Reconstruction of neutrino induced NC-1π{sup 0} using the T2K-ND280 tracker

DOE Office of Scientific and Technical Information (OSTI.GOV)

O’Keeffe, H. M.; Vacheret, A.; Barr, G. D.

2015-05-15

Single π{sup 0} production is the one of the most important backgrounds in the υ{sub e} appearance measurement in T2K. Large uncertainties in this production make it difficult to predict. Measurement at the near detector (ND280) is required both to constrain the background prediction at the far detector (Super-K) and also at the near detector to improve knowledge of beam υ{sub e} contamination. We present an analysis based on Monte Carlo simulation of neutral current (NC) single π{sup 0} in the tracker region. NC-1π{sup 0} events are selected using a specific two-gamma signature in the tracker region. One decay gammamore » is reconstructed by selecting an e+/e− pair starting in the Fine-Grained target Detector (FGD) and extending into the TPC, where the leptons can be identified and their momentum measured accurately. The second gamma is then selected in-time in the Calorimeter modules surrounding the tracker. Selections cuts, efficiency and purity of the selection are presented and projection of the expected number of single π{sup 0} candidates for 3 × 10{sup 20} protons on target (PoT) exposure is made.« less

Anisotropic H c 2 , thermodynamic and transport measurements, and pressure dependence of T c in K 2 Cr 3 As 3 single crystals

DOE PAGES

Kong, Tai; Bud'ko, Sergey L.; Canfield, Paul C.

2015-01-30

We present a detailed study of single crystalline K 2Cr 3As 3 and analyze its thermodynamic and transport properties, anisotropic H c2(T), and initial pressure dependence of T c. In zero field, the temperature-dependent resistivity is metallic. Deviation from a linear temperature dependence is evident below 100 K and a T 3 dependence is roughly followed from just above T c (~10K) to ~40K. Anisotropic H c2(T) data were measured up to 140 kOe with field applied along and perpendicular to the rodlike crystals. For the applied field perpendicular to the rod, H c2(T) is linear with a slope ~–70more » kOe/K. For field applied along the rod, the slope is about –120 kOe/K below 70 kOe. Above 70 kOe, the magnitude of the slope decreases to ~–70 kOe/K. The electronic specific heat coefficient γ, just above T c, is 73 mJ/mol K 2; the Debye temperature Θ D is 220 K. As a result, the specific heat jump at the superconducting transition ΔC~2.2γT c. Finally, for hydrostatic pressures up to ~7 kbar, T c decreases under pressure linearly at a rate of –0.034K/kbar.« less

Monitoring oil displacement processes with k-t accelerated spin echo SPI.

PubMed

Li, Ming; Xiao, Dan; Romero-Zerón, Laura; Balcom, Bruce J

2016-03-01

Magnetic resonance imaging (MRI) is a robust tool to monitor oil displacement processes in porous media. Conventional MRI measurement times can be lengthy, which hinders monitoring time-dependent displacements. Knowledge of the oil and water microscopic distribution is important because their pore scale behavior reflects the oil trapping mechanisms. The oil and water pore scale distribution is reflected in the magnetic resonance T2 signal lifetime distribution. In this work, a pure phase-encoding MRI technique, spin echo SPI (SE-SPI), was employed to monitor oil displacement during water flooding and polymer flooding. A k-t acceleration method, with low-rank matrix completion, was employed to improve the temporal resolution of the SE-SPI MRI measurements. Comparison to conventional SE-SPI T2 mapping measurements revealed that the k-t accelerated measurement was more sensitive and provided higher-quality results. It was demonstrated that the k-t acceleration decreased the average measurement time from 66.7 to 20.3 min in this work. A perfluorinated oil, containing no (1) H, and H2 O brine were employed to distinguish oil and water phases in model flooding experiments. High-quality 1D water saturation profiles were acquired from the k-t accelerated SE-SPI measurements. Spatially and temporally resolved T2 distributions were extracted from the profile data. The shift in the (1) H T2 distribution of water in the pore space to longer lifetimes during water flooding and polymer flooding is consistent with increased water content in the pore space. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Time-resolved 3D pulmonary perfusion MRI: comparison of different k-space acquisition strategies at 1.5 and 3 T.

PubMed

Attenberger, Ulrike I; Ingrisch, Michael; Dietrich, Olaf; Herrmann, Karin; Nikolaou, Konstantin; Reiser, Maximilian F; Schönberg, Stefan O; Fink, Christian

2009-09-01

Time-resolved pulmonary perfusion MRI requires both high temporal and spatial resolution, which can be achieved by using several nonconventional k-space acquisition techniques. The aim of this study is to compare the image quality of time-resolved 3D pulmonary perfusion MRI with different k-space acquisition techniques in healthy volunteers at 1.5 and 3 T. Ten healthy volunteers underwent contrast-enhanced time-resolved 3D pulmonary MRI on 1.5 and 3 T using the following k-space acquisition techniques: (a) generalized autocalibrating partial parallel acquisition (GRAPPA) with an internal acquisition of reference lines (IRS), (b) GRAPPA with a single "external" acquisition of reference lines (ERS) before the measurement, and (c) a combination of GRAPPA with an internal acquisition of reference lines and view sharing (VS). The spatial resolution was kept constant at both field strengths to exclusively evaluate the influences of the temporal resolution achieved with the different k-space sampling techniques on image quality. The temporal resolutions were 2.11 seconds IRS, 1.31 seconds ERS, and 1.07 VS at 1.5 T and 2.04 seconds IRS, 1.30 seconds ERS, and 1.19 seconds VS at 3 T.Image quality was rated by 2 independent radiologists with regard to signal intensity, perfusion homogeneity, artifacts (eg, wrap around, noise), and visualization of pulmonary vessels using a 3 point scale (1 = nondiagnostic, 2 = moderate, 3 = good). Furthermore, the signal-to-noise ratio in the lungs was assessed. At 1.5 T the lowest image quality (sum score: 154) was observed for the ERS technique and the highest quality for the VS technique (sum score: 201). In contrast, at 3 T images acquired with VS were hampered by strong artifacts and image quality was rated significantly inferior (sum score: 137) compared with IRS (sum score: 180) and ERS (sum score: 174). Comparing 1.5 and 3 T, in particular the overall rating of the IRS technique (sum score: 180) was very similar at both field

The T2K ND280 off-axis pi-zero detector

NASA Astrophysics Data System (ADS)

Assylbekov, S.; Barr, G.; Berger, B. E.; Berns, H.; Beznosko, D.; Bodek, A.; Bradford, R.; Buchanan, N.; Budd, H.; Caffari, Y.; Connolly, K.; Danko, I.; Das, R.; Davis, S.; Day, M.; Dytman, S.; Dziomba, M.; Flight, R.; Forbush, D.; Gilje, K.; Hansen, D.; Hignight, J.; Imber, J.; Johnson, R. A.; Jung, C. K.; Kravtsov, V.; Le, P. T.; Lopez, G. D.; Malafis, C. J.; Manly, S.; Marino, A. D.; McFarland, K. S.; McGrew, C.; Metelko, C.; Nagashima, G.; Naples, D.; Nicholls, T. C.; Nielsen, B.; Paolone, V.; Paul, P.; Pearce, G. F.; Qian, W.; Ramos, K.; Reinherz-Aronis, E.; Rodrigues, P. A.; Ruterbories, D.; Schmidt, J.; Schwehr, J.; Siyad, M.; Steffens, J.; Tadepalli, A. S.; Taylor, I. J.; Thorpe, M.; Toki, W.; Vanek, C.; Warner, D.; Weber, A.; Wilkes, R. J.; Wilson, R. J.; Yanagisawa, C.; Yuan, T.

2012-09-01

The pi-zero detector (PØD) is one of the subdetectors that makes up the off-axis near detector for the Tokai-to-Kamioka (T2K) long baseline neutrino experiment. The primary goal for the PØD is to measure the relevant cross-sections for neutrino interactions that generate π0's, especially the cross-section for neutral current π0 interactions, which are one of the dominant sources of background to the νμ→νe appearance signal in T2K. The PØD is composed of layers of plastic scintillator alternating with water bags and brass sheets or lead sheets and is one of the first detectors to use Multi-Pixel Photon Counters (MPPCs) on a large scale.

Gas phase kinetics of the OH + CH3CH2OH reaction at temperatures of the interstellar medium (T = 21-107 K).

PubMed

Ocaña, A J; Blázquez, S; Ballesteros, B; Canosa, A; Antiñolo, M; Albaladejo, J; Jiménez, E

2018-02-21

Ethanol, CH 3 CH 2 OH, has been unveiled in the interstellar medium (ISM) by radioastronomy and it is thought to be released into the gas phase after the warm-up phase of the grain surface, where it is formed. Once in the gas phase, it can be destroyed by different reactions with atomic and radical species, such as hydroxyl (OH) radicals. The knowledge of the rate coefficients of all these processes at temperatures of the ISM is essential in the accurate interpretation of the observed abundances. In this work, we have determined the rate coefficient for the reaction of OH with CH 3 CH 2 OH (k(T)) between 21 and 107 K by employing the pulsed and continuous CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme, which means Reaction Kinetics in a Uniform Supersonic Flow) technique. The pulsed laser photolysis technique was used for generating OH radicals, whose time evolution was monitored by laser induced fluorescence. An increase of approximately 4 times was observed for k(21 K) with respect to k(107 K). With respect to k(300 K), the OH-reactivity at 21 K is enhanced by two orders of magnitude. The obtained T-expression in the investigated temperature range is k(T) = (2.1 ± 0.5) × 10 -11 (T/300 K) -(0.71±0.10) cm 3 molecule -1 s -1 . In addition, the pressure dependence of k(T) has been investigated at several temperatures between 21 K and 90 K. No pressure dependence of k(T) was observed in the investigated ranges. This may imply that this reaction is purely bimolecular or that the high-pressure limit is reached at the lowest total pressure experimentally accessible in our system. From our results, k(T) at usual IS temperatures (∼10-100 K) is confirmed to be very fast. Typical rate coefficients can be considered to range within about 4 × 10 -11 cm 3 molecule -1 s -1 at 100 K and around 1 × 10 -10 cm 3 molecule -1 s -1 at 20 K. The extrapolation of k at the lowest temperatures of the dense molecular clouds of ISM is also discussed in this paper.

Advanced Hard Real-Time Operating System, The Maruti Project. Part 1.

DTIC Science & Technology

1997-01-01

REAL - TIME OPERATING SYSTEM , THE MARUTI PROJECT Part 1 of 2 Ashok K. Agrawala Satish K. Tripathi Department of Computer Science University of Maryland...Hard Real - Time Operating System , The Maruti Project DASG-60-92-C-0055 5b. Program Element # 62301E 6. Author(s) 5c. Project # DRPB Ashok K. Agrawala...SdSA94), a real - time operating system developed at the I3nversity of Maryland, and conducted extensive experiments under various task

Gas phase kinetics of the OH + CH3CH2OH reaction at temperatures of the interstellar medium (T = 21-10^7 K)

NASA Astrophysics Data System (ADS)

Ocaña, A. J.; Blázquez, S.; Ballesteros, B.; Canosa, A.; Antiñolo, M.; Albaladejoab, J.; Jiménez, E.

2018-02-01

Ethanol, CH3CH2OH, has been unveiled in the interstellar medium (ISM) by radioastronomy and it is thought to be released into the gas phase after the warm-up phase of the grain surface, where it is formed. Once in the gas phase, it can be destroyed by different reactions with atomic and radical species, such as hydroxyl (OH) radicals. The knowledge of the rate coefficients of all these processes at temperatures of the ISM is essential in the accurate interpretation of the observed abundances. In this work, we have determined the rate coefficient for the reaction of OH with CH3CH2OH (k(T)) between 21 and 10^7 K by employing the pulsed and continuous CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme, which means Reaction Kinetics in a Uniform Supersonic Flow) technique. The pulsed laser photolysis technique was used for generating OH radicals, whose time evolution was monitored by laser induced fluorescence. An increase of approximately 4 times was observed for k(21 K) with respect to k(10^7 K). With respect to k(300 K), the OH-reactivity at 21 K is enhanced by two orders of magnitude. The obtained T-expression in the investigated temperature range is k(T) = (2.1 ± 0.5) × 10^-11 (T/300 K)-(0.71±0.10) cm^3 molecule^-1 s^-1. In addition, the pressure dependence of k(T) has been investigated at several temperatures between 21 K and 90 K. No pressure dependence of k(T) was observed in the investigated ranges. This may imply that this reaction is purely bimolecular or that the high-pressure limit is reached at the lowest total pressure experimentally accessible in our system. From our results, k(T) at usual IS temperatures (˜10-100 K) is confirmed to be very fast. Typical rate coefficients can be considered to range within about 4 × 10^-11 cm^3 molecule^-1 s^-1 at 100 K and around 1 × 10^-10 cm^3 molecule^-1 s^-1 at 20 K. The extrapolation of k at the lowest temperatures of the dense molecular clouds of ISM is also discussed in this paper.

Fish-T1K (Transcriptomes of 1,000 Fishes) Project: large-scale transcriptome data for fish evolution studies.

PubMed

Sun, Ying; Huang, Yu; Li, Xiaofeng; Baldwin, Carole C; Zhou, Zhuocheng; Yan, Zhixiang; Crandall, Keith A; Zhang, Yong; Zhao, Xiaomeng; Wang, Min; Wong, Alex; Fang, Chao; Zhang, Xinhui; Huang, Hai; Lopez, Jose V; Kilfoyle, Kirk; Zhang, Yong; Ortí, Guillermo; Venkatesh, Byrappa; Shi, Qiong

2016-01-01

Ray-finned fishes (Actinopterygii) represent more than 50 % of extant vertebrates and are of great evolutionary, ecologic and economic significance, but they are relatively underrepresented in 'omics studies. Increased availability of transcriptome data for these species will allow researchers to better understand changes in gene expression, and to carry out functional analyses. An international project known as the "Transcriptomes of 1,000 Fishes" (Fish-T1K) project has been established to generate RNA-seq transcriptome sequences for 1,000 diverse species of ray-finned fishes. The first phase of this project has produced transcriptomes from more than 180 ray-finned fishes, representing 142 species and covering 51 orders and 109 families. Here we provide an overview of the goals of this project and the work done so far.

NMR characterization of sulphur substitution effects in the K xFe 2-ySe 2-xS z high-T c superconductor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Torchetti, D. A.; Imai, T.; Lei, H. C.

2012-04-17

We present a 77Se NMR study of the effect of S substitution in the high-T c superconductor K xFe 2-ySe 2-zS z in a temperature range up to 250 K. We examine two S concentrations, with z=0.8 (T c~ 26 K) and z=1.6 (nonsuperconducting). The samples containing sulphur exhibit broader NMR line shapes than the K xFe 2Se 2 sample due to local disorder in the Se environment. Our Knight shift 77K data indicate that in all samples, uniform spin susceptibility decreases with temperature, and that the magnitude of the Knight shift itself decreases with increased S concentration. In addition,more » S substitution progressively suppresses low-frequency spin fluctuations. None of the samples exhibit an enhancement of low-frequency antiferromagnetic spin fluctuations near T c in 1/T 1T, as seen in FeSe.« less

High-k shallow traps observed by charge pumping with varying discharging times

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, Szu-Han; Chen, Ching-En; Tseng, Tseung-Yuen

2013-11-07

In this paper, we investigate the influence of falling time and base level time on high-k bulk shallow traps measured by charge pumping technique in n-channel metal-oxide-semiconductor field-effect transistors with HfO{sub 2}/metal gate stacks. N{sub T}-V{sub high} {sub level} characteristic curves with different duty ratios indicate that the electron detrapping time dominates the value of N{sub T} for extra contribution of I{sub cp} traps. N{sub T} is the number of traps, and I{sub cp} is charge pumping current. By fitting discharge formula at different temperatures, the results show that extra contribution of I{sub cp} traps at high voltage are inmore » fact high-k bulk shallow traps. This is also verified through a comparison of different interlayer thicknesses and different Ti{sub x}N{sub 1−x} metal gate concentrations. Next, N{sub T}-V{sub high} {sub level} characteristic curves with different falling times (t{sub falling} {sub time}) and base level times (t{sub base} {sub level}) show that extra contribution of I{sub cp} traps decrease with an increase in t{sub falling} {sub time}. By fitting discharge formula for different t{sub falling} {sub time}, the results show that electrons trapped in high-k bulk shallow traps first discharge to the channel and then to source and drain during t{sub falling} {sub time}. This current cannot be measured by the charge pumping technique. Subsequent measurements of N{sub T} by charge pumping technique at t{sub base} {sub level} reveal a remainder of electrons trapped in high-k bulk shallow traps.« less

Prediction of transits of Solar system objects in Kepler/K2 images: an extension of the Virtual Observatory service SkyBoT

NASA Astrophysics Data System (ADS)

Berthier, J.; Carry, B.; Vachier, F.; Eggl, S.; Santerne, A.

2016-05-01

All the fields of the extended space mission Kepler/K2 are located within the ecliptic. Many Solar system objects thus cross the K2 stellar masks on a regular basis. We aim at providing to the entire community a simple tool to search and identify Solar system objects serendipitously observed by Kepler. The sky body tracker (SkyBoT) service hosted at Institut de mécanique céleste et de calcul des éphémérides provides a Virtual Observatory compliant cone search that lists all Solar system objects present within a field of view at a given epoch. To generate such a list in a timely manner, ephemerides are pre-computed, updated weekly, and stored in a relational data base to ensure a fast access. The SkyBoT web service can now be used with Kepler. Solar system objects within a small (few arcminutes) field of view are identified and listed in less than 10 s. Generating object data for the entire K2 field of view (14°) takes about a minute. This extension of the SkyBoT service opens new possibilities with respect to mining K2 data for Solar system science, as well as removing Solar system objects from stellar photometric time series.

Phase diagrams for the system water/butyric acid/propylene carbonate at T = 293.2-313.2 K and p = 101.3 kPa

NASA Astrophysics Data System (ADS)

Shekarsaraee, Sina; Nahzomi, Hossein Taherpour; Nasiri-Touli, Elham

2017-11-01

Phase diagrams for the system water/butyric acid/propylene carbonate were plotted at T = 293.2, 303.2, 313.2 K and p = 101.3 kPa. Acidimetric titration and refractive index methods were used to determine tie-line data. Solubility data revealed that the studied system exhibits type-1 behavior of liquid-liquid equilibrium. The experimental data were regressed and acceptably correlated using the UNIQUAC and NRTL models. As a result, propylene carbonate is a suitable separating agent for aqueous mixture of butyric acid.

The PAGES 2k Network, Phase 3: Themes and Call for Participation

NASA Astrophysics Data System (ADS)

von Gunten, L.; Mcgregor, H. V.; Martrat, B.; St George, S.; Neukom, R.; Bothe, O.; Linderholm, H. W.; Phipps, S. J.; Abram, N.

2017-12-01

The past 2000 years (the "2k" interval) provides critical context for understanding recent anthropogenic forcing of the climate and provides baseline information about the characteristics of natural climate variability. It also presents opportunities to improve the interpretation of proxy observations and to evaluate the climate models used to make future projections. Phases 1 and 2 of the PAGES 2k Network focussed on building regional and global surface temperature reconstructions for terrestrial regions and the oceans, and comparing these with model simulations to identify mechanisms of climate variation on interannual to bicentennial time scales. Phase 3 was launched in May 2017 and aims to address major questions around past hydroclimate, climate processes and proxy uncertainties. Its scientific themes are: Theme 1: "Climate Variability, Modes and Mechanisms"Further understand the mechanisms driving regional climate variability and change on interannual to centennial time scales; Theme 2: "Methods and Uncertainties"Reduce uncertainties in the interpretation of observations imprinted in paleoclimatic archives by environmental sensors; Theme 3: "Proxy and Model Understanding"Identify and analyse the extent of agreement between reconstructions and climate model simulations. Research is organized as a linked network of well-defined projects, identified and led by 2k community members. The 2k projects focus on specific scientific questions aligned with Phase 3 themes, rather than being defined along regional boundaries. New 2k projects can be proposed at any time at http://www.pastglobalchanges.org/ini/wg/2k-network/projects An enduring element of PAGES 2k is a culture of collegiality, transparency, and reciprocity. Phase 3 seeks to stimulate community based projects and facilitate collaboration between researchers from different regions and career stages, drawing on the breadth and depth of the global PAGES 2k community. All PAGES 2k projects also promote best

Chemical and Electrochemical Asymmetric Dihydroxylation of Olefins in I(2)-K(2)CO(3)-K(2)OsO(2)(OH)(4) and I(2)-K(3)PO(4)/K(2)HPO(4)-K(2)OsO(2)(OH)(4) Systems with Sharpless' Ligand.

PubMed

Torii, Sigeru; Liu, Ping; Bhuvaneswari, Narayanaswamy; Amatore, Christian; Jutand, Anny

1996-05-03

Iodine-assisted chemical and electrochemical asymmetric dihydroxylation of various olefins in I(2)-K(2)CO(3)-K(2)OsO(2)(OH)(4) and I(2)-K(3)PO(4)/K(2)HPO(4)-K(2)OsO(2)(OH)(4) systems with Sharpless' ligand provided the optically active glycols in excellent isolated yields and high enantiomeric excesses. Iodine (I(2)) was used stoichiometrically for the chemical dihydroxylation, and good results were obtained with nonconjugated olefins in contrast to the case of potassium ferricyanide as a co-oxidant. The potentiality of I(2) as a co-oxidant under stoichiometric conditions has been proven to be effective as an oxidizing mediator in electrolysis systems. Iodine-assisted asymmetric electro-dihydroxylation of olefins in either a t-BuOH/H(2)O(1/1)-K(2)CO(3)/(DHQD)(2)PHAL-(Pt) or t-BuOH/H(2)O(1/1)-K(3)PO(4)/K(2)HPO(4)/(DHQD)(2)PHAL-(Pt) system in the presence of potassium osmate in an undivided cell was investigated in detail. Irrespective of the substitution pattern, all the olefins afforded the diols in high yields and excellent enantiomeric excesses. A plausible mechanism is discussed on the basis of cyclic voltammograms as well as experimental observations.

The effect of Liuwei Dihuang decoction on PI3K/Akt signaling pathway in liver of type 2 diabetes mellitus (T2DM) rats with insulin resistance.

PubMed

Dai, Bing; Wu, Qinxuan; Zeng, Chengxi; Zhang, Jiani; Cao, Luting; Xiao, Zizeng; Yang, Menglin

2016-11-04

Liuwei Dihaung decoction (LWDHT) is a well-known classic traditional Chinese medicine formula, consists of six herbs including Rehmannia glutinosa Libosch.(family: Scrophulariaceae), Cornus officinalis Sieb.(family: Cornaceae), Dioscorea opposite Thunb.(family: Dioscoreaceae), Alisma orientale(G. Samuelsson) Juz (family: Alismataceae), Poria cocos (Schw.) Wolf (family: Polyporaceae) and Paeonia suffruticosa Andrews (family: Paeoniaceae). It has been used in the treatment of many types of diseases with signs of deficiency of Yin in the kidneys in China clinically. This study is aimed at investigating the effect of Liuwei dihuang decoction on PI3K/Akt signaling pathway in liver of T2DM rats with insulin resistance. T2DM model was induced in male Sprague-Dawley (SD) rats by high sugar and high fat diets combined with small dose of streptozocin (STZ) injection. The successful T2DM rats were randomly allocated three group--vehicle group, positive control group and Liuwei Dihuang decoction group. After 12-weeks treatment with distilled water, rosiglitazone and LWDHT by intragastric administration respectively, the rats were put to death in batches. The variance of fasting blood glucose (FBG) and fasting insulin (FINS) in serum were determined, the pathological changes of each rats' liver were observed by hematoxylin-eosin (HE) staining, the expression of insulin receptor substrate 2(IRS2), phosphatidylinositol 3-kinase (PI3K) and protein kinas B (Akt) involving the canonical PI3K/Akt signaling pathway were detected by Real-time fluorescent quantitative PCR (RT-PCR), and the expression level of IRS2, PI3K, Akt protein and phosphorylated IRS2, PI3K, Akt protein were evaluated by Western Blot. All the data were analyzed by SPSS 17.0. Four weeks of treatment with LWDHT could significantly decrease the level of FBG and FINS in serum, improve the cellular morphology of liver, kidney, pancreas tissue, and the expression of IRS2, PI3K, Akt mRNA and phosphorylated IRS2, PI3K, Akt

K+-selective nanospheres: maximising response range and minimising response time.

PubMed

Ruedas-Rama, Maria Jose; Hall, Elizabeth A H

2006-12-01

Cross-linked K(+) ion-selective copolymer nanospheres have been prepared by free-radical photo-initiated polymerization of n-butyl acrylate (nBA) with hexanedioldiacrylate (HDDA). Nanospheres (<200 nm) containing H(+)-chromoionophore (ETH 5294) and lipophilic salt (KTClPB) for H(+)-sensors, or ETH 5294, a K(+)-selective ionophore (valinomycin) and anionic sites for K(+)-sensors were compared, and the effect of varying the normalised concentrations for beta (R(T)(-)/L(T)) and gamma (C(m)(T)/L(T)) was studied. Experimental data were fitted to theoretical curves for the dynamic response range, based on the effect of changes in the concentration of these lipophilic sensing components incorporated into the spheres, and conditions identified for maximising the response range. A complex valinomycin-K(+) formation constant, log K(IL) = 13.13 +/- 2.22, was obtained in the nBA matrix, and from the calibration curves the apparent acid-dissociation equilibrium constant (pK(a) = 12.92 +/- 0.03) was extracted for the H(+)-sensing system, and the equilibrium exchange constant (pK(exch) = 6.16 +/- 0.03, at pH 7) calculated for the K(+)-sensing nanospheres. A basis for establishing optimum performance was identified, whereby response range and response time were balanced with maximum fluorescence yield. Parameters for achieving nanospheres with a response time <5 minutes, covering 2-3 orders of magnitude change in activity were identified, demanding nanospheres with radius <300 nm and beta(crit) approximately 0.6. An RSD(%) approximately 3% was obtained in a study of the reproducibility of the response of the proposed nanospheres, and selectivity was also evaluated for a K(+)-selective nanosensor using several cations as interfering agents. In most cases, the fluorescent emission spectra showed no response to the cations tested, confirming the selectivity of nanospheres to potassium ion. The nanosensors were satisfactorily applied to the determination of K(+) in samples mimicking

Experimental investigation of a general real-time 3D target localization method using sequential kV imaging combined with respiratory monitoring.

PubMed

Cho, Byungchul; Poulsen, Per; Ruan, Dan; Sawant, Amit; Keall, Paul J

2012-11-21

The goal of this work was to experimentally quantify the geometric accuracy of a novel real-time 3D target localization method using sequential kV imaging combined with respiratory monitoring for clinically realistic arc and static field treatment delivery and target motion conditions. A general method for real-time target localization using kV imaging and respiratory monitoring was developed. Each dimension of internal target motion T(x, y, z; t) was estimated from the external respiratory signal R(t) through the correlation between R(t(i)) and the projected marker positions p(x(p), y(p); t(i)) on kV images by a state-augmented linear model: T(x, y, z; t) = aR(t) + bR(t - τ) + c. The model parameters, a, b, c, were determined by minimizing the squared fitting error ∑‖p(x(p), y(p); t(i)) - P(θ(i)) · (aR(t(i)) + bR(t(i) - τ) + c)‖(2) with the projection operator P(θ(i)). The model parameters were first initialized based on acquired kV arc images prior to MV beam delivery. This method was implemented on a trilogy linear accelerator consisting of an OBI x-ray imager (operating at 1 Hz) and real-time position monitoring (RPM) system (30 Hz). Arc and static field plans were delivered to a moving phantom programmed with measured lung tumour motion from ten patients. During delivery, the localization method determined the target position and the beam was adjusted in real time via dynamic multileaf collimator (DMLC) adaptation. The beam-target alignment error was quantified by segmenting the beam aperture and a phantom-embedded fiducial marker on MV images and analysing their relative position. With the localization method, the root-mean-squared errors of the ten lung tumour traces ranged from 0.7-1.3 mm and 0.8-1.4 mm during the single arc and five-field static beam delivery, respectively. Without the localization method, these errors ranged from 3.1-7.3 mm. In summary, a general method for real-time target localization using kV imaging and respiratory

Residual oxygen time model for oxygen partial pressure near 130 kPa (1.3 atm).

PubMed

Shykoff, Barbara E

2015-01-01

A two-part residual oxygen time model predicts the probability of detectible pulmonary oxygen toxicity P(P[O2tox]) after dives with oxygen partial pressure (PO2) approximately 130 kPa, and provides a tool to plan dive series with selected risk of P[O2tox]. Data suggest that pulmonary oxygen injury at this PO2 is additive between dives. Recovery begins after a delay and continues during any following dive. A logistic relation expresses P(P[O2tox]) as a function of dive duration (T(dur)) [hours]: P(P[O2tox]) = 100/[1+exp (3.586-0.49 x T(dur))] This expression maps T(dur) to P(P[O2tox]) or, in the linear mid-portion of the curve, P(P[O2tox]) usefully to T(dur). For multiple dives or during recovery, it maps to an equivalent dive duration, T(eq). T(eq) was found after second dives of duration T(dur 2). Residual time from the first dive t(r) = T(eq) - T(dur2). With known t(r), t and T(dur) a recovery model was fitted. t(r) = T(dur) x exp [-k x((t-5)/T(dur)2], where t = t - 5 hours, k = 0.149 for resting, and 0.047 for exercising divers, and t represents time after surfacing. The fits were assessed for 1,352 man-dives. Standard deviations of the residuals were 8.5% and 18.3% probability for resting or exercise dives, respectively.

Modeling neutrino-induced charged pion production on water at T2K kinematics

NASA Astrophysics Data System (ADS)

Nikolakopoulos, A.; González-Jiménez, R.; Niewczas, K.; Sobczyk, J.; Jachowicz, N.

2018-05-01

Pion production is a significant component of the signal in accelerator-based neutrino experiments. Over the last years, the MiniBooNE, T2K, and MINERvA collaborations have reported a substantial amount of data on (anti)neutrino-induced pion production on the nucleus. However, a comprehensive and consistent description of the whole data set is still missing. We aim at improving the current understanding of neutrino-induced pion production on the nucleus. To this end, the comparison of experimental data with theoretical predictions, preferably based on microscopic models, is essential to disentangle the different reaction mechanisms involved in the process. To describe single-pion production, we use a hybrid model that combines low- and a high-energy approaches. The low-energy model contains resonances and background terms. At high invariant masses, a high-energy model based on a Regge approach is employed. The model is implemented in the nucleus using the relativistic plane wave impulse approximation (RPWIA). We present a comparison of the hybrid-RPWIA and low-energy model with the recent neutrino-induced charged-current 1 π+ -production cross section on water reported by T2K. In order to judge the impact of final-state interactions (FSI), we confront our results with those of the nuwro Monte Carlo generator. The hybrid-RPWIA model and nuwro results compare favorably to the data, albeit that FSI are not included in the former. The need of a high-energy model at T2K kinematics is made clear. These results complement our previous work [Phys. Rev. D 97, 013004 (2018), 10.1103/PhysRevD.97.013004], in which we compared the models to the MINERvA and MiniBooNE 1 π+ data. The hybrid-RPWIA model tends to overpredict both the T2K and MINERvA data in kinematic regions where the largest suppression due to FSI is expected and agrees remarkably well with the data in other kinematic regions. On the contrary, the MiniBooNE data are underpredicted over the whole kinematic range.

Comparison of T1 and T2 metabolite relaxation times in glioma and normal brain at 3 T

PubMed Central

Li, Yan; Srinivasan, Radhika; Ratiney, Helene; Lu, Ying; Chang, Susan M.; Nelson, Sarah J.

2011-01-01

Purpose To measure T1 and T2 relaxation times of metabolites in glioma patients at 3T and to investigate how these values influence the observed metabolite levels. Materials and Methods Twenty-three patients with gliomas and ten volunteers were studied with single voxel 2D J-resolved PRESS using a 3T MR scanner. Voxels were chosen in normal appearing white matter and in regions of tumor. The T1 and T2 of choline containing compounds (Cho), creatine (Cr) and N-acetyl aspartate (NAA) were estimated. Results Metabolite T1 relaxation values in gliomas were not significantly different from values in normal white matter. The T2 of Cho and Cr were statistically significantly longer for Grade 4 gliomas than for normal white matter but the T2 of NAA was similar. These differences were large enough to impact the corrections of metabolite levels for relaxation times with tumor grade in terms of metabolite ratios (P<0.001). Conclusion The differential increase in T2 for Cho and Cr relative to NAA means that the ratios of Cho/NAA and Cr/NAA are higher in tumor at longer echo times relative to values in normal appearing brain. Having this information may be useful in defining the acquisition parameters for optimizing contrast between tumor and normal tissue in MRSI data, where limited time is available and only one echo time can be used. PMID:18666155

Nuclear Time Delay Effects on K-Vacancy Production in Deep-Inelastic U+U Collisions

NASA Astrophysics Data System (ADS)

Molitoris, John David

1987-09-01

Atomic K-vacancy production in 7.5-MeV/u U+U collisons has been studied for small-impact-parameter (b) elastic scattering and for deep-inelastic nuclear reactions, by measuring coincidences between U x-rays and scattered U particles. The K-vacancy production probability (P(,K)(b)) in elastic U+U collisions was measured as a function of b and it is shown that P(,K) follows a scaling law from b = 10 to 85 fm. Below 10 fm, P(,K)(b) increases sharply from 0.91 (+OR-) 0.08 at 11.6 fm to a maximum of 1.8 (+OR -) 0.18 vacancies per collison at 7 fm. This behavior at small b could be due to rotational coupling of the 2p(,3/2)(pi), 2p(,3/2)(sigma) (--->) 2p(,1/2)(sigma) molecular orbitals, but present theoretical calculations do not reflect this. Since internal conversion is a major background in these measurements, it was necessary to observe how the internal conversion changes in elastic collisions as b (--->) 0, so that the internal conversion for atomic collisons accompanied by nuclear reactions could be understood. Nuclear-reaction effects of P(,K)(b (DBLTURN) 0) were studied as a function of the total kinetic energy loss (TKEL) of the nuclear interaction for 2-body break -up (U + U (--->) U' + U'') and 3-body break-up (U + U ( --->) U' + 2ff). In 4-body break-up (U + U (--->) 2ff' + 2ff''), P(,K) was measured over all TKEL. In 2-body break-up a 78% reduction of P(,K) is observed between TKEL = 0 and 275 MeV. This trend matches a theoretical decrease in P(,K)(T(,D)), where T(,D) in the nuclear interaction time or delay time. A parametric relation between TKEL and T(,D) can be formed between the theoretical calculation and the experimental result. A delay time of (0.52 (+OR -) 0.17) x 10('-21) sec at TKEL = 100 MeV is deter- mined. There is overall agreement between this atomic physics result and nuclear diffusion model calculations. The measured P(,K)(TKEL) for 3-body break-up is nearly identical to that of 2-body break-up. This indicates that there is a large compo

The thermodynamic properties of 2-ethylhexyl acrylate over the temperature range from T → 0 to 350 K

NASA Astrophysics Data System (ADS)

Kulagina, T. G.; Samosudova, Ya. S.; Letyanina, I. A.; Sevast'yanov, E. V.; Smirnova, N. N.; Smirnova, L. A.; Mochalova, A. E.

2012-05-01

The temperature dependence of the heat capacity C {/p o}= f( T) 2 of 2-ethylhexyl acrylate was studied in an adiabatic vacuum calorimeter over the temperature range 6-350 K. Measurement errors were mainly of 0.2%. Glass formation and vitreous state parameters were determined. An isothermic shell calorimeter with a static bomb was used to measure the energy of combustion of 2-ethylhexyl acrylate. The experimental data were used to calculate the standard thermodynamic functions C {/p o}( T), H o( T)- H o(0), S o( T)- S o(0), and G o( T)- H o(0) of the compound in the vitreous and liquid states over the temperature range from T → 0 to 350 K, the standard enthalpies of combustion Δc H o, and the thermodynamic characteristics of formation Δf H o, Δf S o, and Δf G o at 298.15 K and p = 0.1 MPa.

Experimental investigation of a general real-time 3D target localization method using sequential kV imaging combined with respiratory monitoring

NASA Astrophysics Data System (ADS)

Cho, Byungchul; Poulsen, Per; Ruan, Dan; Sawant, Amit; Keall, Paul J.

2012-11-01

The goal of this work was to experimentally quantify the geometric accuracy of a novel real-time 3D target localization method using sequential kV imaging combined with respiratory monitoring for clinically realistic arc and static field treatment delivery and target motion conditions. A general method for real-time target localization using kV imaging and respiratory monitoring was developed. Each dimension of internal target motion T(x, y, z; t) was estimated from the external respiratory signal R(t) through the correlation between R(ti) and the projected marker positions p(xp, yp; ti) on kV images by a state-augmented linear model: T(x, y, z; t) = aR(t) + bR(t - τ) + c. The model parameters, a, b, c, were determined by minimizing the squared fitting error ∑‖p(xp, yp; ti) - P(θi) · (aR(ti) + bR(ti - τ) + c)‖2 with the projection operator P(θi). The model parameters were first initialized based on acquired kV arc images prior to MV beam delivery. This method was implemented on a trilogy linear accelerator consisting of an OBI x-ray imager (operating at 1 Hz) and real-time position monitoring (RPM) system (30 Hz). Arc and static field plans were delivered to a moving phantom programmed with measured lung tumour motion from ten patients. During delivery, the localization method determined the target position and the beam was adjusted in real time via dynamic multileaf collimator (DMLC) adaptation. The beam-target alignment error was quantified by segmenting the beam aperture and a phantom-embedded fiducial marker on MV images and analysing their relative position. With the localization method, the root-mean-squared errors of the ten lung tumour traces ranged from 0.7-1.3 mm and 0.8-1.4 mm during the single arc and five-field static beam delivery, respectively. Without the localization method, these errors ranged from 3.1-7.3 mm. In summary, a general method for real-time target localization using kV imaging and respiratory monitoring has been

Bio-, Magneto- and event-stratigraphy across the K-T boundary

NASA Technical Reports Server (NTRS)

Preisinger, A.; Stradner, H.; Mauritsch, H. J.

1988-01-01

Determining the time and the time structure of rare events in geology can be accomplished by applying three different and independent stratigraphic methods: Biostratigraphy, magneto-stratigraphy and event-stratigraphy. The optimal time resolution of the two former methods is about 1000 years, while by means of event-stratigraphy a resolution of approximately one year can be achieved. For biostratigraphy across the Cretaceous-Tertiary (K-T) boundary micro- and nannofossils have been found best suited. The qualitative and quantitative analyses of minerals and trace elements across the K-T boundary show anomalies on a millimeter scale and permit conclusions regarding the time structure of the K-T event itself. The results of the analyses find a most consistent explanation by the assumption of an extraterrestrial impact. The main portion of the material rain from the atmosphere evidently was deposited within a short time. The long-time components consist of the finest portion of the material rain from the atmosphere and the transported and redeposited fall-out.

RVxK2: Simultaneous PRV Program with Kepler/K2 Campaign 16

NASA Astrophysics Data System (ADS)

Xuesong Wang, Sharon; RVxK2 team

2018-01-01

Introducing the RVxK2 program: simultaneous precise radial velocity (PRV) observations with Kepler/K2 Campaign 16, from Dec 7 2017 through Feb 26 2018 (website: rvxk2.com). K2 will provide short cadence photometric data on five carefully selected stars, including the brightest M dwarf in C16 field, a solar analog, and three bright G/K subgiants. K2 will also provide long cadence data on the next three brightest K or M dwarfs in the C16 field. Our campaign includes several precise RV instruments around the globe, including Keck/HIRES, APF, IRTF/iSHELL, SONG, MINERVA, PARAS, representing the first organized, extensive, simultaneous RV campaign with space photometry. Our primary science goal is to characterize and understand stellar jitter and stellar activity. This RV+K2 campaign will provide the community with an unprecedented dataset of RV spectra and precise photometry to study stellar jitter on a broad range of time scales, from minutes to 80 days. We will gather the first ever RV+photometry dataset aiming at characterizing stellar granulation, the most poorly understood term among all astrophysical sources of stellar jitter. This project will also enable the first asteroseismic studies with simultaneous precise RVs and photometry, while searching for planets in the brightest nearby G to M dwarfs in the field.

Expression of K2P5.1 potassium channels on CD4+ T lymphocytes correlates with disease activity in rheumatoid arthritis patients.

PubMed

Bittner, Stefan; Bobak, Nicole; Feuchtenberger, Martin; Herrmann, Alexander M; Göbel, Kerstin; Kinne, Raimund W; Hansen, Anker J; Budde, Thomas; Kleinschnitz, Christoph; Frey, Oliver; Tony, Hans-Peter; Wiendl, Heinz; Meuth, Sven G

2011-02-11

CD4+ T cells express K(2P)5.1 (TWIK-related acid-sensitive potassium channel 2 (TASK2); KCNK5), a member of the two-pore domain potassium channel family, which has been shown to influence T cell effector functions. Recently, it was shown that K(2P)5.1 is upregulated upon (autoimmune) T cell stimulation. The aim of this study was to correlate expression levels of K(2P)5.1 on T cells from patients with rheumatoid arthritis (RA) to disease activity in these patients. Expression levels of K(2P)5.1 were measured by RT-PCR in the peripheral blood of 58 patients with RA and correlated with disease activity parameters (C-reactive protein levels, erythrocyte sedimentation rates, disease activity score (DAS28) scores). Twenty patients undergoing therapy change were followed-up for six months. Additionally, synovial fluid and synovial biopsies were investigated for T lymphocytes expressing K(2P)5.1. K(2P)5.1 expression levels in CD4+ T cells show a strong correlation to DAS28 scores in RA patients. Similar correlations were found for serological inflammatory parameters (erythrocyte sedimentation rate, C-reactive protein). In addition, K(2P)5.1 expression levels of synovial fluid-derived T cells are higher compared to peripheral blood T cells. Prospective data in individual patients show a parallel behaviour of K(2P)5.1 expression to disease activity parameters during a longitudinal follow-up for six months. Disease activity in RA patients correlates strongly with K(2P)5.1 expression levels in CD4+ T lymphocytes in the peripheral blood in cross-sectional as well as in longitudinal observations. Further studies are needed to investigate the exact pathophysiological mechanisms and to evaluate the possible use of K(2P)5.1 as a potential biomarker for disease activity and differential diagnosis.

Cluster analysis of quantitative MRI T2 and T1ρ relaxation times of cartilage identifies differences between healthy and ACL-injured individuals at 3T.

PubMed

Monu, U D; Jordan, C D; Samuelson, B L; Hargreaves, B A; Gold, G E; McWalter, E J

2017-04-01

To identify focal lesions of elevated MRI T 2 and T 1ρ relaxation times in articular cartilage of an ACL-injured group using a novel cluster analysis technique. Eighteen ACL-injured patients underwent 3T MRI T 2 and T 1ρ relaxometry at baseline, 6 months and 1 year and six healthy volunteers at baseline, 1 day and 1 year. Clusters of contiguous pixels above or below T 2 and T 1ρ intensity and area thresholds were identified on a projection map of the 3D femoral cartilage surface. The total area of femoral cartilage plate covered by clusters (%CA) was split into areas above (%CA+) and below (%CA-) the thresholds and the differences in %CA(+ or -) over time in the ACL-injured group were determined using the Wilcoxon signed rank test. %CA+ was greater in the ACL-injured patients than the healthy volunteers at 6 months and 1 year with average %CA+ of 5.2 ± 4.0% (p = 0.0054) and 6.6 ± 3.7% (p = 0.0041) for T 2 and 6.2 ± 7.1% (p = 0.063) and 8.2 ± 6.9% (p = 0.042) for T 1ρ , respectively. %CA- at 6 months and 1 year was 3.0 ± 1.8% (p > 0.1) and 5.9 ± 5.0% (p > 0.1) for T 2 and 4.4 ± 4.9% (p > 0.1) and 4.5 ± 4.6% (p > 0.1) for T 1ρ , respectively. With the proposed cluster analysis technique, we have quantified cartilage lesion coverage and demonstrated that the ACL-injured group had greater areas of elevated T 2 and T 1ρ relaxation times as compared to healthy volunteers. Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

EBOLA Ag K-SeT rapid test: field evaluation in Sierra Leone.

PubMed

Colavita, F; Biava, M; Mertens, P; Gilleman, Q; Borlon, C; Delli Guanti, M; Petrocelli, A; Cataldi, G; Kamara, A T; Kamara, S A; Konneh, K; Vincenti, D; Castilletti, C; Abdurahman, S; Mirazimi, A; Capobianchi, M R; Ippolito, G; Miccio, R; Di Caro, A

2018-06-01

Efficient interruption of Ebola virus disease (EVD) transmission chains critically depends on reliable and fast laboratory diagnosis. We evaluated the performance of the EBOLA Virus Antigen Detection K-SeT (EBOLA Ag K-SeT), a new rapid diagnostic antigen test in field settings. The study was conducted in a field laboratory located in Freetown (Sierra Leone) by the Italian National Institute for Infectious Diseases 'L. Spallanzani' and the EMERGENCY Onlus NGO. The EBOLA Ag K-SeT was tested on 210 residual plasma samples (EVD prevalence 50%) from patients hospitalized at the EMERGENCY Ebola treatment center in Goderich (Freetown), comparing the results with quantitative real-time PCR. Overall, the sensitivity of EBOLA Ag K-SeT was 88.6% (95% confidence interval (CI), 82.5-94.7), and the corresponding specificity was 98.1% (95% CI, 95.5-100.7). The positive and negative predictive values were 97.9% (95% CI, 95.0-100.8) and 89.6% (95% CI, 84-95.2), respectively. The sensitivity strongly increased up to 98.7% (95% CI, 96.1-101.2) for those samples with high virus load (≥6.2 log RNA copies/mL). Our results suggest that EBOLA Ag K-SeT could represent a new effective diagnostic tool for EVD, meeting a need for resource-poor settings and rapid diagnosis for individuals with suspected EVD. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Cryogenic test of the 4 K / 2 K insert for the ARIEL e-Linac cryomodule

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laxdal, R. E.; Ma, Y.; Harmer, P.

2014-01-29

The ARIEL project at TRIUMF requires a 50 MeV superconducting electron linac consisting of five nine cell 1.3 GHz cavities divided into three cryomodules with one, two and two cavities in each module respectively. LHe is distributed in parallel to each module at 4 K and at ∼1.2 bar. Each module has a cryogenic insert on board that receives the 4 K liquid and produces 2 K into a cavity phase separator. The module combines a 4 K phase separator, a plate and fin heat exchanger from DATE and a J-T valve expanding into the 2 K phase separator. Themore » unit also supplies 4 K liquid to thermal intercepts in the module in siphon loops that return the vaporized liquid to the 4 K reservoir. For testing purposes the unit is outfitted with a dummy 2 K phase separator and thermal intercepts with variable heaters that mimic the final heat loads in order to test the cryogenic performance. The design of the 4 K / 2 K insert, the results of the cold tests and a summary of the test infrastructure including cryogenics services will be presented.« less

NMR characterization of sulphur substitution effects in the K xFe 2-ySe 2-zS z high-T c superconductor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Torchetti, D. A.; Imai, T.; Lei, H. C.

2012-04-17

We present a⁷⁷ Se NMR study of the effect of S substitution in the high-T c superconductor K xFe 2-ySe 2-zS z in a temperature range up to 250 K. We examine two S concentrations, with z=0.8 (Tc~ 26 K) and z=1.6 (nonsuperconducting). The samples containing sulphur exhibit broader NMR line shapes than the K xFe₂Se₂ sample due to local disorder in the Se environment. Our Knight shift ⁷⁷K data indicate that in all samples, uniform spin susceptibility decreases with temperature, and that the magnitude of the Knight shift itself decreases with increased S concentration. In addition, S substitution progressivelymore » suppresses low-frequency spin fluctuations. None of the samples exhibit an enhancement of low-frequency antiferromagnetic spin fluctuations near T c in 1/T₁T, as seen in FeSe.« less

T2L2/Jason-2, first year of processing activities

NASA Astrophysics Data System (ADS)

Exertier, P.

2009-11-01

The T2L2 (Time Transfer by Laser Link) project, developed by CNES and OCA will permit the synchronization of remote ultra stable clocks and the determination of their performances over intercontinental distances. The principle is derived from laser telemetry technology with a dedicated space equipment designed to record arrival time of laser pulses at the satellite. T2L2 was accepted in 2005 to be on board the Jason-2 altimetry satellite. It has been successfully launched from Vandenberg (CA, US) in June 2008. T2L2 acquired the first laser pulses a few days after the launch. First analysis permitted to validate some important characteristics of the instrument such as sensitivity, noise, dynamic, event timer precision and ground to space time stability.

Constitutive Behavior and Processing Map of T2 Pure Copper Deformed from 293 to 1073 K

NASA Astrophysics Data System (ADS)

Liu, Ying; Xiong, Wei; Yang, Qing; Zeng, Ji-Wei; Zhu, Wen; Sunkulp, Goel

2018-02-01

The deformation behavior of T2 pure copper compressed from 293 to 1073 K with strain rates from 0.01 to 10 s-1 was investigated. The constitutive equations were established by the Arrhenius constitutive model, which can be expressed as a piecewise function of temperature with two sections, in the ranges 293-723 K and 723-1073 K. The processing maps were established according to the dynamic material model for strains of 0.2, 0.4, 0.6, and 0.8, and the optimal processing parameters of T2 copper were determined accordingly. In order to obtain a better understanding of the deformation behavior, the microstructures of the compressed samples were studied by electron back-scattered diffraction. The grains tend to be more refined with decreases in temperature and increases in strain rate.

Charged-current multiple pion production using νμ in the PøD in the T2K experiment

NASA Astrophysics Data System (ADS)

Davis, Scott

2013-04-01

The T2K experiment is a long-baseline, off-axis neutrino oscillation experiment designed to search for the appearance of νe in a νμ beam. The Pi-Zero Detector (PøD) of the T2K off-axis near detector (ND280) is used to measure properties of the neutrino beam and measure cross sections relevant to the beam's energy. As the PøD contains a variety of nuclei, we can measure the cross section of various production modes on several targets. At the beam energies of T2K, the production of multiple pions, of any type, from neutrinos is not well understood. I will present the status of an analysis method to measure the production of multiple (2 or greater) pions from a charged-current interaction with νμ.

Estimation of Spatiotemporal Sensitivity Using Band-limited Signals with No Additional Acquisitions for k-t Parallel Imaging.

PubMed

Takeshima, Hidenori; Saitoh, Kanako; Nitta, Shuhei; Shiodera, Taichiro; Takeguchi, Tomoyuki; Bannae, Shuhei; Kuhara, Shigehide

2018-03-13

Dynamic MR techniques, such as cardiac cine imaging, benefit from shorter acquisition times. The goal of the present study was to develop a method that achieves short acquisition times, while maintaining a cost-effective reconstruction, for dynamic MRI. k - t sensitivity encoding (SENSE) was identified as the base method to be enhanced meeting these two requirements. The proposed method achieves a reduction in acquisition time by estimating the spatiotemporal (x - f) sensitivity without requiring the acquisition of the alias-free signals, typical of the k - t SENSE technique. The cost-effective reconstruction, in turn, is achieved by a computationally efficient estimation of the x - f sensitivity from the band-limited signals of the aliased inputs. Such band-limited signals are suitable for sensitivity estimation because the strongly aliased signals have been removed. For the same reduction factor 4, the net reduction factor 4 for the proposed method was significantly higher than the factor 2.29 achieved by k - t SENSE. The processing time is reduced from 4.1 s for k - t SENSE to 1.7 s for the proposed method. The image quality obtained using the proposed method proved to be superior (mean squared error [MSE] ± standard deviation [SD] = 6.85 ± 2.73) compared to the k - t SENSE case (MSE ± SD = 12.73 ± 3.60) for the vertical long-axis (VLA) view, as well as other views. In the present study, k - t SENSE was identified as a suitable base method to be improved achieving both short acquisition times and a cost-effective reconstruction. To enhance these characteristics of base method, a novel implementation is proposed, estimating the x - f sensitivity without the need for an explicit scan of the reference signals. Experimental results showed that the acquisition, computational times and image quality for the proposed method were improved compared to the standard k - t SENSE method.

Carbon isotopic compositions of organic matter across continental Cretaceous-Tertiary (K-T) boundary sections: Implications for paleoenvironment after the K-T impact event

USGS Publications Warehouse

Maruoka, T.; Koeberl, C.; Bohor, B.F.

2007-01-01

To assess the environmental perturbation induced by the impact event that marks the Cretaceous-Tertiary (K-T) boundary, concentrations and isotopic compositions of bulk organic carbon were determined in sedimentary rocks that span the terrestrial K-T boundary at Dogie Creek, Montana, and Brownie Butte, Wyoming in the Western Interior of the United States. The boundary clays at both sites are not bounded by coals. Although coals consist mainly of organic matter derived from plant tissue, siliceous sedimentary rocks, such as shale and clay, may contain organic matter derived from microbiota as well as plants. Coals record ??13C values of plant-derived organic matter, reflecting the ??13C value of atmospheric CO2, whereas siliceous sedimentary rocks record the ??13C values of organic matter derived from plants and microbiota. The microbiota ??13C value reflects not only the ??13C value of atmospheric CO2, but also biological productivity. Therefore, the siliceous rocks from these sites yields information that differs from that obtained previously from coal beds. Across the freshwater K-T boundary at Brownie Butte, the ??13C values decrease by 2.6??? (from - 26.15??? below the boundary clay to - 28.78??? above the boundary clay), similar to the trend in carbonate at marine K-T sites. This means that the organic ??13C values reflect the variation of ??13C of atmospheric CO2, which is in equilibrium with carbon isotopes at the ocean surface. Although a decrease in ??13C values is observed across the K-T boundary at Dogie Creek (from - 25.32??? below the boundary clay to - 26.11??? above the boundary clay), the degree of ??13C-decrease at Dogie Creek is smaller than that at Brownie Butte and that for marine carbonate. About 2??? decrease in ??13C of atmospheric CO2 was expected from the ??13C variation of marine carbonate at the K-T boundary. This ??13C-decrease of atmospheric CO2 should affect the ??13C values of organic matter derived from plant tissue. As such a

Recent Results from the T2K Experiment

NASA Astrophysics Data System (ADS)

Abe, K.; Abgrall, N.; Aihara, H.; Akiri, T.; Andreopoulos, C.; Aoki, S.; Ariga, A.; Ariga, T.; Assylbekov, S.; Autiero, D.; Barbi, M.; Barker, G. J.; Barr, G.; Bass, M.; Batkiewicz, M.; Bay, F.; Bentham, S. W.; Berardi, V.; Berger, B. E.; Berkman, S.; Bertram, I.; Bhadra, S.; Blaszczyk, F. D. M.; Blondel, A.; Bojechko, C.; Boyd, S. B.; Brailsford, D.; Bravar, A.; Bronner, C.; Buchanan, N.; Calland, R. G.; Caravaca Rodríguez, J.; Cartwright, S. L.; Castillo, R.; Catanesi, M. G.; Cervera, A.; Cherdack, D.; Christodoulou, G.; Clifton, A.; Coleman, J.; Coleman, S. J.; Collazuol, G.; Connolly, K.; Cremonesi, L.; Curioni, A.; Dabrowska, A.; Danko, I.; Das, R.; Davis, S.; de Perio, P.; De Rosa, G.; Dealtry, T.; Dennis, S. R.; Densham, C.; Di Lodovico, F.; Di Luise, S.; Drapier, O.; Duboyski, T.; Dufour, F.; Dumarchez, J.; Dytman, S.; Dziewiecki, M.; Emery, S.; Ereditato, A.; Escudero, L.; Finch, A. J.; Frank, E.; Friend, M.; Fujii, Y.; Fukuda, Y.; Furmanski, A. P.; Galymov, V.; Gaudin, A.; Giffin, S.; Giganti, C.; Gilje, K.; Golan, T.; Gomez-Cadenas, J. J.; Gonin, M.; Grant, N.; Gudin, D.; Hadley, D. R.; Haesler, A.; Haigh, M. D.; Hamilton, P.; Hansen, D.; Hara, T.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayato, Y.; Hearty, C.; Helmer, R. L.; Hierholzer, M.; Hignight, J.; Hillairet, A.; Himmel, A.; Hiraki, T.; Hirota, S.; Holeczek, J.; Horikawa, S.; Huang, K.; Ichikawa, A. K.; Ieki, K.; Ieva, M.; Ikeda, M.; Imber, J.; Insler, J.; Irvine, T. J.; Ishida, T.; Ishii, T.; Ives, S. J.; Iyogi, K.; Izmaylov, A.; Jacob, A.; Jamieson, B.; Johnson, R. A.; Jo, J. H.; Jonsson, P.; Joo, K. K.; Jung, C. K.; Kaboth, A. C.; Kajita, T.; Kakuno, H.; Kameda, J.; Kanazawa, Y.; Karlen, D.; Karpikov, I.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kielczewska, D.; Kikawa, T.; Kilinski, A.; Kim, J.; Kim, S. B.; Kisiel, J.; Kitching, P.; Kobayashi, T.; Kogan, G.; Kolaceke, A.; Konaka, A.; Kormos, L. L.; Korzenev, A.; Koseki, K.; Koshio, Y.; Kreslo, I.; Kropp, W.; Kubo, H.; Kudenko, Y.; Kumaratunga, S.; Kurjata, R.; Kutter, T.; Lagoda, J.; Laihem, K.; Laveder, M.; Lawe, M.; Lazos, M.; Lee, K. P.; Licciardi, C.; Lim, I. T.; Lindner, T.; Lister, C.; Litchfield, R. P.; Longhin, A.; Lopez, G. D.; Ludovici, L.; Macaire, M.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Marino, A. D.; Marteau, J.; Martin, J. F.; Maruyama, T.; Marzec, J.; Masliah, P.; Mathie, E. L.; Matveev, V.; Mavrokoridis, K.; Mazzucato, E.; McCauley, N.; McFarland, K. S.; McGrew, C.; Metelko, C.; Mijakowski, P.; Miller, C. A.; Minamino, A.; Mineev, O.; Mine, S.; Missert, A.; Miura, M.; Monfregola, L.; Moriyama, S.; Mueller, Th. A.; Murakami, A.; Murdoch, M.; Murphy, S.; Myslik, J.; Nagasaki, T.; Nakadaira, T.; Nakahata, M.; Nakai, T.; Nakamura, K.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; O'Keeffe, H. M.; Ohta, R.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Otani, M.; Owen, R. A.; Oyama, Y.; Pac, M. Y.; Palladino, V.; Paolone, V.; Payne, D.; Pearce, G. F.; Perevozchikov, O.; Perkin, J. D.; Petrov, Y.; Pinzon Guerra, E. S.; Pistillo, C.; Plonski, P.; Poplawska, E.; Popov, B.; Posiadala, M.; Poutissou, J.-M.; Poutissou, R.; Przewlocki, P.; Quilain, B.; Radicioni, E.; Ratoff, P. N.; Ravonel, M.; Rayner, M. A. M.; Redij, A.; Reeves, M.; Reinherz-Aronis, E.; Retiere, F.; Robert, A.; Rodrigues, P. A.; Rondio, E.; Roth, S.; Rubbia, A.; Ruterbories, D.; Sacco, R.; Sakashita, K.; Sánchez, F.; Scantamburlo, E.; Scholberg, K.; Schwehr, J.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sgalaberna, D.; Shiozawa, M.; Short, S.; Shustrov, Y.; Sinclair, P.; Smith, B.; Smith, R. J.; Smy, M.; Sobczyk, J. T.; Sobel, H.; Sorel, M.; Southwell, L.; Stamoulis, P.; Steinmann, J.; Still, B.; Suda, Y.; Suzuki, A.; Suzuki, K.; Suzuki, S. Y.; Suzuki, Y.; Szeglowski, T.; Tacik, R.; Tada, M.; Takahashi, S.; Takeda, A.; Takeuchi, Y.; Tanaka, H. A.; Tanaka, M. M.; Taylor, I. J.; Terhorst, D.; Terri, R.; Thompson, L. F.; Thorley, A.; Tobayama, S.; Toki, W.; Tomura, T.; Totsuka, Y.; Touramanis, C.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Ueno, K.; Vacheret, A.; Vagins, M.; Vasseur, G.; Wachala, T.; Waldron, A. V.; Walter, C. W.; Wark, D.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilkes, R. J.; Wilking, M. J.; Wilkinson, C.; Williamson, Z.; Wilson, J. R.; Wilson, R. J.; Wongjirad, T.; Yamada, Y.; Yamamoto, K.; Yanagisawa, C.; Yen, S.; Yershov, N.; Yokoyama, M.; Yuan, T.; Zalewska, A.; Zalipska, J.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Żmuda, J.

2014-01-01

The Tokai to Kamioka (T2K) experiment studies neutrino oscillations using a beam of muon neutrinos produced by an accelerator. The neutrinos travel from J-PARC on the east coast of Japan and are detected 295 kilometers further away in the Super-Kamiokande detector. A complex of near detectors located 280 meters away from the neutrino production target is used to better characterize the neutrino beam and reduce systematic uncertainties. The experiment aims at measuring electronic neutrino appearance (νμ →νe oscillation) to measure the neutrino mixing angle θ13, and muon neutrino disappearance to measure the neutrino mixing angle θ23 and mass splitting | Δ m322 |. We report here electron neutrino appearance results using three years of data, recorded until the 2012 summer, as well as muon neutrino disappearance results based on the data coming from the first two years of the experiment.

Magnetic resonance transverse relaxation time T2 of knee cartilage in osteoarthritis at 3-T: a cross-sectional multicentre, multivendor reproducibility study.

PubMed

Balamoody, Sharon; Williams, Tomos G; Wolstenholme, Chris; Waterton, John C; Bowes, Michael; Hodgson, Richard; Zhao, Sha; Scott, Marietta; Taylor, Chris J; Hutchinson, Charles E

2013-04-01

The transverse relaxation time (T2) in MR imaging has been identified as a potential biomarker of hyaline cartilage pathology. This study investigates whether MR assessments of T2 are comparable between 3-T scanners from three different vendors. Twelve subjects with symptoms of knee osteoarthritis and one or more risk factors had their knee scanned on each of the three vendors' scanners located in three sites in the U.K. MR data acquisition was based on the United States National Institutes of Health Osteoarthritis Initiative protocol. Measures of cartilage T2 and R2 (inverse of T2) were computed for precision error assessment. Intrascanner reproducibility was also assessed with a phantom (all three scanners) and a cohort of 5 subjects (one scanner only). Whole-organ magnetic resonance (WORM) semiquantitative cartilage scores ranged from minimal to advanced degradation. Intrascanner R2 root-mean-square coefficients of variation (RMSCOV) were low, within the range 2.6 to 6.3% for femoral and tibial regions. For one scanner pair, mean T2 differences ranged from -1.2 to 2.8 ms, with no significant difference observed for the medial tibia and patella regions (p < 0.05). T2 values from the third scanner were systematically lower, producing interscanner mean T2 differences within the range 5.4 to 10.0 ms. Significant interscanner cartilage T2 differences were found and should be accounted for before data from scanners of different vendors are compared.

Young Engineers and Scientists (YES 2K6): Independent and Group Mentorship Projects

NASA Astrophysics Data System (ADS)

Boice, D. C.; Asbell, H. E.

2006-12-01

The Young Engineers and Scientists (YES) Program is a community partnership between Southwest Research Institute (SwRI), and local high schools in San Antonio, Texas (USA). YES has been highly successful during the past 14 years, and YES 2K6 continued this trend. It provides talented high school juniors and seniors a bridge between classroom instruction and real-world, research experiences in physical sciences and engineering. YES 2K6 consists of two parts: 1) a three-week summer workshop and 2) a mentorship where students complete individual research projects during their academic year. The intensive workshop is held at SwRI where students experience the research environment first-hand. They also develop skills and acquire tools for solving scientific problems, attend mini-courses and seminars on electronics, computers and the Internet, careers, science ethics, and other topics; and select individual research projects to be completed during the academic year. YES 2K6 students developed a website for the Magnetospheric Multiscale (MMS) Mission from the perspective of a high school student. The collegial mentorship takes place during their academic year where students complete individual research projects under the guidance of their mentors and earn honors credit. At the end of the school year, students publicly present and display their work at their schools. This acknowledges their accomplishments and spreads career awareness to other students and teachers. Over the past 14 years, all YES graduates have entered college, several have worked for SwRI, and three scientific publications have resulted. Student evaluations indicate the benefits of YES for their academic preparation and choice of college majors. We acknowledge E/PO funding from the NASA MMS Mission and local charitable foundations.

A study of the reaction Li+HCl by the technique of time-resolved laser-induced fluorescence spectroscopy of Li (2 2PJ-2 2S1/2, λ=670.7 nm) between 700 and 1000 K

NASA Astrophysics Data System (ADS)

Plane, John M. C.; Saltzman, Eric S.

1987-10-01

A kinetic study is presented of the reaction between lithium atoms and hydrogen chloride over the temperature range 700-1000 K. Li atoms are produced in an excess of HCl and He bath gas by pulsed photolysis of LiCl vapor. The concentration of the metal atoms is then monitored in real time by the technique of laser-induced fluorescence of Li atoms at λ=670.7 nm using a pulsed nitrogen-pumped dye laser and box-car integration of the fluorescence signal. Absolute second-order rate constants for this reaction have been measured at T=700, 750, 800, and 900 K. At T=1000 K the reverse reaction is sufficiently fast that equilibrium is rapidly established on the time scale of the experiment. A fit of the data between 700 and 900 K to the Arrhenius form, with 2σ errors calculated from the absolute errors in the rate constants, yields k(T)=(3.8±1.1)×10-10 exp[-(883±218)/T] cm3 molecule-1 s-1. This result is interpreted through a modified form of collision theory which is constrained to take account of the conservation of total angular momentum during the reaction. Thereby we obtain an estimate for the reaction energy threshold, E0=8.2±1.4 kJ mol-1 (where the error arises from uncertainty in the exothermicity of the reaction), in very good agreement with a crossed molecular beam study of the title reaction, and substantially lower than estimates of E0 from both semiempirical and ab initio calculations of the potential energy surface.

SLUDGE TREATMENT PROJECT PHASE 1 SLUDGE STORAGE OPTIONS ASSESSMENT OF T PLANT VERSUS ALTERNATE STORAGE FACILITY

DOE Office of Scientific and Technical Information (OSTI.GOV)

RUTHERFORD WW; GEUTHER WJ; STRANKMAN MR

2009-04-29

The CH2M HILL Plateau Remediation Company (CHPRC) has recommended to the U.S. Department of Energy (DOE) a two phase approach for removal and storage (Phase 1) and treatment and packaging for offsite shipment (Phase 2) of the sludge currently stored within the 105-K West Basin. This two phased strategy enables early removal of sludge from the 105-K West Basin by 2015, allowing remediation of historical unplanned releases of waste and closure of the 100-K Area. In Phase 1, the sludge currently stored in the Engineered Containers and Settler Tanks within the 105-K West Basin will be transferred into sludge transportmore » and storage containers (STSCs). The STSCs will be transported to an interim storage facility. In Phase 2, sludge will be processed (treated) to meet shipping and disposal requirements and the sludge will be packaged for final disposal at a geologic repository. The purpose of this study is to evaluate two alternatives for interim Phase 1 storage of K Basin sludge. The cost, schedule, and risks for sludge storage at a newly-constructed Alternate Storage Facility (ASF) are compared to those at T Plant, which has been used previously for sludge storage. Based on the results of the assessment, T Plant is recommended for Phase 1 interim storage of sludge. Key elements that support this recommendation are the following: (1) T Plant has a proven process for storing sludge; (2) T Plant storage can be implemented at a lower incremental cost than the ASF; and (3) T Plant storage has a more favorable schedule profile, which provides more float, than the ASF. Underpinning the recommendation of T Plant for sludge storage is the assumption that T Plant has a durable, extended mission independent of the K Basin sludge interim storage mission. If this assumption cannot be validated and the operating costs of T Plant are borne by the Sludge Treatment Project, the conclusions and recommendations of this study would change. The following decision-making strategy

A Measurement of the νμ Charged Current Quasielastic Cross-section on Water with T2K's Near Detector

NASA Astrophysics Data System (ADS)

Yuan, Tianlu; Lopez, Jeremy; Marino, Alysia; T2K Collaboration

2015-04-01

The T2K experiment has collected an impressive amount of data the past few years useful for both oscillation analyses and precision measurements. Its near-detector, ND280, comprising of several sub-detectors, include water targets that allow for the extraction of a water-based cross-section measurement. We present a selection of νμ charged current events occurring within the Pi-Zero Detector (PØD). The charged, outgoing tracks are required to enter and be identified by the Tracker of T2K's near-detector. Our sample corresponds to approximately 6 × 1020 protons on target. The cross section is determined using an iterative Baysian unfolding technique, which includes all systematic uncertainties. By separating the dataset into time periods when the PØD is filled with water and when it is empty, a subtraction method provides a distribution of νμ interactions on water only. In this way, we produce a measurement of the νμ CCQE cross-section on water.

Radial k-t SPIRiT: autocalibrated parallel imaging for generalized phase-contrast MRI.

PubMed

Santelli, Claudio; Schaeffter, Tobias; Kozerke, Sebastian

2014-11-01

To extend SPIRiT to additionally exploit temporal correlations for highly accelerated generalized phase-contrast MRI and to compare the performance of the proposed radial k-t SPIRiT method relative to frame-by-frame SPIRiT and radial k-t GRAPPA reconstruction for velocity and turbulence mapping in the aortic arch. Free-breathing navigator-gated two-dimensional radial cine imaging with three-directional multi-point velocity encoding was implemented and fully sampled data were obtained in the aortic arch of healthy volunteers. Velocities were encoded with three different first gradient moments per axis to permit quantification of mean velocity and turbulent kinetic energy. Velocity and turbulent kinetic energy maps from up to 14-fold undersampled data were compared for k-t SPIRiT, frame-by-frame SPIRiT, and k-t GRAPPA relative to the fully sampled reference. Using k-t SPIRiT, improvements in magnitude and velocity reconstruction accuracy were found. Temporally resolved magnitude profiles revealed a reduction in spatial blurring with k-t SPIRiT compared with frame-by-frame SPIRiT and k-t GRAPPA for all velocity encodings, leading to improved estimates of turbulent kinetic energy. k-t SPIRiT offers improved reconstruction accuracy at high radial undersampling factors and hence facilitates the use of generalized phase-contrast MRI for routine use. Copyright © 2013 Wiley Periodicals, Inc.

The inverse sandwich complex [(K(18-crown-6))2Cp][CpFe(CO)2]--unpredictable redox reactions of [CpFe(CO)2]I with the silanides Na[SiRtBu2] (R = Me, tBu) and the isoelectronic phosphanyl borohydride K[PtBu2BH3].

PubMed

Sänger, Inge; Kückmann, Theresa I; Dornhaus, Franz; Bolte, Michael; Wagner, Matthias; Lerner, Hans-Wolfram

2012-06-14

The dimeric iron carbonyl [CpFe(CO)(2)](2) and the iodosilanes tBu(2)RSiI were obtained from the reaction of [CpFe(CO)(2)]I with the silanides Na[SiRtBu(2)] (R = Me, tBu) in THF. By the reactions of [CpFe(CO)(2)]I and Na[SiRtBu(2)] (R = Me, tBu) the disilanes tBu(2)RSiSiRtBu(2) (R = Me, tBu) were additionally formed using more than one equivalent of the silanide. In this context it should be noted that reduction of [CpFe(CO)(2)](2) with Na[SitBu(3)] gives the disilanes tBu(3)SiSitBu(3) along with the sodium ferrate [(Na(18-crown-6))(2)Cp][CpFe(CO)(2)]. The potassium analogue [(K(18-crown-6))(2)Cp][CpFe(CO)(2)] (orthorhombic, space group Pmc2(1)), however, could be isolated as a minor product from the reaction of [CpFe(CO)(2)]I with [K(18-crown-6)][PtBu(2)BH(3)]. The reaction of [CpFe(CO)(2)](2) with the potassium benzophenone ketyl radical and subsequent treatment with 18-crown-6 yielded the ferrate [K(18-crown-6)][CpFe(CO)(2)] in THF at room temperature. The crown ether complex [K(18-crown-6)][CpFe(CO)(2)] was analyzed using X-ray crystallography (orthorhombic, space group Pna2(1)) and its thermal behaviour was investigated.

Simultaneous acquisition for T2 -T2 Exchange and T1 -T2 correlation NMR experiments

NASA Astrophysics Data System (ADS)

Montrazi, Elton T.; Lucas-Oliveira, Everton; Araujo-Ferreira, Arthur G.; Barsi-Andreeta, Mariane; Bonagamba, Tito J.

2018-04-01

The NMR measurements of longitudinal and transverse relaxation times and its multidimensional correlations provide useful information about molecular dynamics. However, these experiments are very time-consuming, and many researchers proposed faster experiments to reduce this issue. This paper presents a new way to simultaneously perform T2 -T2 Exchange and T1 -T2 correlation experiments by taking the advantage of the storage time and the two steps phase cycling used for running the relaxation exchange experiment. The data corresponding to each step is either summed or subtracted to produce the T2 -T2 and T1 -T2 data, enhancing the information obtained while maintaining the experiment duration. Comparing the results from this technique with traditional NMR experiments it was possible to validate the method.

Measuring the Muon Neutrino Charged Current Cross Section on Water using the Near Detector of T2K

NASA Astrophysics Data System (ADS)

Das, Rajarshi

2012-10-01

The Near Detector of the T2K Long Baseline Neutrino Oscillation Experiment comprises of several sub-detectors working together to study neutrino interactions. The neutrinos are provided by a powerful off-axis, accelerator generated neutrino beam located at the J-PARC facility in Tokai, Japan. The first sub-detector in the path of travelling neutrinos, the Pi-Zero Detector (P0D), is made of layers of scintillating plastic, lead, brass and bags of water. The next sub-detector, the Tracker, consists of alternating Time Projection Chambers (TPC) and Fine Grained scintillator Detectors (FGD). We outline the procedure for extracting a muon neutrino charged current cross section on water-only by selecting muons originating in the P0D and travelling through the Tracker. We compare data collected while the P0D water bags are filled with water against data from P0D water bags filled with air. A detailed detector simulation utilizing NEUT and GENIE neutrino interaction generators is used in conjunction with a Bayesian Unfolding scheme to correct for detector effects in the data. The end result is a model-independent double differential neutrino cross section as a function of muon momentum and direction.

The tumor suppressor SirT2 regulates cell cycle progression and genome stability by modulating the mitotic deposition of H4K20 methylation

PubMed Central

Serrano, Lourdes; Martínez-Redondo, Paloma; Marazuela-Duque, Anna; Vazquez, Berta N.; Dooley, Scott J.; Voigt, Philipp; Beck, David B.; Kane-Goldsmith, Noriko; Tong, Qiang; Rabanal, Rosa M.; Fondevila, Dolors; Muñoz, Purificación; Krüger, Marcus; Tischfield, Jay A.; Vaquero, Alejandro

2013-01-01

The establishment of the epigenetic mark H4K20me1 (monomethylation of H4K20) by PR-Set7 during G2/M directly impacts S-phase progression and genome stability. However, the mechanisms involved in the regulation of this event are not well understood. Here we show that SirT2 regulates H4K20me1 deposition through the deacetylation of H4K16Ac (acetylation of H4K16) and determines the levels of H4K20me2/3 throughout the cell cycle. SirT2 binds and deacetylates PR-Set7 at K90, modulating its chromatin localization. Consistently, SirT2 depletion significantly reduces PR-Set7 chromatin levels, alters the size and number of PR-Set7 foci, and decreases the overall mitotic deposition of H4K20me1. Upon stress, the interaction between SirT2 and PR-Set7 increases along with the H4K20me1 levels, suggesting a novel mitotic checkpoint mechanism. SirT2 loss in mice induces significant defects associated with defective H4K20me1–3 levels. Accordingly, SirT2-deficient animals exhibit genomic instability and chromosomal aberrations and are prone to tumorigenesis. Our studies suggest that the dynamic cross-talk between the environment and the genome during mitosis determines the fate of the subsequent cell cycle. PMID:23468428

Magnetic microspherules associated with the K/T and upper Eocene extinction events

NASA Technical Reports Server (NTRS)

Cisowski, Stanley M.

1988-01-01

Magnetic microspherules were identified in over 20 K/T boundary sites, and in numerous Deep Sea Drilling Project (DSDP) cores from the Caribbean and Pacific, synchronous with the extinction of several radiolarian species near the end of the Eocene. The K/T magnetic spherules are of particular interest as carriers of Ir and other siderophiles generally found in abundance in K/T boundary clay. Furthermore the textures and unusual chemistry of their component magnetic phases indicate an origin at high temperature, possibly related to (an) unusual event(s) marking the end of the Cretaceous and Eocene periods. Their origin, along with the non-magnetic (sanidine) spheules, is generally ascribed directly to megaimpact events hypothesized to have periodically disrupted life on Earth. A survey of microspherical forms associated with known meteorite and impact derived materials reveals fundamental differences from the extinction related spherules. Low temperature magnetic experiments on the K/T and Upper Eocene spheroids indicate that, unlike tektites, extremely small superparamagnetic carriers are not present in abundance. The extensive subaerial exposure of Cretaceous combustible black shale during sea level regression in the latest Cretaceous represents a potential source for the magnetic spheroids found in certain K/T boundary clays. The recent discovery of high Ir abundances distributed above and below the K/T boundary within shallow water sediments in Israel, which also contain the most extensive known zones of combustion metamorphism, the so called Mottled Zone, adds a further dramatic footnote to the proposed association between the magnetic spheroids and combustion of organic shales. Interestingly, the Mottled Zone also contains the rare mineral magnesioferrite, which was identified both within the K/T magnetic spheroids and as discrete crystals in boundary clay from marine and continental sites.

The Power of Cooperation in International Paleoclimate Science: Examples from the PAGES 2k Network and the Ocean2k Working Group

NASA Astrophysics Data System (ADS)

Addison, J. A.

2015-12-01

The Past Global Changes (PAGES) project of IGBP and Future Earth supports research to understand the Earth's past environment to improve future climate predictions and inform strategies for sustainability. Within this framework, the PAGES 2k Network was established to provide a focus on the past 2000 years, a period that encompasses Medieval Climate Anomaly warming, Little Ice Age cooling, and recent anthropogenically-forced climate change. The results of these studies are used for testing earth system models, and for understanding decadal- to centennial-scale variability, which is needed for long-term planning. International coordination and cooperation among the nine regional Working Groups that make up the 2k Network has been critical to the success of PAGES 2k. The collaborative approach is moving toward scientific achievements across the regional groups, including: (i) the development of a community-driven open-access proxy climate database; (ii) integration of multi-resolution proxy records; (iii) development of multivariate climate reconstructions; and (iv) a leap forward in the spatial resolution of paleoclimate reconstructions. The last addition to the 2k Network, the Ocean2k Working Group has further innovated the collaborative approach by: (1) creating an open, receptive environment to discuss ideas exclusively in the virtual space; (2) employing an array of real-time collaborative software tools to enable communication, group document writing, and data analysis; (3) consolidating executive leadership teams to oversee project development and manage grassroots-style volunteer pools; and (4) embracing the value-added role that international and interdisciplinary science can play in advancing paleoclimate hypotheses critical to understanding future change. Ongoing efforts for the PAGES 2k Network are focused on developing new standards for data quality control and archiving. These tasks will provide the foundation for new and continuing "trans-regional" 2k

HIV-1 Infection of Primary CD4+ T Cells Regulates the Expression of Specific Human Endogenous Retrovirus HERV-K (HML-2) Elements.

PubMed

Young, George R; Terry, Sandra N; Manganaro, Lara; Cuesta-Dominguez, Alvaro; Deikus, Gintaras; Bernal-Rubio, Dabeiba; Campisi, Laura; Fernandez-Sesma, Ana; Sebra, Robert; Simon, Viviana; Mulder, Lubbertus C F

2018-01-01

Endogenous retroviruses (ERVs) occupy extensive regions of the human genome. Although many of these retroviral elements have lost their ability to replicate, those whose insertion took place more recently, such as the HML-2 group of HERV-K elements, still retain intact open reading frames and the capacity to produce certain viral RNA and/or proteins. Transcription of these ERVs is, however, tightly regulated by dedicated epigenetic control mechanisms. Nonetheless, it has been reported that some pathological states, such as viral infections and certain cancers, coincide with ERV expression, suggesting that transcriptional reawakening is possible. HML-2 elements are reportedly induced during HIV-1 infection, but the conserved nature of these elements has, until recently, rendered their expression profiling problematic. Here, we provide comprehensive HERV-K HML-2 expression profiles specific for productively HIV-1-infected primary human CD4 + T cells. We combined enrichment of HIV-1 infected cells using a reporter virus expressing a surface reporter for gentle and efficient purification with long-read single-molecule real-time sequencing. We show that three HML-2 proviruses-6q25.1, 8q24.3, and 19q13.42-are upregulated on average between 3- and 5-fold in HIV-1-infected CD4 + T cells. One provirus, HML-2 12q24.33, in contrast, was repressed in the presence of active HIV replication. In conclusion, this report identifies the HERV-K HML-2 loci whose expression profiles differ upon HIV-1 infection in primary human CD4 + T cells. These data will help pave the way for further studies on the influence of endogenous retroviruses on HIV-1 replication. IMPORTANCE Endogenous retroviruses inhabit big portions of our genome. Moreover, although they are mainly inert, some of the evolutionarily younger members maintain the ability to express both RNA and proteins. We have developed an approach using long-read single-molecule real-time (SMRT) sequencing that produces long reads that

The Rate Constant for the Reaction H + C2H5 at T = 295 - 150K

NASA Technical Reports Server (NTRS)

Pimentel, Andre S.; Payne, Walter A.; Nesbitt, Fred L.; Cody, Regina J.; Stief, Louis J.

2004-01-01

The reaction between the hydrogen atom and the ethyl (C2H3) radical is predicted by photochemical modeling to be the most important loss process for C2H5 radicals in the atmospheres of Jupiter and Saturn. This reaction is also one of the major sources for the methyl radicals in these atmospheres. These two simplest hydrocarbon radicals are the initial species for the synthesis of larger hydrocarbons. Previous measurements of the rate constant for the H + C2H5 reaction varied by a factor of five at room temperature, and some studies showed a dependence upon temperature while others showed no such dependence. In addition, the previous studies were at higher temperatures and generally higher pressures than that needed for use in planetary atmospheric models. The rate constant for the reaction H + C2H5 has been measured directly at T = 150, 202 and 295 K and at P = 1.0 Torr He for all temperatures and additionally at P = 0.5 and 2.0 Torr He at T = 202 K. The measurements were performed in a discharge - fast flow system. The decay of the C2H5 radical in the presence of excess hydrogen was monitored by low-energy electron impact mass spectrometry under pseudo-first order conditions. H atoms and C2H5 radicals were generated rapidly and simultaneously by the reaction of fluorine atoms with H2 and C2H6, respectively. The total rate constant was found to be temperature and pressure independent. The measured total rate constant at each temperature are: k(sub 1)(295K) = (1.02+/-0.24)x10(exp -10), k(sub 1)(202K) = (1.02+/-0.22)x10(exp -10) and k(sub 1)(150K) = (0.93+/-0.21)x10(exp -10), all in units of cu cm/molecule/s. The total rate constant derived from all the combined measurements is k(sub 1) = (l.03+/-0.17)x10(exp -10) cu cm/molecule/s. At room temperature our results are about a factor of two higher than the recommended rate constant and a factor of three lower than the most recently published study.

Effect of vitamin K2 on type 2 diabetes mellitus: A review.

PubMed

Li, Yan; Chen, Jie Peng; Duan, Lili; Li, Shuzhuang

2018-02-01

Type 2 diabetes mellitus (T2DM) continue to be a major public health problem around the world that frequently presents with microvascular and macrovascular complications. Individuals with T2DM are not only suffering from significant emotional and physical misery, but also at increased risk of dying from severe complications. In recent years, evidence from prospective observational studies and clinical trials has shown T2DM risk reduction with vitamin K2 supplementation. We thus did an overview of currently available studies to assess the effect of vitamin K2 supplementation on insulin sensitivity, glycaemic control and reviewed the underlying mechanisms. We proposed that vitamin K2 improved insulin sensitivity through involvement of vitamin K-dependent-protein osteocalcin, anti-inflammatory properties, and lipid-lowering effects. Vitamin K2 had a better effect than vitamin K1 on T2DM. The interpretation of this review will increase comprehension of the development of a therapeutic strategy to prevent and treat T2DM. Copyright © 2017 Elsevier B.V. All rights reserved.

Magnetic resonance fingerprinting using echo-planar imaging: Joint quantification of T1 and T2∗ relaxation times.

PubMed

Rieger, Benedikt; Zimmer, Fabian; Zapp, Jascha; Weingärtner, Sebastian; Schad, Lothar R

2017-11-01

To develop an implementation of the magnetic resonance fingerprinting (MRF) paradigm for quantitative imaging using echo-planar imaging (EPI) for simultaneous assessment of T 1 and T2∗. The proposed MRF method (MRF-EPI) is based on the acquisition of 160 gradient-spoiled EPI images with rapid, parallel-imaging accelerated, Cartesian readout and a measurement time of 10 s per slice. Contrast variation is induced using an initial inversion pulse, and varying the flip angles, echo times, and repetition times throughout the sequence. Joint quantification of T 1 and T2∗ is performed using dictionary matching with integrated B1+ correction. The quantification accuracy of the method was validated in phantom scans and in vivo in 6 healthy subjects. Joint T 1 and T2∗ parameter maps acquired with MRF-EPI in phantoms are in good agreement with reference measurements, showing deviations under 5% and 4% for T 1 and T2∗, respectively. In vivo baseline images were visually free of artifacts. In vivo relaxation times are in good agreement with gold-standard techniques (deviation T 1 : 4 ± 2%, T2∗: 4 ± 5%). The visual quality was comparable to the in vivo gold standard, despite substantially shortened scan times. The proposed MRF-EPI method provides fast and accurate T 1 and T2∗ quantification. This approach offers a rapid supplement to the non-Cartesian MRF portfolio, with potentially increased usability and robustness. Magn Reson Med 78:1724-1733, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

EURAMET key comparison no. EURAMET.T-K1: realisations of the ITS-90 from 2.6 K to 24.5561 K, using rhodium-iron resistance thermometers

NASA Astrophysics Data System (ADS)

Gaiser, Christof; Fellmuth, Bernd; Steur, Peter; Szmyrka-Grzebyk, Anna; Manuszkiewicz, Henryk; Lipinski, Leszek; Peruzzi, Andrea; Rusby, Richard; Head, David

2017-01-01

In the temperature range from 0.65 K to 24.5561 K, the ITS-90 is defined by specified vapour-pressure equations for 3He and 4He and interpolation equations for a constant-volume gas thermometer using 3He or 4He. The definitions are given in sections 3.1 and 3.2 of the ITS-90 text, and methods for realising the scale in this range are outlined in chapters 4 and 5 of the Guide to the Realization of the ITS-90 (formerly Supplementary Information for the ITS-90). Direct realisations of the ITS-90 by these methods require relatively sophisticated apparatus and time-consuming experiments, and consequently they are rarely carried out. The situation is acceptable in practice only because rhodium-iron resistance thermometers (RIRTs) are available that, once calibrated, are able to maintain their calibrations reliably for long periods of time. They are the practical thermometers on which realisations of the ITS-90 are most accurately maintained, disseminated and compared. The key comparison EURAMET.T-K1 is therefore a comparison of calibrated RIRTs. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Evolution of London penetration depth with scattering in single crystals of K1-xNaxFe2As2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, H; Tanatar, M A; Liu, Yong

2014-05-01

London penetration depth, λ(T), was measured in single crystals of K1-xNaxFe2As2, x=0 and 0.07, down to temperatures of 50 mK, ~Tc/50. Isovalent substitution of Na for K significantly increases impurity scattering, with ρ(Tc) rising from 0.2 to 2.2 μΩ cm, and leads to a suppression of Tc from 3.5 to 2.8 K. At the same time, a close to T-linear Δλ(T) in pure samples changes to almost T2 in the substituted samples. The behavior never becomes exponential as expected for the accidental nodes, as opposed to T2 dependence in superconductors with symmetry imposed line nodes. The superfluid density in themore » full temperature range follows a simple clean and dirty d-wave dependence, for pure and substituted samples, respectively. This result contradicts suggestions of multiband scenarios with strongly different gap structure on four sheets of the Fermi surface.« less

Kinetics of the R + NO2 reactions (R = i-C3H7, n-C3H7, s-C4H9, and t-C4H9) in the temperature range 201-489 K.

PubMed

Rissanen, Matti P; Arppe, Suula L; Eskola, Arkke J; Tammi, Matti M; Timonen, Raimo S

2010-04-15

The bimolecular rate coefficients of four alkyl radical reactions with NO(2) have been measured in direct time-resolved experiments. Reactions were studied under pseudo-first-order conditions in a temperature-controlled tubular flow reactor coupled to a laser photolysis/photoionization mass spectrometer (LP-PIMS). The measured reaction rate coefficients are independent of helium bath gas pressure within the experimental ranges covered and exhibit negative temperature dependence. For i-C(3)H(7) + NO(2) and t-C(4)H(9) + NO(2) reactions, the dependence of ordinate (logarithm of reaction rate coefficients) on abscissa (1/T or log(T)) was nonlinear. The obtained results (in cm(3) s(-1)) can be expressed by the following equations: k(n-C(3)H(7) + NO(2)) = ((4.34 +/- 0.08) x 10(-11)) (T/300 K)(-0.14+/-0.08) (203-473 K, 1-7 Torr), k(i-C(3)H(7) + NO(2)) = ((3.66 +/- 2.54) x 10(-12)) exp(656 +/- 201 K/T)(T/300 K)(1.26+/-0.68) (220-489 K, 1-11 Torr), k(s-C(4)H(9) + NO(2)) = ((4.99 +/- 0.16) x 10(-11))(T/300 K)(-1.74+/-0.12) (241-485 K, 2 - 12 Torr) and k(t-C(4)H(9) + NO(2)) = ((8.64 +/- 4.61) x 10(-12)) exp(413 +/- 154 K/T)(T/300 K)(0.51+/-0.55) (201-480 K, 2-11 Torr), where the uncertainties shown refer only to the 1 standard deviations obtained from the fitting procedure. The estimated overall uncertainty in the determined bimolecular rate coefficients is about +/-20%.

Potassium channel KCNH2 K897T polymorphism and cardiac repolarization during exercise test: The Finnish Cardiovascular Study.

PubMed

Koskela, J; Laiho, J; KäHönen, M; Rontu, R; Lehtinen, R; Viik, J; Niemi, M; Niemelä, K; Kööbi, T; Turjanmaa, V; Pörsti, I; Lehtimäki, T; Nieminen, T

2008-01-01

Cardiac repolarization is regulated, in part, by the KCNH2 gene, which encodes a rapidly activating component of the delayed rectifier potassium channel. The gene expresses a functional single nucleotide polymorphism, K897T, which changes the biophysical properties of the channel. The objective of this study was to evaluate whether this polymorphism influences two indices of repolarization--the QT interval and T-wave alternans (TWA)--during different phases of a physical exercise test. The cohort consisted of 1,975 patients undergoing an exercise test during which on-line electrocardiographic data were registered. Information on coronary risk factors and medication was recorded. The 2690A>C nucleotide variation in the KCNH2 gene corresponding to the K897T amino acid change was analysed after polymerase chain reaction with allele-specific TaqMan probes. Among all subjects, the QTc intervals did not differ between the three genotype groups (p> or =0.31, RANOVA). Women with the CC genotype tended to have longer QT intervals during the exercise test, but the difference was statistically significant only at rest (p = 0.011, ANOVA). This difference was also detected when the analysis was adjusted for several factors influencing the QT interval. No statistically significant effects of the K897T polymorphism on TWA were observed among all subjects (p = 0.16, RANOVA), nor in men and women separately. The K897T polymorphism of the KCNH2 gene may not be a major genetic determinant for the TWA, but the influence of the CC genotype on QT interval deserves further research among women.

Impact wave deposits provide new constraints on the location of the K/T boundary impact

NASA Technical Reports Server (NTRS)

Hildebrand, A. R.; Boynton, W. V.

1988-01-01

All available evidence is consistent with an impact into oceanic crust terminating the Cretaceous Period. Although much of this evidence is incompatible with an endogenic origin, some investigators still feel that a volcanic origin is possible for the Cretaceous/Tertiary (K/T) boundary clay layers. The commonly cited evidence for a large impact stems from delicate clay layers and their components and the impact site has not yet been found. Impact sites have been suggested all over the globe. The impact is felt to have occurred near North America by: the occurrence of a 2 cm thick ejecta layer only at North American locales, the global variation of shocked quartz grain sizes peaking in North America, the global variation of spinel compositions with most refractory compositions occurring in samples from the Pacific region and possibly uniquely severe plant extinctions in the North American region. The K/T boundary interval was investigated as preserved on the banks of the Brazos River, Texas. The K/T fireball and ejecta layers with associated geochemical anomalies were found interbedded with this sequence which apparently allows a temporal resolution 4 orders of magnitude greater than typical K/T boundary sections. A literature search reveals that such coarse deposits are widely preserved at the K/T boundary. Impact wave deposits have not been found elsewhere on the globe, suggesting the impact occurred between North and South America. The coarse deposits preserved in Deep Sea Drilling Project (DSDP) holes 151-3 suggest the impact occurred nearby. Subsequent tectonism has complicated the picture.

The Western North American Cretaceous-Tertiary (K-T) boundary interval and its content of shock-metamorphosed minerals: Implications concerning the K-T boundary impact-extinction theory

NASA Technical Reports Server (NTRS)

Izett, G. A.

1988-01-01

At 20 sites in the Raton Basin of Colorado and New Mexico, and at several other sites in Wyoming, Montana, and Canada, a pair of claystone units, an Ir abundance anomaly, and a concentration of shock-metamorphosed minerals mark the palynological K-T boundary. The K-T boundary claystone, which is composed of kaolinite and small amounts of illite/smectite mixed-layer clay, is similar in most respects to kaolinite tonstein layers in coal beds. At some, but not all, K-T boundary localities, the boundary claystone contains solid kaolinite and hollow and solid goyazite spherules, 0.05 to 1.2 mm in diameter. The upper unit, the K-T boundary impact layer, consists chiefly of kaolinite and various amounts of illite/smectite mixed-layer clay. The impact layer and boundary claystone are similar chemically, except that the former has slightly more Fe, K, Ba, Cr, Cu, Li, V, and Zn than the latter. The facts that the boundary claystone and impact layer contain anomalous amounts of Ir, comprise a stratigraphic couplet at Western North American sites, and form thin, discrete layers, similar to air-fall units (volcanic or impact), suggest that the claystone units are of impact origin. Significantly, the impact layer contains as much as 2 percent clastic mineral grains, about 30 percent of which contain multiple sets of shock lamellae. Only one such concentration of shocked minerals has been found near the K-T boundary. The type of K-T boundary shock-metamorphosed materials (quartzite and metaquartzite) in the impact layer and the lack of shock lamellae in quartz and feldspar of pumice lapilli and granitic xenoliths in air-fall pumice units of silicic tuffs, such as the Bishop Tuff, eliminate the possibility that the shock-metamorphosed minerals in the K-T impact layer are of volcanic origin. The global size distribution and abundance of shock-metamorphosed mineral grains suggest that the K-T impact occurred in North America.

Enhanced t -3/2 long-time tail for the stress-stress time correlation function

NASA Astrophysics Data System (ADS)

Evans, Denis J.

1980-01-01

Nonequilibrium molecular dynamics is used to calculate the spectrum of shear viscosity for a Lennard-Jones fluid. The calculated zero-frequency shear viscosity agrees well with experimental argon results for the two state points considered. The low-frequency behavior of shear viscosity is dominated by an ω 1/2 cusp. Analysis of the form of this cusp reveals that the stress-stress time correlation function exhibits a t -3/2 "long-time tail." It is shown that for the state points studied, the amplitude of this long-time tail is between 12 and 150 times larger than what has been predicted theoretically. If the low-frequency results are truly asymptotic, they imply that the cross and potential contributions to the Kubo-Green integrand for shear viscosity exhibit a t -3/2 long-time tail. This result contradicts the established theory of such processes.

One base pair change abolishes the T cell-restricted activity of a kB-like proto-enhancer element from the interleukin 2 promoter.

PubMed Central

Briegel, K; Hentsch, B; Pfeuffer, I; Serfling, E

1991-01-01

The inducible, T cell-specific enhancers of murine and human Interleukin 2 (Il-2) genes contain the kB-like sequence GGGATTTCACC as an essential cis-acting enhancer motif. When cloned in multiple copies this so-called TCEd (distal T cell element) acts as an inducible proto-enhancer element in E14 T lymphoma cells, but not in HeLa cells. In extracts of induced, Il-2 secreting El4 cells three individual protein factors bind to TCEd DNA. The binding of the most prominent factor, named TCF-1 (T cell factor 1), is correlated with the proto-enhancer activity of TCEd. TCF-1 consists of two polypeptides of about 50 kD and 105 kD; the former seems to be related to the 50 kD polypeptide of NF-kB. Purified NF-kB is also able to bind to the TCEd, but TCF-1 binds stronger than NF-kB to TCEd DNA. The conversion of the TCEd to a 'perfect' NF-kB binding site leads to a tighter binding of NF-kB to TCEd DNA and, as a functional consequence, to the activity of the 'converted' TCEd motifs in HeLa cells. Thus, the substitution of the underlined A residue to a C within the GGGATTTCACC motif abolishes its T cell-restricted activity and leads to its functioning in both El4 cells and HeLa cells. These results indicate that lymphocyte-specific factors binding to the TCEd are involved in the control of T cell specific-transcription of the Il-2 gene. Images PMID:1945879

k-t SENSE-accelerated Myocardial Perfusion MR Imaging at 3.0 Tesla - comparison with 1.5 Tesla

PubMed Central

Plein, Sven; Schwitter, Juerg; Suerder, Daniel; Greenwood, John P.; Boesiger, Peter; Kozerke, Sebastian

2008-01-01

Purpose To determine the feasibility and diagnostic accuracy of high spatial resolution myocardial perfusion MR at 3.0 Tesla using k-space and time domain undersampling with sensitivity encoding (k-t SENSE). Materials and Methods The study was reviewed and approved by the local ethic review board. k-t SENSE perfusion MR was performed at 1.5 Tesla and 3.0 Tesla (saturation recovery gradient echo pulse sequence, repetition time/echo time 3.0ms/1.0ms, flip angle 15°, 5x k-t SENSE acceleration, spatial resolution 1.3×1.3×10mm3). Fourteen volunteers were studied at rest and 37 patients during adenosine stress. In volunteers, comparison was also made with standard-resolution (2.5×2.5×10mm3) 2x SENSE perfusion MR at 3.0 Tesla. Image quality, artifact scores, signal-to-noise ratios (SNR) and contrast-enhancement ratios (CER) were derived. In patients, diagnostic accuracy of visual analysis to detect >50% diameter stenosis on quantitative coronary angiography was determined by receiver-operator-characteristics (ROC). Results In volunteers, image quality and artifact scores were similar for 3.0 Tesla and 1.5 Tesla, while SNR was higher (11.6 vs. 5.6) and CER lower (1.1 vs. 1.5, p=0.012) at 3.0 Tesla. Compared with standard-resolution perfusion MR, image quality was higher for k-t SENSE (3.6 vs. 3.1, p=0.04), endocardial dark rim artifacts were reduced (artifact thickness 1.6mm vs. 2.4mm, p<0.001) and CER similar. In patients, area under the ROC curve for detection of coronary stenosis was 0.89 and 0.80, p=0.21 for 3.0 Tesla and 1.5 Tesla, respectively. Conclusions k-t SENSE accelerated high-resolution perfusion MR at 3.0 Tesla is feasible with similar artifacts and diagnostic accuracy as at 1.5 Tesla. Compared with standard-resolution perfusion MR, image quality is improved and artifacts are reduced. PMID:18936311

In vivo estimation of transverse relaxation time constant (T2 ) of 17 human brain metabolites at 3T.

PubMed

Wyss, Patrik O; Bianchini, Claudio; Scheidegger, Milan; Giapitzakis, Ioannis A; Hock, Andreas; Fuchs, Alexander; Henning, Anke

2018-08-01

The transverse relaxation times T 2 of 17 metabolites in vivo at 3T is reported and region specific differences are addressed. An echo-time series protocol was applied to one, two, or three volumes of interest with different fraction of white and gray matter including a total number of 106 healthy volunteers and acquiring a total number of 128 spectra. The data were fitted with the 2D fitting tool ProFit2, which included individual line shape modeling for all metabolites and allowed the T 2 calculation of 28 moieties of 17 metabolites. The T 2 of 10 metabolites and their moieties have been reported for the first time. Region specific T 2 differences in white and gray matter enriched tissue occur in 16 of 17 metabolites examined including single resonance lines and coupled spin systems. The relaxation time T 2 is regions specific and has to be considered when applying tissue composition correction for internal water referencing. Magn Reson Med 80:452-461, 2018. © 2018 International Society for Magnetic Resonance in Medicine. © 2018 International Society for Magnetic Resonance in Medicine.

Harsh Corporal Punishment Is Associated With Increased T2 Relaxation Time in Dopamine-Rich Regions

PubMed Central

Sheu, Yi-Shin; Polcari, Ann; Anderson, Carl M.; Teicher, Martin H.

2010-01-01

Harsh corporal punishment (HCP) was defined as frequent parental administration of corporal punishment (CP) for discipline, with occasional use of objects such as straps, or paddles. CP is linked to increased risk for depression and substance abuse. We examine whether long-term exposure to HCP acts as sub-traumatic stressor that contributes to brain alterations, particularly in dopaminergic pathways, which may mediate their increased vulnerability to drug and alcohol abuse. Nineteen young adults who experienced early HCP but no other forms of maltreatment and twenty-three comparable controls were studied. T2 relaxation time (T2-RT) measurements were performed with an echo planar imaging TE stepping technique and T2 maps were calculated and analyzed voxel-by-voxel to locate regional T2-RT differences between groups. Previous studies indicated that T2-RT provides an indirect index of resting cerebral blood volume. Region of interest (ROI) analyses were also conducted in caudate, putamen, nucleus accumbens, anterior cingulate cortex, dorsolateral prefrontal cortex, thalamus, globus pallidus and cerebellar hemispheres. Voxel-based relaxometry showed that HCP was associated with increased T2-RT in right caudate and putamen. ROI analyses also revealed increased T2-RT in dorsolateral prefrontal cortex, substantia nigra, thalamus and accumbens but not globus pallidus or cerebellum. There were significant associations between T2-RT measures in dopamine target regions and use of drugs and alcohol, and memory performance. Alteration in the paramagnetic or hemodynamic properties of dopaminergic cell body and projection regions were observed in subjects with HCP, and these findings may relate to their increased risk for drug and alcohol abuse. PMID:20600981

Harsh corporal punishment is associated with increased T2 relaxation time in dopamine-rich regions.

PubMed

Sheu, Yi-Shin; Polcari, Ann; Anderson, Carl M; Teicher, Martin H

2010-11-01

Harsh corporal punishment (HCP) was defined as frequent parental administration of corporal punishment (CP) for discipline, with occasional use of objects such as straps, or paddles. CP is linked to increased risk for depression and substance abuse. We examine whether long-term exposure to HCP acts as sub-traumatic stressor that contributes to brain alterations, particularly in dopaminergic pathways, which may mediate their increased vulnerability to drug and alcohol abuse. Nineteen young adults who experienced early HCP but no other forms of maltreatment and twenty-three comparable controls were studied. T2 relaxation time (T2-RT) measurements were performed with an echo planar imaging TE stepping technique and T2 maps were calculated and analyzed voxel-by-voxel to locate regional T2-RT differences between groups. Previous studies indicated that T2-RT provides an indirect index of resting cerebral blood volume. Region of interest (ROI) analyses were also conducted in caudate, putamen, nucleus accumbens, anterior cingulate cortex, dorsolateral prefrontal cortex, thalamus, globus pallidus and cerebellar hemispheres. Voxel-based relaxometry showed that HCP was associated with increased T2-RT in right caudate and putamen. ROI analyses also revealed increased T2-RT in dorsolateral prefrontal cortex, substantia nigra, thalamus and accumbens but not globus pallidus or cerebellum. There were significant associations between T2-RT measures in dopamine target regions and use of drugs and alcohol, and memory performance. Alteration in the paramagnetic or hemodynamic properties of dopaminergic cell body and projection regions were observed in subjects with HCP, and these findings may relate to their increased risk for drug and alcohol abuse. Copyright 2010 Elsevier Inc. All rights reserved.

High transport current superconductivity in powder-in-tube Ba0.6K0.4Fe2As2 tapes at 27 T

NASA Astrophysics Data System (ADS)

Huang, He; Yao, Chao; Dong, Chiheng; Zhang, Xianping; Wang, Dongliang; Cheng, Zhe; Li, Jianqi; Awaji, Satoshi; Wen, Haihu; Ma, Yanwei

2018-01-01

The high upper critical field and low anisotropy of iron-based superconductors (IBS) make them particularly attractive for high-field applications, especially for the construction of next-generation nuclear magnetic resonance spectrometers, particle accelerators and high-field magnets. However, for practical use it is essential to make IBS materials into wire and tape conductors with sufficient current carrying capability, which is limited by misaligned grains inside the conductors. Here, based on a simple and low-cost powder-in-tube (PIT) method, we demonstrate a high transport critical current density (J c) reaching 1.5 × 105 A cm-2 (I c = 437 A) at 4.2 K and 10 T in Ba0.6K0.4Fe2As2 (Ba-122) tapes by texturing the grain orientation with optimized hot-press technique. The transport J c measured at 4.2 K under high magnetic fields of 27 T is still on the level of 5.5 × 104 A cm-2. Moreover, at 20 K and 5 T the transport J c is also as high as 5.4 × 104 A cm-2, showing a promising application potential in moderate temperature range which can be reached by liquid hydrogen or cryogenic cooling. All these J c values are the highest ever reported for IBS wires and tapes. The high-performance PIT Ba-122 tapes in this work suggest IBS to be a strong potential competitor of cuprate superconductors for the race of high-field applications in the future.

Spatial Distribution and Relationship of T1ρ and T2 Relaxation Times in Knee Cartilage With Osteoarthritis

PubMed Central

Li, Xiaojuan; Pai, Alex; Blumenkrantz, Gabrielle; Carballido-Gamio, Julio; Link, Thomas; Ma, Benjamin; Ries, Michael; Majumdar, Sharmila

2009-01-01

T1ρ and T2 relaxation time constants have been proposed to probe biochemical changes in osteoarthritic cartilage. This study aimed to evaluate the spatial correlation and distribution of T1ρ and T2 values in osteoarthritic cartilage. Ten patients with osteoarthritis (OA) and 10 controls were studied at 3T. The spatial correlation of T1ρ and T2 values was investigated using Z-scores. The spatial variation of T1ρ and T2 values in patellar cartilage was studied in different cartilage layers. The distribution of these relaxation time constants was measured using texture analysis parameters based on gray-level co-occurrence matrices (GLCM). The mean Z-scores for T1ρ and T2 values were significantly higher in OA patients vs. controls (P < 0.05). Regional correlation coefficients of T1ρ and T2 Z-scores showed a large range in both controls and OA patients (0.2– 0.7). OA patients had significantly greater GLCM contrast and entropy of T1ρ values than controls (P < 0.05). In summary, T1ρ and T2 values are not only increased but are also more heterogeneous in osteoarthritic cartilage. T1ρ and T2 values show different spatial distributions and may provide complementary information regarding cartilage degeneration in OA. PMID:19319904

Long range intermolecular interactions between the alkali diatomics Na2, K2, and NaK

NASA Astrophysics Data System (ADS)

Zemke, Warren T.; Byrd, Jason N.; Michels, H. Harvey; Montgomery, John A.; Stwalley, William C.

2010-06-01

Long range interactions between the ground state alkali diatomics Na2-Na2, K2-K2, Na2-K2, and NaK-NaK are examined. Interaction energies are first determined from ab initio calculations at the coupled-cluster with singles, doubles, and perturbative triples [CCSD(T)] level of theory, including counterpoise corrections. Long range energies calculated from diatomic molecular properties (polarizabilities and dipole and quadrupole moments) are then compared with the ab initio energies. A simple asymptotic model potential ELR=Eelec+Edisp+Eind is shown to accurately represent the intermolecular interactions for these systems at long range.

Rejecting Non-MIP-Like Tracks using Boosted Decision Trees with the T2K Pi-Zero Subdetector

NASA Astrophysics Data System (ADS)

Hogan, Matthew; Schwehr, Jacklyn; Cherdack, Daniel; Wilson, Robert; T2K Collaboration

2016-03-01

Tokai-to-Kamioka (T2K) is a long-baseline neutrino experiment with a narrow band energy spectrum peaked at 600 MeV. The Pi-Zero detector (PØD) is a plastic scintillator-based detector located in the off-axis near detector complex 280 meters from the beam origin. It is designed to constrain neutral-current induced π0 production background at the far detector using the water target which is interleaved between scintillator layers. A PØD-based measurement of charged-current (CC) single charged pion (1π+) production on water is being developed which will have expanded phase space coverage as compared to the previous analysis. The signal channel for this analysis, which for T2K is dominated by Δ production, is defined as events that produce a single muon, single charged pion, and any number of nucleons in the final state. The analysis will employ machine learning algorithms to enhance CC1π+ selection by studying topological observables that characterize signal well. Important observables for this analysis are those that discriminate a minimum ionizing particle (MIP) like a muon or pion from a proton at the T2K energies. This work describes the development of a discriminator using Boosted Decision Trees to reject non-MIP-like PØD tracks.

Measurement of the muon beam direction and muon flux for the T2K neutrino experiment

NASA Astrophysics Data System (ADS)

Suzuki, K.; Aoki, S.; Ariga, A.; Ariga, T.; Bay, F.; Bronner, C.; Ereditato, A.; Friend, M.; Hartz, M.; Hiraki, T.; Ichikawa, A. K.; Ishida, T.; Ishii, T.; Juget, F.; Kikawa, T.; Kobayashi, T.; Kubo, H.; Matsuoka, K.; Maruyama, T.; Minamino, A.; Murakami, A.; Nakadaira, T.; Nakaya, T.; Nakayoshi, K.; Otani, M.; Oyama, Y.; Patel, N.; Pistillo, C.; Sakashita, K.; Sekiguchi, T.; Suzuki, S. Y.; Tada, S.; Yamada, Y.; Yamamoto, K.; Yokoyama, M.

2015-05-01

The Tokai-to-Kamioka (T2K) neutrino experiment measures neutrino oscillations by using an almost pure muon neutrino beam produced at the J-PARC accelerator facility. The T2K muon monitor was installed to measure the direction and stability of the muon beam which is produced in conjunction with the muon neutrino beam. The systematic error in the muon beam direction measurement was estimated, using data and MC simulation, to be 0.28 mrad. During beam operation, the proton beam has been controlled using measurements from the muon monitor and the direction of the neutrino beam has been tuned to within 0.3 mrad with respect to the designed beam-axis. In order to understand the muon beam properties, measurement of the absolute muon yield at the muon monitor was conducted with an emulsion detector. The number of muon tracks was measured to be (4.06± 0.05± 0.10)× 10^4cm^{-2} normalized with 4× 10^{11} protons on target with 250 kA horn operation. The result is in agreement with the prediction, which is corrected based on hadron production data.

Role of the K(Ca)3.1 K+ channel in auricular lymph node CD4+ T-lymphocyte function of the delayed-type hypersensitivity model.

PubMed

Ohya, Susumu; Nakamura, Erina; Horiba, Sayuri; Kito, Hiroaki; Matsui, Miki; Yamamura, Hisao; Imaizumi, Yuji

2013-07-01

The intermediate-conductance Ca(2+)-activated K(+) channel (K(Ca)3.1) modulates the Ca(2+) response through the control of the membrane potential in the immune system. We investigated the role of K(Ca)3.1 on the pathogenesis of delayed-type hypersensitivity (DTH) in auricular lymph node (ALN) CD4(+) T-lymphocytes of oxazolone (Ox)-induced DTH model mice. The expression patterns of K(Ca)3.1 and its possible transcriptional regulators were compared among ALN T-lymphocytes of three groups [non-sensitized (Ox-/-), Ox-sensitized, but non-challenged (Ox+/-) and Ox-sensitized and -challenged (Ox+/+)] using real-time polymerase chain reaction, Western blotting and flow cytometry. KCa 3.1 activity was measured by whole-cell patch clamp and the voltage-sensitive dye imaging. The effects of K(Ca)3.1 blockade were examined by the administration of selective K(Ca)3.1 blockers. Significant up-regulation of K(Ca)3.1a was observed in CD4(+) T-lymphocytes of Ox+/- and Ox+/+, without any evident changes in the expression of the dominant-negative form, K(Ca)3.1b. Negatively correlated with this, the repressor element-1 silencing transcription factor (REST) was significantly down-regulated. Pharmacological blockade of K(Ca)3.1 resulted in an accumulation of the CD4(+) T-lymphocytes of Ox+/+ at the G0/G1 phase of the cell cycle, and also significantly recovered not only the pathogenesis of DTH, but also the changes in the K(Ca)3.1 expression and activity in the CD4(+) T-lymphocytes of Ox+/- and Ox+/+. The up-regulation of K(Ca)3.1a in conjunction with the down-regulation of REST may be involved in CD4(+) T-lymphocyte proliferation in the ALNs of DTH model mice; and K(Ca)3.1 may be an important target for therapeutic intervention in allergy diseases such as DTH. © 2013 The British Pharmacological Society.

The Cretaceous-Tertiary (K/T) impact: One or more source craters?

NASA Technical Reports Server (NTRS)

Koeberl, Christian

1992-01-01

The Cretaceous-Tertiary (K/T) boundary is marked by signs of a worldwide catastrophe, marking the demise of more than 50 percent of all living species. Ever since Alvarez et al. found an enrichment of IR and other siderophile elements in rocks marking the K/T boundary and interpreted it as the mark of a giant asteroid (or comet) impact, scientists have tried to understand the complexities of the K/T boundary event. The impact theory received a critical boost by the discovery of shocked minerals that have so far been found only in association with impact craters. One of the problems of the K/T impact theory was, and still is, the lack of an adequate large crater that is close to the maximum abundance of shocked grains in K/T boundary sections, which was found to occur in sections in Northern America. The recent discovery of impact glasses from a K/T section in Haiti has been crucial in establishing a connection with documented impact processes. The location of the impact-glass findings and the continental nature of detritus found in all K/T sections supports at least one impact site near the North American continent. The Manson Impact Structure is the largest recognized in the United States, 35 km in diameter, and has a radiometric age indistinguishable from that of the Cretaceous-Tertiary (K/T) boundary. Although the Manson structure may be too small, it may be considered at least one element of the events that led to the catastrophic loss of life and extinction of many species at that time. A second candidate for the K/T boundary crater is the Chicxulub structure, which was first suggested to be an impact crater more than a decade ago. Only recently, geophysical studies and petrological (as well as limited chemical) analyses have indicated that this buried structure may in fact be of impact origin. At present we can conclude that the Manson crater is the only confirmed crater of K/T age, but Chicxulub is becoming a strong contender; however, detailed geochemical

The Cretaceous-Tertiary (K/T) impact: One or more source craters?

NASA Astrophysics Data System (ADS)

Koeberl, Christian

The Cretaceous-Tertiary (K/T) boundary is marked by signs of a worldwide catastrophe, marking the demise of more than 50 percent of all living species. Ever since Alvarez et al. found an enrichment of IR and other siderophile elements in rocks marking the K/T boundary and interpreted it as the mark of a giant asteroid (or comet) impact, scientists have tried to understand the complexities of the K/T boundary event. The impact theory received a critical boost by the discovery of shocked minerals that have so far been found only in association with impact craters. One of the problems of the K/T impact theory was, and still is, the lack of an adequate large crater that is close to the maximum abundance of shocked grains in K/T boundary sections, which was found to occur in sections in Northern America. The recent discovery of impact glasses from a K/T section in Haiti has been crucial in establishing a connection with documented impact processes. The location of the impact-glass findings and the continental nature of detritus found in all K/T sections supports at least one impact site near the North American continent. The Manson Impact Structure is the largest recognized in the United States, 35 km in diameter, and has a radiometric age indistinguishable from that of the Cretaceous-Tertiary (K/T) boundary. Although the Manson structure may be too small, it may be considered at least one element of the events that led to the catastrophic loss of life and extinction of many species at that time. A second candidate for the K/T boundary crater is the Chicxulub structure, which was first suggested to be an impact crater more than a decade ago. Only recently, geophysical studies and petrological (as well as limited chemical) analyses have indicated that this buried structure may in fact be of impact origin. At present we can conclude that the Manson crater is the only confirmed crater of K/T age, but Chicxulub is becoming a strong contender; however, detailed geochemical

Long range intermolecular interactions between the alkali diatomics Na(2), K(2), and NaK.

PubMed

Zemke, Warren T; Byrd, Jason N; Michels, H Harvey; Montgomery, John A; Stwalley, William C

2010-06-28

Long range interactions between the ground state alkali diatomics Na(2)-Na(2), K(2)-K(2), Na(2)-K(2), and NaK-NaK are examined. Interaction energies are first determined from ab initio calculations at the coupled-cluster with singles, doubles, and perturbative triples [CCSD(T)] level of theory, including counterpoise corrections. Long range energies calculated from diatomic molecular properties (polarizabilities and dipole and quadrupole moments) are then compared with the ab initio energies. A simple asymptotic model potential E(LR)=E(elec)+E(disp)+E(ind) is shown to accurately represent the intermolecular interactions for these systems at long range.

The immediate effect of long-distance running on T2 and T2* relaxation times of articular cartilage of the knee in young healthy adults at 3.0 T MR imaging

PubMed Central

Welsch, Goetz H; Laqmani, Azien; Henes, Frank O; Kaul, Michael G; Schoen, Gerhard; Adam, Gerhard; Regier, Marc

2016-01-01

Objective: To quantitatively assess the immediate effect of long-distance running on T2 and T2* relaxation times of the articular cartilage of the knee at 3.0 T in young healthy adults. Methods: 30 healthy male adults (18–31 years) who perform sports at an amateur level underwent an initial MRI at 3.0 T with T2 weighted [16 echo times (TEs): 9.7–154.6 ms] and T2* weighted (24 TEs: 4.6–53.6 ms) relaxation measurements. Thereafter, all participants performed a 45-min run. After the run, all individuals were immediately re-examined. Data sets were post-processed using dedicated software (ImageJ; National Institute of Health, Bethesda, MD). 22 regions of interest were manually drawn in segmented areas of the femoral, tibial and patellar cartilage. For statistical evaluation, Pearson product–moment correlation coefficients and confidence intervals were computed. Results: Mean initial values were 35.7 ms for T2 and 25.1 ms for T2*. After the run, a significant decrease in the mean T2 and T2* relaxation times was observed for all segments in all participants. A mean decrease of relaxation time was observed for T2 with 4.6 ms (±3.6 ms) and for T2* with 3.6 ms (±5.1 ms) after running. Conclusion: A significant decrease could be observed in all cartilage segments for both biomarkers. Both quantitative techniques, T2 and T2*, seem to be valuable parameters in the evaluation of immediate changes in the cartilage ultrastructure after running. Advances in knowledge: This is the first direct comparison of immediate changes in T2 and T2* relaxation times after running in healthy adults. PMID:27336705

The immediate effect of long-distance running on T2 and T2* relaxation times of articular cartilage of the knee in young healthy adults at 3.0 T MR imaging.

PubMed

Behzadi, Cyrus; Welsch, Goetz H; Laqmani, Azien; Henes, Frank O; Kaul, Michael G; Schoen, Gerhard; Adam, Gerhard; Regier, Marc

2016-08-01

To quantitatively assess the immediate effect of long-distance running on T2 and T2* relaxation times of the articular cartilage of the knee at 3.0 T in young healthy adults. 30 healthy male adults (18-31 years) who perform sports at an amateur level underwent an initial MRI at 3.0 T with T2 weighted [16 echo times (TEs): 9.7-154.6 ms] and T2* weighted (24 TEs: 4.6-53.6 ms) relaxation measurements. Thereafter, all participants performed a 45-min run. After the run, all individuals were immediately re-examined. Data sets were post-processed using dedicated software (ImageJ; National Institute of Health, Bethesda, MD). 22 regions of interest were manually drawn in segmented areas of the femoral, tibial and patellar cartilage. For statistical evaluation, Pearson product-moment correlation coefficients and confidence intervals were computed. Mean initial values were 35.7 ms for T2 and 25.1 ms for T2*. After the run, a significant decrease in the mean T2 and T2* relaxation times was observed for all segments in all participants. A mean decrease of relaxation time was observed for T2 with 4.6 ms (±3.6 ms) and for T2* with 3.6 ms (±5.1 ms) after running. A significant decrease could be observed in all cartilage segments for both biomarkers. Both quantitative techniques, T2 and T2*, seem to be valuable parameters in the evaluation of immediate changes in the cartilage ultrastructure after running. This is the first direct comparison of immediate changes in T2 and T2* relaxation times after running in healthy adults.

Combined Analysis of Neutrino and Antineutrino Oscillations at T2K.

PubMed

Abe, K; Amey, J; Andreopoulos, C; Antonova, M; Aoki, S; Ariga, A; Autiero, D; Ban, S; Barbi, M; Barker, G J; Barr, G; Barry, C; Bartet-Friburg, P; Batkiewicz, M; Berardi, V; Berkman, S; Bhadra, S; Bienstock, S; Blondel, A; Bolognesi, S; Bordoni, S; Boyd, S B; Brailsford, D; Bravar, A; Bronner, C; Buizza Avanzini, M; Calland, R G; Campbell, T; Cao, S; Cartwright, S L; Catanesi, M G; Cervera, A; Checchia, C; Cherdack, D; Chikuma, N; Christodoulou, G; Clifton, A; Coleman, J; Collazuol, G; Coplowe, D; Cudd, A; Dabrowska, A; De Rosa, G; Dealtry, T; Denner, P F; Dennis, S R; Densham, C; Dewhurst, D; Di Lodovico, F; Di Luise, S; Dolan, S; Drapier, O; Duffy, K E; Dumarchez, J; Dziewiecki, M; Emery-Schrenk, S; Ereditato, A; Feusels, T; Finch, A J; Fiorentini, G A; Friend, M; Fujii, Y; Fukuda, D; Fukuda, Y; Galymov, V; Garcia, A; Giganti, C; Gizzarelli, F; Golan, T; Gonin, M; Hadley, D R; Haegel, L; Haigh, M D; Hansen, D; Harada, J; Hartz, M; Hasegawa, T; Hastings, N C; Hayashino, T; Hayato, Y; Helmer, R L; Hillairet, A; Hiraki, T; Hiramoto, A; Hirota, S; Hogan, M; Holeczek, J; Hosomi, F; Huang, K; Ichikawa, A K; Ikeda, M; Imber, J; Insler, J; Intonti, R A; Ishida, T; Ishii, T; Iwai, E; Iwamoto, K; Izmaylov, A; Jamieson, B; Jiang, M; Johnson, S; Jonsson, P; Jung, C K; Kabirnezhad, M; Kaboth, A C; Kajita, T; Kakuno, H; Kameda, J; Karlen, D; Katori, T; Kearns, E; Khabibullin, M; Khotjantsev, A; Kim, H; Kim, J; King, S; Kisiel, J; Knight, A; Knox, A; Kobayashi, T; Koch, L; Koga, T; Konaka, A; Kondo, K; Kormos, L L; Korzenev, A; Koshio, Y; Kowalik, K; Kropp, W; Kudenko, Y; Kurjata, R; Kutter, T; Lagoda, J; Lamont, I; Lamoureux, M; Larkin, E; Lasorak, P; Laveder, M; Lawe, M; Licciardi, M; Lindner, T; Liptak, Z J; Litchfield, R P; Li, X; Longhin, A; Lopez, J P; Lou, T; Ludovici, L; Lu, X; Magaletti, L; Mahn, K; Malek, M; Manly, S; Marino, A D; Martin, J F; Martins, P; Martynenko, S; Maruyama, T; Matveev, V; Mavrokoridis, K; Ma, W Y; Mazzucato, E; McCarthy, M; McCauley, N; McFarland, K S; McGrew, C; Mefodiev, A; Metelko, C; Mezzetto, M; Mijakowski, P; Minamino, A; Mineev, O; Mine, S; Missert, A; Miura, M; Moriyama, S; Mueller, Th A; Myslik, J; Nakadaira, T; Nakahata, M; Nakamura, K G; Nakamura, K; Nakamura, K D; Nakanishi, Y; Nakayama, S; Nakaya, T; Nakayoshi, K; Nantais, C; Nielsen, C; Nirkko, M; Nishikawa, K; Nishimura, Y; Novella, P; Nowak, J; O'Keeffe, H M; Okumura, K; Okusawa, T; Oryszczak, W; Oser, S M; Ovsyannikova, T; Owen, R A; Oyama, Y; Palladino, V; Palomino, J L; Paolone, V; Patel, N D; Paudyal, P; Pavin, M; Payne, D; Perkin, J D; Petrov, Y; Pickard, L; Pickering, L; Pinzon Guerra, E S; Pistillo, C; Popov, B; Posiadala-Zezula, M; Poutissou, J-M; Poutissou, R; Przewlocki, P; Quilain, B; Radermacher, T; Radicioni, E; Ratoff, P N; Ravonel, M; Rayner, M A; Redij, A; Reinherz-Aronis, E; Riccio, C; Rodrigues, P A; Rondio, E; Rossi, B; Roth, S; Rubbia, A; Rychter, A; Sakashita, K; Sánchez, F; Scantamburlo, E; Scholberg, K; Schwehr, J; Scott, M; Seiya, Y; Sekiguchi, T; Sekiya, H; Sgalaberna, D; Shah, R; Shaikhiev, A; Shaker, F; Shaw, D; Shiozawa, M; Shirahige, T; Short, S; Smy, M; Sobczyk, J T; Sobel, H; Sorel, M; Southwell, L; Steinmann, J; Stewart, T; Stowell, P; Suda, Y; Suvorov, S; Suzuki, A; Suzuki, S Y; Suzuki, Y; Tacik, R; Tada, M; Takeda, A; Takeuchi, Y; Tanaka, H K; Tanaka, H A; Terhorst, D; Terri, R; Thakore, T; Thompson, L F; Tobayama, S; Toki, W; Tomura, T; Touramanis, C; Tsukamoto, T; Tzanov, M; Uchida, Y; Vagins, M; Vallari, Z; Vasseur, G; Vladisavljevic, T; Wachala, T; Walter, C W; Wark, D; Wascko, M O; Weber, A; Wendell, R; Wilkes, R J; Wilking, M J; Wilkinson, C; Wilson, J R; Wilson, R J; Wret, C; Yamada, Y; Yamamoto, K; Yamamoto, M; Yanagisawa, C; Yano, T; Yen, S; Yershov, N; Yokoyama, M; Yoshida, K; Yuan, T; Yu, M; Zalewska, A; Zalipska, J; Zambelli, L; Zaremba, K; Ziembicki, M; Zimmerman, E D; Zito, M; Żmuda, J

2017-04-14

T2K reports its first results in the search for CP violation in neutrino oscillations using appearance and disappearance channels for neutrino- and antineutrino-mode beams. The data include all runs from January 2010 to May 2016 and comprise 7.482×10^{20} protons on target in neutrino mode, which yielded in the far detector 32 e-like and 135  μ-like events, and 7.471×10^{20} protons on target in antineutrino mode, which yielded 4 e-like and 66  μ-like events. Reactor measurements of sin^{2}2θ_{13} have been used as an additional constraint. The one-dimensional confidence interval at 90% for the phase δ_{CP} spans the range (-3.13, -0.39) for normal mass ordering. The CP conservation hypothesis (δ_{CP}=0, π) is excluded at 90% C.L.

Zodiacal Exoplanets in Time: Searching for Young Stars in K2

NASA Astrophysics Data System (ADS)

Morris, Nathan; Mann, Andrew W.

2017-06-01

Nearby young, open clusters such as the Hyades, Pleiades, and Praesepe provide an important reference point for the properties of stellar systems in general. In each cluster, all stars are of the same known age. As such, observations of planetary systems around these stars can be used to gain insight into the early stages of planetary system formation. K2, the revived Kepler mission, has provided a vast number of light curves for young stars in the and elsewhere in the K2 field. We aim to compute rotational periods from sunspot patterns for all K2 target stars and use gyrochronometric relationships derived from cluster stars to determine their ages. From there, we will search for planets around young stars outside the clusters with the ultimate goal of shedding light on how planets and planetary systems evolve with time.

Immunomodulatory effect of vitamin K2: Implications for bone health.

PubMed

Myneni, V D; Mezey, E

2018-03-01

In women with postmenopausal osteoporosis, vitamin K2 appears to decrease the incidence of hip, vertebral, and non-vertebral fractures. Women with postmenopausal osteoporosis have more circulating activated T cells compared with healthy postmenopausal and premenopausal women, but the effects of vitamin K2 on T cells have not been studied. In this study, we have looked at T-cell suppression by vitamin K2. Peripheral blood mononuclear cells (PBMCs) from three healthy donors were used. The PBMCs were stimulated with the mitogens phytohemagglutinin and concanavalin A, and T-cell proliferation was analyzed using flow cytometry based on carboxyfluorescein succinimidyl ester (CSFE) dye dilution. Vitamin K2 (60 and 100 μM) inhibited T-cell proliferation. Vitamin K1 at the same concentrations did not inhibit T-cell proliferation. Vitamin K2 has immunomodulatory activities. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

Dinosaur bone beds and mass mortality: Implications for the K-T extinction

NASA Technical Reports Server (NTRS)

Carpenter, Kenneth

1988-01-01

Mass accumulations of fossilized large terrestrial vertebrate skeletons (bone beds: BB) provide a test for K-T catastrophic extinction hypotheses. The two major factors contributing to BB formation are mode of death and sedimentation rate. Catastrophic mass mortality (CMM) is the sudden death of numerous individuals where species, age, health, gender, or social ranking offer no survivorship advantage. Noncatastrophic mass mortality (NCMM) occurs over time and is strongly influenced by species, age, or gender. In addition to cause of death, sedimentation rate is also important in BB formation. Models of BBs can be made. The CMM drops all individuals in their tracks, therefore, the BB should reflect the living population with respect to species, age, or gender. The NCMM results in monospecific BBs skewed in the direction of the less fit, usually the very young or very old, or towards a specific gender. The NCMM and AM BBs may become more similar the more spread out over time NCMM deaths occur because carcasses are widely scattered requiring hydraulic accumulation, and the greater time allows for more disarticulation and weathering. The CMM and NCMM BB appear to be dominated by social animals. Applying this and the characteristics of mortality patterns to the uppermost Cretaceous Hell Creek Formation indicates that only NCMM and AM BB occur. Furthermore, NCMM BB are rare in the upper third of the Hell Creek. Near the K-T boundary, only AM BB are known. The absence of CMM and NCMM BB appears to be real reflecting a decrease in population levels of some dinosaurs prior to the K-T event. The absence of CMM suggests that the K-T event did not lead to an instantaneous extinction of dinosaurs. Nor was there a protracted die-off due to an asteroid impact winter, because no NCMM BB are known at or near the K-T boundary.

Interpretation of f({epsilon}) measurements by T. Kimura, K. Akatsuka and K. Ohe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia, M.

1996-11-26

This note describes my analysis of the measurement of the electron energy distribution function in a DC glow discharge reported by T. Kimura, K. Akatsuka, and K. Ohe, in `Experimental and theoretical investigations of DC glow discharges in argon-nitrogen mixtures,`J. Phys. D: Appl. Phys. 27 (1994) 1664-1671. T. Kimura of the Department of Systems Engineering at the Nagoya Institute of Technology sent me this paper in 1994, as well as `Electron Energy Distribution Function in Neon-Nitrogen Mixture Positive Column,` T. Kimura, and K. Ohe, Jpn. J. Appl. Phys. Vol. 3 1, Part 1, No. 12A, December 1992, pp. 4051- 4052.more » I base my analysis on the data for a pure N{sub 2} discharge at p=1 torr in the 1994 paper. Figures 2 and 3 in that paper show a discrepancy between f({epsilon}) as measured by Langmuir probing and f({epsilon}) as calculated from E/N based on the measured axial field. Kimura et. al. explain their observation of hotter than expected electrons on superelastic collisions with vibrationally excited nitrogen. My fundamental point is that the radial field generated by ambipolar diffusion significantly augments E/N above the contribution from the axial field in this experiment, and creates a higher than expected radially averaged electron energy.« less

Twenty Years of Rad-Hard K14 SPAD in Space Projects

PubMed Central

Michálek, Vojtěch; Procházka, Ivan; Blažej, Josef

2015-01-01

During last two decades, several photon counting detectors have been developed in our laboratory. One of the most promising detector coming from our group silicon K14 Single Photon Avalanche Diode (SPAD) is presented with its valuable features and space applications. Based on the control electronics, it can be operated in both gated and non-gated mode. Although it was designed for photon counting detection, it can be employed for multiphoton detection as well. With respect to control electronics employed, the timing jitter can be as low as 20 ps RMS. Detection efficiency is about 40 % in range of 500 nm to 800 nm. The detector including gating and quenching circuitry has outstanding timing stability. Due to its radiation resistivity, the diode withstands 100 krad gamma ray dose without parameters degradation. Single photon detectors based on K14 SPAD were used for planetary altimeter and atmospheric lidar in MARS92/96 and Mars Surveyor ’98 space projects, respectively. Recent space applications of K14 SPAD comprises LIDAR and mainly time transfer between ground stations and artificial satellites. These include Laser Time Transfer, Time Transfer by Laser Link, and European Laser Timing projects. PMID:26213945

K-t GRAPPA-accelerated 4D flow MRI of liver hemodynamics: influence of different acceleration factors on qualitative and quantitative assessment of blood flow.

PubMed

Stankovic, Zoran; Fink, Jury; Collins, Jeremy D; Semaan, Edouard; Russe, Maximilian F; Carr, James C; Markl, Michael; Langer, Mathias; Jung, Bernd

2015-04-01

We sought to evaluate the feasibility of k-t parallel imaging for accelerated 4D flow MRI in the hepatic vascular system by investigating the impact of different acceleration factors. k-t GRAPPA accelerated 4D flow MRI of the liver vasculature was evaluated in 16 healthy volunteers at 3T with acceleration factors R = 3, R = 5, and R = 8 (2.0 × 2.5 × 2.4 mm(3), TR = 82 ms), and R = 5 (TR = 41 ms); GRAPPA R = 2 was used as the reference standard. Qualitative flow analysis included grading of 3D streamlines and time-resolved particle traces. Quantitative evaluation assessed velocities, net flow, and wall shear stress (WSS). Significant scan time savings were realized for all acceleration factors compared to standard GRAPPA R = 2 (21-71 %) (p < 0.001). Quantification of velocities and net flow offered similar results between k-t GRAPPA R = 3 and R = 5 compared to standard GRAPPA R = 2. Significantly increased leakage artifacts and noise were seen between standard GRAPPA R = 2 and k-t GRAPPA R = 8 (p < 0.001) with significant underestimation of peak velocities and WSS of up to 31 % in the hepatic arterial system (p <0.05). WSS was significantly underestimated up to 13 % in all vessels of the portal venous system for k-t GRAPPA R = 5, while significantly higher values were observed for the same acceleration with higher temporal resolution in two veins (p < 0.05). k-t acceleration of 4D flow MRI is feasible for liver hemodynamic assessment with acceleration factors R = 3 and R = 5 resulting in a scan time reduction of at least 40 % with similar quantitation of liver hemodynamics compared with GRAPPA R = 2.

Planet Hunters 2 in the K2 Era

NASA Astrophysics Data System (ADS)

Schwamb, Megan E.; Fischer, Debra; Boyajian, Tabetha S.; Giguere, Matthew J.; Ishikawa, Sascha; Lintott, Chris; Lynn, Stuart; Schmitt, Joseph; Snyder, Chris; Wang, Ji; Barclay, Thomas

2015-01-01

Planet Hunters (http://www.planethunters.org) is an online citizen science project enlisting hundreds of thousands of people to search for planet transits in the publicly released Kepler data. Volunteers mark the locations of visible transits in a web interface, with multiple independent classifiers reviewing a randomly selected ~30-day light curve segment. In September 2014, Planet Hunters entered a new phase. The project was relaunched with a brand new online classification interface and discussion tool built using the Zooniverse's (http://www.zooniverse.org) latest technology and web platform. The website has been optimized for the rapid discovery and identification of planet candidates in the light curves from K2, the two-wheeled ecliptic plane Kepler mission. We will give an overview of the new Planet Hunters classification interface and Round 2 review system in context of the K2 data. We will present the first results from the Planet Hunters 2 search of K2 Campaigns 0 and 1 including a summary of new planet candidates.

Ground roll attenuation using polarization analysis in the t-f-k domain

NASA Astrophysics Data System (ADS)

Wang, C.; Wang, Y.

2017-07-01

S waves travel slower than P waves and have a lower dominant frequency. Therefore, applying common techniques such as time-frequency filtering and f-k filtering to separate S waves from ground roll is difficult because ground roll is also characterized by slow velocity and low frequency. In this study, we present a method for attenuating ground roll using a polarization filtering method based on the t-f-k transform. We describe the particle motion of the waves by complex vector signals. Each pair of frequency components, whose frequencies have the same absolute value but different signs, of the complex signal indicate an elliptical or linear motion. The polarization parameters of the elliptical or linear motion are explicitly related to the two Fourier coefficients. We then extend these concepts to the t-f-k domain and propose a polarization filtering method for ground roll attenuation based on the t-f-k transform. The proposed approach can define automatically the time-varying reject zones on the f-k panel at different times as a function of the reciprocal ellipticity. Four attributes, time, frequency, apparent velocity and polarization are used to identify and extract the ground roll simultaneously. Thus, the ground roll and body waves can be separated as long as they are dissimilar in one of these attributes. We compare our method with commonly used filtering techniques by applying the methods to synthetic and real seismic data. The results indicate that our method can attenuate ground roll while preserving body waves more effectively than the other methods.

K-T impact(s): Continental, oceanic or both

NASA Technical Reports Server (NTRS)

Sharpton, V. L.; Schuraytz, B. C.; Murali, A. V.; Ryder, G.; Burke, K.

1988-01-01

Although geochemical and mineralogical evidence indicate that a major accretionary event occurred at the K-T boundary, no impact crater of suitable size and age was recognized. The 35 km Manson Structure, Iowa, was suggested recently as a possibility and Ar-40/Ar-39 determinations indicate that its formation age is indistinguishable from that of the K-T boundary. In order to test a possible association between Manson and the K-T boundary clay, the geochemistry and mineralogy of the K-T boundary clays at the Scollard Canyon section, Alberta and the Starkville South section, Colorado are compared with three dominant lithologies affected by the Manson impact: Proterozoic red clastics, underlying late-state granites, and gneisses. The chemical and mineralogical makeup of the Scollard Canyon boundary clay and its clastic constituents are presented, commenting on the implications for impact models. An impact into crystalline material of continental affinity appears to be required to explain the mineralogy and chemistry of the Scollard Canyon (and other Western N. American K-T sections). The low REE abundances of some K-T boundary layers are unusual but perhaps attempts should be made to understand the contributions of individual crustal components (e.g., carbonates, arkoses) as well as the potential for alteration involving these and other elements during and after impact-induced vaporization, before mantle excavation is invoked. If further studies confirm the results of published studies of marine boundary clays that indicate an oceanic target, attention must be paid to the possibility that multiple impacts occurred at the K-T boundary - one or more on the continents and one or more in the ocean.

Project W.A.T.E.R.

ERIC Educational Resources Information Center

EnviroTeach, 1992

1992-01-01

Introduces networking projects for studying rivers and water quality. Describes two projects in South Africa (Project W.A.T.E.R and SWAP) associated with the international network, Global Rivers Environmental Education Network. Discusses water test kits and educational material developed through Project W.A.T.E.R. (Water Awareness through…

[Imaging characteristics of PROPELLER T2-weighted imaging].

PubMed

Goto, Masami; Aoki, Shigeki; Hayashi, Naoto; Mori, Harushi; Watanabe, Yasushi; Ino, Kenji; Satake, Yoshirou; Nishida, Katuji; Sato, Haruo; Iida, Kyouhito; Mima, Kazuo; Ohtomo, Kuni

2004-11-01

As the PROPELLER sequence is a combination of the radial scan and fast-spin-echo (FSE) sequence, it can be considered an FSE sequence with a motion correlation. However, there are some differences between PROPELLER and FSE owing to differences in k-space trajectory. We clarified the imaging characteristics of PROPELLER T2-weighted imaging (T2WI) for different parameters in comparison with usual FSE T2WI. When the same parameters were used, PROPELLER T2WI showed a higher signal-to-noise ratio (SNR) and lower spatial resolution than usual FSE. Effective echo time (TE) changed with different echo train lengths (ETL) or different bandwidths on PROPELLER, and imaging contrast changed accordingly to be more effective.

Knee Cartilage Thickness, T1ρ and T2 Relaxation Time Are Related to Articular Cartilage Loading in Healthy Adults

PubMed Central

Van Rossom, Sam; Smith, Colin Robert; Zevenbergen, Lianne; Thelen, Darryl Gerard; Vanwanseele, Benedicte; Van Assche, Dieter; Jonkers, Ilse

2017-01-01

Cartilage is responsive to the loading imposed during cyclic routine activities. However, the local relation between cartilage in terms of thickness distribution and biochemical composition and the local contact pressure during walking has not been established. The objective of this study was to evaluate the relation between cartilage thickness, proteoglycan and collagen concentration in the knee joint and knee loading in terms of contact forces and pressure during walking. 3D gait analysis and MRI (3D-FSE, T1ρ relaxation time and T2 relaxation time sequence) of fifteen healthy subjects were acquired. Experimental gait data was processed using musculoskeletal modeling to calculate the contact forces, impulses and pressure distribution in the tibiofemoral joint. Correlates to local cartilage thickness and mean T1ρ and T2 relaxation times of the weight-bearing area of the femoral condyles were examined. Local thickness was significantly correlated with local pressure: medial thickness was correlated with medial condyle contact pressure and contact force, and lateral condyle thickness was correlated with lateral condyle contact pressure and contact force during stance. Furthermore, average T1ρ and T2 relaxation time correlated significantly with the peak contact forces and impulses. Increased T1ρ relaxation time correlated with increased shear loading, decreased T1ρ and T2 relaxation time correlated with increased compressive forces and pressures. Thicker cartilage was correlated with higher condylar loading during walking, suggesting that cartilage thickness is increased in those areas experiencing higher loading during a cyclic activity such as gait. Furthermore, the proteoglycan and collagen concentration and orientation derived from T1ρ and T2 relaxation measures were related to loading. PMID:28076431

Sub-kT/q Subthreshold-Slope Using Negative Capacitance in Low-Temperature Polycrystalline-Silicon Thin-Film Transistor

PubMed Central

Park, Jae Hyo; Jang, Gil Su; Kim, Hyung Yoon; Seok, Ki Hwan; Chae, Hee Jae; Lee, Sol Kyu; Joo, Seung Ki

2016-01-01

Realizing a low-temperature polycrystalline-silicon (LTPS) thin-film transistor (TFT) with sub-kT/q subthreshold slope (SS) is significantly important to the development of next generation active-matrix organic-light emitting diode displays. This is the first time a sub-kT/q SS (31.44 mV/dec) incorporated with a LTPS-TFT with polycrystalline-Pb(Zr,Ti)O3 (PZT)/ZrTiO4 (ZTO) gate dielectrics has been demonstrated. The sub-kT/q SS was observed in the weak inversion region at −0.5 V showing ultra-low operating voltage with the highest mobility (250.5 cm2/Vsec) reported so far. In addition, the reliability of DC negative bias stress, hot carrier stress and self-heating stress in LTPS-TFT with negative capacitance was investigated for the first time. It was found that the self-heating stress showed accelerated SS degradation due to the PZT Curie temperature. PMID:27098115

Neutrino Oscillations with the MINOS, MINOS+, T2K, and NOvA Experiments

DOE PAGES

Nakaya, Tsuyoshi; Plunkett, Robert K.

2016-01-18

Our paper discusses results and near-term prospects of the long-baseline neutrino experiments MINOS, MONOS+, T2K and NOvA. The non-zero value of the third neutrino mixing angle θ 13 allows experimental analysis in a manner which explicitly exhibits appearance and disappearance dependencies on additional parameters associated with mass-hierarchy, CP violation, and any non-maximal θ 23. Our current and near-future experiments begin the era of precision accelerator long-baseline measurements and lay the framework within which future experimental results will be interpreted.

Study of Bc→ψ (2 S )K , ηc(2 S )K , ψ (3770 )K decays with perturbative QCD approach

NASA Astrophysics Data System (ADS)

Duan, Feng-Bo; Yu, Xian-Qiao

2018-05-01

We study the Bc→ψ (2 S ) K , ηc(2 S ) K , ψ (3770 ) K decays with perturbative QCD approach based on kT factorization. The new orbitally excited charmonium distribution amplitudes ψ (1 3D1) based on the Schrödinger wave function of the n =1 , l =2 state for the harmonic-oscillator potential are employed. By using the corresponding distribution amplitudes, we calculate the branching ratio of Bc→ψ (2 S ) K , ηc(2 S ) K , ψ (3770 ) K decays and the form factors A0 ,1 ,2 and V for the transition Bc→ψ (1 3D1) . We obtain the branching ratio of both Bc→ψ (2 S ) K and Bc→ηc(2 S ) K are at the order of 10-5. The effects of two sets of the S-D mixing angle θ =-1 2 ° and θ =2 7 ° for the decay Bc→ψ (3770 ) K are studied first in this paper. Our calculations show that the branching ratio of the decay Bc→ψ (3770 ) K can be raised from the order of 10-6 to the order of 10-5 at the mixing angle θ =-1 2 ° , which can be tested by the running LHC-b experiments.

Crystal structures of K2[XSi5O12] (X = Fe2+, Co, Zn) and Rb2[XSi5O12] (X = Mn) leucites: comparison of monoclinic P21/c and Ia{\\overline 3}d polymorph structures and inverse relationship between tetrahedral cation (T = Si and X)-O bond distances and intertetrahedral T-O-T angles.

PubMed

Bell, Anthony M T; Henderson, C Michael B

2018-06-01

The leucite tectosilicate mineral analogues K 2 X 2+ Si 5 O 12 (X = Fe 2+ , Co, Zn) and Rb 2 X 2+ Si 5 O 12 (X = Mn) have been synthesized at elevated temperatures both dry at atmospheric pressure and at controlled water vapour pressure; for X = Co and Zn both dry and hydrothermally synthesized samples are available. Rietveld refinement of X-ray data for hydrothermal K 2 X 2+ Si 5 O 12 (X = Fe 2+ , Co, Zn) samples shows that they crystallize in the monoclinic space group P2 1 /c and have tetrahedral cations (Si and X) ordered onto distinct framework sites [cf. hydrothermal K 2 MgSi 5 O 12 ; Bell et al. (1994a), Acta Cryst. B50, 560-566]. Dry-synthesized K 2 X 2+ Si 5 O 12 (X = Co, Zn) and Rb 2 X 2+ Si 5 O 12 (X = Mn) samples crystallize in the cubic space group Ia{\\overline 3}d and with Si and X cations disordered in the tetrahedral framework sites as typified by dry K 2 MgSi 5 O 12 . Both structure types have tetrahedrally coordinated SiO 4 and XO 4 sharing corners to form a partially substituted silicate framework. Extraframework K + and Rb + cations occupy large channels in the framework. Structural data for the ordered samples show that mean tetrahedral Si-O and X-O bond lengths cover the ranges 1.60 Å (Si-O) to 2.24 Å (Fe 2+ -O) and show an inverse relationship with the intertetrahedral angles (T-O-T) which range from 144.7° (Si-O-Si) to 124.6° (Si-O-Fe 2+ ). For the compositions with both disordered and ordered tetrahedral cation structures (K 2 MgSi 5 O 12 , K 2 CoSi 5 O 12 , K 2 ZnSi 5 O 12 , Rb 2 MnSi 5 O 12 and Cs 2 CuSi 5 O 12 leucites) the disordered polymorphs always have larger unit-cell volumes, larger intertetrahedral T-O-T angles and smaller mean T-O distances than their isochemical ordered polymorphs. The ordered samples clearly have more flexible frameworks than the disordered structures which allow the former to undergo a greater degree of tetrahedral collapse around the interframework cavity cations. Multivariant linear regression has

T2 relaxation time is related to liver fibrosis severity

PubMed Central

Siqueira, Luiz; Uppal, Ritika; Alford, Jamu; Fuchs, Bryan C.; Yamada, Suguru; Tanabe, Kenneth; Chung, Raymond T.; Lauwers, Gregory; Chew, Michael L.; Boland, Giles W.; Sahani, Duhyant V.; Vangel, Mark; Hahn, Peter F.; Caravan, Peter

2016-01-01

Background The grading of liver fibrosis relies on liver biopsy. Imaging techniques, including elastography and relaxometric, techniques have had varying success in diagnosing moderate fibrosis. The goal of this study was to determine if there is a relationship between the T2-relaxation time of hepatic parenchyma and the histologic grade of liver fibrosis in patients with hepatitis C undergoing both routine, liver MRI and liver biopsy, and to validate our methodology with phantoms and in a rat model of liver fibrosis. Methods This study is composed of three parts: (I) 123 patients who underwent both routine, clinical liver MRI and biopsy within a 6-month period, between July 1999 and January 2010 were enrolled in a retrospective study. MR imaging was performed at 1.5 T using dual-echo turbo-spin echo equivalent pulse sequence. T2 relaxation time of liver parenchyma in patients was calculated by mono-exponential fit of a region of interest (ROI) within the right lobe correlating to histopathologic grading (Ishak 0–6) and routine serum liver inflammation [aspartate aminotransferase (AST) and alanine aminotransferase (ALT)]. Statistical comparison was performed using ordinary logistic and ordinal logistic regression and ANOVA comparing T2 to Ishak fibrosis without and using AST and ALT as covariates; (II) a phantom was prepared using serial dilutions of dextran coated magnetic iron oxide nanoparticles. T2 weighed imaging was performed by comparing a dual echo fast spin echo sequence to a Carr-Purcell-Meigboom-Gill (CPMG) multi-echo sequence at 1.5 T. Statistical comparison was performed using a paired t-test; (III) male Wistar rats receiving weekly intraperitoneal injections of phosphate buffer solution (PBS) control (n=4 rats); diethylnitrosamine (DEN) for either 5 (n=5 rats) or 8 weeks (n=4 rats) were MR imaged on a Bruker Pharmascan 4.7 T magnet with a home-built bird-cage coil. T2 was quantified by using a mono-exponential fitting algorithm on multi-slice multi

k-t accelerated aortic 4D flow MRI in under two minutes: Feasibility and impact of resolution, k-space sampling patterns, and respiratory navigator gating on hemodynamic measurements.

PubMed

Bollache, Emilie; Barker, Alex J; Dolan, Ryan Scott; Carr, James C; van Ooij, Pim; Ahmadian, Rouzbeh; Powell, Alex; Collins, Jeremy D; Geiger, Julia; Markl, Michael

2018-01-01

To assess the performance of highly accelerated free-breathing aortic four-dimensional (4D) flow MRI acquired in under 2 minutes compared to conventional respiratory gated 4D flow. Eight k-t accelerated nongated 4D flow MRI (parallel MRI with extended and averaged generalized autocalibrating partially parallel acquisition kernels [PEAK GRAPPA], R = 5, TRes = 67.2 ms) using four k y -k z Cartesian sampling patterns (linear, center-out, out-center-out, random) and two spatial resolutions (SRes1 = 3.5 × 2.3 × 2.6 mm 3 , SRes2 = 4.5 × 2.3 × 2.6 mm 3 ) were compared in vitro (aortic coarctation flow phantom) and in 10 healthy volunteers, to conventional 4D flow (16 mm-navigator acceptance window; R = 2; TRes = 39.2 ms; SRes = 3.2 × 2.3 × 2.4 mm 3 ). The best k-t accelerated approach was further assessed in 10 patients with aortic disease. The k-t accelerated in vitro aortic peak flow (Qmax), net flow (Qnet), and peak velocity (Vmax) were lower than conventional 4D flow indices by ≤4.7%, ≤ 11%, and ≤22%, respectively. In vivo k-t accelerated acquisitions were significantly shorter but showed a trend to lower image quality compared to conventional 4D flow. Hemodynamic indices for linear and out-center-out k-space samplings were in agreement with conventional 4D flow (Qmax ≤ 13%, Qnet ≤ 13%, Vmax ≤ 17%, P > 0.05). Aortic 4D flow MRI in under 2 minutes is feasible with moderate underestimation of flow indices. Differences in k-space sampling patterns suggest an opportunity to mitigate image artifacts by an optimal trade-off between scan time, acceleration, and k-space sampling. Magn Reson Med 79:195-207, 2018. © 2018 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

A PAX3 polymorphism (T315K) in a family exhibiting Waardenburg Syndrome type 2.

PubMed

Wang, C; Kim, E; Attaie, A; Smith, T N; Wilcox, E R; Lalwani, A K

1998-02-01

Waardenburg Syndrome (WS) is an autosomal-dominant disorder phenotypically characterized by sensorineural hearing loss and pigmentary disturbances. Presence of dystopia canthorum is indicative of WS type 1 and results from defects in the PAX3 gene, whereas normally located medial canthi is characteristic of type 2 WS (WS2) and is associated with defects in the microphthalmia-associated transcription factor (MIFT) gene. Here a neutral polymorphism is reported in the PAX3 gene (T315K) in a family with WS2. Copyright 1998 Academic Press Limited

Estimation of T2* Relaxation Time of Breast Cancer: Correlation with Clinical, Imaging and Pathological Features

PubMed Central

Seo, Mirinae; Jahng, Geon-Ho; Sohn, Yu-Mee; Rhee, Sun Jung; Oh, Jang-Hoon; Won, Kyu-Yeoun

2017-01-01

Objective The purpose of this study was to estimate the T2* relaxation time in breast cancer, and to evaluate the association between the T2* value with clinical-imaging-pathological features of breast cancer. Materials and Methods Between January 2011 and July 2013, 107 consecutive women with 107 breast cancers underwent multi-echo T2*-weighted imaging on a 3T clinical magnetic resonance imaging system. The Student's t test and one-way analysis of variance were used to compare the T2* values of cancer for different groups, based on the clinical-imaging-pathological features. In addition, multiple linear regression analysis was performed to find independent predictive factors associated with the T2* values. Results Of the 107 breast cancers, 92 were invasive and 15 were ductal carcinoma in situ (DCIS). The mean T2* value of invasive cancers was significantly longer than that of DCIS (p = 0.029). Signal intensity on T2-weighted imaging (T2WI) and histologic grade of invasive breast cancers showed significant correlation with T2* relaxation time in univariate and multivariate analysis. Breast cancer groups with higher signal intensity on T2WI showed longer T2* relaxation time (p = 0.005). Cancer groups with higher histologic grade showed longer T2* relaxation time (p = 0.017). Conclusion The T2* value is significantly longer in invasive cancer than in DCIS. In invasive cancers, T2* relaxation time is significantly longer in higher histologic grades and high signal intensity on T2WI. Based on these preliminary data, quantitative T2* mapping has the potential to be useful in the characterization of breast cancer. PMID:28096732

Rate Constant and RRKM Product Study for the Reaction Between CH3 and C2H3 at T = 298K

NASA Technical Reports Server (NTRS)

Thorn, R. Peyton, Jr.; Payne, Walter A., Jr.; Chillier, Xavier D. F.; Stief, Louis J.; Nesbitt, Fred L.; Tardy, D. C.

2000-01-01

The total rate constant k1 has been determined at P = 1 Torr nominal pressure (He) and at T = 298 K for the vinyl-methyl cross-radical reaction CH3 + C2H3 yields products. The measurements were performed in a discharge flow system coupled with collision-free sampling to a mass spectrometer operated at low electron energies. Vinyl and methyl radicals were generated by the reactions of F with C2H4 and CH4, respectively. The kinetic studies were performed by monitoring the decay of C2H3 with methyl in excess, 6 < |CH3|(sub 0)/|C2H3|(sub 0) < 21. The overall rate coefficient was determined to be k1(298 K) = (1.02 +/- 0.53)x10(exp -10) cubic cm/molecule/s with the quoted uncertainty representing total errors. Numerical modeling was required to correct for secondary vinyl consumption by reactions such as C2H3 + H and C2H3 + C2H3. The present result for k1 at T = 298 K is compared to two previous studies at high pressure (100-300 Torr He) and to a very recent study at low pressure (0.9-3.7 Torr He). Comparison is also made with the rate constant for the similar reaction CH3 + C2H5 and with a value for k1 estimated by the geometric mean rule employing values for k(CH3 + CH3) and k(C2H3 + C2H3). Qualitative product studies at T = 298 K and 200 K indicated formation of C3H6, C2H2, and C2H5 as products of the combination-stabilization, disproportionation, and combination-decomposition channels, respectively, of the CH3 + C2H3 reaction. We also observed the secondary C4H8 product of the subsequent reaction of C3H5 with excess CH3; this observation provides convincing evidence for the combination-decomposition channel yielding C3H5 + H. RRKM calculations with helium as the deactivator support the present and very recent experimental observations that allylic C-H bond rupture is an important path in the combination reaction. The pressure and temperature dependencies of the branching fractions are also predicted.

Regulated expression of the rat recombinant P2X(3) receptor in stably transfected CHO-K1 tTA cells.

PubMed

Lachnit, W G; Oglesby, I B; Gever, J R; Gever, M; Huang, C; Li, X C; Jin, H; McGivern, J G; Ford, A P

2000-07-03

In this report, the regulatable expression by tetracycline of the rat recombinant P2X(3) receptor in stably transfected Chinese hamster ovary (CHO-K1) expressing the tetracycline-controlled transactivator (tTA) is described. cDNA encoding the rat P2X(3)-receptor was subcloned into pTRE (a tetracycline-repressible expression vector) which was used to transfect stably CHO-K1 tTA cells. Using whole cell patch clamp techniques, 100 microM ATP evoked inward currents of 2.9+/-1.6 nA in transfected cells grown in the absence of tetracycline (tet-). The P2X(3) receptor protein was detectable by immunoblot as early as 24 h and protein expression levels continued to increase as much as 192 h following activation of tTA by the removal of the antibiotic. Saturation binding isotherms using [35S]ATP gamma S yielded a pK(d) of 8.2+/-0.1 and a B(max) of 31.9+/-3.5 pmol/mg protein in tet- cell membranes and a pK(d) of 8.1+/-0.1 and a B(max) of 5.8+/-0.8 pmol/mg protein in tet+ cell membranes. The agonist ligands 2MeSATP and alpha beta MeATP displaced the binding of [35S]ATP gamma S in tet- cell membranes with very high affinity, yielding pIC(50) values of 9.4+/-0.2 and 7.5+/-0. 2, respectively. In tet+ cell membrane, displacement of [35S]ATP gamma S by 2MeSATP and alpha beta MeATP was of much lower affinity (pIC(50) values of 7.8 and 6.2, respectively). ATP, ADP and UTP showed similar displacement of [35S]ATP gamma S binding in tet- and tet+ cell membranes. In other experiments, cytosolic Ca(2+) was monitored using the fluorescent indicator, fluo-3. Increases in cytosolic Ca(2+) were elicited by 100 nM alpha beta MeATP in tet- cells while no increases in cytosolic Ca(2+) were detected below 100 microM alpha beta MeATP in either tet+ cells or untransfected cells. These calcium responses to alpha beta MeATP had a pEC(50) of 6.7 and were transient, returning to baseline within 120 s. Suramin produced concentration-dependent, parallel, dextral shifts of E/[A] curves to alpha beta Me

The PAGES 2k Network, Phase 3: Introduction, Goals and Call for Participation

NASA Astrophysics Data System (ADS)

McGregor, Helen; Phipps, Steven; von Gunten, Lucien; Martrat, Belen; Linderholm, Lars; Abram, Nerilie; Bothe, Oliver; Neukom, Raphael; St. George, Scott; Evans, Michael; Kaufman, Darrell; Goosse, Hugues; Turney, Chris

2017-04-01

The past 2000 years (the "2k" interval) provides critical context for recent anthropogenic forcing of the climate, baseline information about Earth's natural climate variability, opportunities to improve the interpretation of proxy observations, and evaluation of climate models. The PAGES 2k Network (2008-2013 Phase 1; 2014-2016 Phase 2) built regional and global surface temperature reconstructions for terrestrial regions and the oceans, and used comparison with realistically forced simulations to identify mechanisms of climate variation on interannual to bicentennial time scales. The goals of Phase 3 (2017-2019), which launches in May 2017 at the PAGES Open Science Meeting, are to: 1) Further understand the mechanisms driving regional climate variability and change on interannual to centennial time scales (Theme: "Climate Variability, Modes and Mechanisms"); 2) Reduce uncertainties in the interpretation of observations imprinted in paleoclimatic archives by environmental sensors (Theme: "Methods and Uncertainties"); and 3) Identify and analyse the extent of agreement between reconstructions and climate model simulations (Theme: "Proxy and Model Understanding") Research will be organized as a linked network of well-defined projects and targeted manuscripts, identified and led by 2k members. The 2k projects will focus on specific scientific questions aligned with Phase 3 goals, rather than being defined along regional boundaries. An enduring element from earlier phases of PAGES 2k will be a culture of collegiality, transparency, and reciprocity. Phase 3 seeks to stimulate community based projects and facilitate collaboration of researchers from different regions and career stages, drawing on breadth and depth of the global PAGES 2k community; support end-to-end workflow transparency and open data and knowledge access; and develop collaborations with other research communities and engage with stakeholders. If you would like to participate in PAGES 2k Phase 3 or

Search for short baseline νe disappearance with the T2K near detector

NASA Astrophysics Data System (ADS)

Abe, K.; Adam, J.; Aihara, H.; Akiri, T.; Andreopoulos, C.; Aoki, S.; Ariga, A.; Assylbekov, S.; Autiero, D.; Barbi, M.; Barker, G. J.; Barr, G.; Bartet-Friburg, P.; Bass, M.; Batkiewicz, M.; Bay, F.; Berardi, V.; Berger, B. E.; Berkman, S.; Bhadra, S.; Blaszczyk, F. d. M.; Blondel, A.; Bojechko, C.; Bolognesi, S.; Bordoni, S.; Boyd, S. B.; Brailsford, D.; Bravar, A.; Bronner, C.; Buchanan, N.; Calland, R. G.; Caravaca Rodríguez, J.; Cartwright, S. L.; Castillo, R.; Catanesi, M. G.; Cervera, A.; Cherdack, D.; Christodoulou, G.; Clifton, A.; Coleman, J.; Coleman, S. J.; Collazuol, G.; Connolly, K.; Cremonesi, L.; Dabrowska, A.; Das, R.; Davis, S.; de Perio, P.; De Rosa, G.; Dealtry, T.; Dennis, S. R.; Densham, C.; Dewhurst, D.; Di Lodovico, F.; Di Luise, S.; Dolan, S.; Drapier, O.; Duboyski, T.; Duffy, K.; Dumarchez, J.; Dytman, S.; Dziewiecki, M.; Emery-Schrenk, S.; Ereditato, A.; Escudero, L.; Feusels, T.; Finch, A. J.; Fiorentini, G. A.; Friend, M.; Fujii, Y.; Fukuda, Y.; Furmanski, A. P.; Galymov, V.; Garcia, A.; Giffin, S.; Giganti, C.; Gilje, K.; Goeldi, D.; Golan, T.; Gonin, M.; Grant, N.; Gudin, D.; Hadley, D. R.; Haegel, L.; Haesler, A.; Haigh, M. D.; Hamilton, P.; Hansen, D.; Hara, T.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayashino, T.; Hayato, Y.; Hearty, C.; Helmer, R. L.; Hierholzer, M.; Hignight, J.; Hillairet, A.; Himmel, A.; Hiraki, T.; Hirota, S.; Holeczek, J.; Horikawa, S.; Huang, K.; Ichikawa, A. K.; Ieki, K.; Ieva, M.; Ikeda, M.; Imber, J.; Insler, J.; Irvine, T. J.; Ishida, T.; Ishii, T.; Iwai, E.; Iwamoto, K.; Iyogi, K.; Izmaylov, A.; Jacob, A.; Jamieson, B.; Jiang, M.; Johnson, S.; Jo, J. H.; Jonsson, P.; Jung, C. K.; Kabirnezhad, M.; Kaboth, A. C.; Kajita, T.; Kakuno, H.; Kameda, J.; Kanazawa, Y.; Karlen, D.; Karpikov, I.; Katori, T.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kielczewska, D.; Kikawa, T.; Kilinski, A.; Kim, J.; King, S.; Kisiel, J.; Kitching, P.; Kobayashi, T.; Koch, L.; Koga, T.; Kolaceke, A.; Konaka, A.; Kormos, L. L.; Korzenev, A.; Koshio, Y.; Kropp, W.; Kubo, H.; Kudenko, Y.; Kurjata, R.; Kutter, T.; Lagoda, J.; Lamont, I.; Larkin, E.; Laveder, M.; Lawe, M.; Lazos, M.; Lindner, T.; Lister, C.; Litchfield, R. P.; Longhin, A.; Lopez, J. P.; Ludovici, L.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Marino, A. D.; Marteau, J.; Martin, J. F.; Martins, P.; Martynenko, S.; Maruyama, T.; Matveev, V.; Mavrokoridis, K.; Mazzucato, E.; McCarthy, M.; McCauley, N.; McFarland, K. S.; McGrew, C.; Mefodiev, A.; Metelko, C.; Mezzetto, M.; Mijakowski, P.; Miller, C. A.; Minamino, A.; Mineev, O.; Missert, A.; Miura, M.; Moriyama, S.; Mueller, Th. A.; Murakami, A.; Murdoch, M.; Murphy, S.; Myslik, J.; Nakadaira, T.; Nakahata, M.; Nakamura, K. G.; Nakamura, K.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Nantais, C.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; Nowak, J.; O'Keeffe, H. M.; Ohta, R.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Ovsyannikova, T.; Owen, R. A.; Oyama, Y.; Palladino, V.; Palomino, J. L.; Paolone, V.; Payne, D.; Perevozchikov, O.; Perkin, J. D.; Petrov, Y.; Pickard, L.; Pinzon Guerra, E. S.; Pistillo, C.; Plonski, P.; Poplawska, E.; Popov, B.; Posiadala-Zezula, M.; Poutissou, J.-M.; Poutissou, R.; Przewlocki, P.; Quilain, B.; Radicioni, E.; Ratoff, P. N.; Ravonel, M.; Rayner, M. A. M.; Redij, A.; Reeves, M.; Reinherz-Aronis, E.; Riccio, C.; Rodrigues, P. A.; Rojas, P.; Rondio, E.; Roth, S.; Rubbia, A.; Ruterbories, D.; Rychter, A.; Sacco, R.; Sakashita, K.; Sánchez, F.; Sato, F.; Scantamburlo, E.; Scholberg, K.; Schoppmann, S.; Schwehr, J.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sgalaberna, D.; Shah, R.; Shaker, F.; Shaw, D.; Shiozawa, M.; Short, S.; Shustrov, Y.; Sinclair, P.; Smith, B.; Smy, M.; Sobczyk, J. T.; Sobel, H.; Sorel, M.; Southwell, L.; Stamoulis, P.; Steinmann, J.; Still, B.; Suda, Y.; Suzuki, A.; Suzuki, K.; Suzuki, S. Y.; Suzuki, Y.; Tacik, R.; Tada, M.; Takahashi, S.; Takeda, A.; Takeuchi, Y.; Tanaka, H. K.; Tanaka, H. A.; Tanaka, M. M.; Terhorst, D.; Terri, R.; Thompson, L. F.; Thorley, A.; Tobayama, S.; Toki, W.; Tomura, T.; Touramanis, C.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Vacheret, A.; Vagins, M.; Vasseur, G.; Wachala, T.; Wakamatsu, K.; Wallbank, M.; Walter, C. W.; Wark, D.; Warzycha, W.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilkes, R. J.; Wilking, M. J.; Wilkinson, C.; Williamson, Z.; Wilson, J. R.; Wilson, R. J.; Wongjirad, T.; Yamada, Y.; Yamamoto, K.; Yanagisawa, C.; Yano, T.; Yen, S.; Yershov, N.; Yokoyama, M.; Yoshida, K.; Yuan, T.; Yu, M.; Zalewska, A.; Zalipska, J.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Żmuda, J.; T2K Collaboration

2015-03-01

The T2K experiment has performed a search for νe disappearance due to sterile neutrinos using 5.9 ×1 020 protons on target for a baseline of 280 m in a neutrino beam peaked at about 500 MeV. A sample of νe CC interactions in the off-axis near detector has been selected with a purity of 63% and an efficiency of 26%. The p-value for the null hypothesis is 0.085 and the excluded region at 95% C.L. is approximately sin22 θee >0.3 for Δ meff2 >7 eV2/c4 .

Comparative Study of Multiplet Structures of Mn4+ in K2SiF6, K2GeF6, and K2TiF6 Based on First-Principles Configuration-Interaction Calculations

NASA Astrophysics Data System (ADS)

Novita, Mega; Ogasawara, Kazuyoshi

2012-02-01

We performed first-principles configuration-interaction calculations of multiplet energies for Mn4+ in K2SiF6, K2GeF6, and K2TiF6 crystals. The results indicate that corrections based on a single-electron calculation are effective for the prediction of 4A2 → 4T2 and 4A2 → 4T1a transition energies, while such corrections are not necessary for the prediction of the 4A2 → 2E transition energy. The cluster size dependence of the multiplet energies is small. However, the 4A2 → 2E transition energy is slightly improved by using larger clusters including K ions. The theoretical multiplet energies are improved further by considering the lattice relaxation effect. As a result, the characteristic multiplet energy shifts depending on the host crystal are well reproduced without using any empirical parameters. Although K2GeF6 and K2TiF6 have lower symmetry than K2SiF6, the results indicate that the variation of the multiplet energy is mainly determined by the Mn-F bond length.

New Analysis Of The Baptistina Asteroid Family: Implications For Its Link With The K/t Impactor

NASA Astrophysics Data System (ADS)

Delbo, Marco; Nesvorny, D.; Licandro, J.; Ali-Lagoa, V.

2012-10-01

The Baptistina Asteroid Family (BAF) is the result of the breakup of an asteroid roughly 100 million years ago. This family is the source of meteoroids and near-Earth asteroids and likely caused an asteroid shower of impactors on our Earth. Bottke et al. (2007) proposed a link between the BAF and the K/T impactor, based on the favorable timing, large probability of a terrestrial impact of one 10-km BAF asteroid, and the Sloan colors of the BAF members, indicating that the BAF may have composition consistent with the K/T impactor (CM2-type carbonaceous meteorite, as inferred from chromium studies at different K/T boundary sites; Alvarez et al. 1980, Kring et al. 2007). The relationship between the BAF and K/T impactor is now controversial. Masiero et al. (2011) found that the albedo of BAF family members is 0.15, significantly higher than expected for a dark carbonaceous parent body. Also, Reddy et al. (2011) reported the spectroscopic observations of (298) Baptistina and objects in the general neighborhood of the BAF, and suggested the BAF includes a mixture of spectroscopic types that is not very different from the background (mostly S-type asteroids in the background Flora family). Unfortunately, Reddy et al. observed only the large asteroids near (298) Baptistina, and not the K/T-impactor-size BAF members with D 10 km. Using WISE albedos, Sloan colors and newly obtained spectroscopic observations of BAF members, here we show that (1) the large objects in the BAF are mostly BAF interlopers, (2) that BAF has an homogeneous composition consistent with an X-type class. We discuss the implications of the link between the BAF and the K/T impactor.

Time Transfer by Laser Link - T2L2: Results of the First Year of Operation

DTIC Science & Technology

2009-11-01

transportable laser ranging system (FTLRS) based at Paris (Syrte). The availability on these sites of both a GPS and a TWSTFT station will allow a direct...on these two sites, of both a GPS and a TWSTFT station will also allow a direct comparison of T2L2 with RF time transfer techniques. T2L2...calibration of various existing radiofrequency time and frequency transfer systems like GPS or TWSTFT , and comparisons of cold-atom clocks at a level

Fires at the K/T boundary - Carbon at the Sumbar, Turkmenia, site

NASA Technical Reports Server (NTRS)

Wolbach, Wendy S.; Anders, Edward; Nazarov, Michael A.

1990-01-01

Results are reported on carbon analysis and on C and Ir correlations in samples from the marine K-T boundary site SM-4 at the Sumbar River in Turkmenia (USSR), which has the largest known Ir anomaly (580 ng/cq cm). In addition, the boundary clay is thick, and is undisturbed by bioturbation. Kerogen and delta-C-13 elemental carbon in the boundary clay were resolved using a Cr2O7(2-) oxidation method of Wolbach and Anders (1989). It was found that Ir and shocked quartz, both representing impact ejecta, rise sharply at the boundary, peak in the basal layer, and then decline. On the other hand, soot and total elemental C show a similar spike in the basal layer but then rise rather than fall, peking at 7 cm. Results indicate that fires at the SM-4 K-T boundary site started before the basal layer had settled, implying that ignition and spreading of major fires became possible at the time of or very soon after the meteorite impact.

K2 and K2*: efficient alignment-free sequence similarity measurement based on Kendall statistics.

PubMed

Lin, Jie; Adjeroh, Donald A; Jiang, Bing-Hua; Jiang, Yue

2018-05-15

Alignment-free sequence comparison methods can compute the pairwise similarity between a huge number of sequences much faster than sequence-alignment based methods. We propose a new non-parametric alignment-free sequence comparison method, called K2, based on the Kendall statistics. Comparing to the other state-of-the-art alignment-free comparison methods, K2 demonstrates competitive performance in generating the phylogenetic tree, in evaluating functionally related regulatory sequences, and in computing the edit distance (similarity/dissimilarity) between sequences. Furthermore, the K2 approach is much faster than the other methods. An improved method, K2*, is also proposed, which is able to determine the appropriate algorithmic parameter (length) automatically, without first considering different values. Comparative analysis with the state-of-the-art alignment-free sequence similarity methods demonstrates the superiority of the proposed approaches, especially with increasing sequence length, or increasing dataset sizes. The K2 and K2* approaches are implemented in the R language as a package and is freely available for open access (http://community.wvu.edu/daadjeroh/projects/K2/K2_1.0.tar.gz). yueljiang@163.com. Supplementary data are available at Bioinformatics online.

Geochemical evidences for two chondritic-like cometary or asteroidal impacts before and at the K/T boundary

NASA Technical Reports Server (NTRS)

Liu, Y.-G.; Schmitt, R. A.

1993-01-01

A number of geological and palaeontological evidences support multiple impacts of cometary showers within a short time (approximately 1-3 Ma) and their connection with mass extinctions. Observations include clustered crater ages, stratigraphic horizons of impact ejecta closely spaced in time, and evidence for stepwise mass extinctions spanning intervals of 1-3 Ma. For the K/T boundary, three candidates, Popigai, Manson, and Yucatan, have been proposed as impact craters. Two distinct strata at the K/T boundary in western North America have been interpreted as evidence for two sequential impacts. If multiple impacts occurred within a time span of about 1 Ma then multiple Ir enrichments should be observed. DSDP Hole 577B on the Shatsky Plateau in the northern Pacific at K/T time is the first site. Samples contain approximately greater than 97 percent CaCO3, which exhibit clear chemical signals associated with asteroidal/cometary impact. Ir, Fe, and Cr data are presented. From the Th-normalized data, two satellite peaks below the major peak at 78 cm and 81 cm of 577B-1-4 are clearly shown. The major Ir peak (K/T boundary) is at 72 cm. Fe and Cr, from C1-like impactor ejecta fallout, also show two peaks at the same positions. For hole 738C on the southern Kerguelen Plateau, Ir values reach a peak concentration of 18 ppb in the clay layer at 96.0-96.2 cm in section 20R-5, and gradually tail off. In the sample 115 cm above the boundary, Ir concentrations have still not reached background levels. From the Ir peak downward to the lowermost sample analyzed at 102 cm, the Ir concentration is still as high as 1.7 ppb. From the Th-normalized data, we observe a small Ir/Th peak at 100-101 cm. Though this peak is within the error margin, the trend is clear. Fe and Cr exhibit the same pattern. The third case is Hole 690C on the Queen Maud Ridge. Again, the Ir/Th plot indicates the strong possibility of satellite peaks at approximately 52 cm. The main peak is at 39-40 cm. For the

The K2-HERMES Survey. I. Planet-candidate Properties from K2 Campaigns 1–3

NASA Astrophysics Data System (ADS)

Wittenmyer, Robert A.; Sharma, Sanjib; Stello, Dennis; Buder, Sven; Kos, Janez; Asplund, Martin; Duong, Ly; Lin, Jane; Lind, Karin; Ness, Melissa; Zwitter, Tomaz; Horner, Jonathan; Clark, Jake; Kane, Stephen R.; Huber, Daniel; Bland-Hawthorn, Joss; Casey, Andrew R.; De Silva, Gayandhi M.; D’Orazi, Valentina; Freeman, Ken; Martell, Sarah; Simpson, Jeffrey D.; Zucker, Daniel B.; Anguiano, Borja; Casagrande, Luca; Esdaile, James; Hon, Marc; Ireland, Michael; Kafle, Prajwal R.; Khanna, Shourya; Marshall, J. P.; Saddon, Mohd Hafiz Mohd; Traven, Gregor; Wright, Duncan

2018-02-01

Accurate and precise radius estimates of transiting exoplanets are critical for understanding their compositions and formation mechanisms. To know the planet, we must know the host star in as much detail as possible. We present first results from the K2-HERMES project, which uses the HERMES multi-object spectrograph on the Anglo-Australian Telescope to obtain R ∼ 28000 spectra of up to 360 stars in one exposure. This ongoing project aims to derive self-consistent spectroscopic parameters for about half of K2 target stars. We present complete stellar parameters and isochrone-derived masses and radii for 46 stars hosting 57 K2 candidate planets in Campaigns 1–3. Our revised host-star radii cast severe doubt on three candidate planets: EPIC 201407812.01, EPIC 203070421.01, and EPIC 202843107.01, all of which now have inferred radii well in excess of the largest known inflated Jovian planets.

Combined Analysis of Neutrino and Antineutrino Oscillations at T2K

NASA Astrophysics Data System (ADS)

Abe, K.; Amey, J.; Andreopoulos, C.; Antonova, M.; Aoki, S.; Ariga, A.; Autiero, D.; Ban, S.; Barbi, M.; Barker, G. J.; Barr, G.; Barry, C.; Bartet-Friburg, P.; Batkiewicz, M.; Berardi, V.; Berkman, S.; Bhadra, S.; Bienstock, S.; Blondel, A.; Bolognesi, S.; Bordoni, S.; Boyd, S. B.; Brailsford, D.; Bravar, A.; Bronner, C.; Buizza Avanzini, M.; Calland, R. G.; Campbell, T.; Cao, S.; Cartwright, S. L.; Catanesi, M. G.; Cervera, A.; Checchia, C.; Cherdack, D.; Chikuma, N.; Christodoulou, G.; Clifton, A.; Coleman, J.; Collazuol, G.; Coplowe, D.; Cudd, A.; Dabrowska, A.; De Rosa, G.; Dealtry, T.; Denner, P. F.; Dennis, S. R.; Densham, C.; Dewhurst, D.; Di Lodovico, F.; Di Luise, S.; Dolan, S.; Drapier, O.; Duffy, K. E.; Dumarchez, J.; Dziewiecki, M.; Emery-Schrenk, S.; Ereditato, A.; Feusels, T.; Finch, A. J.; Fiorentini, G. A.; Friend, M.; Fujii, Y.; Fukuda, D.; Fukuda, Y.; Galymov, V.; Garcia, A.; Giganti, C.; Gizzarelli, F.; Golan, T.; Gonin, M.; Hadley, D. R.; Haegel, L.; Haigh, M. D.; Hansen, D.; Harada, J.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayashino, T.; Hayato, Y.; Helmer, R. L.; Hillairet, A.; Hiraki, T.; Hiramoto, A.; Hirota, S.; Hogan, M.; Holeczek, J.; Hosomi, F.; Huang, K.; Ichikawa, A. K.; Ikeda, M.; Imber, J.; Insler, J.; Intonti, R. A.; Ishida, T.; Ishii, T.; Iwai, E.; Iwamoto, K.; Izmaylov, A.; Jamieson, B.; Jiang, M.; Johnson, S.; Jonsson, P.; Jung, C. K.; Kabirnezhad, M.; Kaboth, A. C.; Kajita, T.; Kakuno, H.; Kameda, J.; Karlen, D.; Katori, T.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kim, H.; Kim, J.; King, S.; Kisiel, J.; Knight, A.; Knox, A.; Kobayashi, T.; Koch, L.; Koga, T.; Konaka, A.; Kondo, K.; Kormos, L. L.; Korzenev, A.; Koshio, Y.; Kowalik, K.; Kropp, W.; Kudenko, Y.; Kurjata, R.; Kutter, T.; Lagoda, J.; Lamont, I.; Lamoureux, M.; Larkin, E.; Lasorak, P.; Laveder, M.; Lawe, M.; Licciardi, M.; Lindner, T.; Liptak, Z. J.; Litchfield, R. P.; Li, X.; Longhin, A.; Lopez, J. P.; Lou, T.; Ludovici, L.; Lu, X.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Marino, A. D.; Martin, J. F.; Martins, P.; Martynenko, S.; Maruyama, T.; Matveev, V.; Mavrokoridis, K.; Ma, W. Y.; Mazzucato, E.; McCarthy, M.; McCauley, N.; McFarland, K. S.; McGrew, C.; Mefodiev, A.; Metelko, C.; Mezzetto, M.; Mijakowski, P.; Minamino, A.; Mineev, O.; Mine, S.; Missert, A.; Miura, M.; Moriyama, S.; Mueller, Th. A.; Myslik, J.; Nakadaira, T.; Nakahata, M.; Nakamura, K. G.; Nakamura, K.; Nakamura, K. D.; Nakanishi, Y.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Nantais, C.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; Novella, P.; Nowak, J.; O'Keeffe, H. M.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Ovsyannikova, T.; Owen, R. A.; Oyama, Y.; Palladino, V.; Palomino, J. L.; Paolone, V.; Patel, N. D.; Paudyal, P.; Pavin, M.; Payne, D.; Perkin, J. D.; Petrov, Y.; Pickard, L.; Pickering, L.; Pinzon Guerra, E. S.; Pistillo, C.; Popov, B.; Posiadala-Zezula, M.; Poutissou, J.-M.; Poutissou, R.; Przewlocki, P.; Quilain, B.; Radermacher, T.; Radicioni, E.; Ratoff, P. N.; Ravonel, M.; Rayner, M. A.; Redij, A.; Reinherz-Aronis, E.; Riccio, C.; Rodrigues, P. A.; Rondio, E.; Rossi, B.; Roth, S.; Rubbia, A.; Rychter, A.; Sakashita, K.; Sánchez, F.; Scantamburlo, E.; Scholberg, K.; Schwehr, J.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sgalaberna, D.; Shah, R.; Shaikhiev, A.; Shaker, F.; Shaw, D.; Shiozawa, M.; Shirahige, T.; Short, S.; Smy, M.; Sobczyk, J. T.; Sobel, H.; Sorel, M.; Southwell, L.; Steinmann, J.; Stewart, T.; Stowell, P.; Suda, Y.; Suvorov, S.; Suzuki, A.; Suzuki, S. Y.; Suzuki, Y.; Tacik, R.; Tada, M.; Takeda, A.; Takeuchi, Y.; Tanaka, H. K.; Tanaka, H. A.; Terhorst, D.; Terri, R.; Thakore, T.; Thompson, L. F.; Tobayama, S.; Toki, W.; Tomura, T.; Touramanis, C.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Vagins, M.; Vallari, Z.; Vasseur, G.; Vladisavljevic, T.; Wachala, T.; Walter, C. W.; Wark, D.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilkes, R. J.; Wilking, M. J.; Wilkinson, C.; Wilson, J. R.; Wilson, R. J.; Wret, C.; Yamada, Y.; Yamamoto, K.; Yamamoto, M.; Yanagisawa, C.; Yano, T.; Yen, S.; Yershov, N.; Yokoyama, M.; Yoshida, K.; Yuan, T.; Yu, M.; Zalewska, A.; Zalipska, J.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Żmuda, J.; T2K Collaboration

2017-04-01

T2K reports its first results in the search for C P violation in neutrino oscillations using appearance and disappearance channels for neutrino- and antineutrino-mode beams. The data include all runs from January 2010 to May 2016 and comprise 7.482 ×1 020 protons on target in neutrino mode, which yielded in the far detector 32 e -like and 135 μ -like events, and 7.471 ×1 020 protons on target in antineutrino mode, which yielded 4 e -like and 66 μ -like events. Reactor measurements of sin22 θ13 have been used as an additional constraint. The one-dimensional confidence interval at 90% for the phase δC P spans the range (-3.13 , -0.39 ) for normal mass ordering. The C P conservation hypothesis (δC P=0 , π ) is excluded at 90% C.L.

Hadro-Production Measurements to Characterize the T2K Neutrino Flux with the NA61 Experiment at the CERN SPS

NASA Astrophysics Data System (ADS)

Bravar, Alessandro

2010-03-01

As the intensity of neutrino beams produced at accelerators increases, the systematic errors due to the poor characterization of the neutrino flux become a limiting factor for high precision neutrino oscillation experiments like T2K. This limitation comes mainly from the poor knowledge of production cross sections for pions and kaons at the same energy and over the same phase-space yielding these neutrino beams. Therefore new hadro-production measurements are mandatory. The NA61/SHINE is a large acceptance hadron spectrometer at the CERN-SPS designed for the study of the hadronic final states produced in interactions of various beam particles (protons, π's, and heavy ions) with a variety of fixed targets at the SPS energies. Ongoing measurements with the NA61 detector for characterizing the neutrino beam of the T2K experiment at J-PARC are introduced. These measurements are performed using a 30 GeV proton beam impinging on carbon targets of different lengths, including a replica of the T2K target. The performance of the NA61 detector and preliminary NA61 measurements from the 2007 run are presented.

ν{sub μ} CCπ° reaction in the tracker of the ND280 detector in the T2K experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Batkiewicz, Marcela

A good knowledge of both inclusive and exclusive neutrino interaction cross sections is one of the key issues for a precise determination of the neutrino oscillation parameters in the T2K experiment. These studies are performed at the near detector (ND280). Its central tracker part equipped with a water target is used, among others, to study the ν{sub μ}CCπ° reaction. At the energies of the T2K neutrino beam its contribution to the total cross section is relatively large, so the reaction is a potential source of the background for the quasi-elastic ν{sub μ}CC reaction. Two different production mechanisms contribute to ν{submore » μ}CCπ°: single pion resonance production and Deep Inelastic Scattering (DIS). In addition, Final State Interactions (FSI) have to be considered. Thus, the analysis of the ν{sub μ}CCπ° reaction aims also at a better tuning of the Monte Carlo (MC) models used to describe neutrino interactions in T2K. This paper describes selection criteria leading to the determination of the inclusive and exclusive cross sections for the π° production in the ν{sub μ}CC interactions.« less

Diagnostic value of T1 and T2 * relaxation times and off-resonance saturation effects in the evaluation of Achilles tendinopathy by MRI at 3T.

PubMed

Grosse, Ulrich; Syha, Roland; Hein, Tobias; Gatidis, Sergios; Grözinger, Gerd; Schabel, Christoph; Martirosian, Petros; Schick, Fritz; Springer, Fabian

2015-04-01

To evaluate and compare the diagnostic value of T1 , T2 * relaxation times and off-resonance saturation ratios (OSR) in healthy controls and patients with different clinical and morphological stages of Achilles tendinopathy. Forty-two healthy Achilles tendons and 34 tendons of 17 patients with symptomatic and asymptomatic tendinopathy were investigated clinically with conventional magnetic resonance imaging (MRI) sequences on a 3T whole-body MR scanner and a dynamic ultrasound examination. In addition, T1 and T2 * relaxation times were assessed using an ultrashort echo time (UTE) imaging sequence with flip angle and echo time variation. For the calculation of OSR values a Gaussian off-resonance saturation pulse (frequency offset: 750-5000 Hz) was used. The diagnostic value of the derived MR values was assessed and compared using receiver operating characteristic (ROC) curves. ROC curves demonstrate the highest overall test performance for OSR values at 2000 Hz off-resonance in differentiating slightly (OSR-2000 [AUC: 0.930] > T2 * [AUC: 0.884] > T1 [AUC: 0.737]) and more severe pathologically altered tendon areas (OSR-2000 [AUC: 0.964] > T2 * [AUC: 0.917] > T1 [AUC: 0.819]) from healthy ones. OSR values at a frequency offset of 2000 Hz demonstrated a better sensitivity and specificity for detecting mild and severe stages of tendinopathy compared to T2 * and particularly when compared to T1 relaxation times. © 2014 Wiley Periodicals, Inc.

Deccan volcanism and K-T boundary signatures

NASA Technical Reports Server (NTRS)

Murali, A. V.; Schuraytz, B. C.; Parekh, P. P.

1988-01-01

The Deccan Traps in the Indian subcontinent represent one of the most extensive flood basalt provinces in the world. These basalts occur mainly as flat-lying, subaerially erupted tholeiitic lava flows, some of which are traceable for distances of more than 100 km. Offshore drilling and geophysical surveys indicate that a part of the Deccan subsided or was downfaulted to the west beneath the Arabian Sea. The presence of 1 to 5 m thick intertrappean sediments deposited by lakes and rivers indicates periods of quiescence between eruptions. The occurrence of numerous red bole beds among the flows suggests intense weathering of flow tops between eruptive intervals. Although the causative relationship of the Cretaceous-Tertiary (K-T) biotic extinctions to Deccan volcanism is debatable, the fact that the main Deccan eruptions straddle the K-T event appears beyond doubt from the recent Ar-40/Ar-39 ages of various Deccan flows. This temporal relationship of the K-T event with Deccan volcanism makes the petrochemical signatures of the entire Deccan sequence (basalt flows, intercalated intertrappean sediments, infratrappean Lameta beds (with dinosaur fossils), and the bole beds) pertinent to studies of the K-T event. The results of ongoing study is presented.

Patellar cartilage lesions: comparison of magnetic resonance imaging and T2 relaxation-time mapping.

PubMed

Hannila, I; Nieminen, M T; Rauvala, E; Tervonen, O; Ojala, R

2007-05-01

To evaluate the detection and the size of focal patellar cartilage lesions in T2 mapping as compared to standard clinical magnetic resonance imaging (MRI) at 1.5T. Fifty-five consecutive clinical patients referred to knee MRI were imaged both with a standard knee MRI protocol (proton-density-weighted sagittal and axial series, T2-weighted sagittal and coronal series, and T1-weighted coronal series) and with an axial multislice multi-echo spin-echo measurement to determine the T2 relaxation time of the patellar cartilage. MR images and T2 maps of patellar cartilage were evaluated for focal lesions. The lesions were evaluated for lesion width (mm), lesion depth (1/3, 2/3, or 3/3 of cartilage thickness), and T2 value (20-40 ms, 40-60 ms, or 60-80 ms) based on visual evaluation. Altogether, 36 focal patellar cartilage lesions were detected from 20 human subjects (11 male, nine female, mean age 40+/-15 years). Twenty-eight lesions were detected both on MRI and T2 maps, while eight lesions were only visible on T2 maps. Cartilage lesions were significantly wider (P = 0.001) and thicker (P<0.001) on T2 maps as compared to standard knee MRI. Most lesions 27 had moderately (T2 40-60 ms) increased T2 values, while two lesions had slightly (T2 20-40 ms) and seven lesions remarkably (T2 60-80 ms) increased T2 relaxation times. T2 mapping of articular cartilage is feasible in the clinical setting and may reveal early cartilage lesions not visible with standard clinical MRI.

Final report on the torque key komparison CCM.T-K1.2 measurand torque: 0 N.m, 500 N.m, 1000 N.m

NASA Astrophysics Data System (ADS)

Röske, Dirk

2015-01-01

The purpose of the CIPM subsequent bilateral comparison CCM.T-K1.2 was to link another participant, namely the National Institute of Metrology (Thailand), in short NIMT, to the CCM.T-K1 torque key comparison. The measuring capabilities up to 1000 N.m of dead-weight torque standard machines with supported lever were investigated. The pilot laboratory was the same in both comparisons—it was the Physikalisch-Technische Bundesanstalt (PTB, Braunschweig, Germany). The same two very stable torque transducers with well-known properties were used as travelling standards. The measurements at the participating laboratory were carried out between November 2007 and February 2008. According to the technical protocol, torque steps of 500 N.m and 1000 N.m had to be measured both in clockwise and anticlockwise directions. Corrections had to be applied to the results reported by the participants taking into account the use of different amplifiers, the creep (due to different loading times of the machines) and the environmental conditions in the laboratories (temperature and relative humidity of the ambient air). The results of the pilot laboratory in this bilateral comparison are in very good agreement with the same results obtained in the CCM.T-K1 comparison. For each of the transducers, the two torque steps and both senses of direction of the torque vector, the key comparison reference value of the CCM.T-K1 was taken, and the results of participant NIMT were calculated with respect to these values. The agreement between the results is very good. The smallest expanded (k = 2) relative uncertainty of the machine stated by the participant is 1 × 10-4. The results of the comparison support this uncertainty statement. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by CCM, according

10 K gate I(2)L and 1 K component analog compatible bipolar VLSI technology - HIT-2

NASA Astrophysics Data System (ADS)

Washio, K.; Watanabe, T.; Okabe, T.; Horie, N.

1985-02-01

An advanced analog/digital bipolar VLSI technology that combines on the same chip 2-ns 10 K I(2)L gates with 1 K analog devices is proposed. The new technology, called high-density integration technology-2, is based on a new structure concept that consists of three major techniques: shallow grooved-isolation, I(2)L active layer etching, and I(2)L current gain increase. I(2)L circuits with 80-MHz maximum toggle frequency have developed compatibly with n-p-n transistors having a BV(CE0) of more than 10 V and an f(T) of 5 GHz, and lateral p-n-p transistors having an f(T) of 150 MHz.

Experimental studies of Cl-atom reactions at high temperatures: Cl + H{sub 2} {yields} HCl + H from 291 to 1283 K

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adusei, G.Y.; Fontijn, A.

1994-12-31

A method is presented for producing Cl atoms for kinetic experiments above 750 K. Combined with a low temperature Cl-atom production technique, rate coefficients for the title reaction have been obtained over a wide temperature range. The Cl atoms were generated by flash photolysis of CCl{sub 4} for the low-temperature measurements and by pulsed laser photolysis of NaCl for the high-temperature measurements. The relative Cl-atom concentrations were monitored by time-resolved resonance fluorescence. The data are well fitted by the expression k{sub 1}(291--1,283 K) = 4.4 {times} 10{sup {minus}11} exp({minus}2568 K/T) cm{sup 3}/molecule, with 2{sigma} precision limits of {+-} 9 {+-}16more » %, depending on temperature, and corresponding 2{sigma} accuracy limits of about {+-} 26 %. There is good agreement between the rate coefficients measured here and those from previous low-temperature studies, leading to the recommendation k{sub 1}(200--1,283 K) = 2.3 {times} 10{sup {minus}16} (T/K){sup 1.63} exp({minus}1592 K/T) cm{sup 3}/molecule s, with a suggested 2{sigma} accuracy limit of {+-}28% for the combined data. A transition state theory calculation base don a semiempirical London-Eyring-Polanyi-Sato (LEPS) potential energy surface gives excellent agreement with the combined experimental results. Extension of their previous recommendation for the reverse reaction to lower temperatures leads to k{sub 2}(200--1,200 K) = 6.6 {times} 10{sup {minus}16} (T/K){sup 1.44} exp({minus}1241 K/T) cm{sup 3}/molecule s, with 2{sigma} accuracy limits within {+-}25 %. There is excellent agreement between the present data and the predicted expression from that reaction and equilibrium data.« less

Atmospheric Dispersion Capability for T2VOC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oldenburg, Curtis M.

2005-09-19

Atmospheric transport by variable-K theory dispersion has been added to T2VOC. The new code, T2VOCA, models flow and transport in the subsurface identically to T2VOC, but includes also the capability for modeling passive multicomponent variable-K theory dispersion in an atmospheric region assumed to be flat, horizontal, and with a logarithmic wind profile. The specification of the logarithmic wind profile in the T2VOC input file is automated through the use of a build code called ATMDISPV. The new capability is demonstrated on 2-D and 3-D example problems described in this report.

A Model Project in Career Education, K-12. Interim Report, December 1974.

ERIC Educational Resources Information Center

Wyoming State Dept. of Education, Cheyenne.

The document presents an interim report of a project to establish career education programs for K-12 students in the Natrona County School District of Casper, Wyoming. Project activities were divided into: (1) career awareness, grades K-6; (2) career exploration, grades 7-9; (3) career preparation, grades 10-12; and (4) guidance. To meet the…

Annealing temperature and O2 partial pressure dependence of T(sub c) in HgBa2CuO(4+delta)

NASA Technical Reports Server (NTRS)

Xiong, Q.; Cao, Y.; Chen, F.; Xue, Y. Y.; Chu, C. W.

1994-01-01

Samples of HgBa2CuO(4+delta) (Hg-1201) were annealed under various conditions. After carefully controlling annealing time, annealing temperature (T(sub a)) and O2 partial pressure (P(sub 0)), we were able to find the reversible annealing conditions for Hg-1201. Under 1 atm O2 at 260 C less than or equal to T(sub a) less than or equal to 400 C, the obtained T(sub c) is nearly the same (approximately 97 K). However, it decreases quickly with T(sub a) greater than 300 C in high vacuum (P(sub 0) approximately 10(exp -8) atm), and reaches zero at T(sub a) = 400 C. On the other hand, T(sub c) decreases with the decrease of T(sub a) in high-pressure O2 (approximately 500 atm) and reaches approximately 20 K at about 240 C. In the entire annealing region, the oxygen surplus varies significantly from 0.03 to 0.4, and a wide range of T(sub c) variation (0 goes to 97 K goes to 20 K) was obtained with anion doping alone.

First Safety and Performance Evaluation of T45K, a Self-Assembling Peptide Barrier Hemostatic Device, After Skin Lesion Excision.

PubMed

Rahmani, George; Prats, Jayne; Norchi, Terrence; Kates, Steven; McInerney, Veronica; Woods, Jack; Kelly, Jack

2018-01-29

The self-assembling peptide barrier T45K (SAPB-T45K) is an oligopeptide that rapidly forms a biocompatible hemostatic barrier when applied to wounds. Evaluate safety and performance of SAPB-T45K in cutaneous surgery. In this single-blind study, after sequential shave excision of 2 lesions, wounds were randomized (intrapatient) to SAPB-T45K or control treatment. Safety was assessed at treatment, Day 7, and Day 30. Performance was evaluated using time to hemostasis (TTH) and ASEPSIS wound scores, with a subgroup analysis for patients with or without antiplatelet therapy. Each of 46 patients (10 [22%] with antiplatelet therapy) received randomized SAPB-T45K or control treatment for 2 wounds. Safety assessments were similar, and ASEPSIS scores reflected normal healing in both wound groups. SAPB-T45K demonstrated significantly faster median TTH (24.5 [range, 7-165] seconds) compared with control (44 [10-387] seconds), for a 41% median TTH reduction (18 [95% confidence interval, 7-35] seconds, p < .001). SAPB-T45K provided an identical median TTH of 24 seconds, regardless of antiplatelet therapy. Control median TTH was 90 and 40 seconds for patients taking or not taking antiplatelet therapy, respectively. SAPB-T45K provided significantly faster median TTH versus control, especially with antiplatelet therapy, and safety profiles were similar.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

Two-level inhibition of galK expression by Spot 42: Degradation of mRNA mK2 and enhanced transcription termination before the galK gene

PubMed Central

Wang, Xun; Ji, Sang Chun; Jeon, Heung Jin; Lee, Yonho; Lim, Heon M.

2015-01-01

The Escherichia coli gal operon has the structure Pgal-galE-galT-galK-galM. During early log growth, a gradient in gene expression, named type 2 polarity, is established, as follows: galE > galT > galK > galM. However, during late-log growth, type 1 polarity is established in which galK is greater than galT, as follows: galE > galK > galT > galM. We found that type 2 polarity occurs as a result of the down-regulation of galK, which is caused by two different molecular mechanisms: Spot 42-mediated degradation of the galK-specific mRNA, mK2, and Spot 42-mediated Rho-dependent transcription termination at the end of galT. Because the concentration of Spot 42 drops during the transition period of the polarity type switch, these results demonstrate that type 1 polarity is the result of alleviation of Spot 42-mediated galK down-regulation. Because the Spot 42-binding site overlaps with a putative Rho-binding site, a molecular mechanism is proposed to explain how Spot 42, possibly with Hfq, enhances Rho-mediated transcription termination at the end of galT. PMID:26045496

T3 supplementation affects ventilatory timing & glucose levels in type 2 diabetes mellitus model.

PubMed

Bollinger, Stephen S; Weltman, Nathen Y; Gerdes, A Martin; Schlenker, Evelyn H

2015-01-01

Type II diabetes mellitus (T2DM) can affect ventilation, metabolism, and fasting blood glucose levels. Hypothyroidism may be a comorbidity of T2DM. In this study T2DM was induced in 20 female Sprague Dawley rats using Streptozotocin (STZ) and Nicotinamide (N). One of experimental STZ/N groups (N=10 per group) was treated with a low dose of triiodothyronine (T3). Blood glucose levels, metabolism and ventilation (in air and in response to hypoxia) were measured in the 3 groups. STZ/N-treated rats increased fasting blood glucose compared to control rats eight days and 2 months post-STZ/N injections indicating stable induction of T2DM state. Treatments had no effects on ventilation, metabolism or body weight. After one month of T3 supplementation, there were no physiological indications of hyperthyroidism, but T3 supplementation altered ventilatory timing and decreased blood glucose levels compared to STZ/N rats. These results suggest that low levels of T3 supplementation could offer modest effects on blood glucose and ventilatory timing in this T2M model. Copyright © 2014 Elsevier B.V. All rights reserved.

A Detailed Study of the Drastic Worldwide Climatic Change by the Cretaceous/Paleogene (K/T)-Impact of Chicxulub

NASA Astrophysics Data System (ADS)

Preisinger, Anton; Aslanian, Selma; Grass, Fritz; Beigelbeck, Roman; Wernisch, Johann

2010-05-01

The impact of Chicxulub (Yucatan, Mexico) was a global event exhibiting a short-time (fallout) and a long-time (boundary clay) sedimentation of the K/T-boundary [1]. The fallout is mainly characterized by iridium, Ni-Cr-rich magnesia-ferrite spinels (K/T-spinels), spherules, as well as shocked quartzes. The amount of the sediments and their distribution depend on the distance from the impact crater. The Cretaceous/Paleogene (K/T) boundaries at three different locations namely Caravaca (Spain), Cerbara (Italy), and Bjala (Bulgaria) have been well analyzed. About 65 million years ago, they were located at the distances from the impact crater ~6000 km, ~7500 km, and ~8800 km, respectively. The boundary clay is characterized by transported minerals like quartzes and feldspars, authigenically formed minerals, as well as biominerals like Mg-calcites and greigites (Fe3S4). The samples were analyzed by scanning X-ray diffractometry (Bruker Analytical X-ray System), scanning electronic microscopy (XL30, ESEM-Philips), neutron activation analyses, Delta13C and Delta18O analyses, and the determination of nannofossils and foraminifera. Owing to the Earth's rotation, the analyzed samples lie along a great circle (crossing the equator under an angle of ~23° ) which covers Chicxulub, Caravaca, Cerbara, and Bjala indicating the existence of only a single impact. The study of this K/T-boundary by means of high resolution scanning X-ray diffractometry in combination with the scanning electron microscopy and neutron activation analyzes revealed the time dependency of the K/T-event in the fallout as well as in the boundary clay. The biomineralization of sulfate-reducing bacteria by greigites provided the duration of the sulfuric acid rain. The reoccurrence of algae is indicated by the appearance of Mg-calcite at the end of the boundary clay. The K/T-spinels were formed on the nucleus of metallic iridium [2]. They were built in the mesosphere (in a height of about 100 km) and grew

Extended period of K/T boundary mass extinction in the marine realm

NASA Technical Reports Server (NTRS)

Keller, G.

1988-01-01

The Cretaceous/Tertiary (K/T) boundary mass extinction has been widely recognized as a nearly instantaneous catastrophy among marine plankton such as foraminifera. However, the suddenness of this extinction event may have been overemphasized because most pelagic K/T boundary sequences are stratigraphically incomplete and generally lack the earliest Tertiary (Zones P0 and P1a) either due to carbonate dissolution and/or non-deposition. Stratigraphically complete sections appear to be restricted to continental shelf regions with high sedimentation rates and deposition well above the CCD. Such sections have been recovered from El Kef, Tunisia (1) and Brazos River, Texas. Quantitative foraminiferal analysis of these sections indicate an extinction pattern beginning below the K/T boundary and ending above the boundary. These data imply that the mass extinction event was not geologically instantaneous, but occurred over an extended period of time. Evidence supporting this conclusion is discussed.

Measurement of numu induced charged current inclusive cross section on water using the near detector of the T2K experiment

NASA Astrophysics Data System (ADS)

Das, Rajarshi

The Tokai to Kamioka (T2K) Experiment is a long-baseline neutrino oscillation experiment located in Japan with the primary goal to measure precisely multiple neutrino flavor oscillation parameters. An off-axis muon neutrino beam peaking at 600 MeV is generated at the JPARC facility and directed towards the 50 kiloton Super-Kamiokande (SK) water Cherenkov detector located 295 km away. Measurements from a Near Detector that is 280m downstream of the neutrino beam target are used to constrain uncertainties in the beam flux prediction and neutrino interaction rates. We present a selection of inclusive charged current neutrino interactions on water. We used several sub-detectors in the ND280 complex, including a Pi-Zero detector (P0D) that has alternating planes of plastic scintillator and water bag layers, a time projection chamber (TPC) and fine-grained detector (FGD) to detect and reconstruct muons from neutrino charged current events. We use a statistical subtraction method with the water-in and water-out inclusive selection to extract a flux-averaged, ν_μ induced, charged current inclusive cross section. We also outline the evaluation of systematic uncertainties. We find an absolute cross section of ⟨σ⟩=(6.37 ± 0.157(stat.) (-1.060/+0.910(sys.)) x 10-39 (cm. 2/H2O nucleon). This is the first ν_μ charged current inclusive cross section measurement on water.

QCD dipole model and k T factorization

NASA Astrophysics Data System (ADS)

Bialas, A.; Navelet, H.; Peschanski, R.

2001-01-01

It is shown that the colour dipole approach to hard scattering at high energy is fully compatible with k T factorization at the leading logarithm approximation (in - logx Bj). The relations between the dipole amplitudes and unintegrated diagonal and non-diagonal gluon distributions are given. It is also shown that including the exact gluon kinematics in the k T factorization formula destroys the conservation of transverse position vectors and thus is incompatible with the dipole model for both elastic and diffractive amplitudes.

A subset of thalamocortical projections to the retrosplenial cortex possesses two vesicular glutamate transporter isoforms, VGluT1 and VGluT2, in axon terminals and somata.

PubMed

Oda, Satoko; Funato, Hiromasa; Sato, Fumi; Adachi-Akahane, Satomi; Ito, Masanori; Takase, Kenkichi; Kuroda, Masaru

2014-06-15

Vesicular glutamate transporter isoforms, VGluT1-VGluT3, accumulate glutamate into synaptic vesicles and are considered to be important molecules in glutamatergic transmission. Among them, VGluT2 mRNA is expressed predominantly throughout the dorsal thalamus, whereas VGluT1 mRNA is expressed in a few thalamic nuclei. In the thalamic nuclei that project to the retrosplenial cortex (RSC), VGluT1 mRNA is expressed strongly in the anterodorsal thalamic nucleus (AD), is expressed moderately in the anteroventral and laterodorsal thalamic nuclei, and is not expressed in the anteromedial thalamic nucleus. Thus, it has been strongly suggested that a subset of thalamocortical projections to RSC possesses both VGluT1 and VGluT2. In this study, double-labeled neuronal somata showing both VGluT1 and VGluT2 immunolabelings were found exclusively in the ventral region of AD (vAD). Many double-labeled axon terminals were also found in two major targets of vAD, the rostral part of the reticular thalamic nucleus and layers Ia and III-IV of the retrosplenial granular b cortex (RSGb). Some were also found in layer Ia of the retrosplenial granular a cortex (RSGa). These axon terminals contain significant amounts of both VGluTs. Because the subset of thalamocortical projections to RSC has a unique molecular basis in the glutamatergic transmission system, it might play an important role in the higher cognitive functions processed in the RSC. Furthermore, double-labeled axon terminals of a different type were distributed in RSGb and RSGa. Because they are small and the immunoreactivity of VGluT2 is significantly weaker than that of VGluT1, they seemed to be a subset of corticocortical terminals. Copyright © 2013 Wiley Periodicals, Inc.

Supra-aortic arteries: three-dimensional time-resolved k-t BLAST contrast-enhanced MRA using a nondedicated body coil at 3 tesla in acute ischemic stroke.

PubMed

Ferré, Jean-Christophe; Raoult, Hélène; Breil, Stéphane; Carsin-Nicol, Béatrice; Ronzière, Thomas; Gauvrit, Jean-Yves

2014-11-01

To assess the image quality and diagnostic performance achieved by using supra-aortic 3D-TR-CE-k-t BLAST MRA and a nondedicated body coil as compared with conventional CE-MRA in patients with acute ischemic stroke. In this prospective study, 36 consecutive patients with a suspected acute ischemic stroke underwent both k-t BLAST MRA and conventional CE-MRA. Image quality was assessed using visual and quantitative criteria and the techniques were compared. Both techniques were compared for degree of visual and quantitative measurement of carotid stenosis. Delineation of vessel lumen and overall diagnostic confidence were significantly better with CE-MRA, respectively 3.4 ± 0.5 and 3.3 ± 0.6 (mean score ± SD), than with k-t BLAST MRA, respectively 2.8 ± 0.4 and 2.9 ± 0.5 (P < 0.02). SNR and CNR were significantly higher for k-t BLAST MRA, respectively 33.5 ± 19.3 and 27.9 ± 19.3, than for CE-MRA, respectively 25.7 ± 10 and 20.4 ± 8.4 (P < 0.03). Intertechnique agreement was good for carotid stenosis characterization (κ = .763). For the 14 relevant stenosis, stenosis measurements were highly correlated between techniques (0.96; P < 0.0001). The Bland-Altman plot showed a low bias in assessment of the degree of stenosis (mean bias 2.1% ± 7.7). k-t BLAST MRA using a nondedicated coil offering and dynamic information was a effective diagnostic tool for detection and characterization of carotid stenosis. © 2013 Wiley Periodicals, Inc.

Gaseous time projection chambers for rare event detection: results from the T-REX project. II. Dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Irastorza, I.G.; Aznar, F.; Castel, J., E-mail: igor.irastorza@cern.ch, E-mail: faznar@unizar.es, E-mail: jfcastel@unizar.es

As part of the T-REX project, a number of R and D and prototyping activities have been carried out during the last years to explore the applicability of gaseous Time Projection Chambers (TPCs) with Micromesh Gas Structures (Micromegas) in rare event searches like double beta decay, axion research and low-mass WIMP searches. While in the companion paper we focus on double beta decay, in this paper we focus on the results regarding the search for dark matter candidates, both axions and WIMPs. Small (few cm wide) ultra-low background Micromegas detectors are used to image the axion-induced x-ray signal expected inmore » axion helioscopes like the CERN Axion Solar Telescope (CAST) experiment. Background levels as low as 0.8 × 10{sup −6} counts keV{sup −1} cm{sup −2} s{sup −1} have already been achieved in CAST while values down to ∼10{sup −7} counts keV{sup −1} cm{sup −2} s{sup −1} have been obtained in a test bench placed underground in the Laboratorio Subterráneo de Canfranc (LSC). Prospects to consolidate and further reduce these values down to ∼10{sup −8} counts keV{sup −1} cm{sup −2} s{sup −1} will be described. Such detectors, placed at the focal point of x-ray telescopes in the future International Axion Observatory (IAXO), would allow for 10{sup 5} better signal-to-noise ratio than CAST, and search for solar axions with g{sub a}γ down to few 10{sup 12} GeV{sup −1}, well into unexplored axion parameter space. In addition, a scaled-up version of these TPCs, properly shielded and placed underground, can be competitive in the search for low-mass WIMPs. The TREX-DM prototype, with ∼ 0.300 kg of Ar at 10 bar, or alternatively ∼ 0.160 kg of Ne at 10 bar, and energy threshold well below 1 keV, has been built to test this concept. We will describe the main technical solutions developed, as well as the results from the commissioning phase on surface. The anticipated sensitivity of this technique might reach ∼10{sup −44} cm

Critters: K-6 Life Science Activities. Project AIMS.

ERIC Educational Resources Information Center

Allen, Maureen Murphy; And Others

Project AIMS (Activities to Integrate Mathematics and Science) has as its purpose the integration of subject matter in grades K-9. Field testing of the curriculum materials produced by AIMS indicates that this integration produces the following beneficial results: (1) mathematics becomes more meaningful, hence more useful; (2) science is…

Impact and extinction signatures in complete Cretaceous-Tertiary (K-T) boundary sections

NASA Technical Reports Server (NTRS)

Smit, J.; Groot, H.; Dejonge, R.; Smit, P.

1988-01-01

The Zumaya, Caravaca and Agost sections in Spain, the El Kef section in Tunisia and the Negev (Nahal Avdat) sections in Israel are among the most continuous, expanded and complete K-T boundary sections. The distribution patterns of the planktic faunas were quantitatively analyzed in closely spaced samples across the K-T boundary in these sections, in conjuction with the geochemistry, stable isotopes, mineralogy and magnetostratigraphy. Three hundred foraminiferal specimens were randomly selected and determined. Reliable estimates for the foraminiferal productivity changes across the K-T boundary and for the 1 to 2 Ma interval preceding the K-T boundary were made from the numbers of individuals/gram of sediment corrected for the sedimentation rates (calculated from magnetic reversals and lithology). No gradual or stepwise extinction is seen below the K-T boundary nor any productivity decrease. Stable isotope analyses show a warming just after deposition of the ejecta layer, not cooling as predicted by nuclear winter scenarios, although the duration of such cooling may be too short to be observed even in these complete sections. Low REE values and cpx spherules with quench textures idential to quench-textures in diagenetically altered spherules, strongly indicate an oceanic site of (one of) the impactor(s).

Generation of virtual monochromatic CBCT from dual kV/MV beam projections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Hao; Liu, Bo; Yin, Fang-Fang, E-mail: fangfang.yin@duke.edu

Purpose: To develop a novel on-board imaging technique which allows generation of virtual monochromatic (VM) cone-beam CT (CBCT) with a selected energy from combined kilovoltage (kV)/megavoltage (MV) beam projections. Methods: With the current orthogonal kV/MV imaging hardware equipped in modern linear accelerators, both MV projections (from gantry angle of 0°–100°) and kV projections (90°–200°) were acquired as gantry rotated a total of 110°. A selected range of overlap projections between 90° to 100° were then decomposed into two material projections using experimentally determined parameters from orthogonally stacked aluminum and acrylic step-wedges. Given attenuation coefficients of aluminum and acrylic at amore » predetermined energy, one set of VM projections could be synthesized from two corresponding sets of decomposed projections. Two linear functions were generated using projection information at overlap angles to convert kV and MV projections at nonoverlap angles to approximate VM projections for CBCT reconstruction. The contrast-to-noise ratios (CNRs) were calculated for different inserts in VM CBCTs of a CatPhan phantom with various selected energies and compared with those in kV and MV CBCTs. The effect of overlap projection number on CNR was evaluated. Additionally, the effect of beam orientation was studied by scanning the CatPhan sandwiched with two 5 cm solid-water phantoms on both lateral sides and an electronic density phantom with two metal bolt inserts. Results: Proper selection of VM energy [30 and 40 keV for low-density polyethylene (LDPE), polymethylpentene, 2 MeV for Delrin] provided comparable or even better CNR results as compared with kV or MV CBCT. An increased number of overlap kV and MV projection demonstrated only marginal improvements of CNR for different inserts (with the exception of LDPE) and therefore one projection overlap was found to be sufficient for the CatPhan study. It was also evident that the optimal CBCT

Generation of virtual monochromatic CBCT from dual kV/MV beam projections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Hao; Liu, Bo; Yin, Fang-Fang, E-mail: fangfang.yin@duke.edu

2013-12-15

Purpose: To develop a novel on-board imaging technique which allows generation of virtual monochromatic (VM) cone-beam CT (CBCT) with a selected energy from combined kilovoltage (kV)/megavoltage (MV) beam projections. Methods: With the current orthogonal kV/MV imaging hardware equipped in modern linear accelerators, both MV projections (from gantry angle of 0°–100°) and kV projections (90°–200°) were acquired as gantry rotated a total of 110°. A selected range of overlap projections between 90° to 100° were then decomposed into two material projections using experimentally determined parameters from orthogonally stacked aluminum and acrylic step-wedges. Given attenuation coefficients of aluminum and acrylic at amore » predetermined energy, one set of VM projections could be synthesized from two corresponding sets of decomposed projections. Two linear functions were generated using projection information at overlap angles to convert kV and MV projections at nonoverlap angles to approximate VM projections for CBCT reconstruction. The contrast-to-noise ratios (CNRs) were calculated for different inserts in VM CBCTs of a CatPhan phantom with various selected energies and compared with those in kV and MV CBCTs. The effect of overlap projection number on CNR was evaluated. Additionally, the effect of beam orientation was studied by scanning the CatPhan sandwiched with two 5 cm solid-water phantoms on both lateral sides and an electronic density phantom with two metal bolt inserts. Results: Proper selection of VM energy [30 and 40 keV for low-density polyethylene (LDPE), polymethylpentene, 2 MeV for Delrin] provided comparable or even better CNR results as compared with kV or MV CBCT. An increased number of overlap kV and MV projection demonstrated only marginal improvements of CNR for different inserts (with the exception of LDPE) and therefore one projection overlap was found to be sufficient for the CatPhan study. It was also evident that the optimal CBCT

CC-inclusive cross section measured with the T2K near detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weber, Alfons; STFC Rutherford Appleton Laboratory, Harwell, Didcot OX11 0QX

2015-05-15

T2K has performed the first measurement of muon neutrino inclusive charged current interactions on carbon at neutrino energies of ∼1 GeV where the measurement is reported as a flux-averaged double differential cross section in muon momentum and angle. The flux is predicted by the beam Monte Carlo and external data, including the results from the NA61/SHINE experiment. The data used for this measurement were taken in 2010 and 2011, with a total of 1.08*10{sup 20} protons-on-target. The analysis is performed on 4485 inclusive charged current interaction candidates selected in the most upstream fine-grained scintillator detector of the near detector. Themore » flux-averaged total cross section is = (6.91±0.13(stat)±0.84(syst)) 10{sup −39} cm{sup 2}/nucleon for a mean neutrino energy of 0.85 GeV.« less

Y2K: prepare, don't panic.

PubMed

Russo, R

1999-04-01

Y2K issues could affect anyone, so it is important for HIV-positive people to make preparations to ensure their health and security. There are wide-ranging opinions about the effects of the so-called Millennium Bug, but some planning will make any changes more manageable. Patients should have adequate supplies of food, water, and medications at home in case of shortages or production problems. Other prudent steps include keeping extra cash on hand and obtaining copies of medical records and benefit plans. Internet resources are listed.

Short-time dynamics of molecular junctions after projective measurement

NASA Astrophysics Data System (ADS)

Tang, Gaomin; Xing, Yanxia; Wang, Jian

2017-08-01

In this work, we study the short-time dynamics of a molecular junction described by Anderson-Holstein model using full-counting statistics after projective measurement. The coupling between the central quantum dot (QD) and two leads was turned on at remote past and the system is evolved to steady state at time t =0 , when we perform the projective measurement in one of the lead. Generating function for the charge transfer is expressed as a Fredholm determinant in terms of Keldysh nonequilibrium Green's function in the time domain. It is found that the current is not constant at short times indicating that the measurement does perturb the system. We numerically compare the current behaviors after the projective measurement with those in the transient regime where the subsystems are connected at t =0 . The universal scaling for high-order cumulants is observed for the case with zero QD occupation due to the unidirectional transport at short times. The influences of electron-phonon interaction on short-time dynamics of electric current, shot noise, and differential conductance are analyzed.

Mineralogical and geochemical anomalous data of the K-T boundary samples

NASA Technical Reports Server (NTRS)

Miura, Y.; Shibya, G.; Imai, M.; Takaoka, N.; Saito, S.

1988-01-01

Cretaceous-Tertiary boundary problem has been discussed previously from the geological research, mainly by fossil changes. Although geochemical bulk data of Ir anomaly suggest the extraterrestrial origin of the K-T boundary, the exact formation process discussed mainly by mineralogical and geochemical study has been started recently, together with noble gas contents. The K-T boundary sample at Kawaruppu River, Hokkaido was collected, in order to compare with the typical K-T boundary samples of Bubbio, Italy, Stevns Klint, Denmark, and El Kef, Tunisia. The experimental data of the silicas and calcites in these K-T boundary samples were obtained from the X-ray unit-cell dimension (i.e., density), ESR signal and total linear absorption coefficient, as well as He and Ne contents. The K-T boundary samples are usually complex mixture of the terrestrial activities after the K-T boundary event. The mineralogical and geochemical anomalous data indicate special terrestrial atmosphere at the K-T boundary formation probably induced by asteroid impact, followed the many various terrestrial activities (especially the strong role of sea-water mixture, compared with terrestrial highland impact and impact craters in the other earth-type planetary bodies).

Magnetism of the spin-1 tetramer compound A2Ni2Mo3O12(A =Rb or K)

NASA Astrophysics Data System (ADS)

Hase, Masashi; Matsuo, Akira; Kindo, Koichi; Matsumoto, Masashige

2017-12-01

We measured the temperature dependence of the magnetic susceptibility χ (T ) and the specific heat C (T ) and the magnetic-field dependence of the magnetization M (H ) of A2Ni2Mo3O12 (A = Rb or K) powder. We consider that the probable spin model is an interacting spin-1 antiferromagnetic tetramer model. We evaluated values of the intratetramer interactions as J1=9 K and J2=18 K, and the effective intertetramer interaction as Jeff=4 K for Rb2Ni2Mo3O12 . The susceptibility and magnetization at 1.3 K of K2Ni2Mo3O12 are very close to those of Rb2Ni2Mo3O12 . We observed a phase transition to a magnetically ordered state in C (T )/T in magnetic fields above 3 T. The transition temperature increases with magnetic field. Probably, the ordered state appears around 1.8 K even in 0 T. The ordered state in 0 T, however, is not stable enough like an order in the vicinity of a quantum critical point. Longitudinal-mode magnetic excitations may be observable in single crystalline A2Ni2Mo3O12 (A = Rb or K).

La 139 and Cu 63 NMR investigation of charge order in La 2 CuO 4 + y ( T c = 42 K)

DOE PAGES

Imai, T.; Lee, Y. S.

2018-03-14

Here, we report 139La and 63Cu NMR investigation of the successive charge order, spin order, and superconducting transitions in superoxygenated La 2CuO 4+y single crystal with stage-4 excess oxygen order at T stage≃290 K. We show that the stage-4 order induces tilting of CuO 6 octahedra below T stage, which in turn causes 139La NMR line broadening. The structural distortion continues to develop far below Tstage, and completes at T charge≃60 K, where charge order sets in. This sequence is reminiscent of the the charge-order transition in Nd codoped La 1.88Sr 0.12CuO 4 that sets in once the low-temperature tetragonalmore » phase is established. We also show that the paramagnetic 63Cu NMR signals are progressively wiped out below T charge due to enhanced low-frequency spin fluctuations in charge-ordered domains, but the residual 63Cu NMR signals continue to exhibit the characteristics expected for optimally doped superconducting CuO 2 planes. This indicates that charge order in La 2CuO 4+y does not take place uniformly in space. In addition, unlike the typical second-order magnetic phase transitions, low-frequency Cu spin fluctuations as probed by 139La nuclear spin-lattice relaxation rate do not exhibit critical divergence at T spin(≃T c) =42 K. These findings, including the spatially inhomogeneous nature of the charge-ordered state, are qualitatively similar to the case of La 1.885Sr 0.115CuO 4, but both charge and spin order take place more sharply in the present case.« less

La 139 and Cu 63 NMR investigation of charge order in La 2 CuO 4 + y ( T c = 42 K)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Imai, T.; Lee, Y. S.

Here, we report 139La and 63Cu NMR investigation of the successive charge order, spin order, and superconducting transitions in superoxygenated La 2CuO 4+y single crystal with stage-4 excess oxygen order at T stage≃290 K. We show that the stage-4 order induces tilting of CuO 6 octahedra below T stage, which in turn causes 139La NMR line broadening. The structural distortion continues to develop far below Tstage, and completes at T charge≃60 K, where charge order sets in. This sequence is reminiscent of the the charge-order transition in Nd codoped La 1.88Sr 0.12CuO 4 that sets in once the low-temperature tetragonalmore » phase is established. We also show that the paramagnetic 63Cu NMR signals are progressively wiped out below T charge due to enhanced low-frequency spin fluctuations in charge-ordered domains, but the residual 63Cu NMR signals continue to exhibit the characteristics expected for optimally doped superconducting CuO 2 planes. This indicates that charge order in La 2CuO 4+y does not take place uniformly in space. In addition, unlike the typical second-order magnetic phase transitions, low-frequency Cu spin fluctuations as probed by 139La nuclear spin-lattice relaxation rate do not exhibit critical divergence at T spin(≃T c) =42 K. These findings, including the spatially inhomogeneous nature of the charge-ordered state, are qualitatively similar to the case of La 1.885Sr 0.115CuO 4, but both charge and spin order take place more sharply in the present case.« less

Fingerprinting the K/T impact site and determining the time of impact by U-Pb dating of single shocked zircons from distal ejecta

NASA Technical Reports Server (NTRS)

Krogh, T. E.; Kamo, S. L.; Bohor, B. F.

1993-01-01

U-Pb isotopic dating of single 1 - 3 micrograms zircons from K/T distal ejecta from a site in the Raton Basin, Colorado provides a powerful new tool with which to determine both the time of the impact event and the age of the basement at the impact site. Data for the least shocked zircons are slightly displaced from the 544 +/- 5 Ma primary age for a component of the target site, while those for highly shocked and granular grains are strongly displaced towards the time of impact at 65.5 +/- 3.0 Ma. Such shocked and granular zircons have never been reported from any source, including explosive volcanic rocks. Zircon is refractory and has one of the highest thermal blocking temperatures; hence, it can record both shock features and primary and secondary ages without modification by post-crystallization processes. Unlike shocked quartz, which can come from almost anywhere on the Earth's crust, shocked zircons can be shown to come from a specific site because basement ages vary on the scale of meters to kilometers. With U-Pb zircon dating, it is now possible to correlate ejecta layers derived from the same target site, test the single versus multiple impact hypothesis, and identify the target source of impact ejecta. The ages obtained in this study indicate that the Manson impact site, Iowa, which has basement rocks that are mid-Proterozoic in age, cannot be the source of K/T distal ejecta. The K/T distal ejecta probably originated from a single impact site because most grains have the same primary age.

Development of 4.5 kW SPT T-160 for Joint Tests with NPP TOPAZ-2

NASA Astrophysics Data System (ADS)

Koroteev, Anatoly; Petrosov, Valery A.; Vasin, Anatoly L.; Baranov, Vladimir L.; Rebrov, Serdei G.; Wetch, Joseph R.; Wong, See-Pok

1994-07-01

The electric thruster T-160 is related to a low thrust rocket engines group which can be used on spacecrafts for their orbit correction and parameters change. T-160 flight tests are supposed to be conducted together with the TOPAZ-2 Nuclear Power Plant (NPP) as a part of the NEPSTP program. The thruster T-160 is a Hall-type plasma accelerator with the closed electron drift. Plasma is accelerated in crossed magnetic and electric fields in an accelerating channel made of insulating material. Gaseous xenon is used as a propellant for the thruster, electric power supply of 4-4.5 kW is required for its operation. The cathode-neutralizer emission element is made of porous tungsten saturated with barium salts. The thruster T-160 is equipped with a flow control unit ensuring propellant coming to the cathode and gas distributing anode, and a power processing unit and can be delivered with a propellant storage and supply system, thus forming a complete propulsion system set.

Absence of both Sos-1 and Sos-2 in peripheral CD4+ T cells leads to PI3K pathway activation and defects in migration

PubMed Central

Guittard, Geoffrey; Kortum, Robert L; Balagopalan, Lakshmi; Çuburu, Nicolas; Nguyen, Phan; Sommers, Connie L; Samelson, Lawrence E

2015-01-01

Sos-1 and Sos-2 are ubiquitously expressed Ras-Guanine Exchange Factors involved in Erk-MAP kinase pathway activation. Using mice lacking genes encoding Sos-1 and Sos-2, we evaluated the role of these proteins in peripheral T-cell signaling and function. Our results confirmed that TCR-mediated Erk activation in peripheral CD4+ T cells does not depend on Sos-1 and Sos-2, although IL-2-mediated Erk activation does. Unexpectedly, however, we show an increase in AKT phosphorylation in Sos-1/2dKO CD4+ T cells upon TCR and IL-2 stimulation. Activation of AKT was likely a consequence of increased recruitment of PI3K to Grb2 upon TCR and/or IL-2 stimulation in Sos-1/2dKO CD4+ T cells. The increased activity of the PI3K/AKT pathway led to downregulation of the surface receptor CD62L in Sos-1/2dKO T cells and a subsequent impairment in T-cell migration. PMID:25973715

The GEM-T2 gravitational model

NASA Technical Reports Server (NTRS)

Marsh, J. G.; Lerch, F. J.; Putney, B. H.; Felsentreger, T. L.; Sanchez, B. V.; Klosko, S. M.; Patel, G. B.; Robbins, J. W.; Williamson, R. G.; Engelis, T. E.

1989-01-01

The GEM-T2 is the latest in a series of Goddard Earth Models of the terrestrial field. It was designed to bring modeling capabilities one step closer towards ultimately determining the TOPEX/Poseidon satellite's radial position to an accuracy of 10-cm RMS (root mean square). It also improves models of the long wavelength geoid to support many oceanographic and geophysical applications. The GEM-T2 extends the spherical harmonic field to include more than 600 coefficients above degree 36 (which was the limit for its predecessor, GEM-T1). Like GEM-T1, it was produced entirely from satellite tracking data, but it now uses nearly twice as many satellites (31 vs. 17), contains four times the number of observations (2.4 million), has twice the number of data arcs (1132), and utilizes precise laser tracking from 11 satellites. The estimation technique for the solution has been augmented to include an optimum data weighting procedure with automatic error calibration for the gravitational parameters. Results for the GEM-T2 error calibration indicate significant improvement over previous satellite-only models. The error of commission in determining the geoid has been reduced from 155 cm in GEM-T1 to 105 cm for GEM-T2 for the 36 x 36 portion of the field, and 141 cm for the entire model. The orbital accuracies achieved using GEM-T2 are likewise improved. Also, the projected radial error on the TOPEX satellite orbit indicates 9.4 cm RMS for GEM-T2, compared to 24.1 cm for GEM-T1.

Cartilage and meniscal T2 relaxation time as non-invasive biomarker for knee osteoarthritis and cartilage repair procedures

PubMed Central

Baum, T.; Joseph, G.B.; Karampinos, D.C.; Jungmann, P.M.; Link, T.M.; Bauer, J.S.

2014-01-01

SUMMARY Objective The purpose of this work was to review the current literature on cartilage and meniscal T2 relaxation time. Methods Electronic searches in PubMed were performed to identify relevant studies about T2 relaxation time measurements as non-invasive biomarker for knee osteoarthritis (OA) and cartilage repair procedures. Results Initial osteoarthritic changes include proteoglycan loss, deterioration of the collagen network, and increased water content within the articular cartilage and menisci. T2 relaxation time measurements are affected by these pathophysiological processes. It was demonstrated that cartilage and meniscal T2 relaxation time values were significantly increased in subjects with compared to those without radiographic OA and focal knee lesions, respectively. Subjects with OA risk factors such as overweight/obesity showed significantly greater cartilage T2 values than normal controls. Elevated cartilage and meniscal T2 relaxation times were found in subjects with vs without knee pain. Increased cartilage T2 at baseline predicted morphologic degeneration in the cartilage, meniscus, and bone marrow over 3 years. Furthermore, cartilage repair tissue could be non-invasively assessed by using T2 mapping. Reproducibility errors for T2 measurements were reported to be smaller than the T2 differences in healthy and diseased cartilage indicating that T2 relaxation time may be a reliable discriminatory biomarker. Conclusions Cartilage and meniscal T2 mapping may be suitable as non-invasive biomarker to diagnose early stages of knee OA and to monitor therapy of OA. PMID:23896316

Updated T2K measurements of muon neutrino and antineutrino disappearance using 1.5 ×1 021 protons on target

NASA Astrophysics Data System (ADS)

Abe, K.; Amey, J.; Andreopoulos, C.; Antonova, M.; Aoki, S.; Ariga, A.; Ashida, Y.; Autiero, D.; Ban, S.; Barbi, M.; Barker, G. J.; Barr, G.; Barry, C.; Bartet-Friburg, P.; Batkiewicz, M.; Berardi, V.; Berkman, S.; Bhadra, S.; Bienstock, S.; Blondel, A.; Bolognesi, S.; Bordoni, S.; Boyd, S. B.; Brailsford, D.; Bravar, A.; Bronner, C.; Buizza Avanzini, M.; Calland, R. G.; Campbell, T.; Cao, S.; Cartwright, S. L.; Catanesi, M. G.; Cervera, A.; Chappell, A.; Checchia, C.; Cherdack, D.; Chikuma, N.; Christodoulou, G.; Clifton, A.; Coleman, J.; Collazuol, G.; Coplowe, D.; Cudd, A.; Dabrowska, A.; De Rosa, G.; Dealtry, T.; Denner, P. F.; Dennis, S. R.; Densham, C.; Dewhurst, D.; Di Lodovico, F.; Dolan, S.; Drapier, O.; Duffy, K. E.; Dumarchez, J.; Dunne, P.; Dziewiecki, M.; Emery-Schrenk, S.; Ereditato, A.; Feusels, T.; Finch, A. J.; Fiorentini, G. A.; Friend, M.; Fujii, Y.; Fukuda, D.; Fukuda, Y.; Galymov, V.; Garcia, A.; Giganti, C.; Gizzarelli, F.; Golan, T.; Gonin, M.; Hadley, D. R.; Haegel, L.; Haigh, J. T.; Hansen, D.; Harada, J.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayashino, T.; Hayato, Y.; Helmer, R. L.; Hillairet, A.; Hiraki, T.; Hiramoto, A.; Hirota, S.; Hogan, M.; Holeczek, J.; Hosomi, F.; Huang, K.; Ichikawa, A. K.; Ikeda, M.; Imber, J.; Insler, J.; Intonti, R. A.; Ishida, T.; Ishii, T.; Iwai, E.; Iwamoto, K.; Izmaylov, A.; Jamieson, B.; Jiang, M.; Johnson, S.; Jonsson, P.; Jung, C. K.; Kabirnezhad, M.; Kaboth, A. C.; Kajita, T.; Kakuno, H.; Kameda, J.; Karlen, D.; Katori, T.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kim, H.; Kim, J.; King, S.; Kisiel, J.; Knight, A.; Knox, A.; Kobayashi, T.; Koch, L.; Koga, T.; Koller, P. P.; Konaka, A.; Kormos, L. L.; Korzenev, A.; Koshio, Y.; Kowalik, K.; Kropp, W.; Kudenko, Y.; Kurjata, R.; Kutter, T.; Lagoda, J.; Lamont, I.; Lamoureux, M.; Larkin, E.; Lasorak, P.; Laveder, M.; Lawe, M.; Licciardi, M.; Lindner, T.; Liptak, Z. J.; Litchfield, R. P.; Li, X.; Longhin, A.; Lopez, J. P.; Lou, T.; Ludovici, L.; Lu, X.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Maret, L.; Marino, A. D.; Martin, J. F.; Martins, P.; Martynenko, S.; Maruyama, T.; Matveev, V.; Mavrokoridis, K.; Ma, W. Y.; Mazzucato, E.; McCarthy, M.; McCauley, N.; McFarland, K. S.; McGrew, C.; Mefodiev, A.; Metelko, C.; Mezzetto, M.; Mijakowski, P.; Minamino, A.; Mineev, O.; Mine, S.; Missert, A.; Miura, M.; Moriyama, S.; Morrison, J.; Mueller, Th. A.; Myslik, J.; Nakadaira, T.; Nakahata, M.; Nakamura, K. G.; Nakamura, K.; Nakamura, K. D.; Nakanishi, Y.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Nantais, C.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; Novella, P.; Nowak, J.; O'Keeffe, H. M.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Ovsyannikova, T.; Owen, R. A.; Oyama, Y.; Palladino, V.; Palomino, J. L.; Paolone, V.; Patel, N. D.; Paudyal, P.; Pavin, M.; Payne, D.; Perkin, J. D.; Petrov, Y.; Pickard, L.; Pickering, L.; Pinzon Guerra, E. S.; Pistillo, C.; Popov, B.; Posiadala-Zezula, M.; Poutissou, J.-M.; Poutissou, R.; Pritchard, A.; Przewlocki, P.; Quilain, B.; Radermacher, T.; Radicioni, E.; Ratoff, P. N.; Ravonel, M.; Rayner, M. A.; Redij, A.; Reinherz-Aronis, E.; Riccio, C.; Rondio, E.; Rossi, B.; Roth, S.; Rubbia, A.; Ruggeri, A. C.; Rychter, A.; Sakashita, K.; Sánchez, F.; Scantamburlo, E.; Scholberg, K.; Schwehr, J.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sgalaberna, D.; Shah, R.; Shaikhiev, A.; Shaker, F.; Shaw, D.; Shiozawa, M.; Shirahige, T.; Short, S.; Smy, M.; Sobczyk, J. T.; Sobel, H.; Sorel, M.; Southwell, L.; Steinmann, J.; Stewart, T.; Stowell, P.; Suda, Y.; Suvorov, S.; Suzuki, A.; Suzuki, S. Y.; Suzuki, Y.; Tacik, R.; Tada, M.; Takeda, A.; Takeuchi, Y.; Tamura, R.; Tanaka, H. K.; Tanaka, H. A.; Terhorst, D.; Terri, R.; Thakore, T.; Thompson, L. F.; Tobayama, S.; Toki, W.; Tomura, T.; Touramanis, C.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Vagins, M.; Vallari, Z.; Vasseur, G.; Vilela, C.; Vladisavljevic, T.; Wachala, T.; Walter, C. W.; Wark, D.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilkes, R. J.; Wilking, M. J.; Wilkinson, C.; Wilson, J. R.; Wilson, R. J.; Wret, C.; Yamada, Y.; Yamamoto, K.; Yamamoto, M.; Yanagisawa, C.; Yano, T.; Yen, S.; Yershov, N.; Yokoyama, M.; Yoshida, K.; Yuan, T.; Yu, M.; Zalewska, A.; Zalipska, J.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Żmuda, J.; T2K Collaboration

2017-07-01

We report measurements by the T2K experiment of the parameters θ23 and Δ m322 governing the disappearance of muon neutrinos and antineutrinos in the three-flavor neutrino oscillation model. Utilizing the ability of the experiment to run with either a mainly neutrino or a mainly antineutrino beam, the parameters are measured separately for neutrinos and antineutrinos. Using 7.482 ×1 020 POT in neutrino running mode and 7.471 ×1 020 POT in antineutrino mode, T2K obtained sin2(θ23)=0.5 1-0.07+0.08 and Δ m322=2.5 3-0.13+0.15×10-3 eV2/c4 for neutrinos, and sin2(θ¯23)=0.4 2-0.07+0.25 and Δm¯ 2 32=2.5 5-0.27+0.33×10-3 eV2/c4 for antineutrinos (assuming normal mass ordering). No significant differences between the values of the parameters describing the disappearance of muon neutrinos and antineutrinos were observed.

Myocardial effective transverse relaxation time T2* Correlates with left ventricular wall thickness: A 7.0 T MRI study.

PubMed

Huelnhagen, Till; Hezel, Fabian; Serradas Duarte, Teresa; Pohlmann, Andreas; Oezerdem, Celal; Flemming, Bert; Seeliger, Erdmann; Prothmann, Marcel; Schulz-Menger, Jeanette; Niendorf, Thoralf

2017-06-01

Myocardial effective relaxation time T2* is commonly regarded as a surrogate for myocardial tissue oxygenation. However, it is legitimate to assume that there are multiple factors that influence T2*. To this end, this study investigates the relationship between T2* and cardiac macromorphology given by left ventricular (LV) wall thickness and left ventricular radius, and provides interpretation of the results in the physiological context. High spatio-temporally resolved myocardial CINE T2* mapping was performed in 10 healthy volunteers using a 7.0 Tesla (T) full-body MRI system. Ventricular septal wall thickness, left ventricular inner radius, and T2* were analyzed. Macroscopic magnetic field changes were elucidated using cardiac phase-resolved magnetic field maps. Ventricular septal T2* changes periodically over the cardiac cycle, increasing in systole and decreasing in diastole. Ventricular septal wall thickness and T2* showed a significant positive correlation, whereas the inner LV radius and T2* were negatively correlated. The effect of macroscopic magnetic field gradients on T2* can be considered minor in the ventricular septum. Our findings suggest that myocardial T2* is related to tissue blood volume fraction. Temporally resolved T2* mapping could be beneficial for myocardial tissue characterization and for understanding cardiac (patho)physiology in vivo. Magn Reson Med 77:2381-2389, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Geochemical evidence for combustion of hydrocarbons during the K-T impact event

PubMed Central

Belcher, Claire M.; Finch, Paul; Collinson, Margaret E.; Scott, Andrew C.; Grassineau, Nathalie V.

2009-01-01

It has been proposed that extensive wildfires occurred after the Cretaceous–Tertiary (K-T) impact event. An abundance of soot and pyrosynthetic polycyclic aromatic hydrocarbons (pPAHs) in marine K-T boundary impact rocks (BIRs) have been considered support for this hypothesis. However, nonmarine K-T BIRs, from across North America, contain only rare occurrences of charcoal yet abundant noncharred plant remains. pPAHs and soot can be formed from a variety of sources, including partial combustion of vegetation and hydrocarbons whereby modern pPAH signatures are traceable to their source. We present results from multiple nonmarine K-T boundary sites from North America and reveal that the K-T BIRs have a pPAH signature consistent with the combustion of hydrocarbons and not living plant biomass, providing further evidence against K-T wildfires and compelling evidence that a significant volume of hydrocarbons was combusted during the K-T impact event. PMID:19251660

On the reaction of the NH 2 radical with NO at 295-620 K

NASA Astrophysics Data System (ADS)

Bulatov, V. P.; Ioffe, A. A.; Lozovsky, V. A.; Sarkisov, O. M.

1989-09-01

The reaction of the NH 2 radical with NO, NH 2+NO→ k1 products, was investigated using intracavity laser spectroscopy. The temperature dependence of k1( T) over the range 295-620 K is well approximated by the expression k1( T)=(2.0±0.4)×10 -11×( T/298) -2.2 cm 3 s -1. The branching ratios for the OH radical, α=( k1b+ k1c)/ k1, where NH 2+NO→ k1b N 2H+OH→ k1c N 2+H+OH, obtained at different temperatures over the range 295-620 K are as follows: α(295 K)=0.1±0.02; α(470 K)=0.14±0.03; α(620 K)=0.2±0.04.

Darkness after the K-T impact: Effects of soot

NASA Technical Reports Server (NTRS)

Wolbach, Wendy S.; Anders, Edward; Orth, Charles J.

1988-01-01

Dust from the K-T impact apparently settled from the atmosphere in less than 6 months, restoring sunlight to minimum photosynthesis levels in about 4 months. However, the discovery of a global soot component in the boundary clay makes it necessary to reconsider the problem, as soot particles not only are smaller (0.1 vs. about 0.5 micrometer) and thus settle more slowly, but also are better light absorbers (optical depth of 13 mg soot cm(-2) about 1800; and are more resistant to rainout. Still, the darkness cannot have lasted very much longer than 6 months, else no larger animals would have survived. Perhaps the soot coagulated with the rock dust and fell out with it. Evidence on this point may be sought at a relatively undisturbed K-T boundary site, such as Woodside Creek, N.Z. There the boundary clay and lowermost Tertiary strata are finely laminated and show large chemical and isotopic differences on a millimeter scale, apparently representing a detailed time sequence. Researchers studied a 3 m section across the boundary at this site, analyzing the principal forms of carbon (soot, elemental C, kerogen, and carbonate) as well as 33 elements. Correlations among the elements were sought. Apparently soot came early and coagulated with the ejecta, staying with them for the primary fallout and in the next 5 cm, but then parting company, perhaps due to size sorting.

Shock-induced vaporization of anhydrite and global cooling from the K/T impact

NASA Astrophysics Data System (ADS)

Gupta, Satish C.; Ahrens, Thomas J.; Yang, Wenbo

2001-06-01

Discovery of abundant anhydrite (CaSO 4) and gypsum (CaSO 4·2H 2O) in the otherwise carbonate sediment comprising the upper 3 km thick layer of the target rock at the K/T impact site has prompted research on these minerals. Evaluation of the severity of the proposed extinction mechanism involving injection of impact-generated SO 2 and SO 3 into the stratosphere entails determination of criteria for shock-induced vaporization of these minerals. In the present work we present new data on the vaporization criteria of anhydrite. These are based on the reanalysis of the shock wave experiments of Yang and Ahrens [Earth Planet. Sci. Lett. 156 (1998) 125-140], conducted on material with 30% porosity, in which the shock- (fully or partially) vaporized sample interacts with an overlying LiF window. The velocity histories, monitored using a velocity interferometer, are compared with numerical simulations employing an improved equation of state for porous anhydrite and its vaporization products. We also employ the 'entropy criterion' for vaporization of material under shock compression. The values of the entropies of incipient and complete vaporization for anhydrite are determined to be 1.65±0.12 and 3.17±0.12 kJ (kg K) -1, respectively, and the corresponding pressures for incipient and the complete vaporization along the Hugoniot for the solid material are 32.5±2.5 and 122±13 GPa, respectively as compared with 81±7 and 155±13 GPa previously reported by Yang and Ahrens. Along with these criteria, the use of the recent estimate of diameter (100 km) for the Chicxulub transient crater [O'Keefe and Ahrens, J. Geophys. Res. 104 (E11) (1999) 27091-27104; Morgan et al., Nature 390 (1997) 472-476] that is smaller than previously assumed, along with Ivanov et al.'s [Geol. Soc. Am. Spec. Pap. 307 (1996) 125-142] 2-D hydrodynamic simulation to determine the shock attenuation and Pope et al.'s [J. Geophys. Res., 102 (E9) (1997) 21645-21664] radiative transfer model, yields the

Shocked quartz and more: Impact signatures in K-T boundary clays and claystones

NASA Technical Reports Server (NTRS)

Bohor, Bruce F.

1988-01-01

Quartz grains displaying multiple sets of planar features are described from numerous Cretaceous-Tertiary (K-T) boundary clays and claystones at both marine and nonmarine depositional sites around the world. All these sites also show anomalously high amounts of iridium and enrichments of other siderophile elements in cosmic ratios within these boundary units. This combination of mineralogical and geochemical features are used in support of an impact hypothesis for the end-Cretaceous event. Recently, it was suggested that some combination of explosive and nonexplosive volcanism associated with the formation of the Deccan traps in India could be responsible for the mineralogy and geochemistry seen in the K-T boundary units. Besides the obvious contradition of simultaneous explosive and nonexplosive volcanism from one locality during an instant of geologic time, there remains the difficulty of spreading both iridium (and trace elements in cosmic proportions) and quartz grains around the world by volcanic (atmospheric) transport. In addition, the ability of volcanism to produce the type of shock metamorphism seen in minerals at the K-T boundary was not demonstrated. Multiple sets of shock lamellae in quartz are considered characteristic of shock metamorphism in rocks at the sites of known impact craters and are the type of deformation seen in quartz from K-T boundary clays and claystones. Single sets of poorly defined lamellae described from rare quartz grains in certain volcanic deposits are characteristic of tectonic deformation and do not correspond to the shock lamellae in quartz from K-T sediments and impact structures. So-called shock mosaicism in quartz and feldspar grains described from volcanic deposits can result from many processes other than shock metamorphism, and therefore is not considered to be an effect characteristic solely of shock. The mineralogy of shock-metamorphosed grains at the K-T boundary also argues against a volcanic origin.

2 kWe Solar Dynamic Ground Test Demonstration Project. Volume 1; Executive Summary

NASA Technical Reports Server (NTRS)

Alexander, Dennis

1997-01-01

The Solar Dynamic Ground Test Demonstration (SDGTD) successfully demonstrated a solar-powered closed Brayton cycle system in a relevant space thermal environment. In addition to meeting technical requirements the project was completed 4 months ahead of schedule and under budget. The following conclusions can be supported: 1. The component technology for solar dynamic closed Brayton cycle technology has clearly been demonstrated. 2. The thermal, optical, control, and electrical integration aspects of systems integration have also been successfully demonstrated. Physical integration aspects were not attempted as these tend to be driven primarily by mission-specific requirements. 3. System efficiency of greater than 15 percent (all losses fully accounted for) was demonstrated using equipment and designs which were not optimized. Some preexisting hardware was used to minimize cost and schedule. 4. Power generation of 2 kWe. 5. A NASA/industry team was developed that successfully worked together to accomplish project goals. The material presented in this report will show that the technology necessary to design and fabricate solar dynamic electrical power systems for space has been successfully developed and demonstrated. The data will further show that achieved results compare well with pretest predictions. The next step in the development of solar dynamic space power will be a flight test.

Interface-induced superconductivity at ∼25 K at ambient pressure in undoped CaFe2As2 single crystals

PubMed Central

Zhao, Kui; Lv, Bing; Deng, Liangzi; Huyan, Shu-Yuan; Xue, Yu-Yi; Chu, Ching-Wu

2016-01-01

Superconductivity has been reversibly induced/suppressed in undoped CaFe2As2 (Ca122) single crystals through proper thermal treatments, with Tc at ∼25 K at ambient pressure and up to 30 K at 1.7 GPa. We found that Ca122 can be stabilized in two distinct tetragonal (T) phases at room temperature and ambient pressure: PI with a nonmagnetic collapsed tetragonal (cT) phase at low temperature and PII with an antiferromagnetic orthorhombic (O) phase at low temperature, depending on the low-temperature annealing condition. Neither phase at ambient pressure is superconducting down to 2 K. However, systematic annealing for different time periods at 350 °C on the as-synthesized crystals, which were obtained by quenching the crystal ingot from 850 °C, reveals the emergence of superconductivity over a narrow time window. Whereas the onset Tc is insensitive to the anneal time, the superconductive volume fraction evolves with the time in a dome-shaped fashion. Detailed X-ray diffraction profile analyses further reveal mesoscopically stacked layers of the PI and the PII phases. The deduced interface density correlates well with the superconducting volume measured. The transport anomalies of the T–cT transition, which is sensitive to lattice strain, and the T–O transition, which is associated with the spin-density-wave (SDW) transition, are gradually suppressed over the superconductive region, presumably due to the interface interactions between the nonmagnetic metallic cT phase and the antiferromagnetic O phase. The results provide the most direct evidence to date for interface-enhanced superconductivity in undoped Ca122, consistent with the recent theoretical prediction. PMID:27799564

The tumor suppressor SirT2 regulates cell cycle progression and genome stability by modulating the mitotic deposition of H4K20 methylation

USDA-ARS?s Scientific Manuscript database

The establishment of the epigenetic mark H4K20me1 (monomethylation of H4K20) by PR-Set7 during G2/M directly impacts S-phase progression and genome stability. However, the mechanisms involved in the regulation of this event are not well understood. Here we show that SirT2 regulates H4K20me1 depositi...

Simultaneous observations of Ca II K and Mg II k in T Tauri stars

NASA Technical Reports Server (NTRS)

Calvet, N.; Basri, G.; Imhoff, C. L.; Giampapa, M. S.

1985-01-01

The first simultaneous, calibrated observations of the Ca II K and Mg II k resonance lines in T Tauri stars are presented. It is found that for T Tauri stars with mass greater than 1.5 solar mass, which have radiative cores and tend to be fast rotators, the k line seems to arise in an extended region (probably also responsible for the H-alpha emission), whereas the K line apparently originates closer to the highly inhomogeneous stellar surface. The lower mass stars, which are fully convective and tend to be slow rotators, are more easily described by a largely chromospheric model, consistent with main-sequence activity structures but at greater values of the nonradiative flux. The strongest emission-line stars in the low-mass group, however, are also likely to have extended k line regions.

Leucine increases mucin 2 and occludin production in LS174T cells partially via PI3K-Akt-mTOR pathway.

PubMed

Mao, Xiangbing; Hu, Haiyan; Tang, Jun; Chen, Daiwen; Yu, Bing

2016-09-01

Mucin 2 and occludin play a crucial role in preserving the intestinal mucosal integrity. However, the role for leucine mediating intestinal mucin 2 and occludin expression has little been investigated. The current study was conducted to test the hypothesis that leucine treatment could increase mucin 2 and occludin levels in LS174T cells. The LS174T cells were incubated in the Dulbecco's Modified Eagle Medium (DMEM) supplementing 0, 0.5 and 5 mmol/L L-leucine for the various durations. Two hours after the leucine treatment, the inhibitor of mammalian target of rapamycin (mTOR) and protein kinase B (Akt) phosphorylation in LS174T cells were significantly increased ( P  < 0.05), and the mucin 2 and occludin levels were also significantly enhanced ( P  < 0.05). However, the pretreatment of 10 nmol/L rapamycin, which was an mTOR inhibitor, or 1 μmol/L wortmanin, which was an inhibitor of phosphatidylinositol 3-kinase (PI3K), completely inhibited leucine-induced mTOR or Akt phosphorylation ( P  < 0.05), and significantly reduced leucine-stimulated mucin 2 and occludin levels ( P  < 0.05). These results suggest that leucine treatment promotes the mucin 2 and occludin levels in LS174T cells partially through the PI3K-Akt-mTOR signaling pathway.

Obtaining T1-T2 distribution functions from 1-dimensional T1 and T2 measurements: The pseudo 2-D relaxation model

NASA Astrophysics Data System (ADS)

Williamson, Nathan H.; Röding, Magnus; Galvosas, Petrik; Miklavcic, Stanley J.; Nydén, Magnus

2016-08-01

We present the pseudo 2-D relaxation model (P2DRM), a method to estimate multidimensional probability distributions of material parameters from independent 1-D measurements. We illustrate its use on 1-D T1 and T2 relaxation measurements of saturated rock and evaluate it on both simulated and experimental T1-T2 correlation measurement data sets. Results were in excellent agreement with the actual, known 2-D distribution in the case of the simulated data set. In both the simulated and experimental case, the functional relationships between T1 and T2 were in good agreement with the T1-T2 correlation maps from the 2-D inverse Laplace transform of the full 2-D data sets. When a 1-D CPMG experiment is combined with a rapid T1 measurement, the P2DRM provides a double-shot method for obtaining a T1-T2 relationship, with significantly decreased experimental time in comparison to the full T1-T2 correlation measurement.

Extraction of t slopes from experimental γ p →K+Λ and γ p →K+Σ0 cross section data

NASA Astrophysics Data System (ADS)

Freese, Adam; Puentes, Daniel; Adhikari, Shankar; Badui, Rafael; Guo, Lei; Raue, Brian

2017-10-01

We analyze recent K+ meson photoproduction data from the CLAS collaboration for the reactions γ p →K+Λ and γ p →K+Σ0 , fitting measured forward-angle differential cross sections to the form A eB t . We develop a quantitative scheme for determining the kinematic region where the fit is to be done, and, from the extracted t -slope B , determine whether single-Reggeon exchange can explain the production mechanism. We find that, in the region 5 2 , production of the K+Λ channel can be explained by single K+ Reggeon exchange, but the K+Σ0 production channel cannot. We verify these conclusions by fitting the data to a differential cross section produced by the interfering sum of two exponential amplitudes.