M.; Harder, K.; Harel, A.; Hargrove, C.K.; Harin-Dirac, M.; Hauke, A.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Hensel, C.; Herten, G.; Heuer, R.D.; Hildreth, M.D.; Hill, J.C.; Hobson, P.R.; Hocker, James Andrew; Hoffman, Kara Dion; Homer, R.J.; Honma, A.K.; Horvath, D.; Hossain, K.R.; Howard, R.; Huntemeyer, P.; Igo-Kemenes, P.; Imrie, D.C.; Ishii, K.; Jacob, F.R.; Jawahery, A.; Jeremie, H.; Jimack, M.; Jones, C.R.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karapetian, G.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Kayal, P.I.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kim, D.H.; Klier, A.; Kobayashi, T.; Kobel, M.; Kokott, T.P.; Kolrep, M.; Komamiya, S.; Kowalewski, Robert V.; Kress, T.; Krieger, P.; von Krogh, J.; Kuhl, T.; Kupper, M.; Kyberd, P.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Lawson, I.; Layter, J.G.; Leins, A.; Lellouch, D.; Letts, J.; Levinson, L.; Liebisch, R.; Lillich, J.; List, B.; Littlewood, C.; Lloyd, A.W.; Lloyd, S.L.; Loebinger, F.K.; Long, G.D.; Losty, M.J.; Lu, J.; Ludwig, J.; Macchiolo, A.; Macpherson, A.; Mader, W.; Mannelli, M.; Marcellini, S.; Marchant, T.E.; Martin, A.J.; Martin, J.P.; Martinez, G.; Mashimo, T.; Mattig, Peter; McDonald, W.John; McKenna, J.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Mendez-Lorenzo, P.; Merritt, F.S.; Mes, H.; Meyer, I.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Mohr, W.; Montanari, A.; Mori, T.; Nagai, K.; Nakamura, I.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oakham, F.G.; Odorici, F.; Ogren, H.O.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Patt, J.; Perez-Ochoa, R.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poli, B.; Polok, J.; Przybycien, M.; Quadt, A.; Rembser, C.; Rick, H.; Robins, S.A.; Rodning, N.; Roney, J.M.; Rosati, S.; Roscoe, K.; Rossi, A.M.; Rozen, Y.; Runge, K.; Runolfsson, O.; Rust, D.R.; Sachs, K.; Saeki, T.; Sahr, O.; Sang, W.M.; Sarkisian, E.K.G.; Sbarra, C.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schmitt, S.; Schoning, A.; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Shepherd-Themistocleous, C.H.; Sherwood, P.; Siroli, G.P.; Skuja, A.; Smith, A.M.; Snow, G.A.; Sobie, R.; Soldner-Rembold, S.; Spagnolo, S.; Sproston, M.; Stahl, A.; Stephens, K.; Stoll, K.; Strom, David M.; Strohmer, R.; Surrow, B.; Talbot, S.D.; Tarem, S.; Taylor, R.J.; Teuscher, R.; Thiergen, M.; Thomas, J.; Thomson, M.A.; Torrence, E.; Towers, S.; Trefzger, T.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Van Kooten, Rick J.; Vannerem, P.; Verzocchi, M.; Voss, H.; Waller, D.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wetterling, D.; White, J.S.; Wilson, G.W.; Wilson, J.A.; Wyatt, T.R.; Yamashita, S.; Zacek, V.; Zer-Zion, D.; Jade, The

2000-01-01

We employ data taken by the JADE and OPAL experiments for an integrated QCD study in hadronic e+e- annihilations at c.m.s. energies ranging from 35 GeV through 189 GeV. The study is based on jet-multiplicity related observables. The observables are obtained to high jet resolution scales with the JADE, Durham, Cambridge and cone jet finders, and compared with the predictions of various QCD and Monte Carlo models. The strong coupling strength, alpha_s, is determined at each energy by fits of O(alpha_s^2) calculations, as well as matched O(alpha_s^2) and NLLA predictions, to the data. Matching schemes are compared, and the dependence of the results on the choice of the renormalization scale is investigated. The combination of the results using matched predictions gives alpha_s(MZ)=0.1187+{0.0034}-{0.0019}. The strong coupling is also obtained, at lower precision, from O(alpha_s^2) fits of the c.m.s. energy evolution of some of the observables. A qualitative comparison is made between the data and a recent MLLA p...

Biaxial creep deformation of Zircaloy-4 in the high alpha phase temperature range

International Nuclear Information System (INIS)

Donaldson, A.T.; Horwood, R.A.; Healey, T.

1983-01-01

The ballooning response of Zircaloy-4 fuel tubes during a postulated loss-of-coolant accident may be calculated from a knowledge of the thermal environment of the rods and the creep deformation characteristics of the cladding. In support of such calculations biaxial creep studies have been performed on fuel tubes supplied by Westinghouse, Wolverine and Sandvik of temperatures in the alpha phase range. This paper presents the results of an investigation of their respective creep behaviour which has resulted in the formulation of equations for use in LOCA fuel ballooning codes. (author)

Alpha Momentum and Price Momentum

Directory of Open Access Journals (Sweden)

Hannah Lea Hühn

2018-05-01

Full Text Available We analyze a novel alpha momentum strategy that invests in stocks based on three-factor alphas which we estimate using daily returns. The empirical analysis for the U.S. and for Europe shows that (i past alpha has power in predicting the cross-section of stock returns; (ii alpha momentum exhibits less dynamic factor exposures than price momentum and (iii alpha momentum dominates price momentum only in the U.S. Connecting both strategies to behavioral explanations, alpha momentum is more related to an underreaction to firm-specific news while price momentum is primarily driven by price overshooting due to momentum trading.

Unweighted event generation in hadronic WZ production at order $(\\alpha_{S})$

CERN Document Server

Dobbs, Matt; Lefebvre, Michel

2001-01-01

We present an algorithm for unweighted event generation in the partonic process pp -> WZ (j) with leptonic decays at next-to-leading order in alpha_S. Monte Carlo programs for processes such as this frequently generate events with negative weights in certain regions of phase space. For simulations of experimental data one would like to have unweighted events only. We demonstrate how the phase space from the matrix elements can be combined to achieve unweighted event generation using a second stage Monte Carlo integration over a volume of real emissions (jets). Observable quantities are kept fixed in the laboratory frame throughout the integration. The algorithm is applicable to a broader class of processes and is CPU intensive.

Prediction of phase equilibria in the In–Sb–Pb system

Directory of Open Access Journals (Sweden)

DUSKO MINIC

2008-03-01

Full Text Available Binary thermodynamic data, successfully used for phase diagram calculations of the binary systems In–Sb, Pb–Sb and In–Pb, were used for the prediction of the phase equilibria in the ternary In–Sb–Pb system. The predicted equilibrium phase diagram of the vertical Pb–InSb section was compared with the results of differential thermal analysis DTA and optical microscopy. The calculated phase diagram of the isothermal section at 300 °C was compared with the experimentally (SEM, EDX determined composition of phases in the chosen alloys after annealing. Very good agreement between the binary-based thermodynamic prediction and the experimental data was found in all cases. The calculated liquidus projection of the ternary In–Sb–Pb system is also presented.

Frontal alpha asymmetry predicts inhibitory processing in youth with attention deficit/hyperactivity disorder.

Science.gov (United States)

Ellis, Alissa J; Kinzel, Chantelle; Salgari, Giulia C; Loo, Sandra K

2017-07-28

Atypical asymmetry in brain activity has been implicated in the behavioral and attentional dysregulation observed in ADHD. Specifically, asymmetry in neural activity in the right versus left frontal regions has been linked to ADHD, as well as to symptoms often associated with ADHD such as heightened approach behaviors, impulsivity and difficulties with inhibition. Clarifying the role of frontal asymmetry in ADHD-like traits, such as disinhibition, may provide information on the neurophysiological processes underlying these behaviors. ADHD youth (ADHD: n = 25) and healthy, typically developing controls (TD: n = 25) underwent an electroencephalography (EEG) recording while completing a go/no-go task-a commonly used test measuring behavioral inhibition. In addition, advanced signal processing for source localization estimated the location of signal generators underlying frontal alpha asymmetry (FA) during correct and incorrect trials. This is the first study in ADHD to demonstrate that the dorsal-lateral prefrontal cortex (DLPFC) may be responsible for generating frontal alpha. During failed inhibition trials, ADHD youth displayed greater FA than TD youth. In addition, within the ADHD group, frontal asymmetry during later processing stages (i.e., 400-800ms after stimulus) predicted a higher number of commission errors throughout the task. These results suggest that frontal alpha asymmetry may be a specific biomarker of cognitive disinhibition among youth with ADHD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of coexistent hydrogen isotopes on tracer diffusion of tritium in alpha phase of group-V metal-hydrogen systems

International Nuclear Information System (INIS)

Sakamoto, Kan; Hashizume, Kenichi; Sugisaki, Masayasu

2009-01-01

Tracer diffusion coefficients of tritium in the alpha phase of group-V metal-hydrogen systems, α-MH(D)xTy (M=V and Ta; x>>y), were measured in order to clarify the effects of coexistent hydrogen isotopes on the tritium diffusion behavior. The hydrogen concentration dependence of such behavior and the effects of the coexistent hydrogen isotopes (protium and deuterium) were determined. The results obtained in the present (for V and Ta) and previous (for Nb) studies revealed that tritium diffusion was definitely dependent on hydrogen concentration but was not so sensitive to the kind of coexistent hydrogen isotopes. By summarizing those data, it was found that the hydrogen concentration dependence of the tracer diffusion coefficient of tritium in the alpha phase of group-V metals could be roughly expressed by a single empirical curve. (author)

Theoretical predictions for alpha particle spectroscopic strengths

International Nuclear Information System (INIS)

Draayer, J.P.

1975-01-01

Multinucleon transfers induced in heavy-ion reactions of the type ( 6 Li,d) furnish a selective probe with which to study the interplay between rotational and clustering phenomena so characteristic of the structure of the light sd-shell nuclei. For these nuclei, theoretical predictions for inter-band as well as intra-band transfer strengths can be made using recently tabulated results for angular momentum dependent SU 3 inclusion R 3 relative spectroscopic strengths and angular momentum independent SU 6 inclusion SU 3 coefficients of fractional parentage. The pure SU 3 (oscillator)-SU 4 (supermultiplet) symmetry limit agrees well with results obtained using available eigenfunctions determined in large shell model calculations. In particular, the scalar nature of a transferred ''alpha''-cluster insures that the effect of spatial symmetry admixtures in the initial and final states of the target and residual nuclei are minimized. Sum rule quantities provide a measure of the probable effects of symmetry breaking. Strength variations within a band are expected; transfers to core excited states are often favored. Results extracted from exact finite range DWBA analyses of ( 6 Li,d) data on 16 , 18 O, 20 , 21 , 22 Ne, 24 , 25 Mg show some anomalies in our understanding of the structure and/or reaction mechanisms. (18 figures) (U.S.)

Contribution to the study of alpha-alpha interaction; Contribution a l'etude de l'interaction alpha - alpha

Energy Technology Data Exchange (ETDEWEB)

Darriulai, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-03-01

Two sets of measurements of the {alpha}-{alpha} elastic scattering differential cross section are presented. The first set - angular distributions from 50 up to 120 MeV - shows two new resonances, 6{sup +} and 8{sup +}, at 25 and 57 MeV. Complex phase shifts are extracted from the data and a phenomenological potential is given. A description of the 3 {alpha}-particle 0{sup +} states in C{sup 12} is made with this interaction potential. The second set - excitation curves between 20 and 50 MeV - allows investigation of the Be{sup 8} level structure within this energy range - It identifies the 16.6 and 16.9 MeV states as 2{sup +}, but the rise of inelastic processes at higher energies makes further identification of spins and parities more and more difficult. (author) [French] Deux series de mesures de la section efficace differentielle de diffusion {alpha}-{alpha} sont presentees. La premiere - distributions angulaires entre 50 et 120 MeV - fait apparaitre deux nouvelles resonances, 6{sup +} et 8{sup +}, a 25 et 57 MeV d'excitation. Des dephasages complexes en sont extraits et un potentiel phenomenologique est presente. Une etude des etats 0{sup +} a parentage (3{alpha}) de {sup 12}C est faite a partir de ce potentiel. La seconde - courbes d'excitation s'etendant de 20 a 50 MeV - met en evidence la structure de {sup 8}Be dans cette region. Elle montre que les niveaux a 16,6 et 16,9 MeV sont des 2{sup +} mais l'importance des processus inelastiques rend difficile l'identification des niveaux d'excitation plus elevee. (auteur)

Saccades phase-locked to alpha oscillations in the occipital and medial temporal lobe enhance memory encoding

OpenAIRE

Noachtar, Soheyl; Doeller, Christian; Jensen, Ole; Hartl, Elisabeth; Staudigl, Tobias

2017-01-01

Efficient sampling of visual information requires a coordination of eye movements and ongoing brain oscillations. Using intracranial and MEG recordings, we show that saccades are locked to the phase of visual alpha oscillations, and that this coordination supports mnemonic encoding of visual scenes. Furthermore, parahippocampal and retrosplenial cortex involvement in this coordination reflects effective vision-to-memory mapping, highlighting the importance of neural oscillations for the inter...

Dynamical chaos in a linear 3. alpha. system. Dinamicheskij khaos v linejnoj 3. alpha. -sisteme

Energy Technology Data Exchange (ETDEWEB)

Bolotin, Yu L; Gonchar, V Yu; Chekanov, N A [AN Ukrainskoj SSR, Kharkov (Ukrainian SSR). Fiziko-Tekhnicheskij Inst.; Vinitskij, S I [Joint Inst. for Nuclear Research, Dubna (USSR)

1989-01-01

Classical dynamics of the motion of a molecular model of the carbon nucleus, which is a linear 3{alpha} system with realistic {alpha}{alpha} interaction is studied. Transition from a regular to a chaos motion in the nuclear molecule is shown to occur with growing energy more rapidly than in model problems with polynomial potentials. It is found that in a small region of the phase space the motion remains regular at energies higher than the 3{alpha}-system dissociation threshold. This is probably related to the C{sub 3v}-symmetry violation. Formulas for the quasiclassical spectrum of the 3{alpha} system are obtained with the use of the Birkhoff normal form.

Suppressed Alpha Oscillations Predict Intelligibility of Speech and its Acoustic Details

Science.gov (United States)

Weisz, Nathan

2012-01-01

Modulations of human alpha oscillations (8–13 Hz) accompany many cognitive processes, but their functional role in auditory perception has proven elusive: Do oscillatory dynamics of alpha reflect acoustic details of the speech signal and are they indicative of comprehension success? Acoustically presented words were degraded in acoustic envelope and spectrum in an orthogonal design, and electroencephalogram responses in the frequency domain were analyzed in 24 participants, who rated word comprehensibility after each trial. First, the alpha power suppression during and after a degraded word depended monotonically on spectral and, to a lesser extent, envelope detail. The magnitude of this alpha suppression exhibited an additional and independent influence on later comprehension ratings. Second, source localization of alpha suppression yielded superior parietal, prefrontal, as well as anterior temporal brain areas. Third, multivariate classification of the time–frequency pattern across participants showed that patterns of late posterior alpha power allowed best for above-chance classification of word intelligibility. Results suggest that both magnitude and topography of late alpha suppression in response to single words can indicate a listener's sensitivity to acoustic features and the ability to comprehend speech under adverse listening conditions. PMID:22100354

Analysis of the local kinetics and localization of interleukin-1 alpha, tumour necrosis factor-alpha and transforming growth factor-beta, during the course of experimental pulmonary tuberculosis.

Science.gov (United States)

Hernandez-Pando, R; Orozco, H; Arriaga, K; Sampieri, A; Larriva-Sahd, J; Madrid-Marina, V

1997-01-01

A mouse model of pulmonary tuberculosis induced by the intratracheal instillation of live and virulent mycobacteria strain H37-Rv was used to examine the relationship of the histopathological findings with the local kinetics production and cellular distribution of tumour necrosis factor-alpha (TNF-alpha), interleukin-1 alpha (IL-1 alpha) and transforming growth factor-beta (TGF-beta). The histopathological and immunological studies showed two phases of the disease: acute or early and chronic or advanced. The acute phase was characterized by inflammatory infiltrate in the alveolar-capillary interstitium, blood vessels and bronchial wall with formation of granulomas. During this acute phase, which lasted from 1 to 28 days, high percentages of TNF-alpha and IL-1 alpha immunostained activated macrophages were observed principally in the interstium-intralveolar inflammatory infiltrate and in granulomas. Electron microscopy studies of these cells, showed extensive rough endoplasmic reticulum, numerous lysosomes and occasional mycobacteria. Double labelling with colloid gold showed that TNF-alpha and IL-1 alpha were present in the same cells, but were confined to separate vacuoles near the Golgi area, and mixed in larger vacuoles near to cell membrane. The concentration of TNF-alpha and IL-1 alpha as well as their respective mRNAs were elevated in the early phase, particularly at day 3 when the bacillary count decreased. A second peak was seen at days 14 and 21-28 when granulomas appeared and evolved to full maturation. In contrast, TGF-beta production and numbers of immunoreactive cells were low in comparison with the advanced phase of the disease. The chronic phase was characterized by histopathological changes indicative of more severity (i.e. pneumonia, focal necrosis and extensive interstitial fibrosis) with a decrease in the TNF-alpha and IL-1 alpha production that coincided with the highest level of TGF-beta. The bacillary counts were highest as the macrophages

Nano Size Crystals of Geothite, alpha-FeOOH: Synthesis and Thermal Transformation

Energy Technology Data Exchange (ETDEWEB)

Christensen,A.; Jensen, T.; Bahl, C.; DiMasi, E.

2007-01-01

An aqueous suspension of amorphous iron(III) hydroxide was kept at room temperature (298 K) for 23 years. During this period of time the pH of the liquid phase changed from 4.3 to 2.85, and nano size crystals of goethite, {alpha}-FeOOH crystallized from the amorphous iron(III) hydroxide. Transmission electron microscopy (TEM) investigations, Moessbauer spectra, and powder X-ray diffraction using Co K{alpha} radiation showed that the only iron containing crystalline phase present in the recovered product was {alpha}-FeOOH. The size of these nano particles range from 10 to 100 nm measured by TEM. The thermal decomposition of {alpha}-FeOOH was investigated by time-resolved in situ synchrotron radiation powder X-ray diffraction and the data showed that the sample of {alpha}-FeOOH transformed to {alpha}-Fe{sub 2}O{sub 3} in the temperature range 444--584 K. A quantitative phase analysis shows the increase in scattered X-ray intensity from {alpha}-Fe{sub 2}O{sub 3} to follow the decrease of intensity from {alpha}-FeOOH in agreement with the topotactic phase transition.

A study of solar flare energy transport based on coordinated H-alpha and X-ray observations

International Nuclear Information System (INIS)

Canfield, R.C.; Wulser, J.; Zarro, D.M.; Dennis, B.R.

1991-01-01

The temporal evolution of the ratio between H-alpha to nonthermal hard X-ray emission was investigated using coordinated H-alpha and hard- and soft-X-ray observations of five solar flares (on May 7, June 23, June 24, and June 25, 1980 and on April 30, 1985). These observations were used to estimate the emitted flare energy flux F(H-alpha) in H-alpha, the flux of F(2O) energy deposited by nonthermal electrons with energies above 20 keV, and the pressure p(c) of soft X-ray-emitting plasma as functions of time during the impulsive phase of each flare. It was found that the F(H-alpha)/F(2O) ratio shows a power-law dependence on F(2O), with a slope that differs slightly from that predicted by the static thick-target model of solar transport. Results also indicate that the power-law dependence is modified by hydrostatic pressure effects. 25 refs

Crystalline anhydrous {alpha},{alpha}-trehalose (polymorph {beta}) and crystalline dihydrate {alpha},{alpha}-trehalose: A calorimetric study

Energy Technology Data Exchange (ETDEWEB)

Pinto, Susana S. [Centro de Quimica Estrutural, Complexo Interdisciplinar, Instituto Superior Tecnico, 1049-001 Lisbon (Portugal)]. E-mail: susanapinto@ist.utl.pt; Diogo, Herminio P. [Centro de Quimica Estrutural, Complexo Interdisciplinar, Instituto Superior Tecnico, 1049-001 Lisbon (Portugal)]. E-mail: hdiogo@ist.utl.pt; Moura-Ramos, Joaquim J. [Centro de Quimica-Fisica Molecular, Complexo Interdisciplinar, Instituto Superior Tecnico, 1049-001 Lisbon (Portugal)]. E-mail: mouraramos@ist.utl.pt

2006-09-15

The mean values of the standard massic energy of combustion of crystalline anhydrous {alpha},{alpha}-trehalose (C{sub 12}H{sub 22}O{sub 11}, polymorph {beta}) and crystalline dihydrate {alpha},{alpha}-trehalose (C{sub 12}H{sub 26}O{sub 13}) measured by static-bomb combustion calorimetry in oxygen, at the temperature T=298.15K, are {delta}{sub c}u{sup o}=-(16434.05+/-4.50)J.g{sup -1} and {delta}{sub c}u{sup o}=-(14816.05+/-3.52)J.g{sup -1}, respectively. The standard (p{sup o}=0.1MPa) molar enthalpy of formation of these compounds were derived from the corresponding standard molar enthalpies of combustion, respectively, {delta}{sub f}H{sub m}{sup o} (C{sub 12}H{sub 22}O{sub 11},cr)=-(2240.9+/-3.9)kJ.mol{sup -1}, and {delta}{sub f}H{sub m}{sup o} (C{sub 12}H{sub 26}O{sub 13},cr)=-(2832.6+/-3.6)kJ.mol{sup -1}. The values of the standard enthalpies of formation obtained in this work, together with data on enthalpies of solution at infinite dilution ({delta}{sub sol}H{sup {approx}}) for crystalline dihydrate and amorphous anhydrous trehalose, allow a better insight on the thermodynamic description of the trehalose system which can provide, together with the future research on the subject, a contribution for understanding the metabolism in several organisms, as well as the phase transition between the different polymorphs.

Simultaneous measurement of cholesterol 7 alpha-hydroxylase activity by reverse-phase high-performance liquid chromatography using both endogenous and exogenous [4-14C]cholesterol as substrate

International Nuclear Information System (INIS)

Hylemon, P.B.; Studer, E.J.; Pandak, W.M.; Heuman, D.M.; Vlahcevic, Z.R.; Chiang, J.Y.

1989-01-01

The HPLC-spectrophotometric method for measuring cholesterol 7 alpha-hydroxylase activity was modified by using a C-18 reverse-phase column to separate 7 alpha-hydroxy-4-cholesten-3-one and 4-cholesten-3-one and by adding 7 beta-hydroxycholesterol to each reaction mixture as an internal recovery standard. With this method, we were able to simultaneously measure cholesterol 7 alpha-hydroxylase activity using endogenous cholesterol and exogenous [4- 14 C]cholesterol as substrate. Rat liver cytosol differentially stimulated (286%) the 7 alpha-hydroxylation of exogenous [4- 14 C]-cholesterol. In contrast, total cholesterol 7 alpha-hydroxylase activity was stimulated only 35% by cytosol. This method should prove useful for studying mechanisms of cholesterol delivery to cholesterol 7 alpha-hydroxylase

Attempt of analysis of the elastic scattering of 44 MeV alpha particles using a phase shift parameterization

International Nuclear Information System (INIS)

Papiau, Anne-Marie

1966-01-01

In order to ease the resolution of the problem of interaction of an alpha particle with a nucleus, and determine simpler hypotheses which enable the analysis of experimental results, this research thesis reports the use of a parameterization of phase shifts to reduce ambiguities and the number of parameters. After general remarks, a description of the Hamiltonian and a formulation of phase shifts, the author presents experimental data and the analytical method. Analysis is then performed for two-, three-, four- or five-parameter formulations. Efficient cross sections are then studied

Modeling of mechanical properties in alpha/beta-titanium alloys

Science.gov (United States)

Kar, Sujoy Kumar

2005-11-01

The accelerated insertion of titanium alloys in component application requires the development of predictive capabilities for various aspects of their behavior, for example, phase stability, microstructural evolution and property-microstructure relationships over a wide range of length and time scales. In this presentation some navel aspects of property-microstructure relationships and microstructural evolution in alpha/beta Ti alloys will be discussed. Neural Network (NN) Models based on a Bayesian framework have been developed to predict the mechanical properties of alpha/beta Ti alloys. The development of such rules-based model requires the population of extensive databases, which in the present case are microstructurally-based. The steps involved in database development include producing controlled variations of the microstructure using novel approaches to heat-treatments, the use of standardized stereology protocols to characterize and quantify microstructural features rapidly, and mechanical testing of the heat-treated specimens. These databases have been used to train and test NN Models for prediction of mechanical properties. In addition, these models have been used to identify the influence of individual microstructural features on the mechanical properties, consequently guiding the efforts towards development of more robust mechanistically based models. In order to understand the property-microstructure relationships, a detailed understanding of microstructure evolution is imperative. The crystallography of the microstructure developing as a result of the solid-state beta → beta+alpha transformation has been studied in detail by employing Scanning Electron Microscopy (SEM), Orientation Imaging Microscopy (in a high resolution SEM), site-specific TEM sample preparation using focused ion beam, and TEM based techniques. The influence of variant selection on the evolution of microstructure will be specifically addressed.

Novel chemistry of alpha-tosyloxy ketones: applications to the solution- and solid-phase synthesis of privileged heterocycle and enediyne libraries

DEFF Research Database (Denmark)

Nicolaou, K C; Montagnon, T; Ulven, T

2002-01-01

New synthetic technologies for the preparation and elaboration of alpha-tosyloxy ketones in solution- and on solid-phase are described. Both olefins and ketones serve as precursors to these relatively stable chemical entities: olefins via a novel one-pot epoxidation, arylsulfonic acid displacemen...

Addition of iron for the removal of the {beta}-AlFeSi intermetallic by refining of {alpha}-AlFeSi phase in an Al-7.5Si-3.6Cu alloy

Energy Technology Data Exchange (ETDEWEB)

Belmares-Perales, S. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico); Zaldivar-Cadena, A.A., E-mail: azaldiva70@hotmail.com [Facultad de Ingenieria Civil, Departamento de Ecomateriales y Energia, Instituto de Ingenieria Civil, Av. Fidel Velasquez and Av. Universidad S/N, Cd. Universitaria, San Nicolas de los Garza, N.L. 66450 (Mexico)

2010-10-25

Addition of iron into the molten metal for the removal of the {beta}-AlFeSi intermetallic by refining of {alpha}-AlFeSi phase has been studied. Solidification conditions and composition determine the final microstructure and mechanical properties of a casting piece. It is known that increasing the iron content will produce an increasing of the {alpha}-AlFeSi and {beta}-AlFeSi phases. This phenomenon was confirmed with calculations made by Thermo-Calc{sup TM} software and validated with experimental results, however, the technique of iron addition in this study plays an important role on the solidification kinetics of these iron phases because the refining of {alpha}-AlFeSi and removal of {beta}-AlFeSi phases can be improved. Final results showed an improvement in mechanical properties by removal and refining of {beta}-AlFeSi and {alpha}-AlFeSi phases, respectively. This study shows a new method of removal of {beta}-AlFeSi that could be adopted in the aluminum smelting industry in aluminum alloys with a low cooling rate with a secondary dendritic spacing of about 37 {mu}m.

DETERMINATION OF MUSHROOM TOXIN ALPHA-AMANITIN IN SERUM BY LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY AFTER SOLID-PHASE EXTRACTION

Directory of Open Access Journals (Sweden)

Maja Vujović

2015-03-01

Full Text Available Alpha-amanitin is a cyclic peptide which belongs to a large group of mushroom toxins known as amatoxins. Being responsible for the majority of fatal mushroom poisonings, they require rapid detection and excretion from the body fluids. In accordance with these requirements, a simple and an accurate method was developed for successful identification and quantification of alpha-amanitin in serum with electrospray liquid chromatography–mass spectrometry (LC-ESI-MS after collision-induced dissociation. The method conforms to the established International Conference on Harmonization Q2A/Q2B 1996 guidelines on the validation of analytical methods. Linearity, precision, extraction recovery and stability test on blank serum spiked with alpha-amanitin and stored in different conditions met the acceptance criteria. The obtained calibration curve was linear over the concentration range 5-100 ng/mL with a lower limit of quantification (LOQ of 5 ng/mL and limit of detection (LOD of 2.5 ng/mL. The mean intra- and inter-day precision and accuracy were 6.05% and less than ±15% of nominal values, respectively. The neutral solid phase extraction with copolymer hydrophilic–lipophilic balance cartridges was found optimal for sample preparation with the mean recovery of 91.94%. The proposed method demonstrated high sensitivity and selectivity which can be useful both for clinical and forensic toxicology analysis of alpha-amanitin at low concentrations.

X-radiation /E greater than 10 keV/, H-alpha and microwave emission during the impulsive phase of solar flares.

Science.gov (United States)

Vorpahl, J. A.

1972-01-01

A study has been made of the variation in hard (E greater than 10 keV) X-radiation, H-alpha and microwave emission during the impulsive phase of solar flares. Analysis shows that the rise-time in the 20-30-keV X-ray spike depends on the electron hardness. The impulsive phase is also marked by an abrupt, very intense increase in H-alpha emission in one or more knots of the flare. Properties of these H-alpha kernels include: (1) a luminosity several times greater than the surrounding flare, (2) an intensity rise starting about 20-30 sec before, peaking about 20-25 sec after, and lasting about twice as long as the hard spike, (3) a location lower in the chromosphere than the remaining flare, (4) essentially no expansion prior to the hard spike, and (5) a position within 6000 km of the boundary separating polarities, usually forming on both sides of the neutral line near both feet of the same tube of force. Correspondingly, impulsive microwave events are characterized by: (1) great similarity in burst structure with 20-32 keV X-rays but only above 5000 MHz, (2) typical low frequency burst cutoff between 1400-3800 MHz, and (3) maximum emission above 7500 MHz.

Serum concentrations of interleukin-1 alpha, interleukin-6 and tumor necrosis factor-alpha in neonatal sepsis and meningitis

International Nuclear Information System (INIS)

Fida, Nadia M.; Fadelallah, Mohamed F.; Al-Mughales, Jamil A.

2006-01-01

To investigate whether serum levels of interleukin-1alpha (IL-1alpha), IL-6, tumor necrosis factor alpha (TNF-alpha), C-reactive protein (CRP) are useful in the diagnosis of neonatal sepsis and meningitis and differentiate them. Blood samples were collected from 35 full term neonates with suspected infection who admitted to the Neonatology Unit, Pediatric Department, King Abdul-Aziz University Hospital, Jeddah, Saudi Arabia during January 2002 - June 2003. On the basis of laboratory and bacteriological results, newborns were classified into: sepsis (n=28), meningitis (n=7), and healthy controls (n=16). Sepsis groups were further subdivided according to culture results into: group 1 = proven sepsis (n=6), group 2 = clinical sepsis (n=14), and group 3 = possible-infected (n=8). Serum levels of IL-1alpha, IL-6, TNF-alpha were measured using Enzyme-Linked Immunosorbent Assay while CRP by nephelometer: In sepsis and meningitis patients, serum levels of CRP (p<0.01, p<0.05,) and IL-1alpha (p<0.001, p<0.05) were elevated than controls. C-reactive protein levels elevated in proven sepsis (p<0.001) and IL-1alpha elevated in all subgroups of sepsis (groups 1, 2, 3) compared with (p<0.05, p<0.001, p<0.01) controls. Interleukin-6, TNF-alpha showed no significant differences between studied groups. In sepsis and meningitis, IL-1alpha had a highest sensitivity (89%, 86%), and negative predictive values (89% and 93%). Interleukin-1alpha and CRP increased in neonatal sepsis and meningitis, but cannot differentiate between them. Interleukin-1alpha had a highest sensitivity in prediction of neonatal infection and its assessment may improve accuracy of diagnosis. (author)

Different responses of spontaneous and stimulus-related alpha activity to ambient luminance changes.

Science.gov (United States)

Benedetto, Alessandro; Lozano-Soldevilla, Diego; VanRullen, Rufin

2017-12-04

Alpha oscillations are particularly important in determining our percepts and have been implicated in fundamental brain functions. Oscillatory activity can be spontaneous or stimulus-related. Furthermore, stimulus-related responses can be phase- or non-phase-locked to the stimulus. Non-phase-locked (induced) activity can be identified as the average amplitude changes in response to a stimulation, while phase-locked activity can be measured via reverse-correlation techniques (echo function). However, the mechanisms and the functional roles of these oscillations are far from clear. Here, we investigated the effect of ambient luminance changes, known to dramatically modulate neural oscillations, on spontaneous and stimulus-related alpha. We investigated the effect of ambient luminance on EEG alpha during spontaneous human brain activity at rest (experiment 1) and during visual stimulation (experiment 2). Results show that spontaneous alpha amplitude increased by decreasing ambient luminance, while alpha frequency remained unaffected. In the second experiment, we found that under low-luminance viewing, the stimulus-related alpha amplitude was lower, and its frequency was slightly faster. These effects were evident in the phase-locked part of the alpha response (echo function), but weaker or absent in the induced (non-phase-locked) alpha responses. Finally, we explored the possible behavioural correlates of these modulations in a monocular critical flicker frequency task (experiment 3), finding that dark adaptation in the left eye decreased the temporal threshold of the right eye. Overall, we found that ambient luminance changes impact differently on spontaneous and stimulus-related alpha expression. We suggest that stimulus-related alpha activity is crucial in determining human temporal segmentation abilities. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Auditory conflict resolution correlates with medial-lateral frontal theta/alpha phase synchrony.

Science.gov (United States)

Huang, Samantha; Rossi, Stephanie; Hämäläinen, Matti; Ahveninen, Jyrki

2014-01-01

When multiple persons speak simultaneously, it may be difficult for the listener to direct attention to correct sound objects among conflicting ones. This could occur, for example, in an emergency situation in which one hears conflicting instructions and the loudest, instead of the wisest, voice prevails. Here, we used cortically-constrained oscillatory MEG/EEG estimates to examine how different brain regions, including caudal anterior cingulate (cACC) and dorsolateral prefrontal cortices (DLPFC), work together to resolve these kinds of auditory conflicts. During an auditory flanker interference task, subjects were presented with sound patterns consisting of three different voices, from three different directions (45° left, straight ahead, 45° right), sounding out either the letters "A" or "O". They were asked to discriminate which sound was presented centrally and ignore the flanking distracters that were phonetically either congruent (50%) or incongruent (50%) with the target. Our cortical MEG/EEG oscillatory estimates demonstrated a direct relationship between performance and brain activity, showing that efficient conflict resolution, as measured with reduced conflict-induced RT lags, is predicted by theta/alpha phase coupling between cACC and right lateral frontal cortex regions intersecting the right frontal eye fields (FEF) and DLPFC, as well as by increased pre-stimulus gamma (60-110 Hz) power in the left inferior fontal cortex. Notably, cACC connectivity patterns that correlated with behavioral conflict-resolution measures were found during both the pre-stimulus and the pre-response periods. Our data provide evidence that, instead of being only transiently activated upon conflict detection, cACC is involved in sustained engagement of attentional resources required for effective sound object selection performance.

Auditory Conflict Resolution Correlates with Medial–Lateral Frontal Theta/Alpha Phase Synchrony

Science.gov (United States)

Huang, Samantha; Rossi, Stephanie; Hämäläinen, Matti; Ahveninen, Jyrki

2014-01-01

When multiple persons speak simultaneously, it may be difficult for the listener to direct attention to correct sound objects among conflicting ones. This could occur, for example, in an emergency situation in which one hears conflicting instructions and the loudest, instead of the wisest, voice prevails. Here, we used cortically-constrained oscillatory MEG/EEG estimates to examine how different brain regions, including caudal anterior cingulate (cACC) and dorsolateral prefrontal cortices (DLPFC), work together to resolve these kinds of auditory conflicts. During an auditory flanker interference task, subjects were presented with sound patterns consisting of three different voices, from three different directions (45° left, straight ahead, 45° right), sounding out either the letters “A” or “O”. They were asked to discriminate which sound was presented centrally and ignore the flanking distracters that were phonetically either congruent (50%) or incongruent (50%) with the target. Our cortical MEG/EEG oscillatory estimates demonstrated a direct relationship between performance and brain activity, showing that efficient conflict resolution, as measured with reduced conflict-induced RT lags, is predicted by theta/alpha phase coupling between cACC and right lateral frontal cortex regions intersecting the right frontal eye fields (FEF) and DLPFC, as well as by increased pre-stimulus gamma (60–110 Hz) power in the left inferior fontal cortex. Notably, cACC connectivity patterns that correlated with behavioral conflict-resolution measures were found during both the pre-stimulus and the pre-response periods. Our data provide evidence that, instead of being only transiently activated upon conflict detection, cACC is involved in sustained engagement of attentional resources required for effective sound object selection performance. PMID:25343503

Auditory conflict resolution correlates with medial-lateral frontal theta/alpha phase synchrony.

Directory of Open Access Journals (Sweden)

Samantha Huang

Full Text Available When multiple persons speak simultaneously, it may be difficult for the listener to direct attention to correct sound objects among conflicting ones. This could occur, for example, in an emergency situation in which one hears conflicting instructions and the loudest, instead of the wisest, voice prevails. Here, we used cortically-constrained oscillatory MEG/EEG estimates to examine how different brain regions, including caudal anterior cingulate (cACC and dorsolateral prefrontal cortices (DLPFC, work together to resolve these kinds of auditory conflicts. During an auditory flanker interference task, subjects were presented with sound patterns consisting of three different voices, from three different directions (45° left, straight ahead, 45° right, sounding out either the letters "A" or "O". They were asked to discriminate which sound was presented centrally and ignore the flanking distracters that were phonetically either congruent (50% or incongruent (50% with the target. Our cortical MEG/EEG oscillatory estimates demonstrated a direct relationship between performance and brain activity, showing that efficient conflict resolution, as measured with reduced conflict-induced RT lags, is predicted by theta/alpha phase coupling between cACC and right lateral frontal cortex regions intersecting the right frontal eye fields (FEF and DLPFC, as well as by increased pre-stimulus gamma (60-110 Hz power in the left inferior fontal cortex. Notably, cACC connectivity patterns that correlated with behavioral conflict-resolution measures were found during both the pre-stimulus and the pre-response periods. Our data provide evidence that, instead of being only transiently activated upon conflict detection, cACC is involved in sustained engagement of attentional resources required for effective sound object selection performance.

Liquid scintillation alpha spectrometry techniques

International Nuclear Information System (INIS)

McKlveen, J.W.; McDowell, W.J.

1984-01-01

Accurate, quantitative determinations of alpha emitting nuclides by conventional plate counting methods are difficult, because of sample self-absorption problems in counting and because of non-reproducible losses in conventional sample separation methods. Liquid scintillation alpha spectrometry offers an attractive alternative with no sample self-absorption or geometry problems and with 100% counting efficiency. Sample preparation may include extraction of the alpha emitter of interest by a specific organic phase-soluble compound directly into the liquid scintillation counting medium. Detection electronics use energy and pulse-shape discrimination, to yield alpha spectra without beta and gamma background interference. Specific procedures have been developed for gross alpha, uranium, plutonium, thorium and colonium assay. Possibilities for a large number of other applications exist. Accuracy and reproducibility are typically in the 1% range. Backgrounds of the order of 0.01 cpm are readily achievable. The paper will present an overview of liquid scintillation alpha counting techniques and some of the results achieved for specific applications. (orig.)

Alpha particle losses during sawtooth activity in Tokamaks

International Nuclear Information System (INIS)

Anderson, D.; Lisak, M.

1988-01-01

The time evolution of the direct losses of fusion produced alpha particles in Tokamak plasmas characterized by sawtooth activity is investigated. The alpha particle loss rate during a sawtooth period is predicted to change invertedly with the change in bulk plasma parameters but also to contain a characteristic burst at the sawtooth crash. The spectrum of the lost alpha particles is also discussed. The predictions for the time evolution and the spectrum of the losses are in qualitative agreement with recently obtained losses of 15 MeV fusion produced protons in JET. (authors)

Characterization of Schottky barrier diodes fabricated from electrochemical oxidation of {alpha} phase brass

Energy Technology Data Exchange (ETDEWEB)

Bond, John W., E-mail: jwb13@le.ac.u [Forensic Research Centre, University of Leicester, Leicester LE1 7 EA (United Kingdom)

2011-04-01

By careful selection of chloride ion concentration in aqueous sodium chloride, electrochemical oxidation of {alpha} phase brass is shown to permit fabrication of either p-type copper (I) oxide/metal or n-type zinc oxide/metal Schottky barrier diodes. X-ray photoelectron and Auger electron spectroscopies provide evidence that barrier formation and rectifying qualities depend on the relative surface abundance of copper (I) oxide and zinc oxide. X-ray diffraction of the resulting diodes shows polycrystalline oxides embedded in amorphous oxidation products that have a lower relative abundance than the diode forming oxide. Conventional I/V characteristics of these diodes show good rectifying qualities. When neither of the oxides dominate, the semiconductor/metal junction displays an absence of rectification.

Contribution to the study of the sintering of ex-carbonyl iron in the {alpha} and {gamma} phases using the micro-fractographic technique; Contribution a l'etude du frittage du fer ex-carbonyle en phases {alpha} et {gamma} par examen des surfaces de rupture au microscope electronique

Energy Technology Data Exchange (ETDEWEB)

Oxley Gaborit de Montjou, M.Th. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-07-01

The micro-fractographic study of the sintering of ex-carbonyl iron has shown or confirmed a number of phenomena of which the principal are as followed: Sintering in the a phase: -) existence of two stages of sintering differentiated by the type of rupture (inter or trans-crystalline); -) marked influence of the content of oxygen in the atmosphere and in the initial compressed sample on the speed of sintering; -) formation of striations on the grain-boundary surfaces and on the inner surface of pores caused by the presence of oxygen. Sintering in the {gamma} phase: -) a pronounced decrease in the speed of sintering: the grains in the initial powder remain in the granular state within the final {alpha} crystal in the iron sintered in the lower {gamma} range even after several hours of sintering; -) this granular structure can be eliminated by intermediate compression thus enabling the sintering process to proceed. A considerable decrease in the speed of sintering if the A{sub 3} point is passed one or more times in the {alpha} range sintering. A high speed sintering if the treatment in the {gamma} range is carried out at or above 1300 C. The results of this study agree with micrographic investigation as well as with dilatometric measurements and known auto-diffusion coefficients. (author) [French] L'etude microfractographique du frittage du fer ex-carbonyle a permis de mettre en evidence ou verifier plusieurs phenomenes dont les principaux sont les suivants: Pour le frittoge en phase {alpha}: -) existence de deux stades de frittage differencies par le type de rupture (inter et transcristalline); -) importance de la teneur en oxygene dans l'atmosphere et dans le comprime initial sur la vitesse de frittage; -) formation de stries dues a la presence d'oxygene sur les plans de joints et a l'interieur des pores. Pour le frittage en phase {gamma}: -) un ralentissement tres prononce de la cinetique du frittage: les granules de la poudre initiale demeurent a l'etat de

Determination of $\\alpha_{s}$ using Jet Rates at LEP with the OPAL detector

CERN Document Server

Abbiendi, G.; Akesson, P.F.; Alexander, G.; Anagnostou, G.; Anderson, K.J.; Asai, S.; Axen, D.; Bailey, I.; Barberio, E.; Barillari, T.; Barlow, R.J.; Batley, R.J.; Bechtle, P.; Behnke, T.; Bell, Kenneth Watson; Bell, P.J.; Bella, G.; Bellerive, A.; Benelli, G.; Bethke, S.; Biebel, O.; Boeriu, O.; Bock, P.; Boutemeur, M.; Braibant, S.; Brown, Robert M.; Burckhart, H.J.; Campana, S.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, D.G.; Ciocca, C.; Csilling, A.; Cuffiani, M.; Dado, S.; De Roeck, A.; De Wolf, E.A.; Desch, K.; Dienes, B.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Etzion, E.; Fabbri, F.; Ferrari, P.; Fiedler, F.; Fleck, I.; Ford, M.; Frey, A.; Gagnon, P.; Gary, John William; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Giunta, Marina; Goldberg, J.; Gross, E.; Grunhaus, J.; Gruwe, M.; Gunther, P.O.; Gupta, A.; Hajdu, C.; Hamann, M.; Hanson, G.G.; Harel, A.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herten, G.; Heuer, R.D.; Hill, J.C.; Horvath, D.; Igo-Kemenes, P.; Ishii, K.; Jeremie, H.; Jovanovic, P.; Junk, T.R.; Kanzaki, J.; Karlen, D.; Kawagoe, K.; Kawamoto, T.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kluth, S.; Kobayashi, T.; Kobel, M.; Komamiya, S.; Kramer, T.; Krasznahorkay, A.; Krieger, P.; von Krogh, J.; Kuhl, T.; Kupper, M.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Lellouch, D.; Lettso, J.; Levinson, L.; Lillich, J.; Lloyd, S.L.; Loebinger, F.K.; Lu, J.; Ludwig, A.; Ludwig, J.; Mader, W.; Marcellini, S.; Martin, A.J.; Mashimo, T.; Mattig, Peter; McKenna, J.; McPherson, R.A.; Meijers, F.; Menges, W.; Merritt, F.S.; Mes, H.; Meyer, Niels T.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Mohr, W.; Mori, T.; Mutter, A.; Nagai, K.; Nakamura, I.; Nanjo, H.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oh, A.; Oreglia, M.J.; Orito, S.; Pahl, C.; Pasztor, G.; Pater, J.R.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Pooth, O.; Przybycien, M.; Quadt, A.; Rabbertz, K.; Rembser, C.; Renkel, P.; Roney, J.M.; Rossi, A.M.; Rozen, Y.; Runge, K.; Sachs, K.; Saeki, T.; Sarkisyan, E.K.G.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schorner-Sadenius, T.; Schroder, Matthias; Schumacher, M.; Seuster, R.; Shears, T.G.; Shen, B.C.; Sherwood, P.; Skuja, A.; Smith, A.M.; Sobie, R.; Soldner-Rembold, S.; Spano, F.; Stahl, A.; Strom, David M.; Strohmer, R.; Tarem, S.; Tasevsky, M.; Teuscher, R.; Thomson, M.A.; Torrence, E.; Toya, D.; Tran, P.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Ujvari, B.; Vollmer, C.F.; Vannerem, P.; Vertesi, R.; Verzocchi, M.; Voss, H.; Vossebeld, J.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wilson, G.W.; Wilson, J.A.; Wolf, G.; Wyatt, T.R.; Yamashita, S.; Zer-Zion, D.; Zivkovic, Lidija

2006-01-01

Hadronic events produced in e+e- collisions by the LEP collider and recorded by the OPAL detector were used to form distributions based on the number of reconstructed jets. The data were collected between 1995 and 2000 and correspond to energies of 91 GeV, 130-136 GeV and 161-209 GeV. The jet rates were determined using four different jet-finding algorithms (Cone, JADE, Durham and Cambridge). The differential two-jet rate and the average jet rate with the Durham and Cambridge algorithms were used to measure alpha(s) in the LEP energy range by fitting an expression in which order alpah_2s calculations were matched to a NLLA prediction and fitted to the data. Combining the measurements at different centre-of-mass energies, the value of alpha_s (Mz) was determined to be alpha(s)(Mz)=0.1177+-0.0006(stat.)+-0.0012$(expt.)+-0.0010(had.)+-0.0032

Decrease in early right alpha band phase synchronization and late gamma band oscillations in processing syntax in music.

Science.gov (United States)

Ruiz, María Herrojo; Koelsch, Stefan; Bhattacharya, Joydeep

2009-04-01

The present study investigated the neural correlates associated with the processing of music-syntactical irregularities as compared with regular syntactic structures in music. Previous studies reported an early ( approximately 200 ms) right anterior negative component (ERAN) by traditional event-related-potential analysis during music-syntactical irregularities, yet little is known about the underlying oscillatory and synchronization properties of brain responses which are supposed to play a crucial role in general cognition including music perception. First we showed that the ERAN was primarily represented by low frequency (music-syntactical irregularities as compared with music-syntactical regularities, were associated with (i) an early decrease in the alpha band (9-10 Hz) phase synchronization between right fronto-central and left temporal brain regions, and (ii) a late ( approximately 500 ms) decrease in gamma band (38-50 Hz) oscillations over fronto-central brain regions. These results indicate a weaker degree of long-range integration when the musical expectancy is violated. In summary, our results reveal neural mechanisms of music-syntactic processing that operate at different levels of cortical integration, ranging from early decrease in long-range alpha phase synchronization to late local gamma oscillations. 2008 Wiley-Liss, Inc.

A detector module with highly efficient surface-alpha event rejection operated in CRESST-II Phase 2

Energy Technology Data Exchange (ETDEWEB)

Strauss, R. [Max-Planck-Institut fuer Physik, Munich (Germany); Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Angloher, G.; Ferreiro, N.; Hauff, D.; Kiefer, M.; Petricca, F.; Proebst, F.; Reindl, F.; Seidel, W.; Stodolsky, L.; Tanzke, A.; Wuestrich, M. [Max-Planck-Institut fuer Physik, Munich (Germany); Bento, A. [Universidade de Coimbra, CIUC, Departamento de Fisica, Coimbra (Portugal); Bucci, C.; Canonica, L.; Gorla, P.; Schaeffner, K. [Laboratori Nazionali del Gran Sasso, INFN, Assergi (Italy); Erb, A. [Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Walther-Meissner-Institut fuer Tieftemperaturforschung, Garching (Germany); Feilitzsch, F. von; Guetlein, A.; Lanfranchi, J.C.; Muenster, A.; Potzel, W.; Roth, S.; Schoenert, S.; Stanger, M.; Ulrich, A.; Wawoczny, S.; Willers, M.; Zoeller, A. [Technische Universitaet Muenchen, Physik-Department, Garching (Germany); Jochum, J.; Loebell, J.; Rottler, K.; Sailer, C.; Scholl, S.; Strandhagen, C.; Uffinger, M.; Usherov, I. [Eberhard-Karls-Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Kluck, H. [Institut fuer Hochenergiephysik der Oesterreichischen Akademie der Wissenschaften, Wien (Austria); Vienna University of Technology, Atominstitut, Wien (Austria); Kraus, H. [University of Oxford, Department of Physics, Oxford (United Kingdom); Schieck, J. [Institut fuer Hochenergiephysik der Oesterreichischen Akademie der Wissenschaften, Wien (Austria); Sivers, M. von [Technische Universitaet Muenchen, Physik-Department, Garching (Germany); University of Bern, Albert Einstein Center for Fundamental Physics, Bern (Switzerland)

2015-08-15

The cryogenic dark matter experiment CRESSTII aims at the direct detection of WIMPs via elastic scattering off nuclei in scintillating CaWO{sub 4} crystals. We present a new, highly improved, detector design installed in the current run of CRESST-II Phase 2 with an efficient active rejection of surface-alpha backgrounds. Using CaWO{sub 4} sticks instead of metal clamps to hold the target crystal, a detector housing with fully-scintillating inner surface could be realized. The presented detector (TUM40) provides an excellent threshold of ∝0.60 keV and a resolution of σ ∼ 0.090 keV (at 2.60 keV).With significantly reduced background levels, TUM40 sets stringent limits on the spin-independent WIMP nucleon scattering cross section and probes a new region of parameter space for WIMP masses below 3GeV/c{sup 2}. In this paper, we discuss the novel detector design and the surface-alpha event rejection in detail. (orig.)

Different slopes for different folks: alpha and delta EEG power predict subsequent video game learning rate and improvements in cognitive control tasks.

Science.gov (United States)

Mathewson, Kyle E; Basak, Chandramallika; Maclin, Edward L; Low, Kathy A; Boot, Walter R; Kramer, Arthur F; Fabiani, Monica; Gratton, Gabriele

2012-12-01

We hypothesized that control processes, as measured using electrophysiological (EEG) variables, influence the rate of learning of complex tasks. Specifically, we measured alpha power, event-related spectral perturbations (ERSPs), and event-related brain potentials during early training of the Space Fortress task, and correlated these measures with subsequent learning rate and performance in transfer tasks. Once initial score was partialled out, the best predictors were frontal alpha power and alpha and delta ERSPs, but not P300. By combining these predictors, we could explain about 50% of the learning rate variance and 10%-20% of the variance in transfer to other tasks using only pretraining EEG measures. Thus, control processes, as indexed by alpha and delta EEG oscillations, can predict learning and skill improvements. The results are of potential use to optimize training regimes. Copyright © 2012 Society for Psychophysiological Research.

Coordinated soft X-ray and H-alpha observation of solar flares

Science.gov (United States)

Zarro, D. M.; Canfield, R. C.; Metcalf, T. R.; Lemen, J. R.

1988-01-01

Soft X-ray, Ca XIX, and H-alpha observations obtained for a set of four solar flares in the impulsive phase are analyzed. A blue asymmetry was observed in the coronal Ca XIX line during the soft-Xray rise phase in all of the events. A red asymmetry was observed simultaneously in chromospheric H-alpha at spatial locations associated with enhanced flare heating. It is shown that the impulsive phase momentum of upflowing soft X-ray plasma equalled that of the downflowing H-alpha plasma to within an order of magnitude. This supports the explosive chromospheric evaporation model of solar flares.

Anomalous loss of DT alpha particles in the Tokamak Fusion Test Reactor

Energy Technology Data Exchange (ETDEWEB)

Herrmann, Hans W. [Princeton Univ., NJ (United States)

1997-09-01

An escaping alpha collector probe has been developed for TFTR`s DT phase. Energy distributions of escaping alphas have been determined by measuring the range of α-particles implanted into nickel foils located within the alpha collector. Results at 1.0 MA of plasma current are in good agreement with predictions for first orbit alpha loss. Results at 1.8 MA, however, show a significant anomalous loss of partially thermalized alphas (in addition to the expected first orbit loss), which is not observed with the lost alpha scintillator detectors in DT plasmas, but does resemble the anomalous delayed loss seen in DD plasmas. None of the candidate explanations proposed thus far are fully consistent with the anomalous loss observations. An experiment designed to study the effect of plasma major radius shifts on α-particle loss has led to a better understanding of α-particle dynamics in tokamaks. Intuitively, one might suppose that confined marginally passing α-particles forced to move toward higher magnetic field during an inward major radius shift (i.e., compression) would mirror and become trapped particles, leading to increased alpha loss. Such an effect was looked for during the shift experiment, however, no significant changes in alpha loss to the 90° lost alpha scintillator detector were observed during the shifts. It is calculated that the energy gained by an α-particle during the inward shift is sufficient to explain this result. However, an unexpected loss of partially thermalized α-particles near the passing/trapped boundary was observed to occur between inward and outward shifts at an intermediate value of plasma current (1.4 MA). This anomalous loss feature is not yet understood.

Alpha5beta1 integrin-fibronectin interactions specify liquid to solid phase transition of 3D cellular aggregates.

Directory of Open Access Journals (Sweden)

Carlos E Caicedo-Carvajal

2010-07-01

Full Text Available Tissue organization during embryonic development and wound healing depends on the ability of cells on the one hand to exchange adhesive bonds during active rearrangement and on the other to become fixed in place as tissue homeostasis is reached. Cells achieve these contradictory tasks by regulating either cell-cell adhesive bonds, mediated by cadherins, or cell-extracellular matrix (ECM connections, regulated by integrins. Integrin alpha5beta1 and soluble fibronectin (sFN are key players in cell-ECM force generation and in ECM polymerization. Here, we explore the interplay between integrin alpha5beta1 and sFN and its influence on tissue mechanical properties and cell sorting behavior.We generated a series of cell lines varying in alpha5beta1 receptor density. We then systematically explored the effects of different sFN concentrations on aggregate biomechanical properties using tissue surface tensiometry. We found previously unreported complex behaviors including the observation that interactions between fibronectin and integrin alpha5beta1 generates biphasic tissue cohesion profiles. Specifically, we show that at constant sFn concentration, aggregate cohesion increases linearly as alpha5beta1 receptor density is increased from low to moderate levels, producing a transition from viscoelastic-liquid to pseudo viscoelastic-solid behavior. However, further increase in receptor density causes an abrupt drop in tissue cohesion and a transition back to viscoelastic-liquid properties. We propose that this may be due to depletion of sFn below a critical value in the aggregate microenvironment at high alpha5beta1 levels. We also show that differential expression of alpha5beta1 integrin can promote phase-separation between cells.The interplay between alpha5-integrin and sFn contributes significantly to tissue cohesion and, depending on their level of expression, can mediate a shift from liquid to elastic behavior. This interplay represents a tunable level

Study of ({alpha}, {sup 3}He) and ({alpha}, t) reactions on {sup 28}Si at 45 MeV

Energy Technology Data Exchange (ETDEWEB)

Darshan, V.P.; Sathyavathiamma, M.P.; Ramaswamy, C.R.; Raja Rao, M.; Puttaswamy, N.G.; Banerjee, S.R.; Chintalapudi, S.N. [Dept. of Phys., Bangalore Univ. (India)

1995-03-01

The {sup 28}Si({alpha}, {sup 3}He){sup 29}Si, {sup 28}Si({alpha}, t){sup 29}P and Si({alpha}, {alpha})Si reactions were studied at E{sub {alpha}} = 45 MeV. Exact finite-range (EFR) DWBA analysis was carried out for the transitions to the ground state and to five excited states in {sup 29}Si and {sup 29}P. Spectroscopic strengths G were extracted for all the states and were compared with the predictions from shell-model and quasi-particle core-coupling calculations. Similar EFR-DWBA analyses were carried out from available (unpublished) data for the {sup 28}Si({alpha}, {sup 3}He){sup 29}Si reaction at E{sub {alpha}} = 64.9 and 120 MeV, and for the {sup 28}Si({alpha}, t){sup 29}P reaction at E{sub {alpha}} = 50 and 64.9 MeV. The comparison of experimental and theoretical values of G are provided. (author)

Diagnostic value of alpha-fetoprotein in liver cancer

International Nuclear Information System (INIS)

Pervez, T.; Anwar, S.M.

2001-01-01

Objective: To determine diagnostic value of alpha-fetoproteins (alpha-FP) in liver cancer. Design: Prospective study. Place and duration of study: Department of clinical oncology services Hospital Lahore, during the period from February 1998 to February 2001. Subjects and Methods: Among 200 persons studied, 100 presented with liver mass, jaundice and other symptoms directing toward liver pathology, later confirmed histopathologically, as suffering from hepatocellular carcinoma (HCC) while the other 100 healthy subject came to the department for blood donation and were HBs Ag pasitive on blood screening. All these subjects under went blood test for alpha-FP. This tumor marker was analyzed by using enzyme immunoassay-based kit. Results: The alpha-FP positivity was statistically evaluated. In HCC this test was statistically significant with p value of <0.001. In this study sensitivity of alpha-FP was 72% specificity 89%, positive predictive value 86.7% and negative predictive value of 76.1%. Conclusion: This study showed that alpha-FP was a useful diagnostic tool in the diagnosis of HCC. (author)

Microstructure evolution and microstructure/mechanical properties relationships in alpha+beta titanium alloys

Science.gov (United States)

Lee, Eunha

In this study, the microstructural evolution of Timetal 550 was investigated. Timetal 550 showed two types of phase transformations (martensitic and nucleation and growth) depending on the cooling rate from the beta region. The alpha phase initially precipitated at the prior beta grain boundaries, and it had a Burgers OR with one of the adjacent grains. It was found that colonies could grow, even in the fast-cooled Timetal 550 sample, from the grain boundary alpha into the prior beta grain with which it exhibited the Burgers OR. Three orientation relationships were also found between alpha laths in the basketweave microstructure. Microhardness testing demonstrated that fast-cooled Timetal 550 samples with basketweave microstructure were harder than slowly-cooled samples with colony microstructure. Orientation-dependent deformation was found in the colony microstructure. Specifically, when the surface normal is perpendicular to the [0001] of alpha, the material deforms easily in the direction perpendicular to the [0001] of alpha. Fuzzy logic and Bayesian neural network models were developed to predict the room temperature tensile properties of Timetal 550. This involved the development of a database relating microstructural features to mechanical properties. A Gleeble 3800 thermal-mechanical simulator was used to develop various microstructures. Microstructural features of tensile-tested samples were quantified using stereological procedures. The quantified microstructural features and the tensile properties were used as inputs and outputs, respectively, for modeling the relationships between them. The individual influence of five microstructural features on tensile properties was determined using the established models. The microstructural features having the greatest impact on UTS and YS were the thickness of alpha laths and the width of grain boundary alpha layer, and the microstructural features having the greatest impact on elongation were the thickness of

Prediction of transport phenomena in near and far field: interaction solid phase/fluid phase

International Nuclear Information System (INIS)

Mingarro, E.

1995-01-01

The prediction of transport phenomena in near and far field is presented in the present report. The study begins with the analysis of solid phases stability: solubility of storage waste: UO 2 and solubility of radionuclides the redox and sorption-desorption conditions are the last aspects studied to predict the transport phenomena

Parietal EEG alpha suppression time of memory retrieval reflects memory load while the alpha power of memory maintenance is a composite of the visual process according to simultaneous and successive Sternberg memory tasks.

Science.gov (United States)

Okuhata, Shiho; Kusanagi, Takuya; Kobayashi, Tetsuo

2013-10-25

The present study investigated EEG alpha activity during visual Sternberg memory tasks using two different stimulus presentation modes to elucidate how the presentation mode affected parietal alpha activity. EEGs were recorded from 10 healthy adults during the Sternberg tasks in which memory items were presented simultaneously and successively. EEG power and suppression time (ST) in the alpha band (8-13Hz) were computed for the memory maintenance and retrieval phases. The alpha activity differed according to the presentation mode during the maintenance phase but not during the retrieval phase. Results indicated that parietal alpha power recorded during the maintenance phase did not reflect the memory load alone. In contrast, ST during the retrieval phase increased with the memory load for both presentation modes, indicating a serial memory scanning process, regardless of the presentation mode. These results indicate that there was a dynamic transition in the memory process from the maintenance phase, which was sensitive to external factors, toward the retrieval phase, during which the process converged on the sequential scanning process, the Sternberg task essentially required. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Alpha-1-antitrypsin augmentation therapy in deficient individuals enrolled in the Alpha-1 Foundation DNA and Tissue Bank

Directory of Open Access Journals (Sweden)

Adriano R Tonelli

2009-12-01

Full Text Available Adriano R Tonelli1, Farshid Rouhani1, Ning Li2, Pam Schreck1, Mark L Brantly11Alpha-1 Research Program, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, 2Department of Epidemiology and Biostatistics, University of Florida, Gainesville, Florida, USAIntroduction: Intravenous augmentation therapy with purified intravenous alpha-1 antitrypsin replaces the deficient protein and is the only currently approved treatment for alpha-1 antitrypsin deficiency (AATD related lung disease. While augmentation therapy has been available for more than 20 years, there are a limited number of studies evaluating the effect of augmentation on lung function.Material and methods: We examined the decline in forced expiratory volume in one second (FEV1 in patients enrolled in the Alpha-1 Foundation DNA and Tissue Bank in relation to the use or not of alpha-1 antitrypsin augmentation therapy. For the purpose of our analysis we included 164 patients with AATD and PI ZZ genotype.Results: Mean age of the patients was 60 years, 52% were females, 94% were white and 78% ex-smokers. The mean FEV1 at baseline was 1.7 L and the mean FEV1 % of predicted was 51.3%. The mean follow-up time was 41.7 months. A total of 124 (76% patients received augmentation therapy (augmented group while 40 patients (24% did not received it (non-augmented group. When adjusted by age at baseline, sex, smoking status, baseline FEV1 % of predicted, the mean overall change in FEV1 was 47.6 mL/year, favoring the augmented group (?FEV1 10.6 ± 21.4 mL/year in comparison with the non-augmented group (?FEV1 −36.96 ± 12.1 mL/year (P = 0.05. Beneficial ?FEV1 were observed in ex-smokers and the group with initial FEV1 % of predicted of <50%. No differences were observed in mortality.Conclusions: In conclusion, augmentation therapy improves lung function in subjects with AATD when adjusted by age, gender, smoking status and baseline FEV1 % of predicted. The beneficial

The effects of HIP processing on microstructure and phase relations in. alpha. sub 2 -base titanium aluminides

Energy Technology Data Exchange (ETDEWEB)

Saqib, M. (Dept. of Mechanical and Materials Engineering, Wright State Univ., Dayton, OH (United States)); Apgar, L.S.; Eylon, D. (Graduate Materials Engineering, Univ. of Dayton, OH (United States)); Weiss, I. (Dept. of Mechanical and Materials Engineering, Wright State Univ., Dayton, OH (United States))

1992-05-30

Cast {alpha}{sub 2}-base alloy (Ti-25Al-10Nb-3V-1Mo, at.%) underwent hot isostatic pressing (HIP) at temperatures ranging from 925 to 1125degC and pressures of 100-270 MPa. Effects of temperature and pressure during HIP, on microstructure and volume fraction of the phases present, were investigated. Microstructural characterization was carried out using optical microscopy and transmission electron microscopy. The phases present were identified using selected area and convergent beam electron diffraction. Volume fraction of the phases was determined using X-ray diffraction. Optimum refinement in the microstructure was obtained following HIP at 1020degC/262 MPa/6 h. The volume fraction of the B2 phase increased from 12% in the as-cast condition to 45% following HIP at 982degC/262 MPa/6 h. Experiments on forged Ti-25Al-10Nb-3V-1Mo alloy demonstrated that changes in volume fraction of the phases owing to HIP was applicable for cast as well as forged material. Sharp decrease in the volume fraction of the B2 phase was observed when as-HIP materials were aged at elevated temperature. Possible mechanisms of these changes in the phase stability and microstructure are discussed. (orig.).

Void fraction prediction in two-phase flows independent of the liquid phase density changes

International Nuclear Information System (INIS)

Nazemi, E.; Feghhi, S.A.H.; Roshani, G.H.

2014-01-01

Gamma-ray densitometry is a frequently used non-invasive method to determine void fraction in two-phase gas liquid pipe flows. Performance of flow meters using gamma-ray attenuation depends strongly on the fluid properties. Variations of the fluid properties such as density in situations where temperature and pressure fluctuate would cause significant errors in determination of the void fraction in two-phase flows. A conventional solution overcoming such an obstacle is periodical recalibration which is a difficult task. This paper presents a method based on dual modality densitometry using Artificial Neural Network (ANN), which offers the advantage of measuring the void fraction independent of the liquid phase changes. An experimental setup was implemented to generate the required input data for training the network. ANNs were trained on the registered counts of the transmission and scattering detectors in different liquid phase densities and void fractions. Void fractions were predicted by ANNs with mean relative error of less than 0.45% in density variations range of 0.735 up to 0.98 gcm −3 . Applying this method would improve the performance of two-phase flow meters and eliminates the necessity of periodical recalibration. - Highlights: • Void fraction was predicted independent of density changes. • Recorded counts of detectors/void fraction were used as inputs/output of ANN. • ANN eliminated necessity of recalibration in changeable density of two-phase flows

Theoretical study of titanium phases; Etude theorique des phases du titane

Energy Technology Data Exchange (ETDEWEB)

Trinite, V

2006-10-15

The aim of this work is to obtain a good understanding of the phase diagram of titanium within density functional theory. This diagram is composed of the alpha phase, the high pressure omega phase and the high temperature beta phase. This requires the differences in total energy to be predicted with a great precision, because these differences are around 50 meV. I find the omega phase to be the most stable one by ab initio calculation at zero temperature and pressure, in contradiction to the experimental results. I find this inversion of the stability also appears in titanium dioxide and zirconium. I have analyzed all the approximations brought into play in the ab initio approach. I have estimated the zero point energy and studied the impact of including the semi-core states as well as the effect of the exchange-correlation functionals. The conclusion is that the usual approximations for the exchange-correlation generate the biggest part of the error. A possible correction is to take into account the electronic self-interaction. I have apply this correction to the semi-core states and find a systematic improvement of the cell parameters, but no improvement on the phase stability. So I can conclude that a better description of the exchange interaction on the localized 3d states is needed. Although the standard functionals of exchange-correlation are not accurate enough to predict the phase diagrams of titanium, they perform well in describing physical properties less demanding in terms of precision, like elastic constants. However, I find important that the predicted equilibrium volume must be precise, as these properties are found strongly dependent on the volume. (author)

Critical linear thermal expansion in the smectic-A phase near the nematic-smectic phase transition.

Science.gov (United States)

Anesta, E; Iannacchione, G S; Garland, C W

2004-10-01

Recent high-resolution x-ray investigations of the smectic- A (SmA) phase near the nematic-to-SmA transition provide information about the critical behavior of the linear thermal expansion coefficient alpha// parallel to the director. Combining such data with available volume thermal expansion alpha(V) data yields the in-plane linear expansion coefficient alpha(perpendicular) . The critical behaviors of alpha// and alpha(perpendicular) are the same as those for alpha(V) and the heat capacity Cp. However, for any given liquid crystal, alpha//(crit) and alpha(perpendicular)(crit) differ in sign. Furthermore, the quantity alpha// (crit) is positive for SmAd partial bilayer smectics, while it is negative for nonpolar SmAm monomeric smectics. This feature is discussed in terms of the molecular structural aspects of these smectic phases.

Plutonium-238 alpha-decay damage study of the ceramic waste form

International Nuclear Information System (INIS)

Frank, S. M.; Barber, T. L.; Cummings, D.G.; DiSanto, T.; Esh, D.W.; Giglio, J. J.; Goff, K. M.; Johnson, S.G.; Kennedy, J.R.; Jue, J-F; Noy, M.; O'Holleran, T.P.; Sinkler, W.

2006-01-01

An accelerated alpha-decay damage study of a glass-bonded sodalite ceramic waste form has recently been completed. The purpose of this study was to investigate the physical and chemical durability of the waste form after significant exposure to alpha decay. This accelerated alpha-decay study was performed by doping the ceramic waste form with 238 Pu which has a much greater specific activity than 239 Pu that is normally present in the waste form. The alpha-decay dose at the end of the four year study was approximately 1 x 10 18 alpha-decays/gram of material. An equivalent time period for a similar dose of 239 Pu would require approximately 1100 years. After four years of exposure to 238 Pu alpha decay, the investigation observed little change to the physical or chemical durability of the ceramic waste form (CWF). Specifically, the 238 Pu-loaded CWF maintained it's physical integrity, namely that the density remained constant and no cracking or phase de-bonding was observed. The materials chemical durability and phase stability also did not change significantly over the duration of the study. The only significant measured change was an increase of the unit-cell lattice parameters of the plutonium oxide and sodalite phases of the material and an increase in the release of salt components and plutonium of the waste form during leaching tests, but, as mentioned, these did not lead to any overall loss of waste form durability. The principal findings from this study are: (1) 238 Pu-loaded CWF is similar in microstructure and phase composition to referenced waste form. (2) Pu was observed primarily as oxide comprised of aggregates of nano crystals with aggregates ranging in size from submicron to twenty microns in diameter. (3) Pu phases were primarily found in the intergranular glassy regions. (4) PuO phase shows expected unit cell volume expansion due to alpha decay damage of approximately 0.7%, and the sodalite phase unit cell volume has expanded slightly by 0.3% again

Anomalous atomic volume of alpha-Pu

DEFF Research Database (Denmark)

Kollar, J.; Vitos, Levente; Skriver, Hans Lomholt

1997-01-01

We have performed full charge-density calculations for the equilibrium atomic volumes of the alpha-phase light actinide metals using the local density approximation (LDA) and the generalized gradient approximation (GGA). The average deviation between the experimental and the GGA atomic radii is 1.......3%. The comparison between the LDA and GGA results show that the anomalously large atomic volume of alpha-Pu relative to alpha-Np can be ascribed to exchange-correlation effects connected with the presence of low coordinated sites in the structure where the f electrons are close to the onset of localization...

The analysis of predictability of recent alpha decay formulae and the alpha partial half-lives of some exotic nuclei

International Nuclear Information System (INIS)

Dasgupta-Schubert, N.; Reyes, M. A.; Tamez, V. A.

2009-01-01

Alpha decay is one of the two main decay modes of the heaviest nuclei, (SHE), and constitutes one of the dominant decay modes of highly neutron deficient medium mass nuclei ('exotics'). Thus identifying and characterizing the alpha decay chains form a crucial part of the identification of SHE. We report the extension of the previously developed method for the detailed and systematic investigation of the reliability of the three main extant analytical formulae of alpha decay half-lives: the generalized liquid drop model based formula of Royer et al. (FR), the Sobiczewski modified semi-empirical Viola-Seaborg formula (VSS) and the recent phenomenological formula of Sobiczewski and Parkhomenko (SP).

[Alpha-melanocyte-stimulating hormone. From bench to bedside].

Science.gov (United States)

Böhm, M; Luger, T A

2010-06-01

Alpha-melanocyte-stimulating hormone (alpha-MSH) is a tridecapeptide that is produced by the skin itself from the precursor proopiomelanocortin. It crucially mediates ultraviolet light-induced tanning after binding to melanocortin-1 receptors (MC-1R) expressed on the surface of epidermal melanocytes. The potent pigment-inducing and also cytoprotective actions of alpha-MSH are the rationale for the performance of first phase II clinical trials with Nle4-D-Phe7-alpha-MSH (NDP-alpha-MSH), a subcutaneously administered synthetic and superpotent alpha-MSH analogue, in patients with photodermatoses such as erythropoietic protoporphyria. Since alpha-MSH has shown promising anti-inflammatory and antifibrotic properties in numerous preclinical studies, it will be most interesting to evaluate these effects in further clinical pilot studies with NDP-alpha-MSH. In addition to alpha-MSH analogues, truncated tripeptides such as KDPT which do not bind to MC-1R but have sustained anti-inflammatory properties are currently emerging as another novel therapeutic strategy in dermatology.

ALPHA-CTX is associated with subchondral bone turnover and predicts progression of joint space narrowing and osteophytes in osteoarthritis

Science.gov (United States)

Huebner, Janet L; Bay-Jensen, Anne C; Huffman, Kim M; He, Yi; Leeming, Diana J; McDaniel, Gary E; Karsdal, Morten A; Kraus, Virginia B

2014-01-01

Objective To evaluate joint tissue remodeling, with urinary collagen biomarkers, uALPHA CTX and uCTXII, and their association with osteoarthritis (OA) severity, progression, and localized knee bone turnover. Methods Participants (N=149) with symptomatic and radiographic knee OA underwent fixed flexion knee radiography at baseline and 3 years, and late-phase bone scintigraphy of both knees at baseline, scored semi-quantitatively for osteophyte (OST) and joint space narrowing (JSN) severity and uptake intensity with scores summed across knees. Urinary concentrations of ALPHA CTX and CTXII were determined by ELISA. Immunohistochemistry of human OA knees was performed to localize the joint tissue origin of the biomarker epitopes. Results uALPHA CTX correlated strongly with intensity of bone scintigraphic uptake, and JSN and OST progression (risk ratio=13.2 and 3, respectively). uCTXII was strongly associated with intensity of bone scintigraphic uptake, with JSN and OST severity, and OA progression based on OST. uALPHA CTX localized primarily to high bone turnover areas in subchondral bone; CTXII localized to the bone-cartilage interface, the tidemark, and damaged articular cartilage. Conclusion Baseline uALPHA CTX, localized to high turnover areas of subchondral bone, was associated with dynamic bone turnover of knees signified by scintigraphy, and progression of both OST and JSN. uCTXII correlated with JSN and OST severity, and progression of OST. To our knowledge, this represents the first report of serological markers reflecting subchondral bone turnover. These collagen markers may be useful for non-invasive detection and quantification of active subchondral bone turnover and joint remodeling in knee OA. PMID:24909851

A contribution to the structural and kinetic study of the slow transformation of an iron or uranium alpha crystal; Contribution a l'etude structurale et cinetique de la transformation lente d'un cristal de fer alpha ou d'uranium alpha

Energy Technology Data Exchange (ETDEWEB)

Donze, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-12-15

1- During the course of the work reported, we observed and studied a curious phenomenon of regeneration of an iron or uranium {alpha} crystal in the double transformation of iron or uranium: {alpha} {yields} {gamma} {yields} {alpha} and {alpha} {yields} {beta} {yields} {alpha} respectively. We have demonstrated that this phenomenon does not occur with very pure metals, but only in the case of metals containing impurities, and more particularly, containing carbon. The monocrystal is not regenerated unless care is taken not to exceed final transformation temperatures by more than a few degrees. The same phenomenon is encountered in polycrystalline compounds: the orientation of the crystals is maintained, though the respective grain positions ('joints') are considerably displaced. 2- Kinetic study of the transformation at cooling, on the one hand, and the analysis of the texture at the {gamma} phase (iron) on the other, show that regeneration results from the conservation of the phase {alpha} germs at the high temperature phase. They appear to be relatively stable because they had retained their properties at the end of 24 hours at the experiment temperature. 3- Study of the twin crystals of {gamma} iron engendered by the transformation {alpha} {yields} {gamma} demonstrated that there is no orientation relationship in the transformation: {alpha} {yields} {gamma} of pure iron. 4- Thanks to the production of an epitaxic oxide film on the surface of {gamma} iron, we were able to evidence a new type of iron transformation twinned crystal which grows in one direction (110) and is in contact also at 110. Formed of very thin lamina, these crystals are very instable and become penetrant, each element - much larger - consisting of the increased thickness of a certain number of lamina. (author) [French] 1- Au cours de ce travail, nous avons observe et etudie un curieux phenomene de regeneration d'un cristal unique de fer {alpha} ou d'uranium {alpha} au cours de la double

Determination of alpha-Tocopherol (vitamin E) in irradiated garlic by high performance liquid chromatography (HPLC); Determinacao de alpha-tocoferol em alho irradiado utilizando cromatografia liquida de alta frequencia (CLAE)

Energy Technology Data Exchange (ETDEWEB)

Rios, Magda Dias Goncalves; Penteado, Marilene de Vuono Camargo [Sao Paulo Univ., SP (Brazil). Faculdade de Ciencias Farmaceuticas. Dept. de Alimentos e Nutricao Experimental]. E-mail: riosmagda@hotmail.com

2003-02-01

The effects of {sup 60}Co ionizing radiations in doses of 0, 75, 100, 150, 200 and 250Gy on garlic, upon the {alpha}-tocopherol concentration were studied. The {alpha}-tocopherol contents were established by high performance liquid chromatography (HPLC), after direct hexane extraction from the garlic samples. The {alpha}-tocopherol was determined through normal phase column, and mobile phase was composed by hexane: iso-propyl alcohol (99:01 v/v), with 2mL/min flow rate and fluorescence detector. It is statistically shown that an irradiation dose of up to 150 Gy does not affect the garlic {alpha}-tocopherol content. (author)

Temozolomide and interferon-alpha in metastatic melanoma: a phase II study of the Italian Melanoma Intergroup.

Science.gov (United States)

Ridolfi, Ruggero; Romanini, Antonella; Sileni, Vanna Chiarion; Michiara, Maria; Guida, Michele; Biasco, Guido; Poletti, Paola; Amaducci, Laura; Leoni, Maurizio; Ravaioli, Alessandra

2004-08-01

Temozolomide (TMZ) is a new oral alkylating agent which has proven to be as active as dacarbazine (DTIC) in the treatment of melanoma, but with a lower toxicity. A multicentric phase II trial was conducted in an out-patient setting to determine the therapeutic activity and safety of TMZ in combination with interferon-alpha (IFN-alpha). From June 2000 to July 2001, 41 patients were recruited to receive TMZ 200 mg/m orally on days 1-5 every 28 days and with 5 MU IFN-alpha subcutaneously three times a week, continuously for eight cycles or until disease progression occurred. Of the 40 treated patients, two complete responses (5%) and three partial responses (7.5%) were observed, with a median duration of 4 months (range, 1.5-13.5 months). Thirteen patients (32.5%) had stable disease for a median of 2.5 months. Time to progression was 2.6 months and the median overall survival was 11.8 months. Nine patients (22.5%) developed brain metastases. The grade 4 toxicity observed in seven patients was of a transient haematological nature. This combination therapy is well tolerated but does not appear to increase the response rate or overall survival with respect to TMZ alone or to chemotherapeutic regimens. Further and more complex associations of these two drugs could be investigated in specific subsets of patients, in particular to evaluate its real efficacy in preventing brain metastases. Copyright 2004 Lippincott Williams & Wilkins

Seven-Disk Manifold, alpha-attractors and B-modes

CERN Document Server

Ferrara, Sergio

2016-01-01

Cosmological alpha-attractor models in \\cN=1 supergravity are based on hyperbolic geometry of a Poincar\\'e disk with the radius square {\\cal R}^2=3\\alpha. The predictions for the B-modes, r\\approx 3\\alpha {4\\over N^2}, depend on moduli space geometry and are robust for a rather general class of potentials. Here we notice that starting with M-theory compactified on a 7-manifold with G_2 holonomy, with a special choice of Betti numbers, one can obtain d=4 \\cN=1 supergravity with rank 7 scalar coset \\Big[{SL(2)\\over SO(2)}\\Big]^7. In a model where these 7 unit size Poincar\\'e disks have identified moduli one finds that 3 alpha =7. Assuming that the moduli space geometry of the phenomenological models is inherited from this version of M-theory, one would predict r \\approx 10^{-2} for 53 e-foldings. We also describe the related maximal supergravity and M/string theory models leading to preferred values 3 alpha =1,2,3,4,5,6,7.

Alpha-deuteron elastic scattering around 40 MeV

International Nuclear Information System (INIS)

De, A.; Karmakar, S.; Roychaudhury, T.; Dasgupta, S.S.; Chintalapudi, S.N.; Ismail, M.; Banerjee, S.R.; Divatia, A.S.

1989-01-01

Differential cross section for alpha-deuteron elastic scattering has been measured at several energies around 40 MeV incident alpha. General behaviour of angular distributions remaining close to that predicted by Faddeev type calculations, a sharp energy dependence is observed. (author). 8 refs

Learning temporal context shapes prestimulus alpha oscillations and improves visual discrimination performance.

Science.gov (United States)

Toosi, Tahereh; K Tousi, Ehsan; Esteky, Hossein

2017-08-01

Time is an inseparable component of every physical event that we perceive, yet it is not clear how the brain processes time or how the neuronal representation of time affects our perception of events. Here we asked subjects to perform a visual discrimination task while we changed the temporal context in which the stimuli were presented. We collected electroencephalography (EEG) signals in two temporal contexts. In predictable blocks stimuli were presented after a constant delay relative to a visual cue, and in unpredictable blocks stimuli were presented after variable delays relative to the visual cue. Four subsecond delays of 83, 150, 400, and 800 ms were used in the predictable and unpredictable blocks. We observed that predictability modulated the power of prestimulus alpha oscillations in the parieto-occipital sites: alpha power increased in the 300-ms window before stimulus onset in the predictable blocks compared with the unpredictable blocks. This modulation only occurred in the longest delay period, 800 ms, in which predictability also improved the behavioral performance of the subjects. Moreover, learning the temporal context shaped the prestimulus alpha power: modulation of prestimulus alpha power grew during the predictable block and correlated with performance enhancement. These results suggest that the brain is able to learn the subsecond temporal context of stimuli and use this to enhance sensory processing. Furthermore, the neural correlate of this temporal prediction is reflected in the alpha oscillations. NEW & NOTEWORTHY It is not well understood how the uncertainty in the timing of an external event affects its processing, particularly at subsecond scales. Here we demonstrate how a predictable timing scheme improves visual processing. We found that learning the predictable scheme gradually shaped the prestimulus alpha power. These findings indicate that the human brain is able to extract implicit subsecond patterns in the temporal context of

Functional Cortical Network in Alpha Band Correlates with Social Bargaining

Science.gov (United States)

Billeke, Pablo; Zamorano, Francisco; Chavez, Mario; Cosmelli, Diego; Aboitiz, Francisco

2014-01-01

Solving demanding tasks requires fast and flexible coordination among different brain areas. Everyday examples of this are the social dilemmas in which goals tend to clash, requiring one to weigh alternative courses of action in limited time. In spite of this fact, there are few studies that directly address the dynamics of flexible brain network integration during social interaction. To study the preceding, we carried out EEG recordings while subjects played a repeated version of the Ultimatum Game in both human (social) and computer (non-social) conditions. We found phase synchrony (inter-site-phase-clustering) modulation in alpha band that was specific to the human condition and independent of power modulation. The strength and patterns of the inter-site-phase-clustering of the cortical networks were also modulated, and these modulations were mainly in frontal and parietal regions. Moreover, changes in the individuals’ alpha network structure correlated with the risk of the offers made only in social conditions. This correlation was independent of changes in power and inter-site-phase-clustering strength. Our results indicate that, when subjects believe they are participating in a social interaction, a specific modulation of functional cortical networks in alpha band takes place, suggesting that phase synchrony of alpha oscillations could serve as a mechanism by which different brain areas flexibly interact in order to adapt ongoing behavior in socially demanding contexts. PMID:25286240

Alpha particle analysis using PEARLS spectrometry

International Nuclear Information System (INIS)

McKlveen, J.W.; Klingler, G.W.; McDowell, W.J.; Case, G.N.

1984-01-01

Alpha particle assay by conventional plate-counting methods is difficult because chemical separation, tracer techniques, and/or self-absorption losses in the final sample may cause either non-reproducible results or create unacceptable errors. PEARLS (Photon-Electron Rejecting Alpha Liquid Scintillation) Spectrometry is an attractive alternative since radionuclides may be extracted into a scintillator in which there would be no self-absorption or geometry problems and in which up to 100% chemical recovery and counting efficiency is possible. Sample preparation may include extraction of the alpha emitter of interest by a specific organic-phase-soluble compound directly into the liquid scintillator. Detection electronics use energy and pulse-shape discrimination to provide discrete alpha spectra and virtual absence of beta and gamma backgrounds. Backgrounds on the order of 0.01 cpm are readily achievable. Accuracy and reproducibility are typically in the 100 +-1% range. Specific procedures have been developed for gross alpha, uranium, plutonium, thorium, and polonium assay. This paper will review liquid scintillation alpha counting methods and reference some of the specific applications. 8 refs., 1 fig

Synthesis of peptide .alpha.-thioesters

Science.gov (United States)

Camarero, Julio A [Livermore, CA; Mitchell, Alexander R [Livermore, CA; De Yoreo, James J [Clayton, CA

2008-08-19

Disclosed herein is a new method for the solid phase peptide synthesis (SPPS) of C-terminal peptide .alpha. thioesters using Fmoc/t-Bu chemistry. This method is based on the use of an aryl hydrazine linker, which is totally stable to conditions required for Fmoc-SPPS. When the peptide synthesis has been completed, activation of the linker is achieved by mild oxidation. The oxidation step converts the acyl-hydrazine group into a highly reactive acyl-diazene intermediate which reacts with an .alpha.-amino acid alkylthioester (H-AA-SR) to yield the corresponding peptide .alpha.-thioester in good yield. A variety of peptide thioesters, cyclic peptides and a fully functional Src homology 3 (SH3) protein domain have been successfully prepared.

Thermal property prediction and measurement of organic phase change materials in the liquid phase near the melting point

International Nuclear Information System (INIS)

O’Connor, William E.; Warzoha, Ronald; Weigand, Rebecca; Fleischer, Amy S.; Wemhoff, Aaron P.

2014-01-01

Highlights: • Liquid-phase thermal properties for five phase change materials were estimated. • Various liquid phase and phase transition thermal properties were measured. • The thermal diffusivity was found using a best path to prediction approach. • The thermal diffusivity predictive method shows 15% agreement for organic PCMs. - Abstract: Organic phase change materials (PCMs) are a popular choice for many thermal energy storage applications including solar energy, building envelope thermal barriers, and passive cooling of portable electronics. Since the extent of phase change during a heating or cooling process is dependent upon rapid thermal penetration into the PCM, accurate knowledge of the thermal diffusivity of the PCM in both solid and liquid phases is crucial. This study addresses the existing gaps in information for liquid-phase PCM properties by examining an approach that determines the best path to prediction (BPP) for the thermal diffusivity of both alkanes and unsaturated acids. Knowledge of the BPP will enable researchers to explore the influence of PCM molecular structure on bulk thermophysical properties, thereby allowing the fabrication of optimized PCMs. The BPP method determines which of the tens of thousands of combinations of 22 different available theoretical techniques provides best agreement with thermal diffusivity values based on reported or measured density, heat capacity, and thermal conductivity for each of five PCMs (heneicosane, tricosane, tetracosane, oleic acid, and linoleic acid) in the liquid phase near the melting point. Separate BPPs were calibrated for alkanes based on heneicosane and tetracosane, and for the unsaturated acids. The alkane and unsaturated acid BPPs were then tested on a variety of similar materials, showing agreement with reported/measured thermal diffusivity within ∼15% for all materials. The alkane BPP was then applied to find that increasing the length of alkane chains decreases the PCM thermal

Predicting phase equilibria in one-component systems

Science.gov (United States)

Korchuganova, M. R.; Esina, Z. N.

2015-07-01

It is shown that Simon equation coefficients for n-alkanes and n-alcohols can be modeled using critical and triple point parameters. Predictions of the phase liquid-vapor, solid-vapor, and liquid-solid equilibria in one-component systems are based on the Clausius-Clapeyron relation, Van der Waals and Simon equations, and the principle of thermodynamic similarity.

Numerical predictions of particle dispersed two-phase flows, using the LSD and SSF models

International Nuclear Information System (INIS)

Avila, R.; Cervantes de Gortari, J.; Universidad Nacional Autonoma de Mexico, Mexico City. Facultad de Ingenieria)

1988-01-01

A modified version of a numerical scheme which is suitable to predict parabolic dispersed two-phase flow, is presented. The original version of this scheme was used to predict the test cases discussed during the 3rd workshop on TPF predictions in Belgrade, 1986. In this paper, two particle dispersion models are included which use the Lagrangian approach predicting test case 1 and 3 of the 4th workshop. For the prediction of test case 1 the Lagrangian Stochastic Deterministic model (LSD) is used providing acceptable good results of mean and turbulent quantities for both solid and gas phases; however, the computed void fraction distribution is not in agreement with the measurements at locations away from the inlet, especially near the walls. Test case 3 is predicted using both the LSD and the Stochastic Separated Flow (SSF) models. It was found that the effects of turbulence modulation are large when the LSD model is used, whereas the particles have a negligible influence on the continuous phase if the SSF model is utilized for the computations. Predictions of gas phase properties based on both models agree well with measurements; however, the agreement between calculated and measured solid phase properties is less satisfactory. (orig.)

Prediction of the phase equilibria of methane hydrates using the direct phase coexistence methodology

Energy Technology Data Exchange (ETDEWEB)

Michalis, Vasileios K.; Costandy, Joseph; Economou, Ioannis G., E-mail: ioannis.economou@qatar.tamu.edu [Chemical Engineering Program, Texas A and M University at Qatar, P.O. Box 23847, Doha (Qatar); Tsimpanogiannis, Ioannis N.; Stubos, Athanassios K. [Environmental Research Laboratory, National Center for Scientific Research NCSR “Demokritos,” Aghia Paraskevi, Attiki GR-15310 (Greece)

2015-01-28

The direct phase coexistence method is used for the determination of the three-phase coexistence line of sI methane hydrates. Molecular dynamics (MD) simulations are carried out in the isothermal–isobaric ensemble in order to determine the coexistence temperature (T{sub 3}) at four different pressures, namely, 40, 100, 400, and 600 bar. Methane bubble formation that results in supersaturation of water with methane is generally avoided. The observed stochasticity of the hydrate growth and dissociation processes, which can be misleading in the determination of T{sub 3}, is treated with long simulations in the range of 1000–4000 ns and a relatively large number of independent runs. Statistical averaging of 25 runs per pressure results in T{sub 3} predictions that are found to deviate systematically by approximately 3.5 K from the experimental values. This is in good agreement with the deviation of 3.15 K between the prediction of TIP4P/Ice water force field used and the experimental melting temperature of ice Ih. The current results offer the most consistent and accurate predictions from MD simulation for the determination of T{sub 3} of methane hydrates. Methane solubility values are also calculated at the predicted equilibrium conditions and are found in good agreement with continuum-scale models.

Prediction for the high-level alpha-active waste to be generated by nuclear power stations in the Member States of the European Communities

International Nuclear Information System (INIS)

Schmidt, E.

1977-04-01

Starting with a forecast for the nuclear power generating capacity to be installed in the Member States of the European Communities before the end of this century, a prediction is made of the annual production of high-level alpha-active waste from reprocessing plants and the corresponding accumulation up to the year 2000. The isotopic composition of the alpha-active waste from individual reactor types was calculated and an estimation of the influence of recycling plutonium through light water reactors on the produced quantity of higher actinides is made

Radial-velocity variations in Alpha Ori, Alpha Sco, and Alpha Her

International Nuclear Information System (INIS)

Smith, M.A.; Patten, B.M.; Goldberg, L.

1989-01-01

Radial-velocity observations of Alpha Ori, Alpha Sco A, and Alpha Her A are used to study radial-velocity periodicities in M supergiants. The data refer to several metallic lines in the H-alpha region and to H-alpha itself. It is shown that Alpha Ori and Alpha Sco A have cycle lengths of about 1 yr and semiamplitudes of 2 km/s. It is suggested that many semiregular red supergiant varibles such as Alpha Ori may be heading toward chaos. All three stars show short-term stochastic flucutations with an amplitude of 1-2 km/s. It is found that the long-term variability of H-alpha velocities may be a consequence of intermittent failed ejections. 58 refs

Two-stage gas-phase bioreactor for the combined removal of hydrogen sulphide, methanol and alpha-pinene.

Science.gov (United States)

Rene, Eldon R; Jin, Yaomin; Veiga, María C; Kennes, Christian

2009-11-01

Biological treatment systems have emerged as cost-effective and eco-friendly techniques for treating waste gases from process industries at moderately high gas flow rates and low pollutant concentrations. In this study, we have assessed the performance of a two-stage bioreactor, namely a biotrickling filter packed with pall rings (BTF, 1st stage) and a perlite + pall ring mixed biofilter (BF, 2nd stage) operated in series, for handling a complex mixture of hydrogen sulphide (H2S), methanol (CH3OH) and alpha-pinene (C10H16). It has been reported that the presence of H2S can reduce the biofiltration efficiency of volatile organic compounds (VOCs) when both are present in the gas mixture. Hydrogen sulphide and methanol were removed in the first stage BTF, previously inoculated with H2S-adapted populations and a culture containing Candida boidinii, an acid-tolerant yeast, whereas, in the second stage, alpha-pinene was removed predominantly by the fungus Ophiostoma stenoceras. Experiments were conducted in five different phases, corresponding to inlet loading rates varying between 2.1 and 93.5 g m(-3) h(-1) for H2S, 55.3 and 1260.2 g m(-3) h(-1) for methanol, and 2.8 and 161.1 g m(-3) h(-1) for alpha-pinene. Empty bed residence times were varied between 83.4 and 10 s in the first stage and 146.4 and 17.6 s in the second stage. The BTF, working at a pH as low as 2.7 as a result of H2S degradation, removed most of the H2S and methanol but only very little alpha-pinene. On the other hand, the BF, at a pH around 6.0, removed the rest of the H2S, the non-degraded methanol and most of the alpha-pinene vapours. Attempts were originally made to remove the three pollutants in a single acidophilic bioreactor, but the Ophiostoma strain was hardly active at pH elimination capacities (ECs) reached by the two-stage bioreactor for individual pollutants were 894.4 g m(-3) h(-1) for methanol, 45.1 g m(-3) h(-1) for H2S and 138.1 g m(-3) h(-1) for alpha-pinene. The results from this

Chemical reactivity of {alpha}-isosaccharinic acid in heterogeneous alkaline systems

Energy Technology Data Exchange (ETDEWEB)

Glaus, M. A.; Loon, L. R. Van

2009-05-15

Cellulose degradation under alkaline conditions is of relevance for the mobility of many radionuclides in the near-field of a cementitious repository for radioactive waste, because metal-binding degradation products may be formed. Among these, {alpha}- isosaccharinic acid ({alpha}-ISA) is the strongest complexant. The prediction of the equilibrium concentration of {alpha}-ISA in cement pore water is therefore an important step in the assessment of the influence of cellulose degradation products on the speciation of radionuclides in such environments. The present report focuses on possible chemical transformation reactions of {alpha}-ISA in heterogeneous alkaline model systems containing either Ca(OH){sub 2} or crushed hardened cement paste. The transformation reactions were monitored by measuring the concentration of {alpha}-ISA by high performance anion exchange chromatography and the formation of reaction products by high performance ion exclusion chromatography. The overall loss of organic species from solution was monitored by measuring the concentration of non-purgeable organic carbon. The reactions were examined in diluted and compacted suspensions, at either 25 {sup o}C or 90 {sup o}C, and under anaerobic atmospheres obtained by various methods. It was found that {alpha}-ISA was transformed under all conditions tested to some extent. Reaction products, such as glycolate, formate, lactate and acetate, all compounds with less complexing strength than {alpha}-ISA, were detected. The amount of reaction products identified by the chromatographic technique applied was {approx} 50 % of the amount of {alpha}-ISA reacted. Sorption of {alpha}-ISA to Ca(OH){sub 2} contributed only to a minor extent to the loss of {alpha}-ISA from the solution phase. As the most important conclusion of the present work it was demonstrated that the presence of oxidising agents had a distinctive influence on the turnover of {alpha}-ISA. Under aerobic conditions {alpha}-ISA was

Role of alpha2C-adrenoceptor subtype in spatial working memory as revealed by mice with targeted disruption of the alpha2C-adrenoceptor gene.

Science.gov (United States)

Tanila, H; Mustonen, K; Sallinen, J; Scheinin, M; Riekkinen, P

1999-02-01

The role of the alpha2C-adrenoceptor subtype in mediating the beneficial effect of alpha2-adrenoceptor agonists on spatial working memory was studied in adult mice with targeted inactivation of the alpha2C-receptor gene (KO) and their wild-type controls (WT). A delayed alternation task was run in a T-maze with mixed delays varying from 20 s to 120 s. Dexmedetomidine, a specific but subtype nonselective alpha2-adrenoceptor agonist, dose-dependently decreased the total number of errors. The effect was strongest at the dose of 5 microg/kg (s.c.), and was observed similarly in KO and WT mice. KO mice performed inferior to WT mice due to a higher number of perseverative errors. Dexmedetomidine slowed initiation of the motor response in the start phase at lower doses in WT mice than in KO mice but no such difference was observed in the return phase of the task, suggesting involvement of alpha2C-adrenoceptors in the cognitive aspect of response preparation or in response sequence initiation. According to these findings, enhancement of spatial working memory is best achieved with alpha2-adrenoceptor agonists which have neither agonistic nor antagonistic effects at the alpha2C-adrenoceptor subtype.

Contribution to the study of the sintering mechanisms of uranium powders in the {alpha}, {beta}, and {gamma} phases; Contribution a l'etude des mecanismes de frittage de poudre d'uranium en phases {alpha}, {beta}, et {gamma}

Energy Technology Data Exchange (ETDEWEB)

Pinteau, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-06-01

This study of the sintering mechanisms of uranium powders prepared by calci-thermy has been effected using continuous dilatometric measurements of the shrinkage of samples previously compressed at room temperature in purified argon gas. The tests carried out in the {alpha}, {beta} and {gamma} phases have led to the observation that the first step of the sintering appears to be governed by a volume self-diffusion mechanism; the activation heat values found for the sintering mechanisms are close to those deduced during studies of volume self-diffusion using the direct radio-tracer method. Furthermore it has been possible to show that in the {gamma} domain a second sintering mechanism occurs involving much longer sintering times; the heats of activation are much lower and this appears to indicate that there occurs a mechanism involving pore elimination by grain boundary diffusion of the vacancies. Furthermore, the dilatometric tests have shown the simultaneous influence of two important parameters in this work: grain boundaries and the diffusion coefficients. In the second part of the report are given results concerning the examination of sintered samples by various methods with a view to elucidating their structure and some of their physical properties. In this way it has been possible, by carrying out metallographic examinations after etching by ionic bombardment, to determine the changes in the porosity of the three phases {alpha}, {beta} and {gamma}, as well as the structure and the nature of the inclusions in each sample. Density and porosity measurements have also been carried out. The variations in these two sets of results make it possible to confirm the preceding dilatometric end micro-graphic examinations. Finally a detailed dilatometric study of the samples sintered in the {gamma} phase has shown the effect of oxide layers, associated with the existence of porosity, on the amplitudes and temperatures of the allotropic transformations, these latter being

High-pressure phase transitions - Examples of classical predictability

Science.gov (United States)

Celebonovic, Vladan

1992-09-01

The applicability of the Savic and Kasanin (1962-1967) classical theory of dense matter to laboratory experiments requiring estimates of high-pressure phase transitions was examined by determining phase transition pressures for a set of 19 chemical substances (including elements, hydrocarbons, metal oxides, and salts) for which experimental data were available. A comparison between experimental and transition points and those predicted by the Savic-Kasanin theory showed that the theory can be used for estimating values of transition pressures. The results also support conclusions obtained in previous astronomical applications of the Savic-Kasanin theory.

Alpha-gamma phase amplitude coupling subserves information transfer during perceptual sequence learning.

Science.gov (United States)

Tzvi, Elinor; Bauhaus, Leon J; Kessler, Till U; Liebrand, Matthias; Wöstmann, Malte; Krämer, Ulrike M

2018-03-01

Cross-frequency coupling is suggested to serve transfer of information between wide-spread neuronal assemblies and has been shown to underlie many cognitive functions including learning and memory. In previous work, we found that alpha (8-13 Hz) - gamma (30-48 Hz) phase amplitude coupling (αγPAC) is decreased during sequence learning in bilateral frontal cortex and right parietal cortex. We interpreted this to reflect decreased demands for visuo-motor mapping once the sequence has been encoded. In the present study, we put this hypothesis to the test by adding a "simple" condition to the standard serial reaction time task (SRTT) with minimal needs for visuo-motor mapping. The standard SRTT in our paradigm entailed a perceptual sequence allowing for implicit learning of a sequence of colors with randomly assigned motor responses. Sequence learning in this case was thus not associated with reduced demands for visuo-motor mapping. Analysis of oscillatory power revealed a learning-related alpha decrease pointing to a stronger recruitment of occipito-parietal areas when encoding the perceptual sequence. Replicating our previous findings but in contrast to our hypothesis, αγPAC was decreased in sequence compared to random trials over right frontal and parietal cortex. It also tended to be smaller compared to trials requiring a simple motor sequence. We additionally analyzed αγPAC in resting-state data of a separate cohort. PAC in electrodes over right parietal cortex was significantly stronger compared to sequence trials and tended to be higher compared to simple and random trials of the SRTT data. We suggest that αγPAC in right parietal cortex reflects a "default-mode" brain state, which gets perturbed to allow for encoding of visual regularities into memory. Copyright © 2018 Elsevier Inc. All rights reserved.

Occurence and prediction of sigma phase in fuel cladding alloys for breeder reactors

International Nuclear Information System (INIS)

Anantatmula, R.P.

1982-01-01

In sodium-cooled fast reactor systems, fuel cladding materials will be exposed for several thousand hours to liquid sodium. Satisfactory performance of the materials depends in part on the sodium compatibility and phase stability of the materials. This paper mainly deals with the phase stability aspect, with particular emphasis on sigma phase formation of the cladding materials upon extended exposures to liquid sodium. A new method of predicting sigma phase formation is proposed for austenitic stainless steels and predictions are compared with the experimental results on fuel cladding materials. Excellent agreement is obtained between theory and experiment. The new method is different from the empirical methods suggested for superalloys and does not suffer from the same drawbacks. The present method uses the Fe-Cr-Ni ternary phase diagram for predicting the sigma-forming tendencies and exhibits a wide range of applicability to austenitic stainless steels and heat-resistant Fe-Cr-Ni alloys

Studies on the phase diagram of boron employing a neural network potential

Energy Technology Data Exchange (ETDEWEB)

Morawietz, Tobias; Behler, Joerg [Lehrstuhl fuer Theoretische Chemie, Ruhr-Universitaet Bochum (Germany); Parrinello, Michele [Department of Chemistry and Applied Biosciences, ETH Zuerich (Switzerland)

2009-07-01

The crystalline phases of elemental boron have a structural complexity unique in the periodic table. The complex connection pattern of the icosahedral building blocks forms a formidable challenge for the construction of accurate but efficient potentials. We present a high-dimensional neural network potential for boron, which is based on first-principles calculations and can be systematically improved. The potential is several orders of magnitude faster to evaluate than the underlying density-functional theory calculations and allows to perform long molecular dynamics and metadynamics simulations of large system. By a stepwise refinement of the potential and an application of the potential in metadynamics simulations we show that starting from random atomic positions the structure of {alpha}-boron is predicted in agreement with experiment. Further, pressure-induced phase transitions of {alpha}-boron are discussed.

Predicting Catastrophic Phase Inversion on the Basis of Droplet Coalescence Kinetics

NARCIS (Netherlands)

Vaessen, G.E.J.; Visschers, M.; Stein, H.N.

1996-01-01

A predictive model for catastrophic phase inversion, based on the kinetics of droplet breakup and coalescence, is presented here. Two inversion mechanisms can be distinguished, depending on the direction of the phase inversion process. With the surfactant predominantly present in the dispersed

A new method in prediction of TCP phases formation in superalloys

International Nuclear Information System (INIS)

Mousavi Anijdan, S.H.; Bahrami, A.

2005-01-01

The purpose of this investigation is to develop a model for prediction of topologically closed-packed (TCP) phases formation in superalloys. In this study, artificial neural networks (ANN), using several different network architectures, were used to investigate the complex relationships between TCP phases and chemical composition of superalloys. In order to develop an optimum ANN structure, more than 200 experimental data were used to train and test the neural network. The results of this investigation shows that a multilayer perceptron (MLP) form of the neural networks with one hidden layer and 10 nodes in the hidden layer has the lowest mean absolute error (MAE) and can be accurately used to predict the electron-hole number (N v ) and TCP phases formation in superalloys

High Quality Model Predictive Control for Single Phase Grid Connected Photovoltaic Inverters

DEFF Research Database (Denmark)

Zangeneh Bighash, Esmaeil; Sadeghzadeh, Seyed Mohammad; Ebrahimzadeh, Esmaeil

2018-01-01

Single phase grid-connected inverters with LCL filter are widely used to connect the photovoltaic systems to the utility grid. Among the presented control schemes, predictive control methods are faster and more accurate but are more complex to implement. Recently, the model-predictive control...... algorithm for single-phase inverter has been presented, where the algorithm implementation is straightforward. In the proposed approach, all switching states are tested in each switching period to achieve the control objectives. However, since the number of the switching states in single-phase inverter...... is low, the inverter output current has a high total harmonic distortions. In order to reduce the total harmonic distortions of the injected current, this paper presents a high-quality model-predictive control for one of the newest structure of the grid connected photovoltaic inverter, i.e., HERIC...

Alpha spectrometry of environmental and food samples with photon/electron-rejecting alpha liquid-scintillation (P.E.R.A.L.S.)

International Nuclear Information System (INIS)

Zehringer, M.; Stockli, M.

2006-01-01

Full text: In environmental and food monitoring radio-nuclides are normally analysed with gamma spectrometry. Routine analysis of cesium nuclides can be realised fast and without much sample preparation. Also a few nuclides of the uranium- and thorium-series can be detected with gamma spectrometry at the low Bq/kg level. 226 Ra, 224 Ra and 228 Ra can be determined via their decay products when secular equilibrium of the sample is reached (e.g. 226 Ra via its daughters 214 Pb and 214 Bi). Alpha spectrometry is the method of choice for the determination of alpha nuclides in the mBq range. The analytes have to be separated from interfering nuclides and quenching parameters prior to the spectrometry. So, the main ask in alpha spectrometry consists in an efficient sample preparation and an alpha/beta discrimination for the spectrometric measurement. Based on the work of Jack McDowell sensitive methods for the analyses of naturally occurring nuclides such as uranium, thorium, polonium and other alpha-nuclides in water, honey and spices were developed and validated [1]. Such techniques enables the tolerance and limit values for radionuclides in food to be controlled in accordance with of the Swiss Ordinance on contaminants and Ingredients (FIV) [2] he method principle is based on a selective extraction of the alpha nuclides rom water samples rsp. from an aqueous extract of mineralized samples. The extractant has also the function of a cocktail in the alpha liquid spectrometry nd therefore the extract can be analysed directly without further clean -up Photon/Electron-Rejecting Alpha-Liquid-Scintillation, P.E.R.A.L..S. [1]). Normally, one liter of water sample is extracted with 5 ml of cocktail to achieve low detection limits. The cocktail phase is separated from the aqueous phase by use of a phase separator for liquid samples. Methods were developed for the analyses of 234 U and 238 U, the thorium nuclides 228 Th, 230 Th, 232 Th and other alpha nuclides. The achieved

Oligosaccharide binding to barley alpha-amylase 1

DEFF Research Database (Denmark)

Robert, X.; Haser, R.; Mori, H.

2005-01-01

Enzymatic subsite mapping earlier predicted 10 binding subsites in the active site substrate binding cleft of barley alpha-amylase isozymes. The three-dimensional structures of the oligosaccharide complexes with barley alpha-amylase isozyme 1 (AMY1) described here give for the first time a thorough...... in barley alpha-amylase isozyme 2 (AMY2), and the sugar binding modes are compared between the two isozymes. The "sugar tongs" surface binding site discovered in the AMY1-thio-DP4 complex is confirmed in the present work. A site that putatively serves as an entrance for the substrate to the active site...

Alpha oscillations and early stages of visual encoding

Directory of Open Access Journals (Sweden)

Wolfgang eKlimesch

2011-05-01

Full Text Available For a long time alpha oscillations have been functionally linked to the processing of visual information. Here we propose an new theory about the functional meaning of alpha. The central idea is that synchronized alpha reflects a basic processing mode that controls access to information stored in a complex long-term memory system, which we term knowledge system (KS in order to emphasize that it comprises not only declarative memories but any kind of knowledge comprising also procedural information. Based on this theoretical background, we assume that during early stages of perception, alpha ‘directs the flow of information’ to those neural structures which represent information that is relevant for encoding. The physiological function of alpha is interpreted in terms of inhibition. We assume that alpha enables access to stored information by inhibiting task irrelevant neuronal structures and by timing cortical activity in task relevant neuronal structures. We discuss a variety findings showing that evoked alpha and phase locking reflect successful encoding of global stimulus features in an early poststimulus interval of about 0 - 150 ms.

Design of a preamplifier for an alpha particles spectrometer

International Nuclear Information System (INIS)

Murillo O, R.; Hernandez D, V. M.; Chacon R, A.; Vega C, H. R.

2010-09-01

To detect radiation diverse detector types are used, when these are alpha particles proportional type detectors are used, semiconductor, of scintillation or traces. In this work the design results, the construction and the first tests of a spectrometer (preamplifier) are presented for alpha particles that was designed starting from a Pin type photodiode. The system was designed and simulated with a program for electronic circuits. With the results of the simulation phase was constructed the electronics that is coupled to a spectroscopic amplifier and a multichannel analyzer. The total of the system is evaluated analyzing its performance before a triple source of alphas and that they are produced by two smoke detectors of domestic use. Of the tests phase we find that the system allows to obtain in a multichannel, the pulses height spectrum, with which we calibrate the system. (Author)

In situ observation of transformation in alpha-Fe sub 2 O sub 3 under hydrogen implantation

CERN Document Server

Watanabe, Y; Ishikawa, N; Furuya, K; Kato, M

2002-01-01

An in situ observation of the alpha-Fe sub 2 O sub 3 -to-Fe sub 3 O sub 4 transformation has been performed using a dual-ion-beam accelerator interfaced with a transmission electron microscope (TEM). During the hydrogen-ion implantation of alpha-Fe sub 2 O sub 3 , transformation into the new phase (gamma-Fe sub 2 O sub 3 or Fe sub 3 O sub 4) was observed. It was also found that the orientation relationship between alpha-Fe sub 2 O sub 3 and the new phase (gamma-Fe sub 2 O sub 3 or Fe sub 3 O sub 4) satisfies the Shoji-Nishiyama relationship, in agreement with previous experiments. It was also found that the nearest interatomic distance does not vary by the implantation until the re-stacked phase appears, although when the re-stacked phase is formed, the lattice expansion is observed in the transformed (re-stacked) phase. Judging from these results, we have concluded that the alpha-Fe sub 2 O sub 3 to Fe sub 3 O sub 4 transformation is induced during the hydrogen ion implantation of alpha-Fe sub 2 O sub 3.

Combined zidovudine and interferon-alpha treatment in patients with AIDS-associated Kaposi's sarcoma

NARCIS (Netherlands)

de Wit, R.; Danner, S. A.; Bakker, P. J.; Lange, J. M.; Eeftinck Schattenkerk, J. K.; Veenhof, C. H.

1991-01-01

The effectiveness of addition of interferon-alpha (IFN-alpha) to zidovudine in patients with AIDS-associated Kaposi's sarcoma was assessed in a non-randomized, phase II clinical trial. Twenty-one patients were treated with oral zidovudine (600 mg daily) and IFN-alpha was increased to 18 MU daily for

Alpha particles spectrometer with photodiode PIN; Espectrometro de particulas alfa con fotodiodo PIN

Energy Technology Data Exchange (ETDEWEB)

Chacon R, A.; Hernandez V, R.; Hernandez D, V. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidades Academicas de Estudios Nucleares e Ingenieria Electrica, Calle Cipres No. 10, Fracc. La Penuela, 09869 Zacatecas (Mexico); Ramirez G, J. [Instituto Nacional de Estadistica Geografia e Informatica, Direccion General de Innovacion y Tecnologia de Informacion, Av. Heroes de Nacozari Sur 2301, Fracc. Jardines del Parque, 20276 Aguascalientes (Mexico)], e-mail: achruiz@hotmail.com

2009-10-15

The radiation propagates in form of electromagnetic waves or corpuscular radiation; if the radiation energy causes ionization in environment that crosses it is considered ionizing radiation. To detect radiation several detectors types are used, if the radiation are alpha particles are used detectors proportional type or trace elements. In this work the design results, construction and tests of an alpha particles spectrometer are presented, which was designed starting from a photodiode PIN type. The system design was simulated with a code for electronic circuits. With results of simulation phase was constructed the electronic phase that is coupled to a multichannel analyzer. The resulting electronic is evaluated analyzing the electronic circuit performance before an alphas triple source and alpha radiation that produce two smoke detectors of domestic use. On the tests phase we find that the system allows obtain, in a multichannel, the pulses height spectrum, with which we calibrate the system. (Author)

Membrane fusion and inverted phases

International Nuclear Information System (INIS)

Ellens, H.; Siegel, D.P.; Alford, D.; Yeagle, P.L.; Boni, L.; Lis, L.J.; Quinn, P.J.; Bentz, J.

1989-01-01

We have found a correlation between liposome fusion kinetics and lipid phase behavior for several inverted phase forming lipids. N-Methylated dioleoylphosphatidylethanolamine (DOPE-Me), or mixtures of dioleoylphosphatidylethanolamine (DOPE) and dioleoylphosphatidylcholine (DOPC), will form an inverted hexagonal phase (HII) at high temperatures (above TH), a lamellar phase (L alpha) at low temperatures, and an isotropic/inverted cubic phase at intermediate temperatures, which is defined by the appearance of narrow isotropic 31 P NMR resonances. The phase behavior has been verified by using high-sensitivity DSC, 31 P NMR, freeze-fracture electron microscopy, and X-ray diffraction. The temperature range over which the narrow isotropic resonances occur is defined as delta TI, and the range ends at TH. Extruded liposomes (approximately 0.2 microns in diameter) composed of these lipids show fusion and leakage kinetics which are strongly correlated with the temperatures of these phase transitions. At temperatures below delta TI, where the lipid phase is L alpha, there is little or no fusion, i.e., mixing of aqueous contents, or leakage. However, as the temperature reaches delta TI, there is a rapid increase in both fusion and leakage rates. At temperatures above TH, the liposomes show aggregation-dependent lysis, as the rapid formation of HII phase precursors disrupts the membranes. We show that the correspondence between the fusion and leakage kinetics and the observed phase behavior is easily rationalized in terms of a recent kinetic theory of L alpha/inverted phase transitions. In particular, it is likely that membrane fusion and the L alpha/inverted cubic phase transition proceed via a common set of intermembrane intermediates

Axolotl hemoglobin: cDNA-derived amino acid sequences of two alpha globins and a beta globin from an adult Ambystoma mexicanum.

Science.gov (United States)

Shishikura, Fumio; Takeuchi, Hiro-aki; Nagai, Takatoshi

2005-11-01

Erythrocytes of the adult axolotl, Ambystoma mexicanum, have multiple hemoglobins. We separated and purified two kinds of hemoglobin, termed major hemoglobin (Hb M) and minor hemoglobin (Hb m), from a five-year-old male by hydrophobic interaction column chromatography on Alkyl Superose. The hemoglobins have two distinct alpha type globin polypeptides (alphaM and alpham) and a common beta globin polypeptide, all of which were purified in FPLC on a reversed-phase column after S-pyridylethylation. The complete amino acid sequences of the three globin chains were determined separately using nucleotide sequencing with the assistance of protein sequencing. The mature globin molecules were composed of 141 amino acid residues for alphaM globin, 143 for alpham globin and 146 for beta globin. Comparing primary structures of the five kinds of axolotl globins, including two previously established alpha type globins from the same species, with other known globins of amphibians and representatives of other vertebrates, we constructed phylogenetic trees for amphibian hemoglobins and tetrapod hemoglobins. The molecular trees indicated that alphaM, alpham, beta and the previously known alpha major globin were adult types of globins and the other known alpha globin was a larval type. The existence of two to four more globins in the axolotl erythrocyte is predicted.

Lepton mixing predictions including Majorana phases from Δ(6n2 flavour symmetry and generalised CP

Directory of Open Access Journals (Sweden)

Stephen F. King

2014-09-01

Full Text Available Generalised CP transformations are the only known framework which allows to predict Majorana phases in a flavour model purely from symmetry. For the first time generalised CP transformations are investigated for an infinite series of finite groups, Δ(6n2=(Zn×Zn⋊S3. In direct models the mixing angles and Dirac CP phase are solely predicted from symmetry. The Δ(6n2 flavour symmetry provides many examples of viable predictions for mixing angles. For all groups the mixing matrix has a trimaximal middle column and the Dirac CP phase is 0 or π. The Majorana phases are predicted from residual flavour and CP symmetries where α21 can take several discrete values for each n and the Majorana phase α31 is a multiple of π. We discuss constraints on the groups and CP transformations from measurements of the neutrino mixing angles and from neutrinoless double-beta decay and find that predictions for mixing angles and all phases are accessible to experiments in the near future.

Lepton mixing predictions including Majorana phases from Δ(6n2) flavour symmetry and generalised CP

International Nuclear Information System (INIS)

King, Stephen F.; Neder, Thomas

2014-01-01

Generalised CP transformations are the only known framework which allows to predict Majorana phases in a flavour model purely from symmetry. For the first time generalised CP transformations are investigated for an infinite series of finite groups, Δ(6n 2 )=(Z n ×Z n )⋊S 3 . In direct models the mixing angles and Dirac CP phase are solely predicted from symmetry. The Δ(6n 2 ) flavour symmetry provides many examples of viable predictions for mixing angles. For all groups the mixing matrix has a trimaximal middle column and the Dirac CP phase is 0 or π. The Majorana phases are predicted from residual flavour and CP symmetries where α 21 can take several discrete values for each n and the Majorana phase α 31 is a multiple of π. We discuss constraints on the groups and CP transformations from measurements of the neutrino mixing angles and from neutrinoless double-beta decay and find that predictions for mixing angles and all phases are accessible to experiments in the near future

Phase stability and decomposition processes in Ti-Al based intermetallics

Energy Technology Data Exchange (ETDEWEB)

Nakai, Kiyomichi [Department of Materials Science and Engineering, Faculty of Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama 790 (Japan); Ono, Toshiaki [Department of Materials Science and Engineering, Faculty of Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama 790 (Japan); Ohtsubo, Hiroyuki [Department of Materials Science and Engineering, Faculty of Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama 790 (Japan); Ohmori, Yasuya [Department of Materials Science and Engineering, Faculty of Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama 790 (Japan)

1995-02-28

The high-temperature phase equilibria and the phase decomposition of {alpha} and {beta} phases were studied by crystallographic analysis of the solidification microstructures of Ti-48at.%Al and Ti-48at.%Al-2at.%X (X=Mn, Cr, Mo) alloys. The effects on the phase stability of Zr and O atoms penetrating from the specimen surface were also examined for Ti-48at.%Al and Ti-50at.%Al alloys. The third elements Cr and Mo shift the {beta} phase region to higher Al concentrations, and the {beta} phase is ordered to the {beta}{sub 2} phase. The Zr and O atoms stabilize {beta} and {alpha} phases respectively. In the Zr-stabilized {beta} phase, {alpha}{sub 2} laths form with accompanying surface relief, and stacking faults which relax the elastic strain owing to lattice deformation are introduced after formation of {alpha}{sub 2} order domains. Thus shear is thought to operate after the phase transition from {beta} to {alpha}{sub 2} by short-range diffusion. A similar analysis was conducted for the Ti-Al binary system, and the transformation was interpreted from the CCT diagram constructed qualitatively. ((orig.))

Effects of internally deposited alpha emitters

International Nuclear Information System (INIS)

Rundo, J.; Schlenker, R.A.; Stebbings, J.H.

1985-01-01

This study seeks to identify and quantify the human health effects of occupational exposures to radium, use the health effects data from the radium study to predict responses to other alpha-emitting and/or bone-seeking radionuclides at occupational exposure levels and above, and predict the effects of these radionuclides, specifically environmental radium and its daughters, at nonoccupational exposure levels. 14 refs

Age-hardening and related phase transformation in an experimental Ag-Cu-Pd-Au alloy

Energy Technology Data Exchange (ETDEWEB)

Seol, Hyo-Joung [Department of Dental Materials, College of Dentistry, Pusan National University, 1-10 Ami-dong, Seo-gu, Pusan 602-739 (Korea, Republic of); Lee, Doung-Hun [Department of Dental Materials, College of Dentistry, Pusan National University, 1-10 Ami-dong, Seo-gu, Pusan 602-739 (Korea, Republic of); Lee, Hee-Kyung [Department of Dental Technology, Daegu Health College, San 7 Taejeon-dong, Buk-gu, Daegu 702-722 (Korea, Republic of); Takada, Yukyo [Division of Dental Biomaterials, Graduate School of Dentistry, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan); Okuno, Osamu [Division of Dental Biomaterials, Graduate School of Dentistry, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan); Kwon, Yong Hoon [Department of Dental Materials, College of Dentistry, Pusan National University, 1-10 Ami-dong, Seo-gu, Pusan 602-739 (Korea, Republic of); Kim, Hyung-Il [Department of Dental Materials, College of Dentistry, Pusan National University, 1-10 Ami-dong, Seo-gu, Pusan 602-739 (Korea, Republic of)]. E-mail: hilkim@pusan.ac.kr

2006-01-05

The age-hardening behaviour, phase transformation and related microstructural changes of an experimental Ag-Cu-Pd-Au alloy were examined by means of hardness test, X-ray diffraction (XRD), scanning electron microscopic (SEM) observations and electron probe microanalysis (EPMA). The specimen alloy showed apparent age-hardenability at the aging temperatures of 350 deg. C and 400 deg. C. By aging the solution-treated specimen at 400 deg. C, two phases of the Ag-rich {alpha}{sub 1} phase and the Pd-containing Cu-rich {alpha}{sub 2} phase were transformed into four phases of the Ag-rich {alpha}{sub 1}{sup '} phase, the Cu-rich {alpha}{sub 2}{sup '} phase, the CsCl-type CuPd phase and the AuCu(I) ordered phase. Microstructure of the solution-treated specimen consisted of the Ag-rich {alpha}{sub 1} matrix, Cu-rich {alpha}{sub 2} particle-like structures of various sizes and the lamellar structure of the {alpha}{sub 1} and {alpha}{sub 2} phases. When the peak hardness was obtained, the very fine lamellar structure consisting of the Ag-rich {alpha}{sub 1}{sup '} and Cu-rich {alpha}{sub 2}{sup '} phases was newly formed in the matrix. By further aging, the very fine lamellar structure grew and coarsened apparently, and the matrix was covered with the coarsened lamellar structure. The hardness increase was considered to be caused mainly by the diffusion and precipitation of Cu from the Ag-rich {alpha}{sub 1} matrix, and the hardness decrease in the latter stage of age-hardening process was caused by the coarsening of the very fine lamellar structure. The CsCl-type CuPd phase and the AuCu(I) ordered phase did not contribute to the hardness increase.

A randomized phase II chemoprevention trial of 13-CIS retinoic acid with or without alpha tocopherol or observation in subjects at high risk for lung cancer.

Science.gov (United States)

Kelly, Karen; Kittelson, John; Franklin, Wilbur A; Kennedy, Timothy C; Klein, Catherine E; Keith, Robert L; Dempsey, Edward C; Lewis, Marina; Jackson, Mary K; Hirsch, Fred R; Bunn, Paul A; Miller, York E

2009-05-01

No chemoprevention strategies have been proven effective for lung cancer. We evaluated the effect of 13-cis retinoic acid (13-cis RA), with or without alpha tocopherol, as a lung cancer chemoprevention agent in a phase II randomized controlled clinical trial of adult subjects at high risk for lung cancer as defined by the presence of sputum atypia, history of smoking, and airflow obstruction, or a prior surgically cured nonsmall cell lung cancer (disease free, >3 years). Subjects were randomly assigned to receive either 13-cis RA, 13-cis RA plus alpha tocopherol (13-cis RA/alpha toco) or observation for 12 months. Outcome measures are derived from histologic evaluation of bronchial biopsy specimens obtained by bronchoscopy at baseline and follow-up. The primary outcome measure is treatment "failure" defined as histologic progression (any increase in the maximum histologic score) or failure to return for follow-up bronchoscopy. Seventy-five subjects were randomized (27/22/26 to observations/13-cis RA/13-cis RA/alpha toco); 59 completed the trial; 55 had both baseline and follow-up bronchoscopy. The risk of treatment failure was 55.6% (15 of 27) and 50% (24 of 48) in the observation and combined (13 cis RA plus 13 cis RA/alpha toco) treatment arms, respectively (odds ratio adjusted for baseline histology, 0.97; 95% confidence interval, 0.36-2.66; P = 0.95). Among subjects with complete histology data, maximum histology score in the observation arm increased by 0.37 units and by 0.03 units in the treated arms (difference adjusted for baseline, -0.18; 95% confidence interval, -1.16 to 0.81; P = 0.72). Similar (nonsignificant) results were observed for treatment effects on endobronchial proliferation as assessed by Ki-67 immunolabeling. Twelve-month treatment with 13-cis RA produced nonsignificant changes in bronchial histology, consistent with results in other trials. Agents advancing to phase III randomized trials should produce greater histologic changes. The

The ALPHA Experiment a Cold Antihydrogen Trap

CERN Document Server

Bertsche, W; Bowe, P D; Cesar, C L; Chapman, S; Charlton, M; Chartier, M; Deutsch, A; Fajans, J; Fujiwara, M C; Funakoshi, R; Gill, D; Gomberoff, K; Grote, D P; Hangst, J S; Hayano, R S; Jenkins, M; Jørgensen, L V; Madsen, N; Miranda, D; Nolan, P; Ochanski, K; Olin, A; Page, R D; Posada, L G C; Robicheaux, F; Sarid, E; Telle, H H; Vay, J L; Wurtele, J; van der Werf, D P; Yamazaki, Y

2005-01-01

The ALPHA experiment aims to trap antihydrogen as the next crucial step towards a precise CPT test, by a spectroscopic comparison of antihydrogen with hydrogen. The experiment will retain the salient techniques developed by the ATHENA collaboration during the previous phase of antihydrogen experiments at the antiproton decelerator (AD) at CERN. The collaboration has identified the key problems in adding a neutral antiatom trap to the previously developed experimental configuration. The solutions identified by ALPHA are described in this paper.

The thermal structural transition of alpha-crystallin modulates subunit interactions and increases protein solubility.

Directory of Open Access Journals (Sweden)

Giuseppe Maulucci

Full Text Available BACKGROUND: Alpha crystallin is an oligomer composed of two types of subunits, alpha-A and alpha-B crystallin, and is the major constituent of human lens. The temperature induced condensation of alpha-crystallin, the main cause for eye lens opacification (cataract, is a two step-process, a nucleation followed by an aggregation phase, and a protective effect towards the aggregation is exhibited over the alpha crystallin phase transition temperature (Tc = 318.16 K. METHODS/RESULTS: To investigate if a modulation of the subunit interactions over Tc could trigger the protective mechanism towards the aggregation, we followed, by using simultaneously static and dynamic light scattering, the temperature induced condensation of alpha-crystallin. By developing a mathematical model able to uncouple the nucleation and aggregation processes, we find a previously unobserved transition in the nucleation rate constant. Its temperature dependence allows to determine fundamental structural parameters, the chemical potential (Δμ and the interfacial tension (γ of the aggregating phase, that characterize subunit interactions. CONCLUSIONS/GENERAL SIGNIFICANCE: The decrease of both Δμ and γ at Tc, and a relative increase in solubility, reveal a significative decrease in the strenght of alpha-crystallin subunits interactions, which protects from supramolecolar condensation in hypertermic conditions. On the whole, we suggest a general approach able to understand the structural and kinetic mechanisms involved in aggregation-related diseases and in drugs development and testing.

A Novel Model Predictive Control for Single-Phase Grid-Connected Photovoltaic Inverters

DEFF Research Database (Denmark)

Zangeneh Bighash, Esmaeil; Sadeghzadeh, Seyed Mohammad; Ebrahimzadeh, Esmaeil

2017-01-01

Single-phase grid-connected inverters with LCL filter are widely used to connect photovoltaic systems to the utility grid. Among the existing control schemes, predictive control methods are faster and more accurate but also more complicated to implement. Recently, the Model Predictive Control (MPC......) algorithm for single-phase inverter has been presented, where the algorithm implementation is straightforward. In the MPC approach, all switching states are considered in each switching period to achieve the control objectives. However, since the number of switching states in single-phase inverters is small......, the inverter output current has a high Total Harmonic Distortions (THD). In order to reduce this, this paper presents an improved MPC for single-phase grid-connected inverters. In the proposed approach, the switching algorithm is changed and the number of the switching states is increased by means of virtual...

Characterization of Makrofol ® DE 1-1 for alpha particle radiography

Science.gov (United States)

El Ghazaly, M.; Aydarous, Abdulkadir; Al-Thomali, Talal A.

2017-09-01

Makrofol ® DE 1-1 (bisphenol-A polycarbonate) was investigated for alpha particle radiography. The edge spread function (ESF) was measured by razor-blade's edge. Makrofol ® DE 1-1 detectors were irradiated with perpendicular incident alpha particles of energy 2.5, 4 and 5.4 MeV, thereafter they were etched in 75% 6N KOH+25% C2H5OH at a temperature of 50 °C for different durations. The etched Makrofol®DE 1-1 detectors were imaged with an optical microscope equipped with a CCD camera. The results revealed that the green channel of the original RGB image provides the highest contrast comparing with red and blue channel by a factor of 27.6% of the original RGB image. The image contrast of alpha particle-irradiated Makrofol®DE 1-1 detector was found to be inversely related to the etching time since the alpha particle tracks proceed from a conical phase to spherical phase. The spatial resolution of alpha particle-irradiated Makrofol®DE 1-1 detector, in terms of line spread function, was found to deteriorate as the etching time increases for all examined alpha particle energies. The results revealed the potential capability of Makrofol®DE 1-1 detector as an efficient detector for alpha particle radiography such as autoradiography.

Producing a compound Nucleus via Inelastic Scattering: The 90Zr(alpha,alpha')90Zr* Case

Energy Technology Data Exchange (ETDEWEB)

Escher, J E; Dietrich, F S

2008-05-23

In a Surrogate reaction a compound nucleus is produced via a direct reaction (pickup, stripping, or inelastic scattering). For a proper application of the Surrogate approach it is necessary to predict the resulting angular momentum and parity distribution in the compound nucleus. A model for determining these distributions is developed for the case of inelastic alpha scattering off a spherical nucleus. The focus is on obtaining a first, simple description of the direct-reaction process that produces the compound nucleus and on providing the basis for a more complete treatment of the problem. The approximations employed in the present description are discussed and the extensions required for a more rigorous treatment of the problem are outlined. To illustrate the formalism, an application to {sup 90}Zr({alpha},{alpha}{prime}){sup 90}Zr* is presented.

Automatic spark counting of alpha-tracks in plastic foils

International Nuclear Information System (INIS)

Somogyi, G.; Medveczky, L.; Hunyadi, I.; Nyako, B.

1976-01-01

The possibility of alpha-track counting by jumping spark counter in cellulose acetate and polycarbonate nuclear track detectors was studied. A theoretical treatment is presented which predicts the optimum residual thickness of the etched foils in which completely through-etched tracks (i.e. holes) can be obtained for alpha-particles of various energies and angles of incidence. In agreement with the theoretical prediction it is shown that a successful spark counting of alpha-tracks can be performed even in polycarbonate foils. Some counting characteristics, such as counting efficiency vs particle energy at various etched foil thicknesses, surface spark density produced by electric breakdowns in unexposed foils vs foil thickness, etc. have been determined. Special attention was given to the spark counting of alpha-tracks entering thin detectors at right angle. The applicability of the spark counting technique is demonstrated in angular distribution measurements of the 27 Al(p,α 0 ) 24 Mg nuclear reaction at Ep = 1899 keV resonance energy. For this study 15 μm thick Makrofol-G foils and a jumping spark counter of improved construction were used. (orig.) [de

A microcantilever investigation of size effect, solid-solution strengthening and second-phase strengthening for prism slip in alpha-Ti

Energy Technology Data Exchange (ETDEWEB)

Gong Jicheng, E-mail: jicheng.gong@materials.ox.ac.uk [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Wilkinson, Angus J. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)

2011-09-15

Microcantilevers of various sizes were machined using a focused ion beam from commercially pure (CP) Ti, Ti-6Al and Ti-6Al-4V, and tested in bending using a nanoindentor in order to study the size effect, solution strengthening and second-phase strengthening in {alpha}-Ti. Slip on the prismatic system was activated by selecting the crystal orientation of {alpha}-phase in the cantilevers. The critical resolved shear stresses (CRSSs) were determined via an inverse process of fitting a crystal plasticity finite element model to the experimental load-displacement data. Cantilevers had an equilateral triangular cross-section and cantilevers with widths w of 10, 5, 2 and 1 {mu}m were tested. For each material the increase in CRSS {tau} with reducing cantilever width w is represented well by the expression {tau}={tau}{sub 0}+A/w , where {tau}{sub 0} is the CRSS for an infinite sample and A is a constant. Such a variation of CRSS with beam size is well accounted for by the increased back stress generated by dislocations piling up at the neutral axis. The CRSS values extrapolated to infinite sample size are 86 MPa for the CP-Ti, 308 MPa for the Ti-6Al and 444 MPa for the slip in the Ti-6Al-4V.

Hot ductility behavior of near-alpha titanium alloy IMI834

International Nuclear Information System (INIS)

Ghavam, Mohammad Hadi; Morakabati, Maryam; Abbasi, Seyed Mahdi; Badri, Hassan

2014-01-01

The hot ductility of rolled IMI834 titanium alloy (Ti-5.3Al-2.9Sn-3.0Zr-0.65Nb-0.5Mo-0.2Si in wt%) has been studied by conducting tensile tests with a strain rate of 0.1 s -1 and temperature range of 750-1100 C to obtain the optimum hot working conditions. The alloy showed minimum hot ductility in the lower alpha-beta region in the temperature range 750-950 C. Further microstructural characterizations showed improvement in hot ductility by increasing temperature, which was attributed to reduction of volume fraction of high strength alpha phase. The best hot ductility was observed at 1000 C, i.e. in the upper alpha-beta region. The better hot ductility at higher temperature could be related to the increase in the volume fraction of beta phase and the occurrence of dynamic restoration phenomena. The second decline in hot ductility appeared at higher temperatures in the beta region and was attributed to the high stacking fault energy and self-diffusion of beta phase leading to limitation of dynamic recrystallization.

Contingency of alpha decay in 287-306120 isotopes of SHE

International Nuclear Information System (INIS)

Carmel Vigila Bai, G.M.; Umai Parvathiy, J.

2014-01-01

In recent years the synthesis and identification of super heavy nuclei has a particular attention in the field of nuclear physics. Many theoretical calculations have been done to study the properties of even-Z Super heavy elements (SHE). Durate et al. applied the effective liquid drop model to predict the alpha decay, cluster emission and cold fission half-life values of nuclei on the region of super heavy elements, defined by 155 ≤ N ≤ 220 and 110 ≤ Z ≤ 135. In the case of super heavy elements spontaneous fission and alpha decay are the main decay modes. Super heavy nuclei which have relatively small alpha decay half times compared to spontaneous fission half lives will survive fission and thus can be detected in the laboratory through α-decay. The present paper aims to predict possibility of alpha decay in the element Z = 120 isotopes using CYE model and the spontaneous fission half lives are computed using the phenomenological formula

A discriminatory function for prediction of protein-DNA interactions based on alpha shape modeling.

Science.gov (United States)

Zhou, Weiqiang; Yan, Hong

2010-10-15

Protein-DNA interaction has significant importance in many biological processes. However, the underlying principle of the molecular recognition process is still largely unknown. As more high-resolution 3D structures of protein-DNA complex are becoming available, the surface characteristics of the complex become an important research topic. In our work, we apply an alpha shape model to represent the surface structure of the protein-DNA complex and developed an interface-atom curvature-dependent conditional probability discriminatory function for the prediction of protein-DNA interaction. The interface-atom curvature-dependent formalism captures atomic interaction details better than the atomic distance-based method. The proposed method provides good performance in discriminating the native structures from the docking decoy sets, and outperforms the distance-dependent formalism in terms of the z-score. Computer experiment results show that the curvature-dependent formalism with the optimal parameters can achieve a native z-score of -8.17 in discriminating the native structure from the highest surface-complementarity scored decoy set and a native z-score of -7.38 in discriminating the native structure from the lowest RMSD decoy set. The interface-atom curvature-dependent formalism can also be used to predict apo version of DNA-binding proteins. These results suggest that the interface-atom curvature-dependent formalism has a good prediction capability for protein-DNA interactions. The code and data sets are available for download on http://www.hy8.com/bioinformatics.htm kenandzhou@hotmail.com.

Scattering of alpha particles from /sup 12/C and the /sup 12/C(. cap alpha. ,. gamma. )/sup 16/O stellar reaction rate

Energy Technology Data Exchange (ETDEWEB)

Plaga, R.; Becker, H.W.; Redder, A.; Rolfs, C.; Trautvetter, H.P.; Langanke, K.

1987-04-06

The elastic scattering of alpha particles from /sup 12/C has been investigated for 35 angles in the range theta/sub lab/ = 22/sup 0/ to 163/sup 0/ and for 51 energies at E/sub ..cap alpha../ = 1.0 to 6.6 MeV. The extracted phase shifts for l=0 to 6 partial waves have been parametrized in terms of the multilevel R-matrix formalism. Information on the deduced parameters of states in /sup 16/O is reported. The data reveal reduced ..cap alpha..-particle widths for the 6.92 and 7.12 MeV subthreshold states consistent with recent work. The implications for the stellar reaction rate of /sup 12/C(..cap alpha..,..gamma..)/sup 16/O are discussed.

Phonon anharmonicity and Gruneisen parameters of alpha-plutonium

International Nuclear Information System (INIS)

Filanovich, A.N.; Povzner, A.A.

2015-01-01

A self-consistent thermodynamic model of alpha-phase of plutonium is constructed. The calculations of thermal and elastic properties of α-Pu, carried out within this model, demonstrate that anomalously strong temperature dependence of the bulk modulus and unusually high value of the coefficient of thermal expansion of α-Pu are caused by its strong lattice anharmonicity. The isothermal and isobaric Gruneisen parameters of α-Pu and δ-Pu Pu_0_._9_6Ga_0_._0_4 are calculated. It is shown that wide spread of the values of Gruneisen parameter of α-Pu, obtained previously from different experimental data, is explained by the dependence of Gruneisen parameter of α-Pu on temperature. - Highlights: • A self-consistent thermodynamic model of alpha-plutonium is developed. • Thermal and elastic properties of alpha-plutonium are calculated. • The reason of spread in the values of Gruneisen parameter of alpha-Pu is established. • Different types of phonon anharmonicity in alpha-Pu and delta-Pu are revealed.

Low temperature synthesis of nano alpha-alumina powder by two-step hydrolysis

International Nuclear Information System (INIS)

Yan, Ting; Guo, Xiaode; Zhang, Xiang; Wang, Zhixiang; Shi, Jinqiu

2016-01-01

Highlights: • The nano α-Al 2 O 3 with good dispersion was prepared by two-step hydrolysis. • α-Al 2 O 3 powders were added as seed particles in the hydrolysis. • This article indicated that the glucose could impel the γ-Al 2 O 3 transformed to α-Al 2 O 3 directly. • This article indicated that the addictive of α-Al 2 O 3 seed could improve the phase transformation rate of γ-Al 2 O 3 to α-Al 2 O 3 . • In this article, the pure α-Al 2 O 3 could be obtained by calcining at 1000 °C for 1.5 h. - Abstract: The ultral fine alpha-alumina powder has been successfully synthesized via two-step hydrolysis of aluminum isopropoxide. Glucose and polyvinyl pyrrolidone were used as surfactants during the appropriate processing step. The alpha-alumina powder was used as seed particles. Several synthesis parameters, such as the amount of seeds, surfactants, and calcination temperature, were studied by X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), Thermogravimetry-differential scanning calorimetry (TG-DSC), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The experimental results showed that glucose greatly lower the phase transformation temperature of alpha-alumina by impelling the gamma-alumina transformed to alpha-alumina directly, and the seed could improve the phase transformation rate of alpha-alumina, the polyvinylpyrrolidone have an effect on preventing excessive grain growth and agglomeration of alpha-alumina powder. Comparatively well dispersed alpha-alumina powder with particle size less than 50 nm can be synthesized through this method after calcinations at 1000 °C for 2 h.

Effects of TNF-alpha on Endothelial Cell Collective Migration

Science.gov (United States)

Chen, Desu; Wu, Di; Helim Aranda-Espinoza, Jose; Losert, Wolfgang

2013-03-01

Tumor necrosis factor (TNF-alpha) is a small cell-signaling protein usually released by monocytes and macrophages during an inflammatory response. Previous work had shown the effects of TNF-alpha on single cell morphology, migration, and biomechanical properties. However, the effect on collective migrations remains unexplored. In this work, we have created scratches on monolayers of human umbilical endothelial cells (HUVECs) treated with 25ng/mL TNF-alpha on glass substrates. The wound healing like processes were imaged with phase contrast microscopy. Quantitative analysis of the collective migration of cells treated with TNF-alpha indicates that these cells maintain their persistent motion and alignment better than untreated cells. In addition, the collective migration was characterized by measuring the amount of non-affine deformations of the wound healing monolayer. We found a lower mean non-affinity and narrower distribution of non-affinities upon TNF-alpha stimulation. These results suggest that TNF-alpha introduces a higher degree of organized cell collective migration.

Pretest Predictions for Phase II Ventilation Tests

International Nuclear Information System (INIS)

Yiming Sun

2001-01-01

The objective of this calculation is to predict the temperatures of the ventilating air, waste package surface, and concrete pipe walls that will be developed during the Phase II ventilation tests involving various test conditions. The results will be used as inputs to validating numerical approach for modeling continuous ventilation, and be used to support the repository subsurface design. The scope of the calculation is to identify the physical mechanisms and parameters related to thermal response in the Phase II ventilation tests, and describe numerical methods that are used to calculate the effects of continuous ventilation. The calculation is limited to thermal effect only. This engineering work activity is conducted in accordance with the ''Technical Work Plan for: Subsurface Performance Testing for License Application (LA) for Fiscal Year 2001'' (CRWMS M and O 2000d). This technical work plan (TWP) includes an AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', activity evaluation (CRWMS M and O 2000d, Addendum A) that has determined this activity is subject to the YMP quality assurance (QA) program. The calculation is developed in accordance with the AP-3.12Q procedure, ''Calculations''. Additional background information regarding this activity is contained in the ''Development Plan for Ventilation Pretest Predictive Calculation'' (DP) (CRWMS M and O 2000a)

Predicting alpha diversity of African rain forests: models based on climate and satellite-derived data do not perform better than a purely spatial model

NARCIS (Netherlands)

Parmentier, I.; Harrigan, R.; Buermann, W.; Mitchard, E.T.A.; Saatchi, S.; Malhi, Y.; Bongers, F.; Hawthorne, W.D.; Leal, M.E.; Lewis, S.; Nusbaumer, L.; Sheil, D.; Sosef, M.S.M.; Bakayoko, A.; Chuyong, G.; Chatelain, C.; Comiskey, J.; Dauby, G.; Doucet, J.L.; Hardy, O.

2011-01-01

Aim Our aim was to evaluate the extent to which we can predict and map tree alpha diversity across broad spatial scales either by using climate and remote sensing data or by exploiting spatial autocorrelation patterns. Location Tropical rain forest, West Africa and Atlantic Central Africa. Methods

Refractometry characteristics of {alpha}-quartz after neutron irradiation; Refraktometrichaskie kharakteristiki {alpha}-kvartsa posle oblucheniya nejtronami

Energy Technology Data Exchange (ETDEWEB)

Abdkadyrova, I Kh [AN RU, Tashkent (Uzbekistan). Inst. Yadernoj Fiziki

1997-02-01

Lattice structure distortions in irradiated crystalline quartz were studied by refractometry methods. The refractometry constants of {alpha}-quartz for the flux of fast neutrons 10{sup 18} - 10{sup 21} neutron/cm{sup 2} were calculated. The critical kinetics of this constants at the phase transformation is observed.(author). 5 refs., 1 fig.

Far-Infrared and Millimeter Continuum Studies of K-Giants: Alpha Boo and Alpha Tau

Science.gov (United States)

Cohen, Martin; Carbon, Duane F.; Welch, William J.; Lim, Tanya; Forster, James R.; Goorvitch, David; Thigpen, William (Technical Monitor)

2002-01-01

We have imaged two normal, non-coronal, infrared-bright K-giants, alpha Boo and alpha Tau, in the 1.4-millimeter and 2.8-millimeter continuum using BIMA. These stars have been used as important absolute calibrators for several infrared satellites. Our goals are: (1) to probe the structure of their upper photospheres; (2) to establish whether these stars radiate as simple photospheres or possess long-wavelength chromospheres; and (3) to make a connection between millimeter-wave and far-infrared absolute flux calibrations. To accomplish these goals we also present ISO Long Wavelength Spectrometer (LWS) measurements of both these K-giants. The far-infrared and millimeter continuum radiation is produced in the vicinity of the temperature minimum in a Boo and a Tau, offering a direct test of the model photospheres and chromospheres for these two cool giants. We find that current photospheric models predict fluxes in reasonable agreement with those observed for those wavelengths which sample the upper photosphere, namely less than or equal to 170 micrometers in alpha Tau and less than or equal to 125 micrometers in alpha Boo. It is possible that alpha Tau is still radiative as far as 0.9 - 1.4 millimeters. We detect chromospheric radiation from both stars by 2.8 millimeters (by 1.4 millimeters in alpha Boo), and are able to establish useful bounds on the location of the temperature minimum. An attempt to interpret the chromospheric fluxes using the two-component "bifurcation model" proposed by Wiedemann et al. (1994) appears to lead to a significant contradiction.

[Isolation and purification of alpha-glycerophosphate oxidase in a polyethylene glycol/(NH4 )2SO4 aqueous two-phase system].

Science.gov (United States)

Meng, Yao; Jin, Jiagui; Liu, Shuangfeng; Yang, Min; Zhang, Qinglian; Wan, Li; Tang, Kun

2014-02-01

Alpha-glycerophosphate oxidase (alpha-GPO) from Enterococcus casseli flavus was successfully isolated and purified by using polyethylene glycol (PEG)/(NH4)2SO4 aqueous two-phase system (ATPS). The results showed that the chosen PEG/(NH4)2SO4 ATPS could be affected by PEG molecular weight, pH, concentration of PEG and (NH4)2SO4, and inorganic salt as well as additional amount of crude enzyme. After evaluating these influencing factors, the final optimum purification strategy was formed by 16.5% (m/m) PEG2000, 13.2% (m/m) (NH4)2SO4, pH 7.5 and 30% (m/m) additive crude enzyme, respectively. The NaCl was a negative influencing factor which would lead to lower purification fold and activity recovery. These conditions eventually resulted in the activity recovery of 89% (m/m), distribution coefficient of 1.2 and purification fold of 7.0.

Prediction of two-phase mixture density using artificial neural networks

International Nuclear Information System (INIS)

Lombardi, C.; Mazzola, A.

1997-01-01

In nuclear power plants, the density of boiling mixtures has a significant relevance due to its influence on the neutronic balance, the power distribution and the reactor dynamics. Since the determination of the two-phase mixture density on a purely analytical basis is in fact impractical in many situations of interest, heuristic relationships have been developed based on the parameters describing the two-phase system. However, the best or even a good structure for the correlation cannot be determined in advance, also considering that it is usually desired to represent the experimental data with the most compact equation. A possible alternative to empirical correlations is the use of artificial neural networks, which allow one to model complex systems without requiring the explicit formulation of the relationships existing among the variables. In this work, the neural network methodology was applied to predict the density data of two-phase mixtures up-flowing in adiabatic channels under different experimental conditions. The trained network predicts the density data with a root-mean-square error of 5.33%, being ∼ 93% of the data points predicted within 10%. When compared with those of two conventional well-proven correlations, i.e. the Zuber-Findlay and the CISE correlations, the neural network performances are significantly better. In spite of the good accuracy of the neural network predictions, the 'black-box' characteristic of the neural model does not allow an easy physical interpretation of the knowledge integrated in the network weights. Therefore, the neural network methodology has the advantage of not requiring a formal correlation structure and of giving very accurate results, but at the expense of a loss of model transparency. (author)

Excitation functions for alpha-particle-induced reactions with natural antimony

Energy Technology Data Exchange (ETDEWEB)

Singh, N. L.; Shah, D. J.; Mukherjee, S.; Chintalapudi, S. N. [Vadodara, M. S. Univ. of Baroda (India). Fac. of Science. Dept. of Physics

1997-07-01

Stacked-foil activation technique and {gamma} - rays spectroscopy were used for the determination of the excitation functions of the {sup 121}Sb [({alpha}, n); ({alpha}, 2n); ({alpha},4 n); ({alpha}, p3n); ({alpha}, {alpha}n)]; and Sb [({alpha}, 3n); ({alpha}, 4n); ({alpha}, {alpha}3n)] reactions. The excitation functions for the production of {sup 124}I, {sup 123}I, {sup 121}I, {sup 121}Te and {sup 120}Sb were reported up to 50 MeV. The reactions {sup 121} Sb ({alpha}, {alpha}n) + {sup 123} Sb ({alpha}, {alpha}3n) are measured for the first time. Since natural antimony used as the target has two odd mass stable isotopes of abundances 57.3 % ({sup 121}Sb), their activation in some cases gives the same product nucleus through different reaction channels but with very different Q-values. In such cases, the individual reaction cross-sections are separated with the help of theoretical cross-sections. The experimental cross-sections were compared with the predictions based on hybrid model of Blann. The high-energy part of the excitation functions are dominated by the pre-equilibrium reaction mechanism and the initial exciton number n{sub 0} = 4 (4 p 0 h) gives fairly good agreement with presently measured results.

Lack of co-ordinate expression of the alpha1(I) and alpha1(III) procollagen genes in fibroblast clonal cultures.

Science.gov (United States)

Yamaguchi, Y; Crane, S; Zhou, L; Ochoa, S M; Falanga, V

2000-12-01

Several extracellular matrix genes, most notably alpha1(I) and alpha1(III) procollagen, are reported to be co-ordinately expressed in cultures of dermal fibroblasts. However, it remains unclear whether the expression of these genes is truly co-ordinate or whether it may be the result of averaging the phenotypic expression of different fibroblast subpopulations present within each culture. Objectives To determine by Northern analysis the correlation between alpha1(I) and alpha1(III) procollagen mRNA levels in clonal populations of human dermal fibroblasts. As previously described, clonal cultures were derived from parent strains of human dermal fibroblasts by a microscopically controlled dilution technique and by stimulation of single cells with low oxygen tension in the early phases of clonal growth. In agreement with previous reports, we found that baseline steady-state levels of alpha1(I) procollagen mRNA were co-ordinately regulated with the alpha1(III) procollagen mRNA in 26 parent strains (r = 0. 9003; P ordinate regulation observed in non-clonal cultures, suggesting that these two genes operate under different sets of regulatory controls. This clonal heterogeneity may provide additional flexibility to the process of tissue repair and fibroblast clonal expansion.

Investigation of spin-reorientation phase transitions at surface and in volume of alpha-Fe sub 2 O sub 3 monocrystals

CERN Document Server

Kamzin, A S

2002-01-01

The magnetic structure of the surface layer and volume and the processes, observed by the spin-reorientation phase transition (SRPT), are studied in the direct comparison of the properties of the thin surface layer and the volume of the hematite (alpha-Fe sub 2 O sub 3) macroscopic crystals. The method of simultaneous gamma, X-ray and electron Moessbauer spectroscopy was used in the studies. The direct data on the existence of the transition layer on the hematite crystals surface are obtained. It is established, that the Morin-type SRPT in the sample volume occurs by a jump (the first-order phase transition). The SRPT in the surface layer as well as in the crystal volume is accompanied by formation of the intermediate state, wherein the low- and high-temperature phases coexist. The obtained experimental data on the SRPT mechanism in the surface layer agree well with the conclusions of the phenomenological theory

Metallographic Study of the Isothermal Transformation of Beta Phase in Zircaloy-2

Energy Technology Data Exchange (ETDEWEB)

Oestberg, G

1960-06-15

Observations of the structure of commercial zircaloy-2 have been made in the microscope showing that the high temperature beta phase is transformed isothermally at lower temperatures into alpha plus secondary precipitate. The alpha occurs mainly as Widmanstaetten plates developed by a shear mechanism. The secondary precipitate is formed from the beta - alpha structure at the phase boundary between these phases. This precipitation of particles of secondary phase occurs on account of a eutectoid reaction, alpha also being formed. A time-temperature transformation diagram has been constructed from the observations.

Isoporphyrin intermediate in heme oxygenase catalysis. Oxidation of alpha-meso-phenylheme.

Science.gov (United States)

Evans, John P; Niemevz, Fernando; Buldain, Graciela; de Montellano, Paul Ortiz

2008-07-11

Human heme oxygenase-1 (hHO-1) catalyzes the O2- and NADPH-dependent oxidation of heme to biliverdin, CO, and free iron. The first step involves regiospecific insertion of an oxygen atom at the alpha-meso carbon by a ferric hydroperoxide and is predicted to proceed via an isoporphyrin pi-cation intermediate. Here we report spectroscopic detection of a transient intermediate during oxidation by hHO-1 of alpha-meso-phenylheme-IX, alpha-meso-(p-methylphenyl)-mesoheme-III, and alpha-meso-(p-trifluoromethylphenyl)-mesoheme-III. In agreement with previous experiments (Wang, J., Niemevz, F., Lad, L., Huang, L., Alvarez, D. E., Buldain, G., Poulos, T. L., and Ortiz de Montellano, P. R. (2004) J. Biol. Chem. 279, 42593-42604), only the alpha-biliverdin isomer is produced with concomitant formation of the corresponding benzoic acid. The transient intermediate observed in the NADPH-P450 reductase-catalyzed reaction accumulated when the reaction was supported by H2O2 and exhibited the absorption maxima at 435 and 930 nm characteristic of an isoporphyrin. Product analysis by reversed phase high performance liquid chromatography and liquid chromatography electrospray ionization mass spectrometry of the product generated with H2O2 identified it as an isoporphyrin that, on quenching, decayed to benzoylbiliverdin. In the presence of H218O2, one labeled oxygen atom was incorporated into these products. The hHO-1-isoporphyrin complexes were found to have half-lives of 1.7 and 2.4 h for the p-trifluoromethyl- and p-methyl-substituted phenylhemes, respectively. The addition of NADPH-P450 reductase to the H2O2-generated hHO-1-isoporphyrin complex produced alpha-biliverdin, confirming its role as a reaction intermediate. Identification of an isoporphyrin intermediate in the catalytic sequence of hHO-1, the first such intermediate observed in hemoprotein catalysis, completes our understanding of the critical first step of heme oxidation.

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.

Analysis and prediction of the alpha-function parameters used in cubic equations of state

DEFF Research Database (Denmark)

Privata, Romain; Viscontea, Maxime; Zazoua-Khames, Anis

2015-01-01

and compared regarding their ability to reproduce vapor pressure, heat of vaporization, liquid heat capacity, liquid density and second virial coefficient data. To reach this objective, extensive databanks of alpha function parameters were created. In particular, pitfalls of Twu-type alpha functions were...

A Tool for Predicting Regulatory Approval After Phase II Testing of New Oncology Compounds.

Science.gov (United States)

DiMasi, J A; Hermann, J C; Twyman, K; Kondru, R K; Stergiopoulos, S; Getz, K A; Rackoff, W

2015-11-01

We developed an algorithm (ANDI) for predicting regulatory marketing approval for new cancer drugs after phase II testing has been conducted, with the objective of providing a tool to improve drug portfolio decision-making. We examined 98 oncology drugs from the top 50 pharmaceutical companies (2006 sales) that first entered clinical development from 1999 to 2007, had been taken to at least phase II development, and had a known final outcome (research abandonment or regulatory marketing approval). Data on safety, efficacy, operational, market, and company characteristics were obtained from public sources. Logistic regression and machine-learning methods were used to provide an unbiased approach to assess overall predictability and to identify the most important individual predictors. We found that a simple four-factor model (activity, number of patients in the pivotal phase II trial, phase II duration, and a prevalence-related measure) had high sensitivity and specificity for predicting regulatory marketing approval. © 2015 American Society for Clinical Pharmacology and Therapeutics.

Interleukin-10 to tumor necrosis factor-alpha ratio is a predictive biomarker in nonalcoholic fatty liver disease: interleukin-10 to tumor necrosis factor-alpha ratio in steatohepatitis.

Science.gov (United States)

Hashem, Reem M; Mahmoud, Mona F; El-Moselhy, Mohamed A; Soliman, Hala M

2008-10-01

Fatty liver disease is commonly associated with diabetes mellitus (DM). Insulin resistance (IR) as an investigative biomarker is only concerned with fatty liver that results from DM type 2 associated with metabolic syndrome. Irrespective of IR, DM is generally characterized by overproduction of the proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha), whereas action of the latter is modulated by the anti-inflammatory cytokine interleukin-10 (IL-10). The aim of this study was to investigate the efficacy of using TNF-alpha alone or IL-10/TNF-alpha ratio compared to IR, as a promising biomarker for fatty liver assessment in DM. Furthermore, we hypothesized that using garlic as an immunomodulator may decrease TNF-alpha and increase IL-10 production to improve steatohepatitis. DM was induced metabolically by a high-fat diet to bring about IR, or chemically by alloxan, producing insulin deficiency, in male albino rats. Garlic powder was supplemented (15 mg/kg per day) for 3 weeks. Fatty liver was depicted histologically and biochemically (aspartic aminotransferase, alanine aminotransferase, HOMA-IR, TNF-alpha, IL-10, IL-10/TNF-alpha ratio). We found that, in contrast to obese rats, garlic decreased IL-10/TNF-alpha ratio, despite decreasing TNF-alpha in alloxan diabetic rats in agreement with the histology, which revealed more prominent improvement in the obese group. Moreover, the effect of garlic was not linked to improvement of IR in obese rats. We conclude that IL-10/TNF-alpha ratio may be considered as a convenient biomarker for investigation of fatty liver of different grades, apart from being associated with IR, and immunomodulation of this ratio in favor of increasing it may exert significant improvement.

Analytical prediction of the electromagnetic torques in single-phase and two-phase ac motors

Energy Technology Data Exchange (ETDEWEB)

Popescu, M.

2004-07-01

The single-phase and two-phase versions of AC motors can be modelled by means of the two-axis (d-q) theory with sufficient accuracy when the equivalent circuit parameters are correctly estimated. This work attempts to present a unified approach to the analytical prediction of the electromagnetic torque of these machines. Classical d-q axes formulation requires that the reference frame should be fixed on the frame where the asymmetries arise, i.e. the stator and rotor. The asynchronous torques that characterize the induction motors are modelled in a stationary reference frame, where the d-q axes coincide with the physical magnetic axes of the stator windings. For the permanent magnet motors, that may exhibit asymmetries on both stator and rotor, the proposed solution includes: a series of frame transformations, followed by symmetrical components decomposition. As in single-phase and two-phase systems the homopolar component is zero; each symmetrical component - negative and positive - is further analysed using d-q axes theory. The superposition principle is employed to consider the magnets and rotor cage effects. The developed models account for the most important asymmetries of the motor configuration. These are, from the stator point of view, different distribution, conductors' dimensions and number of effective turns, non-orthogonal magnetic axes windings and from the rotor point of view, asymmetrical rotor cage, variable reluctance, and permanent magnets effect. The time and space harmonics effect is ignored. Test data are compared with the computed data in order to observe how the simplifying assumptions affect the level of accuracy. The analytical prediction methods make possible torque computation according to the nature of the torque being computed, namely, induction, reluctance and excitation (permanent magnet). The results are available for quasi steady-state, steady-state (rated or synchronous speed) and dynamic analyses. All the developed

Structural details (kinks and non-alpha conformations) in transmembrane helices are intrahelically determined and can be predicted by sequence pattern descriptors.

Science.gov (United States)

Rigoutsos, Isidore; Riek, Peter; Graham, Robert M; Novotny, Jiri

2003-08-01

One of the promising methods of protein structure prediction involves the use of amino acid sequence-derived patterns. Here we report on the creation of non-degenerate motif descriptors derived through data mining of training sets of residues taken from the transmembrane-spanning segments of polytopic proteins. These residues correspond to short regions in which there is a deviation from the regular alpha-helical character (i.e. pi-helices, 3(10)-helices and kinks). A 'search engine' derived from these motif descriptors correctly identifies, and discriminates amongst instances of the above 'non-canonical' helical motifs contained in the SwissProt/TrEMBL database of protein primary structures. Our results suggest that deviations from alpha-helicity are encoded locally in sequence patterns only about 7-9 residues long and can be determined in silico directly from the amino acid sequence. Delineation of such variations in helical habit is critical to understanding the complex structure-function relationships of polytopic proteins and for drug discovery. The success of our current methodology foretells development of similar prediction tools capable of identifying other structural motifs from sequence alone. The method described here has been implemented and is available on the World Wide Web at http://cbcsrv.watson.ibm.com/Ttkw.html.

Alpha decay studies on Po isotopes using different versions of nuclear potentials

Energy Technology Data Exchange (ETDEWEB)

Santhosh, K.P.; Sukumaran, Indu [Kannur University, School of Pure and Applied Physics, Payyanur, Kerala (India)

2017-12-15

The alpha decays from {sup 186-224}Po isotopes have been studied using 25 different versions of nuclear potentials so as to select a suitable nuclear potential for alpha decay studies. The computed standard deviation of the calculated half-lives in comparison with the experimental data suggested that proximity 2003-I is the apt form of nuclear potential for alpha decay studies as it possesses the least standard deviation, σ = 0.620. Among the different proximity potentials, proximity 1966 (σ = 0.630) and proximity 1977 (σ = 0.636), are also found to work well in alpha decay studies with low deviation. Among other versions of nuclear potentials (other than proximity potentials), Bass 1980 is suggested to be a significant form of nuclear potential because of its good predictive power. However, while the other forms of potentials are able to reproduce the experimental data to some extent, these potentials cannot be considered as apposite potentials for alpha decay studies in their present form. Since the experimental correlation of the models is noticed to be satisfying, the alpha decay half-lives of certain Po isotopes that are not detected experimentally yet have been predicted. (orig.)

Using reweighting and free energy surface interpolation to predict solid-solid phase diagrams

Science.gov (United States)

Schieber, Natalie P.; Dybeck, Eric C.; Shirts, Michael R.

2018-04-01

Many physical properties of small organic molecules are dependent on the current crystal packing, or polymorph, of the material, including bioavailability of pharmaceuticals, optical properties of dyes, and charge transport properties of semiconductors. Predicting the most stable crystalline form at a given temperature and pressure requires determining the crystalline form with the lowest relative Gibbs free energy. Effective computational prediction of the most stable polymorph could save significant time and effort in the design of novel molecular crystalline solids or predict their behavior under new conditions. In this study, we introduce a new approach using multistate reweighting to address the problem of determining solid-solid phase diagrams and apply this approach to the phase diagram of solid benzene. For this approach, we perform sampling at a selection of temperature and pressure states in the region of interest. We use multistate reweighting methods to determine the reduced free energy differences between T and P states within a given polymorph and validate this phase diagram using several measures. The relative stability of the polymorphs at the sampled states can be successively interpolated from these points to create the phase diagram by combining these reduced free energy differences with a reference Gibbs free energy difference between polymorphs. The method also allows for straightforward estimation of uncertainties in the phase boundary. We also find that when properly implemented, multistate reweighting for phase diagram determination scales better with the size of the system than previously estimated.

General architecture of the alpha-helical globule.

Science.gov (United States)

Murzin, A G; Finkelstein, A V

1988-12-05

A model is presented for the arrangement of alpha-helices in globular proteins. In the model, helices are placed on certain ribs of "quasi-spherical" polyhedra. The polyhedra are chosen so as to allow the close packing of helices around a hydrophobic core and to stress the collective interactions of the individual helices. The model predicts a small set of stable architectures for alpha-helices in globular proteins and describes the geometries of the helix packings. Some of the predicted helix arrangements have already been observed in known protein structures; others are new. An analysis of the three-dimensional structures of all proteins for which co-ordinates are available shows that the model closely approximates the arrangements and packing of helices actually observed. The average deviations of the real helix axes from those in the model polyhedra is +/- 20 degrees in orientation and +/- 2 A in position (1 A = 0.1 nm). We also show that for proteins that are not homologous, but whose helix arrangements are described by the same polyhedron, the root-mean-square difference in the position of the C alpha atoms in the helices is 1.6 to 3.0 A.

Removal characteristics and kinetic analysis of an aerobic vapor-phase bioreactor for hydrophobic alpha-pinene.

Science.gov (United States)

Jiang, Yifeng; Li, Shanshan; Cheng, Zhuowei; Zhu, Runye; Chen, Jianmeng

2012-01-01

Biofiltration is considered an effective method to control volatile organic compounds (VOCs) pollution. This study was conducted to evaluate the potential use of a bacterial biofilter packed with wood chips and peat for the removal of hydrophobic alpha-pinene. When inoculated with two pure degraders and adapted activated sludge, a removal efficiency (RE) of more than 95% was achieved after a startup period of 11 days. The maximum elimination capacity (EC) of 50 g/(m3 x hr) with RE of 94% was obtained at empty bed retention time (EBRT) of 102 sec. When higher alpha-pinene concentrations and shorter EBRTs were applied, the REs and ECs decreased significantly due to mass-transfer and biological reaction limitations. As deduced from the experimental results, approximately 74% of alpha-pinene were completely mineralized by the consortiums and the biomass yield was 0.60 g biomass/g alpha-pinene. Sequence analysis of the selected bands excised from denaturing gradient gel electrophoresis revealed that the inoculated pure cultures could be present during the whole operation, and others were closely related to bacteria being able to degrade hydrocarbons. The kinetic results demonstrated that the whole biofiltration for alpha-pinene was diffusion-limit controlled owing to its hydrophobic characteristics. These findings indicated that this bacterial biofiltration is a promising technology for the remediation of hydrophobic industrial waste gases containing alpha-pinene.

Study of. cap alpha. -/sup 16/O scattering by orthogonality condition models

Energy Technology Data Exchange (ETDEWEB)

Breitschaft, A M; Canto, L F; Schechter, H

1983-06-01

The use of approximate microscopic theories in ..cap alpha..-/sup 16/O scattering is investigated. The Orthogonality Condition Model (OCM) with both the direct potential of the Resonating Group Method (RMG) and with an effective local potential, V sub(eff), derived from Kernels of Generator Coordinate Method (GCM) is employed to study collisions at CM energies up to 30 MeV, for all relevant partial waves. Although the predictions of the OCM are consistent with exact RGM results in both cases, the nuclear phase-shifts obtained with the effective potential are better. The presence of ambiguities in the derivation of V sub(eff) is noticed. The nature of such ambiguities is discussed.

A new phase of ThC at high pressure predicted from a first-principles study

Science.gov (United States)

Guo, Yongliang; Qiu, Wujie; Ke, Xuezhi; Huai, Ping; Cheng, Cheng; Han, Han; Ren, Cuilan; Zhu, Zhiyuan

2015-08-01

The phase transition of thorium monocarbide (ThC) at high pressure has been studied by means of density functional theory. Through structure search, a new phase with space group P 4 / nmm has been predicted. The calculated phonons demonstrate that this new phase and the previous B2 phase are dynamically stable as the external pressure is greater than 60 GPa and 120 GPa, respectively. The transformation from B1 to P 4 / nmm is predicted to be a first-order transition, while that from P 4 / nmm to B2 is found to be a second-order transition.

Sneutrino Inflation with $\\alpha$-attractors

CERN Document Server

Kallosh, Renata; Roest, Diederik; Wrase, Timm

2016-11-22

Sneutrino inflation employs the fermionic partners of the inflaton and stabilizer field as right-handed neutrinos to realize the seesaw mechanism for light neutrino masses. A crucial ingredient in existing constructions for sneutrino (multi-)natural inflation is an unbroken discrete shift symmetry. We demonstrate that a similar construction applies to $\\alpha$-attractor models. In this case the hyperbolic geometry protects the neutrino Yukawa couplings to the inflaton field, and the masses of leptons and Higgs fields, from blowing up when the inflaton is super-Planckian. We find that the predictions for $n_s$ and $r$ for $\\alpha$-attractor cosmological models, compatible with the current cosmological data, are preserved in the presence of the neutrino sector.

Recurrent mass ejections observed in H-alpha and CIV

International Nuclear Information System (INIS)

Schmieder, B.; Simon, G.

1984-01-01

Time sequences of recurrent mass ejections have been observed during a coordinated SMY program (Sept. 1, 1980 - Sept. 23, 1980 - Oct. 2, 1980). Comparison of the temporal evolution of H-alpha and CIV brightnesses shows a weak phase lag between H-alpha and CIV maxima, in the case of homologous flares, with CIV brightness maxima preceding H-alpha maxima. The analysis of the variation of the ejection velocities is expected to lead to the determination of an energy balance. Such recurrent ejections could be due to periodic energy storage and periodic reorganization of magnetic field as envisaged to occur for flares, but at lower energy levels

Antibody Probes to Estrogen Receptor-Alpha Transcript-Specific Upstream Peptides: Alternate ER-Alpha Promoter Use and Breast Cancer Etiology/Outcome

National Research Council Canada - National Science Library

Pentecost, Brian

2002-01-01

Positive Estrogen Receptor alpha (ER) status correlates with a reduced incidence of breast cancer recurrence in the first years after resection of tumors, and predicts a favorable response to adjuvant anti-estrogens...

Alpha-Driven MHD and MHD-Induced Alpha Loss in TFTR DT Experiments

Science.gov (United States)

Chang, Zuoyang

1996-11-01

Theoretical calculation and numerical simulation indicate that there can be interesting interactions between alpha particles and MHD activity which can adversely affect the performance of a tokamak reactor (e.g., ITER). These interactions include alpha-driven MHD, like the toroidicity-induced-Alfven-eigenmode (TAE) and MHD induced alpha particle losses or redistribution. Both phenomena have been observed in recent TFTR DT experiments. Weak alpha-driven TAE activity was observed in a NBI-heated DT experiment characterized by high q0 ( >= 2) and low core magnetic shear. The TAE mode appears at ~30-100 ms after the neutral beam turning off approximately as predicted by theory. The mode has an amplitude measured by magnetic coils at the edge tildeB_p ~1 mG, frequency ~150-190 kHz and toroidal mode number ~2-3. It lasts only ~ 30-70 ms and has been seen only in DT discharges with fusion power level about 1.5-2.0 MW. Numerical calculation using NOVA-K code shows that this type of plasma has a big TAE gap. The calculated TAE frequency and mode number are close to the observation. (2) KBM-induced alpha particle loss^1. In some high-β, high fusion power DT experiments, enhanced alpha particle losses were observed to be correlated to the high frequency MHD modes with f ~100-200 kHz (the TAE frequency would be two-times higher) and n ~5-10. These modes are localized around the peak plasma pressure gradient and have ballooning characteristics. Alpha loss increases by 30-100% during the modes. Particle orbit simulations show the added loss results from wave-particle resonance. Linear instability analysis indicates that the plasma is unstable to the kinetic MHD ballooning modes (KBM) driven primarily by strong local pressure gradients. ----------------- ^1Z. Chang, et al, Phys. Rev. Lett. 76 (1996) 1071. In collaberation with R. Nazikian, G.-Y. Fu, S. Batha, R. Budny, L. Chen, D. Darrow, E. Fredrickson, R. Majeski, D. Mansfield, K. McGuire, G. Rewoldt, G. Taylor, R. White, K

Phase transformation and microstructural changes during ageing process of an Ag-Pd-Cu-Au alloy

Energy Technology Data Exchange (ETDEWEB)

Yu, Chin-Ho; Park, Mi-Gyoung; Kwon, Yong Hoon; Seol, Hyo-Joung [Department of Dental Materials, School of Dentistry and Medical Research Institute, Pusan National University, 1-10 Ami-dong, Seo-gu, Pusan 602-739 (Korea, Republic of); Kim, Hyung-Il [Department of Dental Materials, School of Dentistry and Medical Research Institute, Pusan National University, 1-10 Ami-dong, Seo-gu, Pusan 602-739 (Korea, Republic of)], E-mail: hilkim@pusan.ac.kr

2008-07-28

Age-hardening behaviour and the related phase transformation and microstructural changes during isothermal ageing process were studied to elucidate the age-hardening mechanism of an Ag-based dental casting alloy composed of Ag-Pd-Cu-Au-Zn, Ir and In by means of hardness test, X-ray diffraction (XRD), scanning electron microscopic (SEM) observations and energy dispersive spectroscopic microanalysis (EDS). In the hardness test at 350 and 400 deg. C, the hardness of the solution-treated specimen began to increase and reached a maximum value with increasing ageing time, and subsequently the hardness decreased gradually. By considering XRD results and SEM observations together, the solution-treated specimen consisted of three phases, the Ag-rich {alpha}{sub 1} phase as a matrix, the Cu-Pd {alpha}{sub 2} phase and the CuPd {beta} phase with a CsCl-type as particle-like structures. By ageing the solution-treated specimen, the Ag-rich {alpha}{sub 1} and Cu-Pd {alpha}{sub 2} phases were transformed into the Ag-rich {alpha}{sup '}{sub 1} and Cu{sub 3}Pd {alpha}{sup '}{sub 2} phases, respectively. The CuPd {beta} phase with a CsCl-type was not changed apparently during the ageing process. From the results of the hardness test, XRD study, SEM observations and EDS analysis, it could be derived that the hardness increased by the diffusion and precipitation of the Cu-rich phase from the Ag-rich matrix during the early stage of phase transformation of {alpha}{sub 1} into {alpha}{sup '}{sub 1} and that the progress of coarsening of the Cu-rich precipitates with an entanglement structure caused the hardness decrease during the later stage of phase transformation of {alpha}{sub 1} into {alpha}{sup '}{sub 1}. The particle-like structures composed of the Cu-Pd {alpha}{sub 2} and the CuPd {beta} phase with a CsCl-type contributed little to the hardness increase which occurred in the early stage of aging process.

Non-resonant triple alpha reaction rate at low temperature

Energy Technology Data Exchange (ETDEWEB)

Itoh, T.; Tamii, A.; Aoi, N.; Fujita, H.; Hashimoto, T.; Miki, K.; Ogata, K. [Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Carter, J.; Donaldson, L.; Sideras-Haddad, E. [Schools of Physics, University of Witwatersrand, Johannesburg 2050 (South Africa); Furuno, T.; Kawabata, T. [Departments of Physics, Kyoto University, Sakyo, Kyoto, 606-8502 (Japan); Kamimura, M. [RIKEN Nishina Center, Wako, Saitama, 351-0198 (Japan); Nemulodi, F.; Neveling, R.; Smit, F. D.; Swarts, C. [iThemba Laboratory for Accelerator Based Sciences Somerset, West, 7129 (South Africa)

2014-05-02

Our experimental goal is to study the non-resonant triple alpha reaction rate at low temperture (T < 10{sup 8} K). The {sup 13}C(p,d) reaction at 66 MeV has been used to probe the alpha-unbound continuum state in {sup 12}C just below the 2{sup nd} 0{sup +} state at 7.65 MeV. The transition strength to the continuum state is predicted to be sensitive to the non-resonant triple alpha reaction rate. The experiment has been performed at iThemba LABS. We report the present status of the experiment.

Phase Transition Couplings in the Higgsed Monopole Model

CERN Document Server

Laperashvili, L V

1999-01-01

Using a one-loop approximation for the effective potential in the Higgs model of electrodynamics for a charged scalar field, we argue for the existence of a triple point for the renormalized (running) values of the selfinteraction beta-function as a typical quantity we estimate that the one-loop approximation is valid with accuracy of deviations not more than 30% in the region of the parameters: $0.2 \\stackrel{<}{\\sim}{\\large \\alpha, \\tilde{\\alpha}} corresponds to the above-mentioned region of $\\alpha, \\tilde \\alpha$. Under the point of view that the Higgs particle is a monopole with a magnetic charge g, the obtained electric fine structure constant turns out to be to the $\\alpha_{crit}^{lat}\\approx{0.20}$ which in a U(1) lattice gauge theory corresponds to the phase transition between the "Coulomb" and confinement phases. Such a result is very encouraging for the idea of an approximate "universality" (regularization independence) of gauge couplings at the phase transition point. This idea was suggested by...

A Simplified Micromechanical Modeling Approach to Predict the Tensile Flow Curve Behavior of Dual-Phase Steels

Science.gov (United States)

Nanda, Tarun; Kumar, B. Ravi; Singh, Vishal

2017-11-01

Micromechanical modeling is used to predict material's tensile flow curve behavior based on microstructural characteristics. This research develops a simplified micromechanical modeling approach for predicting flow curve behavior of dual-phase steels. The existing literature reports on two broad approaches for determining tensile flow curve of these steels. The modeling approach developed in this work attempts to overcome specific limitations of the existing two approaches. This approach combines dislocation-based strain-hardening method with rule of mixtures. In the first step of modeling, `dislocation-based strain-hardening method' was employed to predict tensile behavior of individual phases of ferrite and martensite. In the second step, the individual flow curves were combined using `rule of mixtures,' to obtain the composite dual-phase flow behavior. To check accuracy of proposed model, four distinct dual-phase microstructures comprising of different ferrite grain size, martensite fraction, and carbon content in martensite were processed by annealing experiments. The true stress-strain curves for various microstructures were predicted with the newly developed micromechanical model. The results of micromechanical model matched closely with those of actual tensile tests. Thus, this micromechanical modeling approach can be used to predict and optimize the tensile flow behavior of dual-phase steels.

Simulation of Alpha Particles in Rotating Plasma Interacting with a Stationary Ripple

International Nuclear Information System (INIS)

Fetterman, Abraham J.; Fisch, Nathaniel J.

2011-01-01

Superthermal ExB rotation can provide magnetohydrodynamic (MHD) stability and enhanced confinement to axisymmetric mirrors. However, the rotation speed has been limited by phenomena at end electrodes. A new prediction is that rotation might instead be produced using a magnetic ripple and alpha particle kinetic energy, in an extension of the alpha channeling concept. The interaction of alpha particles with the ripple results in visually interesting and practically useful orbits.

Development of alpha radioactivity measurement using ionized air transportation technology

International Nuclear Information System (INIS)

Kanemoto, Shigeru; Naito, Susumu; Sano, Akira; Sato, Mitsuyoshi; Fukumoto, Masahiko; Miyamoto, Yasuaki; Nanbu, Kenichi; Takahashi, Hiroyuki

2005-01-01

Alpha radioactivity Measurement using ionized Air Transportation technology (AMAT) is developed to measure alpha contaminated wastes with large and complex surfaces. An outline of this project was described in this text. A major problem of AMAT technology is that the theoretical relation between alpha radioactivity and observed ion current is unclear because of the complicated behavior of ionized air molecules. An ion current prediction model covering from ionization of air molecules to ion detection was developed based on atmospheric electrodynamics. This model was described in this text, too. (author)

Manifestation of the structure of heavy nuclei in their alpha decays

Energy Technology Data Exchange (ETDEWEB)

Adamian, G. G., E-mail: adamian@theor.jinr.ru; Antonenko, N. V.; Bezbakh, A. N.; Malov, L. A. [Joint Institute for Nuclear Research (Russian Federation)

2016-11-15

Low-lying one- and two-quasiparticle states of heavy nuclei are predicted. Alpha-decay chains, including those that proceed through isomeric states, are examined on the basis of the predicted properties of superheavy nuclei.

Predictions for the Dirac C P -violating phase from sum rules

Science.gov (United States)

Delgadillo, Luis A.; Everett, Lisa L.; Ramos, Raymundo; Stuart, Alexander J.

2018-05-01

We explore the implications of recent results relating the Dirac C P -violating phase to predicted and measured leptonic mixing angles within a standard set of theoretical scenarios in which charged lepton corrections are responsible for generating a nonzero value of the reactor mixing angle. We employ a full set of leptonic sum rules as required by the unitarity of the lepton mixing matrix, which can be reduced to predictions for the observable mixing angles and the Dirac C P -violating phase in terms of model parameters. These sum rules are investigated within a given set of theoretical scenarios for the neutrino sector diagonalization matrix for several known classes of charged lepton corrections. The results provide explicit maps of the allowed model parameter space within each given scenario and assumed form of charged lepton perturbations.

Prediction of Active Site and Distal Residues in E. coli DNA Polymerase III alpha Polymerase Activity.

Science.gov (United States)

Parasuram, Ramya; Coulther, Timothy A; Hollander, Judith M; Keston-Smith, Elise; Ondrechen, Mary Jo; Beuning, Penny J

2018-02-20

The process of DNA replication is carried out with high efficiency and accuracy by DNA polymerases. The replicative polymerase in E. coli is DNA Pol III, which is a complex of 10 different subunits that coordinates simultaneous replication on the leading and lagging strands. The 1160-residue Pol III alpha subunit is responsible for the polymerase activity and copies DNA accurately, making one error per 10 5 nucleotide incorporations. The goal of this research is to determine the residues that contribute to the activity of the polymerase subunit. Homology modeling and the computational methods of THEMATICS and POOL were used to predict functionally important amino acid residues through their computed chemical properties. Site-directed mutagenesis and biochemical assays were used to validate these predictions. Primer extension, steady-state single-nucleotide incorporation kinetics, and thermal denaturation assays were performed to understand the contribution of these residues to the function of the polymerase. This work shows that the top 15 residues predicted by POOL, a set that includes the three previously known catalytic aspartate residues, seven remote residues, plus five previously unexplored first-layer residues, are important for function. Six previously unidentified residues, R362, D405, K553, Y686, E688, and H760, are each essential to Pol III activity; three additional residues, Y340, R390, and K758, play important roles in activity.

High performance predictive current control of a three phase VSI: An ...

Indian Academy of Sciences (India)

... current control of a three phase VSI: An experimental assessment ... Voltage source inverter; two level inverter; predictive current control; weighting factor ... Conventionally, for reference current tracking control in a two level VSI, the objective ...

Prediction of clearance, volume of distribution and half-life by allometric scaling and by use of plasma concentrations predicted from pharmacokinetic constants: a comparative study.

Science.gov (United States)

Mahmood, I

1999-08-01

Pharmacokinetic parameters (clearance, CL, volume of distribution in the central compartment, VdC, and elimination half-life, t1/2beta) predicted by an empirical allometric approach have been compared with parameters predicted from plasma concentrations calculated by use of the pharmacokinetic constants A, B, alpha and beta, where A and B are the intercepts on the Y axis of the plot of plasma concentration against time and alpha and beta are the rate constants, both pairs of constants being for the distribution and elimination phases, respectively. The pharmacokinetic parameters of cefpiramide, actisomide, troglitazone, procaterol, moxalactam and ciprofloxacin were scaled from animal data obtained from the literature. Three methods were used to generate plots for the prediction of clearance in man: dependence of clearance on body weight (simple allometric equation); dependence of the product of clearance and maximum life-span potential (MLP) on body weight; and dependence of the product of clearance and brain weight on body weight. Plasma concentrations of the drugs were predicted in man by use of A, B, alpha and beta obtained from animal data. The predicted plasma concentrations were then used to calculate CL, VdC and t1/2beta. The pharmacokinetic parameters predicted by use of both approaches were compared with measured values. The results indicate that simple allometry did not predict clearance satisfactorily for actisomide, troglitazone, procaterol and ciprofloxacin. Use of MLP or the product of clearance and brain weight improved the prediction of clearance for these four drugs. Except for troglitazone, VdC and t1/2beta predicted for man by use of the allometric approach were comparable with measured values for the drugs studied. CL, VdC and t1/2beta predicted by use of pharmacokinetic constants were comparable with values predicted by simple allometry. Thus, if simple allometry failed to predict clearance of a drug, so did the pharmacokinetic constant

Distribution of alpha3, alpha5 and alpha(v) integrin subunits in mature and immature human oocytes.

Science.gov (United States)

Capmany, G; Mart, M; Santaló, J; Bolton, V N

1998-10-01

The distribution of three integrin subunits, alpha3, alpha5 and alpha(v), in immature and mature human oocytes has been examined using immunofluorescence and confocal microscopy. The results demonstrate that both alpha5 and alpha(v) are present at the germinal vesicle stage, while alpha3 was only detected in oocytes after germinal vesicle breakdown, in metaphase I and II stage oocytes. The cortical concentration of integrin subunits alpha3 and alpha5 is consistent with their localization in the oolemma. In contrast, the homogeneous distribution of alpha(v) throughout the oocyte suggests the existence of cytoplasmic reservoirs of this protein in the oocyte.

A method to reproduce alpha-particle spectra measured with semiconductor detectors.

Science.gov (United States)

Timón, A Fernández; Vargas, M Jurado; Sánchez, A Martín

2010-01-01

A method is proposed to reproduce alpha-particle spectra measured with silicon detectors, combining analytical and computer simulation techniques. The procedure includes the use of the Monte Carlo method to simulate the tracks of alpha-particles within the source and in the detector entrance window. The alpha-particle spectrum is finally obtained by the convolution of this simulated distribution and the theoretical distributions representing the contributions of the alpha-particle spectrometer to the spectrum. Experimental spectra from (233)U and (241)Am sources were compared with the predictions given by the proposed procedure, showing good agreement. The proposed method can be an important aid for the analysis and deconvolution of complex alpha-particle spectra. Copyright 2009 Elsevier Ltd. All rights reserved.

Predicting Anthracycline Benefit

DEFF Research Database (Denmark)

Bartlett, John M S; McConkey, Christopher C; Munro, Alison F

2015-01-01

PURPOSE: Evidence supporting the clinical utility of predictive biomarkers of anthracycline activity is weak, with a recent meta-analysis failing to provide strong evidence for either HER2 or TOP2A. Having previously shown that duplication of chromosome 17 pericentromeric alpha satellite as measu......PURPOSE: Evidence supporting the clinical utility of predictive biomarkers of anthracycline activity is weak, with a recent meta-analysis failing to provide strong evidence for either HER2 or TOP2A. Having previously shown that duplication of chromosome 17 pericentromeric alpha satellite...

Application of neural networks to prediction of phase transport characteristics in high-pressure two-phase turbulent bubbly flows

International Nuclear Information System (INIS)

Yang, A.-S.; Kuo, T.-C.; Ling, P.-H.

2003-01-01

The phase transport phenomenon of the high-pressure two-phase turbulent bubbly flow involves complicated interfacial interactions of the mass, momentum, and energy transfer processes between phases, revealing that an enormous effort is required in characterizing the liquid-gas flow behavior. Nonetheless, the instantaneous information of bubbly flow properties is often desired for many industrial applications. This investigation aims to demonstrate the successful use of neural networks in the real-time determination of two-phase flow properties at elevated pressures. Three back-propagation neural networks, trained with the simulation results of a comprehensive theoretical model, are established to predict the transport characteristics (specifically the distributions of void-fraction and axial liquid-gas velocities) of upward turbulent bubbly pipe flows at pressures covering 3.5-7.0 MPa. Comparisons of the predictions with the test target vectors indicate that the averaged root-mean-squared (RMS) error for each one of three back-propagation neural networks is within 4.59%. In addition, this study appraises the effects of different network parameters, including the number of hidden nodes, the type of transfer function, the number of training pairs, the learning rate-increasing ratio, the learning rate-decreasing ratio, and the momentum value, on the training quality of neural networks.

Prestimulus alpha-band power biases visual discrimination confidence, but not accuracy.

Science.gov (United States)

Samaha, Jason; Iemi, Luca; Postle, Bradley R

2017-09-01

The magnitude of power in the alpha-band (8-13Hz) of the electroencephalogram (EEG) prior to the onset of a near threshold visual stimulus predicts performance. Together with other findings, this has been interpreted as evidence that alpha-band dynamics reflect cortical excitability. We reasoned, however, that non-specific changes in excitability would be expected to influence signal and noise in the same way, leaving actual discriminability unchanged. Indeed, using a two-choice orientation discrimination task, we found that discrimination accuracy was unaffected by fluctuations in prestimulus alpha power. Decision confidence, on the other hand, was strongly negatively correlated with prestimulus alpha power. This finding constitutes a clear dissociation between objective and subjective measures of visual perception as a function of prestimulus cortical excitability. This dissociation is predicted by a model where the balance of evidence supporting each choice drives objective performance but only the magnitude of evidence supporting the selected choice drives subjective reports, suggesting that human perceptual confidence can be suboptimal with respect to tracking objective accuracy. Copyright © 2017 Elsevier Inc. All rights reserved.

Predicting death from tumour necrosis factor-alpha and interleukin-6 in 80-year-old people

DEFF Research Database (Denmark)

Bruunsgaard, H; Ladelund, S; Pedersen, A N

2003-01-01

Ageing is associated with low-grade inflammation and markers such as IL-6 possess prognostic value. Tumour necrosis-alpha (TNF-alpha) initiates the inflammatory cascade and has been linked to several age-associated disorders. It remains, however, unknown if TNF-alpha is associated with mortality...... in old populations. The aim of the present study was to investigate if serum levels of TNF-alpha were associated with all-cause mortality independently of interleukin (IL)-6 in a prospective study of 333 relatively healthy 80-year-old people. A Cox regression model was used to explore effects of TNF......% of the variability in IL-6 and effects of the two cytokines were independent of each other as well as of other traditional risk factors for death [smoking, blood pressure, physical exercise, total cholesterol, co-morbidity, body mass index (BMI) and intake of anti-inflammatory drugs]. These findings indicate...

Predicting death from tumour necrosis factor-alpha and interleukin-6 in 80-year-old people

DEFF Research Database (Denmark)

Bruunsgaard, H.; Ladelund, S.; Pedersen, Agnes Nadelmann

2003-01-01

Ageing is associated with low-grade inflammation and markers such as IL-6 possess prognostic value. Tumour necrosis-alpha (TNF-alpha ) initiates the inflammatory cascade and has been linked to several age-associated disorders. It remains, however, unknown if TNF-alpha is associated with mortality...... in old populations. The aim of the present study was to investigate if serum levels of TNF-alpha were associated with all-cause mortality independently of interleukin (IL)-6 in a prospective study of 333 relatively healthy 80-year-old people. A Cox regression model was used to explore effects of TNF......% of the variability in IL-6 and effects of the two cytokines were independent of each other as well as of other traditional risk factors for death [smoking, blood pressure, physical exercise, total cholesterol, co-morbidity, body mass index (BMI) and intake of anti-inflammatory drugs]. These findings indicate...

Penetration of HEPA filters by alpha recoil aerosols

International Nuclear Information System (INIS)

McDowell, W.J.; Seeley, F.G.; Ryan, M.T.

1976-01-01

The self-scattering of alpha-active substances has long been recognized and is attributed to expulsion of aggregates of atoms from the surface of alpha-active materials by alpha emission recoil energy, and perhaps to further propulsion of these aggregates by subsequent alpha recoils. Workers at the University of Lowell recently predicted that this phenomenon might affect the retention of alpha-active particulate matter by HEPA filters, and found support in experiments with 212 Pb. Tests at Oak Ridge National Laboratory have confirmed that alpha-emitting particulate matter does penetrate high-efficiency filter media, such as that used in HEPA filters, much more effectively than do non-radioactive or beta-gamma active aerosols. Filter retention efficiencies drastically lower than the 99.9 percent quoted for ordinary particulate matter were observed with 212 Pb, 253 Es, and 238 Pu sources, indicating that the phenomenon is common to all of these and probably to all alpha-emitting materials of appropriate half-life. Results with controlled air-flow through filters in series are consistent with the picture of small particles dislodged from the ''massive'' surface of an alpha-active material, and then repeatedly dislodged from positions on the filter fibers by subsequent alpha recoils. The process shows only a small dependence on the physical form of the source material. Oxide dust, nitrate salt, and plated metal all seem to generate the recoil particles effectively. The amount penetrating a series of filters depends on the total amount of activity in the source material, its specific activity, and the length of time of air flow

Application of Bayesian neural network modeling to characterize the interrelationship between microstructure and mechanical property in alpha+beta-titanium alloys

Science.gov (United States)

Koduri, Santhosh K.

-mentioned quantified microstructural information, composition and mechanical properties. The mechanical properties predicted in this study are tensile properties and fracture toughness. Based on the controlled virtual experiments conducted using neural networks on alpha+beta processed alloys suggested important microstructural features that will affect tensile properties are size of the equiaxed alpha grain and volume fraction of equiaxed alpha. The controlled virtual experiments on beta heat-treated alloys suggested important microstructural features such as width of the alpha lamellae, alpha colony size and prior beta grain size have negative influence on tensile properties. The virtual experiments conducted on alloys which are processed in the alpha+beta phase field suggested that the size of the equiaxed alpha is an important variable which increases the fracture toughness. In beta-processed alloys, important microstructural features such as size of the alpha colony decrease the fracture toughness while width of the alpha lamellae and prior beta grain size increase the fracture toughness. The alloying elements such Al, O and Fe improve the yield strength of both alpha+beta processed and beta processed alpha+beta titanium alloys. The O and Al have negative influence on fracture toughness while Fe has positive influence on fracture toughness. The examination of the region beneath the fracture surface of alpha+beta processed alloy suggested occurrence of the microcracks within the equiaxed alpha particle clusters. The frequency of occurrence of the microcracks is increased when two neighboring equiaxed alpha grains have common or near common basal plane. The detailed dislocation analysis on regions near the microcrack indicated presence of extensive basal slip.

Supramodal Theta, Gamma, and Sustained Fields Predict Modality-specific Modulations of Alpha and Beta Oscillations during Visual and Tactile Working Memory.

Science.gov (United States)

van Ede, Freek; Jensen, Ole; Maris, Eric

2017-08-01

Flexible control over currently relevant sensory representations is an essential feature of primate cognition. We investigated the neurophysiological bases of such flexible control in humans during an intermodal working memory task in which participants retained visual or tactile sequences. Using magnetoencephalography, we first show that working memory retention engages early visual and somatosensory areas, as reflected in the sustained load-dependent suppression of alpha and beta oscillations. Next, we identify three components that are also load dependent but modality independent: medial prefrontal theta synchronization, frontoparietal gamma synchronization, and sustained parietal event-related fields. Critically, these domain-general components predict (across trials and within load conditions) the modality-specific suppression of alpha and beta oscillations, with largely unique contributions per component. Thus, working memory engages multiple complementary frontoparietal components that have discernible neuronal dynamics and that flexibly modulate retention-related activity in sensory areas in a manner that tracks the current contents of working memory.

Behavior of the antiferromagnetic phase transition near the fermion condensation quantum phase transition in YbRh{sub 2}Si{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Shaginyan, V.R., E-mail: vrshag@thd.pnpi.spb.r [Petersburg Nuclear Physics Institute, RAS, Gatchina 188300 (Russian Federation); Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Amusia, M.Ya. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Popov, K.G. [Komi Science Center, Ural Division, RAS, Syktyvkar 167982 (Russian Federation)

2010-01-11

Low-temperature specific-heat measurements on YbRh{sub 2}Si{sub 2} at the second order antiferromagnetic (AF) phase transition reveal a sharp peak at T{sub N}=72 mK. The corresponding critical exponent alpha turns out to be alpha=0.38, which differs significantly from that obtained within the framework of the fluctuation theory of second order phase transitions based on the scale invariance, where alphaapprox =0.1. We show that under the application of magnetic field the curve of the second order AF phase transitions passes into a curve of the first order ones at the tricritical point leading to a violation of the critical universality of the fluctuation theory. This change of the phase transition is generated by the fermion condensation quantum phase transition. Near the tricritical point the Landau theory of second order phase transitions is applicable and gives alphaapprox =1/2. We demonstrate that this value of alpha is in good agreement with the specific-heat measurements.

Use of isoconcentrational phase diagrams for prediction of amorphization of binary systems

International Nuclear Information System (INIS)

Lazarev, A.I.; Belashchenko, D.K.

1992-01-01

Based on the application of isoconcentrational diagrams of phase equilibria of liquid with solid solutions of various crystal structures the thermodynamic method was considered for prediction of concentration ranges of amorphization in binary systems.To confirm the applicability of the thermodynamic criterion in practice caclulations of phase diagrams were accomplished for complex binary eutectic systems (Hf-Be, Zr-Be) with the known concentration ranges of amorphization

Phase-field simulation of nucleation and growth of M{sub 23}C{sub 6} carbide and ferromagnetic phases during creep deformation in Type 304 steel

Energy Technology Data Exchange (ETDEWEB)

Tsukada, Yuhki, E-mail: tsukada@silky.numse.nagoya-u.ac.j [Department of Materials, Physics and Energy Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Shiraki, Atsuhiro; Murata, Yoshinori [Department of Materials, Physics and Energy Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Takaya, Shigeru [Japan Atomic Energy Agency, 4002 Narita-cho, O-arai-machi, Higashi-ibaraki-gun, Ibaraki 311-1393 (Japan); Koyama, Toshiyuki [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Morinaga, Masahiko [Department of Materials, Physics and Energy Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

2010-06-15

A phase-field method was applied to the simulation of simultaneous nucleation and growth of both M{sub 23}C{sub 6} carbide and ferromagnetic {alpha} phases during the creep process in Type 304 steel. Nucleation events of these product phases were explicitly introduced through a probabilistic Poisson seeding process based on local nucleation rates that were calculated as a function of local concentration. The defect energy of the creep dislocations near the carbides, which increases during creep, was integrated into the nucleation driving force for the {alpha} phase. The simulation used in this study accurately reproduced changes in the amounts of the precipitated phases as a function of creep time. Furthermore, we examine the effect of the dislocation density on precipitation of the {alpha} phase, and show that the phase-field method is useful for examining the stochastic and kinetic phenomenon of phase transformation.

Resting state glutamate predicts elevated pre-stimulus alpha during self-relatedness: A combined EEG-MRS study on "rest-self overlap".

Science.gov (United States)

Bai, Yu; Nakao, Takashi; Xu, Jiameng; Qin, Pengmin; Chaves, Pedro; Heinzel, Alexander; Duncan, Niall; Lane, Timothy; Yen, Nai-Shing; Tsai, Shang-Yueh; Northoff, Georg

2016-01-01

Recent studies have demonstrated neural overlap between resting state activity and self-referential processing. This "rest-self" overlap occurs especially in anterior cortical midline structures like the perigenual anterior cingulate cortex (PACC). However, the exact neurotemporal and biochemical mechanisms remain to be identified. Therefore, we conducted a combined electroencephalography (EEG)-magnetic resonance spectroscopy (MRS) study. EEG focused on pre-stimulus (e.g., prior to stimulus presentation or perception) power changes to assess the degree to which those changes can predict subjects' perception (and judgment) of subsequent stimuli as high or low self-related. MRS measured resting state concentration of glutamate, focusing on PACC. High pre-stimulus (e.g., prior to stimulus presentation or perception) alpha power significantly correlated with both perception of stimuli judged to be highly self-related and with resting state glutamate concentrations in the PACC. In sum, our results show (i) pre-stimulus (e.g., prior to stimulus presentation or perception) alpha power and resting state glutamate concentration to mediate rest-self overlap that (ii) dispose or incline subjects to assign high degrees of self-relatedness to perceptual stimuli.

The determination of $\\alpha_s$ by the ALPHA collaboration

CERN Document Server

Bruno, Mattia

2016-01-01

We review the ALPHA collaboration strategy for obtaining the QCD coupling at high scale. In the three-flavor effective theory it avoids the use of perturbation theory at $\\alpha > 0.2$ and at the same time has the physical scales small compared to the cutoff $1/a$ in all stages of the computation. The result $\\Lambda_\\overline{MS}^{(3)}=332(14)$~MeV is translated to $\\alpha_\\overline{MS}(m_Z)=0.1179(10)(2)$ by use of (high order) perturbative relations between the effective theory couplings at the charm and beauty quark "thresholds". The error of this perturbative step is discussed and estimated as $0.0002$.

Neuronal oscillations with non-sinusoidal morphology produce spurious phase-to-amplitude coupling and directionality.

Directory of Open Access Journals (Sweden)

Diego Lozano-Soldevilla

2016-08-01

Full Text Available Neuronal oscillations support cognitive processing. Modern views suggest that neuronal oscillations do not only reflect coordinated activity in spatially distributed networks, but also that there is interaction between the oscillations at different frequencies. For example, invasive recordings in animals and humans have found that the amplitude of fast oscillations (> 40 Hz occur non-uniformly within the phase of slower oscillations, forming the so-called cross-frequency coupling (CFC. However, the CFC patterns be influenced by features in the signal that do not relate to underlying physiological interactions. For example, CFC estimates may be sensitive to spectral correlations due to non-sinusoidal properties of the alpha band wave morphology. To investigate this issue, we performed CFC analysis using experimental and synthetic data. The former consisted in a double-blind magnetoencephalography pharmacological study in which participants received either placebo, 0.5 mg or 1.5 mg of lorazepam (LZP; GABAergic enhancer in different experimental sessions. By recording oscillatory brain activity with during rest and working memory (WM, we were able to demonstrate that posterior alpha (8 – 12 Hz phase was coupled to beta-low gamma band (20 – 45 Hz amplitude envelope during all sessions. Importantly, bicoherence values around the harmonics of the alpha frequency were similar both in magnitude and topographic distribution to the cross-frequency coherence (CFCoh values observed in the alpha-phase to beta-low gamma coupling. In addition, despite the large CFCoh we found no significant cross-frequency directionality (CFD. Critically, simulations demonstrated that a sizable part of our empirical CFCoh between alpha and beta-low gamma coupling and the lack of CFD could be explained by two-three harmonics aligned in zero phase-lag produced by the physiologically characteristic alpha asymmetry in the amplitude of the peaks relative to the troughs

Plasma alpha-1-acid glycoprotein as a potential predictive biomarker for non-haematological adverse events of docetaxel in breast cancer patients.

Science.gov (United States)

Jabir, Rafid Salim; Ho, Gwo Fuang; Annuar, Muhammad Azrif Bin Ahmad; Stanslas, Johnson

2018-03-01

Rash and oral mucositis are major non-haematological adverse events (AEs) of docetaxel, in addition to fatigue, nausea, vomiting and diarrhoea, which restrict the use of the drug in cancer therapy. Alpha-1-acid glycoprotein (AAG) is an acute phase reactant glycoprotein and is a primary carrier of docetaxel in the blood. Docetaxel has extensive binding (>98%) to plasma proteins such as AAG, lipoproteins and albumin. To study the association between plasma AAG level and non-haematological AEs of docetaxel in Malaysian breast cancer patients of three major ethnic groups (Malays, Chinese and Indians). One hundred and twenty Malaysian breast cancer patients receiving docetaxel as single agent chemotherapy were investigated for AAG plasma level using enzyme-linked immunosorbent assay technique. Toxicity assessment was determined using Common Terminology Criteria of Adverse Events v4.0. The association between AAG and toxicity were then established. There was interethnic variation of plasma AAG level; it was 182 ± 85 mg/dl in Chinese, 237 ± 94 mg/dl in Malays and 240 ± 83 mg/dl in Indians. It was found that low plasma levels of AAG were significantly associated with oral mucositis and rash. This study proposes plasma AAG as a potential predictive biomarker of docetaxel non-haematological AEs namely oral mucositis and rash.

Serum Adiponectin, Vitamin D, and Alpha-Fetoprotein in Children with Chronic Hepatitis C: Can They Predict Treatment Response?

Science.gov (United States)

Khedr, Mohamed Ahmed; Sira, Ahmad Mohamed; Saber, Magdy Anwar; Raia, Gamal Yousef

2015-01-01

Background & Aims. The currently available treatment for chronic hepatitis C (CHC) in children is costly and with much toxicity. So, predicting the likelihood of response before starting therapy is important. Methods. Serum adiponectin, vitamin D, and alpha-fetoprotein (AFP) were measured before starting pegylated-interferon/ribavirin therapy for 50 children with CHC. Another 21 healthy children were recruited as controls. Results. Serum adiponectin, vitamin D, and AFP were higher in the CHC group than healthy controls (p < 0.0001, p = 0.071, and p = 0.87, resp.). In univariate analysis, serum adiponectin was significantly higher in responders than nonresponders (p < 0.0001) and at a cutoff value ≥8.04 ng/mL it can predict treatment response by 77.8% sensitivity and 92.9% specificity, while both AFP and viremia were significantly lower in responders than nonresponders, p < 0.0001 and p = 0.0003, respectively, and at cutoff values ≤3.265 ng/mL and ≤235,384 IU/mL, respectively, they can predict treatment response with a sensitivity of 83.3% for both and specificity of 85.7% and 78.6%, respectively. In multivariate analysis, adiponectin was found to be the only independent predictor of treatment response (p = 0.044). Conclusions. The pretreatment serum level of adiponectin can predict the likelihood of treatment response, thus avoiding toxicities for those unlikely to respond to therapy.

Safety and efficacy outcome of mentor alpha-1 inflatable penile prosthesis implantation for impotence treatment.

Science.gov (United States)

Goldstein, I; Newman, L; Baum, N; Brooks, M; Chaikin, L; Goldberg, K; McBride, A; Krane, R J

1997-03-01

We investigated safety and efficacy outcome pertaining to the Mentor Alpha-1, 3-piece inflatable penile prosthesis for impotence treatment. A 2-phase, multi-institutional, large scale retrospective study, with independently analyzed medical record (phase I) and questionnaire (phase II) data from consecutive eligible patients of 7 physician investigators was performed from March to October 1993. In phase I there were no morbidities of any type in 394 of the 434 patients (90.8%) (mean age 61 years, range 24 to 88) who underwent Alpha-1 implantation (mean followup 22.2 months, range 0.67 to 44.5). The risk of prosthesis malfunction (fluid leak and auto-inflation) was 2.5%. No cylinder aneurysms were reported. A total of 93.1% of Alpha-1 devices was free from explantation (4.4%) or revision surgery (2.5%) for approximately 2 years from the original implant date. Kaplan-Meier actuarial analyses revealed that cumulative survival of the Alpha-1 prostheses at 12, 24 and 36 months was 98 +/- 1%, 93 +/- 2% and 85 +/- 7% until device malfunction, and 91 +/- 2% 83 +/- 4% and 75 +/- 7% until surgical intervention (revision or explantation). In phase II 89% of the men claimed fulfilled expectations with the Alpha-1 prosthesis as impotence treatment. Satisfaction responses 80% or greater were noted with regard to intercourse ability and confidence, and device rigidity and function. Implantation did not result in greater than 80% satisfaction in partner relationships or feelings (as judged by the patient), social or work confidence, or intercourse frequency. Factors adversely affecting satisfaction included partner feelings of dissatisfaction (as judged by the patient), specific physician investigators and need for explantation/revision surgery. In 1 of the largest multi-institutional implant outcome studies thus far performed, safety and efficacy data concerning the Alpha-1 contemporary inflatable device were found markedly improved over earlier inflatable prostheses and now

Plasma alpha-defensin is associated with cardiovascular morbidity and mortality in type 1 diabetic patients

DEFF Research Database (Denmark)

Joseph, G.; Tarnow, L.; Astrup, A.S.

2008-01-01

CONTEXT: alpha-Defensins are antimicrobial peptides of the innate immune system. In addition, experimental evidence suggests that alpha-defensins are proatherogenic. OBJECTIVE: The objective of the study was to examine the predictive value of plasma alpha-defensin as a clinical marker of cardiova...... to the development of CVD or an innocent bystander Udgivelsesdato: 2008/4...

Alpha Resonant States in 13C

International Nuclear Information System (INIS)

Rodrigues, M. R. D.; Borello-Lewin, T.; Horodynski-Matsushigue, L. B.; Duarte, J. L. M.; Rodrigues, C. L.; Souza, M. A.; Miyake, H.; Cunsolo, A.; Cappuzzello, F.; Ukita, G. M.

2011-01-01

The 9 Be( 6 Li,d) 13 C reaction was used to investigate alpha resonant states in 13 C up to 15 MeV of excitation. The reaction was measured at a bombarding energy of 25.5 MeV employing the Sao Paulo Pelletron-Enge-Spectrograph facility and the nuclear emulsion detection technique. An energy resolution of 50 keV was obtained. Several narrow alpha resonant states not previously measured were detected, in particular the one at the (3α+n) threshold populated by an L = 2 transfer, revealing a 9 Be+α component for the 1/2 - cluster state candidate at this threshold. Experimental angular distributions are presented in comparison with DWBA predictions.

alpha-Amanitin induced apoptosis in primary cultured dog hepatocytes.

Directory of Open Access Journals (Sweden)

Adam Szelag

2010-06-01

Full Text Available Amatoxin poisoning is caused by mushroom species belonging to the genera Amanita, Galerina and Lepiota with the majority of lethal mushroom exposures attributable to Amanita phalloides. High mortality rate in intoxications with these mushrooms is principally a result of the acute liver failure following significant hepatocyte damage due to hepatocellular uptake of amatoxins. A wide variety of amatoxins have been isolated; however, alpha-amanitin (alpha-AMA appears to be the primary toxin. Studies in vitro and in vivo suggest that alpha-AMA does not only cause hepatocyte necrosis, but also may lead to apoptotic cell death. The objective of this study was to evaluate the complex hepatocyte apoptosis in alpha-AMA cytotoxicity. All experiments were performed on primary cultured canine hepatocytes. The cells were incubated for 12 h with alpha-AMA at a final concentration of 1, 5, 10 and 20 microM. Viability test (MTT assay, apoptosis evaluation (TUNEL reaction, detection of DNA laddering and electron microscopy were performed at 6 and 12 h of exposure to alpha-AMA. There was a clear correlation between hepatocyte viability, concentration of alpha-AMA and time of exposure to this toxin. The decline in cultured dog hepatocyte viability during the exposure to alpha-AMA is most likely preceded by enhanced cellular apoptosis. Our results demonstrate that apoptosis might contribute to pathogenesis of the severe liver injury in the course of amanitin intoxication, particularly during the early phase of poisoning.

Implementation of a complex multi-phase equation of state for cerium and its correlation with experiment

Energy Technology Data Exchange (ETDEWEB)

Cherne, Frank J [Los Alamos National Laboratory; Jensen, Brian J [Los Alamos National Laboratory; Elkin, Vyacheslav M [VNIITF

2009-01-01

The complexity of cerium combined with its interesting material properties makes it a desirable material to examine dynamically. Characteristics such as the softening of the material before the phase change, low pressure solid-solid phase change, predicted low pressure melt boundary, and the solid-solid critical point add complexity to the construction of its equation of state. Currently, we are incorporating a feedback loop between a theoretical understanding of the material and an experimental understanding. Using a model equation of state for cerium we compare calculated wave profiles with experimental wave profiles for a number of front surface impact (cerium impacting a plated window) experiments. Using the calculated release isentrope we predict the temperature of the observed rarefaction shock. These experiments showed that the release state occurs at different magnitudes, thus allowing us to infer where dynamic {gamma} - {alpha} phase boundary is.

High-alpha band synchronization across frontal, parietal and visual cortex mediates behavioral and neuronal effects of visuospatial attention.

Science.gov (United States)

Lobier, Muriel; Palva, J Matias; Palva, Satu

2018-01-15

Visuospatial attention prioritizes processing of attended visual stimuli. It is characterized by lateralized alpha-band (8-14 Hz) amplitude suppression in visual cortex and increased neuronal activity in a network of frontal and parietal areas. It has remained unknown what mechanisms coordinate neuronal processing among frontoparietal network and visual cortices and implement the attention-related modulations of alpha-band amplitudes and behavior. We investigated whether large-scale network synchronization could be such a mechanism. We recorded human cortical activity with magnetoencephalography (MEG) during a visuospatial attention task. We then identified the frequencies and anatomical networks of inter-areal phase synchronization from source localized MEG data. We found that visuospatial attention is associated with robust and sustained long-range synchronization of cortical oscillations exclusively in the high-alpha (10-14 Hz) frequency band. This synchronization connected frontal, parietal and visual regions and was observed concurrently with amplitude suppression of low-alpha (6-9 Hz) band oscillations in visual cortex. Furthermore, stronger high-alpha phase synchronization was associated with decreased reaction times to attended stimuli and larger suppression of alpha-band amplitudes. These results thus show that high-alpha band phase synchronization is functionally significant and could coordinate the neuronal communication underlying the implementation of visuospatial attention. Copyright © 2017 Elsevier Inc. All rights reserved.

Stabilization of {alpha}-amylase by using anionic surfactant during the immobilization process

Energy Technology Data Exchange (ETDEWEB)

El-Batal, A.I. [National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt); Atia, K.S. [Nuclear Research Center, Radioisotopes Applications Division, Abo-Zable, P.O. Box 13759, Cairo (Egypt)]. E-mail: ks_atia@yahoo.com; Eid, M. [National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt)

2005-10-01

This work describes the entrapment of {alpha}-amylase into butylacrylate-acrylic acid copolymer (BuA/AAc) using {gamma} irradiation. The effect of an anionic surfactant (AOT), the reuse efficiency, and kinetic behavior of immobilized {alpha}-amylase were studied. Covering of {alpha}-amylase with bis-(2-ethylhexyl)sulfosuccinate sodium salt (AOT) made the enzyme more stable than the uncovered form. The hydrolytic activity of the pre-coated immobilized {alpha}-amylase was increased below the critical micelle concentration (cmc) (10mmol/L). The results showed an increase in the relative activity with increase in the degree of hydration. The pre-coated immobilized {alpha}-amylase showed a higher k{sub cat}/K{sub m} and lower activation energy compared to the free and uncoated-immobilized preparation, respectively. The results suggest that the immobilization of {alpha}-amylase is a potentially useful approach for commercial starch hydrolysis in two-phase systems.

Predictive Duty Cycle Control of Three-Phase Active-Front-End Rectifiers

DEFF Research Database (Denmark)

Song, Zhanfeng; Tian, Yanjun; Chen, Wei

2016-01-01

This paper proposed an on-line optimizing duty cycle control approach for three-phase active-front-end rectifiers, aiming to obtain the optimal control actions under different operating conditions. Similar to finite control set model predictive control strategy, a cost function previously...

Dosimetry of natural and man-made alpha emitters in plankton

International Nuclear Information System (INIS)

Paschoa, A.S.; Baptista, G.B.; Wrenn, M.E.; Eisenbrid, M.

1980-11-01

Comparison between the natural and man-made alpha radiation dose rates to plankton can be important for predicting the potential long-term effects on aquatic biota resulting from the routine or accidental radioactive releases from the nuclear fuel cycle. A contribution is made here towards the goal of comparing natural with man-made alpha radiation dose rates to plankton using the same method of calculation in both cases. (Author) [pt

Alpha Anisotropy Studies of Near-Spherical and Deformed Nuclei

CERN Multimedia

Van Duppen, P

2002-01-01

% IS329 \\\\ \\\\ Although it was the first decay mode to be discovered, the process of $\\alpha$-particle emission is still poorly understood. A few years ago the first systematic study of anisotropic $\\alpha$-decay triggered renewed theoretical interest. Nevertheless, today the theories are still not adequate enough and more experimental data are urgently needed. We therefore measure the $\\alpha$-anisotropies of the favoured transitions of a number of near-spherical Rn and At isotopes, and of deformed nuclei near A=220. As the different models yield contradictory predictions for the transitions that are investigated, the measurements will allow to discern on their validity. They will at the same time provide the necessary basis for further theoretical developments.

Phase 2 Randomized Controlled Trial of Radiation Therapy Plus Concurrent Interferon-Alpha and Retinoic Acid Versus Cisplatin for Stage III Cervical Carcinoma

Energy Technology Data Exchange (ETDEWEB)

Basu, Partha, E-mail: BasuP@iarc.fr [Screening Group, Early Detection and Prevention Section, International Agency for Research on Cancer, Lyon (France); Jenson, Alfred Bennett [James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky (United States); Majhi, Tapas; Choudhury, Prabir [Department of Radiation Oncology, Chittaranjan National Cancer Institute, Kolkata (India); Mandal, Ranajit; Banerjee, Dipanwita [Department of Gynecological Oncology, Chittaranjan National Cancer Institute, Kolkata (India); Biswas, Jaydip [Department of Surgical Oncology, Chittaranjan National Cancer Institute, Kolkata (India); Pan, Jianmin; Rai, Shesh Nath; Ghim, Shin je; Miller, Donald [James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky (United States)

2016-01-01

Purpose: Because a combination of retinoic acid, interferon-alpha, and radiation therapy demonstrated synergistic action and effectiveness to treat advanced cervical cancers in earlier studies, we designed this randomized phase 2 open-label trial to assess efficacy and safety of interferon alpha-2b (IFN) and 13-cis-retinoic acid (RA) administered concomitantly with radiation therapy (IFN-RA-radiation) to treat stage III cervical cancer. Methods and Materials: Stage III cervical cancer patients were randomized to study and control groups in a 1:1 ratio. All patients were treated with radiation therapy; study arm patients received IFN (3 × 10{sup 6} IU subcutaneously) 3 times a week for 4 weeks and daily RA (40 mg orally) for 30 days starting on day 1 of radiation, whereas control arm patients received weekly cisplatinum (40 mg/m{sup 2}) for 5 weeks during radiation. Patients were followed for 3 years. The primary endpoint was overall survival at 3 years. Results: Patients in the study (n=104) and control (n=105) groups were comparable for clinicopathological characteristics, radiation therapy–related variables and treatment response. Proportions of disease-free patients in the study and control groups were 38.5% and 44.8%, respectively, after median follow-up of 29.2 months. Hazard ratios were 0.67 (95% confidence interval [CI]: 0.44-1.01) and 0.69 (95% CI: 0.44-1.06) for overall and disease-fee survival, respectively, comparing the study group to control, and demonstrated an inferior outcome with RA-IFN-radiation, although differences were statistically nonsignificant. Kaplan-Meier curves of disease-free and overall survival probabilities also showed inferior survival in the study group compared to those in the control. Acute toxicities of chemoradiation were significantly higher with 2 acute toxicity-related deaths. Conclusions: Treatment with RA-IFN-radiation did not demonstrate survival advantage over chemoradiation despite being less toxic. The

CFD prediction of flow and phase distribution in fuel assemblies with spacers

Energy Technology Data Exchange (ETDEWEB)

Anglart, H.; Nylund, O. [ABB Atom AB, Vasteras (Switzerland); Kurul, N. [Rensselaer Polytechnic Institute, Troy, NY (United States)] [and others

1995-09-01

This paper is concerned with the modeling and computation of multi-dimensional two-phase flows in BWR fuel assemblies. The modeling principles are presented based on using a two-fluid model in which lateral interfacial effects are accounted for. This model has been used to evaluate the velocity fields of both vapor and liquid phases, as well as phase distribution, between fuel elements in geometries similar to BWR fuel bundles. Furthermore, this model has been used to predict, in a detailed mechanistic manner, the effects of spacers on flow and phase distribution between, and pressure drop along, fuel elements. The related numerical simulations have been performed using a CFD computer code, CFDS-FLOW3D.

Statistical process control for alpha spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Richardson, W; Majoras, R E [Oxford Instruments, Inc. P.O. Box 2560, Oak Ridge TN 37830 (United States); Joo, I O; Seymour, R S [Accu-Labs Research, Inc. 4663 Table Mountain Drive, Golden CO 80403 (United States)

1995-10-01

Statistical process control(SPC) allows for the identification of problems in alpha spectroscopy processes before they occur, unlike standard laboratory Q C which only identifies problems after a process fails. SPC tools that are directly applicable to alpha spectroscopy include individual X-charts and X-bar charts, process capability plots, and scatter plots. Most scientists are familiar with the concepts the and methods employed by SPC. These tools allow analysis of process bias, precision, accuracy and reproducibility as well as process capability. Parameters affecting instrument performance are monitored and analyzed using SPC methods. These instrument parameters can also be compared to sampling, preparation, measurement, and analysis Q C parameters permitting the evaluation of cause effect relationships. Three examples of SPC, as applied to alpha spectroscopy , are presented. The first example investigates background contamination using averaging to show trends quickly. A second example demonstrates how SPC can identify sample processing problems, analyzing both how and why this problem occurred. A third example illustrates how SPC can predict when an alpha spectroscopy process is going to fail. This allows for an orderly and timely shutdown of the process to perform preventative maintenance, avoiding the need to repeat costly sample analyses. 7 figs., 2 tabs.

Statistical process control for alpha spectroscopy

International Nuclear Information System (INIS)

Richardson, W.; Majoras, R.E.; Joo, I.O.; Seymour, R.S.

1995-01-01

Statistical process control(SPC) allows for the identification of problems in alpha spectroscopy processes before they occur, unlike standard laboratory Q C which only identifies problems after a process fails. SPC tools that are directly applicable to alpha spectroscopy include individual X-charts and X-bar charts, process capability plots, and scatter plots. Most scientists are familiar with the concepts the and methods employed by SPC. These tools allow analysis of process bias, precision, accuracy and reproducibility as well as process capability. Parameters affecting instrument performance are monitored and analyzed using SPC methods. These instrument parameters can also be compared to sampling, preparation, measurement, and analysis Q C parameters permitting the evaluation of cause effect relationships. Three examples of SPC, as applied to alpha spectroscopy , are presented. The first example investigates background contamination using averaging to show trends quickly. A second example demonstrates how SPC can identify sample processing problems, analyzing both how and why this problem occurred. A third example illustrates how SPC can predict when an alpha spectroscopy process is going to fail. This allows for an orderly and timely shutdown of the process to perform preventative maintenance, avoiding the need to repeat costly sample analyses. 7 figs., 2 tabs

Differentiation of the mRNA transcripts originating from the alpha 1- and alpha 2-globin loci in normals and alpha-thalassemics.

OpenAIRE

Liebhaber, S A; Kan, Y W

1981-01-01

The alpha-globin polypeptide is encoded by two adjacent genes, alpha 1 and alpha 2. In the normal diploid state (alpha alpha/alpha alpha) all four alpha-globin genes are expressed. Loss or dysfunction of one or more of these genes leads to deficient alpha-globin production and results in alpha-thalassemia. We present a technique to differentially assess the steady-state levels of the alpha 1- and alpha-2-globin messenger RNA (mRNA) transcripts and thus delineate the relative level of expressi...

Prediction of therapy response to interferon-alpha in chronic viral hepatitis-B by liver and hepatobiliary scintigraphy

International Nuclear Information System (INIS)

Caglar, M.; Sari, O.; Akcan, Y.

2002-01-01

Interferon (IFN) provides effective treatment in some patients with chronic hepatitis. The clarification of factors predictive of therapy response would be helpful in identifying patients who would benefit from treatment. In this study, we evaluated the potential utility of Tc-99m sulfur colloid liver/spleen and Tc-99m-disofenin hepatobiliary scintigraphy to predict therapy response to IFN in patients with chronic active hepatitis. The study group consisted of ten patients with chronic viral hepatitis B who were treated with 4.5 units of interferon alpha for 12 months. Prior to the start of the therapy, sulfur colloid scintigraphy was obtained by which the liver/spleen ratios were derived. Hepatobiliary scintigraphy was performed on a separate day and time-activity curves were generated from regions of interest drawn over the liver, heart and gall-bladder. The index of blood and liver clearance time was calculated. Histological grading and laboratory values were obtained for clinical correlation. Responders (n=6) to IFN were defined as those who improved clinically with normalized transaminase levels and had hepatitis B envelope antigen (HBeAg) seroconversion. On sulfur colloid (SC) scintigraphy, the liver/spleen ratio of non-responders was significantly lower than responders (median values: 0.69 vs. 1.16, p=0.01) but on hepatobiliary scintigraphy no statistically significant parameters were found to predict response to interferon therapy. (author)

Experimental determination and thermodynamic modeling of phase equilibrium and protein partitioning in aqueous two-phase systems containing biodegradable salts

International Nuclear Information System (INIS)

Perez, Brenda; Malpiedi, Luciana Pellegrini; Tubío, Gisela; Nerli, Bibiana; Alcântara Pessôa Filho, Pedro de

2013-01-01

Highlights: ► Binodal data of systems (water + polyethyleneglycol + sodium) succinate are reported. ► Pitzer model describes the phase equilibrium of systems formed by polyethyleneglycol and biodegradable salts satisfactorily. ► This simple thermodynamic framework was able to predict the partitioning behaviour of model proteins acceptably well. - Abstract: Phase diagrams of sustainable aqueous two-phase systems (ATPSs) formed by polyethyleneglycols (PEGs) of different average molar masses (4000, 6000, and 8000) and sodium succinate are reported in this work. Partition coefficients (Kps) of seven model proteins: bovine serum albumin, catalase, beta-lactoglobulin, alpha-amylase, lysozyme, pepsin, urease and trypsin were experimentally determined in these systems and in ATPSs formed by the former PEGs and other biodegradable sodium salts: citrate and tartrate. An extension of Pitzer model comprising long and short-range term contributions to the excess Gibbs free energy was used to describe the (liquid + liquid) equilibrium. Comparison between experimental and calculated tie line data showed mean deviations always lower than 3%, thus indicating a good correlation. The partition coefficients were modeled by using the same thermodynamic approach. Predicted and experimental partition coefficients correlated quite successfully. Mean deviations were found to be lower than the experimental uncertainty for most of the assayed proteins.

P stabilizes dark matter and with CP can predict leptonic phases

Energy Technology Data Exchange (ETDEWEB)

Kuchimanchi, Ravi

2014-02-15

We find that spontaneously broken parity (P) or left-right symmetry stabilizes darkmatter in a beautiful way. If dark matter has a non-real intrinsic parity ±i (e.g. if it entails Majorana fermions), parity can ensure that it cannot decay to all normal particles with real intrinsic parities. However, if Majorana couplings are absent either in the lepton or the dark sector, P symmetry can be redefined to remove relative non-real intrinsic phases. It is therefore predicted that neutrinos and dark matter fermions must have Majorana masses if dark matter is stable due to parity. The strong CP problem is solved by additionally imposing CP and including vectorlike fermions that help generate CP violation. If leptonlike heavy fermions are provided purely imaginary intrinsic parity phase, they do not couple to the usual leptons, and leptonic CP phases are not generated, which is a testable prediction. Experimentally if leptonic CP phases are not found (if they are consistent with 0 or π) it can be evidence for the type of models in this work where CP is spontaneously or softly broken and there is also a second hidden or softly broken symmetry such as P, Z{sub 2} or Z{sub 4}. However, leptonic CP violation can be present in closely related or some nonminimal versions of these models, such as by also including vectorlike leptons with real intrinsic parities. (orig.)

Structural Phase Transition Nomenclature, Report of an IUCr Working Group on Phase Transition Nomenclature

NARCIS (Netherlands)

Toleddano, J.C.; Glazer, A.M.; Hahn, Th.; Parthe, E.; Roth, R.S.; Berry, R.S.; Metselaar, R.; Abrahams, S.C.

1998-01-01

A compact and intuitive nomenclature is recommended for naming each phase formed by a given material in a sequence of phase transitions as a function of temperature and/or pressure. The most commonly used label for each phase in a sequence, such as [alpha], [beta], ..., I, II, ... etc., is included

Formation of alpha-dicarbonyl compounds in beer during storage of Pilsner.

Science.gov (United States)

Bravo, Adriana; Herrera, Julio C; Scherer, Erika; Ju-Nam, Yon; Rübsam, Heinrich; Madrid, Jorge; Zufall, Carsten; Rangel-Aldao, Rafael

2008-06-11

With the aim of determining the formation of alpha-dicarbonyl intermediates during beer aging on the shelf, alpha-dicarbonyls were identified and quantified after derivatization with 1,2-diaminobenze to generate quinoxalines. The sensory effects of alpha-dicarbonyls were evaluated by the quantification of key Strecker aldehydes and by GC-olfactometry (GCO)analysis of beer headspace using solid phase microextraction. Four alpha-dicarbonyls, reported here for the first time, were detected in fresh and aged beers, three were derived from the 2,3-enolization pathway of mono- and disaccharides, and the fourth was derived from the epimerization of 3-deoxy-2-hexosulose. Ten alpha-dicarbonyls were quantified during beer processing and during different periods of beer aging at 28 degrees C. The aging periods were from 15 to 105 days. During beer aging, 1-deoxydiuloses were produced and degraded, while 1,4-dideoxydiuloses were produced at the highest rates. The GCO analysis indicated that forced beer aging increased the amounts of furaneol, trans-2-nonenal, and phenylacetaldehyde. The blockage of alpha-dicarbonyls inhibited the accumulation of sensory-active aldehydes in the beer headspace.

Alternative splicing of T cell receptor (TCR) alpha chain transcripts containing V alpha 1 or V alpha 14 elements.

Science.gov (United States)

Mahotka, C; Hansen-Hagge, T E; Bartram, C R

1995-10-01

Human acute lymphoblastic leukemia cell lines represent valuable tools to investigate distinct steps of the complex regulatory pathways underlying T cell receptor recombination and expression. A case in point are V delta 2D delta 3 and subsequent V delta 2D delta 3J alpha rearrangements observed in human leukemic pre-B cells as well as in normal lymphopoiesis. The functional expression of these unusual (VD) delta (JC) alpha hybrids is almost exclusively prevented by alternative splicing events. In this report we show that alternative splicing at cryptic splice donor sites within V elements is not a unique feature of hybrid TCR delta/alpha transcripts. Among seven V alpha families analyzed by RT-PCR, alternatively spliced products were observed in TCR alpha recombinations containing V alpha 1 or V alpha 14 elements. In contrast to normal peripheral blood cells and thymocytes, the leukemia cell line JM expressing functional V alpha 1J alpha 3C alpha transcripts lacked evidence of aberrant TCR alpha RNA species.

Impact of gender and menstrual cycle phase on plasma cytokine concentrations.

LENUS (Irish Health Repository)

O'Brien, Sinead M

2012-02-03

OBJECTIVE: The lifetime prevalence of major depression is twice as high in females as in males. Depression is known to increase at periods where there are changes in gonadal hormones. We examined pro- and anti-inflammatory cytokine levels during the normal menstrual cycle of healthy females compared to similar time points in healthy males. METHODS: Plasma concentrations of interleukin (IL)-4, IL-6, IL-8, IL-10, tumour necrosis factor-alpha (TNF-alpha) and soluble IL-6 receptor (sIL-6R) were measured with enzyme-linked immunosorbent assays in healthy females during the normal ovulatory menstrual cycle and also in males at similar time points. RESULTS: The luteal phase of the menstrual cycle is associated with increased production of sIL-6R, IL-4 and TNF-alpha compared to the early follicular phase. No change was observed in IL-6, IL-8 and IL-10 concentration throughout the menstrual cycle. We found IL-4 positively correlated with oestrogen while TNF-alpha positively correlated with progesterone. Females were found to have significantly higher concentrations of TNF-alpha and sIL-6R across all phases of the menstrual cycle, compared to males across similar time points. CONCLUSION: The normal menstrual cycle is associated with increased production of sIL-6R, IL-4 and TNF-alpha in the luteal phase compared to the early follicular phase. Females have significantly higher concentrations of sIL-6R and TNF-alpha at all time points across the menstrual cycle than males.

The effect of peptides and ions interacting with an electrically neutral membrane interface on the structure and stability of lipid membranes in the liquid-crystalline phase and in the liquid-ordered phase

Energy Technology Data Exchange (ETDEWEB)

Sano, Ryoko [Department of Physics, Faculty of Science, Shizuoka University, Shizuoka, 422-8529 (Japan); Masum, Shah Md [Material Science, Graduate School of Science and Engineering, Shizuoka University, 422-8529 (Japan); Tanaka, Tomoki [Material Science, Graduate School of Science and Engineering, Shizuoka University, 422-8529 (Japan); Yamashita, Yuko [Department of Physics, Faculty of Science, Shizuoka University, Shizuoka, 422-8529 (Japan); Levadny, Victor [Department of Physics, Faculty of Science, Shizuoka University, Shizuoka, 422-8529 (Japan); Scientific Council for Cybernetics, Russian Academy of Sciences, Vavilov street 34, 333117, Moscow (Russian Federation); Yamazaki, Masahito [Department of Physics, Faculty of Science, Shizuoka University, Shizuoka, 422-8529 (Japan); Material Science, Graduate School of Science and Engineering, Shizuoka University, 422-8529 (Japan)

2005-08-10

We investigated the effects of a de novo designed peptide, WLFLLKKK (peptide-1) and La{sup 3+}, which can bind with the electrically neutral lipid membrane interface, on the stability of the phosphatidylcholine (PC) membrane in the L{sub {alpha}} phase and that of the liquid-ordered (lo) phase membranes. The results of spacing of the multilamellar vesicle and shape changes of the giant unilamellar vesicle (GUV) indicate that the peptide-1 can be partitioned into the membrane interface in the L{sub {alpha}} phase but not into that in the lo phase. La{sup 3+} induced shape changes of GUVs of the lo phase membrane, which are the same as those of GUVs in the L{sub {alpha}} phase. This indicates that the binding of La{sup 3+} induced an increase in the lateral compression pressure of the membrane, which decreased the surface area of the membrane in the lo phase. The difference of the membrane interface between the L{sub {alpha}} phase and the lo phase is discussed.

Thermal Phase Variations of WASP-12b: Defying Predictions

Science.gov (United States)

Cowan, Nicolas B.; Machalek, Pavel; Croll, Bryce; Shekhtman, Louis M.; Burrows, Adam; Deming, Drake; Greene, Tom; Hora, Joseph L.

2012-01-01

We report Warm Spitzer full-orbit phase observations of WASP-12b at 3.6 and 4.5 micrometers. This extremely inflated hot Jupiter is thought to be overflowing its Roche lobe, undergoing mass loss and accretion onto its host star, and has been claimed to have a C/O ratio in excess of unity. We are able to measure the transit depths, eclipse depths, thermal and ellipsoidal phase variations at both wavelengths. The large-amplitude phase variations, combined with the planet's previously measured dayside spectral energy distribution, are indicative of non-zero Bond albedo and very poor day-night heat redistribution. The transit depths in the mid-infrared-(R(sub p)/R(sub *))(sup 2) = 0.0123(3) and 0.0111(3) at 3.6 and 4.5 micrometers, respectively-indicate that the atmospheric opacity is greater at 3.6 than at 4.5 micrometers, in disagreement with model predictions, irrespective of C/O ratio. The secondary eclipse depths are consistent with previous studies: F(sub day)/F(sub *) = 0.0038(4) and 0.0039(3) at 3.6 and 4.5 micrometers, respectively. We do not detect ellipsoidal variations at 3.6 micrometers, but our parameter uncertainties-estimated via prayer-bead Monte Carlo-keep this non-detection consistent with model predictions. At 4.5 micrometers, on the other hand, we detect ellipsoidal variations that are much stronger than predicted. If interpreted as a geometric effect due to the planet's elongated shape, these variations imply a 3:2 ratio for the planet's longest:shortest axes and a relatively bright day-night terminator. If we instead presume that the 4.5 micrometer ellipsoidal variations are due to uncorrected systematic noise and we fix the amplitude of the variations to zero, the best-fit 4.5 micrometer transit depth becomes commensurate with the 3.6 micrometer depth, within the uncertainties. The relative transit depths are then consistent with a solar composition and short scale height at the terminator. Assuming zero ellipsoidal variations also yields a much

THERMAL PHASE VARIATIONS OF WASP-12b: DEFYING PREDICTIONS

International Nuclear Information System (INIS)

Cowan, Nicolas B.; Shekhtman, Louis M.; Machalek, Pavel; Croll, Bryce; Burrows, Adam; Deming, Drake; Greene, Tom; Hora, Joseph L.

2012-01-01

We report Warm Spitzer full-orbit phase observations of WASP-12b at 3.6 and 4.5 μm. This extremely inflated hot Jupiter is thought to be overflowing its Roche lobe, undergoing mass loss and accretion onto its host star, and has been claimed to have a C/O ratio in excess of unity. We are able to measure the transit depths, eclipse depths, thermal and ellipsoidal phase variations at both wavelengths. The large-amplitude phase variations, combined with the planet's previously measured dayside spectral energy distribution, are indicative of non-zero Bond albedo and very poor day-night heat redistribution. The transit depths in the mid-infrared—(R p /R * ) 2 = 0.0123(3) and 0.0111(3) at 3.6 and 4.5 μm, respectively—indicate that the atmospheric opacity is greater at 3.6 than at 4.5 μm, in disagreement with model predictions, irrespective of C/O ratio. The secondary eclipse depths are consistent with previous studies: F day /F * = 0.0038(4) and 0.0039(3) at 3.6 and 4.5 μm, respectively. We do not detect ellipsoidal variations at 3.6 μm, but our parameter uncertainties—estimated via prayer-bead Monte Carlo—keep this non-detection consistent with model predictions. At 4.5 μm, on the other hand, we detect ellipsoidal variations that are much stronger than predicted. If interpreted as a geometric effect due to the planet's elongated shape, these variations imply a 3:2 ratio for the planet's longest:shortest axes and a relatively bright day-night terminator. If we instead presume that the 4.5 μm ellipsoidal variations are due to uncorrected systematic noise and we fix the amplitude of the variations to zero, the best-fit 4.5 μm transit depth becomes commensurate with the 3.6 μm depth, within the uncertainties. The relative transit depths are then consistent with a solar composition and short scale height at the terminator. Assuming zero ellipsoidal variations also yields a much deeper 4.5 μm eclipse depth, consistent with a solar composition and modest

Importance of the gas phase role to the prediction of energetic material behavior: An experimental study

International Nuclear Information System (INIS)

Ali, A.N.; Son, S.F.; Asay, B.W.; Sander, R.K.

2005-01-01

Various thermal (radiative, conductive, and convective) initiation experiments are performed to demonstrate the importance of the gas phase role in combustion modeling of energetic materials (EM). A previously published condensed phase model that includes a predicted critical irradiance above which ignition is not possible is compared to experimental laser ignition results for octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and 2,4,6-trinitrotoluene (TNT). Experimental results conflict with the predicted critical irradiance concept. The failure of the model is believed to result from a misconception about the role of the gas phase in the ignition process of energetic materials. The model assumes that ignition occurs at the surface and that evolution of gases inhibits ignition. High speed video of laser ignition, oven cook-off and hot wire ignition experiments captures the ignition of HMX and TNT in the gas phase. A laser ignition gap test is performed to further evaluate the effect of gas phase laser absorption and gas phase disruption on the ignition process. Results indicate that gas phase absorption of the laser energy is probably not the primary factor governing the gas phase ignition observations. It is discovered that a critical gap between an HMX pellet and a salt window of 6 mm±0.4 mm exists below which ignition by CO 2 laser is not possible at the tested irradiances of 29 W/cm 2 and 38 W/cm 2 for HMX ignition. These observations demonstrate that a significant disruption of the gas phase, in certain scenarios, will inhibit ignition, independent of any condensed phase processes. These results underscore the importance of gas phase processes and illustrate that conditions can exist where simple condensed phase models are inadequate to accurately predict the behavior of energetic materials

Importance of the gas phase role to the prediction of energetic material behavior: An experimental study

Science.gov (United States)

Ali, A. N.; Son, S. F.; Asay, B. W.; Sander, R. K.

2005-03-01

Various thermal (radiative, conductive, and convective) initiation experiments are performed to demonstrate the importance of the gas phase role in combustion modeling of energetic materials (EM). A previously published condensed phase model that includes a predicted critical irradiance above which ignition is not possible is compared to experimental laser ignition results for octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and 2,4,6-trinitrotoluene (TNT). Experimental results conflict with the predicted critical irradiance concept. The failure of the model is believed to result from a misconception about the role of the gas phase in the ignition process of energetic materials. The model assumes that ignition occurs at the surface and that evolution of gases inhibits ignition. High speed video of laser ignition, oven cook-off and hot wire ignition experiments captures the ignition of HMX and TNT in the gas phase. A laser ignition gap test is performed to further evaluate the effect of gas phase laser absorption and gas phase disruption on the ignition process. Results indicate that gas phase absorption of the laser energy is probably not the primary factor governing the gas phase ignition observations. It is discovered that a critical gap between an HMX pellet and a salt window of 6mm±0.4mm exists below which ignition by CO2 laser is not possible at the tested irradiances of 29W /cm2 and 38W/cm2 for HMX ignition. These observations demonstrate that a significant disruption of the gas phase, in certain scenarios, will inhibit ignition, independent of any condensed phase processes. These results underscore the importance of gas phase processes and illustrate that conditions can exist where simple condensed phase models are inadequate to accurately predict the behavior of energetic materials.

ALPHA/AMPU, Radionuclide Radioactivity from Alpha Spectrometer Measurements

International Nuclear Information System (INIS)

Sill, D.S.

1990-01-01

1 - Description of program or function: The two computer programs, ALPHA and AMPU, take raw data obtained from alpha spectrometry and from these calculate activities and uncertainties of the radionuclides present in the sample. ALPHA determines activities of any alpha emitter in a sample that has been directly precipitated with NdF 3 . AMPU determines the Pu-239, Pu-238,and Am-241 activities using Pu-236 and Am-243 tracers. 2 - Method of solution: These programs propagate all random and systematic uncertainties, found anywhere in the experimental process, to the final result. The result is rounded and is in decimal agreement with the uncertainty. 3 - Restrictions on the complexity of the problem: In ALPHA, a chemical yield of 98% is assumed

Prediction of lung cells oncogenic transformation for induced radon progeny alpha particles using sugarscape cellular automata.

Science.gov (United States)

Baradaran, Samaneh; Maleknasr, Niaz; Setayeshi, Saeed; Akbari, Mohammad Esmaeil

2014-01-01

Alpha particle irradiation from radon progeny is one of the major natural sources of effective dose in the public population. Oncogenic transformation is a biological effectiveness of radon progeny alpha particle hits. The biological effects which has caused by exposure to radon, were the main result of a complex series of physical, chemical, biological and physiological interactions. The cellular and molecular mechanisms for radon-induced carcinogenesis have not been clear yet. Various biological models, including cultured cells and animals, have been found useful for studying the carcinogenesis effects of radon progeny alpha particles. In this paper, sugars cape cellular automata have been presented for computational study of complex biological effect of radon progeny alpha particles in lung bronchial airways. The model has included mechanism of DNA damage, which has been induced alpha particles hits, and then formation of transformation in the lung cells. Biomarkers were an objective measure or evaluation of normal or abnormal biological processes. In the model, the metabolism rate of infected cell has been induced alpha particles traversals, as a biomarker, has been followed to reach oncogenic transformation. The model results have successfully validated in comparison with "in vitro oncogenic transformation data" for C3H 10T1/2 cells. This model has provided an opportunity to study the cellular and molecular changes, at the various stages in radiation carcinogenesis, involving human cells. It has become well known that simulation could be used to investigate complex biomedical systems, in situations where traditional methodologies were difficult or too costly to employ.

Serum Adiponectin, Vitamin D, and Alpha-Fetoprotein in Children with Chronic Hepatitis C: Can They Predict Treatment Response?

Directory of Open Access Journals (Sweden)

Mohamed Ahmed Khedr

2015-01-01

Full Text Available Background & Aims. The currently available treatment for chronic hepatitis C (CHC in children is costly and with much toxicity. So, predicting the likelihood of response before starting therapy is important. Methods. Serum adiponectin, vitamin D, and alpha-fetoprotein (AFP were measured before starting pegylated-interferon/ribavirin therapy for 50 children with CHC. Another 21 healthy children were recruited as controls. Results. Serum adiponectin, vitamin D, and AFP were higher in the CHC group than healthy controls (p<0.0001, p=0.071, and p=0.87, resp.. In univariate analysis, serum adiponectin was significantly higher in responders than nonresponders (p<0.0001 and at a cutoff value ≥8.04 ng/mL it can predict treatment response by 77.8% sensitivity and 92.9% specificity, while both AFP and viremia were significantly lower in responders than nonresponders, p<0.0001 and p=0.0003, respectively, and at cutoff values ≤3.265 ng/mL and ≤235,384 IU/mL, respectively, they can predict treatment response with a sensitivity of 83.3% for both and specificity of 85.7% and 78.6%, respectively. In multivariate analysis, adiponectin was found to be the only independent predictor of treatment response (p=0.044. Conclusions. The pretreatment serum level of adiponectin can predict the likelihood of treatment response, thus avoiding toxicities for those unlikely to respond to therapy.

Simulations of alpha parameters in a TFTR DT supershot with high fusion power

International Nuclear Information System (INIS)

Budny, R.V.; Bell, M.G.; Janos, A.C.

1995-07-01

A TFTR supershot with a plasma current of 2.5 MA, neutral beam heating power of 33.7 MW, and a peak DT fusion power of 7.5 MW is studied using the TRANSP plasma analysis code. Simulations of alpha parameters such as the alpha heating, pressure, and distributions in energy and v parallel /v are given. The effects of toroidal ripple and mixing of the fast alpha particles during the sawteeth observed after the neutral beam injection phase are modeled. The distributions of alpha particles on the outer midplane are peaked near forward and backward v parallel /v. Ripple losses deplete the distributions in the vicinity of v parallel /v ∼-0.4. Sawtooth mixing of fast alpha particles is computed to reduce their central density and broaden their width in energy

The Sleep–Wake Cycle in the Nicotinic Alpha-9 Acetylcholine Receptor Subunit Knock-Out Mice

Directory of Open Access Journals (Sweden)

Natalia Madrid-López

2017-10-01

Full Text Available There is a neural matrix controlling the sleep–wake cycle (SWC embedded within high ranking integrative mechanisms in the central nervous system. Nicotinic alpha-9 acetylcholine receptor subunit (alpha-9 nAChR participate in physiological processes occurring in sensory, endocrine and immune systems. There is a relationship between the SWC architecture, body homeostasis and sensory afferents so that disruption of afferent signaling is expected to affect the temporal organization of sleep and wake states. The analysis of the SWC of 9 nAChR knock-out animals may help to reveal the contribution of alpha-9 nAChR to sleep chronobiological determinants. Here we explore the polysomnogram in chronically implanted alpha-9 nAChR knock-out (KO and wild-type (WT individuals of the hybrid CBA/Sv129 mouse strain. Records were obtained in isolation chambers under a stable 12:12 light:dark cycle (LD. To unmask the 24-h modulation of the SWC a skeleton photoperiod (SP protocol was performed. Under LD the daily quota (in % of wakefulness (W, NREM sleep and REM sleep obtained in KO and WT animals were 45, 48 and 7, and 46, 46 and 8 respectively. Both groups exhibit nocturnal phase preference of W as well as diurnal and unimodal phase preference of NREM and REM sleep. The acrophase mean angles of KO vs. WT genotypes were not different (Zeitgeber Time: 6.5 vs. 14.9 for W, 4.3 vs. 2.8 for NREM sleep and 5.3 vs. 3.4 for REM sleep, respectively. Transference to SP do not affect daily state quotas, phase preferences and acrophases among genotypes. Unmasking phenomena of the SWC such as wake increment during the rest phase under SP was evident only among WT mice suggesting the involvement of retinal structures containing alpha-9 nAChR in masking processes. Furthermore, KO animals exhibit longer NREM and REM sleep episodes that is independent of illumination conditions. Consolidated diurnal NREM sleep contributed to obtain higher values of NREM sleep delta-EEG activity

Effect of microstructure evolution of the lamellar alpha on impact toughness in a two-phase titanium alloy

International Nuclear Information System (INIS)

Xu, Jianwei; Zeng, Weidong; Zhao, Yawei; Jia, Zhiqiang

2016-01-01

The effects of the evolution of the lamellar alpha microstructure on the impact toughness of Ti-17 alloy are investigated. For this purpose, the beta-processed material is isothermally forged at 820 °C and subsequently heat treated using the combination of solid solution and aging treatment. Then the impact tests are carried out at room temperature. The corresponding microstructure and fracture surface are examined by scanning electron microscope (SEM). Microstructural observations reveal that globularization behavior is the main feature of microstructure evolution and the globularization fraction increases with the increasing of prestrain. However, globularization behavior has a negative influence on the impact toughness of Ti-17 alloy. In this work, the impact toughness have been obtained in the range of 29–55 J/cm 2 via varying globularization fraction of alpha phase. A linear relationship between the impact toughness and globularization fraction can be observed though the quantitative analysis. The linear equation is expressed as A=−0.3232f+59.885. The two major reasons can be used to explain the effect of globularization fraction on the impact property of Ti-17 alloy. One explanation is that the lamellar structure can provide excellent interfacial strengthening effect, which can improve the toughness of material, and makes it not easy to fracture. On the other hand, the fracture surface of specimen with the lamellar structure has larger amplitude of ups and downs. A long crack path length will be generated during fracture process. By contrast, the fracture of specimen with the equiaxed structure presents more flat surface and shorter crack path.

Four-Phase Dendritic Model for the Prediction of Macrosegregation, Shrinkage Cavity, and Porosity in a 55-Ton Ingot

Science.gov (United States)

Ge, Honghao; Ren, Fengli; Li, Jun; Han, Xiujun; Xia, Mingxu; Li, Jianguo

2017-03-01

A four-phase dendritic model was developed to predict the macrosegregation, shrinkage cavity, and porosity during solidification. In this four-phase dendritic model, some important factors, including dendritic structure for equiaxed crystals, melt convection, crystals sedimentation, nucleation, growth, and shrinkage of solidified phases, were taken into consideration. Furthermore, in this four-phase dendritic model, a modified shrinkage criterion was established to predict shrinkage porosity (microporosity) of a 55-ton industrial Fe-3.3 wt pct C ingot. The predicted macrosegregation pattern and shrinkage cavity shape are in a good agreement with experimental results. The shrinkage cavity has a significant effect on the formation of positive segregation in hot top region, which generally forms during the last stage of ingot casting. The dendritic equiaxed grains also play an important role on the formation of A-segregation. A three-dimensional laminar structure of A-segregation in industrial ingot was, for the first time, predicted by using a 3D case simulation.

Relation between Kitaev magnetism and structure in $\\alpha$-RuCl$_3$

OpenAIRE

Glamazda, A.; Lemmens, P.; Do, S. -H.; Kwon, Y. S.; Choi, K. -Y.

2017-01-01

Raman scattering has been employed to investigate lattice and magnetic excitations of the honeycomb Kitaev material $\\alpha$-RuCl$_3$ and its Heisenberg counterpart CrCl$_3$. Our phonon Raman spectra give evidence for a first-order structural transition from a monoclinic to a rhombohedral structure for both compounds. Significantly, only $\\alpha$-RuCl$_3$ features a large thermal hysteresis, consistent with the formation of a wide phase of coexistence. In the related temperature interval of $...

Molecular basis for nondeletion alpha-thalassemia in American blacks. Alpha 2(116GAG----UAG).

OpenAIRE

Liebhaber, S A; Coleman, M B; Adams, J G; Cash, F E; Steinberg, M H

1987-01-01

An American black woman was found to have the phenotype of moderately severe alpha-thalassemia normally associated with the loss of two to three alpha-globin genes despite an alpha-globin gene map that demonstrated the loss of only a single alpha-globin gene (-alpha/alpha alpha). Several individuals in her kindred with normal alpha-globin gene mapping studies (alpha alpha/alpha alpha) had mild alpha-thalassemia hematologic values consistent with the loss of one to two alpha-globin genes. Thes...

Confined trapped-alpha behavior in TFTR deuterium-tritium plasmas

International Nuclear Information System (INIS)

Medley, S.S.; Budny, R.V.; Redi, M.H.; Roquemore, A.L.; White, R.B.; Petrov, M.P.; Gorelenkov, N.N.

1997-10-01

Confined trapped-alpha energy spectra and differential radial density profiles in TFTR D-T plasmas are obtained with the Pellet Charge-eXchange (PCX) diagnostic which measures high energy (E α = 0.5--3.5 MeV), trapped alphas (v parallel /v = - 0.048) at a single time slice (Δt ∼ 1 msec) with a spatial resolution of Δr ∼ 5 cm. Tritons produced in D-D plasmas and RF-driven ion tails (H, 3 He or T) were also observed and energetic tritium ion tail measurements will be discussed. PCX alpha and triton energy spectra extending up to their birth energies were measured in the core of MHD-quiescent discharges where the expected classical slowing down and pitch angle scattering effects are not complicated by stochastic ripple diffusion and sawtooth activity. Both the shape of the measured alpha and triton energy distributions and their density ratios are in good agreement with TRANSP predictions, indicating that the PCX measurements are consistent with classical thermalization of the fusion-generated alphas and tritons. From calculations, these results set an upper limit on possible anomalous radial diffusion for trapped alphas of D α ≤ 0.01 m 2 s -1 . Outside the core, where the trapped alphas are influenced by stochastic ripple diffusion effects, the PCX measurements are consistent with the functional dependence of the Goldston-White-Boozer stochastic ripple threshold on the alpha energy and the q-profile. In the presence of strong sawtooth activity, the PCX diagnostic observes significant redistribution of the alpha signal radial profile wherein alphas are depleted in the core and redistributed to well outside the q = 1 radius, but apparently not beyond the energy-dependent stochastic ripple loss boundary

Numerical predictions of bubbly two-phase flows with OpenFOAM

International Nuclear Information System (INIS)

Michta, E.; Fu, K.; Anglart, H.; Angele, K.

2011-01-01

A new model for simulation of bubbly two-phase flows has been developed and implemented into an open-source Computational Fluid Dynamics (CFD) code OpenFOAM. The model employs the two-fluid framework with closure relationships for the interfacial momentum transfer. The bubble size is calculated based on the solution of the interfacial area concentration equations. The predictions are validated against a wide range of experimental data containing measured void fraction, the phasic velocity and the interfacial area concentration. The new model demonstrates the ability to capture the wall peaking of void fraction for small bubbles. The predicted levels of void fraction and phasic velocities are in good agreement with measured data. (author)

Clustering of galaxies near damped Lyman-alpha systems with (z) = 2.6

Science.gov (United States)

Wolfe, A. M

1993-01-01

The galaxy two-point correlation function, xi, at (z) = 2.6 is determined by comparing the number of Ly-alpha-emitting galaxies in narrowband CCD fields selected for the presence of damped L-alpha absorption to their number in randomly selected control fields. Comparisons between the presented determination of (xi), a density-weighted volume average of xi, and model predictions for (xi) at large redshifts show that models in which the clustering pattern is fixed in proper coordinates are highly unlikely, while better agreement is obtained if the clustering pattern is fixed in comoving coordinates. Therefore, clustering of Ly-alpha-emitting galaxies around damped Ly-alpha systems at large redshifts is strong. It is concluded that the faint blue galaxies are drawn from a parent population different from normal galaxies, the presumed offspring of damped Ly-alpha systems.

Echocardiographic phase imaging to predict reverse remodeling after cardiac resynchronization therapy.

Science.gov (United States)

Buss, Sebastian J; Humpert, Per M; Bekeredjian, Raffi; Hardt, Stefan E; Zugck, Christian; Schellberg, Dieter; Bauer, Alexander; Filusch, Arthur; Kuecherer, Helmut; Katus, Hugo A; Korosoglou, Grigorios

2009-05-01

The aim of our study was to investigate whether echocardiographic phase imaging (EPI) can predict response in patients who are considered for cardiac resynchronization therapy (CRT). CRT improves quality of life, exercise capacity, and outcome in patients with bundle-branch block and advanced heart failure. Previous studies used QRS duration to select patients for CRT; the accuracy of this parameter to predict functional recovery, however, is controversial. We examined 42 patients with advanced heart failure (New York Heart Association [NYHA] functional class III to IV, QRS duration >130 ms, and ejection fraction or=15% at 6 to 8 months of follow-up were defined as responders. All others were classified as nonresponders. The Ts-SD and the mean EPI-Index were related to Delta ESV (r = 0.43 for Ts-SD and r = 0.67 for mean EPI-Index, p < 0.01 for both), and both parameters yielded similar accuracy for the prediction of LV remodeling (area under the curve of 0.87 for TDI vs. 0.90 for EPI, difference between areas = 0.03, p = NS) and ejection fraction (EF) improvement (area under the curve of 0.87 for TDI vs. 0.93 for EPI, difference between areas = 0.06, p = NS). Furthermore, patients classified as responders by EPI (mean EPI-Index phase imaging can predict functional recovery, reverse LV remodeling, and clinical outcomes in patients who undergo CRT. EPI is a method that objectively and accurately quantifies LV dyssynchrony and seems to be noninferior to TDI for the prediction of reverse LV remodeling and functional recovery.

Prediction of pressure drop and CCFL breakdown in countercurrent two-phase flow

International Nuclear Information System (INIS)

Ostrogorsky, A.G.; Gay, R.R.; Lahey, R.T. Jr.

1983-01-01

A steady-state analytical has been developed to predict channel pressure drop as a function of inlet vapor flow rate and applied heat flux during conditions of countercurrent two-phase flow. The interfacial constitutive relations utilized are flow surface dependent and allow for the existence of either smooth or way liquid films. A computer code was developed to solve the analytical model. Predictions of Δp versus vapor flow rate were found to agree favorably with experimental data from adiabatic, air/water systems. In addition, the model was used to predict countercurrent flow conditions in heated channels characteristic of a BWR/4 nuclear reactor fuel assembly

The ALPHA project: A progress report

International Nuclear Information System (INIS)

Yadigaroglu, G.

1995-01-01

A review of the ALPHA project is presented, including a summary of progress and current status. The project comprises the experimental and analytical investigation of the long-term decay heat removal phenomena from the containment of the next generation of passive Advanced Light Water Reactors. In its present phase, the project is directed to the investigation of the Simplified Boiling Water Reactor (SBWR) Passive Containment Cooling system. The project includes separate-effects tests of containment phenomena (the LINX program). The effects of aerosols that may result from hypothetical severe accidents are also considered (the AIDA program). The construction and commissioning of the major ALPHA experimental facilities, PANDA, LINX-2 and AIDA is complete and the first series of tests are underway. Scaling studies have guided their design. Several small-scale experiments and studies have already produced valuable results

Two novel, putatively cell wall-associated and glycosylphosphatidylinositol-anchored alpha-glucanotransferase enzymes of aspergillus niger

NARCIS (Netherlands)

Kaaij, van der Rachel; Yuan, X.-L.; Franken, A.; Ram, A. F. J.; Punt, P. J.; Maarel, M.J.E.C. van der; Dijkhuizen, L.

In the genome sequence of Aspergillus niger CBS 513.88, three genes were identified with high similarity to fungal alpha-amylases. The protein sequences derived from these genes were different in two ways from all described fungal alpha-amylases: they were predicted to be

Anti-pp,. cap alpha cap alpha. and p. cap alpha. elastic scattering at high energies and Chou-Yang conjecture

Energy Technology Data Exchange (ETDEWEB)

Saleem, M.; Fazal-e-Aleem; Rifique, M.

1987-03-01

The recent experimental measurements for anti-pp and ..cap alpha cap alpha.. elastic scattering at high energies have shown that the Chou-Yang conjecture regarding the relationship between the electromagnetic and the hadronic form factor of a particle is only an approximation. A new ansatz has been proposed to obtain hadronic form factors of proton and the ..cap alpha..-particle. These form factors have been used to explain the various characteristics of anti-pp, ..cap alpha cap alpha.. and p..cap alpha.. elastic scattering at high energies.

Clinical and virological effects of high-dose recombinant interferon-alpha in disseminated AIDS-related Kaposi's sarcoma

NARCIS (Netherlands)

de Wit, R.; Schattenkerk, J. K.; Boucher, C. A.; Bakker, P. J.; Veenhof, K. H.; Danner, S. A.

1988-01-01

The effectiveness and antiretroviral activities of interferon-alpha in AIDS-related Kaposi's sarcoma was assessed in a non-randomised, phase-II clinical trial. 28 patients were treated with high-dose (27-36 MU) human recombinant interferon-alpha 2a subcutaneously every day for 8 weeks. In patients

A comprehensive alpha-heating model for inertial confinement fusion

Science.gov (United States)

Christopherson, A. R.; Betti, R.; Bose, A.; Howard, J.; Woo, K. M.; Campbell, E. M.; Sanz, J.; Spears, B. K.

2018-01-01

A comprehensive model is developed to study alpha-heating in inertially confined plasmas. It describes the time evolution of a central low-density hot spot confined by a compressible shell, heated by fusion alphas, and cooled by radiation and thermal losses. The model includes the deceleration, stagnation, and burn phases of inertial confinement fusion implosions, and is valid for sub-ignited targets with ≤10 × amplification of the fusion yield from alpha-heating. The results of radiation-hydrodynamic simulations are used to derive realistic initial conditions and dimensionless parameters for the model. It is found that most of the alpha energy (˜90%) produced before bang time is deposited within the hot spot mass, while a small fraction (˜10%) drives mass ablation off the inner shell surface and its energy is recycled back into the hot spot. Of the bremsstrahlung radiation emission, ˜40% is deposited in the hot spot, ˜40% is recycled back in the hot spot by ablation off the shell, and ˜20% leaves the hot spot. We show here that the hot spot, shocked shell, and outer shell trajectories from this analytical model are in good agreement with simulations. A detailed discussion of the effect of alpha-heating on the hydrodynamics is also presented.

High-temperature phase transformation in Cr added TiAl base alloy

Energy Technology Data Exchange (ETDEWEB)

Abe, E.; Niinobe, K.; Nobuki, M.; Nakamura, M.; Tsujimoto, T.

1999-07-01

The authors have investigated a microstructure evolution of a Ti-48Al-3.5Cr (in at.%) alloy at high-temperatures ({gt} 1,473K). In the alloy annealed at 1673K for 1.8ks, followed by air-cooling, a characteristic microstructure with a feathery fashion was uniformly formed. From a cooling-rate-controlling study, it was found that formation of the feathery structure is accomplished during continuous cooling from 1673K to 1573K, within the {alpha} + {gamma} two-phase region. Transmission electron microscopy revealed that the feathery structure is composed of lamellar colonies (5--10{micro}m) which are crystallographically tilted slightly (a few degree) with their neighbors. A surprising fact is that lamellae in each colony are mostly the {gamma} phase with few {alpha}{sub 2} phase less than 5% in volume. This suggests that the feathery structure is a metastable product and has not resulted from the {alpha} {r{underscore}arrow} {alpha} + {gamma} transformation above 1,573 K. Instead, the feathery structure formation should be attributed to the non-equilibrium {alpha} {r{underscore}arrow} {gamma} transformation which occurs at high-temperatures with a small degree of supercooling. The authors discuss this interesting phase transformation in terms of the {alpha} {r{underscore}arrow} {gamma} massive transformation, based on the continuous-cooling-transformation (CCT) diagram constructed for the present alloy.

Nonlinear optical properties of TeO$_2$ crystalline phases from first principles

OpenAIRE

Berkaine, Nabil; Orhan, Emmanuelle; Masson, Olivier; Thomas, Philippe; Junquera, Javier

2010-01-01

We have computed second and third nonlinear optical susceptibilities of two crystalline bulk tellurium oxide polymorphs: $\\alpha$-TeO$_{2}$ (the most stable crystalline bulk phase) and $\\gamma$-TeO$_{2}$ (the crystalline phase that ressembles the more to the glass phase. Third order nonlinear susceptibilities of the crystalline phases are two orders of magnitude larger than $\\alpha$-SiO$_{2}$ cristoballite, thus extending the experimental observations on glasses to the case of crystalline com...

Mid- and long-term runoff predictions by an improved phase-space reconstruction model

International Nuclear Information System (INIS)

Hong, Mei; Wang, Dong; Wang, Yuankun; Zeng, Xiankui; Ge, Shanshan; Yan, Hengqian; Singh, Vijay P.

2016-01-01

In recent years, the phase-space reconstruction method has usually been used for mid- and long-term runoff predictions. However, the traditional phase-space reconstruction method is still needs to be improved. Using the genetic algorithm to improve the phase-space reconstruction method, a new nonlinear model of monthly runoff is constructed. The new model does not rely heavily on embedding dimensions. Recognizing that the rainfall–runoff process is complex, affected by a number of factors, more variables (e.g. temperature and rainfall) are incorporated in the model. In order to detect the possible presence of chaos in the runoff dynamics, chaotic characteristics of the model are also analyzed, which shows the model can represent the nonlinear and chaotic characteristics of the runoff. The model is tested for its forecasting performance in four types of experiments using data from six hydrological stations on the Yellow River and the Yangtze River. Results show that the medium-and long-term runoff is satisfactorily forecasted at the hydrological stations. Not only is the forecasting trend accurate, but also the mean absolute percentage error is no more than 15%. Moreover, the forecast results of wet years and dry years are both good, which means that the improved model can overcome the traditional ‘‘wet years and dry years predictability barrier,’’ to some extent. The model forecasts for different regions are all good, showing the universality of the approach. Compared with selected conceptual and empirical methods, the model exhibits greater reliability and stability in the long-term runoff prediction. Our study provides a new thinking for research on the association between the monthly runoff and other hydrological factors, and also provides a new method for the prediction of the monthly runoff. - Highlights: • The improved phase-space reconstruction model of monthly runoff is established. • Two variables (temperature and rainfall) are incorporated

Mid- and long-term runoff predictions by an improved phase-space reconstruction model

Energy Technology Data Exchange (ETDEWEB)

Hong, Mei [Research Center of Ocean Environment Numerical Simulation, Institute of Meteorology and oceanography, PLA University of Science and Technology, Nanjing (China); Wang, Dong, E-mail: wangdong@nju.edu.cn [Key Laboratory of Surficial Geochemistry, Ministry of Education, Department of Hydrosciences, School of Earth Sciences and Engineering, Collaborative Innovation Center of South China Sea Studies, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing 210093 (China); Wang, Yuankun; Zeng, Xiankui [Key Laboratory of Surficial Geochemistry, Ministry of Education, Department of Hydrosciences, School of Earth Sciences and Engineering, Collaborative Innovation Center of South China Sea Studies, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing 210093 (China); Ge, Shanshan; Yan, Hengqian [Research Center of Ocean Environment Numerical Simulation, Institute of Meteorology and oceanography, PLA University of Science and Technology, Nanjing (China); Singh, Vijay P. [Department of Biological and Agricultural Engineering Zachry Department of Civil Engineering, Texas A & M University, College Station, TX 77843 (United States)

2016-07-15

In recent years, the phase-space reconstruction method has usually been used for mid- and long-term runoff predictions. However, the traditional phase-space reconstruction method is still needs to be improved. Using the genetic algorithm to improve the phase-space reconstruction method, a new nonlinear model of monthly runoff is constructed. The new model does not rely heavily on embedding dimensions. Recognizing that the rainfall–runoff process is complex, affected by a number of factors, more variables (e.g. temperature and rainfall) are incorporated in the model. In order to detect the possible presence of chaos in the runoff dynamics, chaotic characteristics of the model are also analyzed, which shows the model can represent the nonlinear and chaotic characteristics of the runoff. The model is tested for its forecasting performance in four types of experiments using data from six hydrological stations on the Yellow River and the Yangtze River. Results show that the medium-and long-term runoff is satisfactorily forecasted at the hydrological stations. Not only is the forecasting trend accurate, but also the mean absolute percentage error is no more than 15%. Moreover, the forecast results of wet years and dry years are both good, which means that the improved model can overcome the traditional ‘‘wet years and dry years predictability barrier,’’ to some extent. The model forecasts for different regions are all good, showing the universality of the approach. Compared with selected conceptual and empirical methods, the model exhibits greater reliability and stability in the long-term runoff prediction. Our study provides a new thinking for research on the association between the monthly runoff and other hydrological factors, and also provides a new method for the prediction of the monthly runoff. - Highlights: • The improved phase-space reconstruction model of monthly runoff is established. • Two variables (temperature and rainfall) are incorporated

Three-phase Bone Scintigraphy Can Predict the Analgesic Efficacy of Ketamine Therapy in CRPS.

Science.gov (United States)

Sorel, Marc; Beatrix, Jacques-Christian; Locko, Blanche; Armessen, Catherine; Domec, Anne-Marie; Lecompte, Otilia; Boucheneb, Sofiane; Harache, Benoit; Robert, Jacques; Lefaucheur, Jean-Pascal

2018-03-13

The efficacy of ketamine in relieving complex regional pain syndrome (CRPS) lacks predictive factors. The value of three-phase bone scintigraphy (TPBS) was assessed or this purpose. TPBS was performed in 105 patients with unilateral, focal CRPS of type 1 before 5 days of ketamine infusions. Tracer uptake was measured in the region of interest concerned by CRPS and the contralateral homologous region. For the three scintigraphic phases (vascular, tissular, and bone phases), an asymmetry ratio of fixation was calculated between the affected and the unaffected sides (VPr, TPr, and BPr). Ketamine efficacy was assessed on pain intensity scores. Ketamine-induced pain relief did not correlate with VPr, TPr, and BPr, but with the ratios of these ratios: BPr/TPr (r=0.32, P=0.009), BPr/VPr (r=0.34, P=0.005), and TPr/VPr (r=0.23, P=0.02). The optimum cut-off value for predicting the response to ketamine therapy was >1.125 for BPr/TPr, >1.075 for BPr/VPr, and >0.935 for TPr/VPr. The combination of increased values of BPr/TPr, BPr/VPr, and TPr/VPr was extremely significantly associated with ketamine therapy outcome. The relative hyperfixation of the radioactive tracer in the limb region concerned by CRPS in phases 2 and 3 versus phase 1 of TPBS correlated positively to the analgesic efficacy of ketamine. This study shows for the first time the potential predictive value of TPBS regarding ketamine therapy outcome. In addition, these results suggest that the analgesic action of ketamine is not restricted to "central" mechanisms, but may also involve "peripheral" mechanisms related to tissue inflammation and bone remodeling.

Predicting phase shift effects for vibrating fluid-conveying pipes due to Coriolis forces and fluid pulsation

DEFF Research Database (Denmark)

Enz, Stephanie; Thomsen, Jon Juel

2011-01-01

to improve accuracy, precision, and robustness of CFMs. A simple mathematical model of a fluid-conveying pipe is formulated and the effect of pulsating fluid flow is analyzed using a multiple time scaling perturbation analysis. The results are simple analytical predictions for the transverse pipe...... and uncontrolled during CFM operation by feedback control. The analytical predictions offer an immediate insight into how fluid pulsation affects phase shift, which is a quantity measured by CFMs to estimate the mass flow, and lead to hypotheses for more complex geometries, i.e. industrial CFMs. The validity...... displacement and approximate axial shift in vibration phase. The analytical predictions are tested against pure numerical solution using representative examples, showing good agreement. Fluid pulsations are predicted not to influence CFM accuracy, since proper signal filtering is seen to allow...

THERMAL PHASE VARIATIONS OF WASP-12b: DEFYING PREDICTIONS

Energy Technology Data Exchange (ETDEWEB)

Cowan, Nicolas B.; Shekhtman, Louis M. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2131 Tech Dr, Evanston, IL 60208 (United States); Machalek, Pavel [SETI Institute, 189 Bernardo Ave., Suite 100, Mountain View, CA 94043 (United States); Croll, Bryce [Department of Astronomy and Astrophysics, University of Toronto, 50 George St., Toronto, ON, M5S 3H4 (Canada); Burrows, Adam [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 05844 (United States); Deming, Drake [Planetary Systems Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Greene, Tom [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Hora, Joseph L., E-mail: n-cowan@northwestern.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

2012-03-01

We report Warm Spitzer full-orbit phase observations of WASP-12b at 3.6 and 4.5 {mu}m. This extremely inflated hot Jupiter is thought to be overflowing its Roche lobe, undergoing mass loss and accretion onto its host star, and has been claimed to have a C/O ratio in excess of unity. We are able to measure the transit depths, eclipse depths, thermal and ellipsoidal phase variations at both wavelengths. The large-amplitude phase variations, combined with the planet's previously measured dayside spectral energy distribution, are indicative of non-zero Bond albedo and very poor day-night heat redistribution. The transit depths in the mid-infrared-(R{sub p} /R{sub *}){sup 2} = 0.0123(3) and 0.0111(3) at 3.6 and 4.5 {mu}m, respectively-indicate that the atmospheric opacity is greater at 3.6 than at 4.5 {mu}m, in disagreement with model predictions, irrespective of C/O ratio. The secondary eclipse depths are consistent with previous studies: F{sub day}/F{sub *} = 0.0038(4) and 0.0039(3) at 3.6 and 4.5 {mu}m, respectively. We do not detect ellipsoidal variations at 3.6 {mu}m, but our parameter uncertainties-estimated via prayer-bead Monte Carlo-keep this non-detection consistent with model predictions. At 4.5 {mu}m, on the other hand, we detect ellipsoidal variations that are much stronger than predicted. If interpreted as a geometric effect due to the planet's elongated shape, these variations imply a 3:2 ratio for the planet's longest:shortest axes and a relatively bright day-night terminator. If we instead presume that the 4.5 {mu}m ellipsoidal variations are due to uncorrected systematic noise and we fix the amplitude of the variations to zero, the best-fit 4.5 {mu}m transit depth becomes commensurate with the 3.6 {mu}m depth, within the uncertainties. The relative transit depths are then consistent with a solar composition and short scale height at the terminator. Assuming zero ellipsoidal variations also yields a much deeper 4.5 {mu}m eclipse depth

Increase in posterior alpha activity during rehearsal predicts successful long-term memory formation of word sequences.

Science.gov (United States)

Meeuwissen, Esther B; Takashima, Atsuko; Fernández, Guillén; Jensen, Ole

2011-12-01

It is becoming increasingly clear that demanding cognitive tasks rely on an extended network engaging task-relevant areas and, importantly, disengaging task-irrelevant areas. Given that alpha activity (8-12 Hz) has been shown to reflect the disengagement of task-irrelevant regions in attention and working memory tasks, we here ask if alpha activity plays a related role for long-term memory formation. Subjects were instructed to encode and maintain the order of word sequences while the ongoing brain activity was recorded using magnetoencephalography (MEG). In each trial, three words were presented followed by a 3.4 s rehearsal interval. Considering the good temporal resolution of MEG this allowed us to investigate the word presentation and rehearsal interval separately. The sequences were grouped in trials where word order either could be tested immediately (working memory trials; WM) or later (LTM trials) according to instructions. Subjects were tested on their ability to retrieve the order of the three words. The data revealed that alpha power in parieto-occipital regions was lower during word presentation compared to rehearsal. Our key finding was that parieto-occipital alpha power during the rehearsal period was markedly stronger for successfully than unsuccessfully encoded LTM sequences. This subsequent memory effect demonstrates that high posterior alpha activity creates an optimal brain state for successful LTM formation possibly by actively reducing parieto-occipital activity that might interfere with sequence encoding. Copyright © 2010 Wiley Periodicals, Inc.

Numerical Predictions of Bubbly Two-Phase Flows with OpenFOAM

Directory of Open Access Journals (Sweden)

Edouard Michta

2012-12-01

Full Text Available A new model for simulation of bubbly two-phase flows has been developed and implemented into an open-source Computational Fluid Dynamics (CFD code OpenFOAM. The model employs the two-fluid framework with closure relationships for the interfacial momentum transfer. The bubble size is calculated based on the solution of the transport equation of the interfacial area concentration. The predictions are validated against selected data obtained in the DEDALE experiment and containing the measured void fraction, the phasic velocities and the interfacial area concentration. In general, good agreement between calculated and measured data is demonstrated; however, the relative phasic velocity is systematically over-predicted. The levels of void fraction and the observed wall void peaking are well captured in the calculations.

Investigation of the Pygmy Dipole Resonance in (alpha, alpha 'gamma) coincidence experiments

NARCIS (Netherlands)

Savran, D.; Babilon, M.; van den Berg, A. M.; Harakeh, M. N.; Hasper, J.; Wortche, H. J.; Zilges, A.

2007-01-01

We report on first results from experiments using the (alpha, alpha'gamma) reaction at E alpha = 136 MeV to investigate bound electric dipole (El) excitations building the so-called Pygmy Dipole Resonance (PDR) in the semi-magic nucleus Ce-140. The method of (alpha, alpha'gamma) allows the

[beta]-hexosaminidase isozymes from cells cotransfected with [alpha] and [beta] cDNA constructs: Analysis of the [alpha]-subunit missense mutation associated with the adult form of Tay-Sachs disease

Energy Technology Data Exchange (ETDEWEB)

Brown, C.A.; Mahuran, D.J. (Univ. of Toronto (Canada))

1993-08-01

In vitro mutagenesis and transient expression in COS cells has been used to associate a missense mutation with a clinical or biochemical phenotype. Mutations affecting the [alpha]-subunit of [beta]-hexosaminidase A ([alpha][beta]) (E.C.3.2.1.52) result in Tay-Sachs disease. Because hexosaminidase A is heterodimeric, analysis of [alpha]-chain mutations is not straightforward. The authors examine three approaches utilizing previously identified mutations affecting [alpha]-chain folding. These involve transfection of (1) the [alpha] cDNA alone; (2) a [beta] cDNA construct encoding a [beta]-subunit substituted at a position homologous to that of the [alpha]-subunit, and (3) both [alpha] and [beta] cDNAs. The latter two procedures amplified residual activity levels over that of patient samples, an effect not previously found with mutations affecting an [open quotes]active[close quotes] [alpha]Arg residue. This effect may help to discriminate between protein-folding and active-site mutations. The authors conclude that, with proper controls, the latter method of cotransfection can be used to evaluate the effects and perhaps to predict the clinical course of some [alpha]-chain mutations. Using this technique, they demonstrate that the adult-onset Tay-Sachs mutation, [alpha]Gly[yields]Ser[sup 269], does not directly affect [alpha][beta] dimerization but exerts an indirect effect on the dimer through destabilizing the folded [alpha]-subunit at physiological temperatures. Two other [alpha] mutations linked to more severe phenotypes appear to inhibit the initial folding of the subunit. 36 refs., 2 figs., 5 tabs.

Increased virulence and competitive advantage of a/alpha over a/a or alpha/alpha offspring conserves the mating system of Candida albicans.

Science.gov (United States)

Lockhart, Shawn R; Wu, Wei; Radke, Joshua B; Zhao, Rui; Soll, David R

2005-04-01

The majority of Candida albicans strains in nature are a/alpha and must undergo homozygosis to a/a or alpha/alpha to mate. Here we have used a mouse model for systemic infection to test the hypothesis that a/alpha strains predominate in nature because they have a competitive advantage over a/a and alpha/alpha offspring in colonizing hosts. Single-strain injection experiments revealed that a/alpha strains were far more virulent than either their a/a or alpha/alpha offspring. When equal numbers of parent a/alpha and offspring a/a or alpha/alpha cells were co-injected, a/alpha always exhibited a competitive advantage at the time of extreme host morbidity or death. When equal numbers of an engineered a/a/alpha2 strain and its isogenic a/a parent strain were co-injected, the a/a/alpha2 strain exhibited a competitive advantage at the time of host morbidity or death, suggesting that the genotype of the mating-type (MTL) locus, not associated genes on chromosome 5, provides a competitive advantage. We therefore propose that heterozygosity at the MTL locus not only represses white-opaque switching and genes involved in the mating process, but also affects virulence, providing a competitive advantage to the a/alpha genotype that conserves the mating system of C. albicans in nature.

A Phase 3 Placebo-Controlled, Double Blind, Multi-Site Trial of the alpha-2-adrenergic Agonist, Lofexidine, for Opioid Withdrawal

Science.gov (United States)

Yu, Elmer; Miotto, Karen; Akerele, Evaristo; Montgomery, Ann; Elkashef, Ahmed; Walsh, Robert; Montoya, Ivan; Fischman, Marian W.; Collins, Joseph; McSherry, Frances; Boardman, Kathy; Davies, David K.; O’Brien, Charles P.; Ling, Walter; Kleber, Herbert; Herman, Barbara H.

2008-01-01

Context Lofexidine is an alpha-2-A noradrenergic receptor agonist that is approved in the United Kingdom for the treatment of opioid withdrawal symptoms. Lofexidine has been reported to have more significant effects on decreasing opioid withdrawal symptoms with less hypotension than clonidine. Objective To demonstrate that lofexidine is well tolerated and effective in the alleviation of observationally-defined opioid withdrawal symptoms in opioid dependent individuals undergoing medically supervised opioid detoxification as compared to placebo. Design An inpatient, Phase 3, placebo-controlled, double blind, randomized multi-site trial with three phases: (1) Opioid Agonist Stabilization Phase (days 1–3), (2) Detoxification/Medication or Placebo Phase (days 4–8), and (3) Post Detoxification/Medication Phase (days 9–11). Subjects Sixty-eight opioid dependent subjects were enrolled at three sites with 35 randomized to lofexidine and 33 to placebo. Main Outcome Measure Modified Himmelsbach Opiate Withdrawal Scale (MHOWS) on study day 5 (2nd opioid detoxification treatment day). Results Due to significant findings, the study was terminated early. On the study day 5 MHOWS, subjects treated with lofexidine had significantly lower scores (equating to fewer/less severe withdrawal symptoms) than placebo subjects (Least squares means 19.5 ± 2.1 versus 30.9 ± 2.7; p=0.0019). Lofexidine subjects had significantly better retention in treatment than placebo subjects (38.2% versus 15.2%; Log rank test p=0.01). Conclusions Lofexidine is well tolerated and more efficacious than placebo for reducing opioid withdrawal symptoms in inpatients undergoing medically supervised opioid detoxification. Trial Registration trial registry name A Phase 3 Placebo-Controlled, Double-Blind Multi-Site Trial of Lofexidine for Opiate Withdrawal, registration number NCT00032942, URL for the registry http://clinicaltrials.gov/ct/show/NCT00032942?order=4. PMID:18508207

Nonlinear Prediction As A Tool For Determining Parameters For Phase Space Reconstruction In Meteorology

Science.gov (United States)

Miksovsky, J.; Raidl, A.

Time delays phase space reconstruction represents one of useful tools of nonlinear time series analysis, enabling number of applications. Its utilization requires the value of time delay to be known, as well as the value of embedding dimension. There are sev- eral methods how to estimate both these parameters. Typically, time delay is computed first, followed by embedding dimension. Our presented approach is slightly different - we reconstructed phase space for various combinations of mentioned parameters and used it for prediction by means of the nearest neighbours in the phase space. Then some measure of prediction's success was computed (correlation or RMSE, e.g.). The position of its global maximum (minimum) should indicate the suitable combination of time delay and embedding dimension. Several meteorological (particularly clima- tological) time series were used for the computations. We have also created a MS- Windows based program in order to implement this approach - its basic features will be presented as well.

Quasi-closed phase forward-backward linear prediction analysis of speech for accurate formant detection and estimation.

Science.gov (United States)

Gowda, Dhananjaya; Airaksinen, Manu; Alku, Paavo

2017-09-01

Recently, a quasi-closed phase (QCP) analysis of speech signals for accurate glottal inverse filtering was proposed. However, the QCP analysis which belongs to the family of temporally weighted linear prediction (WLP) methods uses the conventional forward type of sample prediction. This may not be the best choice especially in computing WLP models with a hard-limiting weighting function. A sample selective minimization of the prediction error in WLP reduces the effective number of samples available within a given window frame. To counter this problem, a modified quasi-closed phase forward-backward (QCP-FB) analysis is proposed, wherein each sample is predicted based on its past as well as future samples thereby utilizing the available number of samples more effectively. Formant detection and estimation experiments on synthetic vowels generated using a physical modeling approach as well as natural speech utterances show that the proposed QCP-FB method yields statistically significant improvements over the conventional linear prediction and QCP methods.

Alpha cluster states in light nuclei populated through the (6Li,d) reaction

Energy Technology Data Exchange (ETDEWEB)

Borello-Lewin, Thereza; Rodrigues, M.R.D.; Horodynski-Matsushigue, L.B.; Duarte, J.L.M.; Rodrigues, C.L.; Souza, M.A. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica; Cunsolo, A.; Cappuzzello, F. [Universita di Catania (Italy). Istituto Nazionale di Fisica Nucleare. Lab. Nazionali del Sud; Ukita, Gilberto Mitsuo [Universidade de Santo Amaro (UNISA), Sao Paulo, SP (Brazil). Fac. de Psicologia

2011-07-01

Full text: The alpha cluster correlation is an important concept in the nuclear physics of light nuclei. The main purpose of the research program in progress is the investigation of the alpha clustering phenomenon in (x{alpha}) and(x{alpha}+{nu}) nuclei through the ({sup 6}Li,d) alpha transfer reaction. In fact, there is scarce experimental information on the subject, in particular associated with resonant states predicted near (x{alpha}) and (x{alpha}+{nu}) thresholds. Measurements of the {sup 12},{sup 13}C({sup 6}Li,d) {sup 16},{sup 17}O reactions, at an incident energy of 25.5 MeV, have been performed employing the Sao Paulo Pelletron-Enge Split-Pole facility and the nuclear emulsion detection technique. The work is under way and an experimental energy resolution of 30 keV was obtained. Near the (4{alpha}) breakup threshold in {sup 16}O, three narrow alpha resonances, not previously measured, were detected, revealing important {alpha} + {sup 12}C(G.S.) components. One of these resonances corresponds to the known 0{sup +} state at 15.1 MeV[5] of excitation that has probably, according to Funaki et al., the gas like configuration of the 4{alpha} condensate state, with a very dilute density and a large component of {alpha} + {sup 12}C(Hoyle) configuration. As was already mentioned, our experimental information points to the necessity of including the {alpha} + {sup 12}C(G.S.) component in the wave function. (author)

A new procedure for coupling antibody to paper discs for radioimmunoassay: application to the determination of alpha-fetoprotein

International Nuclear Information System (INIS)

Sasaki, T.; Tsukada, Y.; Hirai, H.

1983-01-01

Horse anti-alpha-fetoprotein was coupled to CM-cellulose discs by a modified carbodiimide reaction. The resulting coupled CM-discs were used in solid-phase radioimmunoassay of human alpha-fetoprotein. The sensitivity of these discs and conventional BrCN activated filter paper discs coupled anti-alpha-fetoprotein was approximately the same. A fair correlation between the alpha-fetoprotein levels determined by both methods was observed. The coupling procedure with carbodiimide is simple and the use of hazardous BrCN is eliminated. (Auth.)

THE LYMAN ALPHA REFERENCE SAMPLE: EXTENDED LYMAN ALPHA HALOS PRODUCED AT LOW DUST CONTENT

Energy Technology Data Exchange (ETDEWEB)

Hayes, Matthew [Universite de Toulouse, UPS-OMP, IRAP, Toulouse (France); Oestlin, Goeran; Duval, Florent; Guaita, Lucia; Melinder, Jens; Sandberg, Andreas [Department of Astronomy, Oskar Klein Centre, Stockholm University, AlbaNova University Centre, SE-106 91 Stockholm (Sweden); Schaerer, Daniel [CNRS, IRAP, 14, avenue Edouard Belin, F-31400 Toulouse (France); Verhamme, Anne; Orlitova, Ivana [Geneva Observatory, University of Geneva, 51 Chemin des Maillettes, CH-1290 Versoix (Switzerland); Mas-Hesse, J. Miguel; Oti-Floranes, Hector [Centro de Astrobiologia (CSIC-INTA), Departamento de Astrofisica, POB 78, 28691 Villanueva de la Canada (Spain); Adamo, Angela [Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany); Atek, Hakim [Laboratoire d' Astrophysique, Ecole Polytechnique Federale de Lausanne (EPFL), Observatoire, CH-1290 Sauverny (Switzerland); Cannon, John M. [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Herenz, E. Christian [Leibniz-Institut fuer Astrophysik (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany); Kunth, Daniel [Institut d' Astrophysique de Paris, UMR 7095 CNRS and UPMC, 98 bis Bd Arago, F-75014 Paris (France); Laursen, Peter, E-mail: matthew@astro.su.se [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark)

2013-03-10

We report on new imaging observations of the Lyman alpha emission line (Ly{alpha}), performed with the Hubble Space Telescope, that comprise the backbone of the Lyman alpha Reference Sample. We present images of 14 starburst galaxies at redshifts 0.028 < z < 0.18 in continuum-subtracted Ly{alpha}, H{alpha}, and the far ultraviolet continuum. We show that Ly{alpha} is emitted on scales that systematically exceed those of the massive stellar population and recombination nebulae: as measured by the Petrosian 20% radius, R{sub P20}, Ly{alpha} radii are larger than those of H{alpha} by factors ranging from 1 to 3.6, with an average of 2.4. The average ratio of Ly{alpha}-to-FUV radii is 2.9. This suggests that much of the Ly{alpha} light is pushed to large radii by resonance scattering. Defining the Relative Petrosian Extension of Ly{alpha} compared to H{alpha}, {xi}{sub Ly{alpha}} = R {sup Ly{alpha}}{sub P20}/R {sup H{alpha}}{sub P20}, we find {xi}{sub Ly{alpha}} to be uncorrelated with total Ly{alpha} luminosity. However, {xi}{sub Ly{alpha}} is strongly correlated with quantities that scale with dust content, in the sense that a low dust abundance is a necessary requirement (although not the only one) in order to spread Ly{alpha} photons throughout the interstellar medium and drive a large extended Ly{alpha} halo.

TNF-alpha-308G>A polymorphism and the risk of familial CAD in a Pakistani population.

Science.gov (United States)

Hussain, Sabir; Iqbal, Tahir; Javed, Qamar

2015-01-01

A case-control and trio-families study was performed to establish a potential association between TNF-alpha gene promoter SNPs at -308 and -238, and occurrence of CAD in a Pakistani population. In the first phase, 150 patients and 150 controls were enrolled in the case-control association study. In the second phase, heritability of susceptible alleles was investigated from 88 trio-families with CAD affected offspring. Biochemical analysis of lipids and hs-CRP was carried out spectrophotometrically, while serum TNF-alpha concentrations were determined by enzyme-linked immunosorbent assay. Genotyping of the TNF-alpha SNPs were determined by PCR-RFLP method. Elevated serum TNF-alpha and hs-CRP were observed from CAD vs. controls (PA polymorphism in case-control study revealed that the said SNP was significantly associated with the increased risk of CAD. The findings demonstrated a significant link between the TNF-alpha variant allele A at -308 and CAD (P=0.0035), whereas the -238 SNP was not associated with the disease. Haplotype A-G of the TNF-alpha gene at -308G>A and -238G>A showed higher frequency in the patient group compared with controls (PA polymorphism is associated with CAD in the study population. Furthermore, for the first time, we showed that the TNF-alpha-308A allele was significantly associated with the familial CAD in our high risk population. Copyright © 2014. Published by Elsevier Inc.

Long-range synchronization and local desynchronization of alpha oscillations during visual short-term memory retention in children.

Science.gov (United States)

Doesburg, Sam M; Herdman, Anthony T; Ribary, Urs; Cheung, Teresa; Moiseev, Alexander; Weinberg, Hal; Liotti, Mario; Weeks, Daniel; Grunau, Ruth E

2010-04-01

Local alpha-band synchronization has been associated with both cortical idling and active inhibition. Recent evidence, however, suggests that long-range alpha synchronization increases functional coupling between cortical regions. We demonstrate increased long-range alpha and beta band phase synchronization during short-term memory retention in children 6-10 years of age. Furthermore, whereas alpha-band synchronization between posterior cortex and other regions is increased during retention, local alpha-band synchronization over posterior cortex is reduced. This constitutes a functional dissociation for alpha synchronization across local and long-range cortical scales. We interpret long-range synchronization as reflecting functional integration within a network of frontal and visual cortical regions. Local desynchronization of alpha rhythms over posterior cortex, conversely, likely arises because of increased engagement of visual cortex during retention.

KINETIC-ANALYSIS OF SHORT-TERM EFFECTS OF ALPHA-AGONISTS ON GLUCONEOGENESIS IN ISOLATED RAT HEPATOCYTES

NARCIS (Netherlands)

Leverve, X. M.; Groen, A. K.; Verhoeven, A. J.; Tager, J. M.

1985-01-01

Isolated hepatocytes from fasted rats were perifused with glycerol as gluconeogenic substrate. Stimulation of gluconeogenesis with phenylephrine (10(-5) M) as alpha-adrenergic agonist consisted of two distinct phases. The first phase was a transient stimulation of gluconeogenesis and was accompanied

Design, synthesis, and evaluation of an alpha-helix mimetic library targeting protein-protein interactions.

Science.gov (United States)

Shaginian, Alex; Whitby, Landon R; Hong, Sukwon; Hwang, Inkyu; Farooqi, Bilal; Searcey, Mark; Chen, Jiandong; Vogt, Peter K; Boger, Dale L

2009-04-22

The design and solution-phase synthesis of an alpha-helix mimetic library as an integral component of a small-molecule library targeting protein-protein interactions are described. The iterative design, synthesis, and evaluation of the candidate alpha-helix mimetic was initiated from a precedented triaryl template and refined by screening the designs for inhibition of MDM2/p53 binding. Upon identifying a chemically and biologically satisfactory design and consistent with the screening capabilities of academic collaborators, the corresponding complete library was assembled as 400 mixtures of 20 compounds (20 x 20 x 20-mix), where the added subunits are designed to mimic all possible permutations of the naturally occurring i, i + 4, i + 7 amino acid side chains of an alpha-helix. The library (8000 compounds) was prepared using a solution-phase synthetic protocol enlisting acid/base liquid-liquid extractions for purification on a scale that insures its long-term availability for screening campaigns. Screening of the library for inhibition of MDM2/p53 binding not only identified the lead alpha-helix mimetic upon which the library was based, but also suggests that a digestion of the initial screening results that accompany the use of such a comprehensive library can provide insights into the nature of the interaction (e.g., an alpha-helix mediated protein-protein interaction) and define the key residues and their characteristics responsible for recognition.

Synthesis and antimicrobial evaluation of new 3-alkyl/aryl-2-[((alpha,alpha-diphenyl-alpha-hydroxy)acetyl)hydrazono]-5-methyl-4-thiazolidinones.

Science.gov (United States)

Güzeldemirci, Nuray Ulusoy; Ilhan, Eser; Küçükbasmaci, Omer; Satana, Dilek

2010-01-01

New 4-thiazolidinone derivatives of benzilic acid (alpha,alpha-diphenyl-alpha-hydroxyacetic acid) have been synthesized and evaluated for antibacterial and antifungal activities. The reaction of 1- (alpha,alpha-diphenyl-alpha-hydroxy)acetyl-4-alkyl/arylthiosemicarbazides with ethyl 2-bromopropionate gave 3-alkyl/aryl-2-[((alpha,alpha-diphenyl-alpha-hydroxy)acetyl)hydrazono]-5-methyl-4-thiazolidinone derivatives. Their antibacterial and antifungal activities were evaluated against S. aureus ATCC 29213, P. aeruginosa ATCC 27853, E. coli ATCC 25922, C. albicans ATCC 10231, C. parapsilosis ATCC 22019, C. krusei ATCC 6258, T. mentagrophytes var. erinacei NCPF 375, M. gypseum NCPF 580 and T. tonsurans NCPF 245. 3e, 3f, 3g and 3h showed the highest antibacterial activity. Particularly 3a and 3e showed the highest antifungal activities against C. parapsilosis ATCC 22019, T. tonsurans NCPF 245 and M. gypseum NCPF 580.

An eigenstrain approach to predict phase transformation and self-accommodation in partially stabilized zirconia

International Nuclear Information System (INIS)

Hensl, Th.; Mühlich, U.; Budnitzki, M.; Kuna, M.

2015-01-01

Highlights: • Analytical model to predict phase transformation in PSZ is developed. • Analytical model to predict number of twins in monoclinic inclusions in PSZ. • Models consider inclusions size, shape, temperature, remote loading and surface energy. - Abstract: This work focuses on micromechanical modeling of the tetragonal to monoclinic phase transformation (t–m transformation) in partially stabilized zirconia (PSZ). Tetragonal particles dispersed in a cubic matrix may transform into the monoclinic phase under sufficiently high mechanical loading or if the material is cooled down below a critical temperature. This phase transformation is supposed to be responsible for the so called transformation toughening effect of PSZ. The transformation is usually accompanied by a self-accommodation process, which reduces the occurring eigenstresses in the surrounding matrix. The influences of particle size and geometry, chemical driving force, temperature, surface energy and remote loading on the t–m transformation are estimated by a thermostatic approach. We assume, that transformations occur, once the Gibbs free energy of the transformed equilibrium state is lower than that of the untransformed reference state. To obtain an analytical solution, the microstructure is modeled as an inclusion of rectangular cross section, restrained by an infinite elastic matrix, under plane strain conditions. The developed model for phase transformation captures the well-known size and temperature dependencies. Furthermore, it indicates a significant influence of the particle geometry, that large aspect ratios of the inclusion’s cross section lower the trigger stress for phase transformation

Variability of the Lyman alpha flux with solar activity

International Nuclear Information System (INIS)

Lean, J.L.; Skumanich, A.

1983-01-01

A three-component model of the solar chromosphere, developed from ground based observations of the Ca II K chromospheric emission, is used to calculate the variability of the Lyman alpha flux between 1969 and 1980. The Lyman alpha flux at solar minimum is required in the model and is taken as 2.32 x 10 11 photons/cm 2 /s. This value occurred during 1975 as well as in 1976 near the commencement of solar cycle 21. The model predicts that the Lyman alpha flux increases to as much as 5 x 10 11 photons/cm 2 /s at the maximum of the solar cycle. The ratio of the average fluxes for December 1979 (cycle maximum) and July 1976 (cycle minimum) is 1.9. During solar maximum the 27-day solar rotation is shown to cause the Lyman alpha flux to vary by as much as 40% or as little as 5%. The model also shows that the Lyman alpha flux varies over intermediate time periods of 2 to 3 years, as well as over the 11-year sunspot cycle. We conclude that, unlike the sunspot number and the 10.7-cm radio flux, the Lyman alpha flux had a variability that was approximately the same during each of the past three cycles. Lyman alpha fluxes calculated by the model are consistent with measurements of the Lyman alpha flux made by 11 of a total of 14 rocket experiments conducted during the period 1969--1980. The model explains satisfactorily the absolute magnitude, long-term trends, and the cycle variability seen in the Lyman alpha irradiances by the OSO 5 satellite experiment. The 27-day variability observed by the AE-E satellite experiment is well reproduced. However, the magntidue of the AE-E 1 Lyman alpha irradiances are higher than the model calculations by between 40% and 80%. We suggest that the assumed calibration of the AE-E irradiances is in error

Lyman Alpha Control

CERN Document Server

Nielsen, Daniel Stefaniak

2015-01-01

This document gives an overview of how to operate the Lyman Alpha Control application written in LabVIEW along with things to watch out for. Overview of the LabVIEW code itself as well as the physical wiring of and connections from/to the NI PCI-6229 DAQ box is also included. The Lyman Alpha Control application is the interface between the ALPHA sequencer and the HighFinesse Wavelength Meter as well as the Lyman Alpha laser setup. The application measures the wavelength of the output light from the Lyman Alpha cavity through the Wavelength Meter. The application can use the Wavelength Meter’s PID capabilities to stabilize the Lyman Alpha laser output as well as switch between up to three frequencies.

A grand canonical genetic algorithm for the prediction of multi-component phase diagrams and testing of empirical potentials

International Nuclear Information System (INIS)

Tipton, William W; Hennig, Richard G

2013-01-01

We present an evolutionary algorithm which predicts stable atomic structures and phase diagrams by searching the energy landscape of empirical and ab initio Hamiltonians. Composition and geometrical degrees of freedom may be varied simultaneously. We show that this method utilizes information from favorable local structure at one composition to predict that at others, achieving far greater efficiency of phase diagram prediction than a method which relies on sampling compositions individually. We detail this and a number of other efficiency-improving techniques implemented in the genetic algorithm for structure prediction code that is now publicly available. We test the efficiency of the software by searching the ternary Zr–Cu–Al system using an empirical embedded-atom model potential. In addition to testing the algorithm, we also evaluate the accuracy of the potential itself. We find that the potential stabilizes several correct ternary phases, while a few of the predicted ground states are unphysical. Our results suggest that genetic algorithm searches can be used to improve the methodology of empirical potential design. (paper)

A grand canonical genetic algorithm for the prediction of multi-component phase diagrams and testing of empirical potentials.

Science.gov (United States)

Tipton, William W; Hennig, Richard G

2013-12-11

We present an evolutionary algorithm which predicts stable atomic structures and phase diagrams by searching the energy landscape of empirical and ab initio Hamiltonians. Composition and geometrical degrees of freedom may be varied simultaneously. We show that this method utilizes information from favorable local structure at one composition to predict that at others, achieving far greater efficiency of phase diagram prediction than a method which relies on sampling compositions individually. We detail this and a number of other efficiency-improving techniques implemented in the genetic algorithm for structure prediction code that is now publicly available. We test the efficiency of the software by searching the ternary Zr-Cu-Al system using an empirical embedded-atom model potential. In addition to testing the algorithm, we also evaluate the accuracy of the potential itself. We find that the potential stabilizes several correct ternary phases, while a few of the predicted ground states are unphysical. Our results suggest that genetic algorithm searches can be used to improve the methodology of empirical potential design.

Adsorption behavior of alpha -cypermethrin on cork and activated carbon.

Science.gov (United States)

Domingues, Valentina F; Priolo, Giuseppe; Alves, Arminda C; Cabral, Miguel F; Delerue-Matos, Cristina

2007-08-01

Studies were undertaken to determine the adsorption behavior of alpha -cypermethrin [R)-alpha -cyano-3-phenoxybenzyl(1S)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate, and (S)-alpha-cyano-3-phenoxybenzyl (1R)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate] in solutions on granules of cork and activated carbon (GAC). The adsorption studies were carried out using a batch equilibrium technique. A gas chromatograph with an electron capture detector (GC-ECD) was used to analyze alpha -cypermethrin after solid phase extraction with C18 disks. Physical properties including real density, pore volume, surface area and pore diameter of cork were evaluated by mercury porosimetry. Characterization of cork particles showed variations thereby indicating the highly heterogeneous structure of the material. The average surface area of cork particles was lower than that of GAC. Kinetics adsorption studies allowed the determination of the equilibrium time - 24 hours for both cork (1-2 mm and 3-4 mm) and GAC. For the studied alpha -cypermethrin concentration range, GAC revealed to be a better sorbent. However, adsorption parameters for equilibrium concentrations, obtained through the Langmuir and Freundlich models, showed that granulated cork 1-2 mm have the maximum amount of adsorbed alpha-cypermethrin (q(m)) (303 microg/g); followed by GAC (186 microg/g) and cork 3-4 mm (136 microg/g). The standard deviation (SD) values, demonstrate that Freundlich model better describes the alpha -cypermethrin adsorption phenomena on GAC, while alpha -cypermethrin adsorption on cork (1-2 mm and 3-4 mm) is better described by the Langmuir. In view of the adsorption results obtained in this study it appears that granulated cork may be a better and a cheaper alternative to GAC for removing alpha -cypermethrin from water.

Hartree-Fock and density functional theory study of alpha-cyclodextrin conformers.

Science.gov (United States)

Jiménez, Verónica; Alderete, Joel B

2008-01-31

Herein, we report the geometry optimization of four conformers of alpha-cyclodextrin (alpha-CD) by means of PM3, HF/STO-3G, HF/3-21G, HF/6-31G(d), B3LYP/6-31G(d), and X3LYP/6-31G(d) calculations. The analysis of several geometrical parameters indicates that all conformers possess bond lengths, angles, and dihedrals that agree fairly well with the crystalline structure of alpha-CD. However, only three of them (1-3) resemble the polar character of CDs and show intramolecular hydrogen-bonding patterns that agree with experimental NMR data. Among them, conformer 3 appears to be the most stable species both in the gas phase and in solution; therefore, it is expected to be the most suitable representative structure for alpha-CD conformation. The purpose of selecting such a species is to identify an appropriate structure to be employed as a starting point for reliable computational studies on complexation phenomena. Our results indicate that the choice of a particular alpha-CD conformer should affect the results of ab initio computational studies on the inclusion complexation with this cyclodextrin since both the direction and the magnitude of the dipole moment depend strongly on the conformation of alpha-CD.

Frontal alpha EEG asymmetry before and after behavioral activation treatment for depression.

Science.gov (United States)

Gollan, Jackie K; Hoxha, Denada; Chihade, Dietta; Pflieger, Mark E; Rosebrock, Laina; Cacioppo, John

2014-05-01

Mid-frontal and mid-lateral (F3/F4 and F7/F8) EEG asymmetry has been associated with motivation and affect. We examined alpha EEG asymmetry in depressed and healthy participants before and after Behavioral Activation treatment for depression; examined the association between alpha EEG asymmetry and motivational systems and affect; and evaluated the utility of alpha EEG asymmetry in predicting remission. Depressed (n=37) and healthy participants (n=35) were assessed before and after treatment using a clinical interview, a task to measure baseline EEG, and questionnaires of behavioral activation and inhibition, avoidance, and affect. Alpha EEG asymmetry was significantly higher in depressed than healthy participants at pre-treatment, positively correlated with negative affect and behavioral inhibition, and inversely correlated with lower behavioral activation sensitivity. Heightened alpha EEG asymmetry in depressed participants was significantly associated with increased behavioral inhibition and negative emotion and was independent of clinical remission. Copyright © 2014 Elsevier B.V. All rights reserved.

Quasi-linear absorption of lower hybrid waves by fusion generated alpha particles

International Nuclear Information System (INIS)

Barbato, E.; Santini, F.

1991-01-01

Lower hybrid waves are expected to be used in a steady state reactor to produce current and to control the current profile and the stability of internal modes. In the ignition phase, however, the presence of energetic alpha particles may prevent wave-electron interaction, thus reducing the current drive efficiency. This is due to the very high birth energy of the alpha particles that may absorb much of the lower hybrid wave power. This unfavourable effect is absent at high frequencies (∼ 8 GHz for typical reactor parameters). Nevertheless, because of the technical difficulties involved in using such high frequencies, it is very important to investigate whether power absorption by alpha particles would be negligible also at relatively low frequencies. Such a study has been carried out on the basis of the quasi-linear theory of wave-alpha particle interaction, since the distortion of the alpha distribution function may enhance the radiofrequency absorption above the linear level. New effects have been found, such as local alpha concentration and acceleration. The model for alpha particles is coupled with a 1-D deposition code for lower hybrid waves to calculate the competition in the power absorption between alphas and electrons as the waves propagate into the plasma core for typical reactor (ITER) parameters. It is shown that at a frequency as low as 5 GHz, power absorption by alpha particles is negligible for conventional plasma conditions and realistic alpha particle concentrations. In more ''pessimistic'' and severe conditions, negligible absorption occurs at 6 GHz. (author). 19 refs, 11 figs, 2 tabs

{alpha}-particle induced reactions on yttrium and terbium

Energy Technology Data Exchange (ETDEWEB)

Mukherjee, S.; Kumar, B.B. [School of Studies in Physics, Vikram University, Ujjain-456010 (India); Rashid, M.H. [Variable Energy Cyclotron Center, 1/AF, Bidhan Nagar, Calcutta (India); Chintalapudi, S.N. [Inter-University Consortium for DAE Facilities, 3/LB, Bidhan Nagar, Calcutta (India)

1997-05-01

The stacked foil activation technique has been employed for the investigation of {alpha}-particle induced reactions on the target elements yttrium and terbium up to 50 MeV. Six excitation functions for the ({alpha},xn) type of reactions were studied using high-resolution HPGe {gamma}-ray spectroscopy. A comparison with Blann{close_quote}s geometric dependent hybrid model has been made using the initial exciton number n{sub 0}=4(4p0h) and n{sub 0}=5(5p0h). A broad general agreement is observed between the experimental results and theoretical predictions with an initial exciton number n{sub 0}=4(4p0h). {copyright} {ital 1997} {ital The American Physical Society}

Alpha - Skew Pi - Armendariz Rings

Directory of Open Access Journals (Sweden)

Areej M Abduldaim

2018-03-01

Full Text Available In this article we introduce a new concept called Alpha-skew Pi-Armendariz rings (Alpha - S Pi - ARas a generalization of the notion of Alpha-skew Armendariz rings.Another important goal behind studying this class of rings is to employ it in order to design a modern algorithm of an identification scheme according to the evolution of using modern algebra in the applications of the field of cryptography.We investigate general properties of this concept and give examples for illustration. Furthermore, this paperstudy the relationship between this concept and some previous notions related to Alpha-skew Armendariz rings. It clearly presents that every weak Alpha-skew Armendariz ring is Alpha-skew Pi-Armendariz (Alpha-S Pi-AR. Also, thisarticle showsthat the concepts of Alpha-skew Armendariz rings and Alpha-skew Pi- Armendariz rings are equivalent in case R is 2-primal and semiprime ring.Moreover, this paper proves for a semicommutative Alpha-compatible ringR that if R[x;Alpha] is nil-Armendariz, thenR is an Alpha-S Pi-AR. In addition, if R is an Alpha - S Pi -AR, 2-primal and semiprime ring, then N(R[x;Alpha]=N(R[x;Alpha]. Finally, we look forwardthat Alpha-skew Pi-Armendariz rings (Alpha-S Pi-ARbe more effect (due to their properties in the field of cryptography than Pi-Armendariz rings, weak Armendariz rings and others.For these properties and characterizations of the introduced concept Alpha-S Pi-AR, we aspire to design a novel algorithm of an identification scheme.

Determination by transfer reaction of alpha widths in fluorine for astrophysical interest; Determination par reaction de transfert de largeurs alpha dans le fluor 19. Applications a l'astrophysique

Energy Technology Data Exchange (ETDEWEB)

Oliveira Santos, F de

1995-04-15

The nucleosynthesis of fluorine is not known. Several astrophysical models predict the alpha radiative capture onto N{sup 15} as the main fluorine production reaction. In the expression of the reaction rate, one parameter is missing: the alpha width of the resonance on the E = 4.377 MeV level in fluorine. A direct measurement is excluded due to the very low cross-section expected. We have determined this alpha width using a transfer reaction followed by analyses with FR-DWBA (Finite Range Distorted Wave Born Approximation) in a simple cluster alpha model. This experiment was carried out with a Li{sup 7} beam with E = 28 MeV onto a N{sup 15} gas target. The 16 first levels were studied. Spectroscopic factors were extracted for most of them. Alpha widths for unbound levels were determined. Many alpha width were compared with known values from direct reaction and the differences lie within the uncertainty range (factor 2). The alpha width for the E = 4.377 MeV level was determined ({gamma}{sub {alpha}} = 1.5*10{sup -15} MeV), its value is about 60 times weaker than the used value. The influence of our new rate was studied in AGB (Asymptotic Giant Branch) stars during thermal pulses. In this model the alteration is sensitive. (author)

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.

The tree-alpha Faddeev calculation on 12C bound states with a Pauli correct alpha-alpha potential

International Nuclear Information System (INIS)

Kamada, Hiroyuki; Oryu, Shinsho

1986-01-01

The three-alpha model of 12 C is investigated by the Faddeev formalism with the UIM alpha-alpha potential, in which the Pauli effect between two-alpha system was taken into account adequately. The potential can reproduce the on- and off-shell effects of the alpha-alpha interaction by the rank-4 separable type for the S-wave, the rank-3 one for the D-wave, and the rank-2 one for the G-wave, in which two of the ranks in the S-wave, and one in the D-wave are prepared to eliminate the Pauli forbidden states. We obtained three even states J π = 0 + , 2 + , 4 + , and two odd states 1 - , 3 - , below the alpha- 8 Be(0 + g.s) threshold energy. The even parity states gain larger binding energies than those which have been obtained by former Faddeev calculation with the rank-1 Kukulin and Neudatchin (KN) potential. On the other hand, for the odd parity states, we obtained smaller binding energies than the former one. It is found that our Faddeev calculation with the UIM potential does not miss any important low-lying levels of 12 C, in which any spurious states do not appear. (author)

Prediction of turbulent mixing rates of both gas and liquid phases between adjacent subchannels in a two-phase slug-churn flow

International Nuclear Information System (INIS)

Kawahara, A.; Sadatomi, M.; Tomino, T.; Sato, Y.

1998-01-01

This paper presents a slug-churn flow model for predicting turbulent mixing rates of both gas and liquid phase between adjacent subchannels in a BWR fuel rod bundle. In the model, the mixing rate of the liquid phase is calculated as the sum of the three components, i.e., turbulent diffusion, convective transfer and pressure difference fluctuations between the subchannels. The compenents of turbulent diffusion and convective transfer are calculated from Sadatomi et al.'s (1996) method, applicable to single-phase turbulent mixing by considering the effect of the increment of liquid velocity due to the presence of gas phase. The component of the pressure difference fluctuations is evaluated from a newly developed correlations. The mixing rate of the gas phase, on the other side, is calculated from a simple relation of mixing rate between gas and liquid phases. The validity of the proposed model has been confirmed with the turbulent mixing rates data of Rudzinski et al. as well as the present authors

Predicting the growth of S i3N4 nanowires by phase-equilibrium-dominated vapor-liquid-solid mechanism

Science.gov (United States)

Zhang, Yongliang; Cai, Jing; Yang, Lijun; Wu, Qiang; Wang, Xizhang; Hu, Zheng

2017-09-01

Nanomaterial synthesis is experiencing a profound evolution from empirical science ("cook-and-look") to prediction and design, which depends on the deep insight into the growth mechanism. Herein, we report a generalized prediction of the growth of S i3N4 nanowires by nitriding F e28S i72 alloy particles across different phase regions based on our finding of the phase-equilibrium-dominated vapor-liquid-solid (PED-VLS) mechanism. All the predictions about the growth of S i3N4 nanowires, and the associated evolutions of lattice parameters and geometries of the coexisting Fe -Si alloy phases, are experimentally confirmed quantitatively. This progress corroborates the general validity of the PED-VLS mechanism, which could be applied to the design and controllable synthesis of various one-dimensional nanomaterials.

Side-chain-anchored N(alpha)-Fmoc-Tyr-OPfp for bidirectional solid-phase synthesis

DEFF Research Database (Denmark)

Olsen, Christian A; Jørgensen, Malene; Hansen, Steen H

2005-01-01

[reaction: see text] A mild resin-immobilization strategy employing a readily prepared trityl bromide resin for anchoring building blocks via a phenol group has been developed. With N(alpha)-Fmoc-Tyr-OPfp as a starter building block, it was possible to prepare asymmetrically substituted hybrids...

Anomalous Temporal Behaviour of Broadband Ly Alpha Observations During Solar Flares from SDO/EVE

Science.gov (United States)

Milligan, Ryan O.; Chamberlin, Phillip C.

2016-01-01

Although it is the most prominent emission line in the solar spectrum, there has been a notable lack of studies devoted to variations in Lyman-alpha (Ly-alpha) emission during solar flares in recent years. However, the few examples that do exist have shown Ly-alpha emission to be a substantial radiator of the total energy budget of solar flares (of the order of 10 percent). It is also a known driver of fluctuations in the Earth's ionosphere. The EUV (Extreme Ultra-Violet) Variability Experiment (EVE) on board the Solar Dynamics Observatory (SDO) now provides broadband, photometric Ly-alpha data at 10-second cadence with its Multiple EUV Grating Spectrograph-Photometer (MEGS-P) component, and has observed scores of solar flares in the 5 years since it was launched. However, the MEGS-P time profiles appear to display a rise time of tens of minutes around the time of the flare onset. This is in stark contrast to the rapid, impulsive increase observed in other intrinsically chromospheric features (H-alpha, Ly-beta, LyC, C III, etc.). Furthermore, the emission detected by MEGS-P peaks around the time of the peak of thermal soft X-ray emission and not during the impulsive phase when energy deposition in the chromosphere (often assumed to be in the form of non-thermal electrons) is greatest. The time derivative of Ly-alpha lightcurves also appears to resemble that of the time derivative of soft X-rays, reminiscent of the Neupert effect. Given that spectrally-resolved Ly-alpha observations during flares from SORCE / SOLSTICE (Solar Radiation and Climate Experiment / Solar Stellar Irradiance Comparison Experiment) peak during the impulsive phase as expected, this suggests that the atypical behaviour of MEGS-P data is a manifestation of the broadband nature of the observations. This could imply that other lines andor continuum emission that becomes enhanced during flares could be contributing to the passband. Users are hereby urged to exercise caution when interpreting

Coded aperture imaging of alpha source spatial distribution

International Nuclear Information System (INIS)

Talebitaher, Alireza; Shutler, Paul M.E.; Springham, Stuart V.; Rawat, Rajdeep S.; Lee, Paul

2012-01-01

The Coded Aperture Imaging (CAI) technique has been applied with CR-39 nuclear track detectors to image alpha particle source spatial distributions. The experimental setup comprised: a 226 Ra source of alpha particles, a laser-machined CAI mask, and CR-39 detectors, arranged inside a vacuum enclosure. Three different alpha particle source shapes were synthesized by using a linear translator to move the 226 Ra source within the vacuum enclosure. The coded mask pattern used is based on a Singer Cyclic Difference Set, with 400 pixels and 57 open square holes (representing ρ = 1/7 = 14.3% open fraction). After etching of the CR-39 detectors, the area, circularity, mean optical density and positions of all candidate tracks were measured by an automated scanning system. Appropriate criteria were used to select alpha particle tracks, and a decoding algorithm applied to the (x, y) data produced the de-coded image of the source. Signal to Noise Ratio (SNR) values obtained for alpha particle CAI images were found to be substantially better than those for corresponding pinhole images, although the CAI-SNR values were below the predictions of theoretical formulae. Monte Carlo simulations of CAI and pinhole imaging were performed in order to validate the theoretical SNR formulae and also our CAI decoding algorithm. There was found to be good agreement between the theoretical formulae and SNR values obtained from simulations. Possible reasons for the lower SNR obtained for the experimental CAI study are discussed.

Synthesis of tritiated 1-alpha-methadol and 1-alpha-acetylmethadol

Energy Technology Data Exchange (ETDEWEB)

Thang, D.C.; Nam, N.H.; Pontikis, R. (Institut National de la Sante et de la Recherche Medicale (INSERM), Hopital Fernand Widal, 75 - Paris (France)); Pichat, L. (CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Service des Molecules Marquees)

1982-04-01

dl-Methadone was resolved by crystallization of its ammonium d- ..cap alpha.. -bromocamphor-..pi..-sulfonate salt to give d-methadone. The latter in ethyl acetate solution was reduced with tritium gas to 1-..cap alpha..-methadol /sup 3/H in presence of Adams platinum oxide at normal temperature and pressure. Acetylation of 1-..cap alpha..-carbinol hydrochloride by means of acetyl chloride afforded 1-..cap alpha..-acetylmethadol /sup 3/H, specific activity: 20 Ci/mMole. The positions and extent of tritium labelling were determined by /sup 3/H NMR spectroscopy.

Predictive role of HER2/neu, topoisomerase-II-alpha, and tissue inhibitor of metalloproteinases (TIMP-1) for response to adjuvant taxane-based chemotherapy in patients with intermediate-risk breast cancer: results from the WSG-AGO EC-Doc trial.

Science.gov (United States)

Erber, Ramona; Gluz, Oleg; Brünner, Nils; Kreipe, Hans Heinrich; Pelz, Enrico; Kates, Ronald; Bartels, Annette; Huober, Jens; Mohrmann, Svjetlana; Moustafa, Zehra; Liedtke, Cornelia; Möbus, Volker; Augustin, Doris; Thomssen, Christoph; Jänicke, Fritz; Kiechle, Marion; Kuhn, Walther; Nitz, Ulrike; Harbeck, Nadia; Hartmann, Arndt

2015-04-01

Taxane-anthracycline-based adjuvant chemotherapy is standard of care in patients with node-positive breast cancer (BC) but is also associated with severe side effects and significant costs. It is yet unclear, which biomarkers would predict benefit from taxanes and/or general chemoresistance. In this study, we investigate a large cohort of patients with intermediate-risk BC treated within the WSG EC-DOC Trial for the predictive impact of topoisomerase-II-alpha, HER2/neu, and TIMP-1. Tumor tissue was available in a representative cohort of 772 cases of the WSG EC-DOC Trial collective which compared 4xEC-4xDoc versus 6xCEF/CMF. In addition to hormone receptor status and Ki-67, HER2/neu+ and topoisomerase-II-alpha status using fluorescence in situ hybridisation (FISH) and immunohistochemistry, TIMP-1 using immunohistochemistry, and aneuploidy of chromosome 17 using FISH were evaluated and correlated with outcome and taxane benefit. There was significant superiority of EC-Doc over CEF regarding 5-year DFS (90 vs. 80 %, respectively, p = 0.006) particularly in patient subgroups defined by HR+, HER2/neu+, high proliferation (i.e., Ki-67 ≥ 20 %), patient age >50 years old and normal chromosome 17 status, high TIMP-1 and low topoisomerase-II-alpha protein expression. Significant prognostic factors in multivariate analysis were EC-Doc therapy (HR = 0.61; 95 %CI 0.38-0.986), age Doc vs. CEF) and high topoisomerase-II-alpha protein expression (HR = 0.427; 95 %CI 0.203-0.900) in multivariate interaction analysis. Despite of univariate predictive effect of HER2/neu status among other factors only topoisomerase-II-alpha protein expression was associated with significant benefit from EC-Doc compared to CEF by multivariate interaction analysis.

Water transport by the bacterial channel alpha-hemolysin

Science.gov (United States)

Paula, S.; Akeson, M.; Deamer, D.

1999-01-01

This study is an investigation of the ability of the bacterial channel alpha-hemolysin to facilitate water permeation across biological membranes. alpha-Hemolysin channels were incorporated into rabbit erythrocyte ghosts at varying concentrations, and water permeation was induced by mixing the ghosts with hypertonic sucrose solutions. The resulting volume decrease of the ghosts was followed by time-resolved optical absorption at pH 5, 6, and 7. The average single-channel permeability coefficient of alpha-hemolysin for water ranged between 1.3x10-12 cm/s and 1.5x10-12 cm/s, depending on pH. The slightly increased single-channel permeability coefficient at lower pH-values was attributed to an increase in the effective pore size. The activation energy of water transport through the channel was low (Ea=5.4 kcal/mol), suggesting that the properties of water inside the alpha-hemolysin channel resemble those of bulk water. This conclusion was supported by calculations based on macroscopic hydrodynamic laws of laminar water flow. Using the known three-dimensional structure of the channel, the calculations accurately predicted the rate of water flow through the channel. The latter finding also indicated that water permeation data can provide a good estimate of the pore size for large channels.

Low-pH-induced transformation of bilayer membrane into bicontinuous cubic phase in dioleoylphosphatidylserine/monoolein membranes.

Science.gov (United States)

Okamoto, Yoshihide; Masum, Shah Md; Miyazawa, Haruna; Yamazaki, Masahito

2008-04-01

Cubic biomembranes, nonbilayer membranes with connections in three-dimensional space that have a cubic symmetry, have been observed in various cells. Interconversion between the bilayer liquid-crystalline (L(alpha)) phase and cubic phases attracted much attention in terms of both biological and physicochemical aspects. Herein we report the pH effect on the phase and structure of dioleoylphosphatidylserine (DOPS)/monoolein (MO) membranes under a physiological ion concentration condition, which was revealed by small-angle X-ray scattering (SAXS) measurement. At neutral pH, DOPS/MO membranes containing high concentrations of DOPS were in the L(alpha) phase. First, the pH effect on the phase and structure of the multilamellar vesicles (MLVs) of the DOPS/MO membranes preformed at neutral pH was investigated by adding various low-pH buffers into the MLV suspension. For 20%-DOPS/80%-MO MLVs, at and below pH 2.9, a transition from the L(alpha) to cubic (Q(224)) phase occurred within 1 h. This phase transition was reversible; a subsequent increase in pH to a neutral one in the membrane suspension transformed the cubic phase into the original L(alpha) phase. Second, we found that a decrease in pH transformed large unilamellar vesicles of DOPS/MO membranes into the cubic phase under similar conditions. We have proposed the mechanism of the low-pH-induced phase transition and also made a quantitative analysis on the critical pH of the phase transition. This finding is the first demonstration that a change in pH can induce a reversible phase transition between the L(alpha) and cubic phases of lipid membranes within 1 h.

Enthalpies of combustion and formation of {alpha}-D-glucoheptono-1,4-lactone and {alpha},{beta}-glucooctanoic-1,4-lactone

Energy Technology Data Exchange (ETDEWEB)

Amador, Patricia [Facultad de Ciencias Qui' micas, Benemerita Universidad Autonoma de Puebla, 14 Sur y Av. San Claudio, Col. Manuel, C.P. 72570 Puebla Pue (Mexico)], E-mail: cs000721@siu.buap.mx; Mata, Marian Y.; Flores, Henoc [Facultad de Ciencias Qui' micas, Benemerita Universidad Autonoma de Puebla, 14 Sur y Av. San Claudio, Col. Manuel, C.P. 72570 Puebla Pue (Mexico)

2008-05-15

The standard molar energies of combustion, {delta}{sub c}U{sub m}{sup 0}(cr,298.15K), of {alpha}-D-glucoheptono-1,4-lactone (GH) and {alpha},{beta}-glucooctanoic-1,4-lactone (GO) were obtained by micro-combustion calorimetry. The obtained values are -(2924.6 {+-} 2.3) kJ . mol{sup -1} and -(3459.5 {+-} 2.5) kJ . mol{sup -1}, respectively. From combustion energies, the standard molar enthalpies of formation in crystalline phase, {delta}{sub f}H{sub m}{sup 0}(cr,298.15K), for GH and GO were determined as -(1546.2 {+-} 2.5) kJ . mol{sup -1} and -(1690.6 {+-} 2.7) kJ . mol{sup -1}, respectively. Also it was found that when the hydroxyl group number increases in the aldonolactones their standard molar enthalpies of formation increase too.

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.

Alpha self-irradiation effects in ternary oxides of actinides elements: The zircon-like phases AmIIIVO4 and AIINpIV(VO4)2 (A=Sr, Pb)

International Nuclear Information System (INIS)

Goubard, F.; Griesmar, P.; Tabuteau, A.

2005-01-01

We report the experimental studies of irradiation damage from alpha decay in neptunium and americium vanadates versus cumulative dose. The isotopes used were the transuranium α-emitter 237 Np and the α,γ-emitter 241 Am. Neptunium and americium vanadates self-irradiation was studied by X-ray diffraction method (XRD). The comparison of the powder diffraction patterns reveal that the irradiation has no apparent effect on the neptunium phases while the americium vanadate swells and becomes metamict as a function of cumulative dose

Determination by transfer reaction of alpha widths in fluorine for astrophysical interest

International Nuclear Information System (INIS)

Oliveira Santos, F. de

1995-04-01

The nucleosynthesis of fluorine is not known. Several astrophysical models predict the alpha radiative capture onto N 15 as the main fluorine production reaction. In the expression of the reaction rate, one parameter is missing: the alpha width of the resonance on the E = 4.377 MeV level in fluorine. A direct measurement is excluded due to the very low cross-section expected. We have determined this alpha width using a transfer reaction followed by analyses with FR-DWBA (Finite Range Distorted Wave Born Approximation) in a simple cluster alpha model. This experiment was carried out with a Li 7 beam with E = 28 MeV onto a N 15 gas target. The 16 first levels were studied. Spectroscopic factors were extracted for most of them. Alpha widths for unbound levels were determined. Many alpha width were compared with known values from direct reaction and the differences lie within the uncertainty range (factor 2). The alpha width for the E = 4.377 MeV level was determined (Γ α = 1.5*10 -15 MeV), its value is about 60 times weaker than the used value. The influence of our new rate was studied in AGB (Asymptotic Giant Branch) stars during thermal pulses. In this model the alteration is sensitive. (author)

Ramsdellite-structured LiTiO 2: A new phase predicted from ab initio calculations

Science.gov (United States)

Koudriachova, M. V.

2008-06-01

A new phase of highly lithiated titania with potential application as an anode in Li-rechargeable batteries is predicted on the basis of ab initio calculations. This phase has a composition LiTiO2 and may be accessed through electrochemical lithiation of ramsdellite-structured TiO2 at the lowest potential reported for titanium dioxide based materials. The potential remains constant over a wide range of Li-concentrations. The new phase is metastable with respect to a tetragonally distorted rock salt structure, which hitherto has been the only known polymorph of LiTiO2.

Determination by transfer reaction of alpha widths in fluorine for astrophysical interest; Determination par reaction de transfert de largeurs alpha dans le fluor 19. Applications a l'astrophysique

Energy Technology Data Exchange (ETDEWEB)

Oliveira Santos, F. de

1995-04-15

The nucleosynthesis of fluorine is not known. Several astrophysical models predict the alpha radiative capture onto N{sup 15} as the main fluorine production reaction. In the expression of the reaction rate, one parameter is missing: the alpha width of the resonance on the E = 4.377 MeV level in fluorine. A direct measurement is excluded due to the very low cross-section expected. We have determined this alpha width using a transfer reaction followed by analyses with FR-DWBA (Finite Range Distorted Wave Born Approximation) in a simple cluster alpha model. This experiment was carried out with a Li{sup 7} beam with E = 28 MeV onto a N{sup 15} gas target. The 16 first levels were studied. Spectroscopic factors were extracted for most of them. Alpha widths for unbound levels were determined. Many alpha width were compared with known values from direct reaction and the differences lie within the uncertainty range (factor 2). The alpha width for the E = 4.377 MeV level was determined ({gamma}{sub {alpha}} = 1.5*10{sup -15} MeV), its value is about 60 times weaker than the used value. The influence of our new rate was studied in AGB (Asymptotic Giant Branch) stars during thermal pulses. In this model the alteration is sensitive. (author)

The Paramagnetism of Dissolved Mn in {alpha} and {beta} Brasses

Energy Technology Data Exchange (ETDEWEB)

Myers, H P; Westin, R

1962-12-15

Paramagnetic susceptibility measurements have been made on {alpha} and {beta} brasses containing {approx} 1 w/o Mn. The susceptibility varied with temperature according to the Curie Weiss law and the Curie constant and thereby the Bohr magneton number per Mn atom were determined. Interpreted in terms of valency, Mn monovalent in copper has a valency in {alpha} brass which decreases progressively with zinc content attaining the value 0.58 at the limiting of composition. Mn in {beta} brass exhibits a valency 0.8. These results are not in keeping with previous values for the valency of manganese as determined from phase boundary relationships and electron to atom ratios.

[Voluntary alpha-power increasing training impact on the heart rate variability].

Science.gov (United States)

Bazanova, O M; Balioz, N V; Muravleva, K B; Skoraia, M V

2013-01-01

biofeedback training has no such effect. The positive correlation between the alpha-peak frequency and pNN50 in patients with initially low, but negative--those with high baseline alpha frequency explains the multidirectional biofeedback effects on HRV in low and high alpha frequency subjects. The individual alpha-frequency EEG pattern determines the effectiveness of the alpha EEG biofeedback training in changing heart rate variability, which provides a basis for predicting the results and develop individual approaches to the biofeedback technology implementation that can be used in clinical practice for treatment and rehabilitation of psychosomatic syndromes and in educational training.

Mindfulness starts with the body: Somatosensory attention and top-down modulation of cortical alpha rhythms in mindfulness meditation

Directory of Open Access Journals (Sweden)

Catherine E Kerr

2013-02-01

Full Text Available Mindfulness Based Stress Reduction (MBSR and Mindfulness Based Cognitive Therapy (MBCT use a common set of exercises to reduce distress in chronic pain and decrease risk of depression relapse. These standardized mindfulness (ST-Mindfulness practices predominantly require attending to breath and body sensations. Here, we offer a novel view of ST-Mindfulness’s somatic focus as a form of training for optimizing attentional modulation of 7-14 Hz alpha rhythms that play a key role in filtering inputs to primary sensory neocortex and organizing the flow of sensory information. In support of the framework, we describe our previous finding (Kerr et al, 2011 that ST-Mindfulness enhanced attentional regulation of alpha in primary somatosensory cortex (SI. The framework allows us to make several predictions. In chronic pain, we predict somatic attention in ST-Mindfulness de-biases alpha in SI, freeing up pain-focused attentional resources. In depression relapse, we predict ST-Mindfulness’s somatic attention competes with internally focused rumination, as internally focused cognitive processes (e.g., working and short term memory rely on alpha filtering of sensory input. Our computational model (Jones et al, 2009 predicts ST-Mindfulness enhances top-down modulation of alpha by facilitating precise alterations in timing and efficacy of SI thalamocortical inputs. We conclude by considering how the proposed framework aligns with Buddhist teachings that mindfulness starts with mindfulness of the body. Translating this theory into neurophysiology, we hypothesize that with its somatic focus, mindfulness’ top-down alpha rhythm modulation in SI enhances gain control which, in turn, sensitizes practitioners to better detect and regulate when the mind wanders from its somatic focus. This enhanced regulation of somatic mind-wandering may be an early stage of mindfulness training, leading to cognitive regulation and metacognition.

Hippocampal 3alpha,5alpha-THP may alter depressive behavior of pregnant and lactating rats.

Science.gov (United States)

Frye, Cheryl A; Walf, Alicia A

2004-07-01

The 5alpha-reduced metabolite of progesterone (P), 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP), may mediate progestins' effects to reduce depressive behavior of female rats in part through actions in the hippocampus. To investigate, forced swim test behavior and plasma and hippocampal progestin levels were assessed in groups of rats expected to differ in their 3alpha,5alpha-THP levels due to endogenous differences (pregnant and postpartum), administration of a 5alpha-reductase inhibitor (finasteride; 50 mg/kg sc), and/or gestational stress [prenatal stress (PNS)], an animal model of depression. Pregnant rats had higher plasma and hippocampal 3alpha,5alpha-THP levels and less depressive behavior (decreased immobility, increased struggling and swimming) in the forced swim test than did postpartum rats. Finasteride, compared to vehicle-administration, reduced plasma and hippocampal 3alpha,5alpha-THP levels and increased depressive behavior (increased immobility, decreased struggling and swimming). PNS was associated with lower hippocampal, but not plasma, 3alpha,5alpha-THP levels and increased swimming compared to that observed in control rats. Together, these data suggest that 3alpha,5alpha-THP in the hippocampus may mediate antidepressive behavior of female rats.

A fragment of alpha-actinin promotes monocyte/macrophage maturation in vitro.

Science.gov (United States)

Luikart, S; Wahl, D; Hinkel, T; Masri, M; Oegema, T

1999-02-01

Conditioned media (CM) from cultures of HL-60 myeloid leukemia cells grown on extracellular bone marrow matrix contains a factor that induces macrophage-like maturation of HL-60 cells. This factor was purified from the CM of HL-60 cells grown on bone marrow stroma by ammonium sulfate precipitation, then sequential chromatography on DEAE, affi-gel blue affinity, gel exclusion, and wheat germ affinity columns, followed by C-4 reverse phase HPLC, and SDS-PAGE. The maturation promoting activity of the CM was identified in a single 31 kD protein. Amino acid sequence analysis of four internal tryptic peptides of this protein confirmed significant homology with amino acid residues 48-60, 138-147, 215-220, and 221-236 of human cytoskeletal alpha-actinin. An immunoaffinity purified rabbit polyclonal anti-chicken alpha-actinin inhibited the activity of HL-60 conditioned media. A 27 kD amino-terminal fragment of alpha-actinin produced by thermolysin digestion of chicken gizzard alpha-actinin, but not intact alpha-actinin, had maturation promoting activity on several cell types, including blood monocytes, as measured by lysozyme secretion and tartrate-resistant acid phosphatase staining. We conclude that an extracellular alpha-actinin fragment can promote monocyte/macrophage maturation. This represents the first example of a fragment of a cytoskeletal component, which may be released during tissue remodeling and repair, playing a role in phagocyte maturation.

Formation of omega phase under shock pressure, hydrostatic pressure and irradiation

International Nuclear Information System (INIS)

Dey, G.K.

2016-01-01

The omega transformation is one of the most intriguing phase transformations. The aspects which make it unique and interesting are the facts that this phase can form from two different parent phases viz. the alpha phase and the beta phase. The alpha to omega transformation has been observed under shock and static pressure and the mechanism involved has been studied in detail. Starting from the nucleation stage to the completion of the transformation, various interesting aspects of the mechanism of transformation has emerged in these studies. Although the parent and product phases are same under these conditions of transformation, a variation in the morphology and the kinetics of the product phase indicate different pathways for alpha to omega transformations. Similarly, the beta to omega transformation is also replete with several interesting features. This transformation can occur under application of pressure, thermal activation and also under irradiation. Here again the morphology of the product phase, the nucleation mechanisms and the kinetics of the phase transformation depend on the path of transformation, though the parent and product phases are same in each path. This presentation highlights the formation of the omega phase under different activations including the ones in extreme conditions in pure Zr and Zr based alloys. Theoretical aspects of the feasibility, pathways and kinetics of the transformations are also emphasized. (author)

Properties predictive modeling through the concept of a hybrid interphase existing between phases in contact

Science.gov (United States)

Portan, D. V.; Papanicolaou, G. C.

2018-02-01

From practical point of view, predictive modeling based on the physics of composite material behavior is wealth generating; by guiding material system selection and process choices, by cutting down on experimentation and associated costs; and by speeding up the time frame from the research stage to the market place. The presence of areas with different properties and the existence of an interphase between them have a pronounced influence on the behavior of a composite system. The Viscoelastic Hybrid Interphase Model (VHIM), considers the existence of a non-homogeneous viscoelastic and anisotropic interphase having properties depended on the degree of adhesion between the two phases in contact. The model applies for any physical/mechanical property (e.g. mechanical, thermal, electrical and/or biomechanical). Knowing the interphasial variation of a specific property one can predict the corresponding macroscopic behavior of the composite. Moreover, the model acts as an algorithm and a two-way approach can be used: (i) phases in contact may be chosen to get the desired properties of the final composite system or (ii) the initial phases in contact determine the final behavior of the composite system, that can be approximately predicted. The VHIM has been proven, amongst others, to be extremely useful in biomaterial designing for improved contact with human tissues.

Two approaches in preparation for cogeneration alpha-tocopherol and biodiesel from cottonseed

Energy Technology Data Exchange (ETDEWEB)

Zhu, Q.-L.; Zang, L.-Y.; Zhang, L.; Yun, Z. [Nanjing University of Technology (China)

2012-02-15

Vitamin E is a group of lipid soluble antioxidants that is widely used in the food, cosmetic and medical industries. It is comprised of four tocopherols and four tocotrienols, i.e. alpha, beta, gamma and delta, which are characterized by a chromanol ring structure with a distinct substitution pattern of methyl groups. This paper presents two approaches in preparation for co-generation of alpha-tocopherol and biodiesel from cottonseed. The approaches are a two-step process and a direct alkaline trans-esterification process. Using single factor experiments and an orthogonal design method, the effects of certain factors on the alpha-tocopherol recovery and conversion of cottonseed oil to biodiesel in both processes was systematically studied. In the two-step process, biodiesel and alpha-tocopherol were produced using a two-phase solvent combined with base-catalyzed trans-esterification. It was observed that 95.5% cottonseed oil was converted to biodiesel. In the direct-alkaline trans-esterification process, 98.3% cottonseed oil was converted to biodiesel.

Determination of uranium and thorium isotopes by solid phase extraction and alpha spectrometry

International Nuclear Information System (INIS)

Kuruc, J.; Kovacova, M.; Strisovska, J.; Galanda, D.

2013-01-01

The aim of this work was to test the modified method suitable for the separation of isotopes of uranium and thorium samples of rocks, including gold ore and gold concentrate using of extraction chromatography method, after digestion of the sample, concentrating, separate the isotopes of uranium and thorium isotopes to prepare sources for the measurement of alpha spectra. Samples of rocks, gold ore and gold concentrate were digered in microwave decomposition in the environment of hydrogen peroxide and concentrated nitric acid. For the separation of uranium and thorium the vacuum box with cartridges DGA Resin and Resin(R) UTEVA (Triskem International, France) was used. Both sorbents allow separation of uranium from thorium. The results confirmed that the both sorbents give the same results within expanded uncertainty. The mass activity of monitored uranium and thorium radioisotopes was determined by alpha spectrometry method. The yields of separation were determined using uranium-232 as a tracer radionuclide; the activity of 232 U was 0.1438 Bq. Alpha spectra were measured on the Alpha spectrometer EG and G ORTEC 576A with the software MAESTRO, MCA Emulator and Gamma Vision-32 for Windows, USA. Mass activities of radionuclides were converted to mass concentration of isotopes 238 U, 234 U, 232 Th, 230 Th and 228 Th. The highest concentration of 238 U was sampled in granodiorite (Tunnel S-XIV-2, southwards, mining of Cu ore, not working there since 1990), where m( 238 U) = (0.81 ± 0.09) mg kg -1 (DGA Resin) and m( 238 U) = (0.90 ± 0.09) mg kg -1 (UTEVA(R) Resin), as well as m( 232 Th) = (18.8 ± 1.7) mg kg -1 (DGA Resin) and m( 232 Th) = (17.8 ± 1.5) mg kg -1 (UTEVA(R) Resin). In other samples of rocks, gold ore and gold concentrates have specific masses of isotopes of uranium and thorium two-to ten-folds lower. It can be concluded that the rocks, gold ores and concentrates of gold from the 'Rozalia' mine contain lower concentrations of uranium several times against

Evidence for a prolonged role of alpha 4 integrin throughout active experimental allergic encephalomyelitis.

Science.gov (United States)

Keszthelyi, E; Karlik, S; Hyduk, S; Rice, G P; Gordon, G; Yednock, T; Horner, H

1996-10-01

The leukocyte integrin receptor, alpha 4 beta 1, and its endothelial cell ligand, vascular cell adhesion molecule 1, appear to be of critical importance in the leukocyte trafficking that accompanies CNS damage in experimental allergic encephalomyelitis (EAE). In this study, the persistence of the role for alpha 4 beta 1/VCAM-1 in EAE was established by observing antibody-mediated disease reversal up to 1 month following disease onset. Limited treatment with a monoclonal antibody against alpha 4 integrin, GG5/3, resulted in a significant decrease in both clinical and histopathologic signs. This was not observed in isotype control experiments. In the latter phase of progressive disease, widespread demyelination occurred in the animals that did not respond to 6 days of anti-alpha 4 treatment. These results demonstrate an essential role for alpha 4 beta 1 interactions throughout active EAE and illustrate the difference between reversible clinical deficits caused by edema and irreversible deficits associated with demyelination.

A simple source preparation method for alpha-ray spectrometry of volcanic rock sample

International Nuclear Information System (INIS)

Takahashi, Masaomi; Kurihara, Yuichi; Sato, Jun

2006-01-01

A simple source preparation method was developed for the alpha-ray spectrometry to determine U and Th in volcanic rockes. Isolation of U and Th from volcanic rocks was made by use of UTEVA-Spec. resin, extraction chromatograph material. U and Th were extracted by TTA-benzene solution and organic phase was evaporated drop by drop on a hot stainless steel planchet to dryness. This method was found to be effective for the preparation of sources for alpha-ray spectrometry. (author)

Path Dependency of High Pressure Phase Transformations

Science.gov (United States)

Cerreta, Ellen

2017-06-01

At high pressures titanium and zirconium are known to undergo a phase transformation from the hexagonal close packed (HCP), alpha-phase to the simple-hexagonal, omega-phase. Under conditions of shock loading, the high-pressure omega-phase can be retained upon release. It has been shown that temperature, peak shock stress, and texture can influence the transformation. Moreover, under these same loading conditions, plastic processes of slip and twinning are also affected by similar differences in the loading path. To understand this path dependency, in-situ velocimetry measurements along with post-mortem metallographic and neutron diffraction characterization of soft recovered specimens have been utilized to qualitatively understand the kinetics of transformation, quantify volume fraction of retained omega-phase and characterize the shocked alpha and omega-phases. Together the work described here can be utilized to map the non-equilibrium phase diagram for these metals and lend insight into the partitioning of plastic processes between phases during high pressure transformation. In collaboration with: Frank Addesssio, Curt Bronkhorst, Donald Brown, David Jones, Turab Lookman, Benjamin Morrow, Carl Trujillo, Los Alamos National Lab.; Juan Pablo Escobedo-Diaz, University of New South Wales; Paulo Rigg, Washington State University.

The heavy quarkonium spectrum at order $m\\alpha_{s}^{5}\\ln\\alpha_{s}$

CERN Document Server

Brambilla, Nora; Soto, Joan; Vairo, Antonio

1999-01-01

We compute the complete leading-log terms of the next-to-next-to-next-to-leading-order corrections to potential NRQCD. As a by-product we obtain the leading logs at $O(m\\alpha_s^5)$ in the heavy quarkonium spectrum. These leading logs, when $\\Lambda_{QCD} \\ll m\\alpha_s^2$, give the complete $O(m\\alpha_s^5 \\ln \\alpha_s)$ corrections to the heavy quarkonium spectrum.

Vapour pressure of components made by the presence of HgS(s,alpha) in an oil/gas reservoir and consequences for the produced gas

Energy Technology Data Exchange (ETDEWEB)

Oestvold, T.; Gustavsen, Oe.; Grande, K.; Aas, N.; Olsvik, Mimmi Kjetsaa

2006-03-15

A thermodynamic analysis is presented on how components made from HgS (s,alpha), existing in a oil/gas reservoir, will distribute themselves between gas, water, liquid and solid components as a function of temperature and pressure. The consequence of the formation of mercury containing components on gas injection and on gas quality is discussed. Since equilibrium is established in the model calculation, other gas components in the gas phase and components in condensed phases present will also influence the composition of the gas. Six cases are considered in the calculation: 1) HgS(s,alpha) - Ar(g), 2) HgS(s,alpha) - Ar (g) - water with 10-4 molal NaCl at pH = 7, 3) HgS(s,alpha) - CH{sub 4}(g), 4) HgS(s,alpha) - CH{sub 4} (g) - water with 10-4 molal NaCl at pH = 7 and 5) HgS(s,alpha) - natural gas - water with 10-4 molal NaCl at pH = 7, 6) HgS(s,alpha) - natural gas - water with 10-4 molal NaCl and 5*10-5 molal NO-3- at pH = 7. When HgS(s,alpha) is present in an oil reservoir at 170 deg C and 200 bar, these calculations show that the major components formed are: H{sub 2}(g), H{sub 2}S(g), Hg(l) and Hg(g) together with carbon. Mercury in the gas phase in the cases 1) is 4*10-7 bar and is determined by the evaporation and decomposition HgS(g) in the reservoir. In case 2) P{sub Hg} = 5.7*10-4 bar mainly determined by the formation of sulphate in the water phase. In the cases 3), 4) and 5) these calculations show that the major components formed are: H{sub 2}(g), H{sub 2}S(g), Hg(l) and Hg(g) together with carbon, and the gas phase is dominated by Hg(g) at approx. *10-3 bar. The water phase may contain Hg(CH{sub 3}NH{sub 2}){sub 2}2+ if NO{sub 3}- for some reasons is introduced into the formation water, and the very carcinogenic dimethyl mercury compound, C{sub 2}HgH{sub 6}, can be formed in the gas phase. Both compounds, however, in insignificant low concentration/partial pressure. (Author)

1 H MR spectroscopy in cervical carcinoma using external phase array body coil at 3.0 Tesla: Prediction of poor prognostic human papillomavirus genotypes.

Science.gov (United States)

Lin, Gigin; Lai, Chyong-Huey; Tsai, Shang-Yueh; Lin, Yu-Chun; Huang, Yu-Ting; Wu, Ren-Chin; Yang, Lan-Yan; Lu, Hsin-Ying; Chao, Angel; Wang, Chiun-Chieh; Ng, Koon-Kwan; Ng, Shu-Hang; Chou, Hung-Hsueh; Yen, Tzu-Chen; Hung, Ji-Hong

2017-03-01

To assess the clinical value of proton ( 1 H) MR spectroscopy in cervical carcinomas, in the prediction of poor prognostic human papillomavirus (HPV) genotypes as well as persistent disease following concurrent chemoradiotherapy (CCRT). 1 H MR spectroscopy using external phase array coil was performed in 52 consecutive cervical cancer patients at 3 Tesla (T). Poor prognostic HPV genotypes (alpha-7 species or absence of HPV infection) and persistent cervical carcinoma after CCRT were recorded. Statistical significance was calculated with the Mann-Whitney two-sided nonparametric test and areas under the receiver operating characteristics curve (AUC) analysis. A 4.3-fold (P = 0.032) increased level of methyl resonance at 0.9 ppm was found in the poor prognostic HPV genotypes, mainly attributed to the presence of HPV18, with a sensitivity of 75%, a specificity of 81%, and an AUC of 0.76. Poor prognostic HPV genotypes were more frequently observed in patients with adeno-/adenosquamous carcinoma (Chi-square, P < 0.0001). In prediction of the four patients with persistent disease after CCRT, elevated methyl resonance demonstrated a sensitivity of 100%, a specificity of 74%, and an AUC of 0.82. 1 H MR spectroscopy at 3T can be used to depict the elevated lipid resonance levels in cervical carcinomas, as well as help to predict the poor prognostic HPV genotypes and persistent disease following CCRT. Further large studies with longer follow up times are warranted to validate our initial findings. 1 J. Magn. Reson. Imaging 2017;45:899-907. © 2016 International Society for Magnetic Resonance in Medicine.

ERPs and oscillations during encoding predict retrieval of digit memory in superior mnemonists.

Science.gov (United States)

Pan, Yafeng; Li, Xianchun; Chen, Xi; Ku, Yixuan; Dong, Yujie; Dou, Zheng; He, Lin; Hu, Yi; Li, Weidong; Zhou, Xiaolin

2017-10-01

Previous studies have consistently demonstrated that superior mnemonists (SMs) outperform normal individuals in domain-specific memory tasks. However, the neural correlates of memory-related processes remain unclear. In the current EEG study, SMs and control participants performed a digit memory task during which their brain activity was recorded. Chinese SMs used a digit-image mnemonic for encoding digits, in which they associated 2-digit groups with images immediately after the presentation of each even-position digit in sequences. Behaviorally, SMs' memory of digit sequences was better than the controls'. During encoding in the study phase, SMs showed an increased right central P2 (150-250ms post onset) and a larger right posterior high-alpha (10-14Hz, 500-1720ms) oscillation on digits at even-positions compared with digits at odd-positions. Both P2 and high-alpha oscillations in the study phase co-varied with performance in the recall phase, but only in SMs, indicating that neural dynamics during encoding could predict successful retrieval of digit memory in SMs. Our findings suggest that representation of a digit sequence in SMs using mnemonics may recruit both the early-stage attention allocation process and the sustained information preservation process. This study provides evidence for the role of dynamic and efficient neural encoding processes in mnemonists. Copyright © 2017. Published by Elsevier Inc.

Diagnostical meaning acute phase proteins in cerebrospinal liquid in children with neuroinfections

Directory of Open Access Journals (Sweden)

L. A. Alekseeva

2010-01-01

Full Text Available In the article presented results of the examination of acute phase proteins in cerebrospinal liquid in 237 children with meningitis and encephalitis viral and bacterial etiology. The dependence between the level of acute phase proteins in cerebrospinal liquid and etiology of neuroinfectional process, the severity of brain damage and the process stage was determined. Diagnostic and prognostic efficiency of the acute phase proteins (C-reactive protein, albumin, alpha-1-antitripsin, alpha-2-macroglobulin, gaptoglobin examination in children with neuroinfections was specified. Developed method of express diagnostics of the severity of inflammatory damage of the brain in bacterial meningitis in children by determination in cerebrospinal liquid alpha-2-macroglobulin is described.

Predictive role of HER2/neu, topoisomerase-II-alpha, and tissue inhibitor of metalloproteinases (TIMP-1) for response to adjuvant taxane-based chemotherapy in patients with intermediate-risk breast cancer

DEFF Research Database (Denmark)

Erber, Ramona; Gluz, Oleg; Brünner, Nils

2015-01-01

. In this study, we investigate a large cohort of patients with intermediate-risk BC treated within the WSG EC-DOC Trial for the predictive impact of topoisomerase-II-alpha, HER2/neu, and TIMP-1. Tumor tissue was available in a representative cohort of 772 cases of the WSG EC-DOC Trial collective which compared 4...

How to find soluble proteins: a comprehensive analysis of alpha/beta hydrolases for recombinant expression in E. coli

Directory of Open Access Journals (Sweden)

Barth Sandra

2005-04-01

Full Text Available Abstract Background In screening of libraries derived by expression cloning, expression of active proteins in E. coli can be limited by formation of inclusion bodies. In these cases it would be desirable to enrich gene libraries for coding sequences with soluble gene products in E. coli and thus to improve the efficiency of screening. Previously Wilkinson and Harrison showed that solubility can be predicted from amino acid composition (Biotechnology 1991, 9(5:443–448. We have applied this analysis to members of the alpha/beta hydrolase fold family to predict their solubility in E. coli. alpha/beta hydrolases are a highly diverse family with more than 1800 proteins which have been grouped into homologous families and superfamilies. Results The predicted solubility in E. coli depends on hydrolase size, phylogenetic origin of the host organism, the homologous family and the superfamily, to which the hydrolase belongs. In general small hydrolases are predicted to be more soluble than large hydrolases, and eukaryotic hydrolases are predicted to be less soluble in E. coli than prokaryotic ones. However, combining phylogenetic origin and size leads to more complex conclusions. Hydrolases from prokaryotic, fungal and metazoan origin are predicted to be most soluble if they are of small, medium and large size, respectively. We observed large variations of predicted solubility between hydrolases from different homologous families and from different taxa. Conclusion A comprehensive analysis of all alpha/beta hydrolase sequences allows more efficient screenings for new soluble alpha/beta hydrolases by the use of libraries which contain more soluble gene products. Screening of hydrolases from families whose members are hard to express as soluble proteins in E. coli should first be done in coding sequences of organisms from phylogenetic groups with the highest average of predicted solubility for proteins of this family. The tools developed here can be used

Diagnostical meaning acute phase proteins in cerebrospinal liquid in children with neuroinfections

OpenAIRE

L. A. Alekseeva; N. V. Skripchenko; T. V. Bessonova

2010-01-01

In the article presented results of the examination of acute phase proteins in cerebrospinal liquid in 237 children with meningitis and encephalitis viral and bacterial etiology. The dependence between the level of acute phase proteins in cerebrospinal liquid and etiology of neuroinfectional process, the severity of brain damage and the process stage was determined. Diagnostic and prognostic efficiency of the acute phase proteins (C-reactive protein, albumin, alpha-1-antitripsin, alpha-2-macr...

Energy dependence of event shapes and of $\\alpha_s$ at LEP 2

CERN Document Server

Abreu, P; Adye, T; Adzic, P; Albrecht, Z; Alderweireld, T; Alekseev, G D; Alemany, R; Allmendinger, T; Allport, P P; Almehed, S; Amaldi, Ugo; Amapane, N; Amato, S; Anassontzis, E G; Andersson, P; Andreazza, A; Andringa, S; Antilogus, P; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barbiellini, Guido; Barbier, R; Bardin, Dimitri Yuri; Barker, G; Baroncelli, A; Battaglia, Marco; Baubillier, M; Becks, K H; Begalli, M; Behrmann, A; Beillière, P; Belokopytov, Yu A; Belous, K S; Benekos, N C; Benvenuti, Alberto C; Bérat, C; Berggren, M; Bertini, D; Bertrand, D; Besançon, M; Bianchi, F; Bigi, M; Bilenky, S M; Bizouard, M A; Bloch, D; Blom, H M; Bonesini, M; Bonivento, W; Boonekamp, M; Booth, P S L; Borgland, A W; Borisov, G; Bosio, C; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Boyko, I; Bozovic, I; Bozzo, M; Branchini, P; Brenke, T; Brenner, R A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschbeck, Brigitte; Buschmann, P; Cabrera, S; Caccia, M; Calvi, M; Camporesi, T; Canale, V; Carena, F; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Chabaud, V; Chapkin, M M; Charpentier, P; Chaussard, L; Checchia, P; Chelkov, G A; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Chudoba, J; Cieslik, K; Collins, P; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Cowell, J H; Crawley, H B; Crennell, D J; Crépé, S; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Davenport, Martyn; Da Silva, W; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Clercq, C; De Lotto, B; De Min, A; De Paula, L S; Dijkstra, H; Di Ciaccio, Lucia; Dolbeau, J; Doroba, K; Dracos, M; Drees, J; Dris, M; Duperrin, A; Durand, J D; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Ellert, M; Elsing, M; Engel, J P; Erzen, B; Espirito-Santo, M C; Falk, E; Fanourakis, G K; Fassouliotis, D; Fayot, J; Feindt, Michael; Fenyuk, A; Ferrari, P; Ferrer, A; Ferrer-Ribas, E; Ferro, F; Fichet, S; Firestone, A; Flagmeyer, U; Föth, H; Fokitis, E; Fontanelli, F; Franek, B J; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gamblin, S; Gandelman, M; García, C; Gaspar, C; Gaspar, M; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Ghodbane, N; Gil, I; Glege, F; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; González-Caballero, I; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Grahl, J; Graziani, E; Green, C; Grimm, H J; Gris, P; Grosdidier, G; Grzelak, K; Günther, M; Guy, J; Hahn, F; Hahn, S; Haider, S; Hallgren, A; Hamacher, K; Hansen, J; Harris, F J; Hedberg, V; Heising, S; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Heuser, J M; Higón, E; Holmgren, S O; Holt, P J; Hoorelbeke, S; Houlden, M A; Hrubec, Josef; Huet, K; Hughes, G J; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, P E; Joram, C; Juillot, P; Kapusta, F; Karafasoulis, K; Katsanevas, S; Katsoufis, E C; Keränen, R; Kersevan, Borut P; Khomenko, B A; Khovanskii, N N; Kiiskinen, A P; King, B J; Kinvig, A; Kjaer, N J; Klapp, O; Klein, H; Kluit, P M; Kokkinias, P; Koratzinos, M; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Krammer, Manfred; Kriznic, E; Krstic, J; Krumshtein, Z; Kubinec, P; Kurowska, J; Kurvinen, K L; Lamsa, J; Lane, D W; Langefeld, P; Lapin, V; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Leinonen, L; Leisos, A; Leitner, R; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Lethuillier, M; Libby, J; Liko, D; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; Lopes, J H; López, J M; López-Fernandez, R; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Mahon, J R; Maio, A; Malek, A; Malmgren, T G M; Maltezos, S; Malychev, V; Mandl, F; Marco, J; Marco, R P; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Masik, J; Mazzucato, F; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; McPherson, G; Meroni, C; Meyer, W T; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Moch, M; Møller, R; Mönig, K; Monge, M R; Moreau, X; Morettini, P; Morton, G A; Müller, U; Münich, K; Mulders, M; Mulet-Marquis, C; Muresan, R; Murray, W J; Muryn, B; Myatt, Gerald; Myklebust, T; Naraghi, F; Nassiakou, M; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Némécek, S; Neufeld, N; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nikolenko, M; Nomokonov, V P; Normand, Ainsley; Nygren, A; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Orazi, G; Österberg, K; Ouraou, A; Paganoni, M; Paiano, S; Pain, R; Paiva, R; Palacios, J; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Pegoraro, M; Peralta, L; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Ratoff, P N; Read, A L; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Reinhardt, R; Renton, P B; Resvanis, L K; Richard, F; Rídky, J; Rinaudo, G; Røhne, O M; Romero, A; Ronchese, P; Rosenberg, E I; Rosinsky, P; Roudeau, Patrick; Rovelli, T; Royon, C; Ruhlmann-Kleider, V; Ruiz, A; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sampsonidis, D; Sannino, M; Schneider, H; Schwemling, P; Schwering, B; Schwickerath, U; Schyns, M A E; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Sekulin, R L; Shellard, R C; Sheridan, A; Siebel, M; Simard, L C; Simonetto, F; Sissakian, A N; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Sopczak, André; Sosnowski, R; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stanescu, C; Stanic, S; Stevenson, K; Stocchi, A; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tegenfeldt, F; Terranova, F; Thomas, J; Timmermans, J; Tinti, N; Tkatchev, L G; Todorova-Nová, S; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tzamarias, S; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; Van der Velde, C; van Apeldoorn, G W; van Dam, P; Van Doninck, W K; Van Eldik, J; Van Lysebetten, A; Van Vulpen, I B; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Verzi, V; Vilanova, D; Vitale, L; Vlasov, E; Vodopyanov, A S; Vollmer, C F; Voulgaris, G; Vrba, V; Wahlen, H; Walck, C; Weiser, C; Wicke, D; Wickens, J H; Wilkinson, G R; Winter, M; Witek, M; Wolf, G; Yi, J; Yushchenko, O P; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zucchelli, G C; Zumerle, G

1999-01-01

Infrared and collinear safe event shape distributions and their mean values are determined using the data taken at ve di erent centre of mass energies above $M_Z$ with the DELPHI detector at LEP. From the event shapes, the strong coupling $\\alpha_s$ is extracted in $O(\\alpha^2_s)$, NLLA and a combined scheme using hadronisation corrections evaluated with fragmentation model generators as well as using an analytical power ansatz. Comparing these measurements to those obtained at MZ, the energy dependence (running) of $\\alpha_s$ is accessible. The logarithmic energy slope of the inverse strong coupling is measured to be $d\\alpha_{s}^{-1}/d log(E_{cm}) = 1.39 \\pm 0.34(stat) \\pm 0.17(syst)$, in good agreement with the QCD expectation of 1.27.

Phase-Amplitude Coupling and Long-Range Phase Synchronization Reveal Frontotemporal Interactions during Visual Working Memory.

Science.gov (United States)

Daume, Jonathan; Gruber, Thomas; Engel, Andreas K; Friese, Uwe

2017-01-11

It has been suggested that cross-frequency phase-amplitude coupling (PAC), particularly in temporal brain structures, serves as a neural mechanism for coordinated working memory storage. In this magnetoencephalography study, we show that during visual working memory maintenance, temporal cortex regions, which exhibit enhanced PAC, interact with prefrontal cortex via enhanced low-frequency phase synchronization. Healthy human participants were engaged in a visual delayed match-to-sample task with pictures of natural objects. During the delay period, we observed increased spectral power of beta (20-28 Hz) and gamma (40-94 Hz) bands as well as decreased power of theta/alpha band (7-9 Hz) oscillations in visual sensory areas. Enhanced PAC between the phases of theta/alpha and the amplitudes of beta oscillations was found in the left inferior temporal cortex (IT), an area known to be involved in visual object memory. Furthermore, the IT was functionally connected to the prefrontal cortex by increased low-frequency phase synchronization within the theta/alpha band. Together, these results point to a mechanism in which the combination of PAC and long-range phase synchronization subserves enhanced large-scale brain communication. They suggest that distant brain regions might coordinate their activity in the low-frequency range to engage local stimulus-related processing in higher frequencies via the combination of long-range, within-frequency phase synchronization and local cross-frequency PAC. Working memory maintenance, like other cognitive functions, requires the coordinated engagement of brain areas in local and large-scale networks. However, the mechanisms by which spatially distributed brain regions share and combine information remain primarily unknown. We show that the combination of long-range, low-frequency phase synchronization and local cross-frequency phase-amplitude coupling might serve as a mechanism to coordinate memory processes across distant brain areas

Alpha Blockers

Science.gov (United States)

... quickly, but their effects last only a few hours. Long-acting medications take longer to work, but their effects last longer. Which alpha blocker is best for you depends on your health and the condition being treated. Alpha blockers are ...

Alpha Channeling in a Rotating Plasma

International Nuclear Information System (INIS)

Abraham J. Fetterman; Nathaniel J. Fisch

2008-01-01

The wave-particle α-channeling effect is generalized to include rotating plasma. Specifically, radio frequency waves can resonate with α particles in a mirror machine with E x B rotation to diffuse the α particles along constrained paths in phase space. Of major interest is that the α-particle energy, in addition to amplifying the RF waves, can directly enhance the rotation energy which in turn provides additional plasma confinement in centrifugal fusion reactors. An ancillary benefit is the rapid removal of alpha particles, which increases the fusion reactivity

Uranium analysis in Cypriot groundwaters by total alpha-radiometry and alpha-spectroscopy

International Nuclear Information System (INIS)

Efstathiou, Maria; Kiliari, Tasoula; Pashalidis, Ioannis

2011-01-01

Two different alpha-radiometric methods (e.g. alpha-spectroscopy and alpha-particle counting) have been applied to the determination of uranium in Cypriot groundwater samples after separation of the radionuclides by cation exchange using Chelex-100 and its electrodeposition on stainless steel planchettes. The data obtained were compared to show the advantages and disadvantages of the two radiometric methods, determine the alpha-radioactivity concentration and the radiation dose associated with the use of the studied groundwaters. Calibration of the methods was performed by means of uranium standard solutions and the corresponding data were used to evaluate linear range, detector efficiency, detection limits, value of the information obtained, and time of analysis of the methods. Comparison of the data obtained from calibration and natural sample measurements has shown that alpha-particle counting with a simple alpha-radiometer (equipped with a semiconductor detector) may offer only an activity value and not detailed information about the isotopic composition but it is the fastest method and the method of choice if only a screening method for the alpha-radioactivity measurement is required. Based on the alpha-radioactivity data, the corresponding radiation dose was estimated for situations where the groundwaters are used for drinking water purposes.

Effects of source and receiver locations in predicting room transfer functions by a phased beam tracing method

DEFF Research Database (Denmark)

Jeong, Cheol-Ho; Ih, Jeong-Guon

2012-01-01

The accuracy of a phased beam tracing method in predicting transfer functions is investigated with a special focus on the positions of the source and receiver. Simulated transfer functions for various source-receiver pairs using the phased beam tracing method were compared with analytical Green’s...

Alpha activity of 190 Pt isotope measured with CR-39 track detector

International Nuclear Information System (INIS)

Tavares, O.A.P.; Terranova, M.L.

1996-11-01

A new method to measure alpha activity of long-lived radioisotopes is reported. The method consists basically in using CR-39 track detectors in close contact with thick samples of the radioelement to be investigated. Accordingly, a long-term exposure experiment has been performed using metallic sheets of natural platinum to measure alpha activity of platinum 190 isotope. The half-life of platinum 190 has been obtained in good agreement with two recent theoretical half-life predictions. (author). 21 refs., 3 figs., 2 tabs

Predicting the start and maximum amplitude of solar cycle 24 using similar phases and a cycle grouping

International Nuclear Information System (INIS)

Wang Jialong; Zong Weiguo; Le Guiming; Zhao Haijuan; Tang Yunqiu; Zhang Yang

2009-01-01

We find that the solar cycles 9, 11, and 20 are similar to cycle 23 in their respective descending phases. Using this similarity and the observed data of smoothed monthly mean sunspot numbers (SMSNs) available for the descending phase of cycle 23, we make a date calibration for the average time sequence made of the three descending phases of the three cycles, and predict the start of March or April 2008 for cycle 24. For the three cycles, we also find a linear correlation of the length of the descending phase of a cycle with the difference between the maximum epoch of this cycle and that of its next cycle. Using this relationship along with the known relationship between the rise-time and the maximum amplitude of a slowly rising solar cycle, we predict the maximum SMSN of cycle 24 of 100.2 ± 7.5 to appear during the period from May to October 2012. (letters)

Comparison between Amnisure Placental Alpha Microglobulin-1 Rapid Immunoassay and Standard Diagnostic Methods for Detection of Rupture of Membranes

Directory of Open Access Journals (Sweden)

Beng Kwang Ng

2013-01-01

Full Text Available Objective. To determine the diagnostic accuracy of placental alpha microglobulin-1 assay and standard diagnostic methods for detecting rupture of membrane. Study Design. Prospective diagnostic study, between June 2011 to November 2011 at a tertiary centre. Initial evaluation included both the standard diagnostic methods for rupture of membranes and placental alpha microglobulin-1 immunoassay. The actual rupture of membranes was diagnosed on review of the medical records after delivery (absence of membrane or a positive pad chart. Main Outcome Measures. Placental alpha microglobulin-1 immunoassay and standard diagnostic methods for diagnosis of rupture of membrane. Results. A total of 211 patients were recruited. At initial presentation, 187 patients (88.6% had ruptured membranes, while 24 patients (11.4% had intact membranes. Placental alpha microglobulin-1 immunoassay confirmed rupture of membranes at initial presentation with a sensitivity of 95.7% (179 of 187, specificity of 100% (24 of 24, positive predictive value of 100% (179 of 179, and negative predictive value of 75.0% (24 of 32. By comparison, the conventional standard diagnostic methods had a sensitivity of 78.1% (146 of 187, specificity of 100% (24 of 24, positive predictive value of 100% (146 of 146, and negative predictive value of 36.9% (24 of 65 in diagnosing rupture of membrane. Conclusion. Placental alpha-microglobulin-1 immunoassay is a rapid and accurate method for confirming the diagnosis of rupture of membrane. It was superior to conventional standard diagnostic methods (pooling, nitrazine, and ferning, the nitrazine test alone or fern test alone.

Attention Modulates TMS-Locked Alpha Oscillations in the Visual Cortex.

Science.gov (United States)

Herring, Jim D; Thut, Gregor; Jensen, Ole; Bergmann, Til O

2015-10-28

Cortical oscillations, such as 8-12 Hz alpha-band activity, are thought to subserve gating of information processing in the human brain. While most of the supporting evidence is correlational, causal evidence comes from attempts to externally drive ("entrain") these oscillations by transcranial magnetic stimulation (TMS). Indeed, the frequency profile of TMS-evoked potentials (TEPs) closely resembles that of oscillations spontaneously emerging in the same brain region. However, it is unclear whether TMS-locked and spontaneous oscillations are produced by the same neuronal mechanisms. If so, they should react in a similar manner to top-down modulation by endogenous attention. To test this prediction, we assessed the alpha-like EEG response to TMS of the visual cortex during periods of high and low visual attention while participants attended to either the visual or auditory modality in a cross-modal attention task. We observed a TMS-locked local oscillatory alpha response lasting several cycles after TMS (but not after sham stimulation). Importantly, TMS-locked alpha power was suppressed during deployment of visual relative to auditory attention, mirroring spontaneous alpha amplitudes. In addition, the early N40 TEP component, located at the stimulation site, was amplified by visual attention. The extent of attentional modulation for both TMS-locked alpha power and N40 amplitude did depend, with opposite sign, on the individual ability to modulate spontaneous alpha power at the stimulation site. We therefore argue that TMS-locked and spontaneous oscillations are of common neurophysiological origin, whereas the N40 TEP component may serve as an index of current cortical excitability at the time of stimulation. Copyright © 2015 Herring et al.

Influence of fast alpha diffusion and thermal alpha buildup on tokamak reactor performance

International Nuclear Information System (INIS)

Uckan, N.A.; Tolliver, J.S.; Houlberg, W.A.; Attenberger, S.E.

1988-01-01

The effect of fast alpha diffusion and thermal alpha accumulation on the confinement capability of a candidate Engineering Test Reactor plasma (Tokamak Ignition/Burn Experimental Reactor) in achieving ignition and steady-state driven operation has been assessed using both global and 1-1/2-dimensional transport models. Estimates are made of the threshold for radial diffusion of fast alphas and thermal alpha buildup. It is shown that a relatively low level of radial transport, when combined with large gradients in the fast alpha density, leads to a significant radial flow with a deleterious effect on plasma performance. Similarly, modest levels of thermal alpha concentration significantly influence the ignition and steady-state burn capability

Comparative study of the creep behaviour of single crystals and polycrystals of alpha uranium; Etude comparee du comportement au fluage de l'uranium alpha mono et polycristallin

Energy Technology Data Exchange (ETDEWEB)

Andre, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-03-01

changement de phase a l'etat solide. La deformation s'effectue essentiellement par glissement. La polygonisation inherente a l'obtention de ces monocristaux est extremement stable et la desorientation entre sous-grains augmente avec la deformation. La valeur de l'energie d'activation pour le fluage est superieure a celle des polycristaux. Ces resultats montrent l'influence de la polygonisation introduite par le passage de la phase beta a la phase alpha sur le comportement au fluage de l'uranium alpha.

Magnetic properties of {alpha}-Fe and Fe{sub 3}C nanowires

Energy Technology Data Exchange (ETDEWEB)

Lutz, M U; Weissker, U; Wolny, F; Mueller, C; Loeffler, M; Muehl, T; Leonhardt, A; Buechner, B; Klingeler, R, E-mail: m.lutz@ifw-dresden.d [Leibniz Institute for Solid State and Materials Research IFW Dresden, Helmholtzstrasse 20, 01069 Dresden (Germany)

2010-01-01

The magnetic properties of single domain {alpha}-Fe and Fe{sub 3}C nanowires encapsulated within Multi Walled Carbon Nanotubes (MWNT) are investigated with a Magnetic Force Microscope (MFM). The wires are formed during the Chemical Vapour Deposition growth process, partially filling the hollow center of the MWNTs. The wires have a diameter variation of 10-60nm and can be several {mu}m long. The phase and crystal orientation of the filling relative to the long tube axis are probed by Transmission Electron Microscopy. The remanent magnetization states of the wires are investigated by MFM imaging. The {alpha}-Fe wires show shape dominated magnetization along the tube axis, whereas the FesC wires show a perpendicular magnetization imposed by magneto-crystalline anisotropy. Switching fields of {alpha}-Fe nanowires are determined by the application of an in-situ magnetic field, revealing a tip triggered magnetization reversal by localized nucleation.

HPLC Analysis of [Alpha]- and [Beta]-Acids in Hops

Science.gov (United States)

Danenhower, Travis M.; Force, Leyna J.; Petersen, Kenneth J.; Betts, Thomas A.; Baker, Gary A.

2008-01-01

Hops have been used for centuries to impart aroma and bitterness to beer. The cones of the female hop plant contain both essential oils, which include many of the fragrant components of hops, and a collection of compounds known as [alpha]- and [beta]-acids that are the precursors to bittering agents. In order for brewers to predict the ultimate…

Stereospecific enzymatic transformation of alpha-ketoglutarate to (2S,3R)-3-methyl glutamate during acidic lipopeptide biosynthesis.

Science.gov (United States)

Mahlert, Christoph; Kopp, Florian; Thirlway, Jenny; Micklefield, Jason; Marahiel, Mohamed A

2007-10-03

The acidic lipopeptides, including the calcium-dependent antibiotics (CDA), daptomycin, and A54145, are important macrocyclic peptide natural products produced by Streptomyces species. All three compounds contain a 3-methyl glutamate (3-MeGlu) as the penultimate C-terminal residue, which is important for bioactivity. Here, biochemical in vitro reconstitution of the 3-MeGlu biosynthetic pathway is presented, using exclusively enzymes from the CDA producer Streptomyces coelicolor. It is shown that the predicted 3-MeGlu methyltransferase GlmT and its homologues DptI from the daptomycin producer Streptomyces roseosporus and LptI from the A54145 producer Streptomyces fradiae do not methylate free glutamic acid, PCP-bound glutamate, or Glu-containing CDA in vitro. Instead, GlmT, DptI, and LptI are S-adenosyl methionine (SAM)-dependent alpha-ketoglutarate methyltransferases that catalyze the stereospecific methylation of alpha-ketoglutarate (alphaKG) leading to (3R)-3-methyl-2-oxoglutarate. Subsequent enzyme screening identified the branched chain amino acid transaminase IlvE (SCO5523) as an efficient catalyst for the transformation of (3R)-3-methyl-2-oxoglutarate into (2S,3R)-3-MeGlu. Comparison of reversed-phase HPLC retention time of dabsylated 3-MeGlu generated by the coupled enzymatic reaction with dabsylated synthetic standards confirmed complete stereocontrol during enzymatic catalysis. This stereospecific two-step conversion of alphaKG to (2S,3R)-3-MeGlu completes our understanding of the biosynthesis and incorporation of beta-methylated amino acids into the nonribosomal lipopeptides. Finally, understanding this pathway may provide new possibilities for the production of modified peptides in engineered microbes.

[Age-related change in the alpha-tocopherolquinone/alpha-tocopherol ratio in the rat erythrocyte membrane].

Science.gov (United States)

Yanagawa, K; Takeda, H; Matsumiya, T; Takasaki, M

1999-05-01

alpha-Tocopherol (alpha-Toc), a lipophilic phenolic antioxidant that is localized mainly in the biomembrane, protects cells against oxidation-associated cytotoxicity by prevention of membrane lipid peroxidation, maintenance of the redox balance intracellular thiols and stabilization of the membrane structure. We investigated the age-related changes in redox dynamics of alpha-Toc in plasma and erythrocyte membrane of an elderly (66 weeks old) and young group (10 weeks old). Total, alpha-, beta + gamma-, delta-Toc and alpha-tocopherolquinone (alpha-TocQ) in plasma and erythrocyte membrane were determined by high-performance liquid chromatography (HPLC) with a series of multiple coulometric working electrodes (CWE). Rat venous blood sample was divided into plasma and erythrocyte layers by centrifugation, and then erythrocyte membrane sample was prepared according to the method of Dodge et al. under a stream of nitrogen. In plasma, total and alpha-Toc concentrations were increased, and beta + gamma-, delta-Toc and alpha-TocQ concentrations were decreased age-dependently. In the erythrocyte membrane, total, alpha-TocQ concentrations and three fractions of tocopherols decreased age-dependently. Also, a decrease in the alpha-TocQ/alpha-Toc ratio in erythrocyte membrane was observed in the elderly group. These findings suggest that the alpha-Toc uptake in erythrocyte membrane and utilization rate of alpha-Toc in erythrocyte membrane decline age-dependently. This decline may promote membrane lipid peroxidation. alpha-Toc redox dynamics in erythrocyte membrane were useful to investigate the pathophysiology of aging mechanisms related to oxidative stress.

Anticytokine treatment of established type II collagen-induced arthritis in DBA/1 mice: a comparative study using anti-TNFalpha, anti-IL-1alpha/beta and IL-1Ra.

NARCIS (Netherlands)

Joosten, L.A.B.; Helsen, M.M.A.; Loo, F.A.J. van de; Berg, W.B. van den

2008-01-01

OBJECTIVE: To examine the role of tumor necrosis factor alpha (TNF alpha), interleukin-1 alpha (IL-1 alpha), and IL-1 beta in collagen-induced arthritis (CIA), immediately after onset and during the phase of established arthritis. METHODS: Male DBA/1 mice with collagen-induced arthritis were treated

Nearest-neighbor Kitaev exchange blocked by charge order in electron doped $\\alpha$-RuCl$_{3}$

OpenAIRE

Koitzsch, A.; Habenicht, C.; Mueller, E.; Knupfer, M.; Buechner, B.; Kretschmer, S.; Richter, M.; Brink, J. van den; Boerrnert, F.; Nowak, D.; Isaeva, A.; Doert, Th.

2017-01-01

A quantum spin-liquid might be realized in $\\alpha$-RuCl$_{3}$, a honeycomb-lattice magnetic material with substantial spin-orbit coupling. Moreover, $\\alpha$-RuCl$_{3}$ is a Mott insulator, which implies the possibility that novel exotic phases occur upon doping. Here, we study the electronic structure of this material when intercalated with potassium by photoemission spectroscopy, electron energy loss spectroscopy, and density functional theory calculations. We obtain a stable stoichiometry...

Serum alpha-fetoprotein response can predict prognosis in hepatocellular carcinoma patients undergoing radiofrequency ablation therapy

Energy Technology Data Exchange (ETDEWEB)

Kao, W.-Y. [Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, Taiwan (China); Chiou, Y.-Y., E-mail: yychiou@vghtpe.gov.tw [Department of Radiology, Taipei Veterans General Hospital, Taiwan (China); Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Hung, H.-H. [Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, Taiwan (China); Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Su, C.-W., E-mail: cwsu2@vghtpe.gov.tw [Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, Taiwan (China); Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Chou, Y.-H. [Department of Radiology, Taipei Veterans General Hospital, Taiwan (China); Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Wu, J.-C. [Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Department of Medical Research and Education, Taipei Veterans General Hospital, Taiwan (China); Huo, T.-I. [Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, Taiwan (China); Institute of Pharmacology, School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Huang, Y.-H. [Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, Taiwan (China); Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Wu, W.-C. [Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, Taiwan (China)

2012-05-15

Aims: To evaluate the clinical inference of serum alpha-fetoprotein (AFP) response in hepatocellular carcinoma (HCC) patients undergoing percutaneous radiofrequency ablation (RFA). Materials and methods: Three hundred and thirteen previously untreated HCC patients were enrolled in the study. The optimal AFP response was defined as >20% decrease from baseline after 1 month of RFA for those with a baseline AFP level of {>=}100 ng/ml. The impact of AFP response on prognosis was analysed and prognostic factors were assessed. Results: After a median follow-up of 26.7 {+-} 19.1 months, 49 patients died and 264 patients were alive. The cumulative 5 year survival rates were 75.3 and 57.4% in patients with an initial AFP of <100 ng/ml and {>=}100 ng/ml, respectively (p = 0.003). In the 58 patients with a baseline AFP of {>=}100 ng/ml and initial completed tumour necrosis after RFA, the cumulative 5 year survival rates were 62.4 and 25.7% in optimal and non-optimal AFP responders, respectively (p = 0.001). By multivariate analysis, the prothrombin time international normalized ratio >1.1 (p = 0.009), non-optimal AFP response (p = 0.023), and creatinine >1.5 mg/dl (p = 0.021) were independent risk factors predictive of poor overall survival. Besides, the cumulative 5 year recurrence rates were 83.4 and 100% in optimal and non-optimal AFP responders, respectively (p < 0.001). Multivariate analysis demonstrated platelet count {<=}10{sup 5}/mm{sup 3} (p = 0.048), tumour size >2 cm (p = 0.027), and non-optimal AFP response (p < 0.001) were independent risk factors associated with tumour recurrence after RFA. Conclusions: Serum AFP response may be a useful marker for predicting prognosis in HCC patients undergoing RFA.

Three-Dimensional Conformal Radiotherapy in Prostate Cancer Patients: Rise in Interleukin 6 (IL-6) but not IL-2, IL-4, IL-5, Tumor Necrosis Factor-{alpha}, MIP-1-{alpha}, and LIF Levels

Energy Technology Data Exchange (ETDEWEB)

Oliveira Lopes, Carlos [Universidade do Vale do Paraiba, Centro de Oncologia Radioterapica do Vale do Paraiba, Universidade do Vale do Paraiba Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraiba, Sao Jose dos Campos, Sao Paulo (Brazil); Callera, Fernando, E-mail: fcallera@gmail.com [Centro de Hematologia Onco-hematologia e Transplantes de Medula Ossea do Vale do Paraiba, Sao Paulo (Brazil)

2012-03-15

Purpose: To investigate the effect of radiotherapy (RT) on serum levels of interleukin-2 (IL-2), IL-4, IL-5, IL-6, tumor necrosis factor alpha (TNF-{alpha}), macrophage inflammatory protein-1-alpha (MIP-1-{alpha}) and leukemia inhibitory factor (LIF) in patients with prostate cancer. Methods and Materials: Forty eight patients with prostate cancer received three-dimensional conformal blocking radiation therapy with a linear accelerator. IL-2, IL-4, IL-5, IL-6, TNF-{alpha}, MIP-1-{alpha}, and LIF levels were measured by the related immunoassay kit 1 day before the beginning of RT and during RT at days 15 and 30. Results: The mean IL-2 values were elevated before and during the RT in contrast with those of IL-4, IL-5, IL-6, TNF-{alpha}, MIP-1-{alpha}, and LIF, which were within the normal range under the same conditions. Regarding markers IL-2, IL-4, IL-5, TNF-{alpha}, MIP-1-{alpha}, and LIF, comparisons among the three groups (before treatment and 15 and 30 days during RT) did not show significant differences. Although values were within the normal range, there was a significant rise in IL-6 levels at day 15 of RT (p = 0.0049) and a decline at day 30 to levels that were similar to those observed before RT. Conclusions: IL-6 appeared to peak after 15 days of RT before returning to pre-RT levels. In contrast, IL-2, IL-4, IL-5, TNF-{alpha}, MIP-1-{alpha}, and LIF levels were not sensitive to irradiation. The increased levels of IL-6 following RT without the concurrent elevation of other cytokines involved in the acute phase reaction did not suggest a classical inflammatory response to radiation exposure. Further studies should be designed to elucidate the role of IL-6 levels in patients with prostate cancer treated with RT.

Ultraviolet photometry from the orbiting astronomical observatory. XVI - The stellar Lyman-alpha absorption line

Science.gov (United States)

Savage, B. D.; Panek, R. J.

1974-01-01

The stellar Lyman-alpha line at 1216 A was observed in 29 lightly reddened stars of spectral type B2.5 to B9 by a far-UV spectrophotometer on OAO-2. The equivalent widths obtained range from 15 A at type B2.5 to 65 A at type B8; in the late-B stars, the L-alpha line removes 2 to 3% of the total stellar flux. In this sampling, the strength of the L-alpha line correlates well with measures of the Balmer discontinuity and Balmer line strengths; luminosity classification does not seem to affect the line strength. The observed line widths also agree with the predictions of Mihala's grid of non-LTE model atmospheres. In some cases, the L-alpha line influences the interstellar column densities reported in the interstellar OAO-2 L-alpha survey. Hence, these data toward lightly reddened B2 and B1.5 stars should be regarded as upper limits only.

Prediction of phase equilibria and thermal analysis in the Bi-Cu-Pb ternary system

Energy Technology Data Exchange (ETDEWEB)

Manasijevic, Dragan [University of Belgrade, Technical Faculty, VJ 12, 19210 Bor (Serbia); Mitovski, Aleksandra, E-mail: amitovski@tf.bor.ac.rs [University of Belgrade, Technical Faculty, VJ 12, 19210 Bor (Serbia); Minic, Dusko [University of Pristina, Faculty of Technical Sciences, 38220 Kosovska Mitrovica (Serbia); Zivkovic, Dragana; Marjanovic, Sasa [University of Belgrade, Technical Faculty, VJ 12, 19210 Bor (Serbia); Todorovic, Radisa [Institute of Mining and Metallurgy, Zeleni Bulevar 35, 19210 Bor (Serbia); Balanovic, Ljubisa [University of Belgrade, Technical Faculty, VJ 12, 19210 Bor (Serbia)

2010-05-20

The knowledge about phase diagram of the Bi-Cu-Pb ternary system is of importance in development of copper-lead based bearing materials, soldering and in refining of copper and lead. In this work, the phase diagram of the Bi-Cu-Pb ternary system was calculated by the CALPHAD method using binary thermodynamic parameters included in the COST 531 database. The results include liquidus projection, invariant equilibria and three vertical sections with molar ratio Cu:Pb = 1, Cu:Pb = 1:3 and Bi:Cu = 1. Alloys, with compositions along three predicted vertical sections, were measured using differential scanning calorimetry (DSC). The experimentally determined phase transition temperatures were compared with calculated results and good mutual agreement was noticed.

Prediction of phase equilibria and thermal analysis in the Bi-Cu-Pb ternary system

International Nuclear Information System (INIS)

Manasijevic, Dragan; Mitovski, Aleksandra; Minic, Dusko; Zivkovic, Dragana; Marjanovic, Sasa; Todorovic, Radisa; Balanovic, Ljubisa

2010-01-01

The knowledge about phase diagram of the Bi-Cu-Pb ternary system is of importance in development of copper-lead based bearing materials, soldering and in refining of copper and lead. In this work, the phase diagram of the Bi-Cu-Pb ternary system was calculated by the CALPHAD method using binary thermodynamic parameters included in the COST 531 database. The results include liquidus projection, invariant equilibria and three vertical sections with molar ratio Cu:Pb = 1, Cu:Pb = 1:3 and Bi:Cu = 1. Alloys, with compositions along three predicted vertical sections, were measured using differential scanning calorimetry (DSC). The experimentally determined phase transition temperatures were compared with calculated results and good mutual agreement was noticed.

Extreme Environment Damage Index and Accumulation Model for CMC Laminate Fatigue Life Prediction, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Materials Research & Design (MR&D) is proposing in the SBIR Phase II an effort to develop a tool for predicting the fatigue life of C/SiC composite...

Identification of a novel bile acid in swans, tree ducks, and geese: 3alpha,7alpha,15alpha-trihydroxy-5beta-cholan-24-oic acid.

Science.gov (United States)

Kakiyama, Genta; Iida, Takashi; Goto, Takaaki; Mano, Nariyasu; Goto, Junichi; Nambara, Toshio; Hagey, Lee R; Schteingart, Claudio D; Hofmann, Alan F

2006-07-01

By HPLC, a taurine-conjugated bile acid with a retention time different from that of taurocholate was found to be present in the bile of the black-necked swan, Cygnus melanocoryphus. The bile acid was isolated and its structure, established by (1)H and (13)C NMR and mass spectrometry, was that of the taurine N-acyl amidate of 3alpha,7alpha,15alpha-trihydroxy-5beta-cholan-24-oic acid. The compound was shown to have chromatographic and spectroscopic properties that were identical to those of the taurine conjugate of authentic 3alpha,7alpha,15alpha-trihydroxy-5beta-cholan-24-oic acid, previously synthesized by us from ursodeoxycholic acid. By HPLC, the taurine conjugate of 3alpha,7alpha,15alpha-trihydroxy-5beta-cholan-24-oic acid was found to be present in 6 of 6 species in the subfamily Dendrocygninae (tree ducks) and in 10 of 13 species in the subfamily Anserinae (swans and geese) but not in other subfamilies in the Anatidae family. It was also not present in species from the other two families of the order Anseriformes. 3alpha,7alpha,15alpha-Trihydroxy-5beta-cholan-24-oic acid is a new primary bile acid that is present in the biliary bile acids of swans, tree ducks, and geese and may be termed 15alpha-hydroxy-chenodeoxycholic acid.

Maternal executive function, heart rate, and EEG alpha reactivity interact in the prediction of harsh parenting.

Science.gov (United States)

Deater-Deckard, Kirby; Bell, Martha Ann

2017-02-01

Do physiological and behavioral performance indicators of effortful cognitive self-regulation converge additively or interactively in their statistical prediction of individual differences in harsh parenting? To answer this question, we examined heart rate (HR) and electroencephalography alpha (α) reactivity during executive function (EF) tasks, along with observed and self-reported indicators of harsh parenting. A socioeconomically diverse sample of 115 mothers with 3- to 7-year-old children completed questionnaires and a laboratory visit. Three quarters of the mothers showed typical patterns of task reactivity that were interpretable (i.e., increases in HR and decreases in α). Among them, we found no evidence to suggest that variance in harsh parenting was associated with magnitude of HR or α reactivity independently. Instead, the physiological variables interacted to enhance the EF statistical effect. EF explained one third of the variance in harsh parenting among mothers showing the largest α decreases when accompanied by modest to moderate (rather than substantial) HR increases. Physiological indicators can clarify the role and estimation of the strength of the effect of direct behavioral measures of cognitive regulation in the etiology of harsh parenting behaviors. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Crossing symmetry in Alpha space

CERN Multimedia

CERN. Geneva

2017-01-01

The conformal bootstrap program aims to catalog all conformal field theories (second-order phase transitions) in D dimensions. Despite its ambitious scope much progress has been made over the past decade, e.g. in computing critical exponents for the 3D O(N) models to high precision. At this stage, analytic methods to explore the CFT landscape are not as well developed. In this talk I will describe a new mathematical framework for the bootstrap known as "alpha space", which reduces crossing symmetry to a set of integral equations. Based on arXiv:1702.08471 (with Balt van Rees) and arXiv:1703.08159.

Low-Complexity Model Predictive Control of Single-Phase Three-Level Rectifiers with Unbalanced Load

DEFF Research Database (Denmark)

Ma, Junpeng; Song, Wensheng; Wang, Xiongfei

2018-01-01

The fluctuation of the neutral-point potential in single-phase three-level rectifiers leads to coupling between the line current regulation and dc-link voltage balancing, deteriorating the quality of line current. For addressing this issue, this paper proposes a low-complexity model predictive...

Validation of model predictions of pore-scale fluid distributions during two-phase flow

Science.gov (United States)

Bultreys, Tom; Lin, Qingyang; Gao, Ying; Raeini, Ali Q.; AlRatrout, Ahmed; Bijeljic, Branko; Blunt, Martin J.

2018-05-01

Pore-scale two-phase flow modeling is an important technology to study a rock's relative permeability behavior. To investigate if these models are predictive, the calculated pore-scale fluid distributions which determine the relative permeability need to be validated. In this work, we introduce a methodology to quantitatively compare models to experimental fluid distributions in flow experiments visualized with microcomputed tomography. First, we analyzed five repeated drainage-imbibition experiments on a single sample. In these experiments, the exact fluid distributions were not fully repeatable on a pore-by-pore basis, while the global properties of the fluid distribution were. Then two fractional flow experiments were used to validate a quasistatic pore network model. The model correctly predicted the fluid present in more than 75% of pores and throats in drainage and imbibition. To quantify what this means for the relevant global properties of the fluid distribution, we compare the main flow paths and the connectivity across the different pore sizes in the modeled and experimental fluid distributions. These essential topology characteristics matched well for drainage simulations, but not for imbibition. This suggests that the pore-filling rules in the network model we used need to be improved to make reliable predictions of imbibition. The presented analysis illustrates the potential of our methodology to systematically and robustly test two-phase flow models to aid in model development and calibration.

In vitro and preclinical targeted alpha therapy for cancer

International Nuclear Information System (INIS)

Allen, B.J.; Rizvi, S.; Li, Y.; Tian, Z.; University of Wollongong, NSW; Ranson, M.; Russell, P.J.

2000-01-01

Full text: Targeted Alpha therapy (TAT) offers the potential to inhibit the growth of micrometastases by selectively killing isolated and preangiogenic clusters of cancer cells. The alpha emitting radioisotope Bi-213 is produced by generator and chelated to a cancer affined monoclonal antibody or protein to form the alpha-conjugate (AC) against melanoma, leukaemia, colorectal, bladder, breast and prostate cancers. These ACs are tested for stability, specificity and cytotoxicity. Subcutaneous inoculation of 1.5 million cells into the flanks of nude mice causes tumours to grow in all mice. The tumour growth is compared between untreated controls, nonspecific RIC and specific RIC, for local (subcutaneous) and systemic (tail vein or intraperitoneal) injection models. Results: Stable alpha-ACs can be produced which are highly specific and cytotoxic in vitro. Local TAT at 2 days post-inoculation completely prevents tumour formation for all cancers tested so far. Local TAT can also completely regress (11/12) sc melanoma but is less successful for breast and prostate cancers. Systemic TAT inhibits the growth of sc melanoma xenografts. These results point to the potential application of local TAT and systemic TAT in the management of these cancers. A phase 1 and 2 clinical trial is planned for local TAT of sc recurrent melanoma. Copyright (2000) Australasian College of Physical Scientists and Engineers in Medicine

A randomized clinical trial of alpha(1)-antitrypsin augmentation therapy.

Science.gov (United States)

Dirksen, A; Dijkman, J H; Madsen, F; Stoel, B; Hutchison, D C; Ulrik, C S; Skovgaard, L T; Kok-Jensen, A; Rudolphus, A; Seersholm, N; Vrooman, H A; Reiber, J H; Hansen, N C; Heckscher, T; Viskum, K; Stolk, J

1999-11-01

We have investigated whether restoration of the balance between neutrophil elastase and its inhibitor, alpha(1)-antitrypsin, can prevent the progression of pulmonary emphysema in patients with alpha(1)-antitrypsin deficiency. Twenty-six Danish and 30 Dutch ex-smokers with alpha(1)-antitrypsin deficiency of PI*ZZ phenotype and moderate emphysema (FEV(1) between 30% and 80% of predicted) participated in a double-blind trial of alpha(1)-antitrypsin augmentation therapy. The patients were randomized to either alpha(1)-antitrypsin (250 mg/kg) or albumin (625 mg/kg) infusions at 4-wk intervals for at least 3 yr. Self-administered spirometry performed every morning and evening at home showed no significant difference in decline of FEV(1) between treatment and placebo. Each year, the degree of emphysema was quantified by the 15th percentile point of the lung density histogram derived from computed tomography (CT). The loss of lung tissue measured by CT (mean +/- SEM) was 2.6 +/- 0.41 g/L/yr for placebo as compared with 1.5 +/- 0.41 g/L/yr for alpha(1)-antitrypsin infusion (p = 0.07). Power analysis showed that this protective effect would be significant in a similar trial with 130 patients. This is in contrast to calculations based on annual decline of FEV(1) showing that 550 patients would be needed to show a 50% reduction of annual decline. We conclude that lung density measurements by CT may facilitate future randomized clinical trials of investigational drugs for a disease in which little progress in therapy has been made in the past 30 yr.

Validation of the alpha-fetoprotein model for hepatocellular carcinoma recurrence after transplantation in an Asian population.

Science.gov (United States)

Rhu, Jinsoo; Kim, Jong Man; Choi, Gyu Seong; Kwon, Choon Hyuck David; Joh, Jae-Won

2018-02-20

This study was designed to validate the alpha-fetoprotein model for predicting recurrence after liver transplantation in Korean hepatocellular carcinoma patients. Patients who underwent liver transplantation for hepatocellular carcinoma at Samsung Medical Center between 2007 and 2015 were included. Recurrence, overall survival, and disease-specific survival of patients divided by both the Milan criteria and the alpha-fetoprotein model were compared using Kaplan-Meier log-rank test. The predictability of the alpha-fetoprotein model compared to the Milan criteria was tested by means of net reclassification improvement analysis applied to patients with a follow-up of at least 2 years. A total of 400 patients were included in the study. Patients within Milan criteria had 5-year recurrence, and overall survival rates of 20.9% and 76.3% respectively, compared to corresponding rates of 50.3% and 55.7%, respectively, for patients who were beyond Milan criteria. Alpha-fetoprotein model low risk patients had 5-year recurrence and overall survival rates of 21.1% and 76.2%, respectively, compared to corresponding rates of 57.7% and 52.2%, respectively, in high risk patients (P<0.001, all). Although overall net reclassification improvements were statistically nonsignificant for recurrence (NRI=1.7%, Z=0.30, p=0.7624), and overall survival (NRI=9.0%, Z=1.60, p=0.1098), they were significantly better for predicting no recurrence (NRI=6.6%, Z=3.16, p=0.0016) and no death. (NRI=7.7%, Z=3.65, p=0.0003) CONCLUSIONS: The alpha-fetoprotein model seems to be a promising tool for liver transplantation candidacy, but further investigation is needed.

Buffett's Alpha

DEFF Research Database (Denmark)

Frazzini, Andrea; Kabiller, David; Heje Pedersen, Lasse

Berkshire Hathaway has realized a Sharpe ratio of 0.76, higher than any other stock or mutual fund with a history of more than 30 years, and Berkshire has a significant alpha to traditional risk factors. However, we find that the alpha becomes insignificant when controlling for exposures to Betting...

Sterol synthesis. A novel reductive rearrangement of an alpha,beta-unsaturated steroidal epoxide; a new chemical synthesis of 5alpha-cholest-8(14)-en-3beta, 15alpha-diol.

Science.gov (United States)

Parish, E J; Schroepfer, G J

1977-04-01

Reduction of 3beta-benzoyloxy-14alpha,15alpha-epoxy-5alpha-cholest-7-ene with either lithium triethylboro-hydride or lithium aluminum hydride (4 molar excess) gave 5-alpha-cholest-8(14)-en-3beta,15alpha-diol in high yield. Reduction of the epoxy ester with lithium triethylborodeuteride or lithium aluminum deuteride (4 molar excess) gave [7alpha-2-H]-5alpha-cholest-8(14)-en-3beta,15alpha-diol. Reduction of 2beta-benzoyloxy-14alpha,15alpha-epoxy-5alpha-cholest-7-ene with a large excess (24 molar excess) of lithium aluminum hydride gave, in addition to the expected 5alpha-cholest-8(14)-en-3beta,15alpha-diol, a significant yield (33%) of 5alpha-cholest-8(14)-en-3beta-o1. Reduction of the epoxy ester with a large excess (24 molar excess) of lithium aluminum deuteride gave [7alpha-2H]-5alpha-cholest-8(14)-en-3beta,15alpha-diol and 5alpha-cholest-8(14)-en-3beta-o1 which contained two atoms of stably bound deuterium.

Progesterone modulation of alpha5 nAChR subunits influences anxiety-related behavior during estrus cycle.

Science.gov (United States)

Gangitano, D; Salas, R; Teng, Y; Perez, E; De Biasi, M

2009-06-01

Smokers often report an anxiolytic effect of cigarettes. In addition, stress-related disorders such as anxiety, post-traumatic stress syndrome and depression are often associated with chronic nicotine use. To study the role of the alpha5 nicotinic acetylcholine receptor subunit in anxiety-related responses, control and alpha5 subunit null mice (alpha5(-/-)) were subjected to the open field activity (OFA), light-dark box (LDB) and elevated plus maze (EPM) tests. In the OFA and LDB, alpha5(-/-) behaved like wild-type controls. In the EPM, female alpha5(-/-) mice displayed an anxiolytic-like phenotype, while male alpha5(-/-) mice were undistinguishable from littermate controls. We studied the hypothalamus-pituitary-adrenal axis by measuring plasma corticosterone and hypothalamic corticotropin-releasing factor. Consistent with an anxiolytic-like phenotype, female alpha5(-/-) mice displayed lower basal corticosterone levels. To test whether gonadal steroids regulate the expression of alpha5, we treated cultured NTera 2 cells with progesterone and found that alpha5 protein levels were upregulated. In addition, brain levels of alpha5 mRNA increased upon progesterone injection into ovariectomized wild-type females. Finally, we tested anxiety levels in the EPM during the estrous cycle. The estrus phase (when progesterone levels are low) is anxiolytic-like in wild-type mice, but no cycle-dependent fluctuations in anxiety levels were found in alpha5(-/-) females. Thus, alpha5-containing neuronal nicotinic acetylcholine receptors may be mediators of anxiogenic responses, and progesterone-dependent modulation of alpha5 expression may contribute to fluctuations in anxiety levels during the ovarian cycle.

Immunostimulatory effects of natural human interferon-alpha (huIFN-alpha) on carps Cyprinus carpio L.

Science.gov (United States)

Watanuki, Hironobu; Chakraborty, Gunimala; Korenaga, Hiroki; Kono, Tomoya; Shivappa, R B; Sakai, Masahiro

2009-10-15

Human interferon-alpha (huIFN-alpha) is an important immunomodulatory substance used in the treatment and prevention of numerous infectious and immune-related diseases in animals. However, the immunostimulatory effects of huIFN-alpha in fish remain to be investigated. In the current study, the immune responses of the carp species Cyprinus carpio L. to treatment with huIFN-alpha were analyzed via measurement of superoxide anion production, phagocytic activity and the expression of cytokine genes including interleukin-1beta, tumor necrosis factor-alpha and interleukin 10. Low doses of huIFN-alpha were administered orally once a day for 3 days, and sampling was carried out at 1, 3 and 5 days post-treatment. Our results indicate that a low dose of huIFN-alpha significantly increased phagocytic activity and superoxide anion production in the carp kidney. The huIFN-alpha-treated fish also displayed a significant upregulation in cytokine gene expression. The current study demonstrates the stimulatory effects of huIFN-alpha on the carp immune system and highlights the immunomodulatory role of huIFN-alpha in fish.

Gradient retention prediction of acid-base analytes in reversed phase liquid chromatography: a simplified approach for acetonitrile-water mobile phases.

Science.gov (United States)

Andrés, Axel; Rosés, Martí; Bosch, Elisabeth

2014-11-28

In previous work, a two-parameter model to predict chromatographic retention of ionizable analytes in gradient mode was proposed. However, the procedure required some previous experimental work to get a suitable description of the pKa change with the mobile phase composition. In the present study this previous experimental work has been simplified. The analyte pKa values have been calculated through equations whose coefficients vary depending on their functional group. Forced by this new approach, other simplifications regarding the retention of the totally neutral and totally ionized species also had to be performed. After the simplifications were applied, new prediction values were obtained and compared with the previously acquired experimental data. The simplified model gave pretty good predictions while saving a significant amount of time and resources. Copyright © 2014 Elsevier B.V. All rights reserved.

Drugs interacting with alpha adrenoceptors

NARCIS (Netherlands)

van Zwieten, P. A.

1989-01-01

Alpha adrenoceptors should be divided into various subtypes, comprising pre/postsynaptic and alpha 1/alpha 2-subpopulations, respectively. This classification implicates important functional differences between the various alpha-receptor subtypes, including certain differences in signal transduction

Preoperative Alpha-Fetoprotein Slope is Predictive of Hepatocellular Carcinoma Recurrence after Liver Transplantation

Directory of Open Access Journals (Sweden)

Kathy Han

2007-01-01

Full Text Available BACKGROUND: Liver transplantation (LT offers a possible cure for patients with hepatocellular carcinoma (HCC and cirrhosis. However, tumour progression while on the waiting list and tumour recurrence after LT are common. The prognostic significance of various pre- and postoperative variables were investigated in regard to tumour recurrence, with an emphasis on the slope of preoperative serum alpha-fetoprotein (AFP levels.

Determination of alpha particle detection efficiency of an imaging plate (IP) detector

International Nuclear Information System (INIS)

Rahman, N.M; Iida, Takao; Yamazawa, Hiromi; Moriizumi, Jun

2006-01-01

In order to determine the detection efficiency of the imaging plate (IP) detector, the true radioactivity of the alpha particles, which sampled in the collection media, should be known. The true radioactivity could be accurately predicted with the help of the reference alpha spectrometer measurement. The detection efficiency calculated for the IP was estimated with the theoretical curve and the experimental data. It is assumed that the air sample contained the decay products of both 222 Rn and 220 Rn series, the most significant sources of alpha particles. The present study estimated the detection efficiency of the IP as 39.3% with an uncertainty of 2.9 that is well enough to confirm the future use of the IP as a radiation detector. Experimental materials and methods are described. (S.Y.)

Metastable Structural Phases of Metals in Columns IVB to Vib, and Rows 4 TO 6 OF the Periodic Table

Science.gov (United States)

Nnolim, Neme; Tyson, Trevor

2002-03-01

Total energy calculations as a function of strain along the direction have been carried out for the bcc metals V, Nb, Ta, Cr, Mo and W, and the hcp metals Ti, Zr and Hf, all in the block of the periodic table defined by columns IVB to VIB, and rows 4 to 6. Since strain along the direction corresponds to variation of the c lattice constant with respect to the a lattice constant, the total energy per unit cell has being calculated as a function of the c/a ratio. The highly accurate FP-LAPW (Full Potential Linearized Augmented Plane Wave) band structure method in the DFT (Density Functional Theory) formalism has been used for the calculations. In all cases except for the hcp column IVB elements, Zr, Hf and Ti, a metastable state was predicted from the calculations. Electronic properties are computed for all structures and are correlated with electrical and mechanical properties of metastable phases that have been observed experimentally. Properties of metastable phases, which were predicted in this work but which as of yet have not been observed experimentally, have also been predicted. Special attention is paid to the phases of tantalum and calculated transport properties are used to show that the observed high resistivity of the beta phase of tantalum relative to the alpha bcc phase cannot be explained solely by simple tetragonal distortions of the bcc phase.

Generation and mid-IR measurement of a gas-phase to predict security parameters of aviation jet fuel.

Science.gov (United States)

Gómez-Carracedo, M P; Andrade, J M; Calviño, M A; Prada, D; Fernández, E; Muniategui, S

2003-07-27

The worldwide use of kerosene as aviation jet fuel makes its safety considerations of most importance not only for aircraft security but for the workers' health (chronic and/or acute exposure). As most kerosene risks come from its vapours, this work focuses on predicting seven characteristics (flash point, freezing point, % of aromatics and four distillation points) which assess its potential hazards. Two experimental devices were implemented in order to, first, generate a kerosene vapour phase and, then, to measure its mid-IR spectrum. All the working conditions required to generate the gas phase were optimised either in a univariate or a multivariate (SIMPLEX) approach. Next, multivariate prediction models were deployed using partial least squares regression and it was found that both the average prediction errors and precision parameters were satisfactory, almost always well below the reference figures.

Impact of ICRH on the measurement of fusion alphas by collective Thomson scattering in ITER

DEFF Research Database (Denmark)

Salewski, Mirko; Eriksson, L.-G.; Bindslev, Henrik

2009-01-01

Collective Thomson scattering (CTS) has been proposed for measuring the phase space distributions of confined fast ion populations in ITER plasmas. This study determines the impact of fast ions accelerated by ion cyclotron resonance heating (ICRH) on the ability of CTS to diagnose fusion alphas......, corresponding to an off-axis resonance. The sensitivities of the results to the He-3 concentration (0.1-4%) and the heating power (20-40 MW) are considered. Fusion born alphas dominate the total CTS signal for large Doppler shifts of the scattered radiation. The tritons generate a negligible fraction...... perpendicular velocities, it may be difficult to draw conclusions about the physics of alpha particles alone by CTS. With this exception, the CTS diagnostic can reveal the physics of the fusion alphas in ITER even under the presence of fast ions due to ICRH....

Alpha-in-air monitor for continuous monitoring based on alpha to beta ratio

International Nuclear Information System (INIS)

Somayaji, K.S.; Venkataramani, R.; Swaminathan, N.; Pushparaja

1997-01-01

Measurement of long-lived alpha activity collected on a filter paper in continuous air monitoring of ambient working environment is difficult due to interference from much larger concentrations of short-lived alpha emitting daughter products of 222 Rn and 220 Rn. However, the ratio between the natural alpha and beta activity is approximately constant and this constancy of the ratio is used to discriminate against short-lived natural radioactivity in continuous air monitoring. Detection system was specially designed for the purpose of simultaneous counting of alpha and beta activity deposited on the filter paper during continuous monitoring. The activity ratios were calculated and plotted against the monitoring duration up to about six hours. Monitoring was carried out in three facilities with different ventilation conditions. Presence of any long-lived alpha contamination on the filter paper results in increase in the alpha to beta ratio. Long-lived 239 Pu contamination of about 16 DAC.h could be detected after about 45 minutes of commencement of the sampling. The experimental results using prototype units have shown that the approach of using alpha to beta activity ratio method to detect long-lived alpha activity in the presence of short-lived natural activity is satisfactory. (author)

A study of etching model of alpha-recoil tracks in biotite

International Nuclear Information System (INIS)

Dong Jinquan; Yuan Wanming; Wang Shicheng; Fan Qicheng

2005-01-01

Like fission-track dating, alpha-recoil track (ART) dating is based on the accumulation of nuclear particles that the released from natural radioactivity and produce etchable tracks in solids. ARTs are formed during the alpha-decay of uranium and thorium as well as of their daughter nuclei. When emitting an alpha-particle, the heavy remaining nucleus recoils 30-40 nm, leaving behind a trail of radiation damage. Through etching the ART tracks become visible with the aid of an interference phase-contrast microscope. Under the presupposition that all tracks are preserved since the formation of a sample their total number is a measure of the sample's age. The research for etching model is to accurately determine ART volume density, i.e., the number of ARTs per unit volume. The volume density of many dots in many layers may be determined on a sample using this etching model, and as decreasing the error and increasing the accuracy. (authors)

Screening alpha-glucosidase and alpha-amylase inhibitors from natural compounds by molecular docking in silico.

Science.gov (United States)

Jhong, Chien-Hung; Riyaphan, Jirawat; Lin, Shih-Hung; Chia, Yi-Chen; Weng, Ching-Feng

2015-01-01

The alpha-glucosidase inhibitor is a common oral anti-diabetic drug used for controlling carbohydrates normally converted into simple sugars and absorbed by the intestines. However, some adverse clinical effects have been observed. The present study seeks an alternative drug that can regulate the hyperglycemia by down-regulating alpha-glucosidase and alpha-amylase activity by molecular docking approach to screen the hyperglycemia antagonist against alpha-glucosidase and alpha-amylase activities from the 47 natural compounds. The docking data showed that Curcumin, 16-hydroxy-cleroda-3,13-dine-16,15-olide (16-H), Docosanol, Tetracosanol, Antroquinonol, Berberine, Catechin, Quercetin, Actinodaphnine, and Rutin from 47 natural compounds had binding ability towards alpha-amylase and alpha-glucosidase as well. Curcumin had a better biding ability of alpha-amylase than the other natural compounds. Analyzed alpha-glucosidase activity reveals natural compound inhibitors (below 0.5 mM) are Curcumin, Actinodaphnine, 16-H, Quercetin, Berberine, and Catechin when compared to the commercial drug Acarbose (3 mM). A natural compound with alpha-amylase inhibitors (below 0.5 mM) includes Curcumin, Berberine, Docosanol, 16-H, Actinodaphnine/Tetracosanol, Catechin, and Quercetin when compared to Acarbose (1 mM). When taken together, the implication is that molecular docking is a fast and effective way to screen alpha-glucosidase and alpha-amylase inhibitors as lead compounds of natural sources isolated from medicinal plants. © 2015 International Union of Biochemistry and Molecular Biology.

Long-range alpha detector

International Nuclear Information System (INIS)

MacArthur, D.W.; McAtee, J.L.

1991-01-01

Historically, alpha-particle and alpha-contamination detectors have been limited by the very short range of alpha particles in air and by relatively poor sensitivity even if the particles are intercepted. Alpha detectors have had to be operated in a vacuum or in close proximity to the source if reasonable efficiency is desired. Alpha particles interact with the ambient air, producing ionization in the air at the rate of ∼30,000 ion pairs per mega-electron-volt of alpha energy. These charges can be transported over significant distances (several meters) in a moving current of air generated by a small fan. An ion chamber located in front of the fan measures the current carried by the moving ions. The long-range alpha detector (LRAD) offers several advantages over more traditional alpha detectors. First and foremost, it can operate efficiently even if the contamination is not easily accessible. Second, ions generated by contamination in crevices and other unmonitorable locations can be detected if the airflow penetrates those areas. Third, all of the contamination on a large surface will generate ions that can be detected in a single detector; hence, the detector's sensitivity to distributed sources is not limited by the size of the probe. Finally, a simple ion chamber can detect very small electric currents, making this technique potentially quite sensitive

Design of a preamplifier for an alpha particles spectrometer; Diseno de un preamplificador para un espectrometro de particulas alfa

Energy Technology Data Exchange (ETDEWEB)

Murillo O, R.; Hernandez D, V. M.; Chacon R, A.; Vega C, H. R., E-mail: fermineutron@yahoo.co [Universidad Autonoma de Zacatecas, Unidades Academicas de Estudios Nucleares e Ingenieria Electrica, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

2010-09-15

To detect radiation diverse detector types are used, when these are alpha particles proportional type detectors are used, semiconductor, of scintillation or traces. In this work the design results, the construction and the first tests of a spectrometer (preamplifier) are presented for alpha particles that was designed starting from a Pin type photodiode. The system was designed and simulated with a program for electronic circuits. With the results of the simulation phase was constructed the electronics that is coupled to a spectroscopic amplifier and a multichannel analyzer. The total of the system is evaluated analyzing its performance before a triple source of alphas and that they are produced by two smoke detectors of domestic use. Of the tests phase we find that the system allows to obtain in a multichannel, the pulses height spectrum, with which we calibrate the system. (Author)

The influence of phase transitions in phosphatidylethanolamine models on the activity of violaxanthin de-epoxidase.

Science.gov (United States)

Vieler, Astrid; Scheidt, Holger A; Schmidt, Peter; Montag, Cindy; Nowoisky, Janine F; Lohr, Martin; Wilhelm, Christian; Huster, Daniel; Goss, Reimund

2008-04-01

In the present study, the influence of the phospholipid phase state on the activity of the xanthophyll cycle enzyme violaxanthin de-epoxidase (VDE) was analyzed using different phosphatidylethanolamine species as model lipids. By using (31)P NMR spectroscopy, differential scanning calorimetry and temperature dependent enzyme assays, VDE activity could directly be related to the lipid structures the protein is associated with. Our results show that the gel (L beta) to liquid-crystalline (L alpha) phase transition in these single lipid component systems strongly enhances both the solubilization of the xanthophyll cycle pigment violaxanthin in the membrane and the activity of the VDE. This phase transition has a significantly stronger impact on VDE activity than the transition from the L alpha to the inverted hexagonal (HII) phase. Especially at higher temperatures we found increased VDE reaction rates in the presence of the L alpha phase compared to those in the presence of HII phase forming lipids. Our data furthermore imply that the HII phase is better suited to maintain high VDE activities at lower temperatures.

GABAergic modulation of visual gamma and alpha oscillations and its consequences for working memory performance.

Science.gov (United States)

Lozano-Soldevilla, Diego; ter Huurne, Niels; Cools, Roshan; Jensen, Ole

2014-12-15

Impressive in vitro research in rodents and computational modeling has uncovered the core mechanisms responsible for generating neuronal oscillations. In particular, GABAergic interneurons play a crucial role for synchronizing neural populations. Do these mechanistic principles apply to human oscillations associated with function? To address this, we recorded ongoing brain activity using magnetoencephalography (MEG) in healthy human subjects participating in a double-blind pharmacological study receiving placebo, 0.5 mg and 1.5 mg of lorazepam (LZP; a benzodiazepine upregulating GABAergic conductance). Participants performed a demanding visuospatial working memory (WM) task. We found that occipital gamma power associated with WM recognition increased with LZP dosage. Importantly, the frequency of the gamma activity decreased with dosage, as predicted by models derived from the rat hippocampus. A regionally specific gamma increase correlated with the drug-related performance decrease. Despite the system-wide pharmacological intervention, gamma power drug modulations were specific to visual cortex: sensorimotor gamma power and frequency during button presses remained unaffected. In contrast, occipital alpha power modulations during the delay interval decreased parametrically with drug dosage, predicting performance impairment. Consistent with alpha oscillations reflecting functional inhibition, LZP affected alpha power strongly in early visual regions not required for the task demonstrating a regional specific occipital impairment. GABAergic interneurons are strongly implicated in the generation of gamma and alpha oscillations in human occipital cortex where drug-induced power modulations predicted WM performance. Our findings bring us an important step closer to linking neuronal dynamics to behavior by embracing established animal models. Copyright © 2014 Elsevier Ltd. All rights reserved.

Neural network prediction of relativistic electrons at geosynchronous orbit during the storm recovery phase: effects of recurring substorms

Directory of Open Access Journals (Sweden)

M. Fukata

2002-07-01

Full Text Available During the recovery phase of geomagnetic storms, the flux of relativistic (>2 MeV electrons at geosynchronous orbits is enhanced. This enhancement reaches a level that can cause devastating damage to instruments on satellites. To predict these temporal variations, we have developed neural network models that predict the flux for the period 1–12 h ahead. The electron-flux data obtained during storms, from the Space Environment Monitor on board a Geostationary Meteorological Satellite, were used to construct the model. Various combinations of the input parameters AL, SAL, Dst and SDst were tested (where S denotes the summation from the time of the minimum Dst. It was found that the model, including SAL as one of the input parameters, can provide some measure of relativistic electron-flux prediction at geosynchronous orbit during the recovery phase. We suggest from this result that the relativistic electron-flux enhancement during the recovery phase is associated with recurring substorms after Dst minimum and their accumulation effect.Key words. Magnetospheric physics (energetic particles, trapped; magnetospheric configuration and dynamics; storms and substorms

Treatment of alpha bearing wastes

International Nuclear Information System (INIS)

1988-01-01

This report deals with the current state of the art of alpha waste treatment, which is an integral part of the overall nuclear waste management system. The International Atomic Energy Agency (IAEA) defines alpha bearing waste as 'waste containing one or more alpha emitting radionuclides, usually actinides, in quantities above acceptable limits'. The limits are established by national regulatory bodies. The limits above which wastes are considered as alpha contaminated refer to the concentrations of alpha emitters that need special consideration for occupational exposures and/or potential safety, health, or environmental impact during one or more steps from generation through disposal. Owing to the widespread use of waste segregation by source - that is, based upon the 'suspect origin' of the material - significant volumes of waste are being handled as alpha contaminated which, in fact, do not require such consideration by reason of risk or environmental concern. The quantification of de minimis concepts by national regulatory bodies could largely contribute to the safe reduction of waste volumes and associated costs. Other factors which could significantly contribute to the reduction of alpha waste arisings are an increased application of assaying and sorting, instrumentation and the use of feedback mechanisms to control or modify the processes which generate these wastes. Alpha bearing wastes are generated during fabrication and reprocessing of nuclear fuels, decommissioning of alpha contaminated facilities, and other activities. Most alpha wastes are contact handled, but a small portion may require shielding or remote handling because of high levels of neutron (n), beta (β), or gamma (γ) emissions associated with the waste material. This report describes the sources and characteristics of alpha wastes and strategies for alpha waste management. General descriptions of treatment processes for solid and liquid alpha wastes are included. 71 refs, 14 figs, 9 tabs

Using different drift gases to change separation factors (alpha) in ion mobility spectrometry

Science.gov (United States)

Asbury; Hill

2000-02-01

The use of different drift gases to alter separation factors (alpha) in ion mobility spectrometry has been demonstrated. The mobility of a series of low molecular weight compounds and three small peptides was determined in four different drift gases. The drift gases chosen were helium, argon, nitrogen, and carbon dioxide. These drift gases provide a range of polarizabilities and molecular weights. In all instances, the compounds showed the greatest mobility in helium and the lowest mobility in carbon dioxide; however the percentage change of mobility for each compound was different, effectively changing the alpha value. The alpha value changes were primarily due to differences in drift gas polarizability but were also influenced by the mass of the drift gas. In addition, gas-phase ion radii were calculated in each of the different drift gases. These radii were then plotted against drift gas polarizability producing linear plots with r2 values greater than 0.99. The intercept of these plots provides the gas-phase radius of an ion in a nonpolarizing environment, whereas the slope is indicative of the magnitude of the ion's mobility change related to polarizability. It therefore, should be possible to separate any two compounds that have different slopes with the appropriate drift gas.

New ALPHA-2 magnet

CERN Multimedia

Anaïs Schaeffer

2012-01-01

On 21 June, members of the ALPHA collaboration celebrated the handover of the first solenoid designed for the ALPHA-2 experiment. The magnet has since been successfully installed and is working well.   Khalid Mansoor, Sumera Yamin and Jeffrey Hangst in front of the new ALPHA-2 solenoid. “This was the first of three identical solenoids that will be installed between now and September, as the rest of the ALPHA-2 device is installed and commissioned,” explains ALPHA spokesperson Jeffrey Hangst. “These magnets are designed to allow us to transfer particles - antiprotons, electrons and positrons - between various parts of the new ALPHA-2 device by controlling the transverse size of the particle bunch that is being transferred.” Sumera Yamin and Khalid Mansoor, two Pakistani scientists from the National Centre for Physics in Islamabad, came to CERN in February specifically to design and manufacture these magnets. “We had the chance to work on act...

ALPHA-2: the sequel

CERN Multimedia

Katarina Anthony

2012-01-01

While many experiments are methodically planning for intense works over the long shutdown, there is one experiment that is already working at full steam: ALPHA-2. Its final components arrived last month and will completely replace the previous ALPHA set-up. Unlike its predecessor, this next generation experiment has been specifically designed to measure the properties of antimatter.   The ALPHA team lower the new superconducting solenoid magnet into place. The ALPHA collaboration is working at full speed to complete the ALPHA-2 set-up for mid-November – this will give them a few weeks of running before the AD shutdown on 17 December. “We really want to get some experience with this device this year so that, if we need to make any changes, we will have time during the long shutdown in which to make them,” says Jeffrey Hangst, ALPHA spokesperson. “Rather than starting the 2014 run in the commissioning stage, we will be up and running from the get go.&...

Technical Basis for the Use of Alpha Absorption Corrections on RCF Gross Alpha Data