Finite-connectivity spin-glass phase diagrams and low-density parity check codes.

PubMed

Migliorini, Gabriele; Saad, David

2006-02-01

We obtain phase diagrams of regular and irregular finite-connectivity spin glasses. Contact is first established between properties of the phase diagram and the performance of low-density parity check (LDPC) codes within the replica symmetric (RS) ansatz. We then study the location of the dynamical and critical transition points of these systems within the one step replica symmetry breaking theory (RSB), extending similar calculations that have been performed in the past for the Bethe spin-glass problem. We observe that the location of the dynamical transition line does change within the RSB theory, in comparison with the results obtained in the RS case. For LDPC decoding of messages transmitted over the binary erasure channel we find, at zero temperature and rate , an RS critical transition point at while the critical RSB transition point is located at , to be compared with the corresponding Shannon bound . For the binary symmetric channel we show that the low temperature reentrant behavior of the dynamical transition line, observed within the RS ansatz, changes its location when the RSB ansatz is employed; the dynamical transition point occurs at higher values of the channel noise. Possible practical implications to improve the performance of the state-of-the-art error correcting codes are discussed.

Masses and ages of Delta Scuti stars in eclipsing binary systems

NASA Astrophysics Data System (ADS)

Tsvetkov, Ts. G.; Petrova, Ts. C.

1993-05-01

By using data mainly from Frolov et al. (1982) for four Delta Scuti stars in eclipsing binary systems, AB Cas, Y Cam, RS Cha, and AI Hya, their physical parameters, distances, and radial pulsation modes are determined. The evolutionary track systems of Iben (1967), Paczynski (1970), and Maeder and Meynet (1988) are interpolated in order to estimate evolutionary masses Me and ages t of these variables. Their pulsation masses MQ are estimated from the fitting formulae of Faulkner (1977) and Fitch (1981). Our estimates of evolutionary masses M(e) and pulsation masses M(Q) are close to the masses M determined by Frolov et al. from the star binarity. The only exception is AB Cas, for which there is no agreement between certain star parameters. Another, independent approach is also applied to the stars RS Cha and AI Hya: by using their photometric indices b - y and c(1) from the catalog of Lopez de Coca et al. (1990) and appropriate photometric calibrations, other sets of physical parameters, distances, modes, ages, and evolutionary and pulsation masses of both variables are obtained.

Period changes of the sample of eclipsing binaries with active chromospheres

NASA Astrophysics Data System (ADS)

Jableka, D.; Zola, S.; Zakrzewski, B.; Szymanski, T.; Kuzmicz, A.; de Villiers, S. N.; Zejda, M.; Koziel-Wierzbowska, D.

2012-11-01

In this work we present results derived from analysis of the O-C behaviour of ten eclipsing binary systems: AR Lac, CG Cyg, HP Aur, MM Her, RS CVn, RT And, SV Cam, V471 Tau, WW Dra and CF Tuc. It was proved on the basis of moments of minima compiled from the literature and new ones determined from recent observations, that these binaries show long term (19-91 years) modulations of their orbital periods, clearly visible in their O-C diagrams. Two possible explanations for this effect are considered: (1) the light-travel time effect due to the presence of a third body orbiting the eclipsing systems; (2) the Applegate mechanism predicting period modulation by changes in the distribution of angular momentum as a star goes through its activity cycles. It was found that in the case of four systems the existence of a third star, orbiting the binary, is a more plausible explanation of observations.

MM Herculis - An eclipsing binary of the RS CVn

NASA Technical Reports Server (NTRS)

Sowell, J. R.; Hall, D. S.; Henry, G. W.; Burke, E. W., Jr.; Milone, E. F.

1983-01-01

V, B and U differential photoelectric photometry has been obtained for the RS Canum Venaticorum-class eclipsing binary star MM Her, with the light outside the eclipse being Fourier-analyzed to study wave migration and amplitude. These, together with the mean light level of the system, have been monitored from 1976 through 1980. Observations within the eclipse have revealed eclipses to be partial, rather than total as previously thought. The geometric elements of the presently rectified light curve are forced on the pre-1980 light curves and found to be compatible. With these elements, and previously obtained double line radial velocity curves, new absolute dimensions of 1.18 solar masses and 1.58 solar radii are calculated for the hotter star and 1.27 solar masses and 2.83 solar radii for the cooler star. The plotting of color indices on the color-color curve indicates G2V and K2IV spectral types.

Phase behaviour, interactions, and structural studies of (amines+ionic liquids) binary mixtures.

PubMed

Jacquemin, Johan; Bendová, Magdalena; Sedláková, Zuzana; Blesic, Marijana; Holbrey, John D; Mullan, Claire L; Youngs, Tristan G A; Pison, Laure; Wagner, Zdeněk; Aim, Karel; Costa Gomes, Margarida F; Hardacre, Christopher

2012-05-14

We present a study on the phase equilibrium behaviour of binary mixtures containing two 1-alkyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide-based ionic liquids, [C(n)mim] [NTf(2)] (n=2 and 4), mixed with diethylamine or triethylamine as a function of temperature and composition using different experimental techniques. Based on this work, two systems showing an LCST and one system with a possible hourglass shape are measured. Their phase behaviours are then correlated and predicted by using Flory-Huggins equations and the UNIQUAC method implemented in Aspen. The potential of the COSMO-RS methodology to predict the phase equilibria was also tested for the binary systems studied. However, this methodology is unable to predict the trends obtained experimentally, limiting its use for systems involving amines in ionic liquids. The liquid-state structure of the binary mixture ([C(2)mim] [NTf(2)]+diethylamine) is also investigated by molecular dynamics simulation and neutron diffraction. Finally, the absorption of gaseous ethane by the ([C(2)mim][NTf(2)]+diethylamine) binary mixture is determined and compared with that observed in the pure solvents. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The enigmatic star EZ Pegasi - A mystery solved?

NASA Technical Reports Server (NTRS)

Howell, S. B.; Bopp, B. W.

1985-01-01

EZ Peg, a ninth-magnitude G star that has been classified by various authors as an irregular variable, a U Gem system, and a contact binary, is shown to have all the spectroscopic and photometric characteristics of an active-chromosphere RS CVn binary. It is suggested that the reported outburst of 1943, when the spectrum appeared to be that of a B star, never occurred. The strong Ca II H and K reversals, viewed with low spectral resolution, caused the photospheric Ca II absorption to appear abnormally weak, mimicking a much earlier spectral type.

VizieR Online Data Catalog: Excess CaII H&K emission in active binaries (Montes+, 1996)

NASA Astrophysics Data System (ADS)

Montes, D.; Fernandez-Figueroa, M. J.; Cornide, M.; de Castro, E.

1996-05-01

In this work we analyze the behaviour of the excess CaII H & K and H_epsilon emissions in a sample of 73 chromospherically active binary systems (RS CVn and BY Dra classes), of different activity levels and luminosity classes. This sample includes the 53 stars analyzed by Fernandez-Figueroa et al. (1994) and the observations of 28 systems described by Montes et al. (1995). By using the spectral subtraction technique (subtraction of a synthesized stellar spectrum constructed from reference stars of spectral type and luminosity class similar to those of the binary star components) we obtain the active-chromosphere contribution to the CaII H & K lines in these 73 systems. We have determined the excess CaII H & K emission equivalent widths and converted them into surface fluxes. The emissions arising from each component were obtained when it was possible to deblend both contributions. (4 data files).

Models for 60 double-lined binaries containing giants

NASA Astrophysics Data System (ADS)

Eggleton, Peter P.; Yakut, Kadri

2017-07-01

The observed masses, radii and temperatures of 60 medium- to long-period binaries, most of which contain a cool, evolved star and a hotter less evolved one, are compared with theoretical models which include (a) core convective overshooting, (b) mass-loss, possibly driven by dynamo action as in RS CVn binaries, and (c) tidal friction, including its effect on orbital period through magnetic braking. A reasonable fit is found in about 42 cases, but in 11 other cases the primaries appear to have lost either more mass or less mass than the models predict, and in 4 others the orbit is predicted to be either more or less circular than observed. Of the remaining three systems, two (γ Per and HR 8242) have a markedly 'overevolved' secondary, our explanation being that the primary component is the merged remnant of a former short-period sub-binary in a former triple system. The last system (V695 Cyg) defies any agreement at present. Mention is also made of three other systems (V643 Ori, OW Gem and V453 Cep), which are relevant to our discussion.

Numerical determination of the interfacial energy and nucleation barrier of curved solid-liquid interfaces in binary systems

NASA Astrophysics Data System (ADS)

Kundin, Julia; Choudhary, Muhammad Ajmal

2016-07-01

The phase-field crystal (PFC) technique is a widely used approach for modeling crystal growth phenomena with atomistic resolution on mesoscopic time scales. We use a two-dimensional PFC model for a binary system based on the work of Elder et al. [Phys. Rev. B 75, 064107 (2007), 10.1103/PhysRevB.75.064107] to study the effect of the curved, diffuse solid-liquid interface on the interfacial energy as well as the nucleation barrier. The calculation of the interfacial energy and the nucleation barrier certainly depends on the proper definition of the solid-liquid dividing surface and the corresponding nucleus size. We define the position of the sharp interface at which the interfacial energy is to be evaluated by using the concept of equimolar dividing surface (re) and the minimization of the interfacial energy (rs). The comparison of the results based on both radii shows that the difference re-rs is always positive and has a limit for large cluster sizes which is comparable to the Tolman length. Furthermore, we found the real nucleation barrier for small cluster sizes, which is defined as a function of the radius rs, and compared it with the classical nucleation theory. The simulation results also show that the extracted interfacial energy as function of both radii is independent of system size, and this dependence can be reasonably described by the nonclassical Tolman formula with a positive Tolman length.

The Spot Variability and Related Brightness variations of the Solar Type PreContact W UMa Binary System V1001 Cas

NASA Astrophysics Data System (ADS)

Samec, Ronald George; Koenke, Sam S.; Faulkner, Danny R.

2015-08-01

A new classification of eclipsing binary has emerged, Pre Contact WUMa Binaries (PCWB’s, Samec et al. 2012). These solar-type systems are usually detached or semidetached with one or both components under filling their critical Roche lobes. They usually have EA or EB-type light curves (unequal eclipse depths, indicating components with substantially different temperatures). The accepted scenario for these W UMa binaries is that they are undergoing steady but slow angular momentum losses due to magnetic braking as stellar winds blow radially away on stiff bipolar field lines. These binaries are believed to come into stable contact and eventually coalesce into blue straggler type, single, fast rotating A-type stars (Guinan and Bradstreet,1988). High precision 2012 and 2009 light curves are compared for the very short period (~0.43d) Precontact W UMa Binary (PCWB), V1001 Cassiopeia. This is the shortest period PCWB found so far. Its short period, similar to the majority of W UMa’s, in contrast to its distinct Algol-type light curve, make it a very rare and interesting system. Our solutions of light curves separated by some three years give approximately the same physical parameters. However the spots radically change, in temperature, area and position causing a distinctive variation in the shape of the light curves. We conclude that spots are very active on this solar type dwarf system and that it may mimic its larger cousins, the RS CVn binaries.

The Shape of Near-Earth Asteroid 275677 (2000 RS11) From Inversion of Arecibo and Goldstone Radar Images

NASA Astrophysics Data System (ADS)

Brauer, Kaley; Busch, Michael W.; Benner, Lance A. M.; Brozovic, Marina; Howell, Ellen S.; Nolan, Michael C.; Springmann, Alessondra; Giorgini, Jon D.; Taylor, Patrick A.; Jao, Joseph S.

2015-11-01

We observed near-Earth asteroid 2000 RS11 with the Arecibo and Goldstone planetary radars during a 0.035 au approach in March 2014, obtaining delay-Doppler images between March 13 and March 17. The finest-resolution images have range resolution of 7.5 m/pixel and show that RS11 is a contact binary with complex topography. We used the SHAPE software package (Magri et al., Icarus 186, 156-160 2007) to create a physical model of RS11 and its spin state from these delay-Doppler images.The rotation period of RS11 is well constrained from optical lightcurves, P = 4.444 ± 0.001 h (Warner et al., Minor Planet Bulletin 41, 160; 2014 and Benishek, Minor Planet Bulletin 41, 257; 2014). We found two possible pole directions and corresponding shape models, mirror images of one another, which provide equally good fits to the radar data. RS11’s pole direction is either (λ , β) = (155°, 30°) ± 10° or (335°, -30°) ± 10° in J2000 ecliptic coordinates. The most likely pole directions of RS11 are not aligned with the heliocentric orbit normal and instead have an obliquity within 10° of 56° or 124°.Our best-fit shape models are 1400-vertex polyhedra comprising two lobes in contact. The lengths of RS11’s principal axes are 698 ± 71 m, 578 ± 59 m, and 758 ± 77 m. RS11 has a volume of 0.086 ± 0.026 km^3. The long axis of RS11’s larger lobe is 751 ± 77 m and the long axis of the smaller lobe is 398 ± 41 m; the volume ratio between these lobes is roughly 2.7 ± 10%. Spectral data informs us that RS11 is an S-class object (Lazzarin et al., Icarus 169, 379; 2004).RS11's shape is unusual compared with those of other contact binary NEAs imaged by radar. Its larger lobe is flattened. Additionally, while the neck between the smaller and larger lobes of most contact binaries is located near the larger lobe's longest principal axis (such as in the cases of 25143 Itokawa and 4179 Toutatis), RS11's neck is near its larger lobe's shortest principal axis. RS11 is the first asteroid of this type for which we have a shape model.

Orbital variability in the eclipsing pulsar binary PSR B1957+20

NASA Technical Reports Server (NTRS)

Arzoumanian, Z.; Fruchter, A. S.; Taylor, J. H.

1994-01-01

We have conducted timing observations of the eclipsing millisecond binary pulsar PSR B1957+20, extending the span of data on this pulsar to more than five years. During this time the orbital period of the system has varied by roughly Delta P(sub b)/P(sub b) = 1.6 x 10(exp -7), changing quardratically with time and displaying with time and displaying an orbital period second derivative of P(sub b) = (1.43 +/- 0.08) x 10(exp -18)/sec. The previous measurement of a large negative orbital period derivative reflected only the short-term behavior of the system during the early observations; the orbital period derivative is now positive. If, as we suspect, the PSR B1957+20 system is undergoing quasi-cyclic orbital period variations similar to those found in other close binaries such as Algol and RS CVn, then the 0.025 solar mass companion to PSR B1957+20 is most likely non-degenerate, convective, and magnetically active.

Infrared observations of RS CVn stars

NASA Technical Reports Server (NTRS)

Berriman, G.; De Campli, W. M.; Werner, M. W.; Hatchett, S. P.

1983-01-01

The paper presents infrared photometry of the RS CVn binary stars AR Lac (1.2-10 microns) and MM Her (1.2-3.5 microns) as they egressed from their primary and secondary eclipses; of the eclipsing systems RS CVn and Z Her at maximum light (1.2-10 microns) and of the non-eclipsing systems UX Ari and HR 1099 (1.2-10 microns). An analysis of these and published V data based on flux ratio diagrams (linear analogues of color-color diagrams) shows that G and K stars supply the infrared light of these systems. In AR Lac, the combined light of a G5-K0 subgiant and either a late F dwarf or an early F subgiant can account for the observed visual and infrared light curves. None of these systems shows infrared emission from circumstellar matter. This result is simply understood: dust grains would not be expected to form in the physical conditions surrounding the subgiant, and the corona and chromosphere (whose properties have been deduced from spectroscopic X-ray observations) should not produce appreciable infrared emission.

The first eclipsing binary catalogue from the MOA-II data base

NASA Astrophysics Data System (ADS)

Li, M. C. A.; Rattenbury, N. J.; Bond, I. A.; Sumi, T.; Bennett, D. P.; Koshimoto, N.; Abe, F.; Asakura, Y.; Barry, R.; Bhattacharya, A.; Donachie, M.; Evans, P.; Freeman, M.; Fukui, A.; Hirao, Y.; Itow, Y.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Muraki, Y.; Nagakane, M.; Ohnishi, K.; Saito, To.; Sharan, A.; Sullivan, D. J.; Suzuki, D.; Tristram, P. J.; Yonehara, A.

2017-09-01

We present the first catalogue of eclipsing binaries in two MOA (Microlensing Observations in Astrophysics) fields towards the Galactic bulge, in which over 8000 candidates, mostly contact and semidetached binaries of periods <1 d, were identified. In this paper, the light curves of a small number of interesting candidates, including eccentric binaries, binaries with noteworthy phase modulations and eclipsing RS Canum Venaticorum type stars, are shown as examples. In addition, we identified three triple object candidates by detecting the light-travel-time effect in their eclipse time variation curves.

A catalogue of chromospherically active binary stars (third edition)

NASA Astrophysics Data System (ADS)

Eker, Z.; Ak, N. Filiz; Bilir, S.; Doǧru, D.; Tüysüz, M.; Soydugan, E.; Bakış, H.; Uǧraş, B.; Soydugan, F.; Erdem, A.; Demircan, O.

2008-10-01

The catalogue of chromospherically active binaries (CABs) has been revised and updated. With 203 new identifications, the number of CAB stars is increased to 409. The catalogue is available in electronic format where each system has a number of lines (suborders) with a unique order number. The columns contain data of limited numbers of selected cross references, comments to explain peculiarities and the position of the binarity in case it belongs to a multiple system, classical identifications (RS Canum Venaticorum, BY Draconis), brightness and colours, photometric and spectroscopic data, a description of emission features (CaII H and K, Hα, ultraviolet, infrared), X-ray luminosity, radio flux, physical quantities and orbital information, where each basic entry is referenced so users can go to the original sources.

VizieR Online Data Catalog: Chromospherically Active Binaries. Third version (Eker+, 2008)

NASA Astrophysics Data System (ADS)

Eker, Z.; Filiz-Ak, N.; Bilir, S.; Dogru, D.; Tuysuz, M.; Soydugan, E.; Bakis, H.; Ugras, B.; Soydugan, F.; Erdem, A.; Demircan, O.

2008-06-01

Chromospherically Active Binaries (CAB) catalogue have been revised and updated. With 203 new identifications, the number of CAB stars is increased to 409. Catalogue is available in electronic format where each system has various number of lines (sub-orders) with a unique order number. Columns contain data of limited number of selected cross references, comments to explain peculiarities and position of the binarity in case it belongs to a multiple system, classical identifications (RS CVn, BY Dra), brightness and colours, photometric and spectroscopic data, description of emission features (Ca II H&K, Hα, UV, IR), X-Ray luminosity, radio flux, physical quantities and orbital information, where each basic entry are referenced so users can go original sources. (10 data files).

A Period-Activity Relation for Active RS CVN Stars

NASA Astrophysics Data System (ADS)

Simon, Theodore

Soft X ray observations of RS CVn binaries point to a correlation between L x /Lbol (the X ray to bolometric luminosity ratio that measures the coronal heating rate) and Omega (the stellar angular velocity). This correlation is almost certainly caused by a stellar dynamo, operating in rapidly-rotating late-type stars with deep convection zones. We are proposing to extend the X ray "rotation-activity relation" to the uv transition region and chromospheric emission lines observable with IUE. If the non-radiative heating rates of stellar transition regions and chromospheres are determined largely by magnetic processes associated with a stellar dynamo, then a similar correlation may be found. We have selected a group of recently discovered active long-period systems, which we believe will be very bright at uv wavelengths. One important goal of this program is to determine whether past studies of the "rotation-activity connection" have been compromised by the omission of active long-period RS CVn systems.

Binaries and triples among asteroid pairs

NASA Astrophysics Data System (ADS)

Pravec, Petr; Scheirich, Peter; Kušnirák, Peter; Hornoch, Kamil; Galád, Adrián

2015-08-01

Despite major achievements obtained during the past two decades, our knowledge of the population and properties of small binary and multiple asteroid systems is still far from advanced. There is a numerous indirect evidence for that most small asteroid systems were formed by rotational fission of cohesionless parent asteroids that were spun up to the critical frequency presumably by YORP, but details of the process are lacking. Furthermore, as we proceed with observations of more and more binary and paired asteroids, we reveal new facts that substantially refine and sometimes change our understanding of the asteroid systems. One significant new finding we have recently obtained is that primaries of many asteroid pairs are actually binary or triple systems. The first such case found is (3749) Balam (Vokrouhlický, ApJL 706, L37, 2009). We have found 9 more binary systems among asteroid pairs within our ongoing NEOSource photometric project since October 2012. They are (6369) 1983 UC, (8306) Shoko, (9783) Tensho-kan, (10123) Fideoja, (21436) Chaoyichi, (43008) 1999 UD31, (44620) 1999 RS43, (46829) 1998 OS14 and (80218) 1999 VO123. We will review their characteristics. These paired binaries as we call them are mostly similar to binaries in the general ("background") population (of unpaired asteroids), but there are a few trends. The paired binaries tend to have larger secondaries with D_2/D_1 = 0.3 to 0.5 and they also tend to be wider systems with 8 of the 10 having orbital periods between 30 and 81 hours, than average among binaries in the general population. There may be also a larger fraction of triples; (3749) Balam is a confirmed triple, having a larger close and a smaller distant satellite, and (8306) Shoko and (10123) Fideoja are suspect triples as they show additional rotational lightcurve components with periods of 61 and 38.8 h that differ from the orbital period of 36.2 and 56.5 h, respectively. The unbound secondaries tend to be of the same size or smaller (with one exception) than the bound orbiting secondaries. I will compare the observed properties of the paired binaries to predictions from theories of formation of asteroid binaries and pairs.

The most plausible explanation of the cyclic period changes in close binaries: the case of the RS CVn-type binary WW Dra

NASA Astrophysics Data System (ADS)

Liao, W.-P.; Qian, S.-B.

2010-07-01

Cyclic period changes are a fairly common phenomenon in close binary systems and are usually explained as being caused either by the magnetic activity of one or both components or by the light travel time effect (LTTE) of a third body. We searched the orbital period changes in 182 EA-type (including the 101 Algol systems used by Hall), 43 EB-type and 53 EW-type binaries with known mass ratio and spectral type of the secondary component. We reproduced and improved the diagram in Hall according to the new collected data. Our plots do not support the conclusion derived by Hall that cyclic period changes are restricted to binaries having a secondary component with spectral type later than F5. The presence of period changes among systems with a secondary component of early type indicates that magnetic activity is one, but not the only, cause of the period variation. It is discovered that cyclic period changes, probably resulting from the presence of a third body, are more frequent in EW-type binaries among close systems. Therefore, the most plausible explanation of the cyclic period changes is the LTTE through the presence of a third body. Using the century-long historical record of the times of light minimum, we analysed the cyclic period change in the Algol binary WW Dra. It is found that the orbital period of the binary shows a ~112.2-yr cyclic variation with an amplitude of ~0.1977d. The cyclic oscillation can be attributed to the LTTE by means of a third body with a mass no less than 6.43Msolar. However, no spectral lines of the third body were discovered, indicating that it may be a candidate black hole. The third body is orbiting the binary at a distance closer than 14.4 au and may play an important role in the evolution of this system.

Binary weight distributions of some Reed-Solomon codes

NASA Technical Reports Server (NTRS)

Pollara, F.; Arnold, S.

1992-01-01

The binary weight distributions of the (7,5) and (15,9) Reed-Solomon (RS) codes and their duals are computed using the MacWilliams identities. Several mappings of symbols to bits are considered and those offering the largest binary minimum distance are found. These results are then used to compute bounds on the soft-decoding performance of these codes in the presence of additive Gaussian noise. These bounds are useful for finding large binary block codes with good performance and for verifying the performance obtained by specific soft-coding algorithms presently under development.

Coordinated XTE Observations of Coronal Structure and Flares on the Rs CVn Binary Sigma(sup 2) CrB

NASA Technical Reports Server (NTRS)

Brown, Alexander

1999-01-01

This NASA grant supported my RXTE observing and data analysis during AO2. The research involved a 100 kilosecond observation of the active RS CVn binary sigma(sup 2) CrB obtained on 1997 March 11-13. This observation covered two orbits of the binary (2.5 days elapsed time) as part of a coordinated satellite and ground-based study of coronal structure and flaring within this system. Simultaneous data was obtained from the ASCA X-ray satellite and the Very Large Array radio telescope. The one month of effort funded for the PI was used to calibrate and analyze the RXTE data. Additional research effort on this project to lead to a final publication has been provided from LTSA and GSRP grants. An initial attempt was made to calibrate the RXTE data in May 1997 but the results were disappointing with poor background subtraction leading to a relatively noisy PCA light curve. Subsequently major improvements have been made in the calibration techniques for low count rate PCA data and we returned to Goddard Space Flight Center in February 1999 when we were able to produce vastly better calibrated data. The RXTE results are currently being integrated with the ASCA and VLA data and a paper should be submitted by the end of summer 1999.

Two component X-ray emission from RS CVn binaries

NASA Technical Reports Server (NTRS)

Swank, J. H.; White, N. E.; Holt, S. S.; Becker, R. H.

1980-01-01

A summary of results from the solid state spectrometer on the Einstein Observatory for 7 RS CVn binaries is presented. The spectra of all require two emission components, evidenced by line emission characteristic of plasma at 4 to 8 x 10 to the 6th power and bremsstrahlung characteristic of 20 to 100 x 10 to the 6th power K. The data are interpreted in terms of magnetic coronal loops similar to those seen on the Sun, although with different characteristic parameters. The emission regions could be defined by separate magnetic structures. For pressure less than approximately 10 dynes/sq cm the low temperature plasma would be confined within the stellar radii, while the high temperature plasma would, for the synchronous close binaries, fill the binary orbits. However, for loop pressures exceeding 100 dynes/sq cm, the high temperature components would also be confined to within the stellar radii, in loops covering only small fractions of the stellar surfaces. While the radio properties and the occurrence of X-ray flares suggest the larger emission regions, the observations of time variations leave the ambiguity unresolved.

KOI-1003: A New Spotted, Eclipsing RS CVn Binary in the Kepler Field

NASA Astrophysics Data System (ADS)

Roettenbacher, Rachael M.; Kane, Stephen R.; Monnier, John D.; Harmon, Robert O.

2016-12-01

Using the high-precision photometry from the Kepler space telescope, thousands of stars with stellar and planetary companions have been observed. The characterization of stars with companions is not always straightforward and can be contaminated by systematic and stellar influences on the light curves. Here, through a detailed analysis of starspots and eclipses, we identify KOI-1003 as a new, active RS CVn star—the first identified with data from Kepler. The Kepler light curve of this close binary system exhibits the system’s primary transit, secondary eclipse, and starspot evolution of two persistent active longitudes. The near equality of the system’s orbital and rotation periods indicates the orbit and primary star’s rotation are nearly synchronized ({P}{orb}=8.360613+/- 0.000003 {days}; {P}{rot}˜ 8.23 {days}). By assuming the secondary star is on the main sequence, we suggest the system consists of a {1.45}-0.19+0.11 {M}⊙ subgiant primary and a {0.59}-0.04+0.03 {M}⊙ main-sequence companion. Our work gives a distance of 4400 ± 600 pc and an age of t={3.0}+2.0-0.5 {Gyr}, parameters which are discrepant with previous studies that included the star as a member of the open cluster NGC 6791.

Binary supersoft X-ray sources and the supernova Ia progenitor problem

NASA Astrophysics Data System (ADS)

Nelson, Thomas John

In this thesis I present a study of several binary supersoft X-ray sources in order to assess their properties and to determine whether they may be supernova Ia (SN Ia) progenitors. The first chapter is an introduction to the problem and the sources of interest. In the second and third chapters I present an X-ray spectroscopic study of the recurrent nova RS Ophiuchi (RS Oph) during and after its 2006 outburst, carried out with Chandra and XMM-Newton. I discuss the physical origins of the X-ray emission at each stage of the outburst and place the first direct constraints on the mass of the white dwarf, which is very close to the Chandrasekhar limit. I also show that the surface composition of the white dwarf during the supersoft phase is consistent with nuclear processed material, indicating that RS Oph retains mass after each outburst and is likely growing in mass with time, and is therefore a potential SN Ia progenitor. I discuss the lack of accretion signatures in the quiescent emission from RS Oph, which are at odds with the high frequency of nova outbursts, and explore the possibility that an alternative accretion model may account for the quiescent X-ray properties in the system. Finally, in the fourth chapter, I examine the supersoft X-ray source (SSS) population in the nearby galaxy M31 at X-ray, ultraviolet (UV) and optical wavelengths. I explore the long-term behavior of these objects, and find that a much smaller fraction are persistent or recurrent X-ray sources than in the Magellanic Clouds. I carry out a search for counterparts of the SSS using the Galactic Evolution Explorer (GALEX) satellite and the WIYN 3.5m telescope, and find that the majority of sources do not have any UV counterparts. For those that do, I find that the UV sources have properties consistent with young, massive stars in M31. I find indications that some SSS may be in high mass binaries. If these sources are nuclear burning white dwarfs, then they may be the progenitors of the SNe Ia that appear to be associated with recent star formation.

Observational constraints on the inter-binary stellar flare hypothesis for the gamma-ray bursts

NASA Astrophysics Data System (ADS)

Rao, A. R.; Vahia, M. N.

1994-01-01

The Gamma Ray Observatory/Burst and Transient Source Experiment (GRO/BATSE) results on the Gamma Ray Bursts (GRBs) have given an internally consistent set of observations of about 260 GRBs which have been released for analysis by the BATSE team. Using this database we investigate our earlier suggestion (Vahia and Rao, 1988) that GRBs are inter-binary stellar flares from a group of objects classified as Magnetically Active Stellar Systems (MASS) which includes flare stars, RS CVn binaries and cataclysmic variables. We show that there exists an observationally consistent parameter space for the number density, scale height and flare luminosity of MASS which explains the complete log(N) - log(P) distribution of GRBs as also the observed isotropic distribution. We further use this model to predict anisotropy in the GRB distribution at intermediate luminosities. We make definite predictions under the stellar flare hypothesis that can be tested in the near future.

Single nucleotide polymorphisms in the CD40 gene associate with the disease susceptibility and severity in knee osteoarthritis in the Chinese Han population: a case-control study.

PubMed

Deng, Zhen-Han; Sun, Ming-Hua; Li, Yu-Sheng; Luo, Wei; Zhang, Fang-Jie; Tian, Jian; Wu, Ping; Xiao, Wen-Feng

2017-03-21

This study explored the association between single nucleotide polymorphisms (SNPs) in the CD40 gene, rs4810485 G > T and rs1883832 C > T, as well as disease susceptibility and severity in knee osteoarthritis (KOA) in the Chinese Han population. Peripheral venous blood was collected from 133 KOA patients (KOA group) and 143 healthy people (control group) from December 2012 to November 2013. The patients in the KOA group were classified into mild, moderate and severe groups according to disease severity. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to test the genotypes of all subjects. Binary logistic regression analyses were performed to analyze the risk factors for KOA. The KOA group was significantly different from the control group in living environment (P < 0.05). The KOA group had a lower frequency of TT genotype and T allele distribution of rs4810485 G > T compared with the control group, and rs4810485 G > T TT genotype and T allele may associate with low incidence of KOA (all P < 0.05). Besides, T allele and mutant homozygous TT genotype of rs1883832 C > T increased the susceptibility to KOA. Genotype and allele distribution of rs4810485 G > T and rs1883832 C > T were significantly different among the mild, moderate and severe groups (P < 0.05). There were more patients with rs4810485 G > T GG genotype and rs1883832 C > T TT genotype in the severe group than other genotypes of these two SNPs. According to binary logistic regression analysis, rs4810485 G > T TT genotype could alleviate disease severity in KOA, rs1883832 C > T TT genotype increase the severity of KOA and living environment is an important external factor that affects KOA severity. These data provide evidences that rs4810485 G > T and rs1883832 C > T in the CD40 gene may be associated with disease susceptibility and severity in KOA.

Candidate genes for COPD in two large data sets.

PubMed

Bakke, P S; Zhu, G; Gulsvik, A; Kong, X; Agusti, A G N; Calverley, P M A; Donner, C F; Levy, R D; Make, B J; Paré, P D; Rennard, S I; Vestbo, J; Wouters, E F M; Anderson, W; Lomas, D A; Silverman, E K; Pillai, S G

2011-02-01

Lack of reproducibility of findings has been a criticism of genetic association studies on complex diseases, such as chronic obstructive pulmonary disease (COPD). We selected 257 polymorphisms of 16 genes with reported or potential relationships to COPD and genotyped these variants in a case-control study that included 953 COPD cases and 956 control subjects. We explored the association of these polymorphisms to three COPD phenotypes: a COPD binary phenotype and two quantitative traits (post-bronchodilator forced expiratory volume in 1 s (FEV₁) % predicted and FEV₁/forced vital capacity (FVC)). The polymorphisms significantly associated to these phenotypes in this first study were tested in a second, family-based study that included 635 pedigrees with 1,910 individuals. Significant associations to the binary COPD phenotype in both populations were seen for STAT1 (rs13010343) and NFKBIB/SIRT2 (rs2241704) (p<0.05). Single-nucleotide polymorphisms rs17467825 and rs1155563 of the GC gene were significantly associated with FEV₁ % predicted and FEV₁/FVC, respectively, in both populations (p<0.05). This study has replicated associations to COPD phenotypes in the STAT1, NFKBIB/SIRT2 and GC genes in two independent populations, the associations of the former two genes representing novel findings.

Tidal Synchronization and Differential Rotation of Kepler Eclipsing Binaries

NASA Astrophysics Data System (ADS)

Lurie, John C.; Vyhmeister, Karl; Hawley, Suzanne L.; Adilia, Jamel; Chen, Andrea; Davenport, James R. A.; Jurić, Mario; Puig-Holzman, Michael; Weisenburger, Kolby L.

2017-12-01

Few observational constraints exist for the tidal synchronization rate of late-type stars, despite its fundamental role in binary evolution. We visually inspected the light curves of 2278 eclipsing binaries (EBs) from the Kepler Eclipsing Binary Catalog to identify those with starspot modulations, as well as other types of out-of-eclipse variability. We report rotation periods for 816 EBs with starspot modulations, and find that 79% of EBs with orbital periods of less than 10 days are synchronized. However, a population of short-period EBs exists, with rotation periods typically 13% slower than synchronous, which we attribute to the differential rotation of high-latitude starspots. At 10 days, there is a transition from predominantly circular, synchronized EBs to predominantly eccentric, pseudosynchronized EBs. This transition period is in good agreement with the predicted and observed circularization period for Milky Way field binaries. At orbital periods greater than about 30 days, the amount of tidal synchronization decreases. We also report 12 previously unidentified candidate δ Scuti and γ Doradus pulsators, as well as a candidate RS CVn system with an evolved primary that exhibits starspot occultations. For short-period contact binaries, we observe a period-color relation and compare it to previous studies. As a whole, these results represent the largest homogeneous study of tidal synchronization of late-type stars.

Nonlinear, nonbinary cyclic group codes

NASA Technical Reports Server (NTRS)

Solomon, G.

1992-01-01

New cyclic group codes of length 2(exp m) - 1 over (m - j)-bit symbols are introduced. These codes can be systematically encoded and decoded algebraically. The code rates are very close to Reed-Solomon (RS) codes and are much better than Bose-Chaudhuri-Hocquenghem (BCH) codes (a former alternative). The binary (m - j)-tuples are identified with a subgroup of the binary m-tuples which represents the field GF(2 exp m). Encoding is systematic and involves a two-stage procedure consisting of the usual linear feedback register (using the division or check polynomial) and a small table lookup. For low rates, a second shift-register encoding operation may be invoked. Decoding uses the RS error-correcting procedures for the m-tuple codes for m = 4, 5, and 6.

[Activities of Space Telescope Science Institute with the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Dempsey, Robert C.; Neff, James E.; Strassmeier, Klaus G.; Linsky, Jeffrey L.

1998-01-01

A number of studies, especially in recent years with the Hubble Space Telescope's (HST) Goddard High Resolution Spectrograph (GHRS), have been presented on the UV line profiles of late-type stars. Generally, these consist of a few "snapshot" spectra of several different key diagnostic emission lines. From this it has become clear that many active stars possess non-gaussian line profiles. Unlike the case with AR Lac, observed with IUE, no assymetric profile has been clearly identified that results from an inhomogeneous surface temperature or density distribution. In 1993 we attempted to observe the RS CVn binary V711 Tau at several phases with the GHRS in a number of UV bandpasses in order to study profile variations as a function of phase. Unfortunately, scheduling problems, pointing errors, continuous flaring and the sparse and uneven phase sampling prevented us from achieving the primary goal. However, it is clear that a number of UV lines in the system, notably C IV, Si IV and Mg II show very extended emission out to several hundred km/s. The profiles were also clearly variable. Vilhu et al. (1997) and Walter et al. (1995) conducted a campaign on the rapidly rotating, single star AB Dor, where they observed C IV continuously for 14 hours. They found extended, non-gaussian emission in the C IV doublet and that Doppler images derived from these images were remarkably similar to the simultaneous spot-image. In a follow up study of V711 Tau we have observed another RS CVn with complete phase coverage in three key wavelength bandpasses, utilizing the ability of HST to observe some stars at high latitudes in uninterrupted fashion. Generally classified as an RS CVn, V824 Ara (HD 155555) consists of a G5 IV star in a short period orbit (P=ld.68) with a K0 V-IV companion. However, the system does not eclipse and therefore does not rigorously fit the Hall (1976) definition. There is also a visual M star companion (LDS587B) 33 arcsec away. The space velocities of the stars suggests that the binary is part of the young disk population which agrees with the high Li I lambda 6708 abundance. With the M star companion showing very high levels of activity it seems likely that the V824 Ara +LDS587B system is pre-main sequence. With rotational velocities of 37 km/s and 29 km/s for the G and K star components respectively, the system is very similar to V711 Tau. Photometric observations by Cutispoto (1993) show an amplitude, delta V approx. = 0.12 with a period equal to the orbital value derived by Pasquini et at. (1991). Dempsey et al. (1993a) found a PSPC X-ray luminosity of 2.74 x 10(exp 30)erg/s. Two-temperature coronal models were applied to the PSPC X-ray pulse-height spectra by Dempsey et al. (1993b). They found that the lower temperature component was consistent with the full sample of RS CVn binaries studied but that the hot component was slightly lower than the sample as a whole. Moderate Ca II H and K emission, filled in H alpha and radio emission are also consistent with this being a fairly active, short period binary system.

NICER and MAXI Observations of Two Large X-ray Flares from RS CVn Binaries

NASA Astrophysics Data System (ADS)

Drake, Stephen A.; Hamaguchi, Kenji; Corcoran, Michael Francis; Iwakiri, Wataru; Sasaki, Ryo; Kawai, Hiroki; Tsuboi, Yohko; Enoto, Teruaki; NICER Science Team

2018-01-01

NICER has observed two giant X-ray flares on the active binary systems, GT Mus and UX Ari, in response to their detections by the MAXI all-sky X-ray monitor onboard the ISS, with a delay of about a day in each case. The large effective area of the NICER X-ray optics means that high signal-to-noise spectra with more than 200,000 counts were obtained in relatively short exposures totaling less than an hour in each set of observations.MAXI detected a transient of 5.5 x 10^-10 erg/s/cm2 at the position of the active RS CVn binary GT Mus (G5/8 III + ?) early on 2017 July 19. NICER started its observations about 1 day later, and intermittently monitored the decay for the next 2.5 days, accumulating about 1,600 seconds exposure. The NICER light curve shows a smooth, gradual flux decline by a factor of two for the first 2 days, followed by an apparent flattening in the last half day. The dominant plasma temperature remained at ~40 million K during this period, suggesting an ongoing continuous heating during the decay phase.NICER also followed up another MAXI-detected flare in October 2017, this one from the nearby active system, UX Ari. NICER's X-ray spectrum shows clear neon and oxygen lines, while the emissionfrom iron ions is not as prominent as it is in most flares, implying an abundance of only ~10% solar which is significantly lower than previous inferred coronal Fe abundances for this star, although this result is dependent on the NICER gain correction.

The first Doppler images of the eclipsing binary SZ Piscium

NASA Astrophysics Data System (ADS)

Xiang, Yue; Gu, Shenghong; Cameron, A. Collier; Barnes, J. R.; Zhang, Liyun

2016-02-01

We present the first Doppler images of the active eclipsing binary system SZ Psc, based on the high-resolution spectral data sets obtained in 2004 November and 2006 September-December. The least-squares deconvolution technique was applied to derive high signal-to-noise profiles from the observed spectra of SZ Psc. Absorption features contributed by a third component of the system were detected in the LSD profiles at all observed phases. We estimated the mass and period of the third component to be about 0.9 M⊙ and 1283 ± 10 d, respectively. After removing the contribution of the third body from the least-squares deconvolved profiles, we derived the surface maps of SZ Psc. The resulting Doppler images indicate significant star-spot activities on the surface of the K subgiant component. The distributions of star-spots are more complex than that revealed by previous photometric studies. The cooler K component exhibited pronounced high-latitude spots as well as numerous low- and intermediate-latitude spot groups during the entire observing seasons, but did not show any large, stable polar cap, different from many other active RS CVn-type binaries.

Error control techniques for satellite and space communications

NASA Technical Reports Server (NTRS)

Costello, D. J., Jr.

1986-01-01

High rate concatenated coding systems with trellis inner codes and Reed-Solomon (RS) outer codes for application in satellite communication systems are considered. Two types of inner codes are studied: high rate punctured binary convolutional codes which result in overall effective information rates between 1/2 and 1 bit per channel use; and bandwidth efficient signal space trellis codes which can achieve overall effective information rates greater than 1 bit per channel use. Channel capacity calculations with and without side information performed for the concatenated coding system. Concatenated coding schemes are investigated. In Scheme 1, the inner code is decoded with the Viterbi algorithm and the outer RS code performs error-correction only (decoding without side information). In scheme 2, the inner code is decoded with a modified Viterbi algorithm which produces reliability information along with the decoded output. In this algorithm, path metrics are used to estimate the entire information sequence, while branch metrics are used to provide the reliability information on the decoded sequence. This information is used to erase unreliable bits in the decoded output. An errors-and-erasures RS decoder is then used for the outer code. These two schemes are proposed for use on NASA satellite channels. Results indicate that high system reliability can be achieved with little or no bandwidth expansion.

Einstein observations of selected close binaries and shell stars

NASA Technical Reports Server (NTRS)

Guinan, E. F.; Koch, R. H.; Plavec, M. J.

1984-01-01

Several evolved close binaries and shell stars were observed with the IPC aboard the HEAO 2 Einstein Observatory. No eclipsing target was detected, and only two of the shell binaries were detected. It is argued that there is no substantial difference in L(X) for eclipsing and non-eclipsing binaries. The close binary and shell star CX Dra was detected as a moderately strong source, and the best interpretation is that the X-ray flux arises primarily from the corona of the cool member of the binary at about the level of Algol-like or RS CVn-type sources. The residual visible-band light curve of this binary has been modeled so as to conform as well as possible with this interpretation. HD 51480 was detected as a weak source. Substantial background information from IUE and ground scanner measurements are given for this binary. The positions and flux values of several accidentally detected sources are given.

The RECONS Hunt for Intriguing Binaries in the Solar Neighborhood

NASA Astrophysics Data System (ADS)

Bean, J. L.; Henry, T. J.; Jao, W. C.; Subasavage, J. P.

2001-12-01

As part of an effort to characterize the Sun's neighbors, photometric research was carried out on two samples of low-mass stars known or suspected to lie within 25 parsecs of the Sun. Quality filtered optical photometric data (UBVRI) from published research were merged with recently released infrared data (JHK) from the Two Micron All Sky Survey (2MASS) to create comprehensive long baseline V-I or V-K colors for more than 1400 stars. These were then combined with parallaxes from the NStars Database to create color-absolute magnitude diagrams. The results of this research include increasing the breadth of the NStars Database by adding photometric data for over 1400 stars, and identifying intriguing multiple systems (close spectroscopic binaries, BY Dra types, RS CVn systems) as well as white dwarfs and evolved stars in the solar neighborhood. More than two dozen objects have been identified as probable new multiple systems from their positions above the main sequence. Additional investigations for these intriguing systems are planned, including observations made with the GSU CHARA Array to resolve very close binary systems. This research is a continuation of the work done by RECONS (Research Consortium on Nearby Stars) based at Georgia Sate U., Johns Hopkins U., and U. Virginia, and NASA's Nearby Stars Project (NStars).

Forming-free colossal resistive switching effect in rare-earth-oxide Gd2O3 films for memristor applications

NASA Astrophysics Data System (ADS)

Cao, Xun; Li, Xiaomin; Gao, Xiangdong; Yu, Weidong; Liu, Xinjun; Zhang, Yiwen; Chen, Lidong; Cheng, Xinhong

2009-10-01

The reproducible forming-free resistive switching (RS) behavior in rare-earth-oxide Gd2O3 polycrystalline thin film was demonstrated. The characteristic of this forming-free RS was similar to that of other forming-necessary binary RS materials except that its initial resistance starts from not the high resistance state (HRS) but the low resistance state (LRS). An ultrahigh resistance switching ratio from HRS to LRS of about six to seven orders of magnitude was achieved at a bias voltage of 0.6 V. Mechanism analysis indicated that the existence of metallic Gd in the Gd2O3 films plays an important role in the forming-free RS performance. Our work provides a novel material with interesting RS behavior, which is beneficial to deepen our understanding of the origin of RS phenomenon.

Photoelectric photometry of the RS CVn binary EI Eridani = HD 26337

NASA Technical Reports Server (NTRS)

Hooten, J. T.; Strassmeier, K. G.; Hall, D. S.; Barksdale, W. S., Jr.; Bertoglio, A.

1989-01-01

Differential UBV(RI)sub KC and UBVRI photometry of the RS CVn binary EI Eridani obtained during December 1987 and January 1988 at fourteen different observatories is presented. A combined visual bandpass light curve, corrected for systematic errors of different observatories, utilizes the photometric period of 1,945 days to produce useful results. The analysis shows the visual light curve to have twin maxima, separated by about 0.4 phase, and a full amplitude of approximately 0.06 mag for the period of observation, a smaller amplitude than reported in the past. The decrease in amplitude may be due to a decrease or homogenization of spot coverage. To fit the asymmetrical light curve, a starspot model would have to employ at least two spotted regions separated in longitude.

An Intense Polarized Radio Flare from AR Lac

NASA Astrophysics Data System (ADS)

Mutel, R. L.; Neff, J. E.; Bookbinder, J.; Pagano, I.

1992-12-01

We have detected an intense, highly circularly polarized radio flare from the close binary system AR Lacertae during a 4 day multi-wavelength observing campaign in 1991 December. The flare lasted more than 6 hours and was preceded by a strong CIV flare one day earlier. The peak circular polarization was 70%, 38%,and 39% RCP at 1.4, 4.9, and 8.4 GHz respectively, with ~ 15% LCP at 15 and 22 GHZ. The high degree of circular polarization over such a large time scale and frequency range is highly unusual compared with previously observed radio flares from RS CVn binaries. Given these unusual characteristics, it is difficult to interpret the radiation mechanism either as a result of gyrosynchrotron emission or a coherent process such as an electron cyclotron maser.

Association of Genetic Polymorphisms of Renin–Angiotensin–Aldosterone System-Related Genes with Arterio-Venous Fistula Malfunction in Hemodialysis Patients

PubMed Central

Chen, Yu-Wei; Wu, Yu-Te; Lin, Jhin-Shyaun; Yang, Wu-Chang; Hsu, Yung-Ho; Lee, Kuo-Hua; Ou, Shou-Ming; Chen, Yung-Tai; Shih, Chia-Jen; Lee, Pui-Ching; Chan, Chia-Hao; Chung, Ming-Yi; Lin, Chih-Ching

2016-01-01

Hemodialysis (HD) is the most commonly-used renal replacement therapy for patients with end-stage renal disease worldwide. Arterio-venous fistula (AVF) is the vascular access of choice for HD patients with lowest risk of infection and thrombosis. In addition to environmental factors, genetic factors may also contribute to malfunction of AVF. Previous studies have demonstrated the effect of genotype polymorphisms of angiotensin converting enzyme on vascular access malfunction. We conducted a multicenter, cross-sectional study to evaluate the association between genetic polymorphisms of renin-angiotensin-aldosterone system and AVF malfunction. Totally, 577 patients were enrolled. Their mean age was 60 years old and 53% were male. HD patients with AVF malfunction had longer duration of HD (92.5 ± 68.1 vs. 61.2 ± 51.9 months, p < 0.001), lower prevalence of hypertension (44.8% vs. 55.3%, p = 0.025), right-sided (31.8% vs. 18.4%, p = 0.002) and upper arm AVF (26.6% vs. 9.7%, p < 0.001), and higher mean dynamic venous pressure (DVP) (147.8 ± 28.3 vs. 139.8 ± 30.0, p = 0.021). In subgroup analysis of different genders, location of AVF and DVP remained significant clinical risk factors of AVF malfunction in univariate and multivariate binary logistic regression in female HD patients. Among male HD patients, univariate binary logistic regression analysis revealed that right-side AVF and upper arm location are two important clinical risk factors. In addition, two single nucleotide polymorphisms (SNPs), rs275653 (Odds ratio 1.90, p = 0.038) and rs1492099 (Odds ratio 2.29, p = 0.017) of angiotensin II receptor 1 (AGTR1), were associated with increased risk of AVF malfunction. After adjustment for age and other clinical factors, minor allele-containing genotype polymorphisms (AA and CA) of rs1492099 still remained to be a significant risk factor of AVF malfunction (Odds ratio 3.63, p = 0.005). In conclusion, we demonstrated that rs1492099, a SNP of AGTR1 gene, could be a potential genetic risk factor of AVF malfunction in male HD patients. PMID:27240348

New O-C Observations for 150 Algols: Insight to the Origins of Period Shifts

NASA Astrophysics Data System (ADS)

Hoffman, D. I.; Harrison, T. E.; McNamara, B. J.; Vestrand, W. T.

2005-12-01

Many eclipsing binaries of type Algol, RS CVn, and W UMa have observed orbital period shifts. Of these, many show both increasing and decreasing period shifts. Two leading explanations for these shifts are third body effects and magnetic activity changing the oblateness of the secondary, though neither one can explain all of the observed period oscillations. The first-generation Robotic Optical Transient Search Experiment (ROTSE-I) based in Los Alamos, NM, was primarily designed to look for the optical counterparts to gamma-ray bursts as well as searching for other optical transients not detected in gamma-rays. The telescope, consisting of four 200mm camera lenses, can image the entire northern sky twice in a night, which is a very useful tool in monitoring relatively bright eclipsing binaries for period shifts. The public data release from ROTSE-I, the Northern Sky Variability Survey (NSVS), spans one year of data stating in April, 1999. O-C data for 150 eclipsing binaries are presented using the NSVS data. We revisit work by Borkovits and Hegedüs on some third body candidates in several eclipsing binary systems using recent AAVSO and NSVS data. Some unusual light curves of eclipsing binaries produced from NSVS data is presented and discussed.

TRAF3IP2 gene and systemic lupus erythematosus: association with disease susceptibility and pericarditis development.

PubMed

Perricone, Carlo; Ciccacci, Cinzia; Ceccarelli, Fulvia; Di Fusco, Davide; Spinelli, Francesca Romana; Cipriano, Enrica; Novelli, Giuseppe; Valesini, Guido; Conti, Fabrizio; Borgiani, Paola

2013-10-01

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease. Although genetic factors confer susceptibility to the disease, only 15 % of the genetic contribution has been identified. TRAF3IP2 gene, associated with susceptibility to psoriatic arthritis and psoriasis, encodes for Act1, a negative regulator of adaptive immunity and a positive signaling adaptor in IL-17-mediated immune responses. The aim of this study was to assess the role of TRAF3IP2 gene variability in SLE susceptibility and disease phenotype in an Italian population. Two hundred thirty-nine consecutive SLE patients were enrolled. Study protocol included complete physical examination; the clinical and laboratory data were collected. Two hundred seventy-eight age- and ethnicity-matched healthy subjects served as controls. TRAF3IP2 polymorphisms (rs33980500, rs13190932, and rs13193677) were analyzed in both cases and controls. Genotype analysis was performed by allelic discrimination assays. A case-control association study and a genotype-phenotype correlation were performed. The rs33980500 and rs13193677 resulted significantly associated with SLE susceptibility (P = 0.021, odds ratio (OR) = 1.71, and P = 0.046, OR = 1.73, respectively). All three TRAF3IP2 single nucleotide polymorphisms resulted associated with the development of pericarditis; in particular, rs33980500 showed the strongest association (P = 0.002, OR 2.59). This association was further highlighted by binary logistic regression analysis. In conclusion, our data show for the first time the contribution of TRAF3IP2 genetic variability in SLE susceptibility, providing further suggestions that common variation in genes that function in the adaptive and innate arms of the immune system are important in establishing SLE risk. Our study also shows that this gene may affect disease phenotype and, particularly, the occurrence of pericarditis.

Coronal temperatures of unusually active K-dwarf binary systems

NASA Technical Reports Server (NTRS)

Stern, Robert A.

1994-01-01

We report the results of a ROSAT pointed study of 4 BY Dra systems. Good quality pulse-height spectra are available from all four systems. Except for a required interstellar absorption component in HD 319139, the four systems have remarkably similar x-ray spectra; the two systems BD +22deg.669 and BD +23deg.635 look virtually identical in x rays. Analysis of the 4 x-ray spectra reveals that, in all cases, a single-temperature hot plasma (RS or Mewe) spectra is inadequate to fit the data, and two temperatures are required. We present examples of fitted pulse-height spectra and chi squared contours in kT(sub 1)-kT(sub 2) space.

Investigating ChaMPlane X-Ray Sources in the Galactic Bulge with Magellan LDSS2 Spectra

NASA Astrophysics Data System (ADS)

Koenig, Xavier; Grindlay, Jonathan E.; van den Berg, Maureen; Laycock, Silas; Zhao, Ping; Hong, JaeSub; Schlegel, Eric M.

2008-09-01

We have carried out optical and X-ray spectral analyses on a sample of 136 candidate optical counterparts of X-ray sources found in five Galactic bulge fields included in our Chandra Multiwavelength Plane Survey. We use a combination of optical spectral fitting and quantile X-ray analysis to obtain the hydrogen column density toward each object, and a three-dimensional dust model of the Galaxy to estimate the most probable distance in each case. We present the discovery of a population of stellar coronal emission sources, likely consisting of pre-main-sequence, young main-sequence, and main-sequence stars, as well as a component of active binaries of RS CVn or BY Dra type. We identify one candidate quiescent low-mass X-ray binary with a subgiant companion; we note that this object may also be an RS CVn system. We report the discovery of three new X-ray-detected cataclysmic variables (CVs) in the direction of the Galactic center (at distances lesssim2 kpc). This number is in excess of predictions made with a simple CV model based on a local CV space density of lesssim10-5 pc-3, and a scale height ~200 pc. We discuss several possible reasons for this observed excess.

The MAVERIC Survey: A Red Straggler Binary with an Invisible Companion in the Galactic Globular Cluster M10

NASA Astrophysics Data System (ADS)

Shishkovsky, Laura; Strader, Jay; Chomiuk, Laura; Bahramian, Arash; Tremou, Evangelia; Li, Kwan-Lok; Salinas, Ricardo; Tudor, Vlad; Miller-Jones, James C. A.; Maccarone, Thomas J.; Heinke, Craig O.; Sivakoff, Gregory R.

2018-03-01

We present the discovery and characterization of a radio-bright binary in the Galactic globular cluster M10. First identified in deep radio continuum data from the Karl G. Jansky Very Large Array, M10-VLA1 has a flux density of 27 ± 4 μJy at 7.4 GHz and a flat-to-inverted radio spectrum. Chandra imaging shows an X-ray source with L X ≈ 1031 erg s‑1 matching the location of the radio source. This places M10-VLA1 within the scatter of the radio-X-ray luminosity correlation for quiescent stellar-mass black holes, and a black hole X-ray binary is a viable explanation for this system. The radio and X-ray properties of the source disfavor, but do not rule out, identification as an accreting neutron star or white dwarf system. Optical imaging from the Hubble Space Telescope and spectroscopy from the SOAR telescope show that the system has an orbital period of 3.339 days and an unusual “red straggler” component: an evolved star found redward of the M10 red giant branch. These data also show UV/optical variability and double-peaked Hα emission characteristic of an accretion disk. However, SOAR spectroscopic monitoring reveals that the velocity semi-amplitude of the red straggler is low. We conclude that M10-VLA1 is most likely either a quiescent black hole X-ray binary with a rather face-on (i < 4°) orientation or an unusual flaring RS Canum Venaticorum variable-type active binary, and discuss future observations that could distinguish between these possibilities.

The Massive CO White Dwarf in the Symbiotic Recurrent Nova RS Ophiuchi

NASA Astrophysics Data System (ADS)

Mikołajewska, Joanna; Shara, Michael M.

2017-10-01

If accreting white dwarfs (WDs) in binary systems are to produce type Ia supernovae (SNe Ia), they must grow to nearly the Chandrasekhar mass and ignite carbon burning. Proving conclusively that a WD has grown substantially since its birth is a challenging task. Slow accretion of hydrogen inevitably leads to the erosion, rather than the growth of WDs. Rapid hydrogen accretion does lead to growth of a helium layer, due to both decreased degeneracy and the inhibition of mixing of the accreted hydrogen with the underlying WD. However, until recently, simulations of helium-accreting WDs all claimed to show the explosive ejection of a helium envelope once it exceeded ˜ {10}-1 {M}⊙ . Because CO WDs cannot be born with masses in excess of ˜ 1.1 {M}⊙ , any such object in excess of ˜ 1.2 {M}⊙ must have grown substantially. We demonstrate that the WD in the symbiotic nova RS Oph is in the mass range 1.2-1.4 M ⊙. We compare UV spectra of RS Oph with those of novae with ONe WDs and with novae erupting on CO WDs. The RS Oph WD is clearly made of CO, demonstrating that it has grown substantially since birth. It is a prime candidate to eventually produce an SN Ia.

Optical resolution by preferential crystallization of (RS)-2-benzoylamino-2-benzyl-3-hydroxypropanoic acid and its use in synthesizing optically active 2-amino-2-methyl-3-phenylpropanoic acid.

PubMed

Shiraiwa, Tadashi; Suzuki, Masahiro; Sakai, Yoshio; Nagasawa, Hisashi; Takatani, Kazuhiro; Noshi, Daisuke; Yamanashi, Kenji

2002-10-01

To synthesize optically active 2-amino-2-methyl-3-phenylpropanoic acid (1), (RS)-2-benzoylamino-2-benzyl-3-hydroxypropanoic acid [(RS)-2] was first optically resolved using cinchonidine as a resolving agent to yield optically pure (S)- and (R)-2 in yields of about 70%, based on half of the starting amount of (RS)-2. Next, the racemic structure of (RS)-2 was examined based on melting point, solubility, IR spectrum, and binary and ternary phase diagrams, with the aim of optical resolution by preferential crystallization of (RS)-2. Results indicated that the (RS)-2 exists as a conglomerate at room temperature, although it forms a racemic compound at the melting point. The optical resolution by preferential crystallization yielded (S)- and (R)-2 with optical purities of about 90%, which were fully purified by recrystallization. After O-tosylation of (S)- and (R)-2, reduction by zinc powder and sodium iodide gave (R)- and (S)-1, respectively.

Optical and UV spectroscopy of the peculiar RS CVn system RT Lacertae

NASA Technical Reports Server (NTRS)

Huenemoerder, D. P.; Barden, S. C.

1986-01-01

H-alpha and H-beta spectra of the peculiar double-lined RS CVn binary RT Lacertae have been obtained using the IUE, together with a ground-based coude-feed telescope at KPNO. The ground-based spectra show an asymmetry related to the orbital phase in the H-alpha profile. H-beta profiles showed excess emission in one hemisphere and excess absorption in the other, with a broad Gaussian emission component superposed on the excess H-alpha line. A radial velocity curve was derived to estimate the mass ratio and geometry of the system. It is shown that the component of RT Lac fills 80-90 percent of the equilibrium Roche surface. Low-resolution ultraviolet data show that the supposed cooler component is bluer than its companion, suggesting evidence of a scattering shell or a cloud produced by the splash of a gas stream. The phase behavior of the low resolution ultraviolet data support the conclusion that RT Lac is a mass transfer system and that mass transfer is the primary cause of its activity.

Association of Ghrelin Gene Polymorphisms and Serum Ghrelin Levels with the Risk of Hepatitis B Virus-Related Liver Diseases in a Chinese Population.

PubMed

Zhang, Xiaolian; Zhai, Limin; Rong, Chengzhi; Qin, Xue; Li, Shan

2015-01-01

The functions of ghrelin (GHRL) include anti-inflammatory effects, reduction of the fibrogenic response, protection of liver tissue, and regulation of cell proliferation. Genetic variations in the GHRL gene may play an important role in the development of chronic hepatitis B (CHB), liver cirrhosis (LC) and hepatocellular carcinoma (HCC). Therefore, we investigated whether GHRL gene polymorphisms and its serum levels are associated with hepatitis B virus (HBV)-related diseases risk in a Chinese population. 176 patients with CHB, 106 patients with HBV-related LC, 151 patients with HBV-related HCC, and 167 healthy controls were recruited in the study. Genotyping of GHRL rs26311, rs27647, rs696217, and rs34911341 polymorphisms were determined with the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing. The serum GHRL concentrations were determined using enzyme-linked immunosorbent assay (ELISA). Binary logistic regression analyses adjusting for gender and age revealed that a significant increased risk of LC was found in the GHRL rs26311 GC genotype and combined GC+CC genotypes when compared with the GG genotype (GC vs. GG: OR = 1.671, 95% CI = 1.013-2.757, P = 0.044; GC+CC vs. GG: OR = 1.674, 95% CI = 1.040-2.696, P = 0.034). In subgroup analysis by gender, binary logistic regression analyses adjusting for age showed that the GHRL rs26311 C allele and combined GC+CC genotypes were associated with a significantly increased risk to LC in males (C vs. G OR = 1.416, 95% CI = 1.017-1.972, P = 0.040; GC+CC vs. GG: OR = 1.729, 95% CI = 1.019-2.933, P = 0.042). In addition, we found significant decreased serum GHRL levels in LC patients compared with the healthy controls. However, there was no significant association of the GHRL rs26311 polymorphism with serum GHRL levels in LC patients. These observations suggest that the GHRL rs26311 polymorphism is associated with an increased risk to HBV-related LC, especially in men. We also found an inverse association of serum GHRL levels with LC.

Stellar X-Ray Polarimetry

NASA Technical Reports Server (NTRS)

Swank, J.

2011-01-01

Most of the stellar end-state black holes, pulsars, and white dwarfs that are X-ray sources should have polarized X-ray fluxes. The degree will depend on the relative contributions of the unresolved structures. Fluxes from accretion disks and accretion disk corona may be polarized by scattering. Beams and jets may have contributions of polarized emission in strong magnetic fields. The Gravity and Extreme Magnetism Small Explorer (GEMS) will study the effects on polarization of strong gravity of black holes and strong magnetism of neutron stars. Some part of the flux from compact stars accreting from companion stars has been reflected from the companion, its wind, or accretion streams. Polarization of this component is a potential tool for studying the structure of the gas in these binary systems. Polarization due to scattering can also be present in X-ray emission from white dwarf binaries and binary normal stars such as RS CVn stars and colliding wind sources like Eta Car. Normal late type stars may have polarized flux from coronal flares. But X-ray polarization sensitivity is not at the level needed for single early type stars.

Variable Stars Observed in the Galactic Disk by AST3-1 from Dome A, Antarctica

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

Wang, Lingzhi; Ma, Bin; Hu, Yi

AST3-1 is the second-generation wide-field optical photometric telescope dedicated to time-domain astronomy at Dome A, Antarctica. Here, we present the results of an i -band images survey from AST3-1 toward one Galactic disk field. Based on time-series photometry of 92,583 stars, 560 variable stars were detected with i magnitude ≤16.5 mag during eight days of observations; 339 of these are previously unknown variables. We tentatively classify the 560 variables as 285 eclipsing binaries (EW, EB, and EA), 27 pulsating variable stars ( δ Scuti, γ Doradus, δ Cephei variable, and RR Lyrae stars), and 248 other types of variables (unclassifiedmore » periodic, multiperiodic, and aperiodic variable stars). Of the eclipsing binaries, 34 show O’Connell effects. One of the aperiodic variables shows a plateau light curve and another variable shows a secondary maximum after peak brightness. We also detected a complex binary system with an RS CVn-like light-curve morphology; this object is being followed-up spectroscopically using the Gemini South telescope.« less

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

Richards, Mercedes T.; Agafonov, Michail I.; Sharova, Olga I., E-mail: mrichards@astro.psu.edu, E-mail: agfn@nirfi.sci-nnov.ru, E-mail: shol@nirfi.sci-nnov.ru

Time-resolved H{alpha} spectra of magnetically active interacting binaries have been used to create three-dimensional (3D) Doppler tomograms by means of the Radioastronomical Approach. This is the first 3D reconstruction of {beta} Per, with RS Vul for comparison. These 3D tomograms have revealed evidence of the mass transfer process (gas stream, circumprimary emission, localized region, absorption zone), as well as loop prominences and coronal mass ejections (CMEs) in {beta} Per and RS Vul that could not be discovered from two-dimensional tomograms alone. The gas stream in both binaries may have been deflected beyond the central plane by the donor star's magneticmore » field. The stream was more elongated along the predicted trajectory in RS Vul than in {beta} Per, but not as pronounced as in U CrB (stream state). The loop prominence reached maximum V{sub z} velocities of {+-}155 km s{sup -1} in RS Vul compared to {+-}120 km s{sup -1} in {beta} Per, while the CME reached a maximum V{sub z} velocity of +150 km s{sup -1} in RS Vul and +100 km s{sup -1} in {beta} Per. The 3D tomograms show that the gas flows are not symmetric relative to the central plane and are not confined to that plane, a result confirmed by recent 15 GHz VLBI radio images of {beta} Per. Both the 3D H{alpha} tomography and the VLBI radio images support an earlier prediction of the superhump phenomenon in {beta} Per: that the gas between the stars is threaded with a magnetic field even though the hot B8V mass-gaining star is not known to have a magnetic field.« less

Copernicus observations of Ly-alpha and Mg II emission from HR 1099 /V711 Tauri/ and UX Ari

NASA Technical Reports Server (NTRS)

Weiler, E. J.

1978-01-01

Ultraviolet observations of two RS CVn binaries obtained with Copernicus are described. High-resolution (0.05 A) U1 observations indicate that both HR 1099 and UX Ari display broad Ly-alpha emission. The Ly-alpha emission strength from HR 1099 is variable and seems to be correlated with orbital phase, while the UX Ari results indicate no significant variation. Moderate resolution (0.51 A) V2 scans of both systems show variable Mg II h and k emission-line profiles which usually matched the velocity of the more active star in each binary. Additionally, displaced emission components were seen at velocities of up to + or - 250 km/s, indicative of high-velocity gas motions. The radial velocities of these emission features from HR 1099 are marginally correlated with orbital phase. Highly active and variable chromospheric phenomena are found to be the most consistent explanation of these results.

Copernicus observations of interstellar matter in the direction of HR 1099

NASA Technical Reports Server (NTRS)

Anderson, R. C.; Weiler, E. J.

1978-01-01

Results are reported for high-resolution Copernicus U1 and V2 scans of the bright RS CVn spectroscopic binary HR 1099. The observations reveal strong UV emission lines at L-alpha and Mg II h and k from the stars as well as interstellar H I and D I L-alpha absorption lines and interstellar Mg II h and k absorption in the direction of the binary system. Column densities, bulk velocities, and temperatures are derived for the interstellar features. A comparison of the derived number density of interstellar H I with data for the nearby star Epsilon Eri indicates an inhomogeneous distribution of interstellar hydrogen along the line of sight. The range of values obtained for the D/H ratio is shown to be consistent with results of other studies. A depletion factor of at least 5 with respect to the solar abundance is estimated for the interstellar magnesium.

Dissolution stability studies of suspensions of prolonged-release diclofenac microcapsules prepared by the Wurster process: I. Eudragit-based formulation and possible drug-excipient interaction.

PubMed

Adeyeye, M C; Mwangi, E; Katondo, B; Jain, A; Ichikawa, H; Fukumori, Y

2005-06-01

The aim was to evaluate possible interaction in solid and liquid state of the drug with formulation excipients consequent to very fast drug release of diclofenac-Eudragit prolonged release microcapsules. The microcapsules were prepared by drug layering on calcium carbonate cores and coated with Eudragit RS 30D and L30D-55 as previously reported. Suspension of the microcapsules was prepared using microcrystalline cellulose/sodium carboxymethyl cellulose (Avicel CL-611) as medium. In vitro dissolution testing of the suspension was done, and, based on the dissolution results, possible interaction between diclofenac and Eudragit and Avicel in the medium was studied. Powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) analyses were performed using 1:1 binary, 1:1:1 ternary mixtures and a ratio equivalent to that in the formulation. The mixtures were prepared by mixing the dispersions--Eudragit RS 30D or L30D-55 with the drug or other components, followed by drying at 60 degrees C for 48 h. Dry mixing was done using the powder equivalents of the polymers, Eudragit RS PO and L100-55, Avicel and calcium carbonate. In vitro dissolution of the suspended microcapsules showed a very fast release after 48 h (T50 = <1 h) compared to the solid microcapsules (T50 = 6 h). DSC curves of the formulation components or microcapsules did not show the characteristic endothermic peak of diclofenac at 287 degrees C. Powder X-ray diffraction of the binary or ternary mixtures of diclofenac and Eudragit polymers indicated reduction, shift or modification of the crystalline peaks of the drug or excipients at 2theta of 12 degrees and 18 degrees , suggestive of interaction. Some changes in drug peak characteristics at 18 degrees and 23 degrees were observed for Avicel/drug mixture, though not significant. The DSC curves of the binary mixture of diclofenac co-dried with liquid forms of Eudragit (i.e. RS 30D or L30D-55) revealed greater interaction compared to the curves of drug and powdered forms of Eudragit (RS PO or L100-55). This was depicted by greater shift in fusion points of the mixtures relative to the drug. However, comparing the RS and L-type Eudragit, the latter generally showed greater interaction with the drug. Interaction between diclofenac and L-type Eudragit polymers can occur in liquid formulations.

Long-term magnetic activity in close binary systems. I. Patterns of color variations

NASA Astrophysics Data System (ADS)

Messina, S.

2008-03-01

Aims:This is the first of a series of papers in which we present the results of a long-term photometric monitoring project carried out at Catania Astrophysical Observatory aimed at studying magnetic activity in late-type components of close binary systems, its dependence on global stellar parameters, and its evolution on different time scales from days to years. In this first paper, we present the complete observation dataset and new results of an investigation into the origin of brightness and color variations observed in the well-known magnetically active close binary stars: AR Psc, VY Ari, UX Ari, V711 Tau, EI Eri, V1149 Ori, DH Leo, HU Vir, RS CVn, V775 Her, AR Lac, SZ Psc, II Peg and BY Dra Methods: About 38 000 high-precision photoelectric nightly observations in the U, B and V filters are analysed. Correlation and regression analyses of the V magnitude vs. U-B and B-V color variations are carried out and a comparison with model variations for a grid of active region temperature and filling factor values is also performed. Results: We find the existence of two different patterns of color variation. Eight stars in our sample: BY Dra, VY Ari, V775 Her, II Peg, V1149 Ori, HU Vir, EI Eri and DH Leo become redder when they become fainter, as is expected from the presence of active regions consisting of cool spots. The other six stars show the opposite behaviour, i.e. they become bluer when they become fainter. For V711 Tau this behaviour could be explained by the increased relative U- and B-flux contribution by the earlier-type component of the binary system when the cooler component becomes fainter. On the other hand, for AR Psc, UX Ari, RS CVn, SZ Psc and AR Lac the existence of hot photospheric faculae must be invoked. We also found that in single-lined and double-lined binary stars in which the fainter component is inactive or much less active the V magnitude is correlated to B-V and U-B color variations in more than 60% of observation seasons. The correlation is found in less than 40% of observation seasons when the fainter component has a non-negligible level of activity and/or hot faculae are present but they are either spatially or temporally uncorrelated to spots. I dedicate this paper to the memory of the P.I. of this project, Prof. Marcello Rodonò, who suddenly passed away on October 23, 2005. To him my sincere estimation and deepest gratitude. Based on observations collected at INAF-Catania Astrophysical Observatory, Italy.

HE 0017+0055: A probable pulsating CEMP-rs star and long-period binary

NASA Astrophysics Data System (ADS)

Jorissen, A.; Hansen, T.; Van Eck, S.; Andersen, J.; Nordström, B.; Siess, L.; Torres, G.; Masseron, T.; Van Winckel, H.

2016-02-01

Context. A large fraction of the carbon-enhanced, extremely metal-poor halo giants ([Fe/H] < -2.5) are also strongly enriched in neutron-capture elements from the s process (CEMP-s stars). The conventional explanation for the properties of these stars is mass transfer from a nearby binary companion on the asymptotic giant branch (AGB). This scenario leads to a number of testable predictions in terms of the properties of the putative binary system and the resulting abundance pattern. Among the CEMP stars, some stars further exhibit overabundances in r-process elements on top of the s-process enrichment, and are tagged CEMP-rs stars. Although the nucleosynthesis process responsible for this kind of mixed abundance pattern is still under debate, CEMP-rs stars seem to belong to binary systems as do CEMP-s stars. Aims: Our aim is to present and analyse in detail our comprehensive data set of systematic radial-velocity measurements and high-resolution spectroscopy of the CEMP star HE 0017+0055. Methods: Our precise radial-velocity monitoring of HE 0017+0055 over 2940 days (8 yr) with the Nordic Optical Telescope and Mercator telescopes exhibits variability, with a period of 384 d and amplitude of 540 ± 27 m s-1 superimposed on a nearly linear long-term decline of ~1 m s-1 day-1. We used high-resolution HERMES/Mercator and Keck/HIRES spectra to derive elemental abundances with 1D LTE MARCS models. A metallicity of [Fe/H] ~ -2.4 is found, along with s-process overabundances of the order of 2 dex (with the exception of [Y/Fe] ~ + 0.5), and most notably overabundances of r-process elements like Sm, Eu, Dy, and Er in the range 0.9-2.0 dex. With [Ba/Fe] > 1.9 dex and [Eu/Fe] = 2.3 dex, HE 0017+0055 is a CEMP-rs star. We used the derived atmospheric parameters and abundances to infer HE 0017+0055 evolutionary status from a comparison with evolutionary tracks. Results: HE 0017+0055 appears to be a giant star below the tip of the red giant branch. The s-process pollution must therefore originate from mass transfer from a companion formerly on the AGB, which is now a carbon-oxygen white dwarf (WD). If the 384 d velocity variations are attributed to the WD companion, its orbit must be seen almost face-on, with I ~ 2.3°, because the mass function is very small: f(M1,M2) = (6.1 ± 1.1) × 10-6M⊙. Alternatively, the WD orbital motion could be responsible for the long-term velocity variations, with a period of several decades. The 384 d variations should then be attributed either to a low-mass inner companion (perhaps a brown dwarf, depending on the orbital inclination), or to stellar pulsations. The latter possibility is made likely by the fact that similar low-amplitude velocity variations, with periods close to 1 yr, have been reported for other CEMP stars in a companion paper. A definite conclusion about the origin of the 384 d velocity variations should however await the detection of synchronous low-amplitude photometric variations. Based on observations performed with the Mercator telescope and the Nordic Optical Telescope (NOT), operated by the Nordic Optical Telescope Scientific Association at the Roque de los Muchachos Observatory, La Palma, Spain, of the Instituto de Astrofïsica de Canarias.

Genetic Differentiation of North-East Argentina Populations Based on 30 Binary X Chromosome Markers.

PubMed

Di Santo Meztler, Gabriela P; Del Palacio, Santiago; Esteban, María E; Armoa, Isaías; Argüelles, Carina F; Catanesi, Cecilia I

2018-01-01

Alu insertions, INDELs, and SNPs in the X chromosome can be useful not only for revealing relationships among populations but also for identification purposes. We present data of 10 Alu insertions, 5 INDELs, and 15 SNPs of X-chromosome from three Argentinian north-east cities in order to gain insight into the genetic diversity of the X chromosome within this region of the country. Data from 198 unrelated individuals belonging to Posadas, Corrientes, and Eldorado cities were genotyped for Ya5DP62, Yb8DP49, Ya5DP3, Ya5NBC37, Ya5DP77, Ya5NBC491, Ya5DP4, Ya5DP13, Yb8NBC634, and Yb8NBC102 Alu insertions, for MID193, MID1705, MID3754, MID3756 and MID1540 Indels and for rs6639398, rs5986751, rs5964206, rs9781645, rs2209420, rs1299087, rs318173, rs933315, rs1991961, rs4825889, rs1781116, rs1937193, rs1781104, rs149910, and rs652 SNPs. No deviations from Hardy-Weinberg equilibrium were observed for Posadas and Corrientes. However, Eldorado showed significant values, and it was found to have an internal substructuring with two groups of different origin, one showing higher similarity with European countries, and the other with more similarities to Posadas and Corrientes. F st pairwise genetic distances emerged for some markers among the studied populations and also between our data and those from other countries and continents. Of particular interest, Alu insertions demonstrated the most differences, and could be of use in ancestry studies for these populations, while INDELs and SNPs variation were informative for differentiation within the country.

Time-series photometric spot modeling. 2: Fifteen years of photometry of the bright RS CVn binary HR 7275

NASA Technical Reports Server (NTRS)

Strassmeier, K. G.; Hall, D. S.; Henry, G. W.

1994-01-01

We present a time-dependent spot modeling analysis of 15 consecutive years of V-band photometry of the long-period (P(sub orb) = 28.6 days) RS CVn binary HR 7275. This baseline in time is one of the longest, uninterrupted intervals a spotted star has been observed. The spot modeling analysis yields a total of 20 different spots throughout the time span of our observations. The distribution of the observed spot migration rates is consistent with solar-type differential rotation and suggests a lower limit of the differential-rotation coefficient of 0.022 +/-0.004. The observed, maximum lifetime of a single spot (or spot group) is 4.5 years, the minimum lifetime is approximately one year, but an average spot lives for 2.2 years. If we assume that the mechanical shear by differential rotation sets the upper limit to the spot lifetime, the observed maximum lifetime in turn sets an upper limit to the differential-rotation coefficient, namely 0.04 +/- 0.01. This would be differential rotation just 5 to 8 times less than the solar value and one of the strongest among active binaries. We found no conclusive evidence for the existence of a periodic phenomenon that could be attributed to a stellar magnetic cycle.

Association of Ghrelin Gene Polymorphisms and Serum Ghrelin Levels with the Risk of Hepatitis B Virus-Related Liver Diseases in a Chinese Population

PubMed Central

Rong, Chengzhi; Qin, Xue; Li, Shan

2015-01-01

Background The functions of ghrelin (GHRL) include anti-inflammatory effects, reduction of the fibrogenic response, protection of liver tissue, and regulation of cell proliferation. Genetic variations in the GHRL gene may play an important role in the development of chronic hepatitis B (CHB), liver cirrhosis (LC) and hepatocellular carcinoma (HCC). Therefore, we investigated whether GHRL gene polymorphisms and its serum levels are associated with hepatitis B virus (HBV)-related diseases risk in a Chinese population. Methods 176 patients with CHB, 106 patients with HBV-related LC, 151 patients with HBV-related HCC, and 167 healthy controls were recruited in the study. Genotyping of GHRL rs26311, rs27647, rs696217, and rs34911341 polymorphisms were determined with the polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) and DNA sequencing. The serum GHRL concentrations were determined using enzyme-linked immunosorbent assay (ELISA). Results Binary logistic regression analyses adjusting for gender and age revealed that a significant increased risk of LC was found in the GHRL rs26311 GC genotype and combined GC+CC genotypes when compared with the GG genotype (GC vs. GG: OR = 1.671, 95% CI = 1.013–2.757, P = 0.044; GC+CC vs. GG: OR = 1.674, 95% CI = 1.040–2.696, P = 0.034). In subgroup analysis by gender, binary logistic regression analyses adjusting for age showed that the GHRL rs26311 C allele and combined GC+CC genotypes were associated with a significantly increased risk to LC in males (C vs. G OR = 1.416, 95% CI = 1.017–1.972, P = 0.040; GC+CC vs. GG: OR = 1.729, 95% CI = 1.019–2.933, P = 0.042). In addition, we found significant decreased serum GHRL levels in LC patients compared with the healthy controls. However, there was no significant association of the GHRL rs26311 polymorphism with serum GHRL levels in LC patients. Conclusions These observations suggest that the GHRL rs26311 polymorphism is associated with an increased risk to HBV-related LC, especially in men. We also found an inverse association of serum GHRL levels with LC. PMID:26599409

Star-spot distributions and chromospheric activity on the RS CVn type eclipsing binary SV Cam

NASA Astrophysics Data System (ADS)

Şenavcı, H. V.; Bahar, E.; Montes, D.; Zola, S.; Hussain, G. A. J.; Frasca, A.; Işık, E.; Yörükoǧlu, O.

2018-06-01

Using a time series of high-resolution spectra and high-quality multi-colour photometry, we reconstruct surface maps of the primary component of the RS CVn type rapidly rotating eclipsing binary, SV Cam (F9V + K4V). We measure a mass ratio, q, of 0.641(2) using our highest quality spectra and obtain surface brightness maps of the primary component, which exhibit predominantly high-latitude spots located between 60° - 70° latitudes with a mean filling factor of ˜35%. This is also indicated by the R-band light curve inversion, subjected to rigourous numerical tests. The spectral subtraction of the Hα line reveals strong activity of the secondary component. The excess Hα absorption detected near the secondary minimum hints to the presence of cool material partially obscuring the primary star. The flux ratios of Ca II IRT excess emission indicate that the contribution of chromospheric plage regions associated with star-spots is dominant, even during the passage of the filament-like absorption feature.

The behaviour of the excess CA II H and K and Hɛ emissions in chromospherically active binaries.

NASA Astrophysics Data System (ADS)

Montes, D.; Fernandez-Figueroa, M. J.; Cornide, M.; de Castro, E.

1996-08-01

In this work we analyze the behaviour of the excess Ca II H and K and Hɛ emissions in a sample of 73 chromospherically active binary systems (RS CVn and BY Dra classes), of different activity levels and luminosity classes. This sample includes the 53 stars analyzed by Fernandez-Figueroa et al. (1994) and the observations of 28 systems described by Montes et al. (1995c). By using the spectral subtraction technique (subtraction of a synthesized stellar spectrum constructed from reference stars of spectral type and luminosity class similar to those of the binary star components) we obtain the active-chromosphere contribution to the Ca II H and K lines in these 73 systems. We have determined the excess Ca II H and K emission equivalent widths and converted them into surface fluxes. The emissions arising from each component were obtained when it was possible to deblend both contributions. We have found that the components of active binaries are generally stronger emitters than single active stars for a given effective temperature and rotation rate. A slight decline of the excess Ca II H and K emissions towards longer rotation periods, P_rot_, and larger Rossby numbers, R_0_, is found. When we use R_0_ instead of P_rot_ the scatter is reduced and a saturation at R_0_=~0.3 is observed. A good correlation between the excess Ca II K and Hɛ chromospheric emission fluxes has been found. The correlations obtained between the excess Ca II K emission and other activity indicators, (C IV in the transition region, and X-rays in the corona) indicate that the exponents of the power-law relations increase with the formation temperature of the spectral features.

FRZB1 rs2242070 polymorphisms is associated with brick tea type skeletal fluorosis in Kazakhs, but not in Tibetans, China.

PubMed

Yang, Yanmei; Zhao, Qiaoshi; Liu, Yang; Liu, Xiaona; Chu, Yanru; Yan, Huazhu; Fan, Yumei; Huo, Simeng; Wang, Limei; Lou, Qun; Guo, Ning; Sun, Dianjun; Gao, Yanhui

2018-05-21

Skeletal fluorosis is a metabolic bone and joint disease caused by excessive accumulation of fluoride in the bones. Compared with Kazakhs, Tibetans are more likely to develop moderate and severe brick tea type skeletal fluorosis, although they have similar fluoride exposure. Single nucleotide polymorphisms (SNPs) in frizzled-related protein (FRZB) have been associated with osteoarthritis, but their association with the risk of skeletal fluorosis has not been reported. In this paper, we investigated the association of three SNPs (rs7775, rs2242070 and rs9288087) in FRZB1with brick tea type skeletal fluorosis risk in a cross-sectional case-control study conducted in Sinkiang and Qinghai, China. A total of 598 individuals, including 308 Tibetans and 290 Kazakhs, were enrolled in this study, in which cases and controls were 221 and 377, respectively. The skeletal fluorosis was diagnosed according to the Chinese diagnostic criteria of endemic skeletal fluorosis (WS192-2008). The fluoride content in tea water or urine was detected using the fluoride ion electrode. SNPs were assessed using the Sequenom MassARRAY system. Binary logistic regressions found evidence of association with rs2242070 AA genotype in only Kazakh participants [odds ratio (OR) 0.417, 95% CI 0.216-0.807, p = 0.009], but not in Tibetans. When stratified by age, this protective effect of AA genotype in rs2242070 was pronounced in Kazakh participants aged 46-65 (OR 0.321, 95% CI 0.135-0.764, p = 0.010). This protective association with AA genotype in rs2242070 in Kazakhs also appeared to be stronger with tea fluoride intake > 3.5 mg/day (OR 0.396, 95% CI 0.182-0.864, p = 0.020). Our data suggest there might be differential genetic influence on skeletal fluorosis risk in Kazakh and Tibetan participants and that this difference might be modified by tea fluoride intake.

Manufacturing Methods and Technology Project Summary Reports

DTIC Science & Technology

1983-06-01

Proposal will be prepared by Solar Turbines, Inc. for introduction of cast titanium impellers into T62T-40 production. Detroit Diesel Allison will...microprocessor con- trol, RS 232 serial zommunications ports, binary I/O ports, floppy disk mass storage and cor.-rol panal . A component pickup

Evaluation of interatomic potentials for rainbow scattering under axial channeling at KCl(0 0 1) surface by three-dimensional computer simulations based on binary collision approximation

NASA Astrophysics Data System (ADS)

Takeuchi, Wataru

2017-05-01

The rainbow angles corresponding to prominent peaks in the angular distributions of scattered projectiles with small angle, attributed to rainbow scattering (RS), under axial surface channeling conditions are strongly influenced by the interatomic potentials between projectiles and target atoms. The dependence of rainbow angles on normal energy of projectile energy to the target surface, being experimentally obtained by Specht et al. for RS of He, N, Ne and Ar atoms under <1 0 0> and <1 1 0> axial channeling conditions at a KCl(0 0 1) surface with projectile energies of 1-60 keV, was evaluated by the three-dimensional computer simulations using the ACOCT code based on the binary collision approximation with interatomic pair potentials. Good agreement between the ACOCT results using the ZBL pair potential and the individual pair potentials calculated from Hartree-Fock (HF) wave functions and the experimental ones was found for RS of He, N and Ne atoms from the atomic rows along <1 0 0> direction. For <1 1 0> direction, the ACOCT results employing the Moliere pair potential with adjustable screening length of O'Connor-Biersack (OB) formula, the ZBL pair potential and the individual HF pair potentials except for Ar → KCl using the OB pair potential are nearly in agreement with the experimental ones.

Cool stars, stellar systems, and the sun; Proceedings of the 7th Cambridge Workshop, Tucson, AZ, Oct. 9-12, 1991

NASA Technical Reports Server (NTRS)

Giampapa, Mark S. (Editor); Bookbinder, Jay A. (Editor)

1992-01-01

Consideration is given to HST observations of late-type stars, molecular absorption in the UV spectrum of Alpha Ori, EUV emission from late-type stars, Rosat observations of the Pleiades cluster, a deep ROSAT observation of the Hyades cluster, optical spectroscopy detected by EXOSAT, stellar photospheric convection, a structure of the solar X-ray corona, magnetic surface images of the BY Dra Star HD 82558, a Zebra interpretatin of BY Dra stars, optical flares on II Peg, a low-resolution spectroscopic survey of post-T tauri candidates, millimeter and sub-millimeter emission from flare stars, and activity in tidally interacting binaries. Attention is also given to modeling stellar angular momentum evolution, extended 60-micron emission from nearby Mira variables, the PANDORA atmosphere program, the global properties of active regions, oscillations in a stratified atmosphere, lithium abundances in northern RS CVn binaries, a new catalog of cool dwarf stars, the Far UV Spectrograph Explorer, and development of reflecting coronagraphs.

Multilocus family-based association analysis of seven candidate polymorphisms with essential hypertension in an african-derived semi-isolated brazilian population.

PubMed

Kimura, L; Angeli, C B; Auricchio, M T B M; Fernandes, G R; Pereira, A C; Vicente, J P; Pereira, T V; Mingroni-Netto, R C

2012-01-01

Background. It has been widely suggested that analyses considering multilocus effects would be crucial to characterize the relationship between gene variability and essential hypertension (EH). Objective. To test for the presence of multilocus effects between/among seven polymorphisms (six genes) on blood pressure-related traits in African-derived semi-isolated Brazilian populations (quilombos). Methods. Analyses were carried out using a family-based design in a sample of 652 participants (97 families). Seven variants were investigated: ACE (rs1799752), AGT (rs669), ADD2 (rs3755351), NOS3 (rs1799983), GNB3 (rs5441 and rs5443), and GRK4 (rs1801058). Sensitivity analyses were further performed under a case-control design with unrelated participants only. Results. None of the investigated variants were associated individually with both systolic and diastolic BP levels (SBP and DBP, respectively) or EH (as a binary outcome). Multifactor dimensionality reduction-based techniques revealed a marginal association of the combined effect of both GNB3 variants on DBP levels in a family-based design (P = 0.040), whereas a putative NOS3-GRK4 interaction also in relation to DBP levels was observed in the case-control design only (P = 0.004). Conclusion. Our results provide limited support for the hypothesis of multilocus effects between/among the studied variants on blood pressure in quilombos. Further larger studies are needed to validate our findings.

HPLC enantioseparation of racemic bupropion, baclofen and etodolac: modification of conventional ligand exchange approach by pre-column formation of chiral ligand exchange complexes.

PubMed

Singh, Manisha; Bhushan, Ravi

2016-11-01

Separation of racemic mixture of (RS)-bupropion, (RS)-baclofen and (RS)-etodolac, commonly marketed racemic drugs, has been achieved by modifying the conventional ligand exchange approach. The Cu(II) complexes were first prepared with a few l-amino acids, namely, l-proline, l-histidine, l-phenylalanine and l-tryptophan, and to these was introduced a mixture of the enantiomer pair of (RS)-bupropion, or (RS)-baclofen or (RS)-etodolac. As a result, formation of a pair of diastereomeric complexes occurred by 'chiral ligand exchange' via the competition between the chelating l-amino acid and each of the two enantiomers from a given pair. The diastereomeric mixture formed in the pre-column process was loaded onto HPLC column. Thus, both the phases during chromatographic separation process were achiral (i.e. neither the stationary phase had any chiral structural feature of its own nor did the mobile phase have any chiral additive). Separation of diastereomers was successful using a C 18 column and a binary mixture of MeCN and TEAP buffer of pH 4.0 (60:40, v/v) as mobile phase at a flow rate of 1 mL/min and UV detection at 230 nm for (RS)-Bup, 220 nm for (RS)-Bac and 223 nm for (RS)-Etd. Baseline separation of the two enantiomers was obtained with a resolution of 6.63 in <15 min. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

V850 Cyg: An eclipsing binary with a giant γ Dor pulsator

NASA Astrophysics Data System (ADS)

Çakırlı, Ö.; Ibanoglu, C.; Sipahi, E.; Akan, M. C.

2017-04-01

We present new spectroscopic observations of the double-lined eclipsing binary V850 Cyg. The long-cadence photometric observations obtained by Kepler were analysed and combined with the analysis of radial velocities for deriving the absolute parameters of the components. Masses and radii were determined as Mp=1.601 ± 0.076 M⊙ and Rp=4.239 ± 0.076 R⊙, Ms=0.851 ± 0.053 M⊙ and Rs=5.054 ± 0.087 R⊙ for the components of V850 Cyg. We estimate an interstellar reddening of 0.28 ± 0.12 mag and a distance of 1040 ± 160 pc for the system. The measured rotational velocity of the secondary appears to lower than that of synchronize rotation. However its spectral lines are too weak to be measured the rotational velocity with reasonable accuracy. We have extracted the synthetic light curve from the observations and excluded the data within the eclipses for the frequency analysis. We obtained at least nine frequencies in the γ Dor regime. It seems that the primary component oscillates with a dominant period of about 1.152549 ± 0.000009 days. We also compare pulsational properties of the primary star of V850 Cyg with the γ Dor type pulsating components in other binaries.

Interactions of six SNPs in APOA1 gene and types of obesity on low HDL-C disease in Xinjiang pastoral area of China.

PubMed

Wang, Xinping; He, Jia; Guo, Heng; Mu, Lati; Hu, Yunhua; Ma, Jiaolong; Yan, Yizhong; Ma, Rulin; Li, Shugang; Ding, Yusong; Zhang, Mei; Niu, Qiang; Liu, Jiaming; Zhang, Jingyu; Guo, Shuxia

2017-10-02

This study aims to investigate association between six single nucleotide polymorphisms(SNPs) in APOA1 gene and types of obesity with the risk of low level HDL-C in the pastoral area of northwest China. A total of 1267 individuals including 424 patients with low HDL-C disease and 843 health subjects were analyzed based on matched for age, sex. SNPShot technique was used to detect the genotypes of rs670, rs5069, rs5072, rs7116797, rs2070665 and rs1799837 in APOA1 gene. The relationship between above six SNPs and types of obesity with low HDL-C disease was analyzed by binary logistic regression. Carriers with rs670 G allele were more likely to get low HDL-C disease (OR = 1.46, OR95%CI: 1.118-1.915; P = 0.005); The genotypic and allelic frequencies of rs5069, rs5072, rs7116797, rs2070665, rs1799837 revealed no significant differences between cases and controls (P < 0.05); with reference to normal weight, Waist circumference (WC), Waist-to-hip ratio (WHR) individuals, respectively, general obesity measured by BMI had 2.686 times (OR95%CI: 1.695-4.256; P < 0.01), abdominal obesity measured by WC had 1.925 times (OR95%CI: 1.273-2.910; P = 0.002) and abdominal obesity measured by WHR had 1.640 times (OR95%CI: 1.114-2.416; P = 0.012) risk to get low HDL-C disease; APOA1 rs670 interacted with obesity (no matter general obesity or abdominal obesity) on low HDL-C disease. APOA1 gene may be associated with low HDL-C disease in the pastoral area of northwest China; obesity was the risk factor for low HDL-C disease; the low HDL-C disease is influenced by APOA1, obesity, and their interactions.

Excess Hα emission in chromospherically active binaries.

NASA Astrophysics Data System (ADS)

Montes, D.; Fernandez-Figueroa, M. J.; de Castro, E.; Cornide, M.

1995-02-01

We study the behaviour of the excess Hα emission in a sample of 51 chromospherically active binary systems (RS CVn and BY Dra classes), of different activity levels. This sample include the 27 stars analysed by Fernandez-Figueroa et al. (1994) and the new observations of 24 systems described by Montes et al. (1994b). By using the spectral subtraction technique (subtraction of a synthesized stellar spectrum constructed from reference stars of similar spectral type and luminosity class) we obtain the active-chromosphere contribution to the Hα line in these 51 systems. We have determined the excess Hα emission equivalent widths and converted it to surface fluxes. The Hα emissions arising from each component star were obtained when it was possible to deblend both contributions. The comparison of the excess Hα emission, obtained with the spectral subtraction technique, with other Hα activity indices allows us to conclude that this is the preferable activity indicator for binaries. The behaviour of the excess Hα emission as a function of the rotation has been analyzed. A slight decline toward longer rotational periods, P_rot_, and larger Rossby numbers, R_0_, is present in agreement with previous results using others activity indicators. We have compared the derived excess Hα emission fluxes with those obtained in the Ca II K and Hɛ lines finding that a good correlation exits between these three chromospheric activity indicators. The Hα losses seem to be more important than Ca II K losses for cooler stars, in fact all the system with Hα emission above the continuum are cooler than 5000K. Correlations with other activity indicators, (C IV in the transition region, and X-rays in the corona) indicate that the exponents of the power-law relations increase with the formation temperature of the spectral features.

Orbital Elements and Stellar Parameters of the Active Binary UX Arietis

NASA Astrophysics Data System (ADS)

Hummel, C. A.; Monnier, J. D.; Roettenbacher, R. M.; Torres, G.; Henry, G. W.; Korhonen, H.; Beasley, A.; Schaefer, G. H.; Turner, N. H.; Ten Brummelaar, T.; Farrington, C. D.; Sturmann, J.; Sturmann, L.; Baron, F.; Kraus, S.

2017-08-01

Stellar activity observed as large surface spots, radio flares, or emission lines is often found in binary systems. UX Arietis exhibits these signs of activity, originating on the K0 subgiant primary component. Our aim is to resolve the binary, measure the orbital motion, and provide accurate stellar parameters such as masses and luminosities to aid in the interpretation of the observed phenomena. Using the CHARA six-telescope optical long-baseline array on Mount Wilson, California, we obtained amplitudes and phases of the interferometric visibility on baselines up to 330 m in length, resolving the two components of the binary. We reanalyzed archival Center for Astrophysics spectra to disentangle the binary component spectra and the spectrum of the third component, which was resolved by speckle interferometry. We also obtained new spectra with the Nordic Optical Telescope, and we present new photometric data that we use to model stellar surface spot locations. Both interferometric visibilities and spectroscopic radial velocities are modeled with a spotted primary stellar surface using the Wilson-Devinney code. We fit the orbital elements to the apparent orbit and radial velocity data to derive the distance (52.1 ± 0.8 pc) and stellar masses ({M}{{P}}=1.30+/- 0.06 {M}⊙ , {M}{{S}}=1.14+/- 0.06 {M}⊙ ). The radius of the primary can be determined to be {R}{{P}}=5.6+/- 0.1 {R}⊙ and that of the secondary to be {R}{{S}}=1.6+/- 0.2 {R}⊙ . The equivalent spot coverage of the primary component was found to be 62% with an effective temperature 20% below that of the unspotted surface.

Association of Computed Tomography Ischemic Lesion Location With Functional Outcome in Acute Large Vessel Occlusion Ischemic Stroke.

PubMed

Ernst, Marielle; Boers, Anna M M; Aigner, Annette; Berkhemer, Olvert A; Yoo, Albert J; Roos, Yvo B; Dippel, Diederik W J; van der Lugt, Aad; van Oostenbrugge, Robert J; van Zwam, Wim H; Fiehler, Jens; Marquering, Henk A; Majoie, Charles B L M

2017-09-01

Ischemic lesion volume (ILV) assessed by follow-up noncontrast computed tomography correlates only moderately with clinical end points, such as the modified Rankin Scale (mRS). We hypothesized that the association between follow-up noncontrast computed tomography ILV and outcome as assessed with mRS 3 months after stroke is strengthened when taking the mRS relevance of the infarct location into account. An anatomic atlas with 66 areas was registered to the follow-up noncontrast computed tomographic images of 254 patients from the MR CLEAN trial (Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands). The anatomic brain areas were divided into brain areas of high, moderate, and low mRS relevance as reported in the literature. Based on this distinction, the ILV in brain areas of high, moderate, and low mRS relevance was assessed for each patient. Binary and ordinal logistic regression analyses with and without adjustment for known confounders were performed to assess the association between the ILVs of different mRS relevance and outcome. The odds for a worse outcome (higher mRS) were markedly higher given an increase of ILV in brain areas of high mRS relevance (odds ratio, 1.42; 95% confidence interval, 1.31-1.55 per 10 mL) compared with an increase in total ILV (odds ratios, 1.16; 95% confidence interval, 1.12-1.19 per 10 mL). Regression models using ILV in brain areas of high mRS relevance instead of total ILV showed a higher quality. The association between follow-up noncontrast computed tomography ILV and outcome as assessed with mRS 3 months after stroke is strengthened by accounting for the mRS relevance of the affected brain areas. Future prediction models should account for the ILV in brain areas of high mRS relevance. © 2017 American Heart Association, Inc.

Optical flip-flops in a polarization-encoded optical shadow-casting scheme.

PubMed

Rizvi, R A; Zubairy, M S

1994-06-10

We propose a novel scheme that optically implements various types of binary sequential logic elements. This is based on a polarization-encoded optical shadow-casting system. The proposed system architecture is capable of implementing synchronous as well as asynchronous sequential circuits owing to the inherent structural flexibility of optical shadow casting. By employing the proposed system, we present the design and implementation schemes of a J-K flip-flop and clocked R-S and D latches. The main feature of these flip-flops is that the propagation of the signal from the input plane to the output (i.e., processing) and from the output plane to the source plane (i.e., feedback) is all optical. Consequently the efficiency of these elements in terms of speed is increased. The only electronic part in the system is the detection of the outputs and the switching of the source plane.

Cool Spot and Flare Activities of a RS CVn Binary KIC 7885570

NASA Astrophysics Data System (ADS)

Kunt, M.; Dal, H. A.

2017-12-01

We present here the results of our studies on the physical nature and chromospheric activity of a RS CVn binary KIC 7885570 based on the Kepler Mission data. Assuming the primary component temperature, 6530 K, the temperature of the secondary component was found to be 5732±4 K. The mass ratio of the components (q) was found to be 0.43±0.01, while the inclination (i) of the system - 80.6°±0.1°. Additionally, the data were separated into 35 subsets to model the sinusoidal variation due to the rotational modulation, using the SpotModel program, as the light curve analysis indicated the chromospherically active secondary component. It was found that there are generally two spotted areas, whose radii, longitudes and latitudes are rapidly changing, located around the latitudes of +50° and +90° on the active component. Moreover, 113 flares were detected and their parameters were computed from the available data. The One Phase Exponential Association function model was derived from the parameters of these flares. Using the regression calculations, the Plateau value was found to be 1.9815±0.1177, while the half-life value was computed as 3977.2 s. In addition, the flare frequency (N1) - the flare number per hour, was estimated to be 0.00362 h-1, while flare frequency (N2) - the flare-equivalent duration emitted per hour, was computed as 0.00001. Finally, the times of eclipses were computed for 278 minima of the light curves, whose analysis indicated that the chromosphere activity nature of the system causes some effects on these minima times. Comparing the chromospheric activity patterns with the analogues of the secondary component, it is seen that the magnetic activity level is remarkably low. However, it is still at the expected level according to the B-V color index of 0.643 mag for the secondary component.

Green binary and phase shifting mask

NASA Astrophysics Data System (ADS)

Shy, S. L.; Hong, Chao-Sin; Wu, Cheng-San; Chen, S. J.; Wu, Hung-Yu; Ting, Yung-Chiang

2009-12-01

SixNy/Ni thin film green mask blanks were developed , and are now going to be used to replace general chromium film used for binary mask as well as to replace molydium silicide embedded material for AttPSM for I-line (365 nm), KrF (248 nm), ArF (193 nm) and Contact/Proximity lithography. A bilayer structure of a 1 nm thick opaque, conductive nickel layer and a SixNy layer is proposed for binary and phase-shifting mask. With the good controlling of plasma CVD of SixNy under silane (50 sccm), ammonia (5 sccm) and nitrogen (100 sccm), the pressure is 250 mTorr. and RF frequency 13.56 MHz and power 50 W. SixNy has enough deposition latitude to meet the requirements as an embedded layer for required phase shift 180 degree, and the T% in 193, 248 and 365 nm can be adjusted between 2% to 20% for binary and phase shifting mask usage. Ni can be deposited by E-gun, its sheet resistance Rs is less than 1.435 kΩ/square. Jeol e-beam system and I-line stepper are used to evaluate these thin film green mask blanks, feature size less than 200 nm half pitch pattern and 0.558 μm pitch contact hole can be printed. Transmission spectrums of various thickness of SixNy film are inspected by using UV spectrometer and FTIR. Optical constants of the SixNy film are measured by n & k meter and surface roughness is inspected by using Atomic Force Microscope (AFM).

Fesbnd X (X = B, N) binary compounds: First-principles calculations of electronic structures, theoretic hardness and magnetic properties

NASA Astrophysics Data System (ADS)

Hui, Liangliang; Xie, Zhongjing; Li, Chunmei; Chen, Zhi-Qian

2018-04-01

The first-principles calculations are implemented to investigate the electronic structures, theoretic hardness and magnetic properties of iron borides and nitrides with four different crystal systems containing hexagonal (FeB2, ε-Fe3N), tetragonal (Fe2B, α″-Fe16N2), orthorhombic (α-FeB, θ-Fe3B, ζ-Fe2N), and cubic (zb-FeN, rs-FeN, γ‧-Fe4N, γ-Fe23B6) phase. The calculated lattice parameters using RPBE meet well with the experimental results. The cohesive energy and formation enthalpy values indicate the Fesbnd X (X = B, N) binary compounds are thermodynamically stable. Meanwhile, the h-FeB2 is most difficult phase for experimental synthesis among these interstitial compounds. Moreover, magnetic properties are discussed and show that the mean magnetic moments of o-Fe3B and c-Fe23B6 with the values of 2.227 μB and 2.256 μB per iron atom are approaching to that of pure iron (2.32 μB) while the c-Fe4N and t-Fe16N2 with the values of 2.51 and 2.48 μB are beyond that of pure α-Fe. The c-FeN phase shows nonmagnetic in zb-style while rs-type shows antiferromagnetic with a value of 2.52 μB. Furthermore, the average bonding length and Mulliken population combined with electronic structures are also analysed in this paper which provide that strong Fesbnd X and Xsbnd X covalent bonds are responsible for high hardness. Finally, the theoretic hardness of Xsbnd X, Fesbnd X and Fesbnd Fe bonds is predicted by semi empirical hardness theory.

Rhinoscleroma: a detailed histopathological diagnostic insight

PubMed Central

Ahmed, Ahmed RH; El-badawy, Zeinab H; Mohamed, Ibrahim R; Abdelhameed, Waleed AM

2015-01-01

Rhinoscleroma (RS) is a chronic specific disease of nose and upper respiratory passages caused by Klebsiella rhinoscleromatis bacilli. It is endemic in Egypt and in sporadic areas worldwide. Diagnosis of RS depends on identification of the pathognomonic Mickulicz cells (MCs) which is most prominent during granulomatous phase but spares or absent during catarrhal or sclerotic phases of the disease. This study aimed to identify the potential diagnostic features of nasal RS when MCs are absent. Nasal biopsies from 125 patients complaining of chronic nasal symptoms were retrieved for this study; including 72 chronic non specific inflammatory lesions and 53 RS diagnosed by PAS and Geimsa stains. The detailed histological differences among the two groups were measured statistically. RS was frequently a bilateral disease (P < 0.05) of young age (P < 0.001) with a female predominance (P < 0.05) and usually associated with nasal crustations (P < 0.001). Five strong histological indicators of RS were specified by univariate binary logistic regression analyses including squamous metaplasia (OR 27.2, P < 0.0001), dominance of plasma cells (OR 12.75, P < 0.0001), Russell bodies (OR 8.83, P < 0.0001), neutrophiles (OR 3.7, P < 0.001) and absence of oesinophiles (OR 12.0, P < 0.0001). According to Multivariate analysis, the diagnostic features of RS in absence of MCs can be classified into major criteria including dominance of plasma cells infiltration and absence of oesinophiles and minor criteria including young age, female gender, bilateral nasal involvement, nasal crustation, squamous metaplasia, Russell bodies, and neutrophiles. The diagnostic model using the two major criteria confirmed or excluded RS in 84.3% of the investigated cases. PMID:26339415

Fat mass and obesity-associated gene rs11642015 polymorphism is significantly associated with prediabetes and type 2 diabetes subsequent to adjustment for body mass index.

PubMed

Han, Liyuan; Tang, Linlin; Wang, Changyi; Chen, Zhongwei; Zhang, Tao; Chen, Sihan; Liu, Shengyuan; Peng, Xiaolin; Mai, Yifeng; Duan, Shiwei

2014-09-01

The association of the fat mass and obesity-associated gene ( FTO ) rs11642015 polymorphism with prediabetes, type 2 diabetes and obesity in certain populations has not been previously reported. A population-based study was conducted that included 490 type 2 diabetic, 471 prediabetic and 575 normal subjects. The main outcomes of the study were prediabetes, type 2 diabetes and obesity. Binary logistic regression was performed to estimate the association of FTO rs11642015 with the risk of prediabetes, type 2 diabetes and obesity following adjustment for the corresponding confounders. A meta-analysis was also conducted to evaluate the association between FTO rs11642015 and obesity. FTO rs11642015 was significantly associated with prediabetes in the whole sample under the additive model [odds ratio (OR), 1.50; 95% confidence interval (CI), 1.17-1.93; P=0.002], particularly in females. The polymorphism remained consistently significant following adjustment for age and body mass index (BMI), showing an increased prediabetes risk with an additive effect (OR, 1.55; 95% CI, 1.19-2.01; P=0.001). In addition, a significant association was found for rs11642015 with prediabetes and type 2 diabetes under the dominant model. However, under the stringent Bonferroni's correction there was no evidence of positive associations for FTO rs11642015 with obesity in the whole sample, females or males. Findings of the meta-analysis showed that FTO rs11642015 was not predisposed to obesity. In conclusion, the T allele of FTO rs11642015 is positively associated with an increased risk of prediabetes, even after adjustment for age and BMI, particularly in females. Subjects carrying the CT + TT genotype are predisposed to prediabetes and type 2 diabetes. Therefore, results of the population-based study and follow-up meta-analysis suggested that FTO rs11642015 is not significantly associated with susceptibility to obesity.

Association Study with 77 SNPs Confirms the Robust Role for the rs10830963/G of MTNR1B Variant and Identifies Two Novel Associations in Gestational Diabetes Mellitus Development.

PubMed

Rosta, Klara; Al-Aissa, Zahra; Hadarits, Orsolya; Harreiter, Jürgen; Nádasdi, Ákos; Kelemen, Fanni; Bancher-Todesca, Dagmar; Komlósi, Zsolt; Németh, László; Rigó, János; Sziller, István; Somogyi, Anikó; Kautzky-Willer, Alexandra; Firneisz, Gábor

2017-01-01

Genetic variation in human maternal DNA contributes to the susceptibility for development of gestational diabetes mellitus (GDM). We assessed 77 maternal single nucleotide gene polymorphisms (SNPs) for associations with GDM or plasma glucose levels at OGTT in pregnancy. 960 pregnant women (after dropouts 820: case/control: m99'WHO: 303/517, IADPSG: 287/533) were enrolled in two countries into this case-control study. After genomic DNA isolation the 820 samples were collected in a GDM biobank and assessed using KASP (LGC Genomics) genotyping assay. Logistic regression risk models were used to calculate ORs according to IADPSG/m'99WHO criteria based on standard OGTT values. The most important risk alleles associated with GDM were rs10830963/G of MTNR1B (OR = 1.84/1.64 [IADPSG/m'99WHO], p = 0.0007/0.006), rs7754840/C (OR = 1.51/NS, p = 0.016) of CDKAL1 and rs1799884/T (OR = 1.4/1.56, p = 0.04/0.006) of GCK. The rs13266634/T (SLC30A8, OR = 0.74/0.71, p = 0.05/0.02) and rs7578326/G (LOC646736/IRS1, OR = 0.62/0.60, p = 0.001/0.006) variants were associated with lower risk to develop GDM. Carrying a minor allele of rs10830963 (MTNR1B); rs7903146 (TCF7L2); rs1799884 (GCK) SNPs were associated with increased plasma glucose levels at routine OGTT. We confirmed the robust association of MTNR1B rs10830963/G variant with GDM binary and glycemic traits in this Caucasian case-control study. As novel associations we report the minor, G allele of the rs7578326 SNP in the LOC646736/IRS1 region as a significant and the rs13266634/T SNP (SLC30A8) as a suggestive protective variant against GDM development. Genetic susceptibility appears to be more preponderant in individuals who meet both the modified 99'WHO and the IADPSG GDM diagnostic criteria.

Utility-Weighted Modified Rankin Scale as Primary Outcome in Stroke Trials

PubMed Central

Voormolen, Daphne C.; Venema, Esmee; Roozenbeek, Bob; Polinder, Suzanne; Haagsma, Juanita A.; Nieboer, Daan; Chalos, Vicky; Yoo, Albert J.; Schreuders, Jennifer; van der Lugt, Aad; Majoie, Charles B.L.M.; Roos, Yvo B.W.E.M.; van Zwam, Wim H.; van Oostenbrugge, Robert J.; Steyerberg, Ewout W.; Dippel, Diederik W.J.; Lingsma, Hester F.

2018-01-01

Background and Purpose— The utility-weighted modified Rankin Scale (UW-mRS) has been proposed as a new patient-centered primary outcome in stroke trials. We aimed to describe utility weights for the mRS health states and to evaluate the statistical efficiency of the UW-mRS to detect treatment effects in stroke intervention trials. Methods— We used data of the 500 patients enrolled in the MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands). Utility values were elicited from the EuroQol Group 5-Dimension Self-Report Questionnaire assessed at 90 days after inclusion, simultaneously with the mRS. Utility weights were determined by averaging the utilities of all patients within each mRS category. We performed simulations to evaluate statistical efficiency. The simulated treatment effect was an odds ratio of 1.65 in favor of the treatment arm, similar for all mRS cutoffs. This treatment effect was analyzed using 3 approaches: linear regression with the UW-mRS as outcome, binary logistic regression with a dichotomized mRS (0–1/2–6, 0–2/3–6, and 0–4/5–6), and proportional odds logistic regression with the ordinal mRS. The statistical power of the 3 approaches was expressed as the proportion of 10 000 simulations that resulted in a statistically significant treatment effect (P≤0.05). Results— The mean utility values (SD) for mRS categories 0 to 6 were: 0.95 (0.08), 0.93 (0.13), 0.83 (0.21), 0.62 (0.27), 0.42 (0.28), 0.11 (0.28), and 0 (0), respectively, but varied substantially between individual patients within each category. The UW-mRS approach was more efficient than the dichotomous approach (power 85% versus 71%) but less efficient than the ordinal approach (power 85% versus 87%). Conclusions— The UW-mRS as primary outcome does not capture individual variation in utility values and may reduce the statistical power of a randomized trial. PMID:29535271

Contribution of common non-synonymous variants in PCSK1 to body mass index variation and risk of obesity: a systematic review and meta-analysis with evidence from up to 331 175 individuals.

PubMed

Nead, Kevin T; Li, Aihua; Wehner, Mackenzie R; Neupane, Binod; Gustafsson, Stefan; Butterworth, Adam; Engert, James C; Davis, A Darlene; Hegele, Robert A; Miller, Ruby; den Hoed, Marcel; Khaw, Kay-Tee; Kilpeläinen, Tuomas O; Wareham, Nick; Edwards, Todd L; Hallmans, Göran; Varga, Tibor V; Kardia, Sharon L R; Smith, Jennifer A; Zhao, Wei; Faul, Jessica D; Weir, David; Mi, Jie; Xi, Bo; Quinteros, Samuel Canizales; Cooper, Cyrus; Sayer, Avan Aihie; Jameson, Karen; Grøntved, Anders; Fornage, Myriam; Sidney, Stephen; Hanis, Craig L; Highland, Heather M; Häring, Hans-Ulrich; Heni, Martin; Lasky-Su, Jessica; Weiss, Scott T; Gerhard, Glenn S; Still, Christopher; Melka, Melkaey M; Pausova, Zdenka; Paus, Tomáš; Grant, Struan F A; Hakonarson, Hakon; Price, R Arlen; Wang, Kai; Scherag, Andre; Hebebrand, Johannes; Hinney, Anke; Franks, Paul W; Frayling, Timothy M; McCarthy, Mark I; Hirschhorn, Joel N; Loos, Ruth J; Ingelsson, Erik; Gerstein, Hertzel C; Yusuf, Salim; Beyene, Joseph; Anand, Sonia S; Meyre, David

2015-06-15

Polymorphisms rs6232 and rs6234/rs6235 in PCSK1 have been associated with extreme obesity [e.g. body mass index (BMI) ≥ 40 kg/m(2)], but their contribution to common obesity (BMI ≥ 30 kg/m(2)) and BMI variation in a multi-ethnic context is unclear. To fill this gap, we collected phenotypic and genetic data in up to 331 175 individuals from diverse ethnic groups. This process involved a systematic review of the literature in PubMed, Web of Science, Embase and the NIH GWAS catalog complemented by data extraction from pre-existing GWAS or custom-arrays in consortia and single studies. We employed recently developed global meta-analytic random-effects methods to calculate summary odds ratios (OR) and 95% confidence intervals (CIs) or beta estimates and standard errors (SE) for the obesity status and BMI analyses, respectively. Significant associations were found with binary obesity status for rs6232 (OR = 1.15, 95% CI 1.06-1.24, P = 6.08 × 10(-6)) and rs6234/rs6235 (OR = 1.07, 95% CI 1.04-1.10, P = 3.00 × 10(-7)). Similarly, significant associations were found with continuous BMI for rs6232 (β = 0.03, 95% CI 0.00-0.07; P = 0.047) and rs6234/rs6235 (β = 0.02, 95% CI 0.00-0.03; P = 5.57 × 10(-4)). Ethnicity, age and study ascertainment significantly modulated the association of PCSK1 polymorphisms with obesity. In summary, we demonstrate evidence that common gene variation in PCSK1 contributes to BMI variation and susceptibility to common obesity in the largest known meta-analysis published to date in genetic epidemiology. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Contribution of common non-synonymous variants in PCSK1 to body mass index variation and risk of obesity: a systematic review and meta-analysis with evidence from up to 331 175 individuals

PubMed Central

Nead, Kevin T.; Li, Aihua; Wehner, Mackenzie R.; Neupane, Binod; Gustafsson, Stefan; Butterworth, Adam; Engert, James C.; Davis, A. Darlene; Hegele, Robert A.; Miller, Ruby; den Hoed, Marcel; Khaw, Kay-Tee; Kilpeläinen, Tuomas O.; Wareham, Nick; Edwards, Todd L.; Hallmans, Göran; Varga, Tibor V.; Kardia, Sharon L. R.; Smith, Jennifer A.; Zhao, Wei; Faul, Jessica D.; Weir, David; Mi, Jie; Xi, Bo; Quinteros, Samuel Canizales; Cooper, Cyrus; Sayer, Avan Aihie; Jameson, Karen; Grøntved, Anders; Fornage, Myriam; Sidney, Stephen; Hanis, Craig L.; Highland, Heather M.; Häring, Hans-Ulrich; Heni, Martin; Lasky-Su, Jessica; Weiss, Scott T.; Gerhard, Glenn S.; Still, Christopher; Melka, Melkaey M.; Pausova, Zdenka; Paus, Tomáš; Grant, Struan F. A.; Hakonarson, Hakon; Price, R. Arlen; Wang, Kai; Scherag, Andre; Hebebrand, Johannes; Hinney, Anke; Franks, Paul W.; Frayling, Timothy M.; McCarthy, Mark I.; Hirschhorn, Joel N.; Loos, Ruth J.; Ingelsson, Erik; Gerstein, Hertzel C.; Yusuf, Salim; Beyene, Joseph; Anand, Sonia S.; Meyre, David

2015-01-01

Polymorphisms rs6232 and rs6234/rs6235 in PCSK1 have been associated with extreme obesity [e.g. body mass index (BMI) ≥ 40 kg/m2], but their contribution to common obesity (BMI ≥ 30 kg/m2) and BMI variation in a multi-ethnic context is unclear. To fill this gap, we collected phenotypic and genetic data in up to 331 175 individuals from diverse ethnic groups. This process involved a systematic review of the literature in PubMed, Web of Science, Embase and the NIH GWAS catalog complemented by data extraction from pre-existing GWAS or custom-arrays in consortia and single studies. We employed recently developed global meta-analytic random-effects methods to calculate summary odds ratios (OR) and 95% confidence intervals (CIs) or beta estimates and standard errors (SE) for the obesity status and BMI analyses, respectively. Significant associations were found with binary obesity status for rs6232 (OR = 1.15, 95% CI 1.06–1.24, P = 6.08 × 10−6) and rs6234/rs6235 (OR = 1.07, 95% CI 1.04–1.10, P = 3.00 × 10−7). Similarly, significant associations were found with continuous BMI for rs6232 (β = 0.03, 95% CI 0.00–0.07; P = 0.047) and rs6234/rs6235 (β = 0.02, 95% CI 0.00–0.03; P = 5.57 × 10−4). Ethnicity, age and study ascertainment significantly modulated the association of PCSK1 polymorphisms with obesity. In summary, we demonstrate evidence that common gene variation in PCSK1 contributes to BMI variation and susceptibility to common obesity in the largest known meta-analysis published to date in genetic epidemiology. PMID:25784503

Optical and UV spectroscopy of the peculiar RS CVn system, RT Lacertae

NASA Technical Reports Server (NTRS)

Huenemoerder, D. P.; Barden, S. C.

1985-01-01

Spectra in the H-alpha and H-beta regions of the peculiar double-lined RS CVn binary, RT Lacertae, were obtained in the fall of 1984. Limited International Ultraviolet Explorer (IUE) long wavelength low and high resolution spectra were obtained concurrently. The ground based spectra have shown an asymmetry with orbital phase in the H-alpha profile. The H-beta profiles were consistent with the same effect. One hemisphere showed excess emission and the other excess absorption, with a broad Gaussian emission component superposed upon the excess H-alpha line. An improved radial velocity curve, giving a better determined mass ratio and geometry was derived. This combined with the radii implied by the rotational broadening of the spectra, showed one component to be 80 to 90% filling the equilibrium Roche surface. The two-faced nature is, therfore, very likely due to mass transfer from the contact component impacting upon its companion. Low resolution ultraviolet data showed that the supposed cooler component is bluer than its companion. High resolution ultraviolet data taken during secondary eclipse showed Mg II emission strength which decreased more slowly than the area visible. The phase behavior of the low resolution data support the former situation, indicating traditional chromospheric activity.

Optical and UV spectroscopy of the peculiar RS CVn system, RT Lacertae

NASA Astrophysics Data System (ADS)

Huenemoerder, D. P.; Barden, S. C.

1985-11-01

Spectra in the H-alpha and H-beta regions of the peculiar double-lined RS CVn binary, RT Lacertae, were obtained in the fall of 1984. Limited International Ultraviolet Explorer (IUE) long wavelength low and high resolution spectra were obtained concurrently. The ground based spectra have shown an asymmetry with orbital phase in the H-alpha profile. The H-beta profiles were consistent with the same effect. One hemisphere showed excess emission and the other excess absorption, with a broad Gaussian emission component superposed upon the excess H-alpha line. An improved radial velocity curve, giving a better determined mass ratio and geometry was derived. This combined with the radii implied by the rotational broadening of the spectra, showed one component to be 80 to 90% filling the equilibrium Roche surface. The two-faced nature is, therfore, very likely due to mass transfer from the contact component impacting upon its companion. Low resolution ultraviolet data showed that the supposed cooler component is bluer than its companion. High resolution ultraviolet data taken during secondary eclipse showed Mg II emission strength which decreased more slowly than the area visible. The phase behavior of the low resolution data support the former situation, indicating traditional chromospheric activity.

SS Bootis - A totally eclipsing binary of the RS CVn type

NASA Technical Reports Server (NTRS)

Vaucher, C. A.; Africano, J. L.; Henry, G. W.; Hall, D. S.; Wilson, J. W.

1983-01-01

Photoelectric photometry gathered for SS Bootis over the 1976-1981 period shows a distortion wave amplitude variation from 0.05 to 0.20 mag, with no apparent pattern. From the rectified light curve, a new time of midprimary eclipse was found to be 2444332.0335 + or - 0.0005 days. Solutions of the primary eclipse data, rectified for star spots as well as for ellipticity and reflection, are presented.

Clinical utility of calf front hoof circumference and maternal intrapelvic area in predicting dystocia in 103 late gestation Holstein-Friesian heifers and cows.

PubMed

Hiew, Mark W H; Megahed, Ameer A; Townsend, Jonathan R; Singleton, Wayne L; Constable, Peter D

2016-02-01

The objective of this study was to determine the clinical utility of measuring calf front hoof circumference, maternal intrapelvic area, and selected morphometric values in predicting dystocia in dairy cattle. An observational study using a convenience sample of 103 late-gestation Holstein-Friesian heifers and cows was performed. Intrapelvic height and width of the dam were measured using a pelvimeter, and the intrapelvic area was calculated. Calf front hoof circumference and birth weight were also measured. Data were analyzed using Spearman's correlation coefficient (rs), Mann-Whitney U test, and binary or ordered logistic regression; P < 0.05 was significant. The calving difficulty score (1-5) was greater in heifers (median, 3.0) than in cows (median, 1.0). Median intrapelvic area immediately before parturition was smaller in heifers (268 cm(2)) than in cows (332 cm(2)), whereas front hoof circumference and birth weight of the calf were similar in both groups. The calving difficulty score was positively associated with calf birth weight in heifers (rs = 0.39) and cows (rs = 0.24). Binary logistic regression using both dam and calf data indicated that the ratio of front hoof circumference of the calf to the maternal intrapelvic area provided the best predictor of dystocia (calving difficulty score = 4 or 5), with sensitivity = 0.50 and specificity = 0.93 at the optimal cutpoint for the ratio (>0.068 cm/cm(2)). Determining the ratio of calf front hoof circumference to maternal intrapelvic area has clinical utility in predicting the calving difficulty score in Holstein-Friesian cattle. Copyright © 2016 Elsevier Inc. All rights reserved.

Vitamin D receptor and megalin gene polymorphisms are associated with central adiposity status and changes among US adults.

PubMed

Beydoun, May A; Tanaka, Toshiko; Beydoun, Hind A; Ding, Eric L; Ferrucci, Luigi; Zonderman, Alan B

2013-01-01

We examined longitudinal associations of vitamin D receptor (VDR) and megalin (LRP2; LDL receptor-related protein-2) gene polymorphisms with central adiposity. We used data from the Baltimore Longitudinal Study of Aging (BLSA), an ongoing prospective open cohort study. Study participants consisted of non-Hispanic white adults residing in Baltimore city, with one or more visits at age ≥50 years, and complete data (n 609-617). Repeated assessments on waist circumference (WC) and waist:hip ratio (WHR) were available. Multiple linear mixed models were used to estimate mid-follow-up age central adiposity level and annual rate of change with cut-points set at the sex-specific 80th percentile. The four binary outcomes were: 'elevated central adiposity' (ECA-WC and ECA-WHR) and 'significant increase in central adiposity' (SICA-WC and SICA-WHR). SNP for VDR (four SNP: (1) rs11568820 (CdX-2:T/C); (2) rs1544410 (BsmI:G/A); (3) rs7975232 (ApaI:A/C); (4) rs731236 (TaqI:G/A)) and Megalin (three SNP: (1) rs3755166:G/A; (2) rs2075252:C/T; (3) rs4668123:C/T) genes were selected. SNP latent classes (SNPLC) and SNP haplotypes (SNPHAP) were created. Multiple logistic regression analyses indicated that, in men, higher ECA-WHR odds were associated with SNPLC Megalin2:rs3755166[-]/rs2075252[TT]/rs4668123[T-] (v. Megalin1:rs3755166[-]/rs2075252[CC]/rs4668123[-]) (OR 2·87; 95 % CI 1·15, 7·12; P = 0·023) and that SNPLC Megalin3:rs3755166[-]/rs2075252[CT]/rs4668123[-] (v. Megalin1) was linked to lower SICA-WC odds (OR 0·48; 95 % CI 0·26, 0·88; P = 0·019) (P > 0·05 for sex × SNPLC). In women, VDR3 SNPHAP (GAA:bAT) was related to lower odds of ECA-WC (OR 0·37; 95 % CI 0·16, 0·87; P = 0·023) (P < 0·05 for sex × SNPHAP), VDR1 SNPHAP (GCA:baT) was associated with greater odds and VDR3 SNPHAP (GAA:bAT) with lower odds of SICA-WC (P > 0·05 for sex × SNPHAP). Vitamin D-related gene polymorphisms were associated with central adiposity status and change. Future mechanistic studies are needed to confirm those polymorphisms' biological significance to central adiposity.

Extensive Evaluation of the Conductor-like Screening Model for Real Solvents Method in Predicting Liquid-Liquid Equilibria in Ternary Systems of Ionic Liquids with Molecular Compounds.

PubMed

Paduszyński, Kamil

2018-04-12

A conductor-like screening model for real solvents (COSMO-RS) is nowadays one of the most popular and commonly applied tools for the estimation of thermodynamic properties of complex fluids. The goal of this work is to provide a comprehensive review and analysis of the performance of this approach in calculating liquid-liquid equilibrium (LLE) phase diagrams in ternary systems composed of ionic liquid and two molecular compounds belonging to diverse families of chemicals (alkanes, aromatics, S/N-compounds, alcohols, ketones, ethers, carboxylic acid, esters, and water). The predictions are presented for extensive experimental database, including 930 LLE data sets and more than 9000 data points (LLE tie lines) reported for 779 unique ternary mixtures. An impact of the type of molecular binary subsystem on the accuracy of predictions is demonstrated and discussed on the basis of representative examples. The model's capability of capturing qualitative trends in the LLE distribution ratio and selectivity is also checked for a number of structural effects. Comparative analysis of two levels of quantum chemical theory (BP-TZVP-COSMO vs BP-TZVPD-FINE) for the input molecular data for COSMO-RS is presented. Finally, some general recommendations for the applicability of the model are indicated based on the analysis of the global performance as well as on the results obtained for systems relevant from the point of view of important separation problems.

The assessment of the relationship between variations in the apelin gene and coronary artery disease in Turkish population.

PubMed

Pakizeh, Ebrahim; Çoşkunpınar, Ender; Oltulu, Yasemin Müşteri; Çakmak, Hüseyin Altuğ; İkitimur, Barış; Işık Sağlam, Zümrüt Mine; Karimova, Ayla; Vural, Vural Ali

2015-09-01

Apelin is a novel endogenous peptide with inotropic and vasodilatory properties and is the ligand for the angiotensin receptor-like 1 (APJ) receptor. The aim of the study was to investigate the association of 2 single-nucleotide polymorphisms (SNPs) in the apelin gene with susceptibility to coronary artery disease (CAD) in the Turkish population. The present observational case-control study consisted of 244 subjects (134 angiographically proven CAD patients and 110 healthy controls) aged 30-65 years. The association of 2 SNPs (rs3115758 and rs3115759) in the apelin gene and CAD risk was investigated. Real-time polymerase chain reaction (RT-PCR) was used to analyze the 2 SNPs in both the CAD and the healthy subjects. Allele and genotype frequencies between patients and control groups were compared using the Chi-square (χ2) test. The relationships of the 2 polymorphisms with the presence of CAD were determined with multiple binary logistic regression analysis after adjustment for CAD risk factors. TT and AA risk genotypes of the rs3115758 and rs3115759 variants in the apelin gene were found to be significantly related with the risk of CAD with the same power (OR: 6.36, 95% CI: 1.41-28.6) (p=0.007). After adjustments for traditional CAD risk factors, the homozygous TT genotype for rs3115758 and AA genotype for rs3115759 increased the CAD risk, both with an OR of 5.91. Genetic variants in the apelin gene are significantly associated with the risk of CAD in the Turkish population.

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

Geller, Aaron M.; Leiner, Emily M.; Mathieu, Robert D.

Sub-subgiants are stars that are observed to be redder than normal main-sequence stars and fainter than normal subgiant (and giant) stars in an optical color–magnitude diagram (CMD). The red straggler stars, which lie redward of the red giant branch, may be related and are often grouped together with the sub-subgiants in the literature. These stars defy our standard theory of single-star evolution and are important tests for binary evolution and stellar collision models. In total, we identify 65 sub-subgiants (SSG) and red stragglers (RS) in 16 open and globular star clusters from the literature; 50 of these, including 43 sub-subgiants,more » pass our strict membership selection criteria (though the remaining sources may also be cluster members). In addition to their unique location on the CMD, we find that at least 58% (25/43) of sub-subgiants in this sample are X-ray sources with typical 0.5–2.5 keV luminosities of order 10{sup 30}–10{sup 31} erg s{sup −1}. Their X-ray luminosities and optical–to–X-ray flux ratios are similar to those of RS CVn active binaries. At least 65% (28/43) of the sub-subgiants in our sample are variables, 21 of which are known to be radial-velocity binaries. Typical variability periods are ≲15 days. At least 33% (14/43) of the sub-subgiants are H α emitters. These observational demographics provide strong evidence that binarity is important for sub-subgiant formation. Finally, we find that the number of sub-subgiants per unit mass increases toward lower-mass clusters, such that the open clusters in our sample have the highest specific frequencies of sub-subgiants.« less

Complexation equilibria and coordination aspects of Zn(II) complexes contain 2-aminobenzamide and some bioactive amino acid mixed ligands: pH-metric, spectroscopic and thermodynamic studies.

PubMed

Dharmaraja, Jeyaprakash; Subbaraj, Paramasivam; Esakkidurai, Thirugnanasamy; Shobana, Sutha; Raji, Saravanan

2014-01-01

Mixed ligand complexation of 2-aminobenzamide (2AB) as ligand [L] with Zn(II) in the presence of some bio-relevant amino acid constituents like glycine (gly), L-alanine (ala), L-valine (val) and L-phenylalanine (phe) as ligand [B] have been investigated using pH-metric measurements with a combined pH electrode at different temperatures (300, 310, 320 and 330 ± 0.1 K) in 50% (v/v) ethanol-water mixture containing I = 0.15 M NaClO(4) as supporting electrolyte. Computer assisted analysis of the experimental titration data showed the presence of ZnLB and ZnLB2 species as mixed ligand complexes in addition to various binary species. In ZnLB/ZnLB(2) species, both primary and secondary ligands act as bidentate to form a stable six, five membered chelate ring. The calculated stabilization parameter Deltalog K, log X, log X' and % R.S. values clearly show the mixed ligand complexes have higher stabilities than their binary. Thermodynamic parameters DeltaG, DeltaH and DeltaS have been derived from the temperature dependence of the stability constants. The complexation behavior of ZnLB species has been studied by means of electronic spectra. The percentage distribution of various binary and mixed ligand species of each type of the complexes in solution depending on pH and the ratio of Zn(II) to 2-aminobenzamide/amino acid of the systems.

Infrared spectroscopy of the remnant of Nova Sco 2014: a symbiotic star with too little circumstellar matter to decelerate the ejecta

NASA Astrophysics Data System (ADS)

Munari, U.; Banerjee, D. P. K.

2018-03-01

Pre-outburst 2MASS and WISE photometry of Nova Sco 2014 (V1534 Sco) has suggested the presence of a cool giant at the location of the nova in the sky. The spectral evolution recorded for the nova did not, however, support a direct partnership because no flash-ionized wind and no deceleration of the ejecta were observed, contrary to the behaviour displayed by other novae which erupted within symbiotic binaries like V407 Cyg or RS Oph. We have therefore obtained 0.8-2.5 μm spectra of the remnant of Nova Sco 2014 in order to ascertain if a cool giant is indeed present and if it is physically associated with the nova. The spectrum shows the presence of a M6III giant, reddened by E(B - V) = 1.20, displaying the typical and narrow emission-line spectrum of a symbiotic star, including He I 1.0830 μm with a deep P-Cyg profile. This makes Nova Sco 2014 a new member of the exclusive club of novae that erupt within a symbiotic binary. Nova Sco 2014 shows that a nova erupting within a symbiotic binary does not always come with a deceleration of the ejecta, contrary to the common belief. Many other similar systems may lay hidden in past novae, especially in those that erupted prior to the release of the 2MASS all-sky infrared survey, which could be profitably cross-matched now against them.

Copernicus observations of neutral hydrogen and deuterium in the direction of HR 1099

NASA Technical Reports Server (NTRS)

Anderson, R. C.; Weiler, E. J.

1979-01-01

High-resolution Copernicus U1 scans were obtained of the bright RS CVn binary HR 1099 (d = 33 pc, galactic longitude = 185 deg, galactic latitude = -41 deg) in October 1977. Strong emission at L-alpha was detected. The interstellar L-alpha absorption features of H I and D I were also observed. Analyses of these interstellar lines are reported in this paper. The average density of neutral H in the direction of this system is found to be 0.006-0.012 per cu cm, which, because the local density is higher, requires a marked inhomogeneity along this line of sight. This result, when combined with other recent studies of the local interstellar medium, suggests the sun is located within a moderate-density H I region.

Oral cancer screening: serum Raman spectroscopic approach

NASA Astrophysics Data System (ADS)

Sahu, Aditi K.; Dhoot, Suyash; Singh, Amandeep; Sawant, Sharada S.; Nandakumar, Nikhila; Talathi-Desai, Sneha; Garud, Mandavi; Pagare, Sandeep; Srivastava, Sanjeeva; Nair, Sudhir; Chaturvedi, Pankaj; Murali Krishna, C.

2015-11-01

Serum Raman spectroscopy (RS) has previously shown potential in oral cancer diagnosis and recurrence prediction. To evaluate the potential of serum RS in oral cancer screening, premalignant and cancer-specific detection was explored in the present study using 328 subjects belonging to healthy controls, premalignant, disease controls, and oral cancer groups. Spectra were acquired using a Raman microprobe. Spectral findings suggest changes in amino acids, lipids, protein, DNA, and β-carotene across the groups. A patient-wise approach was employed for data analysis using principal component linear discriminant analysis. In the first step, the classification among premalignant, disease control (nonoral cancer), oral cancer, and normal samples was evaluated in binary classification models. Thereafter, two screening-friendly classification approaches were explored to further evaluate the clinical utility of serum RS: a single four-group model and normal versus abnormal followed by determining the type of abnormality model. Results demonstrate the feasibility of premalignant and specific cancer detection. The normal versus abnormal model yields better sensitivity and specificity rates of 64 and 80% these rates are comparable to standard screening approaches. Prospectively, as the current screening procedure of visual inspection is useful mainly for high-risk populations, serum RS may serve as a useful adjunct for early and specific detection of oral precancers and cancer.

V405 ANDROMEDA REVISITED

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

Ribeiro, T.; Baptista, R.; Kafka, S.

We present a multi-epoch time-resolved high-resolution optical spectroscopy study of the short-period (P{sub orb} = 11.2 hr) eclipsing M0V+M5V RS CVn binary V405 Andromeda. By means of indirect imaging techniques, namely Doppler imaging, we study the surface activity features of the M0V component of the system. A modified version of a Doppler imaging code, which takes into account the tidal distortion of the surface of the star, is applied to the multi-epoch data set in order to provide indirect images of the stellar surface. The multi-epoch surface brightness distributions show a low intensity 'belt' of spots at latitudes {+-}40{sup 0}more » and a noticeable absence of high latitude features or polar spots on the primary star of V405 Andromeda. They also reveal slow evolution of the spot distribution over {approx}4 yr. An entropy landscape procedure is used in order to find the set of binary parameters that lead to the smoothest surface brightness distributions. As a result, we find M{sub 1} = 0.51 {+-} 0.03 M{sub sun}, M{sub 2} = 0.21 {+-} 0.01 M{sub sun}, R{sub 1} = 0.71 {+-} 0.01 R{sub sun}, and an inclination i = 65{sup 0} {+-} 1{sup 0}. The resulting systemic velocity is distinct for different epochs, raising the possibility of the existence of a third body in the system.« less

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

Kim, Chun-Hwey; Song, Mi-Hwa; Yoon, Jo-Na

A photometric study of BD And was made through the analysis of two sets of new BVR light curves. The light curves with migrating photometric waves outside eclipse show that BD And is a short-period RS CVn-type binary star. The analysis of all available timings reveals that the orbital period has varied in a strictly cyclical way with a period of 9.2 yr. The periodic variation most likely arises from the light-time effect due to a tertiary moving in a highly elliptical orbit (e {sub 3} = 0.76). The Applegate mechanism could not operate properly in the eclipsing pair. Themore » light curves were modeled with two large spots on the hotter star and a large third light amounting to about 14% of the total systemic light. BD And is a triple system: a detached binary system consisting of two nearly equal solar-type stars with an active primary star and a G6-G7 tertiary dwarf. The absolute dimensions of the eclipsing pair and tertiary components were determined. The three components with a mean age of about 5.8 Gyr are located at midpositions in main-sequence bands. The radius of the secondary is about 17% larger than that deduced from stellar models. The orbital and radiometric characteristics of the tertiary are intensively investigated. One important feature is that the mutual inclination between two orbits is larger than 60°, implying that Kozai cycles had occurred very efficiently in the past. The possible past and future evolutions of the BD And system, driven by KCTF and MBTF, are also discussed.« less

Association of HS6ST3 gene polymorphisms with obesity and triglycerides: gene x gender interaction.

PubMed

Wang, Ke-Sheng; Wang, Liang; Liu, Xuefeng; Zeng, Min

2013-12-01

The heparan sulfate 6-O-sulfotransferase 3 (HS6ST3) gene is involved in heparan sulphate and heparin metabolism, and has been reported to be associated with diabetic retinopathy in type 2 diabetes.We hypothesized that HS6ST3 gene polymorphisms might play an important role in obesity and related phenotypes (such as triglycerides). We examined genetic associations of 117 single-nucleotide polymorphisms (SNPs) within the HS6ST3 gene with obesity and triglycerides using two Caucasian samples: the Marshfield sample (1442 obesity cases and 2122 controls), and the Health aging and body composition (Health ABC) sample (305 cases and 1336 controls). Logistic regression analysis of obesity as a binary trait and linear regression analysis of triglycerides as a continuous trait, adjusted for age and sex, were performed using PLINK. Single marker analysis showed that six SNPs in the Marshfield sample and one SNP in the Health ABC sample were associated with obesity (P < 0.05). SNP rs535812 revealed a stronger association with obesity in meta-analysis of these two samples (P = 0.0105). The T-A haplotype from rs878950 and rs9525149 revealed significant association with obesity in the Marshfield sample (P = 0.012). Moreover, nine SNPs showed associations with triglycerides in the Marshfield sample (P < 0.05) and the best signal was rs1927796 (P = 0.00858). In addition, rs7331762 showed a strong gene x gender interaction (P = 0.00956) for obesity while rs1927796 showed a strong gene x gender interaction (P = 0.000625) for triglycerides in the Marshfield sample. These findings contribute new insights into the pathogenesis of obesity and triglycerides and demonstrate the importance of gender differences in the aetiology.

Goddard High Resolution Spectrograph Observations of Variability in the RS Canum Venaticorum System V711 Tauri (HR 1099)

NASA Technical Reports Server (NTRS)

Dempsey, Robert C.; Neff, James E.; Thorpe, Marjorie J.; Linsky, Jeffrey L.; Brown, Alexander; Cutispoto, Giuseppe; Rodono, Marcello

1996-01-01

Goddard High Resolution Spectrograph (GHRS) observations of the RS CVn-type binary V711 Tau (Kl IV+G5 IV) were obtained at several phases over two consecutive stellar orbital cycles in order to study ultraviolet emission-line profile and flux variability. Spectra cover the Mg II h and k lines, C IV doublet, and Si IV region, as well as the density-sensitive lines of C III] (1909 A) and Si III] (1892 A). IUE spectra, Extreme Ultra Violet (EUV) data, and Ultraviolet, Blue, Visual (UBV) photometry were obtained contemporaneously with the GHRS data. Variable extended wings were detected in the Mg II lines. We discuss the Mg II line profile variability using various Gaussian emission profile models. No rotational modulation of the line profiles was observed, but there were several large flares. These flares produced enhanced emission in the extended line wings, radial velocity shifts, and asymmetries in some line profiles. Nearly continuous flaring for more than 24 hr, as indicated in the IUE data, represents the most energetic and long-lived chromospheric and transition region flare ever observed with a total energy much greater than 5 x 10(exp 35) ergs. The C III] to Si III] line ratio is used to estimate the plasma density during the flares.

Novel spectrophotometric methods for simultaneous determination of timolol and dorzolamide in their binary mixture.

PubMed

Lotfy, Hayam Mahmoud; Hegazy, Maha A; Rezk, Mamdouh R; Omran, Yasmin Rostom

2014-05-21

Two smart and novel spectrophotometric methods namely; absorbance subtraction (AS) and amplitude modulation (AM) were developed and validated for the determination of a binary mixture of timolol maleate (TIM) and dorzolamide hydrochloride (DOR) in presence of benzalkonium chloride without prior separation, using unified regression equation. Additionally, simple, specific, accurate and precise spectrophotometric methods manipulating ratio spectra were developed and validated for simultaneous determination of the binary mixture namely; simultaneous ratio subtraction (SRS), ratio difference (RD), ratio subtraction (RS) coupled with extended ratio subtraction (EXRS), constant multiplication method (CM) and mean centering of ratio spectra (MCR). The proposed spectrophotometric procedures do not require any separation steps. Accuracy, precision and linearity ranges of the proposed methods were determined and the specificity was assessed by analyzing synthetic mixtures of both drugs. They were applied to their pharmaceutical formulation and the results obtained were statistically compared to that of a reported spectrophotometric method. The statistical comparison showed that there is no significant difference between the proposed methods and the reported one regarding both accuracy and precision. Copyright © 2014 Elsevier B.V. All rights reserved.

RS3PE revisited: a systematic review and meta-analysis of 331 cases.

PubMed

Karmacharya, Paras; Donato, Anthony A; Aryal, Madan R; Ghimire, Sushil; Pathak, Ranjan; Shah, Kalpana; Shrestha, Pragya; Poudel, Dilli; Wasser, Thomas; Subedi, Ananta; Giri, Smith; Jalota, Leena; Olivé, Alejandro

2016-01-01

Remitting seronegative symmetrical synovitis with pitting oedema (RS(3)PE) syndrome is a rare inflammatory arthritis, characterised by symmetrical distal synovitis, pitting oedema of the hands and feet, absence of rheumatoid factor, and favourable response to glucocorticoids. The aim of our study is to further delineate the clinical and laboratory features, and response to treatment. We performed a systematic electronic search of Medline, PubMed, EMBASE, ACR and EULAR databases for case reports, case series, and related articles of RS(3)PE. Statistical analysis was done comparing categorical variables with Chi-square tests and frequencies of means via t-tests. Binary logistic regression analysis was performed to identify predictors of erosions, recurrence, malignancy and rheumatologic disorders. 331 cases of RS(3)PE were identified from 121 articles. RS(3)PE was found in older patients (71±10.42 years) predominantly in males (n= 211, 63.36%), was symmetrical (n=297/311, 95.50%) involved the hands (n=294/311, 94.53%) A concurrent rheumatologic condition was reported in 22 cases (6.65%), and malignancy in 54 cases (16.31%). Radiographic joint erosions were found in 5.5%. Most patients responded to medium-dose glucocorticoids (16.12±9.5 mg/day). Patients with concurrent malignancy requiring non-significantly higher doses of prednisone (18.12 vs. 15.76 mg, p 0.304) and higher likelihood of recurrence of disease (OR 4.04, 95% CI 1.10-14.88, p=0.03). The symptoms and unique findings that make up RS(3)PE appear to represent a steroid-responsive disease that may be a harbinger of an underlying malignancy. More study is needed to understand the molecular origins of RS(3)PE in order to determine whether it is a separate disease process. Patients with concurrent cancer tend to have more severe presentations and higher rates of recurrence.

Requirement of the CroRS Two-Component System for Resistance to Cell Wall-Targeting Antimicrobials in Enterococcus faecium.

PubMed

Kellogg, Stephanie L; Little, Jaime L; Hoff, Jessica S; Kristich, Christopher J

2017-05-01

Enterococci are serious opportunistic pathogens that are resistant to many cell wall-targeting antibiotics. The CroRS two-component signaling system responds to antibiotic-mediated cell wall stress and is critical for resistance to cell wall-targeting antibiotics in Enterococcus faecalis Here, we identify and characterize an orthologous two-component system found in Enterococcus faecium that is functionally equivalent to the CroRS system of E. faecalis Deletion of croRS in E. faecium resulted in marked susceptibility to cell wall-targeting agents including cephalosporins and bacitracin, as well as moderate susceptibility to ampicillin and vancomycin. As in E. faecalis , exposure to bacitracin and vancomycin stimulates signaling through the CroRS system in E. faecium Moreover, the CroRS system is critical in E. faecium for enhanced beta-lactam resistance mediated by overexpression of Pbp5. Expression of a Pbp5 variant that confers enhanced beta-lactam resistance cannot overcome the requirement for CroRS function. Thus, the CroRS system is a conserved signaling system that responds to cell wall stress to promote intrinsic resistance to important cell wall-targeting antibiotics in clinically relevant enterococci. Copyright © 2017 American Society for Microbiology.

Requirement of the CroRS Two-Component System for Resistance to Cell Wall-Targeting Antimicrobials in Enterococcus faecium

PubMed Central

Kellogg, Stephanie L.; Little, Jaime L.; Hoff, Jessica S.

2017-01-01

ABSTRACT Enterococci are serious opportunistic pathogens that are resistant to many cell wall-targeting antibiotics. The CroRS two-component signaling system responds to antibiotic-mediated cell wall stress and is critical for resistance to cell wall-targeting antibiotics in Enterococcus faecalis. Here, we identify and characterize an orthologous two-component system found in Enterococcus faecium that is functionally equivalent to the CroRS system of E. faecalis. Deletion of croRS in E. faecium resulted in marked susceptibility to cell wall-targeting agents including cephalosporins and bacitracin, as well as moderate susceptibility to ampicillin and vancomycin. As in E. faecalis, exposure to bacitracin and vancomycin stimulates signaling through the CroRS system in E. faecium. Moreover, the CroRS system is critical in E. faecium for enhanced beta-lactam resistance mediated by overexpression of Pbp5. Expression of a Pbp5 variant that confers enhanced beta-lactam resistance cannot overcome the requirement for CroRS function. Thus, the CroRS system is a conserved signaling system that responds to cell wall stress to promote intrinsic resistance to important cell wall-targeting antibiotics in clinically relevant enterococci. PMID:28223383

The Role of Grain Boundary Chemistry and the Environment on Intergranular Fracture.

DTIC Science & Technology

1980-10-01

and alloys as well. Grain boundary segregation of phosphorus, for example, has been observed in thermally treated nickel-base alloys such as Inconel ...base alloys such as Inconel 600 and Hastelloy C-276. Hence, Ni-P binary glasses may be considered to be good structural and chemical analog of grain...p. 625 17. H.W. Pickering and M. Zamanzedeh: This Conference, Poster Session 18. B.J. Berkowitz, J.J. Burton, C.R. Helms and R.S. Polizzotti

Constraining the braneworld with gravitational wave observations.

PubMed

McWilliams, Sean T

2010-04-09

Some braneworld models may have observable consequences that, if detected, would validate a requisite element of string theory. In the infinite Randall-Sundrum model (RS2), the AdS radius of curvature, l, of the extra dimension supports a single bound state of the massless graviton on the brane, thereby reproducing Newtonian gravity in the weak-field limit. However, using the AdS/CFT correspondence, it has been suggested that one possible consequence of RS2 is an enormous increase in Hawking radiation emitted by black holes. We utilize this possibility to derive two novel methods for constraining l via gravitational wave measurements. We show that the EMRI event rate detected by LISA can constrain l at the approximately 1 microm level for optimal cases, while the observation of a single galactic black hole binary with LISA results in an optimal constraint of l < or = 5 microm.

Constraining the Braneworld with Gravitational Wave Observations

NASA Technical Reports Server (NTRS)

McWilliams, Sean T.

2011-01-01

Some braneworld models may have observable consequences that, if detected, would validate a requisite element of string theory. In the infinite Randall-Sundrum model (RS2), the AdS radius of curvature, L, of the extra dimension supports a single bound state of the massless graviton on the brane, thereby reproducing Newtonian gravity in the weak-field limit. However, using the AdS/CFT correspondence, it has been suggested that one possible consequence of RS2 is an enormous increase in Hawking radiation emitted by black holes. We utilize this possibility to derive two novel methods for constraining L via gravitational wave measurements. We show that the EMRI event rate detected by LISA can constrain L at the approximately 1 micron level for optimal cases, while the observation of a single galactic black hole binary with LISA results in an optimal constraint of L less than or equal to 5 microns.

Chromospherically active stars. III - HD 26337 = EI Eri: An RS CVn candidate for the Doppler-imaging technique

NASA Technical Reports Server (NTRS)

Fekel, Francis C.; Quigley, Robert; Gillies, Kim; Africano, John L.

1987-01-01

Spectroscopic observations of the chromospherically active G5 IV single-lined binary HD 26337 = EI Eri are presented. An orbital period of 1.94722 days is found for the star. It has moderately strong Ca II H and K emission and strong ultraviolet emission features, while H-alpha is a weak absorption feature that is variable in strength. The inclination of the system is 46 + or - 12 deg, and the unseen secondary is probably a late K or early M dwarf. The v sin i of the primary is 50 + or - 3 km/s, resulting in a minimum radius of 1.9 + or - 0.1 solar radius. The star is within the required limits for Doppler imaging. The primary is close to filling its Roche lobe, resulting in a strong constraint that the mass ratio is 2.6 or greater, with a primary mass of at least 1.4 solar mass. The distance to the system is estimated at 75 pc.

Glucagon gene polymorphism modifies the effects of smoking and physical activity on risk of type 2 diabetes mellitus in Han Chinese.

PubMed

Li, Linlin; Gao, Kaiping; Zhao, Jingzhi; Feng, Tianping; Yin, Lei; Wang, Jinjin; Wang, Chongjian; Li, Chunyang; Wang, Yan; Wang, Qian; Zhai, Yujia; You, Haifei; Ren, Yongcheng; Wang, Bingyuan; Hu, Dongsheng

2014-01-25

Few genome-wide association studies have considered interactions between multiple genetic variants and environmental factors associated with disease. The interaction was examined between a glucagon gene (GCG) polymorphism and smoking, alcohol consumption and physical activity and the association with risk of type 2 diabetes mellitus (T2DM) in a case-control study of Chinese Han subjects. The rs12104705 polymorphism of GCG and interactions with environmental variables were analyzed for 9619 participants by binary multiple logistic regression. Smoking with the C-C haplotype of rs12104705 was associated with increased risk of T2DM (OR=1.174, 95% CI=1.013-1.361). Moderate and high physical activity with the C-C genotype was associated with decreased risk of T2DM as compared with low physical activity with the genotype (OR=0.251, 95% CI=0.206-0.306 and OR=0.190, 95% CI=0.164-0.220). However, the interaction of drinking and genotype was not associated with risk of T2DM. Genetic polymorphism in rs12104705 of GCG may interact with smoking and physical activity to modify the risk of T2DM. © 2013.

RS-34 (Peacekeeper Post Boost Propulsion System) Orbital Debris Application Concept Study

NASA Technical Reports Server (NTRS)

Esther, Elizabeth A.; Burnside, Christopher G.

2013-01-01

The Advanced Concepts Office (ACO) at the NASA Marshall Space Flight Center (MSFC) lead a study to evaluate the Rocketdyne produced RS-34 propulsion system as it applies to an orbital debris removal design reference mission. The existing RS-34 propulsion system is a remaining asset from the de-commissioned United States Air Force Peacekeeper ICBM program; specifically the pressure-fed storable bi-propellant Stage IV Post Boost Propulsion System. MSFC gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. Subsequently, MSFC is working closely with the USAF to obtain all the remaining RS-34 stages for re-use opportunities. Prior to pursuit of securing the hardware, MSFC commissioned the Advanced Concepts Office to understand the capability and potential applications for the RS-34 Phoenix stage as it benefits NASA, DoD, and commercial industry. Originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy multiple payloads at various orbital locations. The RS-34 Concept Study, preceded by a utilization study to understand how the unique capabilities of the RS-34 Phoenix and its application to six candidate missions, sought to further understand application for an orbital debris design reference mission as the orbital debris removal mission was found to closely mimic the heritage RS-34 mission. The RS-34 Orbital Debris Application Concept Study sought to identify multiple configurations varying the degree of modification to trade for dry mass optimization and propellant load for overall capability and evaluation of several candidate missions. The results of the RS-34 Phoenix Utilization Study show that the system is technically sufficient to successfully support all of the missions analyzed. The results and benefits of the RS-34 Orbital Debris Application Concept Study are presented in this paper.

Description of the behavior of dichloroalkanes-containing solutions with three [bXmpy][BF4] isomers, using the experimental information of thermodynamic properties, 1H NMR spectral and the COSMO-RS-methodology.

PubMed

Fernández, Luis; Ortega, Juan; Palomar, José; Toledo, Francisco; Marrero, Elena

2015-02-26

This work studies the binaries of 1-butyl-X-methylpyridinium tetrafluoroborate [bXmpy][BF4] (X = 2, 3, and 4) with four 1,ω-dichloroalkanes, ω = 1-4, using the results obtained for the mixing properties h(E) and v(E) at two temperatures. The three isomers of the ionic liquid (IL) are weakly miscible with the 1,ω-dichloroalkanes when ω ≥ 5 and moderately soluble for ω = 4. The v(E)s of all the binaries present contractive effects, v(E) < 0, which are more pronounced with increasing temperature; the variation in v(E) with ω is positive, although this changes after ω = 4 due to problems of immiscibility. The energetic effects of the mixing process are exothermic in the solutions with the shorter dichloroalkanes, ω = 1 and 2, and this effect increases slightly with temperature. However, mildly exothermic effects are found in the binaries with larger halides, where (dh(E)/dT) > 0. The experimental data are correlated with a suitable equation. The study is completed with (1)H NMR measurements of both the pure compounds and some of the solutions, which showed minor diamagnetic shifts with increasing IL compositions, related to the anisotropy of the pyridine ring. The variation in h(E) with ω for a same IL, due to an increase in the contact surfaces, is related to the reduction in polarity which, in turn, depends on the smaller chemical shifts of the pure dihalide compounds. The COSMO-RS method determines the energetic effects of the mixing process and predicts an exothermic contribution for the electrostatic Misfit-interaction which is quantitatively very similar for the three IL isomers. The differences proposed by the model are mainly reflected in the van der Waals interactions, which are exothermic and clearly influenced by the position of the methylene group in the IL. The contribution made by hydrogen bonds is negligible.

RS-34 Phoenix (Peacekeeper Post Boost Propulsion System) Utilization Study

NASA Technical Reports Server (NTRS)

Esther, Elizabeth A.; Kos, Larry; Bruno, Cy

2012-01-01

The Advanced Concepts Office (ACO) at the NASA Marshall Space Flight Center (MSFC) in conjunction with Pratt & Whitney Rocketdyne conducted a study to evaluate potential in-space applications for the Rocketdyne produced RS-34 propulsion system. The existing RS-34 propulsion system is a remaining asset from the decommissioned United States Air Force Peacekeeper ICBM program; specifically the pressure-fed storable bipropellant Stage IV Post Boost Propulsion System, renamed Phoenix. MSFC gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in October 2009. RS-34 propulsion system components were harvested from stages supplied by the USAF and used on the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. Subsequently, MSFC is working closely with the USAF to obtain all the remaining RS-34 stages for re-use opportunities. Prior to pursuit of securing the hardware, MSFC commissioned the Advanced Concepts Office to understand the capability and potential applications for the RS-34 Phoenix stage as it benefits NASA, DoD, and commercial industry. Originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy multiple payloads at various orbital locations. The RS-34 Phoenix Utilization Study sought to understand how the unique capabilities of the RS-34 Phoenix and its application to six candidate missions: 1) small satellite delivery (SSD), 2) orbital debris removal (ODR), 3) ISS re-supply, 4) SLS kick stage, 5) manned GEO servicing precursor mission, and an Earth-Moon L-2 Waypoint mission. The small satellite delivery and orbital debris removal missions were found to closely mimic the heritage RS-34 mission. It is believed that this technology will enable a small, low-cost multiple satellite delivery to multiple orbital locations with a single boost. For both the small satellite delivery and the orbital debris mission candidates, the RS-34 Phoenix requires the least amount of modification to the existing hardware. The results of the RS-34 Phoenix Utilization Study show that the system is technically sufficient to successfully support all of the missions analyzed

RS-34 Phoenix (Peacekeeper Post Boost Propulsion System) Utilization Study

NASA Technical Reports Server (NTRS)

Esther, Elizabeth A.; Kos, Larry; Burnside, Christopher G.; Bruno, Cy

2013-01-01

The Advanced Concepts Office (ACO) at the NASA Marshall Space Flight Center (MSFC) in conjunction with Pratt & Whitney Rocketdyne conducted a study to evaluate potential in-space applications for the Rocketdyne produced RS-34 propulsion system. The existing RS-34 propulsion system is a remaining asset from the de-commissioned United States Air Force Peacekeeper ICBM program, specifically the pressure-fed storable bipropellant Stage IV Post Boost Propulsion System, renamed Phoenix. MSFC gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in October 2009. RS-34 propulsion system components were harvested from stages supplied by the USAF and used on the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. MSFC is working closely with the USAF to obtain RS-34 stages for re-use opportunities. Prior to pursuit of securing the hardware, MSFC commissioned the Advanced Concepts Office to understand the capability and potential applications for the RS-34 Phoenix stage as it benefits NASA, DoD, and commercial industry. As originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy multiple payloads at various orbital locations. The RS-34 Phoenix Utilization Study sought to understand how the unique capabilities of the RS-34 Phoenix and its application to six candidate missions: 1) small satellite delivery (SSD), 2) orbital debris removal (ODR), 3) ISS re-supply, 4) SLS kick stage, 5) manned GEO servicing precursor mission, and an Earth-Moon L-2 Waypoint mission. The small satellite delivery and orbital debris removal missions were found to closely mimic the heritage RS-34 mission. It is believed that this technology will enable a small, low-cost multiple satellite delivery to multiple orbital locations with a single boost. For both the small satellite delivery and the orbital debris mission candidates, the RS-34 Phoenix requires the least amount of modification to the existing hardware. The results of the RS-34 Phoenix Utilization Study show that the system is technically sufficient to successfully support all of the missions analyzed.

Radiation Segmentectomy versus TACE Combined with Microwave Ablation for Unresectable Solitary Hepatocellular Carcinoma Up to 3 cm: A Propensity Score Matching Study.

PubMed

Biederman, Derek M; Titano, Joseph J; Bishay, Vivian L; Durrani, Raisa J; Dayan, Etan; Tabori, Nora; Patel, Rahul S; Nowakowski, Francis S; Fischman, Aaron M; Kim, Edward

2017-06-01

Purpose To compare the outcomes of radiation segmentectomy (RS) and transarterial chemoembolization (TACE) combined with microwave ablation (MWA) in the treatment of unresectable solitary hepatocellular carcinoma (HCC) up to 3 cm. Materials and Methods This retrospective study was approved by the institutional review board, and the requirement to obtain informed consent was waived. From January 2010 to June 2015, a total of 417 and 235 consecutive patients with HCC underwent RS and TACE MWA, respectively. A cohort of 121 patients who had not previously undergone local-regional therapy (RS, 41; TACE MWA, 80; mean age, 65.4 years; 84 men [69.4%]) and who had solitary HCC up to 3 cm without vascular invasion or metastasis was retrospectively identified. Outcomes analyzed included procedure-related complications, laboratory toxicity levels, imaging response, time to progression (TTP), 90-day mortality, and survival. Propensity score matching was conducted by using a nearest-neighbor algorithm (1:1) to account for pretreatment clinical, laboratory, and imaging covariates. Postmatching statistical analysis was performed with conditional logistic regression for binary outcomes and the stratified log-rank test for time-dependent outcomes. Results Before matching, the complication rate was 8.9% and 4.9% in the TACE MWA and RS groups, respectively (P = .46). The overall complete response (CR) rate was 82.9% for RS and 82.5% for TACE MWA (odds ratio, 1.0; 95% confidence interval [CI]: 0.4, 2.8; P = .95). There were 41 (RS, 11; TACE MWA, 30) instances of progression occurring after an initial CR, of which 10 (24%) were classified as target progression (RS, one; TACE MWA, nine). Median overall TTP was 11.1 months (95% CI: 8.8 months, 25.6 months) in the RS group and 12.1 months (95% CI: 7.7 months, 19.1 months) in the TACE MWA group (P > .99). After matching, the overall CR rate (P = .94), TTP (P = .83), and overall survival (P > .99) were not significantly different between the two groups. The 90-day postoperative mortality rate was 0% in both groups. Conclusion Imaging response and progression outcomes of patients with solitary HCC up to 3 cm treated with RS were not significantly different when compared with those of patients treated with TACE MWA. © RSNA, 2016 Online supplemental material is available for this article.

Einstein Observatory magnitude-limited X-ray survey of late-type giant and supergiant stars

NASA Technical Reports Server (NTRS)

Maggio, A.; Vaiana, G. S.; Haisch, B. M.; Stern, R. A.; Bookbinder, J.

1990-01-01

Results are presented of an extensive X-ray survey of 380 giant and supergiant stars of spectral types from F to M, carried out with the Einstein Observatory. It was found that the observed F giants or subgiants (slightly evolved stars with a mass M less than about 2 solar masses) are X-ray emitters at the same level of main-sequence stars of similar spectral type. The G giants show a range of emissions more than 3 orders of magnitude wide; some single G giants exist with X-ray luminosities comparable to RS CVn systems, while some nearby large G giants have upper limits on the X-ray emission below typical solar values. The K giants have an observed X-ray emission level significantly lower than F and F giants. None of the 29 M giants were detected, except for one spectroscopic binary.

Relationship between the rs1414334 C/G polymorphism in the HTR2C gene and smoking in patients treated with atypical antipsychotics.

PubMed

Rico-Gomis, José María; Palazón-Bru, Antonio; Triano-García, Irene; Mahecha-García, Luis Fabián; García-Monsalve, Ana; Navarro-Ruiz, Andrés; Villagordo-Peñalver, Berta; Martínez-Hortelano, Alicia; Gil-Guillén, Vicente Francisco

2018-04-15

An association has been found between the C allele of the rs1414334 polymorphism in the HTR2C gene and the metabolic syndrome in psychiatric patients. However, no study has yet evaluated whether this allele is associated with smoking. To assess this issue, therefore, we performed a cross-sectional study with a sample of 166 adult patients treated with atypical antipsychotics in 2012-2013 in a region of Spain. The primary variable was the presence of the C allele of the rs1414334 polymorphism in the HTR2C gene. Secondary variables were the number of pack-years (number of cigarettes per day x number of smoking years ÷ 20), age, gender, schizophrenia, years since diagnosis, metabolic syndrome criteria and SCORE. A stepwise binary logistic regression model was constructed to determine associations between primary and secondary variables and their area under the ROC curve (AUC) was calculated. Of the total sample, 33 patients (19.9%) had the C allele of the polymorphism analyzed. Mean cigarette consumption was 11.6 pack-years. The multivariate analysis showed the following factors as associated with the polymorphism: higher cigarette consumption, being a woman, and not having abdominal obesity. The AUC was 0.706. An association was found between increased cigarette consumption over the years and the presence of the C allele of the rs1414334 polymorphism in the HTR2C gene.

Multiple ECG Fiducial Points-Based Random Binary Sequence Generation for Securing Wireless Body Area Networks.

PubMed

Zheng, Guanglou; Fang, Gengfa; Shankaran, Rajan; Orgun, Mehmet A; Zhou, Jie; Qiao, Li; Saleem, Kashif

2017-05-01

Generating random binary sequences (BSes) is a fundamental requirement in cryptography. A BS is a sequence of N bits, and each bit has a value of 0 or 1. For securing sensors within wireless body area networks (WBANs), electrocardiogram (ECG)-based BS generation methods have been widely investigated in which interpulse intervals (IPIs) from each heartbeat cycle are processed to produce BSes. Using these IPI-based methods to generate a 128-bit BS in real time normally takes around half a minute. In order to improve the time efficiency of such methods, this paper presents an ECG multiple fiducial-points based binary sequence generation (MFBSG) algorithm. The technique of discrete wavelet transforms is employed to detect arrival time of these fiducial points, such as P, Q, R, S, and T peaks. Time intervals between them, including RR, RQ, RS, RP, and RT intervals, are then calculated based on this arrival time, and are used as ECG features to generate random BSes with low latency. According to our analysis on real ECG data, these ECG feature values exhibit the property of randomness and, thus, can be utilized to generate random BSes. Compared with the schemes that solely rely on IPIs to generate BSes, this MFBSG algorithm uses five feature values from one heart beat cycle, and can be up to five times faster than the solely IPI-based methods. So, it achieves a design goal of low latency. According to our analysis, the complexity of the algorithm is comparable to that of fast Fourier transforms. These randomly generated ECG BSes can be used as security keys for encryption or authentication in a WBAN system.

Connected Vehicle Pilot Deployment Program phase 1 : System Requirements Specification (SyRS) : Tampa (THEA) : final report.

DOT National Transportation Integrated Search

2016-08-01

This document describes the System Requirements Specification (SyRS) for the Tampa Hillsborough Expressway Authority (THEA) Connected Vehicle (CV) Pilot Deployment. This SyRS describes the current system requirements derived from the user needs, Conc...

Effects of a Self-Exercise Program on Activities of Daily Living in Patients After Acute Stroke: A Propensity Score Analysis Based on the Japan Association of Rehabilitation Database.

PubMed

Shiraishi, Nariaki; Suzuki, Yusuke; Matsumoto, Daisuke; Jeong, Seungwon; Sugiyama, Motoya; Kondo, Katsunori

2017-03-01

To investigate whether self-exercise programs for patients after stroke contribute to improved activities of daily living (ADL) at hospital discharge. Retrospective, observational, propensity score (PS)-matched case-control study. General hospitals. Participants included patients after stroke (N=1560) hospitalized between January 3, 2006, and December 26, 2012, satisfying the following criteria: (1) data on age, sex, duration from stroke to hospital admission, length of stay, FIM score, modified Rankin Scale (mRS) score, Glasgow Coma Scale score, Japan Stroke Scale score, and self-exercise program participation were available; and (2) admitted within 7 days after stroke onset, length of stay was between 7 and 60 days, prestroke mRS score was ≤2, and not discharged because of FIM or mRS exacerbation. A total of 780 PS-matched pairs were selected for each of the self-exercise program and no-self-exercise program groups. Self-exercise program participation. At discharge, FIM motor score, FIM cognitive score, FIM motor score gain (discharge value - admission value), FIM motor score gain rate (gain/length of stay), a binary variable divided by the median FIM motor score gain rate (high efficiency or no-high efficiency), and mRS score. Patients were classified into a self-exercise program (n=780) or a no-self-exercise program (n=780) group. After matching, there were no significant between-group differences, except motor system variables. The receiver operating characteristic curve for PS had an area under the curve value of .71 with a 95% confidence interval of .68 to .73, and the model was believed to have a relatively favorable fit. A logistic regression analysis of PS-matched pairs suggested that the self-exercise program was effective, with an overall odds ratio for ADL (high efficiency or no-high efficiency) of 2.2 (95% confidence ratio, 1.75-2.70). SEPs may contribute to improving ADL. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Remote sensing science for the Nineties; Proceedings of IGARSS '90 - 10th Annual International Geoscience and Remote Sensing Symposium, University of Maryland, College Park, May 20-24, 1990. Vols. 1, 2, & 3

NASA Technical Reports Server (NTRS)

1990-01-01

Various papers on remote sensing (RS) for the nineties are presented. The general topics addressed include: subsurface methods, radar scattering, oceanography, microwave models, atmospheric correction, passive microwave systems, RS in tropical forests, moderate resolution land analysis, SAR geometry and SNR improvement, image analysis, inversion and signal processing for geoscience, surface scattering, rain measurements, sensor calibration, wind measurements, terrestrial ecology, agriculture, geometric registration, subsurface sediment geology, radar modulation mechanisms, radar ocean scattering, SAR calibration, airborne radar systems, water vapor retrieval, forest ecosystem dynamics, land analysis, multisensor data fusion. Also considered are: geologic RS, RS sensor optical measurements, RS of snow, temperature retrieval, vegetation structure, global change, artificial intelligence, SAR processing techniques, geologic RS field experiment, stochastic modeling, topography and Digital Elevation model, SAR ocean waves, spaceborne lidar and optical, sea ice field measurements, millimeter waves, advanced spectroscopy, spatial analysis and data compression, SAR polarimetry techniques. Also discussed are: plant canopy modeling, optical RS techniques, optical and IR oceanography, soil moisture, sea ice back scattering, lightning cloud measurements, spatial textural analysis, SAR systems and techniques, active microwave sensing, lidar and optical, radar scatterometry, RS of estuaries, vegetation modeling, RS systems, EOS/SAR Alaska, applications for developing countries, SAR speckle and texture.

The Ruinous Influence of Close Binary Companions on Planetary Systems

NASA Astrophysics Data System (ADS)

Kraus, Adam L.; Ireland, Michael; Mann, Andrew; Huber, Daniel; Dupuy, Trent J.

2017-01-01

The majority of solar-type stars are found in binary systems, and the dynamical influence of binary companions is expected to profoundly influence planetary systems. However, the difficulty of identifying planets in binary systems has left the magnitude of this effect uncertain; despite numerous theoretical hurdles to their formation and survival, at least some binary systems clearly host planets. We present high-resolution imaging of nearly 500 Kepler Objects of Interest (KOIs) obtained using adaptive-optics imaging and nonredundant aperture-mask interferometry on the Keck II telescope. We super-resolve some binary systems to projected separations of under 5 AU, showing that planets might form in these dynamically active environments. However, the full distribution of projected separations for our planet-host sample more broadly reveals a deep paucity of binary companions at solar-system scales. When the binary population is parametrized with a semimajor axis cutoff a cut and a suppression factor inside that cutoff S bin, we find with correlated uncertainties that inside acut = 47 +59/-23 AU, the planet occurrence rate in binary systems is only Sbin = 0.34 +0.14/-0.15 times that of wider binaries or single stars. Our results demonstrate that a fifth of all solar-type stars in the Milky Way are disallowed from hosting planetary systems due to the influence of a binary companion.

The Ruinous Influence of Close Binary Companions on Planetary Systems

NASA Astrophysics Data System (ADS)

Kraus, Adam L.; Ireland, Michael; Mann, Andrew; Huber, Daniel; Dupuy, Trent J.

2017-06-01

The majority of solar-type stars are found in binary systems, and the dynamical influence of binary companions is expected to profoundly influence planetary systems. However, the difficulty of identifying planets in binary systems has left the magnitude of this effect uncertain; despite numerous theoretical hurdles to their formation and survival, at least some binary systems clearly host planets. We present high-resolution imaging of nearly 500 Kepler Objects of Interest (KOIs) obtained using adaptive-optics imaging and nonredundant aperture-mask interferometry on the Keck II telescope. We super-resolve some binary systems to projected separations of under 5 AU, showing that planets might form in these dynamically active environments. However, the full distribution of projected separations for our planet-host sample more broadly reveals a deep paucity of binary companions at solar-system scales. When the binary population is parametrized with a semimajor axis cutoff a cut and a suppression factor inside that cutoff S bin, we find with correlated uncertainties that inside acut = 47 +59/-23 AU, the planet occurrence rate in binary systems is only Sbin = 0.34+0.14/-0.15 times that of wider binaries or single stars. Our results demonstrate that a fifth of all solar-type stars in the Milky Way are disallowed from hosting planetary systems due to the influence of a binary companion.

Microarray-based comparison of three amplification methods for nanogram amounts of total RNA

PubMed Central

Singh, Ruchira; Maganti, Rajanikanth J.; Jabba, Sairam V.; Wang, Martin; Deng, Glenn; Heath, Joe Don; Kurn, Nurith; Wangemann, Philine

2007-01-01

Gene expression profiling using microarrays requires microgram amounts of RNA, which limits its direct application for the study of nanogram RNA samples obtained using microdissection, laser capture microscopy, or needle biopsy. A novel system based on Ribo-SPIA technology (RS, Ovation-Biotin amplification and labeling system) was recently introduced. The utility of the RS system, an optimized prototype system for picogram RNA samples (pRS), and two T7-based systems involving one or two rounds of amplification (OneRA, Standard Protocol, or TwoRA, Small Sample Prototcol, version II) were evaluated in the present study. Mouse kidney (MK) and mouse universal reference (MUR) RNA samples, 0.3 ng to 10 μg, were analyzed using high-density Affymetrix Mouse Genome 430 2.0 GeneChip arrays. Call concordance between replicates, correlations of signal intensity, signal intensity ratios, and minimal fold increase necessary for significance were determined. All systems amplified partially overlapping sets of genes with similar signal intensity correlations. pRS amplified the highest number of genes from 10-ng RNA samples. We detected 24 of 26 genes verified by RT-PCR in samples prepared using pRS. TwoRA yielded somewhat higher call concordances than did RS and pRS (91.8% vs. 89.3% and 88.1%, respectively). Although all target preparation methods were suitable, pRS amplified the highest number of targets and was found to be suitable for amplification of as little as 0.3 ng of total RNA. In addition, RS and pRS were faster and simpler to use than the T7-based methods and resulted in the generation of cDNA, which is more stable than cRNA. PMID:15613496

Effect of volatile compounds produced by Ralstonia solanacearum on plant growth promoting and systemic resistance inducing potential of Bacillus volatiles.

PubMed

Tahir, Hafiz Abdul Samad; Gu, Qin; Wu, Huijun; Raza, Waseem; Safdar, Asma; Huang, Ziyang; Rajer, Faheem Uddin; Gao, Xuewen

2017-08-02

Microbial volatiles play an expedient role in the agricultural ecological system by enhancing plant growth and inducing systemic resistance against plant pathogens, without causing hazardous effects on the environment. To explore the effects of VOCs of Ralstonia solanacearum TBBS1 (Rs) on tobacco plant growth and on plant growth promoting efficiency of VOCs produced by Bacillus subtilis SYST2, experiments were conducted both in vitro and in planta. The VOCs produced by SYST2 significantly enhanced the plant growth and induced the systemic resistance (ISR) against wilt pathogen Rs in all experiments. The SYST2-VOCs significantly increased PPO and PAL activity and over-expressed the genes relating to expansin, wilt resistance, and plant defense while repressed the genes relating to ethylene production. More interestingly, VOCs produced by pathogen, Rs had no significant effect on plant growth; however, Rs-VOCs decreased the growth promoting potential of SYST2-VOCs when plants were exposed to VOCs produced by both SYST2 and Rs. The co-culture of SYST2 and Rs revealed that they inhibited the growth of each other; however, the inhibition of Rs by SYST2-VOCs appeared to be greater than that of SYST2 by Rs-VOCs. Our findings provide new insights regarding the interaction among SYST2-VOCs, Rs-VOCs and plant, resulting in growth promotion and induced systemic resistance against the bacterial wilt pathogen Rs. This is the first report of the effect of VOCs produced by pathogenic microorganism on plant growth and on plant growth-promoting and systemic resistance-inducing potential of PGPR strain SYST2.

The disruption of multiplanet systems through resonance with a binary orbit.

PubMed

Touma, Jihad R; Sridhar, S

2015-08-27

Most exoplanetary systems in binary stars are of S-type, and consist of one or more planets orbiting a primary star with a wide binary stellar companion. Planetary eccentricities and mutual inclinations can be large, perhaps forced gravitationally by the binary companion. Earlier work on single planet systems appealed to the Kozai-Lidov instability wherein a sufficiently inclined binary orbit excites large-amplitude oscillations in the planet's eccentricity and inclination. The instability, however, can be quenched by many agents that induce fast orbital precession, including mutual gravitational forces in a multiplanet system. Here we report that orbital precession, which inhibits Kozai-Lidov cycling in a multiplanet system, can become fast enough to resonate with the orbital motion of a distant binary companion. Resonant binary forcing results in dramatic outcomes ranging from the excitation of large planetary eccentricities and mutual inclinations to total disruption. Processes such as planetary migration can bring an initially non-resonant system into resonance. As it does not require special physical or initial conditions, binary resonant driving is generic and may have altered the architecture of many multiplanet systems. It can also weaken the multiplanet occurrence rate in wide binaries, and affect planet formation in close binaries.

RS/1 in the Clinical Environment

PubMed Central

Kush, Thomas

1980-01-01

This paper describes the design of RS/1,™ the Research System, and its use in clinical patient studies. RS/1 is an interactive computer software system developed by the Medical Systems Group at BBN. Investigators and technicians who have never before used computers can learn RS/1 with a few hours of training. It uses familiar and intuitive concepts for data handling and data analysis, such as the “automated notebook” format of data storage, the direct use of graphs in curve-fitting, and a simple command language. Its versatility has made RS/1 useful in clinical research contexts, especially for studies involving patient care data.

Terrestrial Planet Formation in Binary Star Systems

NASA Technical Reports Server (NTRS)

Lissauer, Jack J.; Quintana, Elisa V.; Chambers, John; Duncan, Martin J.; Adams, Fred

2003-01-01

Most stars reside in multiple star systems; however, virtually all models of planetary growth have assumed an isolated single star. Numerical simulations of the collapse of molecular cloud cores to form binary stars suggest that disks will form within such systems. Observations indirectly suggest disk material around one or both components within young binary star systems. If planets form at the right places within such circumstellar disks, they can remain in stable orbits within the binary star systems for eons. We are simulating the late stages of growth of terrestrial planets within binary star systems, using a new, ultrafast, symplectic integrator that we have developed for this purpose. We show that the late stages of terrestrial planet formation can indeed take place in a wide variety of binary systems and we have begun to delineate the range of parameter space for which this statement is true. Results of our initial simulations of planetary growth around each star in the alpha Centauri system and other 'wide' binary systems, as well as around both stars in very close binary systems, will be presented.

Tryptophanyl-tRNA synthetase mediates high-affinity tryptophan uptake into human cells.

PubMed

Miyanokoshi, Miki; Yokosawa, Takumi; Wakasugi, Keisuke

2018-06-01

The tryptophan (Trp) transport system has a high affinity and selectivity toward Trp, and has been reported to exist in both human and mouse macrophages. Although this system is highly expressed in interferon-γ (IFN-γ)-treated cells and indoleamine 2,3-dioxygenase 1 (IDO1)-expressing cells, its identity remains incompletely understood. Tryptophanyl-tRNA synthetase (TrpRS) is also highly expressed in IFN-γ-treated cells and also has high affinity and selectivity for Trp. Here, we investigated the effects of human TrpRS expression on Trp uptake into IFN-γ-treated human THP-1 monocytes or HeLa cells. Inhibition of human TrpRS expression by TrpRS-specific siRNAs decreased and overexpression of TrpRS increased Trp uptake into the cells. Of note, the TrpRS-mediated uptake system had more than hundred-fold higher affinity for Trp than the known System L amino acid transporter, promoted uptake of low Trp concentrations, and had very high Trp selectivity. Moreover, site-directed mutagenesis experiments indicated that Trp- and ATP-binding sites, but not tRNA-binding sites, in TrpRS are essential for TrpRS-mediated Trp uptake into the human cells. We further demonstrate that the addition of purified TrpRS to cell culture medium increases Trp uptake into cells. Taken together, our results reveal that TrpRS plays an important role in high-affinity Trp uptake into human cells. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Genetic variants in the vitamin D pathway and breast cancer disease-free survival

PubMed Central

Brewster, Abenaa M.

2013-01-01

Epidemiological studies have investigated the association between vitamin D pathway genes and breast cancer risk; however, little is known about the association between vitamin D pathway genes and breast cancer prognosis. In a retrospective cohort of 1029 patients with early-stage breast cancer, we analyzed the association between 106 tagging single nucleotide polymorphisms (SNPs) in eight vitamin D pathway genes and breast cancer disease-free survival (DFS) using Cox regression analysis adjusted for known prognostic variables. Using a false discovery rate of 10%, six intronic SNPs were significantly associated with poorer DFS: retinoid-X receptor alpha (RXRA) SNPs (rs881658, rs11185659, rs10881583, rs881657 and rs7864987) and plasminogen activator and urokinase receptor (PLAUR) SNP (rs4251864). Treatment received (no systemic therapy, hormone therapy alone or chemotherapy) was an effect modifier of the RXRA SNPs association with DFS (P < 0.05); therefore, we stratified further analysis by treatment group. Among patients who did not receive systemic therapy, RXRA SNP [rs10881583 (P = 0.02)] was associated with poorer DFS, and among patients who received chemotherapy, RXRA SNPs (rs881658, rs11185659, rs10881583, rs881657 and rs7864987) were associated with poorer DFS (P < 0.001 for all SNPs). However, RXRA SNPs: rs10881583 (P < 0.001) and rs881657 (P = 0.02) were associated with improved DFS in patients treated with hormone therapy alone. Our results suggest that SNPs in the RXRA and PLAUR genes in the vitamin D pathway may contribute to breast cancer DFS. In particular, SNPs in RXRA may predict for poorer or improved DFS in patients, according to type of systemic treatment received. If validated, these markers could be used for risk stratification of breast cancer patients. PMID:23180655

Single-Nucleotide Polymorphisms of FAS and FASL Genes and Risk of Idiopathic Aplastic Anemia.

PubMed

Rehman, Sadia; Saba, Nusrat; Naz, Madiha; Ahmed, Parvez; Munir, Saeeda; Sajjad, Sumaira; Tabassum, Sobia; Naseem, Lubna

2018-04-03

FAS/FASL signaling system plays a vital role in the regulation of apoptosis, envisaged as a death process required for immune surveillance to prevent autoimmunity and tumorigenesis along with several other biological activities. Several single-nucleotide polymorphisms (SNPs) of FAS/FASL system can result in aberrant apoptosis, which can cause different cancers and autoimmune diseases. Aplastic anemia (AA) is an autoimmune dysfunction characterized by peripheral blood pancytopenia associated with hypoplasia of bone marrow. The aim of this study was to screen Pakistani AA patients and controls for two Fas SNPs rs2234767 and rs1800682 and two FASLG SNPs rs763110 and rs5030772. Genotyping of 392 DNA samples was done by Tetra-ARMS polymerase chain reaction. Genotypic frequencies of Fas rs1800682 and FASLG rs5030772 showed significance difference in their distribution in both controls and patients, while Fas rs2234767 and FASLG rs763110 SNPs had no such difference. Carriers of rs1800682 AG+GG had a very odd ratio of 4.63, with 95% confidence interval (CI) of 3.01-7.11, while individuals with FASLG rs5030772 AG+GG were more common in controls than patients with OR 0.53 and 95% CI of 0.34-0.83. Cumulative effects of these SNPs were analyzed, and they showed almost similar trends; however, Fas rs2234767 and FASLG rs763110 genotypes in combination with Fas rs1800682 and FASLG rs5030772 demonstrated significant association. This study provided information that endorsed the involvement of FAS/FASL system SNPs in the pathogenesis of AA; further studies should be designed to understand the exact role of SNPs that can help in early diagnosis and treatment.

Equilibrium points and associated periodic orbits in the gravity of binary asteroid systems: (66391) 1999 KW4 as an example

NASA Astrophysics Data System (ADS)

Shi, Yu; Wang, Yue; Xu, Shijie

2018-04-01

The motion of a massless particle in the gravity of a binary asteroid system, referred as the restricted full three-body problem (RF3BP), is fundamental, not only for the evolution of the binary system, but also for the design of relevant space missions. In this paper, equilibrium points and associated periodic orbit families in the gravity of a binary system are investigated, with the binary (66391) 1999 KW4 as an example. The polyhedron shape model is used to describe irregular shapes and corresponding gravity fields of the primary and secondary of (66391) 1999 KW4, which is more accurate than the ellipsoid shape model in previous studies and provides a high-fidelity representation of the gravitational environment. Both of the synchronous and non-synchronous states of the binary system are considered. For the synchronous binary system, the equilibrium points and their stability are determined, and periodic orbit families emanating from each equilibrium point are generated by using the shooting (multiple shooting) method and the homotopy method, where the homotopy function connects the circular restricted three-body problem and RF3BP. In the non-synchronous binary system, trajectories of equivalent equilibrium points are calculated, and the associated periodic orbits are obtained by using the homotopy method, where the homotopy function connects the synchronous and non-synchronous systems. Although only the binary (66391) 1999 KW4 is considered, our methods will also be well applicable to other binary systems with polyhedron shape data. Our results on equilibrium points and associated periodic orbits provide general insights into the dynamical environment and orbital behaviors in proximity of small binary asteroids and enable the trajectory design and mission operations in future binary system explorations.

Box codes of lengths 48 and 72

NASA Technical Reports Server (NTRS)

Solomon, G.; Jin, Y.

1993-01-01

A self-dual code length 48, dimension 24, with Hamming distance essentially equal to 12 is constructed here. There are only six code words of weight eight. All the other code words have weights that are multiples of four and have a minimum weight equal to 12. This code may be encoded systematically and arises from a strict binary representation of the (8,4;5) Reed-Solomon (RS) code over GF (64). The code may be considered as six interrelated (8,7;2) codes. The Mattson-Solomon representation of the cyclic decomposition of these codes and their parity sums are used to detect an odd number of errors in any of the six codes. These may then be used in a correction algorithm for hard or soft decision decoding. A (72,36;15) box code was constructed from a (63,35;8) cyclic code. The theoretical justification is presented herein. A second (72,36;15) code is constructed from an inner (63,27;16) Bose Chaudhuri Hocquenghem (BCH) code and expanded to length 72 using box code algorithms for extension. This code was simulated and verified to have a minimum distance of 15 with even weight words congruent to zero modulo four. The decoding for hard and soft decision is still more complex than the first code constructed above. Finally, an (8,4;5) RS code over GF (512) in the binary representation of the (72,36;15) box code gives rise to a (72,36;16*) code with nine words of weight eight, and all the rest have weights greater than or equal to 16.

The Impact of Binary Companions on Planetary Systems

NASA Astrophysics Data System (ADS)

Kraus, Adam L.; Ireland, Michael; Dupuy, Trent; Mann, Andrew; Huber, Daniel

2018-01-01

The majority of solar-type stars are found in binary systems, and the dynamical influence of binary companions is expected to profoundly influence planetary systems. However, the difficulty of identifying planets in binary systems has left the magnitude of this effect uncertain; despite numerous theoretical hurdles to their formation and survival, at least some binary systems clearly host planets. We present high-resolution imaging of nearly 500 Kepler Objects of Interest (KOIs) obtained using adaptive-optics imaging and nonredundant aperture-mask interferometry on the Keck II telescope. We super-resolve some binary systems to projected separations of under 5 AU, showing that planets might form in these dynamically active environments. However, the full distribution of projected separations for our planet-host sample more broadly reveals a deep paucity of binary companions at solar-system scales. Our results demonstrate that a fifth of all solar-type stars in the Milky Way are disallowed from hosting planetary systems due to the influence of a binary companion. We now update these results with multi-epoch imaging to reject non-comoving background stars and securely identify even the least massive stellar companions, as well as tracing out the orbital motion of stellar companions. These results are beginning to reveal not just the fraction of binaries that do not host planets, but also potential explanations for planet survival even in some very close, dynamically active binary systems.

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

PubMed

Stairs, Ingrid H

2004-04-23

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

Performance of concatenated Reed-Solomon/Viterbi channel coding

NASA Technical Reports Server (NTRS)

Divsalar, D.; Yuen, J. H.

1982-01-01

The concatenated Reed-Solomon (RS)/Viterbi coding system is reviewed. The performance of the system is analyzed and results are derived with a new simple approach. A functional model for the input RS symbol error probability is presented. Based on this new functional model, we compute the performance of a concatenated system in terms of RS word error probability, output RS symbol error probability, bit error probability due to decoding failure, and bit error probability due to decoding error. Finally we analyze the effects of the noisy carrier reference and the slow fading on the system performance.

Genotypes and Haplotypes of the Estrogen Receptor α Gene (ESR1) Are Associated With Female-to-Male Gender Dysphoria.

PubMed

Cortés-Cortés, Joselyn; Fernández, Rosa; Teijeiro, Nerea; Gómez-Gil, Esther; Esteva, Isabel; Almaraz, Mari Cruz; Guillamón, Antonio; Pásaro, Eduardo

2017-03-01

Gender dysphoria, a marked incongruence between one's experienced gender and biological sex, is commonly believed to arise from discrepant cerebral and genital sexual differentiation. With the discovery that estrogen receptor β is associated with female-to-male (FtM) but not with male-to-female (MtF) gender dysphoria, and given estrogen receptor α involvement in central nervous system masculinization, it was hypothesized that estrogen receptor α, encoded by the ESR1 gene, also might be implicated. To investigate whether ESR1 polymorphisms (TA)n-rs3138774, PvuII-rs2234693, and XbaI-rs9340799 and their haplotypes are associated with gender dysphoria in adults. Molecular analysis was performed in peripheral blood samples from 183 FtM subjects, 184 MtF subjects, and 394 sex- and ethnically-matched controls. Genotype and haplotype analyses of the (TA)n-rs3138774, PvuII-rs2234693, and XbaI-rs9340799 polymorphisms. Allele and genotype frequencies for the polymorphism XbaI were statistically significant only in FtM vs control XX subjects (P = .021 and P = .020). In XX individuals, the A/G genotype was associated with a low risk of gender dysphoria (odds ratio [OR] = 0.34; 95% CI = 0.16-0.74; P = .011); in XY individuals, the A/A genotype implied a low risk of gender dysphoria (OR = 0.39; 95% CI = 0.17-0.89; P = .008). Binary logistic regression showed partial effects for all three polymorphisms in FtM but not in MtF subjects. The three polymorphisms were in linkage disequilibrium: a small number of TA repeats was linked to the presence of PvuII and XbaI restriction sites (haplotype S-T-A), and a large number of TA repeats was linked to the absence of these restriction sites (haplotype L-C-G). In XX individuals, the presence of haplotype L-C-G carried a low risk of gender dysphoria (OR = 0.66; 95% CI = 0.44-0.99; P = .046), whereas the presence of haplotype L-C-A carried a high susceptibility to gender dysphoria (OR = 3.96; 95% CI = 1.04-15.02; P = .044). Global haplotype was associated with FtM gender dysphoria (P = .017) but not with MtF gender dysphoria. XbaI-rs9340799 is involved in FtM gender dysphoria in adults. Our findings suggest different genetic programs for gender dysphoria in men and women. Cortés-Cortés J, Fernández R, Teijeiro N, et al. Genotypes and Haplotypes of the Estrogen Receptor α Gene (ESR1) Are Associated With Female-to-Male Gender Dysphoria. J Sex Med 2017;14:464-472. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

[Genetic polymorphisms of ARL15 and HLA-DMA are associated with rheumatoid arthritis in Han population from northwest China].

PubMed

Wang, Jiao; Qi, Xiaoming; Zhang, Xiaozhen; Yan, Wen; You, Chongge

2017-12-01

Objective To establish the methods for detecting single nucleotide polymorphisms (SNPs) of ADP-ribosylation factor-like GTPase 15 (ARL15), major histocompatibility complex class II-DM alpha (HLA-DMA ) and nuclear factor kappa B subunit 2 (NFKB2) genes using high resolution melting (HRM) technology, and to explore the association of those SNPs with the susceptibility of rheumatoid arthritis (RA) in northwestern Han Chinese population. Methods The PCR-HRM detection system for four SNPs (rs255758, rs1063478, rs397514331 and rs397514332) was established for genotyping, and gene sequencing was performed to validate the genotyping ability of the system. 588 RA cases and 200 controls were enrolled in a case-control study to analyze the associations of ARL15 and HLA-DMA gene polymorphisms with RA risk. Results The direct sequencing validated that the established PCR-HRM detection system could be used for genotyping clinical samples correctly. The mutated genotype of rs397514331 and rs397514332 from NFKB2 gene are not found in this study. The genotype frequencies of rs255758 and rs1063478 had statistical difference between the cases and controls, but no statistical difference in allelic frequencies. Under the dominant model (AA vs AC/CC), the AA genotype of rs255758 decreases the RA risk (OR=0.666, 95%CI=0.478-0.927, P=0.016). Conclusion The method of PCR-HRM we established can be applied to the routine detection of rs255758, rs1063478, rs397514331 and rs397514332. The ARL15 and HLA-DMA gene polymorphisms are associated with RA risk in Northwestern Han Chinese population.

Implication of IL-2/IL-21 region in systemic sclerosis genetic susceptibility

PubMed Central

Diaz-Gallo, Lina-Marcela; Simeon, Carmen P; Broen, Jasper C; Ortego-Centeno, Norberto; Beretta, Lorenzo; Vonk, Madelon C; Carreira, Patricia E; Vargas, Sofia; Román-Ivorra, José Andrés; González-Gay, Miguel A; Tolosa, Carlos; López-Longo, Francisco Javier; Espinosa, Gerard; Vicente, Esther F; Hesselstrand, Roger; Riemekasten, Gabriela; Witte, Torsten; Distler, Jörg H W; Voskuyl, Alexandre E; Schuerwegh, Annemie J; Shiels, Paul G; Nordin, Annika; Padyukov, Leonid; Hoffmann-Vold, Anna-Maria; Scorza, Raffaella; Lunardi, Claudio; Airo, Paolo; van Laar, Jacob M; Hunzelmann, Nicolas; Gathof, Birgit S; Kreuter, Alexander; Herrick, Ariane; Worthington, Jane; Denton, Christopher P; Zhou, Xiaodong; Arnett, Frank C; Fonseca, Carmen; Koeleman, Bobby PC; Assasi, Shervin; Radstake, Timothy R D J; Mayes, Maureen D; Martín, Javier

2013-01-01

Objective The interleukin 2 (IL-2) and interleukin 21 (IL-21) locus at chromosome 4q27 has been associated with several autoimmune diseases, and both genes are related to immune system functions. The aim of this study was to evaluate the role of the IL-2/IL-21 locus in systemic sclerosis (SSc). Patients and methods The case control study included 4493 SSc Caucasian patients and 5856 healthy controls from eight Caucasian populations (Spain, Germany, The Netherlands, USA, Italy, Sweden, UK and Norway). Four single nucleotide polymorphisms (rs2069762, rs6822844, rs6835457 and rs907715) were genotyped using TaqMan allelic discrimination assays. Results We observed evidence of association of the rs6822844 and rs907715 variants with global SSc (pc=6.6E-4 and pc=7.2E-3, respectively). Similar statistically significant associations were observed for the limited cutaneous form of the disease. The conditional regression analysis suggested that the most likely genetic variation responsible for the association was the rs6822844 polymorphism. Consistently, the rs2069762A-rs6822844T-rs6835457G-rs907715T allelic combination showed evidence of association with SSc and limited cutaneous SSc subtype (pc=1.7E-03 and pc=8E-4, respectively). Conclusions These results suggested that the IL-2/IL-21 locus influences the genetic susceptibility to SSc. Moreover, this study provided further support for the IL-2/IL-21 locus as a common genetic factor in autoimmune diseases. PMID:23172754

Connected Vehicle Pilot Deployment Program Phase 1, System Requirements Specification (SyRS) – New York City.

DOT National Transportation Integrated Search

2016-07-28

This document describes the System Requirements Specification (SyRS) for the New York City Department of Transportation (NYC) Connected Vehicle Pilot Deployment (CVPD) Project. This SyRS describes the results of the definition of need, the operationa...

Activity in X-ray-selected late-type stars

NASA Technical Reports Server (NTRS)

Takalo, Leo O.; Nousek, J. A.

1988-01-01

A spectroscopic study has been conducted of nine X-ray bright late-type stars selected from two Einstein X-ray surveys: the Columbia Astrophysical Laboratory Survey (five stars) and the CFA Medium Sensitivity Survey (MSS; four stars). Spectral classes were determined and radial and V sin(i) velocities were measured for the stars. Four of the Columbia Survey stars were found to be new RS CVn-type binaries. The fifth Columbia survey star was found to be an active G dwarf star without evidence for binarity. None of the four MSS stars were found to be either binaries or optically active stars. Activity in these stars was assessed by measuring the excess emission in H-alpha and the Ca II IRT (8498, 8542) lines in comparison with inactive stars of similar spectral types. A correlation was found between X-ray luminosity and V sin(i) and H-alpha line excess. The measured excess line emission in H-alpha was also correlated with V sin(i) but not with the IRT line excess.

The Spotted Active Binary UX Arietis

NASA Astrophysics Data System (ADS)

Hummel, Christian

2018-04-01

UX Arietis is one of the most active members of the RS CVn class of binaries in which spin-up of a sub-giant/giant star by a close companion led to the creation of magnetic fields which in turn are responsible for the radio and X-ray flares of UX Ariestis as well as its photometric variability. We observed this binary with the MIRC beam combiner at the CHARA array and made images of a single large spot rotating in and out of view over a month in 2012. A precise orbit was derived using the Wilson-Devinney code to account for the effect of the spot on the measured visibilities. Archival and new radial velocities taken at the NOT were also corrected for spot activity and allowed us to determine precise stellar masses and luminosities for the components. Consistency with the predicted locations in the HR-diagram is achieved after a careful analysis of the effect of spots. The orbit can be used to establish the relative locations of the stellar components at times when radio observations by Ros and Massi (2007) with the VLBA detected two radio components moving around each other. We tentatively conclude that radio emission in UX Arietis flows along magnetic flux tubes between the stars.

R144: a very massive binary likely ejected from R136 through a binary-binary encounter

NASA Astrophysics Data System (ADS)

Oh, Seungkyung; Kroupa, Pavel; Banerjee, Sambaran

2014-02-01

R144 is a recently confirmed very massive, spectroscopic binary which appears isolated from the core of the massive young star cluster R136. The dynamical ejection hypothesis as an origin for its location is claimed improbable by Sana et al. due to its binary nature and high mass. We demonstrate here by means of direct N-body calculations that a very massive binary system can be readily dynamically ejected from an R136-like cluster, through a close encounter with a very massive system. One out of four N-body cluster models produces a dynamically ejected very massive binary system with a mass comparable to R144. The system has a system mass of ≈355 M⊙ and is located at 36.8 pc from the centre of its parent cluster, moving away from the cluster with a velocity of 57 km s-1 at 2 Myr as a result of a binary-binary interaction. This implies that R144 could have been ejected from R136 through a strong encounter with another massive binary or single star. In addition, we discuss all massive binaries and single stars which are ejected dynamically from their parent cluster in the N-body models.

The specificity of action knowledge in sensory and motor systems

PubMed Central

Watson, Christine E.; Cardillo, Eileen R.; Bromberger, Bianca; Chatterjee, Anjan

2014-01-01

Neuroimaging studies have found that sensorimotor systems are engaged when participants observe actions or comprehend action language. However, most of these studies have asked the binary question of whether action concepts are embodied or not, rather than whether sensory and motor areas of the brain contain graded amounts of information during putative action simulations. To address this question, we used repetition suppression (RS) functional magnetic resonance imaging to determine if functionally-localized motor movement and visual motion regions-of-interest (ROI) and two anatomical ROIs (inferior frontal gyrus, IFG; left posterior middle temporal gyrus, pMTG) were sensitive to changes in the exemplar (e.g., two different people “kicking”) or representational format (e.g., photograph or schematic drawing of someone “kicking”) within pairs of action images. We also investigated whether concrete versus more symbolic depictions of actions (i.e., photographs or schematic drawings) yielded different patterns of activation throughout the brain. We found that during a conceptual task, sensory and motor systems represent actions at different levels of specificity. While the visual motion ROI did not exhibit RS to different exemplars of the same action or to the same action depicted by different formats, the motor movement ROI did. These effects are consistent with “person-specific” action simulations: if the motor system is recruited for action understanding, it does so by activating one's own motor program for an action. We also observed significant repetition enhancement within the IFG ROI to different exemplars or formats of the same action, a result that may indicate additional cognitive processing on these trials. Finally, we found that the recruitment of posterior brain regions by action concepts depends on the format of the input: left lateral occipital cortex and right supramarginal gyrus responded more strongly to symbolic depictions of actions than concrete ones. PMID:24904506

TLR7/8/9 polymorphisms and their associations in systemic lupus erythematosus patients from southern Brazil.

PubMed

dos Santos, B P; Valverde, J V; Rohr, P; Monticielo, O A; Brenol, J C T; Xavier, R M; Chies, J A B

2012-03-01

Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease and can affect several organs and systems. It is characterized by high production of autoantibodies against nuclear compounds. TLR7/8/9 are responsible for nucleic acid recognition and they trigger proinflammatory responses through activation of NK-kappaB and Type I IFN production, making a bridge between the innate and the adaptative immune systems. We analyzed the frequency of TLR7 rs179008, TLR8 rs3764880, TLR9 rs5743836 and rs352140 in 370 patients with SLE and 415 healthy controls from southern Brazil. All analyses were conducted with regard to gender and ethnicity. Genotypic and allelic frequencies were different for TLR7 rs179008 (0.253 vs. 0.163, p = 0.020 and p = 0.003, OR for T allele: 1.74 CI 95% 1.12-2.70) and TLR9 rs5743836 (0.174 vs. 0.112, p = 0.045 and p = 0.017, OR for C allele: 1.59, CI 95% 0.99-2.57) between European-derived female groups. A higher frequency was observed for the presence of Anti-SSa/Ro for TRL9 rs5743836 C allele carriers (0.228 vs 0.126, Bonferroni corrected p = 0.06). No statistical differences were found for TLR9 haplotypic analyses. We suggest that TLR7 rs179008 and TLR9 rs5743836 can be considered SLE susceptibility factors for women of European descent in our population.

The Digestive System and Nutritional Considerations for Individuals with Rett Syndrome

PubMed Central

Lotan, Meir; Zysman, Lilit

2006-01-01

Rett syndrome (RS) is a neurodevelopmental syndrome of genetic origin that mainly affects females. Individuals diagnosed with RS exhibit a variety of functional difficulties that impair their quality of life. One of the affected systems is the digestive system, where 74% of persons with RS have abnormal functioning. The affected digestive system causes this population to present an array of problems, such as gastroesophageal reflux (GER), constipation, and malnutrition, leading to failure to thrive (FTT), which resolves in reduced functional ability. Due to the severe effects of the dysfunctional digestive system of individuals with RS, this article will describe the problems common to this population, as well as propose some clinical suggestions for intervention. . PMID:17195872

Gamma-Ray Burst Optical Afterglows with Two-component Jets: Polarization Evolution Revisited

NASA Astrophysics Data System (ADS)

Lan, Mi-Xiang; Wu, Xue-Feng; Dai, Zi-Gao

2018-06-01

Gamma-ray bursts have been widely argued to originate from binary compact object mergers or core collapse of massive stars. Jets from these systems may have two components: an inner, narrow sub-jet and an outer, wider sub-jet. Such a jet subsequently interacts with its ambient gas, leading to a reverse shock (RS) and a forward shock. The magnetic field in the narrow sub-jet is very likely to be mixed by an ordered component and a random component during the afterglow phase. In this paper, we calculate light curves and polarization evolution of optical afterglows with this mixed magnetic field in the RS region of the narrow sub-jet in a two-component jet model. The resultant light curve has two peaks: an early peak arising from the narrow sub-jet and a late-time rebrightening due to the wider sub-jet. We find the polarization degree (PD) evolution under such a mixed magnetic field confined in the shock plane is very similar to that under the purely ordered magnetic field condition. The two-dimensional “mixed” magnetic fields confined in the shock plane are essentially the ordered magnetic fields only with different configurations. The position angle (PA) of the two-component jet can change gradually or abruptly by 90°. In particular, an abrupt 90° change of the PA occurs when the PD changes from its decline phase to the rise phase.

A non-synonymous SNP in the NOS2 associated with septic shock in patients with sepsis in Chinese populations.

PubMed

Wang, Zhifu; Feng, Kai; Yue, Maoxing; Lu, Xiaoguang; Zheng, Qihan; Zhang, Hongxing; Zhai, Yun; Li, Peiyao; Yu, Lixia; Cai, Mi; Zhang, Xiumei; Kang, Xin; Shi, Weihai; Xia, Xia; Chen, Xi; Cao, Pengbo; Li, Yuanfeng; Chen, Huipeng; Ling, Yan; Li, Yuxia; He, Fuchu; Zhou, Gangqiao

2013-03-01

Sepsis represents a systemic inflammatory response to infection and its sequelae include severe sepsis, septic shock, multiple organ dysfunction syndrome (MODS) and death. Studies in mice and humans indicate that the inducible nitric oxide synthase (iNOS, NOS2) plays an important role in the development of sepsis and its sequelae. It was reported that several single nucleotide polymorphisms (SNPs) within NOS2 could influence the production or activity of NOS2. In this study, we assessed whether SNPs within NOS2 gene were associated with severity of sepsis in Chinese populations. A case-control study was conducted, which included 299 and 280 unrelated patients with sepsis recruited from Liaoning and Jiangsu provinces in China, respectively. Six SNPs within NOS2 were genotyped using Sequenom MassARRAY system. The associations between the SNPs and risk of sepsis complications were estimated by a binary logistic regression model adjusted for confounding factors. Functional assay was performed to assess the biological significance. The GA + AA genotype of a non-synonymous SNP in the exon 16 of NOS2 (rs2297518: G>A) was significantly associated with increased susceptibility to septic shock compared with GG genotype in Liaoning population (OR = 3.29, 95% CI = 1.40-7.72, P = 0.0047). This association was confirmed in the Jiangsu population (OR = 3.49, 95% CI = 1.57-7.79, P = 0.0019). Furthermore, the functional assay performed in the immortalized lymphocyte cell lines indicated that the at-risk GA genotype had a tendency of higher NOS2 activity than the GG genotype (P = 0.32). Our findings suggest that the NOS2 rs2297518 may play a role in mediating the susceptibility to septic shock in patients with sepsis in Chinese populations.

Improving geothermal power plants with a binary cycle

NASA Astrophysics Data System (ADS)

Tomarov, G. V.; Shipkov, A. A.; Sorokina, E. V.

2015-12-01

The recent development of binary geothermal technology is analyzed. General trends in the introduction of low-temperature geothermal sources are summarized. The use of single-phase low-temperature geothermal fluids in binary power plants proves possible and expedient. The benefits of power plants with a binary cycle in comparison with traditional systems are shown. The selection of the working fluid is considered, and the influence of the fluid's physicochemical properties on the design of the binary power plant is discussed. The design of binary power plants is based on the chemical composition and energy potential of the geothermal fluids and on the landscape and climatic conditions at the intended location. Experience in developing a prototype 2.5 MW Russian binary power unit at Pauzhetka geothermal power plant (Kamchatka) is outlined. Most binary systems are designed individually for a specific location. Means of improving the technology and equipment at binary geothermal power plants are identified. One option is the development of modular systems based on several binary systems that employ the heat from the working fluid at different temperatures.

Contact Binaries on Their Way Towards Merging

NASA Astrophysics Data System (ADS)

Gazeas, K.

2015-07-01

Contact binaries are the most frequently observed type of eclipsing star system. They are small, cool, low-mass binaries belonging to a relatively old stellar population. They follow certain empirical relationships that closely connect a number of physical parameters with each other, largely because of constraints coming from the Roche geometry. As a result, contact binaries provide an excellent test of stellar evolution, specifically for stellar merger scenarios. Observing campaigns by many authors have led to the cataloging of thousands of contact binaries and enabled statistical studies of many of their properties. A large number of contact binaries have been found to exhibit extraordinary behavior, requiring follow-up observations to study their peculiarities in detail. For example, a doubly-eclipsing quadruple system consisting of a contact binary and a detached binary is a highly constrained system offering an excellent laboratory to test evolutionary theories for binaries. A new observing project was initiated at the University of Athens in 2012 in order to investigate the possible lower limit for the orbital period of binary systems before coalescence, prior to merging.

Dynamics of rotationally fissioned asteroids: Source of observed small asteroid systems

NASA Astrophysics Data System (ADS)

Jacobson, Seth A.; Scheeres, Daniel J.

2011-07-01

We present a model of near-Earth asteroid (NEA) rotational fission and ensuing dynamics that describes the creation of synchronous binaries and all other observed NEA systems including: doubly synchronous binaries, high- e binaries, ternary systems, and contact binaries. Our model only presupposes the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect, "rubble pile" asteroid geophysics, and gravitational interactions. The YORP effect torques a "rubble pile" asteroid until the asteroid reaches its fission spin limit and the components enter orbit about each other (Scheeres, D.J. [2007]. Icarus 189, 370-385). Non-spherical gravitational potentials couple the spin states to the orbit state and chaotically drive the system towards the observed asteroid classes along two evolutionary tracks primarily distinguished by mass ratio. Related to this is a new binary process termed secondary fission - the secondary asteroid of the binary system is rotationally accelerated via gravitational torques until it fissions, thus creating a chaotic ternary system. The initially chaotic binary can be stabilized to create a synchronous binary by components of the fissioned secondary asteroid impacting the primary asteroid, solar gravitational perturbations, and mutual body tides. These results emphasize the importance of the initial component size distribution and configuration within the parent asteroid. NEAs may go through multiple binary cycles and many YORP-induced rotational fissions during their approximately 10 Myr lifetime in the inner Solar System. Rotational fission and the ensuing dynamics are responsible for all NEA systems including the most commonly observed synchronous binaries.

Association of IRF5 polymorphisms with susceptibility to macrophage activation syndrome in patients with juvenile idiopathic arthritis.

PubMed

Yanagimachi, Masakatsu; Naruto, Takuya; Miyamae, Takako; Hara, Takuma; Kikuchi, Masako; Hara, Ryoki; Imagawa, Tomoyuki; Mori, Masaaki; Sato, Hidenori; Goto, Hiroaki; Yokota, Shumpei

2011-04-01

Systemic-onset juvenile idiopathic arthritis (systemic JIA) and macrophage activation syndrome (MAS), the most devastating complication of systemic JIA, are characterized by abnormal levels of proinflammatory cytokines. Interferon regulatory factor 5 (IRF5) is a member of the IRF family of transcription factors, and acts as a master transcription factor in the activation of genes encoding proinflammatory cytokines. Polymorphisms in the IRF5 gene have been associated with susceptibility to autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis. Our aim was to assess associations of IRF5 gene polymorphisms with susceptibility to systemic JIA and MAS. Three IRF5 single-nucleotide polymorphisms (rs729302, rs2004640, and rs2280714) were genotyped using TaqMan assays in 81 patients with systemic JIA (33 with MAS, 48 without) and 190 controls. There were no associations of the IRF5 gene polymorphisms or haplotypes under study with susceptibility to systemic JIA. There was a significant association of the rs2004640 T allele with MAS susceptibility (OR 4.11; 95% CI 1.84, 9.16; p = 0.001). The IRF5 haplotype (rs729302 A, rs2004640 T, and rs2280714 T), which was reported as conferring an increased risk of SLE, was significantly associated with MAS susceptibility in patients with systemic JIA (OR 4.61; 95% CI 1.73, 12.3; p < 0.001). IRF5 gene polymorphism is a genetic factor influencing susceptibility to MAS in patients with systemic JIA, and IRF5 contributes to the pathogenesis of MAS in these patients.

Close binary systems among very low-mass stars and brown dwarfs

NASA Astrophysics Data System (ADS)

Jeffries, R. D.; Maxted, P. F. L.

2005-12-01

Using Monte Carlo simulations and published radial velocity surveys we have constrained the frequency and separation (a) distribution of very low-mass star (VLM) and brown dwarf (BD) binary systems. We find that simple Gaussian extensions of the observed wide binary distribution, with a peak at 4 AU and 0.6<\\sigma_{\\log(a/AU)}<1.0, correctly reproduce the observed number of close binary systems, implying a close (a<2.6 AU) binary frequency of 17-30 % and overall frequency of 32-45 %. N-body models of the dynamical decay of unstable protostellar multiple systems are excluded with high confidence because they do not produce enough close binary VLMs/BDs. The large number of close binaries and high overall binary frequency are also completely inconsistent with published smoothed particle hydrodynamical modelling and argue against a dynamical origin for VLMs/BDs.

Improved eye- and skin-color prediction based on 8 SNPs.

PubMed

Hart, Katie L; Kimura, Shey L; Mushailov, Vladimir; Budimlija, Zoran M; Prinz, Mechthild; Wurmbach, Elisa

2013-06-01

To improve the 7-plex system to predict eye and skin color by increasing precision and detailed phenotypic descriptions. Analysis of an eighth single nucleotide polymorphism (SNP), rs12896399 (SLC24A4), showed a statistically significant association with human eye color (P=0.007) but a rather poor strength of agreement (κ=0.063). This SNP was added to the 7-plex system (rs12913832 at HERC2, rs1545397 at OCA2, rs16891982 at SLC45A2, rs1426654 at SLC24A5, rs885479 at MC1R, rs6119471 at ASIP, and rs12203592 at IRF4). Further, the instruction guidelines on the interpretation of genotypes were changed to create a new 8-plex system. This was based on the analysis of an 803-sample training set of various populations. The newly developed 8-plex system can predict the eye colors brown, green, and blue, and skin colors light, not dark, and not light. It is superior to the 7-plex system with its additional ability to predict blue eye and light skin color. The 8-plex system was tested on an additional 212 samples, the test set. Analysis showed that the number of positive descriptions for eye colors as being brown, green, or blue increased significantly (P=6.98e-15, z-score: -7.786). The error rate for eye-color prediction was low, at approximately 5%, while the skin color prediction showed no error in the test set (1% in training set). We can conclude that the new 8-plex system for the prediction of eye and skin color substantially enhances its former version.

SIM Lite Detection of Habitable Planets in P-Type Binary-Planetary Systems

NASA Technical Reports Server (NTRS)

Pan, Xiaopei; Shao, Michael; Shaklan, Stuart; Goullioud, Renaud

2010-01-01

Close binary stars like spectroscopic binaries create a completely different environment than single stars for the evolution of a protoplanetary disk. Dynamical interactions between one star and protoplanets in such systems provide more challenges for theorists to model giant planet migration and formation of multiple planets. For habitable planets the majority of host stars are in binary star systems. So far only a small amount of Jupiter-size planets have been discovered in binary stars, whose minimum separations are 20 AU and the median value is about 1000 AU (because of difficulties in radial velocity measurements). The SIM Lite mission, a space-based astrometric observatory, has a unique capability to detect habitable planets in binary star systems. This work analyzed responses of the optical system to the field stop for companion stars and demonstrated that SIM Lite can observe exoplanets in visual binaries with small angular separations. In particular we investigated the issues for the search for terrestrial planets in P-type binary-planetary systems, where the planets move around both stars in a relatively distant orbit.

Genetic variation of the ghrelin signaling system in females with severe alcohol dependence.

PubMed

Landgren, Sara; Jerlhag, Elisabet; Hallman, Jarmila; Oreland, Lars; Lissner, Lauren; Strandhagen, Elisabeth; Thelle, Dag S; Zetterberg, Henrik; Blennow, Kaj; Engel, Jörgen A

2010-09-01

Central ghrelin signaling is required for the rewarding effects of alcohol in mice. Because ghrelin is implied in other addictive behaviors such as eating disorders and smoking, and because there is co-morbidity between these disorders and alcohol dependence, the ghrelin signaling system could be involved in mediating reward in general. Furthermore, in humans, single nucleotide polymorphisms (SNPs) and haplotypes of the pro-ghrelin gene (GHRL) and the ghrelin receptor gene (GHSR) have previously been associated with increased alcohol consumption and increased body weight. Known gender differences in plasma ghrelin levels prompted us to investigate genetic variation of the ghrelin signaling system in females with severe alcohol dependence (n = 113) and in a selected control sample of female low-consumers of alcohol from a large cohort study in southwest Sweden (n = 212). Six tag SNPs in the GHRL (rs696217, rs3491141, rs4684677, rs35680, rs42451, and rs26802) and four tag SNPs in the GHSR (rs495225, rs2232165, rs572169, and rs2948694) were genotyped in all individuals. We found that one GHRL haplotype was associated with reports of paternal alcohol dependence as well as with reports of withdrawal symptoms in the female alcohol-dependent group. Associations with 2 GHSR haplotypes and smoking were also shown. One of these haplotypes was also negatively associated with BMI in controls, while another haplotype was associated with having the early-onset, more heredity-driven, type 2 form of alcohol dependence in the patient group. Taken together, the genes encoding the ghrelin signaling system cannot be regarded as major susceptibility genes for female alcohol dependence, but is, however, involved in paternal heritability and may affect other reward- and energy-related factors such as smoking and BMI.

Reciprocal Interaction of 24-Hour Blood Pressure Variability and Systolic Blood Pressure on Outcome in Stroke Thrombolysis.

PubMed

Kellert, Lars; Hametner, Christian; Ahmed, Niaz; Rauch, Geraldine; MacLeod, Mary J; Perini, Francesco; Lees, Kennedy R; Ringleb, Peter A

2017-07-01

Significance and management of blood pressure (BP) changes in acute stroke care are unclear. Here, we aimed to investigate the impact of 24-hour BP variability (BPV) on outcome in patients with acute ischemic stroke treated with intravenous thrombolysis. From the Safe Implementation of Treatment in Stroke International Stroke Thrombolysis registry, 28 976 patients with documented pre-treatment systolic BP at 2 and 24 hours were analyzed. The primary measure of BP variability was successive variability. Data were preprocessed using coarsened exact matching. We assessed early neurological improvement, symptomatic intracerebral hemorrhage (SICH), and long-term functional outcome (modified Rankin Scale [mRS] at 90 days) by binary and ordinal regression analyses. Attempts to explain successive variation for analysis of BPV with patients characteristics at admission found systolic BP (5.5% variance) to be most influential, yet 92% of BPV variance remained unexplained. Independently from systolic BP, successive variation for analysis of BPV was associated with poor functional outcome mRS score of 0 to 2 (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.90-0.98), disadvantage across the shift of mRS (OR, 1.04; 95% CI, 1.01-1.08), mortality (OR, 1.10; 95% CI, 1.01-1.08), SICH SITS (OR, 1.14; 95% CI, 1.06-1.23), and SICH ECASS (OR, 1.24; 95% CI, 1.10-1.40; ECASS [European Cooperative Acute Stroke Study 2]). Analyzing successive variation for analysis of BPV as a function of pre-treatment, systolic BP significantly improved the prediction of functional outcome (mRS score of 0-1, mRS score of 0-2, neurological improvement, mRS-shift: all P interaction <0.01). Excluding patients with atrial fibrillation in a sensitivity analysis gave consistent results overall. This study suggests the need for a more individual BP management accounting for pre-treatment BP and the acute BP course (ie, BPV) to achieve best possible outcome for the patient. © 2017 American Heart Association, Inc.

The extraneous eclipses on binary light curves: KIC 5255552, KIC 10091110, and KIC 11495766

NASA Astrophysics Data System (ADS)

Zhang, J.; Qian, S. B.; Wang, S. M.; Sun, L. L.; Wu, Y.; Jiang, L. Q.

2018-03-01

Aims: We aim to find more eclipsing multiple systems and obtain their parameters, thus increasing our understanding of multiple systems. Methods: The extraneous eclipses on the Kepler binary light curves indicating extraneous bodies were searched. The binary light curves were analyzed using the binary model, and the extraneous eclipses were studied on their periodicity and shape changes. Results: Three binaries with extraneous eclipses on the binary light curves were found and studied based on the Kepler observations. The object KIC 5255552 is an eclipsing triple system with a fast changing inner binary and an outer companion uncovered by three groups of extraneous eclipses of 862.1(±0.1) d period. The KIC 10091110 is suggested to be a double eclipsing binary system with several possible extraordinary coincidences: the two binaries share similar extremely small mass ratios (0.060(13) and 0.0564(18)), similar mean primary densities (0.3264(42) ρ⊙ and 0.3019(28) ρ⊙), and, most notably, the ratio of the two binaries' periods is very close to integer 2 (8.5303353/4.2185174 = 2.022). The KIC 11495766 is a probable triple system with a 120.73 d period binary and (at least) one non-eclipse companion. Furthermore, very close to it in the celestial sphere, there is a blended background stellar binary of 8.3404432 d period. A first list of 25 eclipsing multiple candidates is presented, with the hope that it will be beneficial for study of eclipsing multiples.

MicroRNAs (MiRs) Precisely Regulate Immune System Development and Function in Immunosenescence Process.

PubMed

Aalaei-Andabili, Seyed Hossein; Rezaei, Nima

2016-01-01

Human aging is a complex process with pivotal changes in gene expression of biological pathways. Immune system dysfunction has been recognized as one of the most important abnormalities induced by senescent names immunosenescence. Emerging evidences suggest miR role in immunosenescence. We aimed to systemically review all relevant reports to clearly state miR effects on immunosenescence process. Sensitive electronic searches carried out. Quality assessment has been performed. Since majority of the included studies were laboratory works, and therefore heterogen, we discussed miR effects on immunological aging process nonstatically. Forty-six articles were found in the initial search. After exclusion of 34 articles, 12 studies enrolled to the final stage. We found that miRs have crucial roles in exact function of immune system. MiRs are involved in the regulation of the aging process in the immune system components and target certain genes, promoting or inhibiting immune system reaction to invasion. Also, miRs control life span of the immune system members by regulation of the genes involved in the apoptosis. Interestingly, we found that immunosenescence is controllable by proper manipulation of the various miRs expression. DNA methylation and histone acetylation have been discovered as novel strategies, altering NF-κB binding ability to the miR promoter sites. Effect of miRs on impairment of immune system function due to the aging is emerging. Although it has been accepted that miRs have determinant roles in the regulation of the immunosenescence; however, most of the reports are concluded from animal/laboratory works, suggesting the necessity of more investigations in human.

Radial Velocities of 41 Kepler Eclipsing Binaries

NASA Astrophysics Data System (ADS)

Matson, Rachel A.; Gies, Douglas R.; Guo, Zhao; Williams, Stephen J.

2017-12-01

Eclipsing binaries are vital for directly determining stellar parameters without reliance on models or scaling relations. Spectroscopically derived parameters of detached and semi-detached binaries allow us to determine component masses that can inform theories of stellar and binary evolution. Here we present moderate resolution ground-based spectra of stars in close binary systems with and without (detected) tertiary companions observed by NASA’s Kepler mission and analyzed for eclipse timing variations. We obtain radial velocities and spectroscopic orbits for five single-lined and 35 double-lined systems, and confirm one false positive eclipsing binary. For the double-lined spectroscopic binaries, we also determine individual component masses and examine the mass ratio {M}2/{M}1 distribution, which is dominated by binaries with like-mass pairs and semi-detached classical Algol systems that have undergone mass transfer. Finally, we constrain the mass of the tertiary component for five double-lined binaries with previously detected companions.

Noise reduction improves memory for target language speech in competing native but not foreign language speech.

PubMed

Ng, Elaine Hoi Ning; Rudner, Mary; Lunner, Thomas; Rönnberg, Jerker

2015-01-01

A hearing aid noise reduction (NR) algorithm reduces the adverse effect of competing speech on memory for target speech for individuals with hearing impairment with high working memory capacity. In the present study, we investigated whether the positive effect of NR could be extended to individuals with low working memory capacity, as well as how NR influences recall performance for target native speech when the masker language is non-native. A sentence-final word identification and recall (SWIR) test was administered to 26 experienced hearing aid users. In this test, target spoken native language (Swedish) sentence lists were presented in competing native (Swedish) or foreign (Cantonese) speech with or without binary masking NR algorithm. After each sentence list, free recall of sentence final words was prompted. Working memory capacity was measured using a reading span (RS) test. Recall performance was associated with RS. However, the benefit obtained from NR was not associated with RS. Recall performance was more disrupted by native than foreign speech babble and NR improved recall performance in native but not foreign competing speech. Noise reduction improved memory for speech heard in competing speech for hearing aid users. Memory for native speech was more disrupted by native babble than foreign babble, but the disruptive effect of native speech babble was reduced to that of foreign babble when there was NR.

The Factory and the Beehive. III. PTFEB132.707+19.810, A Low-mass Eclipsing Binary in Praesepe Observed by PTF and K2

NASA Astrophysics Data System (ADS)

Kraus, Adam L.; Douglas, Stephanie T.; Mann, Andrew W.; Agüeros, Marcel A.; Law, Nicholas M.; Covey, Kevin R.; Feiden, Gregory A.; Rizzuto, Aaron C.; Howard, Andrew W.; Isaacson, Howard; Gaidos, Eric; Torres, Guillermo; Bakos, Gaspar

2017-08-01

Theoretical models of stars constitute the fundamental bedrock upon which much of astrophysics is built, but large swaths of model parameter space remain uncalibrated by observations. The best calibrators are eclipsing binaries in clusters, allowing measurement of masses, radii, luminosities, and temperatures for stars of known metallicity and age. We present the discovery and detailed characterization of PTFEB132.707+19.810, a P = 6.0 day eclipsing binary in the Praesepe cluster (τ ˜ 600-800 Myr [Fe/H] = 0.14 ± 0.04). The system contains two late-type stars (SpT P = M3.5 ± 0.2; SpT S = M4.3 ± 0.7) with precise masses ({M}p=0.3953+/- 0.0020 M ⊙ {M}s=0.2098 +/- 0.0014 M ⊙) and radii ({R}p=0.363+/- 0.008 R ⊙ {R}s=0.272+/- 0.012 R ⊙). Neither star meets the predictions of stellar evolutionary models. The primary has the expected radius but is cooler and less luminous, while the secondary has the expected luminosity but is cooler and substantially larger (by 20%). The system is not tidally locked or circularized. Exploiting a fortuitous 4:5 commensurability between P orb and {P}{rot,{prim}}, we demonstrate that fitting errors from the unknown spot configuration only change the inferred radii by ≲1%-2%. We also analyze subsets of data to test the robustness of radius measurements; the radius sum is more robust to systematic errors and preferable for model comparisons. We also test plausible changes in limb darkening and find corresponding uncertainties of ˜1%. Finally, we validate our pipeline using extant data for GU Boo, finding that our independent results match previous radii to within the mutual uncertainties (2%-3%). We therefore suggest that the substantial discrepancies are astrophysical; since they are larger than those for old field stars, they may be tied to the intermediate age of PTFEB132.707+19.810.

Terrestrial Planet Formation in Binary Star Systems

NASA Technical Reports Server (NTRS)

Lissauer, J. J.; Quintana, E. V.; Adams, F. C.; Chambers, J. E.

2006-01-01

Most stars reside in binary/multiple star systems; however, previous models of planet formation have studied growth of bodies orbiting an isolated single star. Disk material has been observed around one or both components of various young close binary star systems. If planets form at the right places within such disks, they can remain dynamically stable for very long times. We have simulated the late stages of growth of terrestrial planets in both circumbinary disks around 'close' binary star systems with stellar separations ($a_B$) in the range 0.05 AU $\\le a_B \\le$ 0.4 AU and binary eccentricities in the range $0 \\le e \\le 0.8$ and circumstellar disks around individual stars with binary separations of tens of AU. The initial disk of planetary embryos is the same as that used for simulating the late stages of terrestrial planet growth within our Solar System and around individual stars in the Alpha Centauri system (Quintana et al. 2002, A.J., 576, 982); giant planets analogous to Jupiter and Saturn are included if their orbits are stable. The planetary systems formed around close binaries with stellar apastron distances less than or equal to 0.2 AU with small stellar eccentricities are very similar to those formed in the Sun-Jupiter-Saturn, whereas planetary systems formed around binaries with larger maximum separations tend to be sparser, with fewer planets, especially interior to 1 AU. Likewise, when the binary periastron exceeds 10 AU, terrestrial planets can form over essentially the entire range of orbits allowed for single stars with Jupiter-like planets, although fewer terrestrial planets tend to form within high eccentricity binary systems. As the binary periastron decreases, the radial extent of the terrestrial planet systems is reduced accordingly. When the periastron is 5 AU, the formation of Earth-like planets near 1 AU is compromised.

Genetic variants of the folate metabolic system and mild hyperhomocysteinemia may affect ADHD associated behavioral problems.

PubMed

Saha, Tanusree; Chatterjee, Mahasweta; Verma, Deepak; Ray, Anirban; Sinha, Swagata; Rajamma, Usha; Mukhopadhyay, Kanchan

2018-06-08

An etiologically complex disorder, Attention Deficit Hyperactivity Disorder (ADHD), is often associated with various levels of cognitive deficit. Folate/vitamin B 9 is crucial for numerous biochemical pathways including neural stem cell proliferation and differentiation, regulation of gene expression, neurotransmitter synthesis, myelin synthesis and repair, etc. and a scarcity has often been linked to cognitive deficit. Our pilot study in the field revealed significant association of few genetic variants with ADHD. Mild hyperhomocysteinemia and vitamin B 12 deficiency was also noticed in the probands. In the present study additional genetic variants, folate and vitamin B 6 , which may affect folate-homocysteine metabolic pathway, were investigated in 866 individuals including nuclear families with ADHD probands (N=221) and ethnically matched controls (N=286) to find out whether ADHD associated traits are affected by these factors. Population based analysis revealed significant over representation of MTRR rs1801394 "G" allele and "GG" genotype in all as well as male probands. Stratified analysis showed significantly higher frequency of RFC1 rs1051266 and BHMT rs3733890 "AG" genotypes in full term and prematurely delivered ADHD probands respectively. Probands with rs1801394 "GG" genotype and BHMT rs3733890 "G" allele showed association with hyperhomocysteinemia. MTHFR rs1801131, MTR rs1805087 and BHMT rs3733890 also showed association with ADHD index. While rs1051266, rs1801131, and rs1805087 showed association with behavioral problems, rs3733890 was associated with ODD score. Conduct problem exhibited association with RFC1 rs1051266, MTHFR rs1801133 and MTRR rs1801394. Gene-gene interaction analysis revealed positive synergistic interactions between rs1051266, rs1801131 and rs1801394 in the probands as compared to the controls. It can be inferred from the data obtained that folate system genetic variants and mild hyperhomocysteimenia may affect ADHD associated traits by attenuating folate metabolism. Copyright © 2018 Elsevier Inc. All rights reserved.

RS-34 Phoenix In-Space Propulsion System Applied to Active Debris Removal Mission

NASA Technical Reports Server (NTRS)

Esther, Elizabeth A.; Burnside, Christopher G.

2014-01-01

In-space propulsion is a high percentage of the cost when considering Active Debris Removal mission. For this reason it is desired to research if existing designs with slight modification would meet mission requirements to aid in reducing cost of the overall mission. Such a system capable of rendezvous, close proximity operations, and de-orbit of Envisat class resident space objects has been identified in the existing RS-34 Phoenix. RS-34 propulsion system is a remaining asset from the de-commissioned United States Air Force Peacekeeper program; specifically the pressure-fed storable bi-propellant Stage IV Post Boost Propulsion System. The National Aeronautics and Space Administration (NASA) Marshall Space Flight Center (MSFC) gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. Subsequently, MSFC has obtained permission from the USAF to obtain all the remaining RS-34 stages for re-use opportunities. The MSFC Advanced Concepts Office (ACO) was commissioned to lead a study for evaluation of the Rocketdyne produced RS-34 propulsion system as it applies to an active debris removal design reference mission for resident space object targets including Envisat. Originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy payloads at multiple orbital locations. The RS-34 Concept Study lead by sought to further understand application for a similar orbital debris design reference mission to provide propulsive capability for rendezvous, close proximity operations to support the capture phase of the mission, and deorbit of single or multiple large class resident space objects. Multiple configurations varying the degree of modification were identified to trade for dry mass optimization and propellant load. The results of the RS-34 Phoenix Concept Study show that the system is technically sufficient to successfully support all of the missions to rendezvous, capture, and de-orbit targets including Envisat and Hubble Space Telescope. The results and benefits of the RS-34 Orbital Debris Application Concept Study are presented in this paper.

A Bayesian Framework for Generalized Linear Mixed Modeling Identifies New Candidate Loci for Late-Onset Alzheimer’s Disease

PubMed Central

Wang, Xulong; Philip, Vivek M.; Ananda, Guruprasad; White, Charles C.; Malhotra, Ankit; Michalski, Paul J.; Karuturi, Krishna R. Murthy; Chintalapudi, Sumana R.; Acklin, Casey; Sasner, Michael; Bennett, David A.; De Jager, Philip L.; Howell, Gareth R.; Carter, Gregory W.

2018-01-01

Recent technical and methodological advances have greatly enhanced genome-wide association studies (GWAS). The advent of low-cost, whole-genome sequencing facilitates high-resolution variant identification, and the development of linear mixed models (LMM) allows improved identification of putatively causal variants. While essential for correcting false positive associations due to sample relatedness and population stratification, LMMs have commonly been restricted to quantitative variables. However, phenotypic traits in association studies are often categorical, coded as binary case-control or ordered variables describing disease stages. To address these issues, we have devised a method for genomic association studies that implements a generalized LMM (GLMM) in a Bayesian framework, called Bayes-GLMM. Bayes-GLMM has four major features: (1) support of categorical, binary, and quantitative variables; (2) cohesive integration of previous GWAS results for related traits; (3) correction for sample relatedness by mixed modeling; and (4) model estimation by both Markov chain Monte Carlo sampling and maximal likelihood estimation. We applied Bayes-GLMM to the whole-genome sequencing cohort of the Alzheimer’s Disease Sequencing Project. This study contains 570 individuals from 111 families, each with Alzheimer’s disease diagnosed at one of four confidence levels. Using Bayes-GLMM we identified four variants in three loci significantly associated with Alzheimer’s disease. Two variants, rs140233081 and rs149372995, lie between PRKAR1B and PDGFA. The coded proteins are localized to the glial-vascular unit, and PDGFA transcript levels are associated with Alzheimer’s disease-related neuropathology. In summary, this work provides implementation of a flexible, generalized mixed-model approach in a Bayesian framework for association studies. PMID:29507048

The True Ultracool Binary Fraction Using Spectral Binaries

NASA Astrophysics Data System (ADS)

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

2018-01-01

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

Genetic variation in GABRB3 is associated with Asperger syndrome and multiple endophenotypes relevant to autism

PubMed Central

2013-01-01

Background Autism spectrum conditions (ASC) are associated with deficits in social interaction and communication, alongside repetitive, restricted, and stereotyped behavior. ASC is highly heritable. The gamma-aminobutyric acid (GABA)-ergic system has been associated consistently with atypicalities in autism, in both genetic association and expression studies. A key component of the GABA-ergic system is encoded by the GABRB3 gene, which has been previously implicated both in ASC and in individual differences in empathy. Methods In this study, 45 genotyped single nucleotide polymorphisms (SNPs) within GABRB3 were tested for association with Asperger syndrome (AS), and related quantitative traits measured through the following tests: the Empathy Quotient (EQ), the Autism Spectrum Quotient (AQ), the Systemizing Quotient-Revised (SQ-R), the Embedded Figures Test (EFT), the Reading the Mind in the Eyes Test (RMET), and the Mental Rotation Test (MRT). Two-loci, three-loci, four-loci haplotype analyses, and one seven-loci haplotype analysis were also performed in the AS case–control sample. Results Three SNPs (rs7180158, rs7165604, rs12593579) were significantly associated with AS, and two SNPs (rs9806546, rs11636966) were significantly associated with EQ. Two SNP-SNP pairs, rs12438141-rs1035751 and rs12438141-rs7179514, showed significant association with variation in the EFT scores. One SNP-SNP pair, rs7174437-rs1863455, was significantly associated with variation in the MRT scores. Additionally, a few haplotypes, including a 19 kb genomic region that formed a linkage disequilibrium (LD) block in our sample and contained several nominally significant SNPs, were found to be significantly associated with AS. Conclusion The current study confirms the role of GABRB3 as an important candidate gene in both ASC and normative variation in related endophenotypes. PMID:24321478

Comparison of scoring systems for nonvariceal upper gastrointestinal bleeding: a multicenter prospective cohort study.

PubMed

Yang, Hae Min; Jeon, Seong Woo; Jung, Jin Tae; Lee, Dong Wook; Ha, Chang Yoon; Park, Kyung Sik; Lee, Si Hyung; Yang, Chang Heon; Park, Jun Hyung; Park, Youn Sun

2016-01-01

The Glasgow-Blatchford score (GBS) and Rockall score (RS) are widely used to assess risk in patients with upper gastrointestinal bleeding (UGIB). We compared both scoring systems and evaluated their clinical usefulness. Between February 2011 and December 2013, 1584 patients with nonvariceal UGIB were included in the study. A prospective study was conducted to compare the performance of the GBS, pre-RS, and full RS. We compared the performance of these scores using receiver operating characteristic curves. For prediction of the need for hospital-based intervention, the GBS was similar to the full RS (area under the receiver operating characteristic curves [AUROC] 0.705 vs 0.727; P = 0.282) and superior to the pre-RS (AUROC 0.705 vs 0.601; P < 0.0001). In predicting death, the full RS was superior to the GBS (AUROC 0.758 vs 0.644; P = 0.0006) and similar to the pre-RS (AUROC 0.758 vs 0.754; P = 0.869). In predicting rebleeding, the full RS was superior to both GBS (AUROC 0.642 vs 0.585; P = 0.031) and pre-RS (AUROC 0.642 vs 0.593; P = 0.0003). Of 1584 patients, 13 (0.8%) scored 0 on the GBS. Therapeutic intervention was not performed in any of these patients. The GBS is more useful than the pre-RS for predicting the need for hospital-based intervention. A cutoff value of 0 for low-risk patients who might be suitable for outpatient management is useful. The full RS is helpful in predicting death. None of the systems accurately predict rebleeding with a low AUROC. ( cris.nih.go.kr/KCT0000514). © 2015 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

Antinociception by systemically-administered acetaminophen (paracetamol) involves spinal serotonin 5-HT7 and adenosine A1 receptors, as well as peripheral adenosine A1 receptors.

PubMed

Liu, Jean; Reid, Allison R; Sawynok, Jana

2013-03-01

Acetaminophen (paracetamol) is a widely used analgesic, but its sites and mechanisms of action remain incompletely understood. Recent studies have separately implicated spinal adenosine A(1) receptors (A(1)Rs) and serotonin 5-HT(7) receptors (5-HT(7)Rs) in the antinociceptive effects of systemically administered acetaminophen. In the present study, we determined whether these two actions are linked by delivering a selective 5-HT(7)R antagonist to the spinal cord of mice and examining nociception using the formalin 2% model. In normal and A(1)R wild type mice, antinociception by systemic (i.p.) acetaminophen 300mg/kg was reduced by intrathecal (i.t.) delivery of the selective 5-HT(7)R antagonist SB269970 3μg. In mice lacking A(1)Rs, i.t. SB269970 did not reverse antinociception by systemic acetaminophen, indicating a link between spinal 5-HT(7)R and A(1)R mechanisms. We also explored potential roles of peripheral A(1)Rs in antinociception by acetaminophen administered both locally and systemically. In normal mice, intraplantar (i.pl.) acetaminophen 200μg produced antinociception in the formalin test, and this was blocked by co-administration of the selective A(1)R antagonist DPCPX 4.5μg. Acetaminophen administered into the contralateral hindpaw had no effect, indicating a local peripheral action. When acetaminophen was administered systemically, its antinociceptive effect was reversed by i.pl. DPCPX in normal mice; this was also observed in A(1)R wild type mice, but not in those lacking A(1)Rs. In summary, we demonstrate a link between spinal 5-HT(7)Rs and A(1)Rs in the spinal cord relevant to antinociception by systemic acetaminophen. Furthermore, we implicate peripheral A(1)Rs in the antinociceptive effects of locally- and systemically-administered acetaminophen. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Novel SNPs of WNK1 and AKR1C3 are associated with preeclampsia.

PubMed

Sun, Cheng-Juan; Li, Lin; Li, Xueyan; Zhang, Wei-Yuan; Liu, Xiao-Wei

2018-08-20

Preeclampsia is a hypertensive disorder of pregnancy and is one of the most common causes of poor perinatal outcomes. Preeclampsia increases the risk of hypertension in the future. Variants of WNK1 (lysine deficient protein kinase 1), ADRB2 (β2 adrenergic receptor), NEDD4L (ubiquitin-protein ligase NEDD4-like), KLK1 (kallikrein 1) contribute to hypertension, and AKR1C3 (aldo-keto reductase family1 member C3), is associated with preeclampsia. The association of single nucleotide polymorphisms (SNPs) in these five candidate preeclampsia susceptibility genes and the related traits in Chinese individuals were investigated. In this study, 13 SNPs of the five genes were genotyped in 276 preeclampsia patients and 229 age- and area-matched normal pregnancies in women of Chinese Northern Han origin. The 95% confidence interval (CI) and odds ratio (OR) were estimated by binary logistic regression. No obvious linkage disequilibrium or haplotypes were observed among these SNPs. Those with GG genotype and allele G of AKR1C3 (rs10508293) had a decreased risk of preeclampsia (adjusted OR = 3.011, 95% CI = 1.758-5.159, and adjusted OR = 1.745, 95% CI = 1.349-2.257, respectively). The AA genotype and allele A of WNK1 (rs1468326) were significantly associated with an increased risk in preeclampsia (adjusted OR = 2.307, 95% CI = 1.206-3.443, and adjusted OR = 1.663, 95% CI = 1.283-2.157, respectively). The findings indicate that the GG genotype of AKR1C3 rs10508293 is associated with decreased risk for preeclampsia and the AA genotype of WNK1 rs1468326 are related with an increased risk for preeclampsia. Copyright © 2018 Elsevier B.V. All rights reserved.

Constraints on the Progenitor System of the Type Ia Supernova 2014J from Pre-Explosion Hubble Space Telescope Imaging

NASA Technical Reports Server (NTRS)

Kelly, Patrick L.; Fox, Ori D.; Filippenko, Alexei V.; Cenko, S. Bradley; Prato, Lisa; Schaefer, Gail; Shen, Ken J.; Zheng, WeiKang; Graham, Melissa L.; Tucker, Brad E.

2014-01-01

We constrain the properties of the progenitor system of the highly reddened Type Ia supernova (SN Ia) 2014J in Messier 82 (M82; d (is) approx. 3.5 Mpc). We determine the supernova (SN) location using Keck-II K-band adaptive optics images, and we find no evidence for flux from a progenitor system in pre-explosion near-ultraviolet through near-infrared Hubble Space Telescope (HST) images. Our upper limits exclude systems having a bright red giant companion, including symbiotic novae with luminosities comparable to that of RS Ophiuchi. While the flux constraints are also inconsistent with predictions for comparatively cool He-donor systems (T (is) approximately 35,000 K), we cannot preclude a system similar to V445 Puppis. The progenitor constraints are robust across a wide range of RV and AV values, but significantly greater values than those inferred from the SN light curve and spectrum would yield proportionally brighter luminosity limits. The comparatively faint flux expected from a binary progenitor system consisting of white dwarf stars would not have been detected in the pre-explosion HST imaging. Infrared HST exposures yield more stringent constraints on the luminosities of very cool (T (is) less than 3000 K) companion stars than was possible in the case of SN Ia 2011fe.

The SaeRS Two-Component System Controls Survival of Staphylococcus aureus in Human Blood through Regulation of Coagulase

PubMed Central

Guo, Haiyong; Hall, Jeffrey W.; Yang, Junshu; Ji, Yinduo

2017-01-01

The SaeRS two-component system plays important roles in regulation of key virulence factors and pathogenicity. In this study, however, we found that the deletion mutation of saeRS enhanced bacterial survival in human blood, whereas complementation of the mutant with SaeRS returned survival to wild-type levels. Moreover, these phenomena were observed in different MRSA genetic background isolates, including HA-MRSA WCUH29, CA-MRSA 923, and MW2. To elucidate which gene(s) regulated by SaeRS contribute to the effect, we conducted a series of complementation studies with selected known SaeRS target genes in trans. We found coagulase complementation abolished the enhanced survival of the SaeRS mutant in human blood. The coa and saeRS deletion mutants exhibited a similar survival phenotype in blood. Intriguingly, heterologous expression of coagulase decreased survival of S. epidermidis in human blood. Further, the addition of recombinant coagulase to blood significantly decreased the survival of S. aureus. Further, analysis revealed staphylococcal resistance to killing by hydrogen peroxide was partially dependent on the presence or absence of coagulase. Furthermore, complementation with coagulase, but not SaeRS, returned saeRS/coa double mutant survival in blood to wild-type levels. These data indicate SaeRS modulates bacterial survival in blood in coagulase-dependent manner. Our results provide new insights into the role of staphylococcal SaeRS and coagulase on bacterial survival in human blood. PMID:28611950

Association of PTPN22 Single Nucleotide Polymorphisms with Celiac Disease.

PubMed

Aflatounian, Majid; Rezaei, Arezou; Sadr, Maryam; Saghazadeh, Amene; Elhamian, Nazanin; Sadeghi, Hengameh; Motevasselian, Fatemeh; Farahmand, Fatemeh; Fallahi, Gholamhossein; Motamed, Farzaneh; Najafi, Mehri; Rezaei, Nima

2017-06-01

Celiac disease is a chronic autoimmune disease in which gene-environment interactions cause the immune system to unfavorably react to naturally gluten-containing foods. PTPN22 plays a crucial role in regulating the function of various cells of the immune system, particularly T cells. Polymorphisms of the PTPN22 gene have been associated with many autoimmune diseases. The present genetic association study was conducted to investigate the possible associations between PTPNTT single nucleotide polymorphisms (SNPs) and celiac disease in an Iranian population. The study population consisted of 45 patients with celiac disease and 93 healthy controls. The study genotyped five SNPs of the PTPN22 gene: rs12760457, rs1310182, rs1217414, rs33996649, and rs2476601. Control and patient groups did not differ on the genotype distribution of four of five investigated SNPs in the PTPN22 gene, for example, rs12760457, rs2476601, rs1217414, and rs33996649. The only investigated PTPN22 variant, which could be associated with CD, was rs1310182. A significant increase in the carriage of the T allele of rs1310182 in CD patients was observed (OR (95% CI) = 11.42 (5.41, 24.1), p value < 0.0001). The TT genotype of this SNP was significantly associated with celiac disease. Our study suggests that the rs1310182 SNP of PTPN22 gene may be a predisposing factor of celiac disease in the Iranian population. Further studies are required to investigate the issue in other racial and ethnic subgroups.

Functional Polymorphisms of FAS and FASL Gene and Risk of Breast Cancer – Pilot Study of 134 Cases

PubMed Central

Fazaeli, Aliakbar; Eskandari-Nasab, Ebrahim; Arbabi, Farshid; Mashhadi, Mohammad Ali; Taheri, Mohsen; Chaabane, Wiem; Jain, Mayur V.; Łos, Marek J.

2013-01-01

Fas/Fas ligand (FasL) system is one of the key apoptotic signaling entities in the extrinsic apoptotic pathway. De-regulation of this pathway, i.e. by mutations may prevent the immune system from the removal of newly-formed tumor cells, and thus lead to tumor formation. The present study investigated the association between −1377 G/A (rs2234767) and −670 A/G (rs1800682) polymorphisms in Fas as well as single nucleotide polymorphisms INV2nt −124 A/G (rs5030772) and −844 C/T (rs763110) in FasL in a sample of Iranian patients with breast cancer. This case-control study was done on 134 breast cancer patients and 152 normal women. Genomic DNA was extracted from whole blood samples. The polymorphisms were determined by using tetra-ARMS-PCR method. There was no significant difference in the genotype distribution of FAS rs2234767 polymorphism between cases and controls. FAS rs1800682, FASL rs5030772, and FASL rs763110 genotypes showed significant associations with an increasing risk of breast cancer (odds ratio OR = 3.18, P = 0.019; OR = 5.08, P = 0.012; OR = 2.40, P = 0.024, respectively). In conclusion, FAS rs2234767 was not associated with breast cancer risk. Though, FAS rs1800682, FASL rs5030772, and FASL rs763110 polymorphisms were associated with the risk of breast cancer in the examined population. PMID:23326385

New spectroscopic binary companions of giant stars and updated metallicity distribution for binary systems

NASA Astrophysics Data System (ADS)

Bluhm, P.; Jones, M. I.; Vanzi, L.; Soto, M. G.; Vos, J.; Wittenmyer, R. A.; Drass, H.; Jenkins, J. S.; Olivares, F.; Mennickent, R. E.; Vučković, M.; Rojo, P.; Melo, C. H. F.

2016-10-01

We report the discovery of 24 spectroscopic binary companions to giant stars. We fully constrain the orbital solution for 6 of these systems. We cannot unambiguously derive the orbital elements for the remaining stars because the phase coverage is incomplete. Of these stars, 6 present radial velocity trends that are compatible with long-period brown dwarf companions. The orbital solutions of the 24 binary systems indicate that these giant binary systems have a wide range in orbital periods, eccentricities, and companion masses. For the binaries with restricted orbital solutions, we find a range of orbital periods of between ~97-1600 days and eccentricities of between ~0.1-0.4. In addition, we studied the metallicity distribution of single and binary giant stars. We computed the metallicity of a total of 395 evolved stars, 59 of wich are in binary systems. We find a flat distribution for these binary stars and therefore conclude that stellar binary systems, and potentially brown dwarfs, have a different formation mechanism than planets. This result is confirmed by recent works showing that extrasolar planets orbiting giants are more frequent around metal-rich stars. Finally, we investigate the eccentricity as a function of the orbital period. We analyzed a total of 130 spectroscopic binaries, including those presented here and systems from the literature. We find that most of the binary stars with periods ≲30 days have circular orbits, while at longer orbital periods we observe a wide spread in their eccentricities. Based on observations collected at La Silla - Paranal Observatory under programs IDs IDs 085.C-0557, 087.C.0476, 089.C-0524, 090.C-0345, 096.A-9020 and through the Chilean Telescope Time under programs IDs CN2012A-73, CN2012B-47, CN2013A-111, CN2013B-51, CN2014A-52 and CN2015A-48.

On the frequency of close binary systems among very low-mass stars and brown dwarfs

NASA Astrophysics Data System (ADS)

Maxted, P. F. L.; Jeffries, R. D.

2005-09-01

We have used Monte Carlo simulation techniques and published radial velocity surveys to constrain the frequency of very low-mass star (VLMS) and brown dwarf (BD) binary systems and their separation (a) distribution. Gaussian models for the separation distribution with a peak at a= 4au and 0.6 <=σlog(a/au)<= 1.0, correctly predict the number of observed binaries, yielding a close (a < 2.6au) binary frequency of 17-30 per cent and an overall VLMS/BD binary frequency of 32-45 per cent. We find that the available N-body models of VLMS/BD formation from dynamically decaying protostellar multiple systems are excluded at >99 per cent confidence because they predict too few close binary VLMS/BDs. The large number of close binaries and high overall binary frequency are also very inconsistent with recent smoothed particle hydrodynamical modelling and argue against a dynamical origin for VLMS/BDs.

AmgRS-mediated envelope stress-inducible expression of the mexXY multidrug efflux operon of Pseudomonas aeruginosa

PubMed Central

Lau, Calvin Ho-Fung; Krahn, Thomas; Gilmour, Christie; Mullen, Erin; Poole, Keith

2015-01-01

AmgRS is an envelope stress-responsive two-component system and aminoglycoside resistance determinant in Pseudomonas aeruginosa that is proposed to protect cells from membrane damage caused by aminoglycoside-generated mistranslated polypeptides. Consistent with this, a ΔamgR strain showed increased aminoglycoside-promoted membrane damage, damage that was largely absent in AmgRS-activated amgS-mutant strains. Intriguingly, one such mutation, V121G, while providing for enhanced resistance to aminoglycosides, rendered P. aeruginosa susceptible to several ribosome-targeting nonaminoglycoside antimicrobials that are inducers and presumed substrates of the MexXY-OprM multidrug efflux system. Surprisingly, the amgSV121G mutation increased mexXY expression threefold, suggesting that export of these nonaminoglycosides was compromised in the amgSV121G mutant. Nonetheless, a link was established between AmgRS activation and mexXY expression and this was confirmed in studies showing that aminoglycoside-promoted mexXY expression is dependent on AmgRS. While nonaminoglycosides also induced mexXY expression, this was not AmgRS-dependent, consistent with these agents not generating mistranslated polypeptides and not activating AmgRS. The aminoglycoside inducibility of mexXY was abrogated in a mutant lacking the AmgRS target genes htpX and PA5528, encoding a presumed cytoplasmic membrane-associated protease and a membrane protein of unknown function, respectively. Thus, aminoglycoside induction of mexXY is a response to membrane damage and activation of the AmgRS two-component system. PMID:25450797

Interferon regulatory factor 5 gene polymorphism in Egyptian children with systemic lupus erythematosus.

PubMed

Hammad, A; Mossad, Y M; Nasef, N; Eid, R

2017-07-01

Background Increased expression of interferon-inducible genes is implicated in the pathogenesis of systemic lupus erythematosus (SLE). Interferon regulatory factor 5 (IRF5) is one of the transcription factors regulating interferon and was proved to be implicated in the pathogenesis of SLE in different populations. Objectives The objective of this study was to investigate the correlation between polymorphisms of the IRF5 gene and SLE susceptibility in a cohort of Egyptian children and to investigate their association with clinico-pathological features, especially lupus nephritis. Subjects and methods Typing of interferon regulatory factor 5 rs10954213, rs2004640 and rs2280714 polymorphisms were done using polymerase chain reaction-restriction fragment length polymorphism for 100 children with SLE and 100 matched healthy controls. Results Children with SLE had more frequent T allele and TT genotype of rs2004640 ( P c  = 0.003 and 0.024, respectively) compared to controls. Patients with nephritis had more frequent T allele of rs2004640 compared to controls ( P c  = 0.003). However the allele and genotype frequencies of the three studied polymorphisms did not show any difference in patients with nephritis in comparison to those without nephritis. Haplotype GTA of rs10954213, rs2004640 and rs2280714, respectively, was more frequent in lupus patients in comparison to controls ( p = 0.01) while the haplotype GGG was more frequent in controls than lupus patients ( p = 0.011). Conclusion The rs2004640 T allele and TT genotype and GTA haplotype of rs rs10954213, rs2004640, and rs2280714, respectively, can be considered as risk factors for the development of SLE. The presence of the rs2004640 T allele increases the risk of nephritis development in Egyptian children with SLE.

Detecting the Companions and Ellipsoidal Variations of RS CVn Primaries. II. o Draconis, a Candidate for Recent Low-mass Companion Ingestion

NASA Astrophysics Data System (ADS)

Roettenbacher, Rachael M.; Monnier, John D.; Fekel, Francis C.; Henry, Gregory W.; Korhonen, Heidi; Latham, David W.; Muterspaugh, Matthew W.; Williamson, Michael H.; Baron, Fabien; ten Brummelaar, Theo A.; Che, Xiao; Harmon, Robert O.; Schaefer, Gail H.; Scott, Nicholas J.; Sturmann, Judit; Sturmann, Laszlo; Turner, Nils H.

2015-08-01

To measure the stellar and orbital properties of the metal-poor RS CVn binary o Draconis (o Dra), we directly detect the companion using interferometric observations obtained with the Michigan InfraRed Combiner at Georgia State University's Center for High Angular Resolution Astronomy (CHARA) Array. The H-band flux ratio between the primary and secondary stars is the highest confirmed flux ratio (370 ± 40) observed with long-baseline optical interferometry. These detections are combined with radial velocity data of both the primary and secondary stars, including new data obtained with the Tillinghast Reflector Echelle Spectrograph on the Tillinghast Reflector at the Fred Lawrence Whipple Observatory and the 2 m Tennessee State University Automated Spectroscopic Telescope at Fairborn Observatory. We determine an orbit from which we find model-independent masses and ages of the components ({M}A=1.35+/- 0.05 {M}⊙ , {M}B=0.99+/- 0.02 {M}⊙ , system age = 3.0\\mp 0.5 Gyr). An average of a 23-year light curve of o Dra from the Tennessee State University Automated Photometric Telescope folded over the orbital period newly reveals eclipses and the quasi-sinusoidal signature of ellipsoidal variations. The modeled light curve for our system's stellar and orbital parameters confirm these ellipsoidal variations due to the primary star partially filling its Roche lobe potential, suggesting most of the photometric variations are not due to stellar activity (starspots). Measuring gravity darkening from the average light curve gives a best-fit of β =0.07+/- 0.03, a value consistent with conventional theory for convective envelope stars. The primary star also exhibits an anomalously short rotation period, which, when taken with other system parameters, suggests the star likely engulfed a low-mass companion that had recently spun-up the star.

Search for Gravitational Waves from Low Mass Compact Binary Coalescence in LIGO's Sixth Science Run and Virgo's Science Runs 2 and 3

NASA Technical Reports Server (NTRS)

Abadie, J.; Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M.; Accadia, T.; Acernese, F.; Adams, C.; Adhikari, R.; Affeldt, C.;

Search for gravitational waves from low mass compact binary coalescence in LIGO's sixth science run and Virgo's science runs 2 and 3

NASA Astrophysics Data System (ADS)

Abadie, J.; Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M.; Accadia, T.; Acernese, F.; Adams, C.; Adhikari, R.; Affeldt, C.; Agathos, M.; Ajith, P.; Allen, B.; Allen, G. S.; Amador Ceron, E.; Amariutei, D.; Amin, R. S.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Arain, M. A.; Araya, M. C.; Aston, S. M.; Astone, P.; Atkinson, D.; Aufmuth, P.; Aulbert, C.; Aylott, B. E.; Babak, S.; Baker, P.; Ballardin, G.; Ballmer, S.; Barker, D.; Barone, F.; Barr, B.; Barriga, P.; Barsotti, L.; Barsuglia, M.; Barton, M. A.; Bartos, I.; Bassiri, R.; Bastarrika, M.; Basti, A.; Batch, J.; Bauchrowitz, J.; Bauer, Th. S.; Bebronne, M.; Behnke, B.; Beker, M. G.; Bell, A. S.; Belletoile, A.; Belopolski, I.; Benacquista, M.; Berliner, J. M.; Bertolini, A.; Betzwieser, J.; Beveridge, N.; Beyersdorf, P. T.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Biswas, R.; Bitossi, M.; Bizouard, M. A.; Black, E.; Blackburn, J. K.; Blackburn, L.; Blair, D.; Bland, B.; Blom, M.; Bock, O.; Bodiya, T. P.; Bogan, C.; Bondarescu, R.; Bondu, F.; Bonelli, L.; Bonnand, R.; Bork, R.; Born, M.; Boschi, V.; Bose, S.; Bosi, L.; Bouhou, B.; Braccini, S.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Breyer, J.; Briant, T.; Bridges, D. O.; Brillet, A.; Brinkmann, M.; Brisson, V.; Britzger, M.; Brooks, A. F.; Brown, D. A.; Brummit, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Burguet–Castell, J.; Burmeister, O.; Buskulic, D.; Buy, C.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Calloni, E.; Camp, J. B.; Campsie, P.; Cannizzo, J.; Cannon, K.; Canuel, B.; Cao, J.; Capano, C. D.; Carbognani, F.; Caride, S.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C.; Cesarini, E.; Chaibi, O.; Chalermsongsak, T.; Chalkley, E.; Charlton, P.; Chassande-Mottin, E.; Chelkowski, S.; Chen, Y.; Chincarini, A.; Chiummo, A.; Cho, H.; Christensen, N.; Chua, S. S. Y.; Chung, C. T. Y.; Chung, S.; Ciani, G.; Clara, F.; Clark, D. E.; Clark, J.; Clayton, J. H.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colacino, C. N.; Colas, J.; Colla, A.; Colombini, M.; Conte, A.; Conte, R.; Cook, D.; Corbitt, T. R.; Cordier, M.; Cornish, N.; Corsi, A.; Costa, C. A.; Coughlin, M.; Coulon, J.-P.; Couvares, P.; Coward, D. M.; Coyne, D. C.; Creighton, J. D. E.; Creighton, T. D.; Cruise, A. M.; Cumming, A.; Cunningham, L.; Cuoco, E.; Cutler, R. M.; Dahl, K.; Danilishin, S. L.; Dannenberg, R.; D'Antonio, S.; Danzmann, K.; Dattilo, V.; Daudert, B.; Daveloza, H.; Davier, M.; Davies, G.; Daw, E. J.; Day, R.; Dayanga, T.; De Rosa, R.; DeBra, D.; Debreczeni, G.; Degallaix, J.; Del Pozzo, W.; del Prete, M.; Dent, T.; Dergachev, V.; DeRosa, R.; DeSalvo, R.; Dhurandhar, S.; Di Fiore, L.; Di Lieto, A.; Di Palma, I.; Di Paolo Emilio, M.; Di Virgilio, A.; Díaz, M.; Dietz, A.; DiGuglielmo, J.; Donovan, F.; Dooley, K. L.; Dorsher, S.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Dumas, J.-C.; Dwyer, S.; Eberle, T.; Edgar, M.; Edwards, M.; Effler, A.; Ehrens, P.; Endrőczi, G.; Engel, R.; Etzel, T.; Evans, K.; Evans, M.; Evans, T.; Factourovich, M.; Fafone, V.; Fairhurst, S.; Fan, Y.; Farr, B. F.; Farr, W.; Fazi, D.; Fehrmann, H.; Feldbaum, D.; Ferrante, I.; Fidecaro, F.; Finn, L. S.; Fiori, I.; Fisher, R. P.; Flaminio, R.; Flanigan, M.; Foley, S.; Forsi, E.; Forte, L. A.; Fotopoulos, N.; Fournier, J.-D.; Franc, J.; Frasca, S.; Frasconi, F.; Frede, M.; Frei, M.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T. T.; Friedrich, D.; Fritschel, P.; Frolov, V. V.; Fulda, P. J.; Fyffe, M.; Galimberti, M.; Gammaitoni, L.; Ganija, M. R.; Garcia, J.; Garofoli, J. A.; Garufi, F.; Gáspár, M. E.; Gemme, G.; Geng, R.; Genin, E.; Gennai, A.; Gergely, L. Á.; Ghosh, S.; Giaime, J. A.; Giampanis, S.; Giardina, K. D.; Giazotto, A.; Gill, C.; Goetz, E.; Goggin, L. M.; González, G.; Gorodetsky, M. L.; Goßler, S.; Gouaty, R.; Graef, C.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Gray, N.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Greverie, C.; Grosso, R.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guido, C.; Gupta, R.; Gustafson, E. K.; Gustafson, R.; Ha, T.; Hage, B.; Hallam, J. M.; Hammer, D.; Hammond, G.; Hanks, J.; Hanna, C.; Hanson, J.; Hardt, A.; Harms, J.; Harry, G. M.; Harry, I. W.; Harstad, E. D.; Hartman, M. T.; Haughian, K.; Hayama, K.; Hayau, J.-F.; Heefner, J.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hendry, M. A.; Heng, I. S.; Heptonstall, A. W.; Herrera, V.; Hewitson, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Holt, K.; Hong, T.; Hooper, S.; Hosken, D. J.; Hough, J.; Howell, E. J.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Ingram, D. R.; Inta, R.; Isogai, T.; Ivanov, A.; Izumi, K.; Jacobson, M.; Jang, H.; Jaranowski, P.; Johnson, W. W.; Jones, D. I.; Jones, G.; Jones, R.; Ju, L.; Kalmus, P.; Kalogera, V.; Kamaretsos, I.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Katsavounidis, E.; Katzman, W.; Kaufer, H.; Kawabe, K.; Kawamura, S.; Kawazoe, F.; Kells, W.; Keppel, D. G.; Keresztes, Z.; Khalaidovski, A.; Khalili, F. Y.; Khazanov, E. A.; Kim, B.; Kim, C.; Kim, D.; Kim, H.; Kim, K.; Kim, N.; Kim, Y.-M.; King, P. J.; Kinsey, M.; Kinzel, D. L.; Kissel, J. S.; Klimenko, S.; Kokeyama, K.; Kondrashov, V.; Kopparapu, R.; Koranda, S.; Korth, W. Z.; Kowalska, I.; Kozak, D.; Kringel, V.; Krishnamurthy, S.; Krishnan, B.; Królak, A.; Kuehn, G.; Kumar, R.; Kwee, P.; Lam, P. K.; Landry, M.; Lang, M.; Lantz, B.; Lastzka, N.; Lawrie, C.; Lazzarini, A.; Leaci, P.; Lee, C. H.; Lee, H. M.; Leindecker, N.; Leong, J. R.; Leonor, I.; Leroy, N.; Letendre, N.; Li, J.; Li, T. G. F.; Liguori, N.; Lindquist, P. E.; Lockerbie, N. A.; Lodhia, D.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Luan, J.; Lubinski, M.; Lück, H.; Lundgren, A. P.; Macdonald, E.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Mageswaran, M.; Mailand, K.; Majorana, E.; Maksimovic, I.; Man, N.; Mandel, I.; Mandic, V.; Mantovani, M.; Marandi, A.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markosyan, A.; Maros, E.; Marque, J.; Martelli, F.; Martin, I. W.; Martin, R. M.; Marx, J. N.; Mason, K.; Masserot, A.; Matichard, F.; Matone, L.; Matzner, R. A.; Mavalvala, N.; Mazzolo, G.; McCarthy, R.; McClelland, D. E.; McGuire, S. C.; McIntyre, G.; McIver, J.; McKechan, D. J. A.; Meadors, G. D.; Mehmet, M.; Meier, T.; Melatos, A.; Melissinos, A. C.; Mendell, G.; Menendez, D.; Mercer, R. A.; Meshkov, S.; Messenger, C.; Meyer, M. S.; Miao, H.; Michel, C.; Milano, L.; Miller, J.; Minenkov, Y.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Miyakawa, O.; Moe, B.; Moesta, P.; Mohan, M.; Mohanty, S. D.; Mohapatra, S. R. P.; Moraru, D.; Moreno, G.; Morgado, N.; Morgia, A.; Mori, T.; Mosca, S.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, C. L.; Mueller, G.; Mukherjee, S.; Mullavey, A.; Müller-Ebhardt, H.; Munch, J.; Murphy, D.; Murray, P. G.; Mytidis, A.; Nash, T.; Naticchioni, L.; Nawrodt, R.; Necula, V.; Nelson, J.; Newton, G.; Nishizawa, A.; Nocera, F.; Nolting, D.; Nuttall, L.; Ochsner, E.; O'Dell, J.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Oldenburg, R. G.; O'Reilly, B.; O'Shaughnessy, R.; Osthelder, C.; Ott, C. D.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Page, A.; Pagliaroli, G.; Palladino, L.; Palomba, C.; Pan, Y.; Pankow, C.; Paoletti, F.; Papa, M. A.; Parisi, M.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patel, P.; Pedraza, M.; Peiris, P.; Pekowsky, L.; Penn, S.; Peralta, C.; Perreca, A.; Persichetti, G.; Phelps, M.; Pickenpack, M.; Piergiovanni, F.; Pietka, M.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Pletsch, H. J.; Plissi, M. V.; Poggiani, R.; Pöld, J.; Postiglione, F.; Prato, M.; Predoi, V.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prix, R.; Prodi, G. A.; Prokhorov, L.; Puncken, O.; Punturo, M.; Puppo, P.; Quetschke, V.; Raab, F. J.; Rabeling, D. S.; Rácz, I.; Radkins, H.; Raffai, P.; Rakhmanov, M.; Ramet, C. R.; Rankins, B.; Rapagnani, P.; Raymond, V.; Re, V.; Redwine, K.; Reed, C. M.; Reed, T.; Regimbau, T.; Reid, S.; Reitze, D. H.; Ricci, F.; Riesen, R.; Riles, K.; Robertson, N. A.; Robinet, F.; Robinson, C.; Robinson, E. L.; Rocchi, A.; Roddy, S.; Rodriguez, C.; Rodruck, M.; Rolland, L.; Rollins, J.; Romano, J. D.; Romano, R.; Romie, J. H.; Rosińska, D.; Röver, C.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Ryll, H.; Sainathan, P.; Sakosky, M.; Salemi, F.; Samblowski, A.; Sammut, L.; Sancho de la Jordana, L.; Sandberg, V.; Sankar, S.; Sannibale, V.; Santamaría, L.; Santiago-Prieto, I.; Santostasi, G.; Sassolas, B.; Sathyaprakash, B. S.; Sato, S.; Saulson, P. R.; Savage, R. L.; Schilling, R.; Schlamminger, S.; Schnabel, R.; Schofield, R. M. S.; Schulz, B.; Schutz, B. F.; Schwinberg, P.; Scott, J.; Scott, S. M.; Searle, A. C.; Seifert, F.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sergeev, A.; Shaddock, D. A.; Shaltev, M.; Shapiro, B.; Shawhan, P.; Shoemaker, D. H.; Sibley, A.; Siemens, X.; Sigg, D.; Singer, A.; Singer, L.; Sintes, A. M.; Skelton, G.; Slagmolen, B. J. J.; Slutsky, J.; Smith, J. R.; Smith, M. R.; Smith, N. D.; Smith, R. J. E.; Somiya, K.; Sorazu, B.; Soto, J.; Speirits, F. C.; Sperandio, L.; Stefszky, M.; Stein, A. J.; Steinert, E.; Steinlechner, J.; Steinlechner, S.; Steplewski, S.; Stochino, A.; Stone, R.; Strain, K. A.; Strigin, S.; Stroeer, A. S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sung, M.; Susmithan, S.; Sutton, P. J.; Swinkels, B.; Tacca, M.; Taffarello, L.; Talukder, D.; Tanner, D. B.; Tarabrin, S. P.; Taylor, J. R.; Taylor, R.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Thüring, A.; Titsler, C.; Tokmakov, K. V.; Toncelli, A.; Tonelli, M.; Torre, O.; Torres, C.; Torrie, C. I.; Tournefier, E.; Travasso, F.; Traylor, G.; Trias, M.; Tseng, K.; Tucker, E.; Ugolini, D.; Urbanek, K.; Vahlbruch, H.; Vajente, G.; Vallisneri, M.; van den Brand, J. F. J.; Van Den Broeck, C.; van der Putten, S.; van Veggel, A. A.; Vass, S.; Vasuth, M.; Vaulin, R.; Vavoulidis, M.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Veltkamp, C.; Verkindt, D.; Vetrano, F.; Viceré, A.; Villar, A. E.; Vinet, J.-Y.; Vitale, S.; Vitale, S.; Vocca, H.; Vorvick, C.; Vyatchanin, S. P.; Wade, A.; Waldman, S. J.; Wallace, L.; Wan, Y.; Wang, X.; Wang, Z.; Wanner, A.; Ward, R. L.; Was, M.; Wei, P.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Wen, S.; Wessels, P.; West, M.; Westphal, T.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; White, D.; Whiting, B. F.; Wilkinson, C.; Willems, P. A.; Williams, H. R.; Williams, L.; Willke, B.; Winkelmann, L.; Winkler, W.; Wipf, C. C.; Wiseman, A. G.; Wittel, H.; Woan, G.; Wooley, R.; Worden, J.; Yablon, J.; Yakushin, I.; Yamamoto, H.; Yamamoto, K.; Yang, H.; Yeaton-Massey, D.; Yoshida, S.; Yu, P.; Yvert, M.; Zadroźny, A.; Zanolin, M.; Zendri, J.-P.; Zhang, F.; Zhang, L.; Zhang, W.; Zhang, Z.; Zhao, C.; Zotov, N.; Zucker, M. E.; Zweizig, J.

2012-04-01

We report on a search for gravitational waves from coalescing compact binaries using LIGO and Virgo observations between July 7, 2009, and October 20, 2010. We searched for signals from binaries with total mass between 2 and 25M⊙; this includes binary neutron stars, binary black holes, and binaries consisting of a black hole and neutron star. The detectors were sensitive to systems up to 40 Mpc distant for binary neutron stars, and further for higher mass systems. No gravitational-wave signals were detected. We report upper limits on the rate of compact binary coalescence as a function of total mass, including the results from previous LIGO and Virgo observations. The cumulative 90% confidence rate upper limits of the binary coalescence of binary neutron star, neutron star-black hole, and binary black hole systems are 1.3×10-4, 3.1×10-5, and 6.4×10-6Mpc-3yr-1, respectively. These upper limits are up to a factor 1.4 lower than previously derived limits. We also report on results from a blind injection challenge.

Contact binaries in the Trans-neptunian Belt

NASA Astrophysics Data System (ADS)

Thirouin, Audrey; Sheppard, Scott S.

2017-10-01

A contact binary is made up of two objects that are almost touching or in contact with each other. These systems have been found in the Near-Earth Object population, the main belt of asteroids, the Jupiter Trojans, the comet population and even in the Trans-neptunian belt.Several studies suggest that up to 30% of the Trans-Neptunian Objects (TNOs) could be contact binaries (Sheppard & Jewitt 2004, Lacerda 2011). Contact binaries are not resolvable with the Hubble Space Telescope because of the small separation between the system's components (Noll et al. 2008). Only lightcurves with a characteristic V-/U-shape at the minimum/maximum of brightness and a large amplitude can identify these contact binaries. Despite an expected high fraction of contact binaries, 2001 QG298 is the only confirmed contact binary in the Trans-Neptunian belt, and 2003 SQ317 is a candidate to this class of systems (Sheppard & Jewitt 2004, Lacerda et al. 2014).Recently, using the Lowell’s 4.3m Discovery Channel Telescope and the 6.5m Magellan Telescope, we started a search for contact binaries at the edge of our Solar System. So far, our survey focused on about 40 objects in different dynamical groups of the Trans-Neptunian belt for sparse or complete lightcurves. We report the discovery of 5 new potential contact binaries converting the current estimate of potential/confirmed contact binaries to 7 objects. With one epoch of observations per object, we are not able to model in detail the systems, but we derive estimate for basic information such as shape, size, density of both objects as well as the separation between the system’s components. In this work, we will present these new systems, their basic characteristics, and we will discuss the potential main reservoir of contact binaries in the Trans-neptunian belt.

Photometric binary stars in Praesepe and the search for globular cluster binaries

NASA Technical Reports Server (NTRS)

Bolte, Michael

1991-01-01

A radial velocity study of the stars which are located on a second sequence above the single-star zero-age main sequence at a given color in the color-magnitude diagram of the open cluster Praesepe, (NGC 2632) shows that 10, and possibly 11, of 17 are binary systems. Of the binary systems, five have full amplitudes for their velocity variations that are greater than 50 km/s. To the extent that they can be applied to globular clusters, these results suggests that (1) observations of 'second-sequence' stars in globular clusters would be an efficient way of finding main-sequence binary systems in globulars, and (2) current instrumentation on large telescopes is sufficient for establishing unambiguously the existence of main-sequence binary systems in nearby globular clusters.

Adsorption of Cr(VI) on cerium immobilized cross-linked chitosan composite in single system and coexisted with Orange II in binary system.

PubMed

Zhu, Tianyi; Huang, Wei; Zhang, Lingfan; Gao, Jie; Zhang, Wenqing

2017-10-01

In this work, cerium immobilized cross-linked chitosan (CTS-Ce) composite, employed as an efficient adsorbent for Cr(VI) in single system and coexisted with Orange II (OII) in binary system, was prepared by co-precipitation method. The as-obtained adsorbent was characterized by FTIR, SEM, EDS and XPS before and after adsorption. The adsorption behaviors of Cr(VI) in single and binary system were systematically studied. The maximum adsorption capacity of Cr(VI) on CTS-Ce (202.8mg/g) was calculated by Langmuir equation in single metal system, but it decreased to 112.9mg/g with initial concentration of 100mg/L OII in binary system at pH 2 and 293K. The adsorption data for Cr(VI) followed the Langmuir model in single system, while fitted Temkin model well in binary system. In both single and binary system, the kinetics of adsorption exhibited pseudo-second order behavior and adsorption capacity increased with increasing temperature. Moreover, the data of thermodynamic parameters (ΔG°<0, ΔH°>0) indicated that the adsorption was a spontaneous and endothermic process. Besides, |ΔG Cr |>|ΔG Cr-OII | at the same temperature further suggested that Cr(VI) was adsorbed on the CTS-Ce composite faster in binary system than in single system. Copyright © 2017 Elsevier B.V. All rights reserved.

A global regulatory system links virulence and antibiotic resistance to envelope homeostasis in Acinetobacter baumannii.

PubMed

Geisinger, Edward; Mortman, Nadav J; Vargas-Cuebas, Germán; Tai, Albert K; Isberg, Ralph R

2018-05-01

The nosocomial pathogen Acinetobacter baumannii is a significant threat due to its ability to cause infections refractory to a broad range of antibiotic treatments. We show here that a highly conserved sensory-transduction system, BfmRS, mediates the coordinate development of both enhanced virulence and resistance in this microorganism. Hyperactive alleles of BfmRS conferred increased protection from serum complement killing and allowed lethal systemic disease in mice. BfmRS also augmented resistance and tolerance against an expansive set of antibiotics, including dramatic protection from β-lactam toxicity. Through transcriptome profiling, we showed that BfmRS governs these phenotypes through global transcriptional regulation of a post-exponential-phase-like program of gene expression, a key feature of which is modulation of envelope biogenesis and defense pathways. BfmRS activity defended against cell-wall lesions through both β-lactamase-dependent and -independent mechanisms, with the latter being connected to control of lytic transglycosylase production and proper coordination of morphogenesis and division. In addition, hypersensitivity of bfmRS knockouts could be suppressed by unlinked mutations restoring a short, rod cell morphology, indicating that regulation of drug resistance, pathogenicity, and envelope morphogenesis are intimately linked by this central regulatory system in A. baumannii. This work demonstrates that BfmRS controls a global regulatory network coupling cellular physiology to the ability to cause invasive, drug-resistant infections.

International Ultraviolet Explorer observations of the peculiar variable spectrum of the eclipsing binary R Arae

NASA Technical Reports Server (NTRS)

Mccluskey, G. E.; Kondo, Y.

1983-01-01

The eclipsing binary system R Arae = HD 149730 is a relatively bright southern system with an orbital period of about 4.4 days. It is a single-lined spectroscopic binary. The spectral class of the primary component is B9 Vp. The system was included in a study of mass flow and evolution in close binary systems using the International Ultraviolet Explorer satellite (IUE). Four spectra in the wavelength range from 1150 to 1900 A were obtained with the far-ultraviolet SWP camera, and six spectra in the range from 1900 to 3200 range were obtained with the mid-ultraviolet LWR camera. The close binary R Arae exhibits very unusual ultraviolet spectra. It appears that no other close binary system, observed with any of the orbiting satellites, shows outside-eclipse ultraviolet continuum flux variations of this nature.

On the Induced Gravitational Collapse

NASA Astrophysics Data System (ADS)

Becerra, Laura M.; Bianco, Carlo; Fryer, Chris; Rueda, Jorge; Ruffini, Remo

2018-01-01

The induced gravitational collapse (IGC) paradigm has been applied to explain the long gamma ray burst (GRB) associated with type Ic supernova, and recently the Xray flashes (XRFs). The progenitor is a binary systems of a carbon-oxygen core (CO) and a neutron star (NS). The CO core collapses and undergoes a supernova explosion which triggers the hypercritical accretion onto the NS companion (up to 10-2 M⊙s-1). For the binary driven hypernova (BdHNe), the binary system is enough bound, the NS reach its critical mass, and collapse to a black hole (BH) with a GRB emission characterized by an isotropic energy Eiso > 1052 erg. Otherwise, for binary systems with larger binary separations, the hypercritical accretion onto the NS is not sufficient to induced its gravitational collapse, a X-ray flash is produced with Eiso < 1052 erg. We're going to focus in identify the binary parameters that limits the BdHNe systems with the XRFs systems.

IOTA: recent science and technology

NASA Astrophysics Data System (ADS)

Schloerb, F. Peter; Berger, J.-P.; Carleton, N. P.; Hagenauer, P.; Kern, P. Y.; Labeye, P. R.; Lacasse, M. G.; Malbet, F.; Millan-Gabet, R.; Monnier, J. D.; Pearlman, M. R.; Pedretti, E.; Rousselet-Perraut, K.; Ragland, S. D.; Schuller, P. A.; Traub, W. A.; Wallace, G.

2006-06-01

We present a brief review of recent scientific and technical advances at the Infrared Optical Telescope Array (IOTA). IOTA is a long-baseline interferometer located atop Mount Hopkins, Arizona. Recent work has emphasized the use of the three-telescope interferometer completed in 2002. We report on results obtained on a range of scientific targets, including AGB stars, Herbig AeBe Stars, binary stars, and the recent outburst of the recurrent nova RS Oph. We report the completion of a new spectrometer which allows visibility measurements at several high spectral resolution channels simultaneously. Finally, it is our sad duty to report that IOTA will be closed this year.

The incidence of stellar mergers and mass gainers among massive stars

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

De Mink, S. E.; Sana, H.; Langer, N.

2014-02-10

Because the majority of massive stars are born as members of close binary systems, populations of massive main-sequence stars contain stellar mergers and products of binary mass transfer. We simulate populations of massive stars accounting for all major binary evolution effects based on the most recent binary parameter statistics and extensively evaluate the effect of model uncertainties. Assuming constant star formation, we find that 8{sub −4}{sup +9}% of a sample of early-type stars are the products of a merger resulting from a close binary system. In total we find that 30{sub −15}{sup +10}% of massive main-sequence stars are the productsmore » of binary interaction. We show that the commonly adopted approach to minimize the effects of binaries on an observed sample by excluding systems detected as binaries through radial velocity campaigns can be counterproductive. Systems with significant radial velocity variations are mostly pre-interaction systems. Excluding them substantially enhances the relative incidence of mergers and binary products in the non-radial velocity variable sample. This poses a challenge for testing single stellar evolutionary models. It also raises the question of whether certain peculiar classes of stars, such as magnetic O stars, are the result of binary interaction and it emphasizes the need to further study the effect of binarity on the diagnostics that are used to derive the fundamental properties (star-formation history, initial mass function, mass-to-light ratio) of stellar populations nearby and at high redshift.« less

BINARY CENTRAL STARS OF PLANETARY NEBULAE DISCOVERED THROUGH PHOTOMETRIC VARIABILITY. IV. THE CENTRAL STARS OF HaTr 4 AND Hf 2-2

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

Hillwig, Todd C.; Schaub, S. C.; Bond, Howard E.

We explore the photometrically variable central stars of the planetary nebulae HaTr 4 and Hf 2-2. Both have been classified as close binary star systems previously based on their light curves alone. Here, we present additional arguments and data confirming the identification of both as close binaries with an irradiated cool companion to the hot central star. We include updated light curves, orbital periods, and preliminary binary modeling for both systems. We also identify for the first time the central star of HaTr 4 as an eclipsing binary. Neither system has been well studied in the past, but we utilizemore » the small amount of existing data to limit possible binary parameters, including system inclination. These parameters are then compared to nebular parameters to further our knowledge of the relationship between binary central stars of planetary nebulae and nebular shaping and ejection.« less

Identification of TNIP1 Polymorphisms by High Resolution Melting Analysis with Unlabelled Probe: Association with Systemic Lupus Erythematosus

PubMed Central

Zhang, Jie; Chen, Yuewen; Shao, Yong; Wu, Qi; Guan, Ming; Zhang, Wei; Wan, Jun; Yu, Bo

2012-01-01

Background. TNFα-induced protein 3 (TNFAIP3) interacting with protein 1 (TNIP1) acts as a negative regulator of NF-κB and plays an important role in maintaining the homeostasis of immune system. A recent genome-wide association study (GWAS) showed that the polymorphism of TNIP1 was associated with the disease risk of SLE in Caucasian. In this study, we investigated whether the association of TNIP1 with SLE was replicated in Chinese population. Methods. The association of TNIP1 SNP rs7708392 (G/C) was determined by high resolution melting (HRM) analysis with unlabeled probe in 285 SLE patients and 336 healthy controls. Results. A new SNP rs79937737 located on 5 bp upstream of rs7708392 was discovered during the HRM analysis. No association of rs7708392 or rs79937737 with the disease risk of SLE was found. Furthermore, rs7708392 and rs79937737 were in weak linkage disequilibrium (LD). Hypotypes analysis of the two SNPs also showed no association with SLE in Chinese population. Conclusions. High resolution melting analysis with unlabeled probes proves to be a powerful and efficient genotyping method for identifying and screening SNPs. No association of rs7708392 or rs79937737 with the disease risk of SLE was observed in Chinese population. PMID:22852072

Metabotropic glutamate receptors in auditory processing

PubMed Central

Lu, Yong

2014-01-01

As the major excitatory neurotransmitter used in the vertebrate brain, glutamate activates ionotropic and metabotropic glutamate receptors (mGluRs), which mediate fast and slow neuronal actions, respectively. Important modulatory roles of mGluRs have been shown in many brain areas, and drugs targeting mGluRs have been developed for treatment of brain disorders. Here, I review the studies on mGluRs in the auditory system. Anatomical expression of mGluRs in the cochlear nucleus has been well characterized, while data for other auditory nuclei await more systematic investigations at both the light and electron microscopy levels. The physiology of mGluRs has been extensively studied using in vitro brain slice preparations, with a focus on the lower auditory brainstem in both mammals and birds. These in vitro physiological studies have revealed that mGluRs participate in neurotransmission, regulate ionic homeostasis, induce synaptic plasticity, and maintain the balance between excitation and inhibition in a variety of auditory structures. However, very few in vivo physiological studies on mGluRs in auditory processing have been undertaken at the systems level. Many questions regarding the essential roles of mGluRs in auditory processing still remain unanswered and more rigorous basic research is warranted. PMID:24909898

Freight advanced traveler information system : functional requirements.

DOT National Transportation Integrated Search

2012-08-01

This report describes the System Requirement Specifications (SyRS) for a Freight Advanced Traveler Information System (FRATIS). The SyRS is based on user needs described in the FRATIS Concept of Operations (ConOps), which cover the essential function...

Single nucleotide polymorphisms in the Trx2/TXNIP and TrxR2 genes of the mitochondrial thioredoxin antioxidant system and the risk of diabetic retinopathy in patients with Type 2 diabetes mellitus.

PubMed

Ramus, Sara Mankoc; Cilensek, Ines; Petrovic, Mojca Globocnik; Soucek, Miroslav; Kruzliak, Peter; Petrovic, Daniel

2016-03-01

Oxidative stress plays an important role in the pathogenesis of diabetes and its complications. The aim of this study was to examine the possible association between seven single nucleotide polymorphisms (SNPs) of the Trx2/TXNIP and TrxR2 genes encoding proteins involved in the thioredoxin antioxidant defence system and the risk of diabetic retinopthy (DR). Cross-sectional case-control study. A total of 802 Slovenian patients with Type 2 diabetes mellitus; 277 patients with DR and 525 with no DR were enrolled. Patients genotypes of the SNPs; including rs8140110, rs7211, rs7212, rs4755, rs1548357, rs4485648 and rs5748469 were determined by the competitive allele specific PCR method. Each genotype of examined SNPs was regressed in a logistic model, assuming the co-dominant, dominant and the recessive models of inheritance with covariates of duration of diabetes, HbA1c, insulin therapy, total cholesterol and LDL cholesterol levels. In the present study, for the first time we identified an association between the rs4485648 polymorphism of the TrxR2 gene and DR in Caucasians with Type 2 DM. The estimated ORs of adjusted logistic regression models were found to be as follows: 4.4 for CT heterozygotes, 4.3 for TT homozygotes (co-dominant genetic model) and 4.4 for CT+TT genotypes (dominant genetic model). In our case-control study we were not able to demonstrate any association between rs8140110, rs7211, rs7212, rs4755, rs1548357, and rs5748469 and DR, however, our findings provide evidence that the rs4485648 polymorphism of the TrxR2 gene might exert an independent effect on the development of DR. Copyright © 2016 Elsevier Inc. All rights reserved.

Dynamical evolution of young binaries and multiple systems

NASA Astrophysics Data System (ADS)

Reipurth, B.

Most stars, and perhaps all, are born in small multiple systems whose components interact, leading to chaotic dynamic behavior. Some components are ejected, either into distant orbits or into outright escapes, while the remaining components form temporary and eventually permanent binary systems. More than half of all such breakups of multiple systems occur during the protostellar phase, leading to the occasional ejection of protostars outside their nascent cloud cores. Such orphaned protostars are observed as wide companions to embedded protostars, and thus allow the direct study of protostellar objects. Dynamic interactions during early stellar evolution explain the shape and enormous width of the separation distribution function of binaries, from close spectroscopic binaries to the widest binaries.

The ColRS signal transduction system responds to the excess of external zinc, iron, manganese, and cadmium

PubMed Central

2014-01-01

Background The ColRS two-component system has been shown to contribute to the membrane functionality and stress tolerance of Pseudomonas putida as well as to the virulence of Pseudomonas aeruginosa and plant pathogenic Xanthomonas species. However, the conditions activating the ColRS pathway and the signal(s) sensed by ColS have remained unknown. Here we aimed to analyze the role of the ColRS system in metal tolerance of P. putida and to test whether ColS can respond to metal excess. Results We show that the ColRS system is necessary for P. putida to tolerate the excess of iron and zinc, and that it also contributes to manganese and cadmium tolerance. Excess of iron, zinc, manganese or cadmium activates ColRS signaling and as a result modifies the expression of ColR-regulated genes. Our data suggest that the genes in the ColR regulon are functionally redundant, as several loci have to be deleted to observe a significant decrease in metal tolerance. Site-directed mutagenesis of ColS revealed that excess of iron and, surprisingly, also zinc are sensed by a conserved ExxE motif in ColS’s periplasmic domain. While ColS is able to sense different metals, it still discriminates between the two oxidation states of iron, specifically responding to ferric and not ferrous iron. We propose a signal perception model involving a dimeric ColS, where each monomer donates one ExxE motif for metal binding. Conclusions Several transition metals are essential for living organisms in certain amounts, but toxic in excess. We show that ColRS is a sensor system which detects and responds to the excess of physiologically important metals such as zinc, iron and manganese. Thus, the ColRS system is an important factor for metal homeostasis and tolerance in P. putida. PMID:24946800

Evolution of starspots in the long-period RS CVN binary V1817 Cygni = HR 7428

NASA Technical Reports Server (NTRS)

Hall, Douglas S.; Gessner, Susan E.; Lines, Helen C.; Lines, Richard D.

1990-01-01

Photometry between 1982 and 1989, published and unpublished, is analyzed. The ellipticity effect produces variability with a full amplitude of 0.033 m in V. A recent time of light minimum (JD 2445988.0 + or - 0.3 d) combined with an old spectroscopic time of conjunction from the 1920's yields a much improved orbital period (108.854 + or - 0.003). Removal of the ellipticity effect reveals starspot variability. Four different spots were observed at various times, two of them present simultaneously in the light curve during 1985. Mean spot lifetimes were around 2 years and the largest amplitude attributed to starspots was 0.04 m in V during 1986. Derived rotation periods for two spots were 5.3 + or - 1.2 percent slower than synchronous and 3.0 + or - 0.4 percent faster. The differential rotation coefficient for the K2 giant is k = 0.25 + or - 0.04, compared to k = 0.186 for the sun. V1817 Cygni has the longest orbital period of any binary known to execute synchronous rotation.

Photometric Analysis and Modeling of Five Mass-Transferring Binary Systems

NASA Astrophysics Data System (ADS)

Geist, Emily; Beaky, Matthew; Jamison, Kate

2018-01-01

In overcontact eclipsing binary systems, both stellar components have overfilled their Roche lobes, resulting in a dumbbell-shaped shared envelope. Mass transfer is common in overcontact binaries, which can be observed as a slow change on the rotation period of the system.We studied five overcontact eclipsing binary systems with evidence of period change, and thus likely mass transfer between the components, identified by Nelson (2014): V0579 Lyr, KN Vul, V0406 Lyr, V2240 Cyg, and MS Her. We used the 31-inch NURO telescope at Lowell Observatory in Flagstaff, Arizona to obtain images in B,V,R, and I filters for V0579 Lyr, and the 16-inch Meade LX200GPS telescope with attached SBIG ST-8XME CCD camera at Juniata College in Huntingdon, Pennsylvania to image KN Vul, V0406 Lyr, V2240 Cyg, and MS Her, also in B,V,R, and I.After data reduction, we created light curves for each of the systems and modeled the eclipsing binaries using the BinaryMaker3 and PHOEBE programs to determine their fundamental physical parameters for the first time. Complete light curves and preliminary models for each of these neglected eclipsing binary systems will be presented.

Non-invasive diagnostic system and its opto-mechanical probe for combining confocal Raman spectroscopy and optical coherence tomography.

PubMed

Klemes, Jan; Kotzianova, Adela; Pokorny, Marek; Mojzes, Peter; Novak, Jindrich; Sukova, Lada; Demuth, Jaroslav; Vesely, Jaroslav; Sasek, Ladislav; Velebny, Vladimir

2017-11-01

Non-invasive optical diagnostic methods allow important information about studied systems to be obtained in a non-destructive way. Complete diagnosis requires information about the chemical composition as well as the morphological structure of a sample. We report on the development of an opto-mechanical probe that combines Raman spectroscopy (RS) and optical coherence tomography (OCT), two methods that provide all the crucial information needed for a non-invasive diagnosis. The aim of this paper is to introduce the technical design, construction and optimization of a dual opto-mechanical probe combining two in-house developed devices for confocal RS and OCT. The unique benefit of the probe is a gradual acquisition of OCT and RS data, which allows to use the acquired OCT images to pinpoint locations of interest for RS measurements. The parameters and the correct functioning of the probe were verified by RS scanning of various samples (silicon wafer and ex vivo tissue) based on their OCT images - lateral as well as depth scanning was performed. Both the OCT and RS systems were developed, optimized and tested with the ultimate aim of verifying the functionality of the probe. Picture: Schematic illustration and visualization of the developed RS-OCT probe. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

What we learn from eclipsing binaries in the ultraviolet

NASA Technical Reports Server (NTRS)

Guinan, Edward F.

1990-01-01

Recent results on stars and stellar physics from IUE (International Ultraviolet Explorer) observations of eclipsing binaries are discussed. Several case studies are presented, including V 444 Cyg, Aur stars, V 471 Tau and AR Lac. Topics include stellar winds and mass loss, stellar atmospheres, stellar dynamos, and surface activity. Studies of binary star dynamics and evolution are discussed. The progress made with IUE in understanding the complex dynamical and evolutionary processes taking place in W UMa-type binaries and Algol systems is highlighted. The initial results of intensive studies of the W UMa star VW Cep and three representative Algol-type binaries (in different stages of evolution) focused on gas flows and accretion, are included. The future prospects of eclipsing binary research are explored. Remaining problems are surveyed and the next challenges are presented. The roles that eclipsing binaries could play in studies of stellar evolution, cluster dynamics, galactic structure, mass luminosity relations for extra galactic systems, cosmology, and even possible detection of extra solar system planets using eclipsing binaries are discussed.

Relationship between genetic polymorphisms in the DRD5 gene and paranoid schizophrenia in northern Han Chinese.

PubMed

Zhao, Y; Ding, M; Pang, H; Xu, X M; Wang, B J

2014-03-12

Dopamine (DA) has been implicated in the pathophysiol-ogy of several psychiatric disorders, including schizophrenia. Thus, genes related to the dopaminergic (DAergic) system are good candidate genes for schizophrenia. One of receptors of the DA receptor system is dopa-mine receptor 5 (DRD5). Single nucleotide polymorphisms (SNPs) in the regulatory regions of DRD5 gene may affect gene expression, influence biosynthesis of DA and underlie various neuropsychiatric disorders re-lated to DA dysfunction. The present study explored the association of SNPs within the DRD5 gene with paranoid schizophrenia in Han Chinese. A total of 176 patients with schizophrenia and 206 healthy controls were genotyped for four DRD5 SNPs (rs77434921, rs2076907, rs6283, and rs1800762). Significant group differences were observed in the allele and genotype frequencies of rs77434921 and rs1800762 and in the frequen-cies of GC haplotypes corresponding to rs77434921-rs1800762. Our find-ings suggest that common genetic variations of DRD5 are likely to con-tribute to genetic susceptibility to paranoid schizophrenia in Han Chinese. Further studies in larger samples are needed to replicate this association.

Vasopressin V1a receptors are present in the carotid body and contribute to the control of breathing in male Sprague-Dawley rats.

PubMed

Żera, Tymoteusz; Przybylski, Jacek; Grygorowicz, Tomasz; Kasarełło, Kaja; Podobińska, Martyna; Mirowska-Guzel, Dagmara; Cudnoch-Jędrzejewska, Agnieszka

2018-04-01

Vasopressin (AVP) maintains body homeostasis by regulating water balance, cardiovascular system and stress response. AVP inhibits breathing through central vasopressin 1a receptors (V1aRs). Chemoreceptors within carotid bodies (CBs) detect chemical and hormonal signals in the bloodstream and provide sensory input to respiratory and cardiovascular centers of the brainstem. In the study we investigated if CBs contain V1aRs and how the receptors are involved in the regulation of ventilation by AVP. We first immunostained CBs for V1aRs and tyrosine hydroxylase, a marker of chemoreceptor type I (glomus) cells. In urethane-anesthetized adult Sprague-Dawley male rats, we then measured hemodynamic and respiratory responses to systemic (intravenous) or local (carotid artery) administration of AVP prior and after systemic blockade of V1aRs. Immunostaining of CBs showed colocalization of V1aRs and tyrosine hydroxylase within glomus cells. Systemic administration of AVP increased mean arterial blood pressure (MABP) and decreased respiratory rate (RR) and minute ventilation (MV). Local administration of AVP increased MV and RR without significant changes in MABP or heart rate. Pretreatment with V1aR antagonist abolished responses to local and intravenous AVP administration. Our findings show that chemosensory cells within CBs express V1aRs and that local stimulation of the CB with AVP increases ventilation, which is contrary to systemic effects of AVP manifested by decreased ventilation. The responses are mediated by V1aRs, as blockade of the receptors prevents changes in ventilation. We hypothesize that excitatory effects of AVP within the CB provide a counterbalancing mechanism for the inhibitory effects of systemically acting AVP on the respiration. Copyright © 2018 Elsevier Inc. All rights reserved.

Searches for all types of binary mergers in the first Advanced LIGO observing run

NASA Astrophysics Data System (ADS)

Read, Jocelyn

2017-01-01

The first observational run of the Advanced LIGO detectors covered September 12, 2015 to January 19, 2016. In that time, two definitive observations of merging binary black hole systems were made. In particular, the second observation, GW151226, relied on matched-filter searches targeting merging binaries. These searches were also capable of detecting binary mergers from binary neutron stars and from black-hole/neutron-star binaries. In this talk, I will give an overview of LIGO compact binary coalescence searches, in particular focusing on systems that contain neutron stars. I will discuss the sensitive volumes of the first observing run, the astrophysical implications of detections and non-detections, and prospects for future observations

Binary Plutinos

NASA Astrophysics Data System (ADS)

Noll, Keith S.

2015-08-01

The Pluto-Charon binary was the first trans-neptunian binary to be identified in 1978. Pluto-Charon is a true binary with both components orbiting a barycenter located between them. The Pluto system is also the first, and to date only, known binary with a satellite system consisting of four small satellites in near-resonant orbits around the common center of mass. Seven other Plutinos, objects in 3:2 mean motion resonance with Neptune, have orbital companions including 2004 KB19 reported here for the first time. Compared to the Cold Classical population, the Plutinos differ in the frequency of binaries, the relative sizes of the components, and their inclination distribution. These differences point to distinct dynamical histories and binary formation processes encountered by Plutinos.

Another look at AM Herculis - radio-astrometric campaign with the e-EVN at 6 cm

NASA Astrophysics Data System (ADS)

Gawroński, M. P.; Goździewski, K.; Katarzyński, K.; Rycyk, G.

2018-03-01

We conducted radio-interferometric observations of the well-known binary cataclysmic system AM Herculis. This particular system is formed from a magnetic white dwarf (primary) and a red dwarf (secondary), and it is the prototype of so-called polars. Our observations were conducted with the European VLBI Network (EVN) in e-EVN mode at 5 GHz. We obtained six astrometric measurements spanning 1 yr, which make it possible to update the annual parallax for this system with the best precision to date (π = 11.29 ± 0.08 mas), which is equivalent to a distance of 88.6 ± 0.6 pc. The system was observed mostly in the quiescent phase (visual magnitude mv ˜ 15.3), when the radio emission was at the level of about 300 μJy. Our analysis suggests that the radio flux of AM Herculis is modulated with the orbital motion. Such specific properties of the radiation can be explained using an emission mechanism like the scenario proposed for V471 Tau and, in general, for RS CVn-type stars. In this scenario, the radio emission arises near the surface of the red dwarf, where the global magnetic field strength may reach a few kG. We argue that the quiescent radio emission distinguishes AM Herculis and AR Ursae Majoris (a second known persistent radio polar) from other polars, which are systems with a magnetized secondary star.

Life and light: exotic photosynthesis in binary and multiple-star systems.

PubMed

O'Malley-James, J T; Raven, J A; Cockell, C S; Greaves, J S

2012-02-01

The potential for Earth-like planets within binary/multiple-star systems to host photosynthetic life was evaluated by modeling the levels of photosynthetically active radiation (PAR) such planets receive. Combinations of M and G stars in (i) close-binary systems; (ii) wide-binary systems, and (iii) three-star systems were investigated, and a range of stable radiation environments were found to be possible. These environmental conditions allow for the possibility of familiar, but also more exotic, forms of photosynthetic life, such as IR photosynthesizers and organisms that are specialized for specific spectral niches.

High Resolution Imaging of Very Low Mass Spectral Binaries: Three Resolved Systems and Detection of Orbital Motion in an L/T Transition Binary

NASA Astrophysics Data System (ADS)

Bardalez Gagliuffi, Daniella C.; Gelino, Christopher R.; Burgasser, Adam J.

2015-11-01

We present high resolution Laser Guide Star Adaptive Optics imaging of 43 late-M, L and T dwarf systems with Keck/NIRC2. These include 17 spectral binary candidates, systems whose spectra suggest the presence of a T dwarf secondary. We resolve three systems: 2MASS J1341-3052, SDSS J1511+0607 and SDSS J2052-1609 the first two are resolved for the first time. All three have projected separations <8 AU and estimated periods of 14-80 years. We also report a preliminary orbit determination for SDSS J2052-1609 based on six epochs of resolved astrometry between 2005 and 2010. Among the 14 unresolved spectral binaries, 5 systems were confirmed binaries but remained unresolved, implying a minimum binary fraction of {47}-11+12% for this sample. Our inability to resolve most of the spectral binaries, including the confirmed binaries, supports the hypothesis that a large fraction of very low mass systems have relatively small separations and are missed with direct imaging. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

Equilibrium, stability, and orbital evolution of close binary systems

NASA Technical Reports Server (NTRS)

Lai, Dong; Rasio, Frederic A.; Shapiro, Stuart L.

1994-01-01

We present a new analytic study of the equilibrium and stability properties of close binary systems containing polytropic components. Our method is based on the use of ellipsoidal trial functions in an energy variational principle. We consider both synchronized and nonsynchronized systems, constructing the compressible generalizations of the classical Darwin and Darwin-Riemann configurations. Our method can be applied to a wide variety of binary models where the stellar masses, radii, spins, entropies, and polytropic indices are all allowed to vary over wide ranges and independently for each component. We find that both secular and dynamical instabilities can develop before a Roche limit or contact is reached along a sequence of models with decreasing binary separation. High incompressibility always makes a given binary system more susceptible to these instabilities, but the dependence on the mass ratio is more complicated. As simple applications, we construct models of double degenerate systems and of low-mass main-sequence star binaries. We also discuss the orbital evoltuion of close binary systems under the combined influence of fluid viscosity and secular angular momentum losses from processes like gravitational radiation. We show that the existence of global fluid instabilities can have a profound effect on the terminal evolution of coalescing binaries. The validity of our analytic solutions is examined by means of detailed comparisons with the results of recent numerical fluid calculations in three dimensions.

Genetic variation in the oxytocin receptor (OXTR) gene is associated with Asperger Syndrome.

PubMed

Di Napoli, Agnese; Warrier, Varun; Baron-Cohen, Simon; Chakrabarti, Bhismadev

2014-01-01

Autism Spectrum Conditions (ASC) are a group of neurodevelopmental conditions characterized by impairments in communication and social interaction, alongside unusually repetitive behaviors and narrow interests. ASC are highly heritable and have complex patterns of inheritance where multiple genes are involved, alongside environmental and epigenetic factors. Asperger Syndrome (AS) is a subgroup of these conditions, where there is no history of language or cognitive delay. Animal models suggest a role for oxytocin (OXT) and oxytocin receptor (OXTR) genes in social-emotional behaviors, and several studies indicate that the oxytocin/oxytocin receptor system is altered in individuals with ASC. Previous studies have reported associations between genetic variations in the OXTR gene and ASC. The present study tested for an association between nine single nucleotide polymorphisms (SNPs) in the OXTR gene and AS in 530 individuals of Caucasian origin, using SNP association test and haplotype analysis. There was a significant association between rs2268493 in OXTR and AS. Multiple haplotypes that include this SNP (rs2268493-rs2254298, rs2268490-rs2268493-rs2254298, rs2268493-rs2254298-rs53576, rs237885-rs2268490-rs2268493-rs2254298, rs2268490-rs2268493-rs2254298-rs53576) were also associated with AS. rs2268493 has been previously associated with ASC and putatively alters several transcription factor-binding sites and regulates chromatin states, either directly or through other variants in linkage disequilibrium (LD). This study reports a significant association of the sequence variant rs2268493 in the OXTR gene and associated haplotypes with AS.

LISA verification binaries with updated distances from Gaia Data Release 2

NASA Astrophysics Data System (ADS)

Kupfer, T.; Korol, V.; Shah, S.; Nelemans, G.; Marsh, T. R.; Ramsay, G.; Groot, P. J.; Steeghs, D. T. H.; Rossi, E. M.

2018-06-01

Ultracompact binaries with orbital periods less than a few hours will dominate the gravitational wave signal in the mHz regime. Until recently, 10 systems were expected have a predicted gravitational wave signal strong enough to be detectable by the Laser Interferometer Space Antenna (LISA), the so-called `verification binaries'. System parameters, including distances, are needed to provide an accurate prediction of the expected gravitational wave strength to be measured by LISA. Using parallaxes from Gaia Data Release 2 we calculate signal-to-noise ratios (SNR) for ≈50 verification binary candidates. We find that 11 binaries reach a SNR≥20, two further binaries reaching a SNR≥5 and three more systems are expected to have a SNR≈5 after four years integration with LISA. For these 16 systems we present predictions of the gravitational wave amplitude (A) and parameter uncertainties from Fisher information matrix on the amplitude (A) and inclination (ι).

Planet Formation in Binary Star Systems

NASA Astrophysics Data System (ADS)

Martin, Rebecca

About half of observed exoplanets are estimated to be in binary systems. Understanding planet formation and evolution in binaries is therefore essential for explaining observed exoplanet properties. Recently, we discovered that a highly misaligned circumstellar disk in a binary system can undergo global Kozai-Lidov (KL) oscillations of the disk inclination and eccentricity. These oscillations likely have a significant impact on the formation and orbital evolution of planets in binary star systems. Planet formation by core accretion cannot operate during KL oscillations of the disk. First, we propose to consider the process of disk mass transfer between the binary members. Secondly, we will investigate the possibility of planet formation by disk fragmentation. Disk self gravity can weaken or suppress the oscillations during the early disk evolution when the disk mass is relatively high for a narrow range of parameters. Thirdly, we will investigate the evolution of a planet whose orbit is initially aligned with respect to the disk, but misaligned with respect to the orbit of the binary. We will study how these processes relate to observations of star-spin and planet orbit misalignment and to observations of planets that appear to be undergoing KL oscillations. Finally, we will analyze the evolution of misaligned multi-planet systems. This theoretical work will involve a combination of analytic and numerical techniques. The aim of this research is to shed some light on the formation of planets in binary star systems and to contribute to NASA's goal of understanding of the origins of exoplanetary systems.

Realization of Massive Relativistic Spin- 3 / 2 Rarita-Schwinger Quasiparticle in Condensed Matter Systems

NASA Astrophysics Data System (ADS)

Tang, Feng; Luo, Xi; Du, Yongping; Yu, Yue; Wan, Xiangang

Very recently, there has been significant progress in realizing high-energy particles in condensed matter system (CMS) such as the Dirac, Weyl and Majorana fermions. Besides the spin-1/2 particles, the spin-3/2 elementary particle, known as the Rarita-Schwinger (RS) fermion, has not been observed or simulated in the laboratory. The main obstacle of realizing RS fermion in CMS lies in the nontrivial constraints that eliminate the redundant degrees of freedom in its representation of the Poincaré group. In this Letter, we propose a generic method that automatically contains the constraints in the Hamiltonian and prove the RS modes always exist and can be separated from the other non-RS bands. Through symmetry considerations, we show that the two dimensional (2D) massive RS (M-RS) quasiparticle can emerge in several trigonal and hexagonal lattices. Based on ab initio calculations, we predict that the thin film of CaLiX (X=Ge and Si) may host 2D M-RS excitations near the Fermi level. and Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China.

Polar alignment of a protoplanetary disc around an eccentric binary II: Effect of binary and disc parameters

NASA Astrophysics Data System (ADS)

Martin, Rebecca G.; Lubow, Stephen H.

2018-06-01

In a recent paper Martin & Lubow showed that a circumbinary disc around an eccentric binary can undergo damped nodal oscillations that lead to the polar (perpendicular) alignment of the disc relative to the binary orbit. The disc angular momentum vector aligns to the eccentricity vector of the binary. We explore the robustness of this mechanism for a low mass disc (0.001 of the binary mass) and its dependence on system parameters by means of hydrodynamic disc simulations. We describe how the evolution depends upon the disc viscosity, temperature, size, binary mass ratio, orbital eccentricity and inclination. We compare results with predictions of linear theory. We show that polar alignment of a low mass disc may occur over a wide range of binary-disc parameters. We discuss the application of our results to the formation of planetary systems around eccentric binary stars.

RED GIANTS IN ECLIPSING BINARY AND MULTIPLE-STAR SYSTEMS: MODELING AND ASTEROSEISMIC ANALYSIS OF 70 CANDIDATES FROM KEPLER DATA

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

Gaulme, P.; McKeever, J.; Rawls, M. L.

2013-04-10

Red giant stars are proving to be an incredible source of information for testing models of stellar evolution, as asteroseismology has opened up a window into their interiors. Such insights are a direct result of the unprecedented data from space missions CoRoT and Kepler as well as recent theoretical advances. Eclipsing binaries are also fundamental astrophysical objects, and when coupled with asteroseismology, binaries provide two independent methods to obtain masses and radii and exciting opportunities to develop highly constrained stellar models. The possibility of discovering pulsating red giants in eclipsing binary systems is therefore an important goal that could potentiallymore » offer very robust characterization of these systems. Until recently, only one case has been discovered with Kepler. We cross-correlate the detected red giant and eclipsing-binary catalogs from Kepler data to find possible candidate systems. Light-curve modeling and mean properties measured from asteroseismology are combined to yield specific measurements of periods, masses, radii, temperatures, eclipse timing variations, core rotation rates, and red giant evolutionary state. After using three different techniques to eliminate false positives, out of the 70 systems common to the red giant and eclipsing-binary catalogs we find 13 strong candidates (12 previously unknown) to be eclipsing binaries, one to be a non-eclipsing binary with tidally induced oscillations, and 10 more to be hierarchical triple systems, all of which include a pulsating red giant. The systems span a range of orbital eccentricities, periods, and spectral types F, G, K, and M for the companion of the red giant. One case even suggests an eclipsing binary composed of two red giant stars and another of a red giant with a {delta}-Scuti star. The discovery of multiple pulsating red giants in eclipsing binaries provides an exciting test bed for precise astrophysical modeling, and follow-up spectroscopic observations of many of the candidate systems are encouraged. The resulting highly constrained stellar parameters will allow, for example, the exploration of how binary tidal interactions affect pulsations when compared to the single-star case.« less

Association study of functional polymorphisms in interleukins and interleukin receptors genes: IL1A, IL1B, IL1RN, IL6, IL6R, IL10, IL10RA and TGFB1 in schizophrenia in Polish population.

PubMed

Kapelski, Pawel; Skibinska, Maria; Maciukiewicz, Malgorzata; Wilkosc, Monika; Frydecka, Dorota; Groszewska, Agata; Narozna, Beata; Dmitrzak-Weglarz, Monika; Czerski, Piotr; Pawlak, Joanna; Rajewska-Rager, Aleksandra; Leszczynska-Rodziewicz, Anna; Slopien, Agnieszka; Zaremba, Dorota; Twarowska-Hauser, Joanna

2015-12-01

Schizophrenia has been associated with a large range of autoimmune diseases, with a history of any autoimmune disease being associated with a 45% increase in risk for the illness. The inflammatory system may trigger or modulate the course of schizophrenia through complex mechanisms influencing neurodevelopment, neuroplasticity and neurotransmission. In particular, increases or imbalance in cytokine before birth or during the early stages of life may affect neurodevelopment and produce vulnerability to the disease. A total of 27 polymorphisms of IL1N gene: rs1800587, rs17561; IL1B gene: rs1143634, rs1143643, rs16944, rs4848306, rs1143623, rs1143633, rs1143627; IL1RN gene: rs419598, rs315952, rs9005, rs4251961; IL6 gene: rs1800795, rs1800797; IL6R gene: rs4537545, rs4845617, rs2228145, IL10 gene: rs1800896, rs1800871, rs1800872, rs1800890, rs6676671; IL10RA gene: rs2229113, rs3135932; TGF1B gene: rs1800469, rs1800470; each selected on the basis of molecular evidence for functionality, were investigated in this study. Analysis was performed on a group of 621 patients with diagnosis of schizophrenia and 531 healthy controls in Polish population. An association of rs4848306 in IL1B gene, rs4251961 in IL1RN gene, rs2228145 and rs4537545 in IL6R with schizophrenia have been observed. rs6676671 in IL10 was associated with early age of onset. Strong linkage disequilibrium was observed between analyzed polymorphisms in each gene, except of IL10RA. We observed that haplotypes composed of rs4537545 and rs2228145 in IL6R gene were associated with schizophrenia. Analyses with family history of schizophrenia, other psychiatric disorders and alcohol abuse/dependence did not show any positive findings. Further studies on larger groups along with correlation with circulating protein levels are needed. Copyright © 2015 Elsevier B.V. All rights reserved.

From wide to close binaries?

NASA Astrophysics Data System (ADS)

Eggleton, Peter P.

The mechanisms by which the periods of wide binaries (mass 8 solar mass or less and period 10-3000 d) are lengthened or shortened are discussed, synthesizing the results of recent theoretical investigations. A system of nomenclature involving seven evolutionary states, three geometrical states, and 10 types of orbital-period evolution is developed and applied; classifications of 71 binaries are presented in a table along with the basic observational parameters. Evolutionary processes in wide binaries (single-star-type winds, magnetic braking with tidal friction, and companion-reinforced attrition), late case B systems, low-mass X-ray binaries, and triple systems are examined in detail, and possible evolutionary paths are shown in diagrams.

Investigation of Flood Risk Assessment in Inaccessible Regions using Multiple Remote Sensing and Geographic Information Systems

NASA Astrophysics Data System (ADS)

Lim, J.; Lee, K. S.

2017-12-01

Flooding is extremely dangerous when a river overflows to inundate an urban area. From 1995 to 2016, North Korea (NK) experienced annual extensive damage to life and property almost each year due to a levee breach resulting from typhoons and heavy rainfall during the summer monsoon season. Recently, Hoeryeong City (2016) experienced heavy rainfall during typhoon Lionrock and the resulting flood killed and injured many people (68,900) and destroyed numerous buildings and settlements (11,600). The NK state media described it as the biggest national disaster since 1945. Thus, almost all annual repeat occurrences of floods in NK have had a serious impact, which makes it necessary to figure out the extent of floods in restoring the damaged environment. In addition, traditional hydrological model is impractical to delineate Flood Damaged Areas (FDAs) in NK due to the inaccessibility. Under such a situation, multiple optical Remote Sensing (RS) and radar RS along with a Geographic Information System (GIS)-based spatial analysis were utilized in this study (1) to develop modelling FDA delineation using multiple RS and GIS methods and (2) to conduct flood risk assessment in NK. Interpreting high-resolution web-based satellite imagery were also implemented to confirm the results of the study. From the study result, it was found that (1) on August 30th, 2016, an area of 117.2 km2 (8.6%) at Hoeryeong City was inundated. Most floods occurred in flat areas with a lower and middle stream order. (2) In the binary logistic regression model applied in this study, the distance from the nearest stream map and landform map variables are important factors to delineate FDAs because these two factors reflect heterogeneous mountainous NK topography. (3) Total annual flood risk of study area is estimated to be ₩454.13 million NKW ($504,417.24 USD, and ₩576.53 million SKW). The risk of the confluence of the Tumen River and Hoeryeong stream appears to be the highest. (4) High resolution satellite images can be used to confirm study results as ground truth data in this study, which shows the possibility of further application in environmental research of NK. Ultimately, this study provides recommendations to improve flood risk management in NK upon reunification.

Formation of black hole x-ray binaries in globular clusters

NASA Astrophysics Data System (ADS)

Kremer, Kyle; Chatterjee, Sourav; Rodriguez, Carl; Rasio, Frederic

2018-01-01

We explore the formation of mass-transferring binary systems containing black holes within globular clusters. We show that it is possible to form mass-transferring binaries with main sequence, giant, and white dwarf companions with a variety of orbital parameters in globular clusters spanning a large range in present-day properties. We show that the presence of mass-transferring black hole systems has little correlation with the total number of black holes within the cluster at any time. In addition to mass-transferring binaries retained within their host clusters at late times, we also examine the black hole and neutron star binaries that are ejected from their host clusters. These ejected systems may contribute to the low-mass x-ray binary population in the galactic field.

Experimental research and comparison of LDPC and RS channel coding in ultraviolet communication systems.

PubMed

Wu, Menglong; Han, Dahai; Zhang, Xiang; Zhang, Feng; Zhang, Min; Yue, Guangxin

2014-03-10

We have implemented a modified Low-Density Parity-Check (LDPC) codec algorithm in ultraviolet (UV) communication system. Simulations are conducted with measured parameters to evaluate the LDPC-based UV system performance. Moreover, LDPC (960, 480) and RS (18, 10) are implemented and experimented via a non-line-of-sight (NLOS) UV test bed. The experimental results are in agreement with the simulation and suggest that based on the given power and 10(-3)bit error rate (BER), in comparison with an uncoded system, average communication distance increases 32% with RS code, while 78% with LDPC code.

Slotting optimization of automated storage and retrieval system (AS/RS) for efficient delivery of parts in an assembly shop using genetic algorithm: A case Study

NASA Astrophysics Data System (ADS)

Yue, L.; Guan, Z.; He, C.; Luo, D.; Saif, U.

2017-06-01

In recent years, the competitive pressure on manufacturing companies shifted them from mass production to mass customization to produce large variety of products. It is a great challenge for companies nowadays to produce customized mixed flow mode of production to meet customized demand on time. Due to large variety of products, the storage system to deliver variety of products to production lines influences on the timely production of variety of products, as investigated from by simulation study of an inefficient storage system of a real Company, in the current research. Therefore, current research proposed a slotting optimization model with mixed model sequence to assemble in consideration of the final flow lines to optimize whole automated storage and retrieval system (AS/RS) and distribution system in the case company. Current research is aimed to minimize vertical height of centre of gravity of AS/RS and total time spent for taking the materials out from the AS/RS simultaneously. Genetic algorithm is adopted to solve the proposed problem and computational result shows significant improvement in stability and efficiency of AS/RS as compared to the existing method used in the case company.

Dielectric properties of grain-grainboundary binary system

NASA Astrophysics Data System (ADS)

Cheng, Peng-Fei; Li, Sheng-Tao; Wang, Hui

2014-09-01

Dielectric properties of grain-grainboundary binary system are analyzed theoretically and compared with unary system and classical Maxwell-Wagner (MW) polarization in binary system. It is found that MW polarization appears at higher frequency compared with intrinsic polarization for grain-grainboundary binary system, which is abnormal compared with classical dielectric theory. This dielectric anomaly is premised on the existence of electronic relaxation at grainboundary. The origin of giant dielectric constant of CaCu3Ti4O12 (CCTO) ceramics is also investigated on the basis of the theoretical results. It is proposed that low frequency relaxation originates from electronic relaxation of oxygen vacancy at depletion layer, while high frequency relaxation comes from MW polarization. The results of this paper offer a quantitative identification of MW polarization from intrinsic polarization at grainboundary and a judgment of the mechanism and location of a certain polarization in grain-grainboundary binary system.

Clock gene modulates roles of OXTR and AVPR1b genes in prosociality.

PubMed

Ci, Haipeng; Wu, Nan; Su, Yanjie

2014-01-01

The arginine vasopressin receptor (AVPR) and oxytocin receptor (OXTR) genes have been demonstrated to contribute to prosocial behavior. Recent research has focused on the manner by which these simple receptor genes influence prosociality, particularly with regard to the AVP system, which is modulated by the clock gene. The clock gene is responsible for regulating the human biological clock, affecting sleep, emotion and behavior. The current study examined in detail whether the influences of the OXTR and AVPR1b genes on prosociality are dependent on the clock gene. This study assessed interactions between the clock gene (rs1801260, rs6832769) and the OXTR (rs1042778, rs237887) and AVPR1b (rs28373064) genes in association with individual differences in prosociality in healthy male Chinese subjects (n = 436). The Prosocial Tendencies Measure (PTM-R) was used to assess prosociality. Participants carrying both the GG/GA variant of AVPR1b rs28373064 and the AA variant of clock rs6832769 showed the highest scores on the Emotional PTM. Carriers of both the T allele of OXTR rs1042778 and the C allele of clock rs1801260 showed the lowest total PTM scores compared with the other groups. The observed interaction effects provide converging evidence that the clock gene and OXT/AVP systems are intertwined and contribute to human prosociality.

Role of Fatty Acid Kinase in Cellular Lipid Homeostasis and SaeRS-Dependent Virulence Factor Expression in Staphylococcus aureus.

PubMed

Ericson, Megan E; Subramanian, Chitra; Frank, Matthew W; Rock, Charles O

2017-08-01

The SaeRS two-component system is a master activator of virulence factor transcription in Staphylococcus aureus , but the cellular factors that control its activity are unknown. Fatty acid (FA) kinase is a two-component enzyme system required for extracellular FA uptake and SaeRS activity. Here, we demonstrate the existence of an intracellular nonesterified FA pool in S. aureus that is elevated in strains lacking FA kinase activity. SaeRS-mediated transcription is restored in FA kinase-negative strains when the intracellular FA pool is reduced either by growth with FA-depleted bovine serum albumin to extract the FA into the medium or by the heterologous expression of Neisseria gonorrhoeae acyl-acyl carrier protein synthetase to activate FA for phospholipid synthesis. These data show that FAs act as negative regulators of SaeRS signaling, and FA kinase activates SaeRS-dependent virulence factor production by lowering inhibitory FA levels. Thus, FA kinase plays a role in cellular lipid homeostasis by activating FA for incorporation into phospholipid, and it indirectly regulates SaeRS signaling by maintaining a low intracellular FA pool. IMPORTANCE The SaeRS two-component system is a master transcriptional activator of virulence factor production in response to the host environment in S. aureus , and strains lacking FA kinase have severely attenuated SaeRS-dependent virulence factor transcription. FA kinase is required for the activation of exogenous FAs, and it plays a role in cellular lipid homeostasis by recycling cellular FAs into the phospholipid biosynthetic pathway. Activation of the sensor kinase, SaeS, is mediated by its membrane anchor domain, and the FAs which accumulate in FA kinase knockout strains are potent inhibitors of SaeS-dependent signaling. This work identifies FAs as physiological effectors for the SaeRS system and reveals a connection between cellular lipid homeostasis and the regulation of virulence factor transcription. FA kinase is widely distributed in Gram-positive bacteria, suggesting similar roles for FA kinase in these organisms. Copyright © 2017 Ericson et al.

WIYN OPEN CLUSTER STUDY. XXXVI. SPECTROSCOPIC BINARY ORBITS IN NGC 188

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

Geller, Aaron M.; Mathieu, Robert D.; Harris, Hugh C.

2009-04-15

We present 98 spectroscopic binary orbits resulting from our ongoing radial velocity survey of the old (7 Gyr) open cluster NGC 188. All but 13 are high-probability cluster members based on both radial velocity and proper motion membership analyses. Fifteen of these member binaries are double lined. Our stellar sample spans a magnitude range of 10.8 {<=}V{<=} 16.5 (1.14-0.92 M {sub sun}) and extends spatially to 17 pc ({approx}13 core radii). All of our binary orbits have periods ranging from a few days to on the order of 10{sup 3} days, and thus are hard binaries that dynamically power themore » cluster. For each binary, we present the orbital solutions and place constraints on the component masses. Additionally, we discuss a few binaries of note from our sample, identifying a likely blue straggler-blue straggler binary system (7782), a double-lined binary with a secondary star which is underluminous for its mass (5080), two potential eclipsing binaries (4705 and 5762), and two binaries which are likely members of a quadruple system (5015a and 5015b)« less

Modeling the binary circumstellar medium of Type IIb/L/n supernova progenitors

NASA Astrophysics Data System (ADS)

Kolb, Christopher; Blondin, John; Borkowski, Kazik; Reynolds, Stephen

2018-01-01

Circumstellar interaction in close binary systems can produce a highly asymmetric environment, particularly for systems with a mass outflow velocity comparable to the binary orbital speed. This asymmetric circumstellar medium (CSM) becomes visible after a supernova explosion, when SN radiation illuminates the gas and when SN ejecta collide with the CSM. We aim to better understand the development of this asymmetric CSM, particularly for binary systems containing a red supergiant progenitor, and to study its impact on supernova morphology. To achieve this, we model the asymmetric wind and subsequent supernova explosion in full 3D hydrodynamics using the shock-capturing hydro code VH-1 on a spherical yin-yang grid. Wind interaction is computed in a frame co-rotating with the binary system, and gas is accelerated using a radiation pressure-driven wind model where optical depth of the radiative force is dependent on azimuthally-averaged gas density. We present characterization of our asymmetric wind density distribution model by fitting a polar-to-equatorial density contrast function to free parameters such as binary separation distance, primary mass loss rate, and binary mass ratio.

KOI-3278: a self-lensing binary star system.

PubMed

Kruse, Ethan; Agol, Eric

2014-04-18

Over 40% of Sun-like stars are bound in binary or multistar systems. Stellar remnants in edge-on binary systems can gravitationally magnify their companions, as predicted 40 years ago. By using data from the Kepler spacecraft, we report the detection of such a "self-lensing" system, in which a 5-hour pulse of 0.1% amplitude occurs every orbital period. The white dwarf stellar remnant and its Sun-like companion orbit one another every 88.18 days, a long period for a white dwarf-eclipsing binary. By modeling the pulse as gravitational magnification (microlensing) along with Kepler's laws and stellar models, we constrain the mass of the white dwarf to be ~63% of the mass of our Sun. Further study of this system, and any others discovered like it, will help to constrain the physics of white dwarfs and binary star evolution.

Gravitational radiation, inspiraling binaries, and cosmology

NASA Technical Reports Server (NTRS)

Chernoff, David F.; Finn, Lee S.

1993-01-01

We show how to measure cosmological parameters using observations of inspiraling binary neutron star or black hole systems in one or more gravitational wave detectors. To illustrate, we focus on the case of fixed mass binary systems observed in a single Laser Interferometer Gravitational-wave Observatory (LIGO)-like detector. Using realistic detector noise estimates, we characterize the rate of detections as a function of a threshold SNR Rho(0), H0, and the binary 'chirp' mass. For Rho(0) = 8, H0 = 100 km/s/Mpc, and 1.4 solar mass neutron star binaries, the sample has a median redshift of 0.22. Under the same assumptions but independent of H0, a conservative rate density of coalescing binaries implies LIGO will observe about 50/yr binary inspiral events. The precision with which H0 and the deceleration parameter q0 may be determined depends on the number of observed inspirals. For fixed mass binary systems, about 100 observations with Rho(0) = 10 in the LIGO will give H0 to 10 percent in an Einstein-DeSitter cosmology, and 3000 will give q0 to 20 percent. For the conservative rate density of coalescing binaries, 100 detections with Rho(0) = 10 will require about 4 yrs.

A New Orbit for the Eclipsing Binary V577 Oph

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

Jeffery, Elizabeth J.; Barnes, Thomas G. III; Montemayor, Thomas J.

Pulsating stars in eclipsing binary systems are unique objects for providing constraints on stellar models. To fully leverage the information available from the binary system, full orbital radial velocity curves must be obtained. We report 23 radial velocities for components of the eclipsing binary V577 Oph, whose primary star is a δ Sct variable. The velocities cover a nearly complete orbit and a time base of 20 years. We computed orbital elements for the binary and compared them to the ephemeris computed by Creevey et al. The comparison shows marginally different results. In particular, a change in the systemic velocitymore » by −2 km s{sup −1} is suggested by our results. We compare this systemic velocity difference to that expected due to reflex motion of the binary in response to the third body in the system. The systemic velocity difference is consistent with reflex motion, given our mass determination for the eclipsing binary and the orbital parameters determined by Volkov and Volkova for the three-body orbit. We see no evidence for the third body in our spectra, but we do see strong interstellar Na D lines that are consistent in strength with the direction and expected distance of V577 Oph.« less

VfrB Is a Key Activator of the Staphylococcus aureus SaeRS Two-Component System.

PubMed

Krute, Christina N; Rice, Kelly C; Bose, Jeffrey L

2017-03-01

In previous studies, we identified the fatty acid kinase virulence factor regulator B (VfrB) as a potent regulator of α-hemolysin and other virulence factors in Staphylococcus aureus In this study, we demonstrated that VfrB is a positive activator of the SaeRS two-component regulatory system. Analysis of vfrB , saeR , and saeS mutant strains revealed that VfrB functions in the same pathway as SaeRS. At the transcriptional level, the promoter activities of SaeRS class I ( coa ) and class II ( hla ) target genes were downregulated during the exponential growth phase in the vfrB mutant, compared to the wild-type strain. In addition, saePQRS expression was decreased in the vfrB mutant strain, demonstrating a need for this protein in the autoregulation of SaeRS. The requirement for VfrB-mediated activation was circumvented when SaeS was constitutively active due to an SaeS (L18P) substitution. Furthermore, activation of SaeS via human neutrophil peptide 1 (HNP-1) overcame the dependence on VfrB for transcription from class I Sae promoters. Consistent with the role of VfrB in fatty acid metabolism, hla expression was decreased in the vfrB mutant with the addition of exogenous myristic acid. Lastly, we determined that aspartic acid residues D38 and D40, which are predicted to be key to VfrB enzymatic activity, were required for VfrB-mediated α-hemolysin production. Collectively, this study implicates VfrB as a novel accessory protein needed for the activation of SaeRS in S. aureus IMPORTANCE The SaeRS two-component system is a key regulator of virulence determinant production in Staphylococcus aureus Although the regulon of this two-component system is well characterized, the activation mechanisms, including the specific signaling molecules, remain elusive. Elucidating the complex regulatory circuit of SaeRS regulation is important for understanding how the system contributes to disease causation by this pathogen. To this end, we have identified the fatty acid kinase VfrB as a positive regulatory modulator of SaeRS-mediated transcription of virulence factors in S. aureus In addition to describing a new regulatory aspect of SaeRS, this study establishes a link between fatty acid kinase activity and virulence factor regulation. Copyright © 2017 American Society for Microbiology.

Testing a new engine controller system for the RS-25

NASA Image and Video Library

2017-07-25

Engineers conduct the third in a series of RS-25 flight controller tests on July 25, 2017, for NASA’s Space Launch System (SLS) rocket. The more than 8 1/2 minute test on the A-1 Test Stand at NASA’s Stennis Space Center in Mississippi signaled another step toward launch of NASA’s new Space Launch System (SLS). The SLS rocket, powered by four RS-25 engines, along with the Orion spacecraft will take astronauts on a new era of exploration beyond Earth’s orbit into deep space.

Doubled-lined eclipsing binary system KIC~2306740 with pulsating component discovered from Kepler space photometry

NASA Astrophysics Data System (ADS)

Yakut, Kadri

2015-08-01

We present a detailed study of KIC 2306740, an eccentric double-lined eclipsing binary system with a pulsating component.Archive Kepler satellite data were combined with newly obtained spectroscopic data with 4.2\\,m William Herschel Telescope(WHT). This allowed us to determine rather precise orbital and physical parameters of this long period, slightly eccentric, pulsating binary system. Duplicity effects are extracted from the light curve in order to estimate pulsation frequencies from the residuals.We modelled the detached binary system assuming non-conservative evolution models with the Cambridge STARS(TWIN) code.

Formation of wide binaries by turbulent fragmentation

NASA Astrophysics Data System (ADS)

Lee, Jeong-Eun; Lee, Seokho; Dunham, Michael M.; Tatematsu, Ken'ichi; Choi, Minho; Bergin, Edwin A.; Evans, Neal J.

2017-08-01

Understanding the formation of wide-binary systems of very low-mass stars (M ≤ 0.1 solar masses, M⊙) is challenging 1,2,3 . The most obvious route is through widely separated low-mass collapsing fragments produced by turbulent fragmentation of a molecular core4,5. However, close binaries or multiples from disk fragmentation can also evolve to wide binaries over a few initial crossing times of the stellar cluster through tidal evolution6. Finding an isolated low-mass wide-binary system in the earliest stage of formation, before tidal evolution could occur, would prove that turbulent fragmentation is a viable mechanism for (very) low-mass wide binaries. Here we report high-resolution ALMA observations of a known wide-separation protostellar binary, showing that each component has a circumstellar disk. The system is too young7 to have evolved from a close binary, and the disk axes are misaligned, providing strong support for the turbulent fragmentation model. Masses of both stars are derived from the Keplerian rotation of the disks; both are very low-mass stars.

Anisotropic distribution of orbit poles of binary asteroids

NASA Astrophysics Data System (ADS)

Pravec, P.; Scheirich, P.; Vokrouhlický, D.; Harris, A. W.; Kusnirak, P.; Hornoch, K.; Pray, D. P.; Higgins, D.; Galád, A.; Világi, J.; Gajdos, S.; Kornos, L.; Oey, J.; Husárik, M.; Cooney, W. R.; Gross, J.; Terrell, D.; Durkee, R.; Pollock, J.; Reichart, D.; Ivarsen, K.; Haislip, J.; Lacluyze, A.; Krugly, Y. N.; Gaftonyuk, N.; Dyvig, R.; Reddy, V.; Stephens, R. D.; Chiorny, V.; Vaduvescu, O.; Longa, P.; Tudorica, A.; Warner, B. D.; Masi, G.; Brinsfield, J.; Gonçalves, R.; Brown, P.; Krzeminski, Z.; Gerashchenko, O.; Marchis, F.

2011-10-01

Our photometric observations of 18 mainbelt binary systems in more than one apparition revealed a strikingly high number of 15 having positively re-observed mutual events in the return apparitions. Our simulations of the survey showed that the data strongly suggest that poles of mutual orbits between components of binary asteroids are not distributed randomly: The null hypothesis of the isotropic distribution of orbit poles is rejected at a confidence level greater than 99.99%. Binary orbit poles concentrate at high ecliptic latitudes, within 30° of the poles of the ecliptic. We propose that the binary orbit poles oriented preferentially up/down-right are due to formation of small binary systems by rotational fission of critically spinning parent bodies with poles near the YORP asymptotic states with obliquities near 0 and 180°. An alternative process of elimination of binaries with poles closer to the ecliptic by the Kozai dynamics of gravitational perturbations from the sun does not explain the observed orbit pole concentration as in the close asteroid binary systems the J2 perturbation due to the primary dominates the solar-tide effect.

A comparative study using WHO and binary oral epithelial dysplasia grading systems in actinic cheilitis.

PubMed

Câmara, P R; Dutra, S N; Takahama Júnior, A; Fontes, Kbfc; Azevedo, R S

2016-09-01

To evaluate comparatively the influence of histopathological features on epithelial dysplasia (ED) and the effectiveness in usage of WHO and binary grading systems in actinic cheilitis (AC). Cytological and architectural alterations established by WHO for ED were evaluated in 107 cases of AC. Epithelial dysplasia was graded using WHO and binary systems. The comparisons were performed using kappa, chi-square, and phi coefficient tests (P < 0.05). Most cases were classified as mild ED (44.5%) in the WHO system and as low risk for malignant transformation (64.5%) in the binary system. There was a positive correlation between WHO and binary systems (k = 0.33; P < 0.0002). Loss of basal cell polarity (P < 0.001) was associated with severity of ED grade in the WHO system. Anisonucleosis (P < 0.0001), nuclear pleomorphism (P < 0.0001), anisocytosis (P = 0.03), cell pleomorphism (P = 0.002) increased nuclear/cytoplasm ratio (P < 0.0001), increased nuclear size (P < 0.0001), increased number of mitotic figures (P = 0.0006), and dyskeratosis (P = 0.008) were associated with severity of ED grade in the binary system. It seems that usage of binary ED grading system in AC may be more precise because there is correlation between many of cytological and some of architectural microscopic alterations with increased grade of ED. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Terrestrial Planet Formation Around Close Binary Stars

NASA Technical Reports Server (NTRS)

Lissauer, Jack J.; Quintana, Elisa V.

2003-01-01

Most stars reside in multiple star systems; however, virtually all models of planetary growth have assumed an isolated single star. Numerical simulations of the collapse of molecular cloud cores to form binary stars suggest that disks will form within such systems. Observations indirectly suggest disk material around one or both components within young binary star systems. If planets form at the right places within such circumstellar disks, they can remain in stable orbits within the binary star systems for eons. We are simulating the late stages of growth of terrestrial planets around close binary stars, using a new, ultrafast, symplectic integrator that we have developed for this purpose. The sum of the masses of the two stars is one solar mass, and the initial disk of planetary embryos is the same as that used for simulating the late stages of terrestrial planet growth within our Solar System and in the Alpha Centauri wide binary star system. Giant planets &are included in the simulations, as they are in most simulations of the late stages of terrestrial planet accumulation in our Solar System. When the stars travel on a circular orbit with semimajor axis of up to 0.1 AU about their mutual center of mass, the planetary embryos grow into a system of terrestrial planets that is statistically identical to those formed about single stars, but a larger semimajor axis and/or a significantly eccentric binary orbit can lead to significantly more dynamically hot terrestrial planet systems.

Association between rs2431697 T allele on 5q33.3 and systemic lupus erythematosus: case-control study and meta-analysis.

PubMed

Tang, Zhao-Ming; Wang, Ping; Chang, Pan-Pan; Hasahya, Tony; Xing, Hui; Wang, Jin-Ping; Hu, Li-Hua

2015-11-01

rs2431697 is located on 5q33.3, between pituitary tumor-transforming gene 1 and miR-146a. Several studies have estimated the association between rs2431697 and systemic lupus erythematosus risk. However, the results were inconsistent. A case-control study was carried out to explore the association between rs2431697 and systemic lupus erythematosus risk in a central Chinese population. Meta-analyses combining present with previous studies were conducted to further explore the association. Our case-control study included 322 cases and 353 controls. rs2431697 T allele was associated with increased risk of systemic lupus erythematosus (odds ratios (ORs) = 1.461, 95% confidence intervals (CI) 1.091-1.957, P = 0.011). The association was stronger between T allele and the risk of anti-double-stranded DNA (dsDNA)-positive systemic lupus erythematosus (OR = 2.510, 95% CI 1.545-4.077, P < 0.001). The meta-analyses included 8648 systemic lupus erythematosus patients and 10947 controls. rs2431697 T allele had an overall OR of 1.262 (95% CI 1.205-1.323, P < 0.001) under fixed-effects model. After stratified by ethnicity, I (2) reduced from 24.3 to 0 %. T allele had an OR of 1.213 (95% CI 1.145-1.284, P < 0.001) in European descendant and 1.365 (95% CI 1.259-1.480, P < 0.001) in Asian under fixed-effects model. Data on women were also extracted, and T allele had an OR of 1.337 (95% CI 1.162-1.539, P < 0.001) under random-effects model. The pooled ORs were not influenced by each study in sensitivity analyses. There were no publication biases observed in these analyses. The results from our case-control study and the meta-analyses indicate that rs2431697 T allele significantly associates with the increased risk of systemic lupus erythematosus.

SHAPING THE BROWN DWARF DESERT: PREDICTING THE PRIMORDIAL BROWN DWARF BINARY DISTRIBUTIONS FROM TURBULENT FRAGMENTATION

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

Jumper, Peter H.; Fisher, Robert T., E-mail: robert.fisher@umassd.edu

2013-05-20

The formation of brown dwarfs (BDs) poses a key challenge to star formation theory. The observed dearth of nearby ({<=}5 AU) BD companions to solar mass stars, known as the BD desert, as well as the tendency for low-mass binary systems to be more tightly bound than stellar binaries, has been cited as evidence for distinct formation mechanisms for BDs and stars. In this paper, we explore the implications of the minimal hypothesis that BDs in binary systems originate via the same fundamental fragmentation mechanism as stars, within isolated, turbulent giant molecular cloud cores. We demonstrate analytically that the scalingmore » of specific angular momentum with turbulent core mass naturally gives rise to the BD desert, as well as wide BD binary systems. Further, we show that the turbulent core fragmentation model also naturally predicts that very low mass binary and BD/BD systems are more tightly bound than stellar systems. In addition, in order to capture the stochastic variation intrinsic to turbulence, we generate 10{sup 4} model turbulent cores with synthetic turbulent velocity fields to show that the turbulent fragmentation model accommodates a small fraction of binary BDs with wide separations, similar to observations. Indeed, the picture which emerges from the turbulent fragmentation model is that a single fragmentation mechanism may largely shape both stellar and BD binary distributions during formation.« less

Genetic Variants of TPCN2 Associated with Type 2 Diabetes Risk in the Chinese Population

PubMed Central

Zhang, Yu; Fan, Xiaofang; Zhang, Ning; Zheng, Hui; Song, Yuping; Shen, Chunfang; Shen, Jiayi; Ren, Fengdong; Yang, Jialin

2016-01-01

Objective The aim of this study was to determine whether TPCN2 genetic variants are associated with type 2 diabetes and to elucidate which variants in TPCN2 confer diabetes susceptibility in the Chinese population. Research Design and Methods The sample population included 384 patients with type 2 diabetes and 1468 controls. Anthropometric parameters, glycemic and lipid profiles and insulin resistance were measured. We selected 6 TPCN2 tag single nucleotide polymorphisms (rs35264875, rs267603153, rs267603154, rs3829241, rs1551305, and rs3750965). Genotypes were determined using a Sequenom MassARRAY SNP genotyping system. Results Ultimately, we genotyped 3 single nucleotide polymorphisms (rs3750965, rs3829241, and rs1551305) in all individuals. There was a 5.1% higher prevalence of the rs1551305 variant allele in type 2 diabetes individuals (A) compared with wild-type homozygous individuals (G). The AA genotype of rs1551305 was associated with a higher diabetes risk (p<0.05). The distributions of rs3829241 and rs3750965 polymorphisms were not significantly different between the two groups. HOMA-%B of subjects harboring the AA genotype of rs1551305 decreased by 14.87% relative to the GG genotype. Conclusions TPCN2 plays a role in metabolic regulation, and the rs1551305 single nucleotide polymorphism is associated with type 2 diabetes risk. Future work will begin to unravel the underlying mechanisms. PMID:26918892

Genetic variants of CD209 associated with Kawasaki disease susceptibility.

PubMed

Kuo, Ho-Chang; Huang, Ying-Hsien; Chien, Shu-Chen; Yu, Hong-Ren; Hsieh, Kai-Sheng; Hsu, Yu-Wen; Chang, Wei-Chiao

2014-01-01

Kawasaki disease (KD) is a systemic vasculitis with unknown etiology mainly affecting children in Asian countries. Dendritic cell-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN, CD209) in humans was showed to trigger an anti-inflammatory cascade and associated with KD susceptibility. This study was conducted to investigate the association between genetic polymorphisms of CD209 and the risk KD. A total of 948 subjects (381 KD and 567 controls) were recruited. Nine tagging SNPs (rs8112310, rs4804800, rs11465421, rs1544766, rs4804801, rs2287886, rs735239, rs735240, rs4804804) were selected for TaqMan allelic discrimination assay. Clinical phenotypes, coronary artery lesions (CAL) and intravenous immunoglobulin (IVIG) treatment outcomes were collected for analysis. Significant associations were found between CD209 polymorphisms (rs4804800, rs2287886, rs735240) and the risk of KD. Haplotype analysis for CD209 polymorphisms showed that A/A/G haplotype (P = 0.0002, OR = 1.61) and G/A/G haplotype (P = 0.0365, OR = 1.52) had higher risk of KD as compared with G/G/A haplotype in rs2287886/rs735239/rs735240 pairwise allele analysis. There were no significant association in KD with regards to CAL formation and IVIG treatment responses. CD209 polymorphisms were responsible for the susceptibility of KD, but not CAL formation and IVIG treatment responsiveness.

Genetic Variants of CD209 Associated with Kawasaki Disease Susceptibility

PubMed Central

Kuo, Ho-Chang; Huang, Ying-Hsien; Chien, Shu-Chen; Yu, Hong-Ren; Hsieh, Kai-Sheng; Hsu, Yu-Wen; Chang, Wei-Chiao

2014-01-01

Background Kawasaki disease (KD) is a systemic vasculitis with unknown etiology mainly affecting children in Asian countries. Dendritic cell-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN, CD209) in humans was showed to trigger an anti-inflammatory cascade and associated with KD susceptibility. This study was conducted to investigate the association between genetic polymorphisms of CD209 and the risk KD. Methods A total of 948 subjects (381 KD and 567 controls) were recruited. Nine tagging SNPs (rs8112310, rs4804800, rs11465421, rs1544766, rs4804801, rs2287886, rs735239, rs735240, rs4804804) were selected for TaqMan allelic discrimination assay. Clinical phenotypes, coronary artery lesions (CAL) and intravenous immunoglobulin (IVIG) treatment outcomes were collected for analysis. Results Significant associations were found between CD209 polymorphisms (rs4804800, rs2287886, rs735240) and the risk of KD. Haplotype analysis for CD209 polymorphisms showed that A/A/G haplotype (P = 0.0002, OR = 1.61) and G/A/G haplotype (P = 0.0365, OR = 1.52) had higher risk of KD as compared with G/G/A haplotype in rs2287886/rs735239/rs735240 pairwise allele analysis. There were no significant association in KD with regards to CAL formation and IVIG treatment responses. Conclusion CD209 polymorphisms were responsible for the susceptibility of KD, but not CAL formation and IVIG treatment responsiveness. PMID:25148534

Genetic dissection of host immune response in pneumonia development and progression.

PubMed

Smelaya, Tamara V; Belopolskaya, Olesya B; Smirnova, Svetlana V; Kuzovlev, Artem N; Moroz, Viktor V; Golubev, Arkadiy M; Pabalan, Noel A; Salnikova, Lyubov E

2016-10-11

The role of host genetic variation in pneumonia development and outcome is poorly understood. We studied common polymorphisms in the genes of proinflammatory cytokines (IL6 rs1800795, IL8 rs4073, IL1B rs16944), anti-inflammatory cytokines (IL10 rs1800896, IL4 rs2243250, IL13 rs20541) and toll-like receptors (TLR2 rs5743708 and rs4696480, TLR4 rs4986791, TLR9 rs352139, rs5743836 and rs187084) in patients with community-acquired pneumonia (CAP) (390 cases, 203 controls) and nosocomial pneumonia (355 cases, 216 controls). Experimental data were included in a series of 11 meta-analyses and eight subset analyses related to pneumonia susceptibility and outcome. TLR2 rs5743708 minor genotype appeared to be associated with CAP/Legionnaires' disease/pneumococcal disease. In CAP patients, the IL6 rs1800795-C allele was associated with severe sepsis/septic shock/severe systemic inflammatory response, while the IL10 rs1800896-A allele protected against the development of these critical conditions. To contribute to deciphering of the above results, we performed an in silico analysis and a qualitative synthesis of literature data addressing basal and stimulated genotype-specific expression level. This data together with database information on transcription factors' affinity changes caused by SNPs in putative promoter regions, the results of linkage disequilibrium analysis along with SNPs functional annotations supported assumptions about the complexity underlying the revealed associations.

Are Binary Separations related to their System Mass?

NASA Astrophysics Data System (ADS)

Sterzik, M. F.; Durisen, R. H.

2004-08-01

We compile most recent multiplicity fractions and binary separation distributions for different primary masses, including very low-mass and brown dwarf primaries, and compare them with dynamical decay models of small-N clusters. The model predictions are based on detailed numerical calculations of the internal cluster dynamics, as well as on Monte-Carlo methods. Both observations and models reflect the same trends: (1) The multiplicity fraction is an increasing function of the primary mass. (2) The mean binary separations are increasing with the system mass in the sense that very low-mass binaries have average separations around ≈ 4AU, while the binary separation distribution for solar-type primaries peaks at ≈ 40AU. M-type binary systems apparently preferentially populate intermediate separations. Similar specific energy at the time of cluster formation for all cluster masses can possibly explain this trend.

Interferon Regulatory Factor 5 Gene Polymorphisms in Iranian Women with Unexplained Recurrent Pregnancy Loss.

PubMed

Amiri Jahromi, Rakhshan; Nasiri, Mahboobeh; Jahromi, Athar Rasekh

2017-01-01

This study aimed to examine the association of three functional IRF5 rs10954213, rs3757385, and rs41298401 polymorphisms with susceptibility to unexplained recurrent pregnancy loss (RPL) among Iranian women from south of Iran. 176 women with unexplained RPL and 173 healthy postmenopausal controls were enrolled in this case-control study. Genotyping of the polymorphisms rs10954213 and rs3757385 was carried out using touchdown tetra-primer amplification refractory mutation system-polymerase chain reaction (T-ARMS PCR), and polymorphism rs41298401 was typed using PCR-restriction fragment length polymorphism (PCR-RFLP). Genotype frequencies were significantly different between RPL cases and controls regarding AG heterozygote genotype of rs10954213, GT genotype of rs3757385, and GG genotype of rs41298401. In addition, allele variants (G for rs10954213, T for rs3757385, and G for rs41298401) showed protective role against RPL, while GG haplotype of two first variants was shown to be a susceptibility factor for the disease. These data provide the first evidence, to our knowledge, of the protective role of the studied IRF5 gene polymorphisms against unexplained RPL among Iranian women from south of Iran.

Stochastic Gravitational-Wave Background due to Primordial Binary Black Hole Mergers.

PubMed

Mandic, Vuk; Bird, Simeon; Cholis, Ilias

2016-11-11

Recent Advanced LIGO detections of binary black hole mergers have prompted multiple studies investigating the possibility that the heavy GW150914 binary system was of primordial origin, and hence could be evidence for dark matter in the form of black holes. We compute the stochastic background arising from the incoherent superposition of such primordial binary black hole systems in the Universe and compare it to the similar background spectrum due to binary black hole systems of stellar origin. We investigate the possibility of detecting this background with future gravitational-wave detectors, and conclude that constraining the dark matter component in the form of black holes using stochastic gravitational-wave background measurements will be very challenging.

Planetary nebula progenitors that swallow binary systems

NASA Astrophysics Data System (ADS)

Soker, Noam

2016-01-01

I propose that some irregular messy planetary nebulae (PNe) owe their morphologies to triple-stellar evolution where tight binary systems evolve inside and/or on the outskirts of the envelope of asymptotic giant branch (AGB) stars. In some cases, the tight binary system can survive, in others, it is destroyed. The tight binary system might break up with one star leaving the system. In an alternative evolution, one of the stars of the broken-up tight binary system falls towards the AGB envelope with low specific angular momentum, and drowns in the envelope. In a different type of destruction process, the drag inside the AGB envelope causes the tight binary system to merge. This releases gravitational energy within the AGB envelope, leading to a very asymmetrical envelope ejection, with an irregular and messy PN as a descendant. The evolution of the triple-stellar system can be in a full common envelope evolution or in a grazing envelope evolution. Both before and after destruction (if destruction takes place), the system might launch pairs of opposite jets. One pronounced signature of triple-stellar evolution might be a large departure from axisymmetrical morphology of the descendant PN. I estimate that about one in eight non-spherical PNe is shaped by one of these triple-stellar evolutionary routes.

Late type close binary system CM Dra

NASA Astrophysics Data System (ADS)

Kalomeni, Belinda

2015-08-01

In this study, we present new observations of the close binary system CM Dra. We analyzed all the available data of the system and estimated the physical parameters of the system stars highly accurately. Using the newly obtained parameters the distance of the system is determined to be 11.6 pc. A possible giant planet orbiting the close binary system has been detected. This orbital period would likely make it one of the longest known orbital period planet.

An inherent-optical-property-centered approach to correct the angular effects in water-leaving radiance.

PubMed

Lee, Zhong Ping; Du, Keping; Voss, Kenneth J; Zibordi, Giuseppe; Lubac, Bertrand; Arnone, Robert; Weidemann, Alan

2011-07-01

Remote-sensing reflectance (R(rs)), which is defined as the ratio of water-leaving radiance (L(w)) to downwelling irradiance just above the surface (E(d)(0⁺)), varies with both water constituents (including bottom properties of optically-shallow waters) and angular geometry. L(w) is commonly measured in the field or by satellite sensors at convenient angles, while E(d)(0⁺) can be measured in the field or estimated based on atmospheric properties. To isolate the variations of R(rs) (or L(w)) resulting from a change of water constituents, the angular effects of R(rs) (or L(w)) need to be removed. This is also a necessity for the calibration and validation of satellite ocean color measurements. To reach this objective, for optically-deep waters where bottom contribution is negligible, we present a system centered on water's inherent optical properties (IOPs). It can be used to derive IOPs from angular R_rs and offers an alternative to the system centered on the concentration of chlorophyll. This system is applicable to oceanic and coastal waters as well as to multiband and hyperspectral sensors. This IOP-centered system is applied to both numerically simulated data and in situ measurements to test and evaluate its performance. The good results obtained suggest that the system can be applied to angular R(rs) to retrieve IOPs and to remove the angular variation of R(rs).

RNA-Dependent Cysteine Biosynthesis in Bacteria and Archaea

DOE PAGES

Mukai, Takahito; Crnković, Ana; Umehara, Takuya; ...

2017-05-09

ABSTRACT The diversity of the genetic code systems used by microbes on earth is yet to be elucidated. It is known that certain methanogenic archaea employ an alternative system for cysteine (Cys) biosynthesis and encoding; tRNA Cysis first acylated with phosphoserine (Sep) byO-phosphoseryl-tRNA synthetase (SepRS) and then converted to Cys-tRNA Cysby Sep-tRNA:Cys-tRNA synthase (SepCysS). In this study, we searched all genomic and metagenomic protein sequence data in the Integrated Microbial Genomes (IMG) system and at the NCBI to reveal new clades of SepRS and SepCysS proteins belonging to diverse archaea in the four major groups (DPANN,Euryarchaeota, TACK, and Asgard) andmore » two groups of bacteria (“CandidatusParcubacteria” andChloroflexi). Bacterial SepRS and SepCysS charged bacterial tRNA Cysspecies with cysteinein vitro. Homologs of SepCysE, a scaffold protein facilitating SepRS-SepCysS complex assembly in Euryarchaeota class I methanogens, are found in a few groups of TACK and Asgard archaea, whereas the C-terminally truncated homologs exist fused or genetically coupled with diverse SepCysS species. Investigation of the selenocysteine (Sec)- and pyrrolysine (Pyl)-utilizing traits in SepRS-utilizing archaea and bacteria revealed that the archaea carrying full-length SepCysE employ Sec and that SepRS is often found in Pyl-utilizing archaea andChloroflexibacteria. We further discuss possible contributions of the SepRS-SepCysS system for sulfur assimilation, methanogenesis, and other metabolic processes requiring large amounts of iron-sulfur enzymes or Pyl-containing enzymes.« less

RNA-Dependent Cysteine Biosynthesis in Bacteria and Archaea

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

Mukai, Takahito; Crnković, Ana; Umehara, Takuya

ABSTRACT The diversity of the genetic code systems used by microbes on earth is yet to be elucidated. It is known that certain methanogenic archaea employ an alternative system for cysteine (Cys) biosynthesis and encoding; tRNA Cysis first acylated with phosphoserine (Sep) byO-phosphoseryl-tRNA synthetase (SepRS) and then converted to Cys-tRNA Cysby Sep-tRNA:Cys-tRNA synthase (SepCysS). In this study, we searched all genomic and metagenomic protein sequence data in the Integrated Microbial Genomes (IMG) system and at the NCBI to reveal new clades of SepRS and SepCysS proteins belonging to diverse archaea in the four major groups (DPANN,Euryarchaeota, TACK, and Asgard) andmore » two groups of bacteria (“CandidatusParcubacteria” andChloroflexi). Bacterial SepRS and SepCysS charged bacterial tRNA Cysspecies with cysteinein vitro. Homologs of SepCysE, a scaffold protein facilitating SepRS-SepCysS complex assembly in Euryarchaeota class I methanogens, are found in a few groups of TACK and Asgard archaea, whereas the C-terminally truncated homologs exist fused or genetically coupled with diverse SepCysS species. Investigation of the selenocysteine (Sec)- and pyrrolysine (Pyl)-utilizing traits in SepRS-utilizing archaea and bacteria revealed that the archaea carrying full-length SepCysE employ Sec and that SepRS is often found in Pyl-utilizing archaea andChloroflexibacteria. We further discuss possible contributions of the SepRS-SepCysS system for sulfur assimilation, methanogenesis, and other metabolic processes requiring large amounts of iron-sulfur enzymes or Pyl-containing enzymes.« less

Association of TNF-α rs1799964 and IL-1β rs16944 polymorphisms with multiple system atrophy in Chinese Han population.

PubMed

Zhou, Xin; Wang, Chunrong; Chen, Zhao; Peng, Yun; Peng, Huirong; Hou, Xuan; Ye, Wei; Qiu, Rong; Xia, Kun; Tang, Beisha; Jiang, Hong

2018-01-07

Recent evidence suggested that several single nucleotide polymorphisms (SNPs) of inflammation-related genes (TNF-α rs1799964, IL-1α rs1800587, IL-1β rs16944, IL-8 rs4073, ICAM-1 rs5498) were associated with multiple system atrophy (MSA). Herein, we conducted this case-control study to evaluate the possible correlation between the five SNPs related to inflammation and MSA in Chinese Han population. We recruited 154 sporadic patients with MSA and 223 health controls in this study. All subjects were genotyped for the five SNPs using polymerase chain reaction amplification and Sanger sequencing. TNF-α rs1799964, genotype distribution and minor allele frequency (MAF) showed significant differences between patients and controls, which might illustrate the minor allele C may increase the risk for MSA (genotype, P = 0.006, OR = 1.245, 95% CI = [1.066-1.455]; allele, P = 0.001, OR = 1.887, 95% CI = [1.303-2.733]). For rs16944, patients carrying AA genotype showed a nearly 5-year early age at onset (AAO) than GG genotype (50.52 ± 7.45 years vs. 54.90 ± 7.21 years, P = 0.037). No differences were found in genotype distribution and MAF of the five SNPs between patients with MSA with predominant cerebellar ataxia (MSA-C) and with predominant Parkinsonism (MSA-P). Our study suggests that rs1799964 of TNF-α may act as a risk factor for MSA and the IL-1β rs16944 might be a genetic factor that modifies the AAO in MSA. Moreover, the exact mechanism of neuroinflammatory response in MSA deserves further exploration.

Muscarinic Receptors Modulate Dendrodendritic Inhibitory Synapses to Sculpt Glomerular Output

PubMed Central

Shao, Zuoyi; Puche, Adam; Wachowiak, Matt; Rothermel, Markus

2015-01-01

Cholinergic [acetylcholine (ACh)] axons from the basal forebrain innervate olfactory bulb glomeruli, the initial site of synaptic integration in the olfactory system. Both nicotinic acetylcholine receptors (nAChRs) and muscarinic acetylcholine receptors (mAChRs) are expressed in glomeruli. The activation of nAChRs directly excites both mitral/tufted cells (MTCs) and external tufted cells (ETCs), the two major excitatory neurons that transmit glomerular output. The functional roles of mAChRs in glomerular circuits are unknown. We show that the restricted glomerular application of ACh causes rapid, brief nAChR-mediated excitation of both MTCs and ETCs in the mouse olfactory bulb. This excitation is followed by mAChR-mediated inhibition, which is blocked by GABAA receptor antagonists, indicating the engagement of periglomerular cells (PGCs) and/or short axon cells (SACs), the two major glomerular inhibitory neurons. Indeed, selective activation of glomerular mAChRs, with ionotropic GluRs and nAChRs blocked, increased IPSCs in MTCs and ETCs, indicating that mAChRs recruit glomerular inhibitory circuits. Selective activation of glomerular mAChRs in the presence of tetrodotoxin increased IPSCs in all glomerular neurons, indicating action potential-independent enhancement of GABA release from PGC and/or SAC dendrodendritic synapses. mAChR-mediated enhancement of GABA release also presynaptically suppressed the first synapse of the olfactory system via GABAB receptors on sensory terminals. Together, these results indicate that cholinergic modulation of glomerular circuits is biphasic, involving an initial excitation of MTC/ETCs mediated by nAChRs followed by inhibition mediated directly by mAChRs on PGCs/SACs. This may phasically enhance the sensitivity of glomerular outputs to odorants, an action that is consistent with recent in vivo findings. PMID:25855181

Muscarinic receptors modulate dendrodendritic inhibitory synapses to sculpt glomerular output.

PubMed

Liu, Shaolin; Shao, Zuoyi; Puche, Adam; Wachowiak, Matt; Rothermel, Markus; Shipley, Michael T

2015-04-08

Cholinergic [acetylcholine (ACh)] axons from the basal forebrain innervate olfactory bulb glomeruli, the initial site of synaptic integration in the olfactory system. Both nicotinic acetylcholine receptors (nAChRs) and muscarinic acetylcholine receptors (mAChRs) are expressed in glomeruli. The activation of nAChRs directly excites both mitral/tufted cells (MTCs) and external tufted cells (ETCs), the two major excitatory neurons that transmit glomerular output. The functional roles of mAChRs in glomerular circuits are unknown. We show that the restricted glomerular application of ACh causes rapid, brief nAChR-mediated excitation of both MTCs and ETCs in the mouse olfactory bulb. This excitation is followed by mAChR-mediated inhibition, which is blocked by GABAA receptor antagonists, indicating the engagement of periglomerular cells (PGCs) and/or short axon cells (SACs), the two major glomerular inhibitory neurons. Indeed, selective activation of glomerular mAChRs, with ionotropic GluRs and nAChRs blocked, increased IPSCs in MTCs and ETCs, indicating that mAChRs recruit glomerular inhibitory circuits. Selective activation of glomerular mAChRs in the presence of tetrodotoxin increased IPSCs in all glomerular neurons, indicating action potential-independent enhancement of GABA release from PGC and/or SAC dendrodendritic synapses. mAChR-mediated enhancement of GABA release also presynaptically suppressed the first synapse of the olfactory system via GABAB receptors on sensory terminals. Together, these results indicate that cholinergic modulation of glomerular circuits is biphasic, involving an initial excitation of MTC/ETCs mediated by nAChRs followed by inhibition mediated directly by mAChRs on PGCs/SACs. This may phasically enhance the sensitivity of glomerular outputs to odorants, an action that is consistent with recent in vivo findings. Copyright © 2015 the authors 0270-6474/15/355680-13$15.00/0.

NATRIURETIC PEPTIDE SYSTEM GENE VARIANTS ARE ASSOCIATED WITH VENTRICULAR DYSFUNCTION AFTER CORONARY ARTERY BYPASS GRAFTING

PubMed Central

Fox, Amanda A.; Collard, Charles D.; Shernan, Stanton K.; Seidman, Christine E.; Seidman, Jonathan G.; Liu, Kuang-Yu; Muehlschlegel, Jochen D.; Perry, Tjorvi E.; Aranki, Sary F.; Lange, Christoph; Herman, Daniel S.; Meitinger, Thomas; Lichtner, Peter; Body, Simon C.

2009-01-01

Background Ventricular dysfunction (VnD) after primary coronary artery bypass grafting is associated with increased hospital stay and mortality. Natriuretic peptides have compensatory vasodilatory, natriuretic and paracrine influences on myocardial failure and ischemia. We hypothesized that natriuretic peptide system gene variants independently predict risk of VnD after primary coronary artery bypass grafting. Methods 1164 patients undergoing primary coronary artery bypass grafting with cardiopulmonary bypass at two institutions were prospectively enrolled. After prospectively defined exclusions, 697 Caucasian patients (76 with VnD) were analyzed. VnD was defined as need for ≥ 2 new inotropes and/or new mechanical ventricular support after coronary artery bypass grafting. 139 haplotype-tagging SNPs within 7 genes (NPPA; NPPB; NPPC; NPR1; NPR2; NPR3; CORIN) were genotyped. SNPs univariately associated with VnD were entered into logistic regression models adjusting for clinical covariates predictive of VnD. To control for multiple comparisons, permutation analyses were conducted for all SNP associations. Results After adjusting for clinical covariates and multiple comparisons within each gene, seven NPPA/NPPB SNPs (rs632793, rs6668352, rs549596, rs198388, rs198389, rs6676300, rs1009592) were associated with decreased risk of postoperative VnD (additive model; odds ratios 0.44–0.55; P = 0.010–0.036), and four NPR3 SNPs (rs700923, rs16890196, rs765199, rs700926) were associated with increased risk of postoperative VnD (recessive model; odds ratios 3.89–4.28; P = 0.007–0.034). Conclusions Genetic variation within the NPPA/NPPB and NPR3 genes is associated with risk of VnD after primary coronary artery bypass grafting. Knowledge of such genotypic predictors may result in better understanding of the molecular mechanisms underlying postoperative VnD. PMID:19326473

Association between BANK1 polymorphisms and susceptibility to autoimmune diseases: A meta-analysis.

PubMed

Bae, S-C; Lee, Y H

2017-03-31

This study aimed to explore whether BANK1 polymorphisms are associated with susceptibility to autoimmune diseases. We conducted a meta-analysis on the associations between the BANK1 rs10516487, rs3733197, and rs17266594 polymorphisms and autoimmune diseases. Twenty-two articles with a total of 22,684 patients and 36,437 controls were included in the meta-analysis. Meta-analysis revealed a significant association between autoimmune diseases and the BANK1 rs10516487 T allele (OR = 1.161, 95% CI = 1.092-1.275, p = 1.9 × 10-6, heterogeneity p<0.001). The analysis also revealed an association between autoimmune diseases and the BANK1 rs3733197 A allele (OR = 1.178, 95% CI = 1.105-1.256, p = 4.5 × 10-7, heterogeneity p = 0.002) and the rs17266594 T allele (OR = 1.189, 95% CI = 1.073-1.315, p = 0.001, heterogeneity p<0.001). Meta-analysis by autoimmune disease type revealed an association between both systemic lupus erythematosus and systemic sclerosis and the BANK1 rs10516487 T allele (OR = 1.294, 95% CI = 1.232-1.360, p<1.0 × 10-8, heterogeneity p = 0.556; OR = 1.102, 95% CI = 1.027-1.183, p = 0.017, heterogeneity p = 0.048). However, meta-analysis failed to indicate an association between the BANK1 rs10516487 T allele and rheumatoid arthritis (RA; OR = 1.006, 95% CI = 1.956-1.058, p = 0.819). This meta-analysis demonstrates that BANK1 rs10516487, rs3733197, and rs17266594 polymorphisms are associated with susceptibility to autoimmune diseases.

The Staphylococcus aureus ArlRS Two-Component System Is a Novel Regulator of Agglutination and Pathogenesis

PubMed Central

Walker, Jennifer N.; Crosby, Heidi A.; Spaulding, Adam R.; Salgado-Pabón, Wilmara; Malone, Cheryl L.; Rosenthal, Carolyn B.; Schlievert, Patrick M.; Boyd, Jeffrey M.; Horswill, Alexander R.

2013-01-01

Staphylococcus aureus is a prominent bacterial pathogen that is known to agglutinate in the presence of human plasma to form stable clumps. There is increasing evidence that agglutination aids S. aureus pathogenesis, but the mechanisms of this process remain to be fully elucidated. To better define this process, we developed both tube based and flow cytometry methods to monitor clumping in the presence of extracellular matrix proteins. We discovered that the ArlRS two-component system regulates the agglutination mechanism during exposure to human plasma or fibrinogen. Using divergent S. aureus strains, we demonstrated that arlRS mutants are unable to agglutinate, and this phenotype can be complemented. We found that the ebh gene, encoding the Giant Staphylococcal Surface Protein (GSSP), was up-regulated in an arlRS mutant. By introducing an ebh complete deletion into an arlRS mutant, agglutination was restored. To assess whether GSSP is the primary effector, a constitutive promoter was inserted upstream of the ebh gene on the chromosome in a wildtype strain, which prevented clump formation and demonstrated that GSSP has a negative impact on the agglutination mechanism. Due to the parallels of agglutination with infective endocarditis development, we assessed the phenotype of an arlRS mutant in a rabbit combined model of sepsis and endocarditis. In this model the arlRS mutant displayed a large defect in vegetation formation and pathogenesis, and this phenotype was partially restored by removing GSSP. Altogether, we have discovered that the ArlRS system controls a novel mechanism through which S. aureus regulates agglutination and pathogenesis. PMID:24367264

Self-organization in a system of binary strings with spatial interactions

NASA Astrophysics Data System (ADS)

Banzhaf, W.; Dittrich, P.; Eller, B.

1999-01-01

We consider an artificial reaction system whose components are binary strings. Upon encounter, two binary strings produce a third string which competes for storage space with the originators. String types or species can only survive when produced in sufficient numbers. Spatial interactions through introduction of a topology and rules for distance-dependent reactions are discussed. We observe various kinds of survival strategies of binary strings.

The formation of high-mass binary star systems

NASA Astrophysics Data System (ADS)

Lund, Kristin; Bonnell, Ian A.

2018-06-01

We develop a semi-analytic model to investigate how accretion onto wide low-mass binary stars can result in a close high-mass binary system. The key ingredient is to allow mass accretion while limiting the gain in angular momentum. We envision this process as being regulated by an external magnetic field during infall. Molecular clouds are made to collapse spherically with material either accreting onto the stars or settling in a disk. Our aim is to determine what initial conditions are needed for the resulting binary to be both massive and close. Whether material accretes, and what happens to the binary separation as a result, depends on the relative size of its specific angular momentum, compared to the specific angular momentum of the binary. When we add a magnetic field we are introducing a torque to the system which is capable of stripping the molecular cloud of some of its angular momentum, and consequently easing the formation of high-mass binaries. Our results suggest that clouds in excess of 1000 M⊙ and radii of 0.5 pc or larger, can easily form binary systems with masses in excess of 25 M⊙ and separations of order 10 R⊙ with magnetic fields of order 100 μG (mass-to-flux ratios of order 5).

Building an Unusual White-Dwarf Duo

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2016-09-01

A new study has examined how the puzzling wide binary system HS 2220+2146 which consists of two white dwarfs orbiting each other might have formed. This system may be an example of a new evolutionary pathway for wide white-dwarf binaries.Evolution of a BinaryMore than 100 stellar systems have been discovered consisting of two white dwarfs in a wide orbit around each other. How do these binaries form? In the traditional picture, the system begins as a binary consisting of two main-sequence stars. Due to the large separation between the stars, the stars evolve independently, each passing through the main-sequence and giant branches and ending their lives as white dwarfs.An illustration of a hierarchical triple star system, in which two stars orbit each other, and a third star orbits the pair. [NASA/JPL-Caltech]Because more massive stars evolve more quickly, the most massive of the two stars in a binary pair should be the first to evolve into a white dwarf. Consequently, when we observe a double-white-dwarf binary, its usually a safe bet that the more massive of the two white dwarfs will also be the older and cooler of the pair, since it should have formed first.But in the case of the double-white-dwarf binary HS 2220+2146, the opposite is true: the more massive of the two white dwarfs appears to be the younger and hotter of the pair. If it wasnt created in the traditional way, then how did this system form?Two From Three?Led by Jeff Andrews (Foundation for Research and Technology-Hellas, Greece and Columbia University), a team of scientists recently examined this system more carefully, analyzing its spectra to confirm our understanding of the white dwarfs temperatures and masses.Based on their observations, Andrews and collaborators determined that there are no hidden additional companions that could have caused the unusual evolution of this system. Instead, the team proposed that this unusual binary might be an example of an evolutionary channel that involves three stars.The authors proposed formation scenario for H220+2146. In this picture, the inner binary merges to form a blue straggler. This star and the remaining main-sequence star then evolve independently into white dwarfs, forming the system observed today. [Andrews et al. 2016]An Early MergerIn the model the authors propose for HS 2220+2146, the binary system began as a hierarchical triple system of main-sequence stars. The innermost binary then merged to form a large star known as a blue straggler a star that, due to the merger, will evolve more slowly than its larger mass implies it should.The blue straggler and the remaining main-sequence star, still in a wide orbit, then continued to evolve independently of each other. The smaller star ended its main-sequence lifetime and became a white dwarf first, followed by the more massive but slowly evolving blue straggler thus forming the system we observe today.If the authors model is correct, then HS 2220+2146 would be the first binary double white dwarf known to have formed through this channel. ESAs Gaia mission, currently underway, is expected to discover up to a million new white dwarfs, many of which will likely be in wide binary systems. Among these, we may well find many other systems like HS 2220+2146 that formed in the same way.CitationJeff J. Andrews et al 2016 ApJ 828 38. doi:10.3847/0004-637X/828/1/38

Stability of binaries. Part 1: Rigid binaries

NASA Astrophysics Data System (ADS)

Sharma, Ishan

2015-09-01

We consider the stability of binary asteroids whose members are possibly granular aggregates held together by self-gravity alone. A binary is said to be stable whenever each member is orbitally and structurally stable to both orbital and structural perturbations. To this end, we extend the stability test for rotating granular aggregates introduced by Sharma (Sharma, I. [2012]. J. Fluid Mech., 708, 71-99; Sharma, I. [2013]. Icarus, 223, 367-382; Sharma, I. [2014]. Icarus, 229, 278-294) to the case of binary systems comprised of rubble members. In part I, we specialize to the case of a binary with rigid members subjected to full three-dimensional perturbations. Finally, we employ the stability test to critically appraise shape models of four suspected binary systems, viz., 216 Kleopatra, 25143 Itokawa, 624 Hektor and 90 Antiope.

White dwarf-main sequence binaries from LAMOST: the DR5 catalogue

NASA Astrophysics Data System (ADS)

Ren, J.-J.; Rebassa-Mansergas, A.; Parsons, S. G.; Liu, X.-W.; Luo, A.-L.; Kong, X.; Zhang, H.-T.

2018-07-01

We present the data release (DR) 5 catalogue of white dwarf-main sequence (WDMS) binaries from the Large sky Area Multi-Object fibre Spectroscopic Telescope (LAMOST). The catalogue contains 876 WDMS binaries, of which 757 are additions to our previous LAMOST DR1 sample and 357 are systems that have not been published before. We also describe a LAMOST-dedicated survey that aims at obtaining spectra of photometrically selected WDMS binaries from the Sloan Digital Sky Survey (SDSS) that are expected to contain cool white dwarfs and/or early-type M dwarf companions. This is a population under-represented in previous SDSS WDMS binary catalogues. We determine the stellar parameters (white dwarf effective temperatures, surface gravities and masses, and M dwarf spectral types) of the LAMOST DR5 WDMS binaries and make use of the parameter distributions to analyse the properties of the sample. We find that, despite our efforts, systems containing cool white dwarfs remain under-represented. Moreover, we make use of LAMOST DR5 and SDSS DR14 (when available) spectra to measure the Na I λλ 8183.27, 8194.81 absorption doublet and/or Hα emission radial velocities of our systems. This allows identifying 128 binaries displaying significant radial velocity variations, 76 of which are new. Finally, we cross-match our catalogue with the Catalina Surveys and identify 57 systems displaying light-curve variations. These include 16 eclipsing systems, two of which are new, and nine binaries that are new eclipsing candidates. We calculate periodograms from the photometric data and measure (estimate) the orbital periods of 30 (15) WDMS binaries.

Flare Activity of Wide Binary Stars with Kepler

NASA Astrophysics Data System (ADS)

Clarke, Riley W.; Davenport, James R. A.; Covey, Kevin R.; Baranec, Christoph

2018-01-01

We present an analysis of flare activity in wide binary stars using a combination of value-added data sets from the NASA Kepler mission. The target list contains a set of previously discovered wide binary star systems identified by proper motions in the Kepler field. We cross-matched these systems with estimates of flare activity for ∼200,000 stars in the Kepler field, allowing us to compare relative flare luminosity between stars in coeval binaries. From a sample of 184 previously known wide binaries in the Kepler field, we find 58 with detectable flare activity in at least 1 component, 33 of which are similar in mass (q > 0.8). Of these 33 equal-mass binaries, the majority display similar (±1 dex) flare luminosity between both stars, as expected for stars of equal mass and age. However, we find two equal-mass pairs where the secondary (lower mass) star is more active than its counterpart, and two equal-mass pairs where the primary star is more active. The stellar rotation periods are also anomalously fast for stars with elevated flare activity. Pairs with discrepant rotation and activity qualitatively seem to have lower mass ratios. These outliers may be due to tidal spin-up, indicating these wide binaries could be hierarchical triple systems. We additionally present high-resolution adaptive optics images for two wide binary systems to test this hypothesis. The demographics of stellar rotation and magnetic activity between stars in wide binaries may be useful indicators for discerning the formation scenarios of these systems.

White dwarf-main sequence binaries from LAMOST: the DR5 catalogue

NASA Astrophysics Data System (ADS)

Ren, J.-J.; Rebassa-Mansergas, A.; Parsons, S. G.; Liu, X.-W.; Luo, A.-L.; Kong, X.; Zhang, H.-T.

2018-03-01

We present the data release (DR) 5 catalogue of white dwarf-main sequence (WDMS) binaries from the Large Area Multi-Object fiber Spectroscopic Telescope (LAMOST). The catalogue contains 876 WDMS binaries, of which 757 are additions to our previous LAMOST DR1 sample and 357 are systems that have not been published before. We also describe a LAMOST-dedicated survey that aims at obtaining spectra of photometrically-selected WDMS binaries from the Sloan Digital Sky Survey (SDSS) that are expected to contain cool white dwarfs and/or early type M dwarf companions. This is a population under-represented in previous SDSS WDMS binary catalogues. We determine the stellar parameters (white dwarf effective temperatures, surface gravities and masses, and M dwarf spectral types) of the LAMOST DR5 WDMS binaries and make use of the parameter distributions to analyse the properties of the sample. We find that, despite our efforts, systems containing cool white dwarfs remain under-represented. Moreover, we make use of LAMOST DR5 and SDSS DR14 (when available) spectra to measure the Na I λλ 8183.27, 8194.81 absorption doublet and/or Hα emission radial velocities of our systems. This allows identifying 128 binaries displaying significant radial velocity variations, 76 of which are new. Finally, we cross-match our catalogue with the Catalina Surveys and identify 57 systems displaying light curve variations. These include 16 eclipsing systems, two of which are new, and nine binaries that are new eclipsing candidates. We calculate periodograms from the photometric data and measure (estimate) the orbital periods of 30 (15) WDMS binaries.

Neurotransmitter systems and neurotrophic factors in autism: association study of 37 genes suggests involvement of DDC.

PubMed

Toma, Claudio; Hervás, Amaia; Balmaña, Noemí; Salgado, Marta; Maristany, Marta; Vilella, Elisabet; Aguilera, Francisco; Orejuela, Carmen; Cuscó, Ivon; Gallastegui, Fátima; Pérez-Jurado, Luis Alberto; Caballero-Andaluz, Rafaela; Diego-Otero, Yolanda de; Guzmán-Alvarez, Guadalupe; Ramos-Quiroga, Josep Antoni; Ribasés, Marta; Bayés, Mònica; Cormand, Bru

2013-09-01

Neurotransmitter systems and neurotrophic factors can be considered strong candidates for autism spectrum disorder (ASD). The serotoninergic and dopaminergic systems are involved in neurotransmission, brain maturation and cortical organization, while neurotrophic factors (NTFs) participate in neurodevelopment, neuronal survival and synapses formation. We aimed to test the contribution of these candidate pathways to autism through a case-control association study of genes selected both for their role in central nervous system functions and for pathophysiological evidences. The study sample consisted of 326 unrelated autistic patients and 350 gender-matched controls from Spain. We genotyped 369 tagSNPs to perform a case-control association study of 37 candidate genes. A significant association was obtained between the DDC gene and autism in the single-marker analysis (rs6592961, P = 0.00047). Haplotype-based analysis pinpointed a four-marker combination in this gene associated with the disorder (rs2329340C-rs2044859T-rs6592961A-rs11761683T, P = 4.988e-05). No significant results were obtained for the remaining genes after applying multiple testing corrections. However, the rs167771 marker in DRD3, associated with ASD in a previous study, displayed a nominal association in our analysis (P = 0.023). Our data suggest that common allelic variants in the DDC gene may be involved in autism susceptibility.

Contrasting genetic association of IL2RA with SLE and ANCA-associated vasculitis.

PubMed

Carr, Edward J; Clatworthy, Menna R; Lowe, Christopher E; Todd, John A; Wong, Andrew; Vyse, Timothy J; Kamesh, Lavanya; Watts, Richard A; Lyons, Paul A; Smith, Kenneth G C

2009-03-05

Autoimmune diseases are complex and have genetic and environmental susceptibility factors. The objective was to test the genetic association of systemic lupus erythematosus (SLE) and anti-neutrophil cytoplasmic antibody (ANCA) - associated systemic vasculitis (AAV) with SNPs in the IL2RA region and to correlate genotype with serum levels of IL-2RA. Using a cohort of over 700 AAV patients, two SLE case-control studies and an SLE trio collection (totalling over 1000 SLE patients), and a TaqMan genotyping approach, we tested 3 SNPs in the IL2RA locus, rs11594656, rs2104286 & rs41295061, each with a prior association with autoimmune disease; rs11594656 and rs41295061 with type 1 diabetes (T1D) and rs2104286 with multiple sclerosis (MS) and T1D. We show that SLE is associated with rs11594656 (P = 3.87 x 10-7) and there is some evidence of association of rs41295061 with AAV (P = 0.0122), which both have prior association with T1D. rs2104286, an MS and T1D - associated SNP in the IL2RA locus, is not associated with either SLE or AAV. We have confirmed a previous suggestion that the IL2RA locus is associated with SLE and showed some evidence of association with AAV. Soluble IL-2RA concentrations correlate with rs11594656 genotype in quiescent disease in both AAV and SLE. Differential association of autoimmune diseases and SNPs within the IL2RA locus suggests that the IL2RA pathway may prove to play differing, as yet undefined, roles in each disease.

Formation of close binary black holes merging due to gravitational-wave radiation

NASA Astrophysics Data System (ADS)

Tutukov, A. V.; Cherepashchuk, A. M.

2017-10-01

The conditions for the formation of close-binary black-hole systems merging over the Hubble time due to gravitational-wave radiation are considered in the framework of current ideas about the evolution of massive close-binary systems. The original systems whose mergers were detected by LIGO consisted of main-sequence stars with masses of 30-100 M ⊙. The preservation of the compactness of a binary black hole during the evolution of its components requires either the formation of a common envelope, probably also with a low initial abundance of metals, or the presence of a "kick"—a velocity obtained during a supernova explosion accompanied by the formation of a black hole. In principle, such a kick can explain the relatively low frequency of mergers of the components of close-binary stellar black holes, if the characteristic speed of the kick exceeds the orbital velocities of the system components during the supernova explosion. Another opportunity for the components of close-binary systems to approach each other is related to their possible motion in a dense molecular cloud.

Formation of S-type planets in close binaries: scattering induced tidal capture of circumbinary planets

NASA Astrophysics Data System (ADS)

Gong, Yan-Xiang; Ji, Jianghui

2018-05-01

Although several S-type and P-type planets in binary systems were discovered in past years, S-type planets have not yet been found in close binaries with an orbital separation not more than 5 au. Recent studies suggest that S-type planets in close binaries may be detected through high-accuracy observations. However, nowadays planet formation theories imply that it is difficult for S-type planets in close binaries systems to form in situ. In this work, we extensively perform numerical simulations to explore scenarios of planet-planet scattering among circumbinary planets and subsequent tidal capture in various binary configurations, to examine whether the mechanism can play a part in producing such kind of planets. Our results show that this mechanism is robust. The maximum capture probability is ˜10%, which can be comparable to the tidal capture probability of hot Jupiters in single star systems. The capture probability is related to binary configurations, where a smaller eccentricity or a low mass ratio of the binary will lead to a larger probability of capture, and vice versa. Furthermore, we find that S-type planets with retrograde orbits can be naturally produced via capture process. These planets on retrograde orbits can help us distinguish in situ formation and post-capture origin for S-type planet in close binaries systems. The forthcoming missions (PLATO) will provide the opportunity and feasibility to detect such planets. Our work provides several suggestions for selecting target binaries in search for S-type planets in the near future.

Efficient Retrieval of Massive Ocean Remote Sensing Images via a Cloud-Based Mean-Shift Algorithm.

PubMed

Yang, Mengzhao; Song, Wei; Mei, Haibin

2017-07-23

The rapid development of remote sensing (RS) technology has resulted in the proliferation of high-resolution images. There are challenges involved in not only storing large volumes of RS images but also in rapidly retrieving the images for ocean disaster analysis such as for storm surges and typhoon warnings. In this paper, we present an efficient retrieval of massive ocean RS images via a Cloud-based mean-shift algorithm. Distributed construction method via the pyramid model is proposed based on the maximum hierarchical layer algorithm and used to realize efficient storage structure of RS images on the Cloud platform. We achieve high-performance processing of massive RS images in the Hadoop system. Based on the pyramid Hadoop distributed file system (HDFS) storage method, an improved mean-shift algorithm for RS image retrieval is presented by fusion with the canopy algorithm via Hadoop MapReduce programming. The results show that the new method can achieve better performance for data storage than HDFS alone and WebGIS-based HDFS. Speedup and scaleup are very close to linear changes with an increase of RS images, which proves that image retrieval using our method is efficient.

Role of Fatty Acid Kinase in Cellular Lipid Homeostasis and SaeRS-Dependent Virulence Factor Expression in Staphylococcus aureus

PubMed Central

Ericson, Megan E.; Subramanian, Chitra; Frank, Matthew W.

2017-01-01

ABSTRACT The SaeRS two-component system is a master activator of virulence factor transcription in Staphylococcus aureus, but the cellular factors that control its activity are unknown. Fatty acid (FA) kinase is a two-component enzyme system required for extracellular FA uptake and SaeRS activity. Here, we demonstrate the existence of an intracellular nonesterified FA pool in S. aureus that is elevated in strains lacking FA kinase activity. SaeRS-mediated transcription is restored in FA kinase-negative strains when the intracellular FA pool is reduced either by growth with FA-depleted bovine serum albumin to extract the FA into the medium or by the heterologous expression of Neisseria gonorrhoeae acyl-acyl carrier protein synthetase to activate FA for phospholipid synthesis. These data show that FAs act as negative regulators of SaeRS signaling, and FA kinase activates SaeRS-dependent virulence factor production by lowering inhibitory FA levels. Thus, FA kinase plays a role in cellular lipid homeostasis by activating FA for incorporation into phospholipid, and it indirectly regulates SaeRS signaling by maintaining a low intracellular FA pool. PMID:28765222

Efficient Retrieval of Massive Ocean Remote Sensing Images via a Cloud-Based Mean-Shift Algorithm

PubMed Central

Song, Wei; Mei, Haibin

2017-01-01

The rapid development of remote sensing (RS) technology has resulted in the proliferation of high-resolution images. There are challenges involved in not only storing large volumes of RS images but also in rapidly retrieving the images for ocean disaster analysis such as for storm surges and typhoon warnings. In this paper, we present an efficient retrieval of massive ocean RS images via a Cloud-based mean-shift algorithm. Distributed construction method via the pyramid model is proposed based on the maximum hierarchical layer algorithm and used to realize efficient storage structure of RS images on the Cloud platform. We achieve high-performance processing of massive RS images in the Hadoop system. Based on the pyramid Hadoop distributed file system (HDFS) storage method, an improved mean-shift algorithm for RS image retrieval is presented by fusion with the canopy algorithm via Hadoop MapReduce programming. The results show that the new method can achieve better performance for data storage than HDFS alone and WebGIS-based HDFS. Speedup and scaleup are very close to linear changes with an increase of RS images, which proves that image retrieval using our method is efficient. PMID:28737699

Binary Lenses in OGLE-III EWS Database. Seasons 2002-2003

NASA Astrophysics Data System (ADS)

Jaroszynski, M.; Udalski, A.; Kubiak, M.; Szymanski, M.; Pietrzynski, G.; Soszynski, I.; Zebrun, K.; Szewczyk, O.; Wyrzykowski, L.

2004-06-01

We present 15 binary lens candidates from OGLE-III Early Warning System database for seasons 2002-2003. We also found 15 events interpreted as single mass lensing of double sources. The candidates were selected by visual light curves inspection. Examining the models of binary lenses of this and our previous study (10 caustic crossing events of OGLE-II seasons 1997--1999) we find one case of extreme mass ratio binary (q approx 0.005) and the rest in the range 0.1

Waveform model for an eccentric binary black hole based on the effective-one-body-numerical-relativity formalism

NASA Astrophysics Data System (ADS)

Cao, Zhoujian; Han, Wen-Biao

2017-08-01

Binary black hole systems are among the most important sources for gravitational wave detection. They are also good objects for theoretical research for general relativity. A gravitational waveform template is important to data analysis. An effective-one-body-numerical-relativity (EOBNR) model has played an essential role in the LIGO data analysis. For future space-based gravitational wave detection, many binary systems will admit a somewhat orbit eccentricity. At the same time, the eccentric binary is also an interesting topic for theoretical study in general relativity. In this paper, we construct the first eccentric binary waveform model based on an effective-one-body-numerical-relativity framework. Our basic assumption in the model construction is that the involved eccentricity is small. We have compared our eccentric EOBNR model to the circular one used in the LIGO data analysis. We have also tested our eccentric EOBNR model against another recently proposed eccentric binary waveform model; against numerical relativity simulation results; and against perturbation approximation results for extreme mass ratio binary systems. Compared to numerical relativity simulations with an eccentricity as large as about 0.2, the overlap factor for our eccentric EOBNR model is better than 0.98 for all tested cases, including spinless binary and spinning binary, equal mass binary, and unequal mass binary. Hopefully, our eccentric model can be the starting point to develop a faithful template for future space-based gravitational wave detectors.

NASA Conducts Final RS-25 Rocket Engine Test of 2017

NASA Image and Video Library

2017-12-13

NASA engineers at Stennis Space Center capped a year of Space Launch System testing with a final RS-25 rocket engine hot fire on Dec. 13. The 470-second test on the A-1 Test Stand was a “green run” test of an RS-25 flight controller. The engine tested also included a large 3-D-printed part, a pogo accumulator assembly, scheduled for use on future RS-25 flight engines.

How do accretion discs break?

NASA Astrophysics Data System (ADS)

Dogan, Suzan

2016-07-01

Accretion discs are common in binary systems, and they are often found to be misaligned with respect to the binary orbit. The gravitational torque from a companion induces nodal precession in misaligned disc orbits. In this study, we first calculate whether this precession is strong enough to overcome the internal disc torques communicating angular momentum. We compare the disc precession torque with the disc viscous torque to determine whether the disc should warp or break. For typical parameters precession wins: the disc breaks into distinct planes that precess effectively independently. To check our analytical findings, we perform 3D hydrodynamical numerical simulations using the PHANTOM smoothed particle hydrodynamics code, and confirm that disc breaking is widespread and enhances accretion on to the central object. For some inclinations, the disc goes through strong Kozai cycles. Disc breaking promotes markedly enhanced and variable accretion and potentially produces high-energy particles or radiation through shocks. This would have significant implications for all binary systems: e.g. accretion outbursts in X-ray binaries and fuelling supermassive black hole (SMBH) binaries. The behaviour we have discussed in this work is relevant to a variety of astrophysical systems, for example X-ray binaries, where the disc plane may be tilted by radiation warping, SMBH binaries, where accretion of misaligned gas can create effectively random inclinations and protostellar binaries, where a disc may be misaligned by a variety of effects such as binary capture/exchange, accretion after binary formation.

The comprehensive immunomodulation of NeurimmiRs in haemocytes of oyster Crassostrea gigas after acetylcholine and norepinephrine stimulation.

PubMed

Chen, Hao; Wang, Lingling; Zhou, Zhi; Hou, Zhanhui; Liu, Zhaoqun; Wang, Weilin; Gao, Dahai; Gao, Qiang; Wang, Mengqiang; Song, Linsheng

2015-11-14

Neural-endocrine-immune (NEI) system is a major modulation network among the nervous, endocrine and immune system and weights greatly in maintaining homeostasis of organisms during stress and infection. Some microRNAs are found interacting with NEI system (designated NeurimmiRs), addressing swift modulations on immune system. The oyster Crassostrea gigas, as an intertidal bivalve, has evolved a primary NEI system. However, the knowledge about NeurimmiRs in oysters remains largely unknown. Six small RNA libraries from haemocytes of oysters stimulated with acetylcholine (ACh) and norepinephrine (NE) were sequenced to identify neurotransmitter-responsive miRNAs and survey their immunomodulation roles. A total of 331 miRNAs (132 identified in the present study plus 199 identified previously) were subjected to expression analysis, and twenty-one and sixteen of them were found ACh- or NE-responsive, respectively (FDR < 0.05). Meanwhile, 21 miRNAs exhibited different expression pattern after ACh or NE stimulation. Consequently, 355 genes were predicted as putative targets of these neurotransmitter-responsive miRNAs in oyster. Through gene onthology analysis, multiple genes involved in death, immune system process and response to stimulus were annotated to be modulated by NeurimmiRs. Besides, a significant decrease in haemocyte phagocytosis and late-apoptosis or necrosis rate was observed after ACh and NE stimulation (p < 0.05) while early-apoptosis rate remained unchanged. A comprehensive immune-related network involving PRRs, intracellular receptors, signaling transducers and immune effectors was proposed to be modulated by ACh- and NE-responsive NeurimmiRs, which would be indispensable for oyster haemocytes to respond against stress and infection. Characterization of the NeurimmiRs would be an essential step to understand the NEI system of invertebrate and the adaptation mechanism of oyster.

Effects of Disk Warping on the Inclination Evolution of Star-Disk-Binary Systems

NASA Astrophysics Data System (ADS)

Zanazzi, J. J.; Lai, Dong

2018-04-01

Several recent studies have suggested that circumstellar disks in young stellar binaries may be driven into misalignement with their host stars due to secular gravitational interactions between the star, disk and the binary companion. The disk in such systems is twisted/warped due to the gravitational torques from the oblate central star and the external companion. We calculate the disk warp profile, taking into account of bending wave propagation and viscosity in the disk. We show that for typical protostellar disk parameters, the disk warp is small, thereby justifying the "flat-disk" approximation adopted in previous theoretical studies. However, the viscous dissipation associated with the small disk warp/twist tends to drive the disk toward alignment with the binary or the central star. We calculate the relevant timescales for the alignment. We find the alignment is effective for sufficiently cold disks with strong external torques, especially for systems with rapidly rotating stars, but is ineffective for the majority of star-disk-binary systems. Viscous warp driven alignment may be necessary to account for the observed spin-orbit alignment in multi-planet systems if these systems are accompanied by an inclined binary companion.

Effects of disc warping on the inclination evolution of star-disc-binary systems

NASA Astrophysics Data System (ADS)

Zanazzi, J. J.; Lai, Dong

2018-07-01

Several recent studies have suggested that circumstellar discs in young stellar binaries may be driven into misalignement with their host stars due to the secular gravitational interactions between the star, disc, and the binary companion. The disc in such systems is twisted/warped due to the gravitational torques from the oblate central star and the external companion. We calculate the disc warp profile, taking into account the bending wave propagation and viscosity in the disc. We show that for typical protostellar disc parameters, the disc warp is small, thereby justifying the `flat-disc' approximation adopted in previous theoretical studies. However, the viscous dissipation associated with the small disc warp/twist tends to drive the disc towards alignment with the binary or the central star. We calculate the relevant time-scales for the alignment. We find that the alignment is effective for sufficiently cold discs with strong external torques, especially for systems with rapidly rotating stars, but is ineffective for the majority of the star-disc-binary systems. Viscous warp-driven alignment may be necessary to account for the observed spin-orbit alignment in multiplanet systems if these systems are accompanied by an inclined binary companion.

Bondi-Hoyle-Lyttleton Accretion onto Binaries

NASA Astrophysics Data System (ADS)

Antoni, Andrea; MacLeod, Morgan; Ramírez-Ruiz, Enrico

2018-01-01

Binary stars are not rare. While only close binary stars will eventually interact with one another, even the widest binary systems interact with their gaseous surroundings. The rates of accretion and the gaseous drag forces arising in these interactions are the key to understanding how these systems evolve. This poster examines accretion flows around a binary system moving supersonically through a background gas. We perform three-dimensional hydrodynamic simulations of Bondi-Hoyle-Lyttleton accretion using the adaptive mesh refinement code FLASH. We simulate a range of values of semi-major axis of the orbit relative to the gravitational focusing impact parameter of the pair. On large scales, gas is gravitationally focused by the center-of-mass of the binary, leading to dynamical friction drag and to the accretion of mass and momentum. On smaller scales, the orbital motion imprints itself on the gas. Notably, the magnitude and direction of the forces acting on the binary inherit this orbital dependence. The long-term evolution of the binary is determined by the timescales for accretion, slow down of the center-of-mass, and decay of the orbit. We use our simulations to measure these timescales and to establish a hierarchy between them. In general, our simulations indicate that binaries moving through gaseous media will slow down before the orbit decays.

The Eclipsing Central Stars of the Planetary Nebulae Lo 16 and PHR J1040-5417

NASA Astrophysics Data System (ADS)

Hillwig, Todd C.; Frew, David; Jones, David; Crispo, Danielle

2017-01-01

Binary central stars of planetary nebula are a valuable tool in understanding common envelope evolution. In these cases both the resulting close binary system and the expanding envelope (the planetary nebula) can be studied directly. In order to compare observed systems with common envelope evolution models we need to determine precise physical parameters of the binaries and the nebulae. Eclipsing central stars provide us with the best opportunity to determine high precision values for mass, radius, and temperature of the component stars in these close binaries. We present photometry and spectroscopy for two of these eclipsing systems; the central stars of Lo 16 and PHR 1040-5417. Using light curves and radial velocity curves along with binary modeling we provide physical parameters for the stars in both of these systems.

Dynamical effects of stellar companions

NASA Astrophysics Data System (ADS)

Naoz, Smadar

2015-08-01

The fraction of stellar binaries in the field is extremely high (about 40% - 70% for > 1 Msun stars), and thus, given this frequency, a large fraction of all exoplanetary systems may reside in binaries. While close-in giant planets tend to be found preferentially in binary stellar systems it seems that the frequency of giant planets in close binaries (<100 AU) is significantly lower than in the overall population. Stellar companions’ gravitational perturbations may significantly alter the planetary orbits around their partner on secular timescales. They can drive planets to large eccentric orbits which can either result in plunging these planets into the star or shrinking their orbits and forming short period planets. I will review the dynamical effects stellar binaries have on a planetary systems. I will also present new results on the influence that stellar evolution has on the dynamical processes in these systems.

Assessing the performance of formulations for nonlinear feedback of surface gravity waves on ocean currents over coastal waters

NASA Astrophysics Data System (ADS)

Wang, Pengcheng; Sheng, Jinyu; Hannah, Charles

2017-08-01

This study presents applications of a two-way coupled wave-circulation modelling system over coastal waters, with a special emphasis of performance assessments of two different methods for nonlinear feedback of ocean surface gravity waves on three-dimensional (3D) ocean currents. These two methods are the vortex force (VF) formulation suggested by Bennis et al. (2011) and the latest version of radiation stress (RS) formulation suggested by Mellor (2015). The coupled modelling system is first applied to two idealized test cases of surf-zone scales to validate implementations of these two methods in the coupled wave-circulation system. Model results show that the latest version of RS has difficulties in producing the undertow over the surf zone. The coupled system is then applied to Lunenburg Bay (LB) of Nova Scotia during Hurricane Juan in 2003. The coupled system using both the VF and RS formulations generates much stronger and more realistic 3D circulation in the Bay during Hurricane Juan than the circulation-only model, demonstrating the importance of surface wave forces to the 3D ocean circulation over coastal waters. However, the RS formulation generates some weak unphysical currents outside the wave breaking zone due to a less reasonable representation for the vertical distribution of the RS gradients over a slopping bottom. These weak unphysical currents are significantly magnified in a two-way coupled system when interacting with large surface waves, degrading the model performance in simulating currents at one observation site. Our results demonstrate that the VF formulation with an appropriate parameterization of wave breaking effects is able to produce reasonable results for applications over coastal waters during extreme weather events. The RS formulation requires a complex wave theory rather than the linear wave theory for the approximation of a vertical RS term to improve its performance under both breaking and non-breaking wave conditions.

Next-Generation RS-25 Engines for the NASA Space Launch System

NASA Technical Reports Server (NTRS)

Ballard, Richard O.

2017-01-01

The utilization of heritage RS-25 engine, also known as the Space Shuttle Main Engine (SSME), has enabled rapid progress in the development and certification of the NASA Space Launch System (SLS) toward operational flight status. The RS-25 brings design maturity and extensive experience gained through 135 missions, 3000+ ground tests, and over a million seconds total accumulated hot-fire time. In addition, there were also over a dozen functional flight assets remaining from the Space Shuttle program that could be leveraged to support the first four flights. Beyond these initial SLS flights, NASA must have a renewed supply of RS-25 engines that must reflect program affordability imperatives as well as technical requirements imposed by the SLS Block-1B vehicle (i.e., 111% RPL power level, reduced service life). Recognizing the long lead times needed for the fabrication, assembly and acceptance testing of flight engines, design activities are underway at NASA and the RS-25 engine provider, Aerojet Rocketdyne, to improve system affordability and eliminate obsolescence concerns. This paper describes how the achievement of these key objectives are enabled largely by utilizing modern materials and fabrication technologies, but also by innovations in systems engineering and integration (SE&I) practices.

In vitro evaluation of resistance to sliding in self-ligating and conventional bracket systems during dental alignment.

PubMed

Cordasco, Giancarlo; Lo Giudice, Antonino; Militi, Angela; Nucera, Riccardo; Triolo, Giuseppe; Matarese, Giovanni

2012-08-01

To investigate the resistance to sliding (RS) in self-ligating and conventional ligation bracket systems at 5 different second-order bracket angulations by using low-stiffness alignment wires in a 3-bracket experimental model and to verify the performance of the main RS components in both systems when these wires are used. Interactive self-ligating brackets with closed and open slides were used for the self-ligating (SL) and conventional ligation (CL) groups, respectively; elastomeric ligatures (1 mm inner diameter) were used in the latter system. The alignment wire used was 0.014 inch heat-activated NiTi (austenitic finish temperature set at 36℃ by the manufacturer). A custom-made testing machine was used to measure frictional resistance. Tests were repeated 5 times at every angulation simulated. All data were analyzed statistically. The RS increased significantly with increasing angulation in both SL and CL groups (p < 0.0001). However, the RS values were significantly higher at every angulation (p < 0.0001) in the CL group. Despite the relevance of the binding phenomenon, ligation forces predominantly affect the RS when low-stiffness alignment wires are used.

In vitro evaluation of resistance to sliding in self-ligating and conventional bracket systems during dental alignment

PubMed Central

Cordasco, Giancarlo; Lo Giudice, Antonino; Militi, Angela; Nucera, Riccardo; Triolo, Giuseppe

2012-01-01

Objective To investigate the resistance to sliding (RS) in self-ligating and conventional ligation bracket systems at 5 different second-order bracket angulations by using low-stiffness alignment wires in a 3-bracket experimental model and to verify the performance of the main RS components in both systems when these wires are used. Methods Interactive self-ligating brackets with closed and open slides were used for the self-ligating (SL) and conventional ligation (CL) groups, respectively; elastomeric ligatures (1 mm inner diameter) were used in the latter system. The alignment wire used was 0.014 inch heat-activated NiTi (austenitic finish temperature set at 36℃ by the manufacturer). A custom-made testing machine was used to measure frictional resistance. Tests were repeated 5 times at every angulation simulated. All data were analyzed statistically. Results The RS increased significantly with increasing angulation in both SL and CL groups (p < 0.0001). However, the RS values were significantly higher at every angulation (p < 0.0001) in the CL group. Conclusions Despite the relevance of the binding phenomenon, ligation forces predominantly affect the RS when low-stiffness alignment wires are used. PMID:23112953

Identification of Quorum Sensing Signal Molecule of Lactobacillus delbrueckii subsp. bulgaricus.

PubMed

Pang, Xiaoyang; Liu, Cuiping; Lyu, Pengcheng; Zhang, Shuwen; Liu, Lu; Lu, Jing; Ma, Changlu; Lv, Jiaping

2016-12-14

Many bacteria in nature use quorum sensing (QS) to regulate gene expression. The quorum sensing system plays critical roles in the adaptation of bacteria to the surrounding environment. Previous studies have shown that during high-density fermentation, the autolysis of lactic acid bacteria was regulated by the QS system, and the two-component system (TCS, LBUL_RS00115/LBUL_RS00110) is involved in the autolysis of Lactobacillus delbrueckii subsp. bulgaricus. However, the QS signal molecule, which regulates this pathway, has not been identified. In this study, we compared the genome of Lactobacillus bulgaricus ATCC BAA-365 with the locus of seven lactobacillus QS systems; the position of the QS signal molecule of Lactobacillus bulgaricus ATCC BAA-365 was predicted by bioinformatics tool. Its function was identified by in vitro experiments. Construction of TCS mutant by gene knockout of LBUL_RS00115 confirmed that the signal molecule regulates the density of the flora by the TCS (LBUL_RS00115/LBUL_RS00110). This study indicated that quorum quenching and inhibition based on the signal molecule might serve as an approach to reduce the rate of autolysis of LAB and increase the number of live bacteria in fermentation.

EmbRS a new two-component system that inhibits biofilm formation and saves Rubrivivax gelatinosus from sinking.

PubMed

Steunou, Anne Soisig; Liotenberg, Sylviane; Soler, Marie-Noêlle; Briandet, Romain; Barbe, Valérie; Astier, Chantal; Ouchane, Soufian

2013-06-01

Photosynthetic bacteria can switch from planktonic lifestyle to phototrophic biofilm in mats in response to environmental changes. The mechanisms of phototrophic biofilm formation are, however, not characterized. Herein, we report a two-component system EmbRS that controls the biofilm formation in a photosynthetic member of the Burkholderiales order, the purple bacterium Rubrivivax gelatinosus. EmbRS inactivation results in cells that form conspicuous bacterial veils and fast-sinking aggregates in liquid. Biofilm analyses indicated that EmbRS represses the production of an extracellular matrix and biofilm formation. Mapping of transposon mutants that partially or completely restore the wild-type (WT) phenotype allowed the identification of two gene clusters involved in polysaccharide synthesis, one fully conserved only in Thauera sp., a floc-forming wastewater bacterium. A second two-component system BmfRS and a putative diguanylate cyclase BdcA were also identified in this screen suggesting their involvement in biofilm formation in this bacterium. The role of polysaccharides in sinking of microorganisms and organic matter, as well as the importance and the evolution of such regulatory system in phototrophic microorganisms are discussed. © 2013 The Authors. Microbiology Open published by John Wiley & Sons Ltd.

Hierarchically self-assembled hexagonal honeycomb and kagome superlattices of binary 1D colloids.

PubMed

Lim, Sung-Hwan; Lee, Taehoon; Oh, Younghoon; Narayanan, Theyencheri; Sung, Bong June; Choi, Sung-Min

2017-08-25

Synthesis of binary nanoparticle superlattices has attracted attention for a broad spectrum of potential applications. However, this has remained challenging for one-dimensional nanoparticle systems. In this study, we investigate the packing behavior of one-dimensional nanoparticles of different diameters into a hexagonally packed cylindrical micellar system and demonstrate that binary one-dimensional nanoparticle superlattices of two different symmetries can be obtained by tuning particle diameter and mixing ratios. The hexagonal arrays of one-dimensional nanoparticles are embedded in the honeycomb lattices (for AB 2 type) or kagome lattices (for AB 3 type) of micellar cylinders. The maximization of free volume entropy is considered as the main driving force for the formation of superlattices, which is well supported by our theoretical free energy calculations. Our approach provides a route for fabricating binary one-dimensional nanoparticle superlattices and may be applicable for inorganic one-dimensional nanoparticle systems.Binary mixtures of 1D particles are rarely observed to cooperatively self-assemble into binary superlattices, as the particle types separate into phases. Here, the authors design a system that avoids phase separation, obtaining binary superlattices with different symmetries by simply tuning the particle diameter and mixture composition.

Individual Component Map of Rotatory Strength (ICM-RS) and Rotatory Strength Density (RSD) plots as analysis tools of circular dicroism spectra of complex systems.

PubMed

Chang, Le; Baseggio, Oscar; Sementa, Luca; Cheng, Daojian; Fronzoni, Giovanna; Toffoli, Daniele; Aprà, Edoardo; Stener, Mauro; Fortunelli, Alessandro

2018-06-13

We introduce Individual Component Maps of Rotatory Strength (ICM-RS) and Rotatory Strength Density (RSD) plots as analysis tools of chiro-optical linear response spectra deriving from time-dependent density functional theory (TDDFT) simulations. ICM-RS and RSD allow one to visualize the origin of chiro-optical response in momentum or real space, including signed contributions and therefore highlighting cancellation terms that are ubiquitous in chirality phenomena, and should be especially useful in analyzing the spectra of complex systems. As test cases, we use ICM-RS and RSD to analyze circular dichroism spectra of selected (Ag-Au)30(SR)18 monolayer-protected metal nanoclusters, showing the potential of the proposed tools to derive insight and understanding, and eventually rational design, in chiro-optical studies of complex systems.

Physical Identification of Binary System of Gliclazide-Hydrophilic Polymers Using X-Ray Diffraction

NASA Astrophysics Data System (ADS)

Rachmawati, H.; Yatinasari, Faizatun, Syarie, S. A.

2008-03-01

The formation of binary system in pharmaceutical solid state is aimed to improve the physicochemical characteristics of active compound, such as its solubility. To identify the physical change of the binary system including crystallinity or particle morphology, there are many methods can be applied. In present report, we study the physical interaction of the binary system of gliclazide and hydrophilic polymers. In this binary system, gliclazide was either dispersed or mixed with polyvinyl pirrolidone (PVP K30) or polyethylene glycol (PEG 6000). The dispersion system of gliclazide in the polymeric carriers was prepared by solvation-evaporation method, using dichloromethane/methylene chloride as an organic solvent. The physical characterization of both dispersed and mixed of gliclazide was studied using X-ray diffraction at interval 6-50 °/2θ. As a comparison, the same procedure was performed for pure gliclazide. To confirm the diffractogram of this binary system, Fourier Transform Infrared (FT-IR) spectroscopy was carried out as well. Both diffarctogram and FT-IR spectra revealed that there was no new compound formed in the solid dispersion system of gliclazide:PEG 6000 and gliclazide:PVP K30. In contrast, the solubility as well as the dissolution rate of gliclazide in the presence of both hydrophilic polymers was increased as compared to pure gliclazide. We conclude therefore that solvatation followed by evaporation of gliclazide in the presence of either PEG 6000 or PVP K30 did not alter its crystalline characteristic. The improved of gliclazide solubility in the binary system might due to other mechanism such as increased in the wettability and the hydrophylicity effect of the polymers.

A Pulsar and White Dwarf in an Unexpected Orbit

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2016-11-01

Astronomers have discovered a binary system consisting of a low-mass white dwarf and a millisecond pulsar but its eccentric orbit defies all expectations of how such binaries form.Observed orbital periods and binary eccentricities for binary millisecond pulsars. PSR J2234+0511 is the furthest right of the green stars that mark the five known eccentric systems. [Antoniadis et al. 2016]Unusual EccentricityIt would take a low-mass (0.4 solar masses) white dwarf over 100 billion years to form from the evolution of a single star. Since this is longer than the age of the universe, we believe that these lightweights are instead products of binary-star evolution and indeed, we observe many of these stars to still be in binary systems.But the binary evolution that can create a low-mass white dwarf includes a period of mass transfer, in which efficient tidal dissipation damps the systems orbital eccentricity. Because of this, we would expect all systems containing low-mass white dwarfs to have circular orbits.In the past, our observations of low-mass white dwarfmillisecond pulsar binaries have all been consistent with this expectation. But a new detection has thrown a wrench in the works: the unambiguous identification of a low-mass white dwarf thats in an eccentric (e=0.13) orbit with the millisecond pulsar PSR J2234+0511. How could this system have formed?Eliminating Formation ModelsLed by John Antoniadis (Dunlap Institute at University of Toronto), a team of scientists has used newly obtained optical photometry (from the Sloan Digital Sky Survey) and spectroscopy (from the Very Large Telescope in Chile) of the white dwarf to confirm the identification of this system.Antoniadis and collaborators then use measurements of the bodies masses (0.28 and 1.4 solar masses for the white dwarf and pulsar, respectively) and velocities, and constraints on the white dwarfs temperature, radius and surface gravity, to address three proposed models for the formation of this system.The 3D motion of the pulsar (black solid lines; current position marked with diamond) in our galaxy over the past 1.5 Gyr. This motion is typical for low-mass X-ray binary descendants, favoring a binary-evolution model over a 3-body-interaction model. [Antoniadis et al. 2016]In the first model, the eccentric binary was created via adynamic three-body formation channel. This possibility is deemed unlikely, as the white-dwarf properties and all the kinematic properties of the system point to normal binary evolution.In the secondmodel, the binary system gains its high eccentricity after mass transfer ends, when the pulsar progenitor experiences a spontaneous phase transition. The authors explore two options for this: one in which the neutron star implodes into a strange-quark star, and the other in which an over-massive white dwarf suffers a delayed collapse into a neutron star. Both cases are deemed unlikely, because the mass inferred for the pulsar progenitor is not consistent with either model.In the third model, the system forms a circumbinary disk fueled by material escaping the proto-white dwarf. After mass transfer has ended, interactions between the binary and its disk gradually increase the eccentricity of the system, pumping it up to what we observe today. All of the properties of the system measured by Antoniadis and collaborators are thus far consistent with this model.Further observations of this system and systems like it (several others have been detected, though not yet confirmed) will help determine whether binary evolution combined with interactions with a disk can indeed explain the formation of this unexpectedly eccentricsystem.CitationJohn Antoniadis et al 2016 ApJ 830 36. doi:10.3847/0004-637X/830/1/36

Dinitrosyl iron complexes and S-nitrosothiols are two possible forms for stabilization and transport of nitric oxide in biological systems.

PubMed

Vanin, A F

1998-07-01

The physicochemical properties, mechanisms of synthesis and decomposition of dinitrosyl iron complexes (DNICs) with thiol-containing ligands and of S-nitrosothiols (RS-NO), and the potential role of these compounds in storage and transport of NO in biological systems are reviewed. Special attention is given to the phenomenon of mutual transformation of DNIC and RS-NO catalyzed by Fe2+. Each Fe2+ binds two neutral NO molecules in the DNICs, catalyzes their mutual oxidation--reduction with formation of nitrous oxide and nitrosonium ions appearing in the DNICs. These ions S-nitrosate thiol-compounds with RS-NO formation. Fe2+ binds two RS-NO molecules and catalyzes their mutual oxidation--reduction followed by decomposition of the resulting molecules. Mutual conversion of DNICs and RS-NO regulated by iron, thiol, and NO levels is suggested to provide NO transport in cells and tissues.

Inferences about binary stellar populations using gravitational wave observations

NASA Astrophysics Data System (ADS)

Wysocki, Daniel; Gerosa, Davide; O'Shaughnessy, Richard; Belczynski, Krzysztof; Gladysz, Wojciech; Berti, Emanuele; Kesden, Michael; Holz, Daniel

2018-01-01

With the dawn of gravitational wave astronomy, enabled by the LIGO and Virgo interferometers, we now have a new window into the Universe. In the short time these detectors have been in use, multiple confirmed detections of gravitational waves from compact binary coalescences have been made. Stellar binary systems are one of the likely progenitors of the observed compact binary sources. If this is indeed the case, then we can use measured properties of these binary systems to learn about their progenitors. We will discuss the Bayesian framework in which we make these inferences, and results which include mass and spin distributions.

Genetic dissection of host immune response in pneumonia development and progression

PubMed Central

Smelaya, Tamara V.; Belopolskaya, Olesya B.; Smirnova, Svetlana V.; Kuzovlev, Artem N.; Moroz, Viktor V.; Golubev, Arkadiy M.; Pabalan, Noel A.; Salnikova, Lyubov E.

2016-01-01

The role of host genetic variation in pneumonia development and outcome is poorly understood. We studied common polymorphisms in the genes of proinflammatory cytokines (IL6 rs1800795, IL8 rs4073, IL1B rs16944), anti-inflammatory cytokines (IL10 rs1800896, IL4 rs2243250, IL13 rs20541) and toll-like receptors (TLR2 rs5743708 and rs4696480, TLR4 rs4986791, TLR9 rs352139, rs5743836 and rs187084) in patients with community-acquired pneumonia (CAP) (390 cases, 203 controls) and nosocomial pneumonia (355 cases, 216 controls). Experimental data were included in a series of 11 meta-analyses and eight subset analyses related to pneumonia susceptibility and outcome. TLR2 rs5743708 minor genotype appeared to be associated with CAP/Legionnaires’ disease/pneumococcal disease. In CAP patients, the IL6 rs1800795-C allele was associated with severe sepsis/septic shock/severe systemic inflammatory response, while the IL10 rs1800896-A allele protected against the development of these critical conditions. To contribute to deciphering of the above results, we performed an in silico analysis and a qualitative synthesis of literature data addressing basal and stimulated genotype-specific expression level. This data together with database information on transcription factors’ affinity changes caused by SNPs in putative promoter regions, the results of linkage disequilibrium analysis along with SNPs functional annotations supported assumptions about the complexity underlying the revealed associations. PMID:27725770

Isobaric vapor-liquid equilibria for binary systems α-phenylethylamine + toluene and α-phenylethylamine + cyclohexane at 100 kPa

NASA Astrophysics Data System (ADS)

Wu, Xiaoru; Gao, Yingyu; Ban, Chunlan; Huang, Qiang

2016-09-01

In this paper the results of the vapor-liquid equilibria study at 100 kPa are presented for two binary systems: α-phenylethylamine(1) + toluene (2) and (α-phenylethylamine(1) + cyclohexane(2)). The binary VLE data of the two systems were correlated by the Wilson, NRTL, and UNIQUAC models. For each binary system the deviations between the results of the correlations and the experimental data have been calculated. For the both binary systems the average relative deviations in temperature for the three models were lower than 0.99%. The average absolute deviations in vapour phase composition (mole fractions) and in temperature T were lower than 0.0271 and 1.93 K, respectively. Thermodynamic consistency has been tested for all vapor-liquid equilibrium data by the Herrington method. The values calculated by Wilson and NRTL equations satisfied the thermodynamics consistency test for the both two systems, while the values calculated by UNIQUAC equation didn't.

KIC 7177553: A QUADRUPLE SYSTEM OF TWO CLOSE BINARIES

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

Lehmann, H.; Borkovits, T.; Rappaport, S. A.

2016-03-01

KIC 7177553 was observed by the Kepler satellite to be an eclipsing eccentric binary star system with an 18-day orbital period. Recently, an eclipse timing study of the Kepler binaries has revealed eclipse timing variations (ETVs) in this object with an amplitude of ∼100 s and an outer period of 529 days. The implied mass of the third body is that of a super-Jupiter, but below the mass of a brown dwarf. We therefore embarked on a radial velocity (RV) study of this binary to determine its system configuration and to check the hypothesis that it hosts a giant planet. Frommore » the RV measurements, it became immediately obvious that the same Kepler target contains another eccentric binary, this one with a 16.5-day orbital period. Direct imaging using adaptive optics reveals that the two binaries are separated by 0.″4 (∼167 AU) and have nearly the same magnitude (to within 2%). The close angular proximity of the two binaries and very similar γ velocities strongly suggest that KIC 7177553 is one of the rare SB4 systems consisting of two eccentric binaries where at least one system is eclipsing. Both systems consist of slowly rotating, nonevolved, solar-like stars of comparable masses. From the orbital separation and the small difference in γ velocity, we infer that the period of the outer orbit most likely lies in the range of 1000–3000 yr. New images taken over the next few years, as well as the high-precision astrometry of the Gaia satellite mission, will allow us to set much narrower constraints on the system geometry. Finally, we note that the observed ETVs in the Kepler data cannot be produced by the second binary. Further spectroscopic observations on a longer timescale will be required to prove the existence of the massive planet.« less

Wind-accelerated orbital evolution in binary systems with giant stars

NASA Astrophysics Data System (ADS)

Chen, Zhuo; Blackman, Eric G.; Nordhaus, Jason; Frank, Adam; Carroll-Nellenback, Jonathan

2018-01-01

Using 3D radiation-hydrodynamic simulations and analytic theory, we study the orbital evolution of asymptotic giant branch (AGB) binary systems for various initial orbital separations and mass ratios, and thus different initial accretion modes. The time evolution of binary separations and orbital periods are calculated directly from the averaged mass-loss rate, accretion rate and angular momentum loss rate. We separately consider spin-orbit synchronized and zero-spin AGB cases. We find that the angular momentum carried away by the mass loss together with the mass transfer can effectively shrink the orbit when accretion occurs via wind-Roche lobe overflow. In contrast, the larger fraction of mass lost in Bondi-Hoyle-Lyttleton accreting systems acts to enlarge the orbit. Synchronized binaries tend to experience stronger orbital period decay in close binaries. We also find that orbital period decay is faster when we account for the non-linear evolution of the accretion mode as the binary starts to tighten. This can increase the fraction of binaries that result in common envelope, luminous red novae, Type Ia supernovae and planetary nebulae with tight central binaries. The results also imply that planets in the habitable zone around white dwarfs are unlikely to be found.

Marginal and internal discrepancies of zirconia copings: effects of milling system and finish line design.

PubMed

Ribeiro, Isabella Lima Arrais; Campos, Fernanda; Sousa, Rafael Santiago; Alves, Maria Luiza Lima; Rodrigues, Dalton Matos; Souza, Rodrigo Othavio Assuncão; Bottino, Marco Antonio

2015-01-01

Discrepancies at the abutment/crown interface can affect the longevity of zirconia restorations. The aim was to evaluate the marginal and internal discrepancies (MD and ID) of zirconia copings manufactured by two milling systems with different finish lines. Three aluminum-master-dies (h = 5.5 mm; Ψ =7.5 mm; 6΀), with different finish lines (large chamfer [LC]; tilted chamfer [TC]; rounded shoulder [RS]) were fabricated. Twenty impressions were made from each master die and poured. Sixty zirconia copings were manufactured and divided according to the factors "finish line" and "milling system" (n = 10): CAD LC = Computer-aided design/computer-aided manufacturing (CAD/CAM) + LC; CAD TC = CAD/CAM + TC; CAD RS = CAD/CAM + RS; MAD LC = manually aided design/manually aided manufacturing (MAD/MAM) + LC; MAD TC = MAD/MAM + TC; and MAD RS = MAD/MAM + RS. For MD analysis, each coping was fixed, and the distance between the external edges of the coping and the edge of the cervical preparation was measured (50 points). Using the same copings, the ID of each coping was evaluated, by the replica technique, at 12 points equally distributed among the regions (n = 10): Ray (R), axial (A), and occlusal (Occl). The measurements were performed by optical microscopy (Χ250). The data (μm) were subjected to parametric and non-parametric statistical analyses. For the MAD/MAM system, the "finish line" (P = 0.0001) affected significantly the MD median values (μm): LC = 251.80 a , RS = 68.40 a and TC = 8.10 b (Dunn's test). For the CAD/CAM system, the median MD values (μm) were not affected by the factor "finish line" (P = 0.4037): LC = 0.82 a , RS = 0.52 a , and TC = 0.89 a . For the ID, it was observed interaction between the finish line types and the region (P = 0.0001) and between region and milling system (P = 0.0031) (RM-ANOVA). The CAD/CAM system presented lower MD values, regardless the finish line. However, the MAD/MAM system showed ID values smaller than those of CAD/CAM.

Video File - NASA Conducts Final RS-25 Rocket Engine Test of 2017

NASA Image and Video Library

2017-12-13

NASA engineers at Stennis Space Center capped a year of Space Launch System testing with a final RS-25 rocket engine hot fire on Dec. 13. The 470-second test on the A-1 Test Stand was a “green run” test of an RS-25 flight controller. The engine tested also included a large 3-D-printed part, a pogo accumulator assembly, scheduled for use on future RS-25 flight engines.

Constraining Binary Asteroid Mass Distributions Based On Mutual Motion

NASA Astrophysics Data System (ADS)

Davis, Alex B.; Scheeres, Daniel J.

2017-06-01

The mutual gravitational potential and torques of binary asteroid systems results in a complex coupling of attitude and orbital motion based on the mass distribution of each body. For a doubly-synchronous binary system observations of the mutual motion can be leveraged to identify and measure the unique mass distributions of each body. By implementing arbitrary shape and order computation of the full two-body problem (F2BP) equilibria we study the influence of asteroid asymmetries on separation and orientation of a doubly-synchronous system. Additionally, simulations of binary systems perturbed from doubly-synchronous behavior are studied to understand the effects of mass distribution perturbations on precession and nutation rates such that unique behaviors can be isolated and used to measure asteroid mass distributions. We apply our investigation to the Trojan binary asteroid system 617 Patroclus and Menoetius (1906 VY), which will be the final flyby target of the recently announced LUCY Discovery mission in March 2033. This binary asteroid system is of particular interest due to the results of a recent stellar occultation study (DPS 46, id.506.09) that suggests the system to be doubly-synchronous and consisting of two-similarly sized oblate ellipsoids, in addition to suggesting the presence mass asymmetries resulting from an impact crater on the southern limb of Menoetius.

Combined effects of age and polymorphisms in Notch3 in the pathogenesis of cerebral infarction disease.

PubMed

Zhu, Chun-Yu; Wang, Yue; Zeng, Qing-Xuan; Qian, Yu; Li, Huan; Yang, Zi-Xia; Yang, Ya-Mei; Zhang, Qiong; Li, Fei-Feng; Liu, Shu-Lin

2016-10-01

Cerebral infarction disease is a severe hypoxic ischemic tissue necrosis in the brain, often leading to long-term functional disability and residual impairments. The Notch signaling pathway plays key roles in proliferation and survival of the stem/progenitor cells of the central and peripheral nervous systems. Notch3 is an important member of the pathway, but the relationships between the genetic abnormalities and cerebral infarction disease still remain unclear. The aim of this work was to evaluate variations in Notch3 gene for their possible associations with the cerebral infarction disease. We sequenced the Notch3 gene for 260 patients with cerebral infarction disease, 300 normal controls with old ages and 300 normal controls with younger ages, and identified the variations. The statistical analyses were conducted using Chi-Square Tests as implemented in SPSS (version 19.0). The Hardy-Weinberg equilibrium test of the population was carried out using the online software OEGE. Six variations, including rs1044116, rs1044009, rs1044006, rs10408676, rs1043996 and rs16980398 within or near the Notch3 gene, were found. The genetic heterozygosity of rs1044116, rs1044009, rs1044006, and rs1043996 was very high, whereas that of rs10408676 and rs16980398 was very low. Statistical analyses showed that rs1044009 and rs1044006 were associated with the risk of cerebral infarction disease in the Chinese Han agedness population. The SNPs rs1044009 and rs1044006 in the Notch3 gene were associated with the risk of cerebral infarction diseases in the Chinese Han agedness population.

Self-nanoemulsifying drug-delivery system for improved oral bioavailability of rosuvastatin using natural oil antihyperlipdemic.

PubMed

Abo Enin, Hadel A

2015-01-01

The aim is improving the antihyperlipidemic activity of Rosuvastatin Calcium (Rs) through improving its solubility using self-nanoemulsifying drug delivery system (SNEDDS) containing natural oil full of unsaturated fatty acid and omega 3. A 7 × 3(2) full factorial design was adopted for optimization of oil ratio, Surfactant: Co-surfactant (S:CoS) ratio and oil:S/CoS ratio. Ternary phase diagrams were constructed for optimizing the system with drug loading (10 and 20%). The optimized SNEDD systems were evaluated according to their physical evaluation and drug release. Furthermore, the anti-hyperlipidemia efficacy was compared with commercially marketed product on rates followed by clinical study. The system containing Tween 80:PEG 400 (3:1) and olive oil:garlic oil (1:1) as an oily phase has droplet size less than 100 nm, ZP (+23.43 ± 2.58 mV), PDI (<0.02) and cloud point (>90 °C). In vitro drug release studies showed remarkable enhancement of the Rs release from Rs-SNEDDS. The antihyperlipidemic effect of Rs-SNEDDS is greater than that of the commercial tablets and the pure drug on rates and in hyperlipidemic patients. Rs-SNEDDS is a promising drug delivery system for improving the drug solubility and antihyperlipidemic effect using natural oils as (olive oil and garlic oil).

Polarized light curves illuminate wind geometries in Wolf-Rayet binary stars

NASA Astrophysics Data System (ADS)

Hoffman, Jennifer L.; Fullard, Andrew G.; Nordsieck, Kenneth H.

2018-01-01

Although the majority of massive stars are affected by a companion during the course of their evolution, the role of binary systems in creating supernova and GRB progenitors is not well understood. Binaries containing Wolf-Rayet stars are particularly interesting because they may provide a mechanism for producing the rapid rotation necessary for GRB formation. However, constraining the evolutionary fate of a Wolf-Rayet binary system requires characterizing its mass loss and mass transfer, a difficult prospect in systems whose colliding winds obscure the stars and produce complicated spectral signatures.The technique of spectropolarimetry is ideally suited to studying WR binary systems because it can disentangle spectral components that take different scattering paths through a complex distribution of circumstellar material. In particular, comparing the polarization behavior as a function of orbital phase of the continuum (which arises from the stars) with that of the emission lines (which arise from the interaction region) can provide a detailed view of the wind structures in a WR+O binary and constrain the system’s mass loss and mass transfer properties.We present new continuum and line polarization curves for three WR+O binaries (WR 30, WR 47, and WR 113) obtained with the RSS spectropolarimeter at the Southern African Large Telescope. We use radiative transfer simulations to analyze the polarization curves, and discuss our interpretations in light of current models for V444 Cygni, a well-studied related binary system. Accurately characterizing the structures of the wind collision regions in these massive binaries is key to understanding their evolution and properly accounting for their contribution to the supernova (and possible GRB) progenitor population.

Uncovering the identities of compact objects in high-mass X-ray binaries and gamma-ray binaries by astrometric measurements

NASA Astrophysics Data System (ADS)

Yamaguchi, M. S.; Yano, T.; Gouda, N.

2018-03-01

We develop a method for identifying a compact object in binary systems with astrometric measurements and apply it to some binaries. Compact objects in some high-mass X-ray binaries and gamma-ray binaries are unknown, which is responsible for the fact that emission mechanisms in such systems have not yet confirmed. The accurate estimate of the mass of the compact object allows us to identify the compact object in such systems. Astrometric measurements are expected to enable us to estimate the masses of the compact objects in the binary systems via a determination of a binary orbit. We aim to evaluate the possibility of the identification of the compact objects for some binary systems. We then calculate probabilities that the compact object is correctly identified with astrometric observation (= confidence level) by taking into account a dependence of the orbital shape on orbital parameters and distributions of masses of white dwarfs, neutron stars and black holes. We find that the astrometric measurements with the precision of 70 μas for γ Cas allow us to identify the compact object at 99 per cent confidence level if the compact object is a white dwarf with 0.6 M⊙. In addition, we can identify the compact object with the precision of 10 μas at 97 per cent or larger confidence level for LS I +61° 303 and 99 per cent or larger for HESS J0632+057. These results imply that the astrometric measurements with the 10 μas precision level can realize the identification of compact objects for γ Cas, LS I +61° 303, and HESS J0632+057.

Sharing data between mobile devices, connected vehicles, and infrastructure task 3: system requirements specifications (SyRS) final.

DOT National Transportation Integrated Search

2016-07-14

This report describes the system requirements specifications (SyRS) for the use of mobile devices in a connected vehicle environment. Specifically, it defines the different types of requirements (functional, interface, performance, security, data, an...

Spectral properties of binary asteroids

NASA Astrophysics Data System (ADS)

Pajuelo, Myriam; Birlan, Mirel; Carry, Benoît; DeMeo, Francesca E.; Binzel, Richard P.; Berthier, Jérôme

2018-04-01

We present the first attempt to characterize the distribution of taxonomic class among the population of binary asteroids (15% of all small asteroids). For that, an analysis of 0.8-2.5{μ m} near-infrared spectra obtained with the SpeX instrument on the NASA/IRTF is presented. Taxonomic class and meteorite analog is determined for each target, increasing the sample of binary asteroids with known taxonomy by 21%. Most binary systems are bound in the S-, X-, and C- classes, followed by Q and V-types. The rate of binary systems in each taxonomic class agrees within uncertainty with the background population of small near-Earth objects and inner main belt asteroids, but for the C-types which are under-represented among binaries.

Accretion dynamics in pre-main sequence binaries

NASA Astrophysics Data System (ADS)

Tofflemire, B.; Mathieu, R.; Herczeg, G.; Ardila, D.; Akeson, R.; Ciardi, D.; Johns-Krull, C.

Binary stars are a common outcome of star formation. Orbital resonances, especially in short-period systems, are capable of reshaping the distribution and flows of circumstellar material. Simulations of the binary-disk interaction predict a dynamically cleared gap around the central binary, accompanied by periodic ``pulsed'' accretion events that are driven by orbital motion. To place observational constraints on the binary-disk interaction, we have conducted a long-term monitoring program tracing the time-variable accretion behavior of 9 short-period binaries. In this proceeding we present two results from our campaign: 1) the detection of periodic pulsed accretion events in DQ Tau and TWA 3A, and 2) evidence that the TWA 3A primary is the dominant accretor in the system.

RS-25 engine

NASA Image and Video Library

2012-04-10

RS-25 series rocket engine No. 2059 is unloaded and positioned at Stennis Space Center on April 10, 2012, for future testing and use on NASA's new Space Launch System. The engine was the last of 15 RS-25 engines to be delivered from NASA's Kennedy Space Center in Florida to Stennis, where all will be stored until testing begins.

Local activity determines functional connectivity in the resting human brain: a simultaneous FDG-PET/fMRI study.

PubMed

Riedl, Valentin; Bienkowska, Katarzyna; Strobel, Carola; Tahmasian, Masoud; Grimmer, Timo; Förster, Stefan; Friston, Karl J; Sorg, Christian; Drzezga, Alexander

2014-04-30

Over the last decade, synchronized resting-state fluctuations of blood oxygenation level-dependent (BOLD) signals between remote brain areas [so-called BOLD resting-state functional connectivity (rs-FC)] have gained enormous relevance in systems and clinical neuroscience. However, the neural underpinnings of rs-FC are still incompletely understood. Using simultaneous positron emission tomography/magnetic resonance imaging we here directly investigated the relationship between rs-FC and local neuronal activity in humans. Computational models suggest a mechanistic link between the dynamics of local neuronal activity and the functional coupling among distributed brain regions. Therefore, we hypothesized that the local activity (LA) of a region at rest determines its rs-FC. To test this hypothesis, we simultaneously measured both LA (glucose metabolism) and rs-FC (via synchronized BOLD fluctuations) during conditions of eyes closed or eyes open. During eyes open, LA increased in the visual system, and the salience network (i.e., cingulate and insular cortices) and the pattern of elevated LA coincided almost exactly with the spatial pattern of increased rs-FC. Specifically, the voxelwise regional profile of LA in these areas strongly correlated with the regional pattern of rs-FC among the same regions (e.g., LA in primary visual cortex accounts for ∼ 50%, and LA in anterior cingulate accounts for ∼ 20% of rs-FC with the visual system). These data provide the first direct evidence in humans that local neuronal activity determines BOLD FC at rest. Beyond its relevance for the neuronal basis of coherent BOLD signal fluctuations, our procedure may translate into clinical research particularly to investigate potentially aberrant links between local dynamics and remote functional coupling in patients with neuropsychiatric disorders.

Familial Analysis of Epistatic and Sex-Dependent Association of Genes of the Renin-Angiotensin-Aldosterone System and Blood Pressure.

PubMed

Scurrah, Katrina J; Lamantia, Angela; Ellis, Justine A; Harrap, Stephen B

2017-06-01

Renin-angiotensin-aldosterone system genes have been inconsistently associated with blood pressure, possibly because of unrecognized influences of sex-dependent genetic effects or gene-gene interactions (epistasis). We tested association of systolic blood pressure with single-nucleotide polymorphisms (SNPs) at renin ( REN ), angiotensinogen ( AGT ), angiotensin-converting enzyme ( ACE ), angiotensin II type 1 receptor ( AGTR1 ), and aldosterone synthase ( CYP11B2 ), including sex-SNP or SNP-SNP interactions. Eighty-eight tagSNPs were tested in 2872 white individuals in 809 pedigrees from the Victorian Family Heart Study using variance components models. Three SNPs (rs8075924 and rs4277404 at ACE and rs12721297 at AGTR1 ) were individually associated with lower systolic blood pressure with significant ( P <0.00076) effect sizes ≈1.7 to 2.5 mm Hg. Sex-specific associations were seen for 3 SNPs in men (rs2468523 and rs2478544 at AGT and rs11658531 at ACE ) and 1 SNP in women (rs12451328 at ACE ). SNP-SNP interaction was suggested ( P <0.005) for 14 SNP pairs, none of which had shown individual association with systolic blood pressure. Four SNP pairs were at the same gene (2 for REN , 1 for AGT , and 1 for AGTR1 ). The SNP rs3097 at CYP11B2 was represented in 5 separate pairs. SNPs at key renin-angiotensin-aldosterone system genes associate with systolic blood pressure individually in both sexes, individually in one sex only and only when combined with another SNP. Analyses that incorporate sex-dependent and epistatic effects could reconcile past inconsistencies and account for some of the missing heritability of blood pressure and are generally relevant to SNP association studies for any phenotype. © 2017 American Heart Association, Inc.

Simplified Antenna Group Determination of RS Overhead Reduced Massive MIMO for Wireless Sensor Networks.

PubMed

Lee, Byung Moo

2017-12-29

Massive multiple-input multiple-output (MIMO) systems can be applied to support numerous internet of things (IoT) devices using its excessive amount of transmitter (TX) antennas. However, one of the big obstacles for the realization of the massive MIMO system is the overhead of reference signal (RS), because the number of RS is proportional to the number of TX antennas and/or related user equipments (UEs). It has been already reported that antenna group-based RS overhead reduction can be very effective to the efficient operation of massive MIMO, but the method of deciding the number of antennas needed in each group is at question. In this paper, we propose a simplified determination scheme of the number of antennas needed in each group for RS overhead reduced massive MIMO to support many IoT devices. Supporting many distributed IoT devices is a framework to configure wireless sensor networks. Our contribution can be divided into two parts. First, we derive simple closed-form approximations of the achievable spectral efficiency (SE) by using zero-forcing (ZF) and matched filtering (MF) precoding for the RS overhead reduced massive MIMO systems with channel estimation error. The closed-form approximations include a channel error factor that can be adjusted according to the method of the channel estimation. Second, based on the closed-form approximation, we present an efficient algorithm determining the number of antennas needed in each group for the group-based RS overhead reduction scheme. The algorithm depends on the exact inverse functions of the derived closed-form approximations of SE. It is verified with theoretical analysis and simulation that the proposed algorithm works well, and thus can be used as an important tool for massive MIMO systems to support many distributed IoT devices.

Genetic variation in the endocannabinoid system and response to Cognitive Behavior Therapy for child anxiety disorders

PubMed Central

Coleman, Jonathan R. I.; Roberts, Susanna; Keers, Robert; Breen, Gerome; Bögels, Susan; Creswell, Cathy; Hudson, Jennifer L.; McKinnon, Anna; Nauta, Maaike; Rapee, Ronald M.; Schneider, Silvia; Silverman, Wendy K.; Thastum, Mikael; Waite, Polly; Wergeland, Gro Janne H.; Eley, Thalia C.

2016-01-01

Extinction learning is an important mechanism in the successful psychological treatment of anxiety. Individual differences in response and relapse following Cognitive Behavior Therapy may in part be explained by variability in the ease with which fears are extinguished or the vulnerability of these fears to re‐emerge. Given the role of the endocannabinoid system in fear extinction, this study investigates whether genetic variation in the endocannabinoid system explains individual differences in response to CBT. Children (N = 1,309) with a primary anxiety disorder diagnosis were recruited. We investigated the relationship between variation in the CNR1, CNR2, and FAAH genes and change in primary anxiety disorder severity between pre‐ and post‐treatment and during the follow‐up period in the full sample and a subset with fear‐based anxiety disorder diagnoses. Change in symptom severity during active treatment was nominally associated (P < 0.05) with two SNPs. During the follow‐up period, five SNPs were nominally associated with a poorer treatment response (rs806365 [CNR1]; rs2501431 [CNR2]; rs2070956 [CNR2]; rs7769940 [CNR1]; rs2209172 [FAAH]) and one with a more favorable response (rs6928813 [CNR1]). Within the fear‐based subset, the effect of rs806365 survived multiple testing corrections (P < 0.0016). We found very limited evidence for an association between variants in endocannabinoid system genes and treatment response once multiple testing corrections were applied. Larger, more homogenous cohorts are needed to allow the identification of variants of small but statistically significant effect and to estimate effect sizes for these variants with greater precision in order to determine their potential clinical utility. © 2016 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc. PMID:27346075

Simplified Antenna Group Determination of RS Overhead Reduced Massive MIMO for Wireless Sensor Networks

PubMed Central

2017-01-01

Massive multiple-input multiple-output (MIMO) systems can be applied to support numerous internet of things (IoT) devices using its excessive amount of transmitter (TX) antennas. However, one of the big obstacles for the realization of the massive MIMO system is the overhead of reference signal (RS), because the number of RS is proportional to the number of TX antennas and/or related user equipments (UEs). It has been already reported that antenna group-based RS overhead reduction can be very effective to the efficient operation of massive MIMO, but the method of deciding the number of antennas needed in each group is at question. In this paper, we propose a simplified determination scheme of the number of antennas needed in each group for RS overhead reduced massive MIMO to support many IoT devices. Supporting many distributed IoT devices is a framework to configure wireless sensor networks. Our contribution can be divided into two parts. First, we derive simple closed-form approximations of the achievable spectral efficiency (SE) by using zero-forcing (ZF) and matched filtering (MF) precoding for the RS overhead reduced massive MIMO systems with channel estimation error. The closed-form approximations include a channel error factor that can be adjusted according to the method of the channel estimation. Second, based on the closed-form approximation, we present an efficient algorithm determining the number of antennas needed in each group for the group-based RS overhead reduction scheme. The algorithm depends on the exact inverse functions of the derived closed-form approximations of SE. It is verified with theoretical analysis and simulation that the proposed algorithm works well, and thus can be used as an important tool for massive MIMO systems to support many distributed IoT devices. PMID:29286339

Genetic polymorphism of matrix metalloproteinase-1 and coronary artery disease susceptibility: a case-control study in a Han Chinese population.

PubMed

Qintao, Cui; Yan, Li; Changhong, Duan; Xiaoliang, Guo; Xiaochen, Liu

2014-12-01

Coronary artery disease (CAD) receives intensive research due to its high incidence and severe impact on the quality of life. One member of the matrix metalloproteinases (MMPs), MMP-1, has been reported to be associated with CAD. To identify the markers contributing to the genetic susceptibility to CAD, nine single-nucleotide polymorphisms (rs1799750, rs498186, rs475007, rs514921, rs494379, rs996999, rs2071232, rs1938901, and rs2239008) throughout the MMP-1 gene were genotyped using MALDI-TOF within the MassARRAY system, and the allele and genotype distributions were compared between 438 healthy controls and 411 patients with CAD from a Chinese Han population. The analysis revealed a weak association between the rs1799750 (in the promoter region) genotype distribution and CAD (p=0.022). An increased risk of CAD was significantly associated with the 2G allele of rs1799750 (p=0.005, odds ratio=1.329, 95% confidence interval=1.090-1.620, after Bonferroni corrections). Strong linkage disequilibrium was observed in three blocks (D'>0.9). Significantly more C-2G (rs498186-rs1799750) haplotypes (p=0.001 after Bonferroni corrections) were found in CAD subjects. These findings point to a role for the polymorphism in the MMP-1 promoter in CAD among a Han Chinese population and may be informative for future genetic or biological studies on CAD.

The Functional Integration in the Sensory-Motor System Predicts Aging in Healthy Older Adults.

PubMed

He, Hui; Luo, Cheng; Chang, Xin; Shan, Yan; Cao, Weifang; Gong, Jinnan; Klugah-Brown, Benjamin; Bobes, Maria A; Biswal, Bharat; Yao, Dezhong

2016-01-01

Healthy aging is typically accompanied by a decrease in the motor capacity. Although the disrupted neural representations and performance of movement have been observed in older age in previous studies, the relationship between the functional integration of sensory-motor (SM) system and aging could be further investigated. In this study, we examine the impact of healthy aging on the resting-state functional connectivity (rsFC) of the SM system, and investigate as to how aging is affecting the rsFC in SM network. The SM network was identified and evaluated in 52 healthy older adults and 51 younger adults using two common data analytic approaches: independent component analysis and seed-based functional connectivity (seed at bilateral M1 and S1). We then evaluated whether the altered rsFC of the SM network could delineate trajectories of the age of older adults using a machine learning methodology. Compared with the younger adults, the older demonstrated reduced functional integration with increasing age in the mid-posterior insula of SM network and increased rsFC among the sensorimotor cortex. Moreover, the reduction in the rsFC of mid-posterior insula is associated with the age of older adults. Critically, the analysis based on two-aspect connectivity-based prediction frameworks revealed that the age of older adults could be reliably predicted by this reduced rsFC. These findings further indicated that healthy aging has a marked influence on the SM system that would be associated with a reorganization of SM system with aging. Our findings provide further insight into changes in sensorimotor function in the aging brain.

The Eclipsing Binary On-Line Atlas (EBOLA)

NASA Astrophysics Data System (ADS)

Bradstreet, D. H.; Steelman, D. P.; Sanders, S. J.; Hargis, J. R.

2004-05-01

In conjunction with the upcoming release of \\it Binary Maker 3.0, an extensive on-line database of eclipsing binaries is being made available. The purposes of the atlas are: \\begin {enumerate} Allow quick and easy access to information on published eclipsing binaries. Amass a consistent database of light and radial velocity curve solutions to aid in solving new systems. Provide invaluable querying capabilities on all of the parameters of the systems so that informative research can be quickly accomplished on a multitude of published results. Aid observers in establishing new observing programs based upon stars needing new light and/or radial velocity curves. Encourage workers to submit their published results so that others may have easy access to their work. Provide a vast but easily accessible storehouse of information on eclipsing binaries to accelerate the process of understanding analysis techniques and current work in the field. \\end {enumerate} The database will eventually consist of all published eclipsing binaries with light curve solutions. The following information and data will be supplied whenever available for each binary: original light curves in all bandpasses, original radial velocity observations, light curve parameters, RA and Dec, V-magnitudes, spectral types, color indices, periods, binary type, 3D representation of the system near quadrature, plots of the original light curves and synthetic models, plots of the radial velocity observations with theoretical models, and \\it Binary Maker 3.0 data files (parameter, light curve, radial velocity). The pertinent references for each star are also given with hyperlinks directly to the papers via the NASA Abstract website for downloading, if available. In addition the Atlas has extensive searching options so that workers can specifically search for binaries with specific characteristics. The website has more than 150 systems already uploaded. The URL for the site is http://ebola.eastern.edu/.

Binary Systems and the Initial Mass Function

NASA Astrophysics Data System (ADS)

Malkov, O. Yu.

2017-07-01

In the present paper we discuss advantages and disadvantages of binary stars, which are important for star formation history determination. We show that to make definite conclusions of the initial mass function shape, it is necessary to study binary population well enough to correct the luminosity function for unresolved binaries; to construct the mass-luminosity relation based on wide binaries data, and to separate observational mass functions of primaries, of secondaries, and of unresolved binaries.

Comparison of two gas chromatograph models and analysis of binary data

NASA Technical Reports Server (NTRS)

Keba, P. S.; Woodrow, P. T.

1972-01-01

The overall objective of the gas chromatograph system studies is to generate fundamental design criteria and techniques to be used in the optimum design of the system. The particular tasks currently being undertaken are the comparison of two mathematical models of the chromatograph and the analysis of binary system data. The predictions of two mathematical models, an equilibrium absorption model and a non-equilibrium absorption model exhibit the same weaknesses in their inability to predict chromatogram spreading for certain systems. The analysis of binary data using the equilibrium absorption model confirms that, for the systems considered, superposition of predicted single component behaviors is a first order representation of actual binary data. Composition effects produce non-idealities which limit the rigorous validity of superposition.

Apical Transportation, Centering Ability, and Cleaning Effectiveness of Reciprocating Single-file System Associated with Different Glide Path Techniques.

PubMed

de Carvalho, Guilherme Moreira; Sponchiado Junior, Emílio Carlos; Garrido, Angela Delfina Bittencourt; Lia, Raphael Carlos Comelli; Garcia, Lucas da Fonseca Roberti; Marques, André Augusto Franco

2015-12-01

The aim of this study was to evaluate the apical transportation, the centering ability, and the cleaning effectiveness of a reciprocating single-file system associated to different glide path techniques. The mesial root canals of 52 mandibular molars were randomly distributed into 4 groups (n = 13) according to the different glide path techniques used before biomechanical preparation with Reciproc System (RS): KF/RS (sizes 10 and 15 K-files), NGP/RS (no glide path, only reciprocating system), PF/RS (sizes 13, 16, and 19 PathFile instruments), and NP (no preparation). Cone-beam computed tomography analysis was performed before and after instrumentation for apical third images acquisition. Apical transportation and its direction were evaluated by using the formula D = (X1 - X2) - (Y1 - Y2), and the centering ability was analyzed by the formula CC = (X1 - X2/Y1 - Y2 or Y1 - Y2/X1 - X2). The samples were submitted to histologic processing and analyzed under a digital microscope for debris quantification. The values were statistically analyzed (Kruskal-Wallis, the Dunn multiple comparisons test, P < .05). All groups had similar apical transportation values, with no significant difference among them (P > .05). Groups had a tendency toward transportation in the mesial direction. No technique had perfect centering ability (=1.0), with no significant difference among them. KF/RS had larger amount of debris, with statistically significant difference in comparison with NGP/RS (P > .05). The different glide path techniques promoted minimal apical transportation, and the reciprocating single-file system tested remained relatively centralized within the root canal. Also, the different techniques interfered in the cleaning effectiveness of the reciprocating system. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Physical exercise counteracts genetic susceptibility to depression.

PubMed

Haslacher, Helmuth; Michlmayr, Matthias; Batmyagmar, Delgerdalai; Perkmann, Thomas; Ponocny-Seliger, Elisabeth; Scheichenberger, Vanessa; Pilger, Alexander; Dal-Bianco, Peter; Lehrner, Johann; Pezawas, Lukas; Wagner, Oswald; Winker, Robert

2015-01-01

Depression is a highly prevalent disorder in elderly individuals. A genetic variant (rs6265) of the brain-derived neurotrophic factor (BDNF) impacting on emotion processing is known to increase the risk for depression. We aim to investigate whether intensive endurance sports might attenuate this genetic susceptibility in a cohort of elderly marathon athletes. Fifty-five athletes and 58 controls were included. rs6265 of the BDNF gene was genotyped by the TaqMan method. Depressive symptoms were assessed by standardized self-rating tests (BDI = Beck Depression Inventory, GDS = Geriatric Depression Scale). In multivariable analysis of BDI and GDS scores, the interaction between group (athletes vs. controls) and genotypes ([C];[C] vs. [C];[T] + [T];[T]) was found to be statistically significant (BDI: p = 0.027, GDS: p = 0.013). Among [C];[C] carriers, merely controls had an increased relative risk of 3.537 (95% CI = 1.276-9.802) of achieving a subclinical depression score ≥10 on the BDI. There was no such effect in carriers of the [T] allele. In a multivariable binary logistic regression, genetic information, group (athletes/controls), but no information on rs6265 allele carrier status presented as a significant predictor of BDI scores ≥10. Physical exercise positively affects BDNF effects on mood. Since 66Met BDNF secretion is impaired, this effect seems to be much stronger in [C];[C] homozygous individuals expressing the 66Val variant. This confirms that genetic susceptibility to depressive symptoms can indeed be influenced by endurance sports in elderly people. © 2015 S. Karger AG, Basel.

Using Model Point Spread Functions to Identifying Binary Brown Dwarf Systems

NASA Astrophysics Data System (ADS)

Matt, Kyle; Stephens, Denise C.; Lunsford, Leanne T.

2017-01-01

A Brown Dwarf (BD) is a celestial object that is not massive enough to undergo hydrogen fusion in its core. BDs can form in pairs called binaries. Due to the great distances between Earth and these BDs, they act as point sources of light and the angular separation between binary BDs can be small enough to appear as a single, unresolved object in images, according to Rayleigh Criterion. It is not currently possible to resolve some of these objects into separate light sources. Stephens and Noll (2006) developed a method that used model point spread functions (PSFs) to identify binary Trans-Neptunian Objects, we will use this method to identify binary BD systems in the Hubble Space Telescope archive. This method works by comparing model PSFs of single and binary sources to the observed PSFs. We also use a method to compare model spectral data for single and binary fits to determine the best parameter values for each component of the system. We describe these methods, its challenges and other possible uses in this poster.

IL-23R mutation is associated with ulcerative colitis: A systemic review and meta-analysis.

PubMed

Peng, Ling-Long; Wang, Ying; Zhu, Feng-Ling; Xu, Wang-Dong; Ji, Xue-Lei; Ni, Jing

2017-01-17

Since a genome-wide association study revealed that Interleukin-23 receptor (IL-23R) gene is a candidate gene for Ulcerative Colitis (UC), many studies have investigated the association between the IL-23R polymorphisms and UC. However, the results were controversial. The aim of the study was to determine whether the IL-23R polymorphisms confer susceptibility to UC. A systematic literature search was carried out to identify all potentially relevant studies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the strength of association. A total of 33 studies in 32 articles, including 10,527 UC cases and 15,142 healthy controls, were finally involved in the meta-analysis. Overall, a significant association was found between all UC cases and the rs11209026A allele (OR = 0.665, 95% CI = 0.604~0.733, P < 0.001). Similarly, meta-analyses of the rs7517847, rs1004819, rs10889677, rs2201841, rs11209032, rs1495965, rs1343151 and rs11465804 polymorphisms also indicated significant association with all UC (all P < 0.05). Stratification by ethnicity revealed that the rs11209026, rs7517847, rs10889677, rs2201841 andrs11465804 polymorphisms were associated with UC in the Caucasian group, but not in Asians, while the rs1004819 and rs11209032 polymorphisms were found to be related to UC for both Caucasian and Asian groups. However, subgroup analysis failed to unveil any association between the rs1495965 and rs1343151 polymorphisms and UC in Caucasians or Asians. The meta-analysis suggests significant association between IL-23R polymorphisms and UC, especially in Caucasians.

IL-23R mutation is associated with ulcerative colitis: A systemic review and meta-analysis

PubMed Central

Peng, Ling-Long; Wang, Ying; Zhu, Feng-Ling; Xu, Wang-Dong; Ji, Xue-Lei; Ni, Jing

2017-01-01

Objectives Since a genome-wide association study revealed that Interleukin-23 receptor (IL-23R) gene is a candidate gene for Ulcerative Colitis (UC), many studies have investigated the association between the IL-23R polymorphisms and UC. However, the results were controversial. The aim of the study was to determine whether the IL-23R polymorphisms confer susceptibility to UC. Methods A systematic literature search was carried out to identify all potentially relevant studies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the strength of association. Results A total of 33 studies in 32 articles, including 10,527 UC cases and 15,142 healthy controls, were finally involved in the meta-analysis. Overall, a significant association was found between all UC cases and the rs11209026A allele (OR = 0.665, 95% CI = 0.604~0.733, P < 0.001). Similarly, meta-analyses of the rs7517847, rs1004819, rs10889677, rs2201841, rs11209032, rs1495965, rs1343151 and rs11465804 polymorphisms also indicated significant association with all UC (all P < 0.05). Stratification by ethnicity revealed that the rs11209026, rs7517847, rs10889677, rs2201841 andrs11465804 polymorphisms were associated with UC in the Caucasian group, but not in Asians, while the rs1004819 and rs11209032 polymorphisms were found to be related to UC for both Caucasian and Asian groups. However, subgroup analysis failed to unveil any association between the rs1495965 and rs1343151 polymorphisms and UC in Caucasians or Asians. Conclusions The meta-analysis suggests significant association between IL-23R polymorphisms and UC, especially in Caucasians. PMID:27902482

Hydrodynamical processes in coalescing binary stars

NASA Astrophysics Data System (ADS)

Lai, Dong

1994-01-01

Coalescing neutron star binaries are considered to be the most promising sources of gravitational waves that could be detected by the planned laser-interferometer LIGO/VIRGO detectors. Extracting gravity wave signals from noisy data requires accurate theoretical waveforms in the frequency range 10-1000 Hz end detailed understanding of the dynamics of the binary orbits. We investigate the quasi-equilibrium and dynamical tidal interactions in coalescing binary stars, with particular focus on binary neutron stars. We develop a new formalism to study the equilibrium and dynamics of fluid stars in binary systems. The stars are modeled as compressible ellipsoids, and satisfy polytropic equation of state. The hydrodynamic equations are reduced to a set of ordinary differential equations for the evolution of the principal axes and other global quantities. The equilibrium binary structure is determined by a set of algebraic equations. We consider both synchronized and nonsynchronized systems, obtaining the generalizations to compressible fluid of the classical results for the ellipsoidal binary configurations. Our method can be applied to a wide variety of astrophysical binary systems containing neutron stars, white dwarfs, main-sequence stars and planets. We find that both secular and dynamical instabilities can develop in close binaries. The quasi-static (secular) orbital evolution, as well as the dynamical evolution of binaries driven by viscous dissipation and gravitational radiation reaction are studied. The development of the dynamical instability accelerates the binary coalescence at small separation, leading to appreciable radial infall velocity near contact. We also study resonant excitations of g-mode oscillations in coalescing binary neutron stars. A resonance occurs when the frequency of the tidal driving force equals one of the intrinsic g-mode frequencies. Using realistic microscopic nuclear equations of state, we determine the g-modes in a cold neutron atar. Resonant excitations of these g-modes during the last few minutes of the binary coalescence result in energy transfer and angular momentum transfer from the binary orbit to the neutron star. Because of the weak coupling between the g-modes and the tidal potential, the induced orbital phase errors due to resonances are small. However, resonant excitations of the g-modes play an important role in the tidal heating of binary neutron stars.

Mass loss from interacting close binary systems

NASA Technical Reports Server (NTRS)

Plavec, M. J.

1981-01-01

The three well-defined classes of evolved binary systems that show evidence of present and/or past mass loss are the cataclysmic variables, the Algols, and Wolf-Rayet stars. It is thought that the transformation of supergiant binary systems into the very short-period cataclysmic variables must have been a complex process. The new evidence that has recently been obtained from the far ultraviolet spectra that a certain subclass of the Algols (the Serpentids) are undergoing fairly rapid evolution is discussed. It is thought probable that the remarkable mass outflow observed in them is connected with a strong wind powered by accretion. The origin of the circumbinary clouds or flat disks that probably surround many strongly interacting binaries is not clear. Attention is also given to binary systems with hot white dwarf or subdwarf components, such as the symbiotic objects and the BQ stars; it is noted that in them both components may be prone to an enhanced stellar wind.

A New Equilibrium State for Singly Synchronous Binary Asteroids

NASA Astrophysics Data System (ADS)

Golubov, Oleksiy; Unukovych, Vladyslav; Scheeres, Daniel J.

2018-04-01

The evolution of rotation states of small asteroids is governed by the Yarkovsky–O’Keefe–Radzievskii–Paddack (YORP) effect, nonetheless some asteroids can stop their YORP evolution by attaining a stable equilibrium. The same is true for binary asteroids subjected to the binary YORP (BYORP) effect. Here we discuss a new type of equilibrium that combines these two, which is possible in a singly synchronous binary system. This equilibrium occurs when the normal YORP, the tangential YORP, and the BYORP compensate each other, and tidal torques distribute the angular momentum between the components of the system and dissipate energy. If unperturbed, such a system would remain singly synchronous in perpetuity with constant spin and orbit rates, as the tidal torques dissipate the incoming energy from impinging sunlight at the same rate. The probability of the existence of this kind of equilibrium in a binary system is found to be on the order of a few percent.

The Evolution of Compact Binary Star Systems.

PubMed

Postnov, Konstantin A; Yungelson, Lev R

2014-01-01

We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Mergings of compact-star binaries are expected to be the most important sources for forthcoming gravitational-wave (GW) astronomy. In the first part of the review, we discuss observational manifestations of close binaries with NS and/or BH components and their merger rate, crucial points in the formation and evolution of compact stars in binary systems, including the treatment of the natal kicks, which NSs and BHs acquire during the core collapse of massive stars and the common envelope phase of binary evolution, which are most relevant to the merging rates of NS-NS, NS-BH and BH-BH binaries. The second part of the review is devoted mainly to the formation and evolution of binary WDs and their observational manifestations, including their role as progenitors of cosmologically-important thermonuclear SN Ia. We also consider AM CVn-stars, which are thought to be the best verification binary GW sources for future low-frequency GW space interferometers.

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

Dumbser, Michael, E-mail: michael.dumbser@unitn.it; Balsara, Dinshaw S., E-mail: dbalsara@nd.edu

In this paper a new, simple and universal formulation of the HLLEM Riemann solver (RS) is proposed that works for general conservative and non-conservative systems of hyperbolic equations. For non-conservative PDE, a path-conservative formulation of the HLLEM RS is presented for the first time in this paper. The HLLEM Riemann solver is built on top of a novel and very robust path-conservative HLL method. It thus naturally inherits the positivity properties and the entropy enforcement of the underlying HLL scheme. However, with just the slight additional cost of evaluating eigenvectors and eigenvalues of intermediate characteristic fields, we can represent linearlymore » degenerate intermediate waves with a minimum of smearing. For conservative systems, our paper provides the easiest and most seamless path for taking a pre-existing HLL RS and quickly and effortlessly converting it to a RS that provides improved results, comparable with those of an HLLC, HLLD, Osher or Roe-type RS. This is done with minimal additional computational complexity, making our variant of the HLLEM RS also a very fast RS that can accurately represent linearly degenerate discontinuities. Our present HLLEM RS also transparently extends these advantages to non-conservative systems. For shallow water-type systems, the resulting method is proven to be well-balanced. Several test problems are presented for shallow water-type equations and two-phase flow models, as well as for gas dynamics with real equation of state, magnetohydrodynamics (MHD & RMHD), and nonlinear elasticity. Since our new formulation accommodates multiple intermediate waves and has a broader applicability than the original HLLEM method, it could alternatively be called the HLLI Riemann solver, where the “I” stands for the intermediate characteristic fields that can be accounted for. -- Highlights: •New simple and general path-conservative formulation of the HLLEM Riemann solver. •Application to general conservative and non-conservative hyperbolic systems. •Inclusion of sub-structure and resolution of intermediate characteristic fields. •Well-balanced for single- and two-layer shallow water equations and multi-phase flows. •Euler equations with real equation of state, MHD equations, nonlinear elasticity.« less

Stability of binaries. Part II: Rubble-pile binaries

NASA Astrophysics Data System (ADS)

Sharma, Ishan

2016-10-01

We consider the stability of the binary asteroids whose members are granular aggregates held together by self-gravity alone. A binary is said to be stable whenever both its members are orbitally and structurally stable to both orbital and structural perturbations. To this end, we extend the stability analysis of Sharma (Sharma [2015] Icarus, 258, 438-453), that is applicable to binaries with rigid members, to the case of binary systems with rubble members. We employ volume averaging (Sharma et al. [2009] Icarus, 200, 304-322), which was inspired by past work on elastic/fluid, rotating and gravitating ellipsoids. This technique has shown promise when applied to rubble-pile ellipsoids, but requires further work to settle some of its underlying assumptions. The stability test is finally applied to some suspected binary systems, viz., 216 Kleopatra, 624 Hektor and 90 Antiope. We also see that equilibrated binaries that are close to mobilizing their maximum friction can sustain only a narrow range of shapes and, generally, congruent shapes are preferred.

1E 1048.5 + 5421 - A new 114 minute AM Herculis binary

NASA Technical Reports Server (NTRS)

Morris, Simon L.; Schmidt, Gary D.; Liebert, James; Gioia, Isabella M.; Maccacaro, Tommaso

1987-01-01

The discovery of a new AM Herculis binary system, found as a serendipitous Einstein X-ray source, is described. Like the previously discovered mass-transfer binaries involving synchronously rotating magnetic white-dwarf primaries, the system exhibits strong circular polarization, X-ray and optical continuum variations, and optical emission lines, all of which seem to be modulated with these binary periods of 114.5 + or - 0.2 minutes. Although all data are not concurrent, the new system appears to possess the highest ratio of F(x)/F(opt) yet found for an AM Her system. The surprising accumulation of AM Her variables with periods near 114 minute is commented on.

A photometric analysis of the neglected EW-type binary V336 TrA

NASA Astrophysics Data System (ADS)

Kriwattanawong, W.; Sarotsakulchai, T.; Maungkorn, S.; Reichart, D. E.; Haislip, J. B.; Kouprianov, V. V.; LaCluyze, A. P.; Moore, J. P.

2018-05-01

This study presents an analysis of photometric light curves and absolute parameters for the EW-type binary V336 TrA. VRI imaging observations were taken in 2013 by using the robotic telescopes PROMPT 4 and PROMPT 5 at Cerro Tololo Inter-American Observatory (CTIO), Chile. The observed light curves were fitted by using the Wilson-Devinney method. The results showed that V336 TrA is a W-type contact binary with a mass ratio of q = 1.396. The binary is a weak contact system with a fill-out factor of f = 15.69%. The system contains components with masses of 0.653 M⊙ and 0.912 M⊙ for the hotter and the cooler, respectively. The location of the secondary (less massive) component on the log M - log L diagram was found to be near the TAMS. The component has evolved to be oversize and overluminous. The orbital angular momentum of the binary was found to be log Jo = 51.61 cgs, less than all detached systems for same mass. The system has undergone angular momentum and/or mass loss, during the binary evolution from the detached to contact system.

Binary Number System Training for Graduate Foreign Students at New York Institute of Technology.

ERIC Educational Resources Information Center

Sudsataya, Nuntawun

This thesis describes the design, development, implementation, and evaluation of a training module to instruct graduate foreign students to learn the representation of the binary system and the method of decimal-binary conversion. The designer selected programmed instruction as the method of instruction and used the "lean" approach to…

NASA Tests 2nd RS-25 Flight Engine for Space Launch System

NASA Image and Video Library

2018-01-16

On Jan. 16, 2018, engineers at NASA’s Stennis Space Center in Mississippi conducted a certification test of another RS-25 engine flight controller on the A-1 Test Stand at Stennis Space Center. The 365-second, full-duration test came a month after the space agency capped a year of RS-25 testing with a flight controller test in mid-December. For the “green run” test the flight controller was installed on RS-25 developmental engine E0528 and fired just as during an actual launch. Once certified, the flight controller will be removed and installed on a flight engine for use by NASA’s new deep-space rocket, the Space Launch System (SLS).

Confidential close call reporting system (C3RS) lessons learned team baseline phased report

DOT National Transportation Integrated Search

2015-05-08

The Federal Railroad Administration (FRA) has established a program called the Confidential Close Call Reporting System : (C3RS), which allows events to be reported anonymously and dealt with non-punitively and without fear or reprisal through : stru...

Confidential close call reporting system (C3RS) lessons learned team baseline phase report.

DOT National Transportation Integrated Search

2015-05-01

The Federal Railroad Administration (FRA) has established a program called the Confidential Close Call Reporting System : (C3 : RS), which allows events to be reported anonymously and dealt with non-punitively and without fear or reprisal through : s...

New prospects for observing and cataloguing exoplanets in well-detached binaries

NASA Astrophysics Data System (ADS)

Schwarz, R.; Funk, B.; Zechner, R.; Bazsó, Á.

2016-08-01

This paper is devoted to study the circumstances favourable to detect circumstellar and circumbinary planets in well-detached binary-star systems using eclipse timing variations (ETVs). We investigated the dynamics of well-detached binary star systems with a star separation from 0.5 to 3 au, to determine the probability of the detection of such variations with ground-based telescopes and space telescopes (like former missions CoRoT and Kepler and future space missions Plato, Tess and Cheops). For the chosen star separations both dynamical configurations (circumstellar and circumbinary) may be observable. We performed numerical simulations by using the full three-body problem as dynamical model. The dynamical stability and the ETVs are investigated by computing ETV maps for different masses of the secondary star and the exoplanet (Earth, Neptune and Jupiter size). In addition we changed the planet's and binary's eccentricities. We conclude that many amplitudes of ETVs are large enough to detect exoplanets in binary-star systems. As an application, we prepared statistics of the catalogue of exoplanets in binary star systems which we introduce in this article and compared the statistics with our parameter-space which we used for our calculations. In addition to these statistics of the catalogue we enlarged them by the investigation of well-detached binary star systems from several catalogues and discussed the possibility of further candidates.

Modeling tools for an Integrated River-Delta-Sea system investigation: the Pan-European Research Infrastructure DANUBIUS-RI philosophy

NASA Astrophysics Data System (ADS)

Umgiesser, Georg; Bellafiore, Debora; De Pascalis, Francesca; Icke, Joost; Stanica, Adrian

2017-04-01

The DANUBIUS Research Infrastructure (DANUBIUS-RI) is a new initiative to address the challenges and opportunities of research on large river- sea (RS) systems. DANUBIUS-RI is a distributed pan-European RI that will provide a platform for interdisciplinary research. It will deal with RS investigation through facilities and expertise from a large number of European institutions becoming a 'one-stop shop' for knowledge exchange in managing RS systems, ranging from freshwater to marine research. Globally, RS systems are complex and dynamic, with huge environmental, social and economic value. They are poorly understood but under increasing pressure through pollution, hydraulic engineering, water supply, energy, flood control and erosion. RS systems in Europe are among the most impacted globally, after centuries of industrialisation, urbanisation and agricultural intensification. Improved understanding is essential to avoid irreversible degradation and for restoration. DANUBIUS-RI will provide, among a number of other facilities concerning observations, analyses, impacts' evaluation, a modeling node that will provide integrated up-to-date tools, at locations of high scientific importance and opportunity, covering the RS systems - from source (upper parts of rivers - mountain lakes) to the transition with coastal seas. Modeling will be one of the major services provided by DANUBIUS-RI, relying on the inputs from the whole RI. RS systems are challenging from a modelling point of view, because of the complex morphology and the wide temporal and spatial range of processes occurring. Scale interaction plays a central role, considering the different hydro-eco-morphological processes on the large (basin) and small (local, coast, rivers, lagoons) scale. Currently, different model applications are made for the different geographical domains, and also for subsets of the processes. For instance there are separate models for rainfall runoff in the catchment, a sewer model for the urban area and a water quality model for the sea. Obviously, the subsystems interact with each other: water flows from the catchments to the rivers and into the sea. The rainfall runoff from the upstream catchment picks up the emissions and the river transports the substances via the estuaries to the sea. In the sea, the substances interact with the marine ecosystem. The challenge for the modeling of river - sea systems is (1) the integration of models for the geographical domains, (2) the integration of physical, chemical, ecological and socio-economical processes and (3) the exploration and application of new data sources. The modeling strategy that is starting to be shaped within DANUBIUS-RI will provide relocatable tools and suitable techniques to be efficiently applied in the different geographical areas, integrating the DANUBIUS-RI modeling skills and showing high performance modeling solutions for the investigation of RS systems. Moreover, a technological advanced platform for modeling services, in terms of software and shared data will be created. A preliminary sketch of the organization of the DANUBIUS modeling node and examples of field of action for RS systems investigation will be provided.

Population trends of binary near-Earth asteroids based on radar and lightcurves observations

NASA Astrophysics Data System (ADS)

Brozovic, Marina; Benner, Lance A. M.; Naidu, Shantanu P.; Taylor, Patrick A.; Busch, Michael W.; Margot, Jean-Luc; Nolan, Michael C.; Howell, Ellen S.; Springmann, Alessondra; Giorgini, Jon D.; Shepard, Michael K.; Magri, Christopher; Richardson, James E.; Rivera-Valentin, Edgard G.; Rodriguez-Ford, Linda A.; Zambrano Marin, Luisa Fernanda

2016-10-01

The Arecibo and Goldstone planetary radars are invaluable instruments for the discovery and characterization of binary and triple asteroids in the near-Earth asteroid (NEA) population. To date, 41 out of 56 known binaries and triples (~73% of the objects) have been discovered by radar and 49 of these multiple systems have been detected by radar. Their absolute magnitudes range from 12.4 for (1866) Sisyphus to 22.6 for 2015 TD144 and have a mean and rms dispersion of 18.1+-2.0. There is a pronounced decrease in the abundance of binaries for absolute magnitudes H>20. One of the smallest binaries, 1994 CJ1, with an absolute magnitude H=21.4, is also the most accessible binary for a spacecraft rendezvous. Among 365 NEAs with H<22 (corresponding to diameters larger than ~ 140 m) detected by radar since 1999, ~13% have at least one companion. Two triple systems are known, (15391) 2001 SN263 and (136617) 1994 CC, but this is probably an underestimate due to low signal to noise ratios (SNRs) for many of the binary radar detections. Taxonomic classes have been reported for 41 out of 56 currently known multiple systems and some trends are starting to emerge: at least 50% of multiple asteroid systems are S, Sq, Q, or Sk, and at least 20% are optically dark (C, B, P, or U). Thirteen V-class NEAs have been observed by radar and six of them are binaries. Curiously, a comparable number of E-class objects have been detected by radar, but none is known to be a binary.

Genetic variation in Aquaporin-4 moderates the relationship between sleep and brain Aβ-amyloid burden.

PubMed

Rainey-Smith, Stephanie R; Mazzucchelli, Gavin N; Villemagne, Victor L; Brown, Belinda M; Porter, Tenielle; Weinborn, Michael; Bucks, Romola S; Milicic, Lidija; Sohrabi, Hamid R; Taddei, Kevin; Ames, David; Maruff, Paul; Masters, Colin L; Rowe, Christopher C; Salvado, Olivier; Martins, Ralph N; Laws, Simon M

2018-02-26

The glymphatic system is postulated to be a mechanism of brain Aβ-amyloid clearance and to be most effective during sleep. Ablation of the astrocytic end-feet expressed water-channel protein, Aquaporin-4, in mice, results in impairment of this clearance mechanism and increased brain Aβ-amyloid deposition, suggesting that Aquaporin-4 plays a pivotal role in glymphatic function. Currently there is a paucity of literature regarding the impact of AQP4 genetic variation on sleep, brain Aβ-amyloid burden and their relationship to each other in humans. To address this a cross-sectional observational study was undertaken in cognitively normal older adults from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study. Genetic variants in AQP4 were investigated with respect to self-reported Pittsburgh Sleep Quality Index sleep parameters, positron emission tomography derived brain Aβ-amyloid burden and whether these genetic variants moderated the sleep-Aβ-amyloid burden relationship. One AQP4 variant, rs72878776, was associated with poorer overall sleep quality, while several SNPs moderated the effect of sleep latency (rs491148, rs9951307, rs7135406, rs3875089, rs151246) and duration (rs72878776, rs491148 and rs2339214) on brain Aβ-amyloid burden. This study suggests that AQP4 genetic variation moderates the relationship between sleep and brain Aβ-amyloid burden, which adds weight to the proposed glymphatic system being a potential Aβ-amyloid clearance mechanism and suggests that AQP4 genetic variation may impair this function. Further, AQP4 genetic variation should be considered when interpreting sleep-Aβ relationships.

Possible association of VISA gene polymorphisms with susceptibility to systemic lupus erythematosus in Chinese population.

PubMed

Liu, Xiaowen; Jiao, Yulian; Wen, Xin; Wang, Laicheng; Ma, Chunyan; Gao, Xuejun; Chen, Zi-Jiang; Zhao, Yueran

2011-10-01

Virus-induced signaling adapter (VISA), an important adaptor protein linking both RIG-I and MDA-5 to downstream signaling events, may mediates the activation of NF kappaB and IRFs and the induction of type I IFN. As the evidence has showed that Toll-like receptors (TLRs), I-IFN and IFN-inducible genes contribute to the pathogenesis of systemic lupus erythematosus (SLE), the aim of the current study was to investigate the possible associations between the VISA gene and SLE. Four single nucleotide polymorphisms (SNPs), rs17857295, rs2326369, rs7262903, and rs7269320, in VISA gene were genotyped in 123 SLE patients and 95 healthy controls. Genotyping was performed using direct sequencing the purified PCR products. Associations were analyzed by using the chi-square test and Fisher's exact test. Haplotype analysis was performed using haploview and PHASE2.1. None of the four SNPs was found to be associated with SLE. The four-SNPs haplotype analysis showed different effect between cases and controls. While the SNPs, rs17857295 and rs2326369, were found to be associated with the renal nephritis and arthritis of SLE patient, respectively. The SNPs rs7269320 showed associations with different manifestations. Our data reveal that polymorphisms in the VISA gene may be related to disease susceptibility and manifestations of SLE.

A massive binary black-hole system in OJ 287 and a test of general relativity.

PubMed

Valtonen, M J; Lehto, H J; Nilsson, K; Heidt, J; Takalo, L O; Sillanpää, A; Villforth, C; Kidger, M; Poyner, G; Pursimo, T; Zola, S; Wu, J-H; Zhou, X; Sadakane, K; Drozdz, M; Koziel, D; Marchev, D; Ogloza, W; Porowski, C; Siwak, M; Stachowski, G; Winiarski, M; Hentunen, V-P; Nissinen, M; Liakos, A; Dogru, S

2008-04-17

Tests of Einstein's general theory of relativity have mostly been carried out in weak gravitational fields where the space-time curvature effects are first-order deviations from Newton's theory. Binary pulsars provide a means of probing the strong gravitational field around a neutron star, but strong-field effects may be best tested in systems containing black holes. Here we report such a test in a close binary system of two candidate black holes in the quasar OJ 287. This quasar shows quasi-periodic optical outbursts at 12-year intervals, with two outburst peaks per interval. The latest outburst occurred in September 2007, within a day of the time predicted by the binary black-hole model and general relativity. The observations confirm the binary nature of the system and also provide evidence for the loss of orbital energy in agreement (within 10 per cent) with the emission of gravitational waves from the system. In the absence of gravitational wave emission the outburst would have happened 20 days later.

Synergies in Astrometry: Predicting Navigational Error of Visual Binary Stars

NASA Astrophysics Data System (ADS)

Gessner Stewart, Susan

2015-08-01

Celestial navigation can employ a number of bright stars which are in binary systems. Often these are unresolved, appearing as a single, center-of-light object. A number of these systems are, however, in wide systems which could introduce a margin of error in the navigation solution if not handled properly. To illustrate the importance of good orbital solutions for binary systems - as well as good astrometry in general - the relationship between the center-of-light versus individual catalog position of celestial bodies and the error in terrestrial position derived via celestial navigation is demonstrated. From the list of navigational binary stars, fourteen such binary systems with at least 3.0 arcseconds apparent separation are explored. Maximum navigational error is estimated under the assumption that the bright star in the pair is observed at maximum separation, but the center-of-light is employed in the navigational solution. The relationships between navigational error and separation, orbital periods, and observers' latitude are discussed.

Numerical Simulations of Close and Contact Binary Systems Having Bipolytropic Equation of State

NASA Astrophysics Data System (ADS)

Kadam, Kundan; Clayton, Geoffrey C.; Motl, Patrick M.; Marcello, Dominic; Frank, Juhan

2017-01-01

I present the results of the numerical simulations of the mass transfer in close and contact binary systems with both stars having a bipolytropic (composite polytropic) equation of state. The initial binary systems are obtained by a modifying Hachisu’s self-consistent field technique. Both the stars have fully resolved cores with a molecular weight jump at the core-envelope interface. The initial properties of these simulations are chosen such that they satisfy the mass-radius relation, composition and period of a late W-type contact binary system. The simulations are carried out using two different Eulerian hydrocodes, Flow-ER with a fixed cylindrical grid, and Octo-tiger with an AMR capable cartesian grid. The detailed comparison of the simulations suggests an agreement between the results obtained from the two codes at different resolutions. The set of simulations can be treated as a benchmark, enabling us to reliably simulate mass transfer and merger scenarios of binary systems involving bipolytropic components.

Comparative Study of Novel Ratio Spectra and Isoabsorptive Point Based Spectrophotometric Methods: Application on a Binary Mixture of Ascorbic Acid and Rutin.

PubMed

Darwish, Hany W; Bakheit, Ahmed H; Naguib, Ibrahim A

2016-01-01

This paper presents novel methods for spectrophotometric determination of ascorbic acid (AA) in presence of rutin (RU) (coformulated drug) in their combined pharmaceutical formulation. The seven methods are ratio difference (RD), isoabsorptive_RD (Iso_RD), amplitude summation (A_Sum), isoabsorptive point, first derivative of the ratio spectra ((1)DD), mean centering (MCN), and ratio subtraction (RS). On the other hand, RU was determined directly by measuring the absorbance at 358 nm in addition to the two novel Iso_RD and A_Sum methods. The work introduced in this paper aims to compare these different methods, showing the advantages for each and making a comparison of analysis results. The calibration curve is linear over the concentration range of 4-50 μg/mL for AA and RU. The results show the high performance of proposed methods for the analysis of the binary mixture. The optimum assay conditions were established and the proposed methods were successfully applied for the assay of the two drugs in laboratory prepared mixtures and combined pharmaceutical tablets with excellent recoveries. No interference was observed from common pharmaceutical additives.

Comparative Study of Novel Ratio Spectra and Isoabsorptive Point Based Spectrophotometric Methods: Application on a Binary Mixture of Ascorbic Acid and Rutin

PubMed Central

Darwish, Hany W.; Bakheit, Ahmed H.; Naguib, Ibrahim A.

2016-01-01

This paper presents novel methods for spectrophotometric determination of ascorbic acid (AA) in presence of rutin (RU) (coformulated drug) in their combined pharmaceutical formulation. The seven methods are ratio difference (RD), isoabsorptive_RD (Iso_RD), amplitude summation (A_Sum), isoabsorptive point, first derivative of the ratio spectra (1DD), mean centering (MCN), and ratio subtraction (RS). On the other hand, RU was determined directly by measuring the absorbance at 358 nm in addition to the two novel Iso_RD and A_Sum methods. The work introduced in this paper aims to compare these different methods, showing the advantages for each and making a comparison of analysis results. The calibration curve is linear over the concentration range of 4–50 μg/mL for AA and RU. The results show the high performance of proposed methods for the analysis of the binary mixture. The optimum assay conditions were established and the proposed methods were successfully applied for the assay of the two drugs in laboratory prepared mixtures and combined pharmaceutical tablets with excellent recoveries. No interference was observed from common pharmaceutical additives. PMID:26885440

Mass flow in interacting binaries observed in the ultraviolet

NASA Technical Reports Server (NTRS)

Kondo, Yoji

1989-01-01

Recent satellite observations of close binary systems show that practically all binaries exhibit evidence of mass flow and that, where the observations are sufficiently detailed, a fraction of the matter flowing out of the mass-losing component is accreted by the companion and the remainder is lost from the binary system. The mass flow is not conservative. During the phase of dynamic mass flow, the companion star becomes immersed in optically-thick plasma and the physical properties of that star elude close scrutiny.

In what sense a neutron star-black hole binary is the holy grail for testing gravity?

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

Bagchi, Manjari; Torres, Diego F., E-mail: manjari.bagchi@icts.res.in, E-mail: dtorres@ieec.uab.es

2014-08-01

Pulsars in binary systems have been very successful to test the validity of general relativity in the strong field regime [1-4]. So far, such binaries include neutron star-white dwarf (NS-WD) and neutron star-neutron star (NS-NS) systems. It is commonly believed that a neutron star-black hole (NS-BH) binary will be much superior for this purpose. But in what sense is this true? Does it apply to all possible deviations?.

Evolutionary Pathways for Asteroid Satellites

NASA Astrophysics Data System (ADS)

Jacobson, Seth Andrew

2015-08-01

The YORP-induced rotational fission hypothesis is a proposed mechanism for the creation of small asteroid binaries, which make up approximately 1/6-th of the near-Earth asteroid and small Main Belt asteroid populations. The YORP effect is a radiative torque that rotationally accelerates asteroids on timescales of thousands to millions of years. As asteroids rotationally accelerate, centrifugal accelerations on material within the body can match gravitational accelerations holding that material in place. When this occurs, that material goes into orbit. Once in orbit that material coalesces into a companion that undergoes continued dynamical evolution.Observations with radar, photometric and direct imaging techniques reveal a diverse array of small asteroid satellites. These systems can be sorted into a number of morphologies according to size, multiplicity of members, dynamical orbit and spin states, and member shapes. For instance, singly synchronous binaries have short separation distances between the two members, rapidly rotating oblate primary members, and tidally locked prolate secondary members. Other confirmed binary morphologies include doubly synchronous, tight asynchronous and wide asynchronous binaries. Related to these binary morphologies are unbound paired asteroid systems and bi-lobate contact binaries.A critical test for the YORP-induced rotational fission hypothesis is whether the binary asteroids produced evolve to the observed binary and related systems. In this talk I will review how this evolution is believed to occur according to gravitational dynamics, mutual body tides and the binary YORP effect.

Binary statistics among population II stars

NASA Astrophysics Data System (ADS)

Zinnecker, H.; Köhler, R.; Jahreiß, H.

2004-08-01

Population II stars are old, metal-poor, Galactic halo stars with high proper motion. We have carried out a visual binary survey of 164 halo stars in the solar neighborhood (median distance 100 pc), using infrared speckle interferometry, adaptive optics, and wide field direct imaging. The sample is based on the lists of Population II stars of Carney et al. (1994) and Norris (1986), with reliable distances from HIPPARCOS measurements. At face value, we found 33 binaries, 6 triples, and 1 quadruple system. When we limit ourselves to K-band flux ratios larger than 0.1 (to avoid background contamination), the numbers drop to 9 binaries and 1 triple, corresponding to a binary frequency of 6 - 7 % above our angular resolution limit of about 0.1 arcsec. If we count all systems with K-band flux ratios greater than 0.01, we obtain 15 more binaries and 3 more triples, corresponding to a binary frequency for projected separations in excess of 10 AU of around 20 %. This is to be compared with the frequency of spectroscopic binaries (up to a period of 3000 days) of Population II stars of about 15 % (Latham et al. 2002). We also determined a semi-major axis distribution for our visual Population II binary and triple systems, which appears to be remarkably different from that of Population I stars. Second epoch-observations must help confirm the reality of our results.

Optimization of binary thermodynamic and phase diagram data

NASA Astrophysics Data System (ADS)

Bale, Christopher W.; Pelton, A. D.

1983-03-01

An optimization technique based upon least squares regression is presented to permit the simultaneous analysis of diverse experimental binary thermodynamic and phase diagram data. Coefficients of polynomial expansions for the enthalpy and excess entropy of binary solutions are obtained which can subsequently be used to calculate the thermodynamic properties or the phase diagram. In an interactive computer-assisted analysis employing this technique, one can critically analyze a large number of diverse data in a binary system rapidly, in a manner which is fully self-consistent thermodynamically. Examples of applications to the Bi-Zn, Cd-Pb, PbCl2-KCl, LiCl-FeCl2, and Au-Ni binary systems are given.

TPH2 gene polymorphisms in the regulatory region are associated with paranoid schizophrenia in Northern Han Chinese.

PubMed

Xu, X M; Ding, M; Pang, H; Wang, B J

2014-03-12

In the last years, serotonin (5-HT) has been related with the pathophysiology of several psychiatric disorders, including schizophrenia. Thus, genes related to the serotonergic (5-HTergic) system are good candidate genes for schizophrenia. The rate-limiting enzyme of 5-HT synthesis is tryptophan hydroxylase 2 (TPH2). Single nucleotide polymorphisms (SNPs) in the regulatory regions of TPH2 gene may affect gene expression and biosynthesis of 5-HT triggering to various neuropsychiatric disorders related to 5-HT dysfunction. The present study explored the association of SNPs within the TPH2 gene with paranoid schizophrenia in Han Chinese. A total of 164 patients with schizophrenia and 244 healthy controls were genotyped for six TPH2 SNPs (rs4570625, rs11178997, rs11178998, rs41317118, rs17110747, and rs41317114). Significant group differences were observed in the allele and genotype frequencies of rs4570625 and in the frequencies of GTA and TTA haplotypes corresponding to rs4570625-rs11178997-rs11178998. Our findings suggest that common genetic variations of TPH2 are likely to contribute to genetic susceptibility to paranoid schizophrenia in Han Chinese. Further studies in larger samples are needed to replicate this association.

Application of the Double-Tangent Construction of Coexisting Phases to Any Type of Phase Equilibrium for Binary Systems Modeled with the Gamma-Phi Approach

ERIC Educational Resources Information Center

Jaubert, Jean-Noël; Privat, Romain

2014-01-01

The double-tangent construction of coexisting phases is an elegant approach to visualize all the multiphase binary systems that satisfy the equality of chemical potentials and to select the stable state. In this paper, we show how to perform the double-tangent construction of coexisting phases for binary systems modeled with the gamma-phi…

Radial Velocity Studies of Close Binary Stars. XI.

NASA Astrophysics Data System (ADS)

Pribulla, Theodor; Rucinski, Slavek M.; Lu, Wenxian; Mochnacki, Stefan W.; Conidis, George; Blake, R. M.; DeBond, Heide; Thomson, J. R.; Pych, Wojtek; Ogłoza, Waldemar; Siwak, Michal

2006-08-01

Radial-velocity measurements and sine-curve fits to orbital radial velocity variations are presented for 10 close binary systems: DU Boo, ET Boo, TX Cnc, V1073 Cyg, HL Dra, AK Her, VW LMi, V566 Oph, TV UMi, and AG Vir. With this contribution, the David Dunlap Observatory program has reached the point of 100 published radial velocity orbits. The radial velocities have been determined using an improved fitting technique that uses rotational profiles to approximate individual peaks in broadening functions. Three systems, ET Boo, VW LMi, and TV UMi, are found to be quadruple, while AG Vir appears to be a spectroscopic triple. ET Boo, a member of a close visual binary with Pvis=113 yr, was previously known to be a multiple system, but we show that the second component is actually a close, noneclipsing binary. The new observations have enabled us to determine the spectroscopic orbits of the companion, noneclipsing pairs in ET Boo and VW LMi. A particularly interesting case is VW LMi, for which the period of the mutual revolution of the two spectroscopic binaries is only 355 days. While most of the studied eclipsing pairs are contact binaries, ET Boo is composed of two double-lined detached binaries, and HL Dra is a single-lined detached or semidetached system. Five systems of this group have been observed spectroscopically before: TX Cnc, V1073 Cyg, AK Her (as a single-lined binary), V566 Oph, and AG Vir, but our new data are of much higher quality than in the previous studies. Based on data obtained at the David Dunlap Observatory, University of Toronto, Canada.

Candidate Binary Microlensing Events from the MACHO Project

NASA Astrophysics Data System (ADS)

Becker, A. C.; Alcock, C.; Allsman, R. A.; Alves, D. R.; Axelrod, T. S.; Bennett, D. P.; Cook, K. H.; Drake, A. J.; Freeman, K. C.; Griest, K.; King, L. J.; Lehner, M. J.; Marshall, S. L.; Minniti, D.; Peterson, B. A.; Popowski, P.; Pratt, M. R.; Quinn, P. J.; Rodgers, A. W.; Stubbs, C. W.; Sutherland, W.; Tomaney, A.; Vandehei, T.; Welch, D. L.; Baines, D.; Brakel, A.; Crook, B.; Howard, J.; Leach, T.; McDowell, D.; McKeown, S.; Mitchell, J.; Moreland, J.; Pozza, E.; Purcell, P.; Ring, S.; Salmon, A.; Ward, K.; Wyper, G.; Heller, A.; Kaspi, S.; Kovo, O.; Maoz, D.; Retter, A.; Rhie, S. H.; Stetson, P.; Walker, A.; MACHO Collaboration

1998-12-01

We present the lightcurves of 22 gravitational microlensing events from the first six years of the MACHO Project gravitational microlensing survey which are likely examples of lensing by binary systems. These events were selected from a total sample of ~ 300 events which were either detected by the MACHO Alert System or discovered through retrospective analyses of the MACHO database. Many of these events appear to have undergone a caustic or cusp crossing, and 2 of the events are well fit with lensing by binary systems with large mass ratios, indicating secondary companions of approximately planetary mass. The event rate is roughly consistent with predictions based upon our knowledge of the properties of binary stars. The utility of binary lensing in helping to solve the Galactic dark matter problem is demonstrated with analyses of 3 binary microlensing events seen towards the Magellanic Clouds. Source star resolution during caustic crossings in 2 of these events allows us to estimate the location of the lensing systems, assuming each source is a single star and not a short period binary. * MACHO LMC-9 appears to be a binary lensing event with a caustic crossing partially resolved in 2 observations. The resulting lens proper motion appears too small for a single source and LMC disk lens. However, it is considerably less likely to be a single source star and Galactic halo lens. We estimate the a priori probability of a short period binary source with a detectable binary character to be ~ 10 %. If the source is also a binary, then we currently have no constraints on the lens location. * The most recent of these events, MACHO 98-SMC-1, was detected in real-time. Follow-up observations by the MACHO/GMAN, PLANET, MPS, EROS and OGLE microlensing collaborations lead to the robust conclusion that the lens likely resides in the SMC.

FOXP3 gene variations and susceptibility to autism: A case-control study.

PubMed

Safari, Mohammad Reza; Ghafouri-Fard, Soudeh; Noroozi, Rezvan; Sayad, Arezou; Omrani, Mir Davood; Komaki, Alireza; Eftekharian, Mohammad Mahdi; Taheri, Mohammad

2017-01-05

Autism Spectrum Disorders (ASD) are a group of heterogeneous neurodevelopmental disorders associated with immune system dysregulation. There are supporting evidences for the role of Forkhead Box P3 (FOXP3) gene as a lineage specification factor of regulatory T cells in the pathogenesis of ASD. The aim of this study was to explore possible relationship between genetic variants rs2232365 and rs3761548 of FOXP3 and ASD in 523 ASD patients versus 472 control individuals. Allele frequency analyses showed significant overpresentation of rs2232365-G allele in cases versus controls. In addition, rs2232365 GG genotype was associated with ASD in dominant inheritance model. Haplotype analysis revealed no significant association of any estimated block of rs2232365/rs3761548 with ASD. Our study indicated that rs2232365 is associated with ASD. Copyright © 2016 Elsevier B.V. All rights reserved.

Shaping planetary nebulae with jets in inclined triple stellar systems

NASA Astrophysics Data System (ADS)

Akashi, Muhammad; Soker, Noam

2017-08-01

We conduct three-dimensional hydrodynamical simulations of two opposite jets launched obliquely to the orbital plane around an asymptotic giant branch (AGB) star and within its dense wind, and demonstrate the formation of a 'messy' planetary nebula (PN), namely a PN lacking any type of symmetry (I.e. highly irregular). In building the initial conditions, we assume that a tight binary system orbits the AGB star and that the orbital plane of the tight binary system is inclined to the orbital plane of the binary system and the AGB star (the triple system plane). We further assume that the accreted mass on to the tight binary system forms an accretion disc around one of the stars and that the plane of the disc is tilted to the orbital plane of the triple system. The highly asymmetrical and filamentary structures that we obtain support the notion that messy PNe might be shaped by triple stellar systems.

Starspots on V711 Tauri /HR 1099/

NASA Astrophysics Data System (ADS)

Dorren, J. D.; Siah, M. J.; Guinan, E. F.; McCook, G. P.

1981-04-01

Hα (λ6563) intermediate- and narrowband light curves of the RS CVn-type binary system V711 Tau (HR 1099) were obtained in 1977-1978 at Biruni Observatory and in 1977-1978 and late 1979 at Villanova Observatory, where a λ7790 light curve was also obtained in 1977-1978. The light curves are quasisinusoidal, with a period approximately equal to the spectroscopic period. A significant change in the λ6585 light curve occurred between the two observing seasons, with an increase in amplitude from 0.075 to 0.125 mag, a change of shape, and an advance in the phases of maximum and minimum light by 0.3 phase. Flaring activity in Hα was observed, on time scales from minutes to days. We fitted our light curves and V-band light curves obtained at the same time using the starspot model of Torres and Ferraz Mello. We the observed light variations are due to the synchronous rotation of spots on the heavier member of the binary system, which has been shown to be the chromospherically active star. The orbital inclination was assumed to be 35°. Radiant fluxes were taken from spectrophotometric tables. Owing to the broad wavelength coverage in 1977-1978, it was possible to determine the spot temperature to be ˜1800 K cooler than the photosphere, and hence to fix the spot area. A simple model with two circular spots of 26° radius at the same latitude, +48°, adequately reproduces the 1977-1978 light curves. The 1979 observations can be reproduced in detail by a model with two slightly larger circular spots of 31°.5 radius at latitude +15°. The spots cover about 14% of the total stellar surface in 1979. The fits also provide an explanation of the presence of an observed phase dependence in the Hα emission in 1979 but not in 1977-1978. There is a strong suggestion that a spot cycle is in progress in V711 Tau.

RS-25D engine

NASA Image and Video Library

2012-01-17

Employees unload a RS25D rocket engine at NASA's John C. Stennis Space Center on Jan. 17. The engine - and 14 others - will be stored at the facility for future testing and use on NASA's new Space Launch System (SLS). The SLS is a new heavy-lift launch vehicle that will expand human presence beyond low-Earth orbit and enable new missions of exploration across the solar system. NASA's Marshall Space Flight Center in Huntsville, Ala., is leading the design and development of the Space Launch System for NASA, including the engine testing program. Delivery of the 15 RS-25 engines will continue throughout the next few months

Low complexity Reed-Solomon-based low-density parity-check design for software defined optical transmission system based on adaptive puncturing decoding algorithm

NASA Astrophysics Data System (ADS)

Pan, Xiaolong; Liu, Bo; Zheng, Jianglong; Tian, Qinghua

2016-08-01

We propose and demonstrate a low complexity Reed-Solomon-based low-density parity-check (RS-LDPC) code with adaptive puncturing decoding algorithm for elastic optical transmission system. Partial received codes and the relevant column in parity-check matrix can be punctured to reduce the calculation complexity by adaptive parity-check matrix during decoding process. The results show that the complexity of the proposed decoding algorithm is reduced by 30% compared with the regular RS-LDPC system. The optimized code rate of the RS-LDPC code can be obtained after five times iteration.

Photometric detection of a candidate low-mass giant binary system at the Milky Way Galactic Center

NASA Astrophysics Data System (ADS)

Krishna Gautam, Abhimat; Do, Tuan; Ghez, Andrea; Sakai, Shoko; Morris, Mark; Lu, Jessica; Witzel, Gunther; Jia, Siyao; Becklin, Eric Eric; Matthews, Keith

2018-01-01

We present the discovery of a new periodic variable star at the Milky Way Galactic Center (GC). This study uses laser guide-star adaptive optics data collected with the W. M. Keck 10 m telescope in the K‧-band (2.2 µm) over 35 nights spanning an 11 year time baseline, and 5 nights of additional H-band (1.6 µm) data. We implemented an iterative photometric calibration and local correction technique, resulting in a photometric uncertainty of Δm_K‧ ∼ 0.03 to a magnitude of m_K‧ ∼ 16.The periodically variable star has a 39.42 day period. We find that the star is not consistent with known periodically variable star classes in this period range with its observed color and luminosity, nor with an eclipsing binary system. The star's color and luminosity are however consistent with an ellipsoidal binary system at the GC, consisting of a K-giant and a dwarf component with an orbital period of 78.84 days. If a binary system, it represents the first detection of a low-mass giant binary system in the central half parsec of the GC. Such long-period binary systems can easily evaporate in the dense environment of the GC due to interactions with other stars. The existence and properties of a low-mass, long-period binary system can thus place valuable constraints on dynamical models of the GC environment and probe the density of the hypothesized dark cusp of stellar remnants at the GC.

IREB2, CHRNA5, CHRNA3, FAM13A & hedgehog interacting protein genes polymorphisms & risk of chronic obstructive pulmonary disease in Tatar population from Russia.

PubMed

Korytina, Gulnaz Faritovna; Akhmadishina, Leysan Zinurovna; Viktorova, Elena Vitalievna; Kochetova, Olga Vladimirovna; Viktorova, Tatyana Victorovna

2016-12-01

Chronic obstructive pulmonary disease (COPD) is a complex chronic inflammatory disease of the respiratory system affecting primarily distal respiratory pathways and lung parenchyma. This study was aimed at investigating the association of COPD with IREB2, CHRNA5, CHRNA3, FAM13A and hedgehog interacting protein (HHIP) genes in a Tatar population from Russia. Six single nucleotide polymorphisms (SNPs) (rs13180, rs16969968, rs1051730, rs6495309, rs7671167, rs13118928) were genotyped by the real-time polymerase chain reaction in this study (511 COPD patients and 508 controls). Logistic regression was used to detect the association of SNPs and haplotypes of linked loci in different models. Linear regression analyses were performed to estimate the relationship between SNPs and lung function parameters and pack-years. The rs13180 (IREB2), rs16969968 (CHRNA5) and rs1051730 (CHRNA3) were significantly associated with COPD in additive model [Padj =0.00001, odds ratio (OR)=0.64; Padj =0.0001, OR=1.41 and Padj =0.0001, OR=1.47]. The C-G haplotype by rs13180 and rs1051730 was a protective factor for COPD in our population (Padj =0.0005, OR=0.61). These results were confirmed only in smokers. The rs16969968 and rs1051730 were associated with decrease of forced expiratory volume in 1 sec % predicted (Padj =0.005 and Padj =0.0019). Our study showed the association of rs13180, rs16969968 and rs1051730 with COPD and lung function in Tatar population from Russia. Further studies need to be done in other ethnic populations.

"Special Case" Stellar Blast Teaching Astronomers New Lessons About Cosmic Explosions

NASA Astrophysics Data System (ADS)

2006-07-01

A powerful thermonuclear explosion on a dense white-dwarf star last February has given astronomers their best look yet at the early stages of such explosions, called novae, and also is giving them tantalizing new clues about the workings of bigger explosions, called supernovae, that are used to measure the Universe. RS Ophiuchi Expansion RS Ophiuchi Expansion CREDIT: Rupen, Mioduszewski & Sokoloski, NRAO/AUI/NSF (Click on image for full-sized image and detailed caption) Using the National Science Foundation's Very Long Baseline Array (VLBA) and other telescopes, "We have seen structure in the blast earlier than in any other stellar explosion," said Tim O'Brien of the University of Manchester's Jodrell Bank Observatory in the U.K. "We see evidence that the explosion may be ejecting material in jets, contrary to theoretical models that assumed a spherical shell of ejected material," O'Brien added. The explosion occurred in a star system called RS Ophiuchi, in the constellation Ophiuchus. RS Ophiuchi consists of a dense white dwarf star with a red giant companion whose prolific stellar wind dumps material onto the surface of the white dwarf. When enough of this material has accumulated, theorists say, a gigantic thermonuclear explosion, similar to a hydrogen bomb but much larger, occurs. Systems such as RS Ophiuchi may eventually produce a vastly more powerful explosion -- a supernova -- when the white dwarf accumulates enough mass to cause it to collapse and explode violently. Because such supernova explosions (called Type 1a supernovae by astronomers) all are triggered as the white dwarf reaches the same mass, they are thought to be identical in their intrinsic brightness. This makes them extremely valuable as "standard candles" for measuring distances in the Universe. "We think the white dwarf in RS Ophiuchi is about as massive as a white dwarf can get, and so is close to the point when it will become a supernova," said Jennifer Sokoloski, of the Harvard- Smithsonian Center for Astrophysics. "If astronomers use such supernovae to measure the Universe, it's important to fully understand how these systems evolve prior to the explosion," she added. RS Ophiuchi is a "recurrent" nova that experienced such blasts in 1898, 1933, 1958, 1967, and 1985 prior to this year's event. Sokoloski also pointed out that RS Ophiuchi is "a very special type of system," in which the nova explosions occur inside a gaseous nebula created by the stellar wind coming from the red giant companion to the white dwarf. "This means that we can track the outward-moving blast wave from the explosion by observing X-rays produced as the blast plows through this nebula," said Sokoloski, who led a team using the Rossi X-Ray Timing Explorer (RXTE) satellite to do so. "One natural way to produce what we observe is with an explosion that was not spherical," she added. Another surprise came when the radio waves coming from RS Ophiuchi indicated that a strong magnetic field is present in the material ejected by the explosion. "This is the first case we've seen that showed signs of such a magnetic field in a recurrent nova," said Michael Rupen who, with Amy Mioduszewski, both of the National Radio Astronomy Observatory, and Sokoloski, did another study of the system using the VLBA. Rupen pointed out the importance of observing the object with both X-ray and radio telescopes. "What we could infer from the X-ray data, we could image with the radio telescopes," he said. All the researchers agree that their studies show that the explosion is more complex than scientists previously thought such blasts to be. "It's a jet-like explosion, probably shaped by the geometry of the binary-star system at the center," said O'Brien. Rupen added that RS Ophiuchi showed the "earliest detection ever of such a jet. In fact, we could actually tell -- within a couple of days -- when the jet turned on." The new information is valuable for understanding not just nova explosions but other stellar blasts, the scientists believe. "The physics is analogous to the physics of supernova explosions, so what we're learning from this object can be applied to supernovae and possibly to stellar explosions in general," Sokoloski said. In addition, she said, "in the early days of this explosion, we saw changes in the blast wave that it would take hundreds of years to see in a supernova explosion." The teams led by O'Brien and Sokoloski reported their findings in the July 20 edition of the scientific journal Nature. Rupen and Mioduszewski are submitting their results to the Astrophysical Journal Letters. Working with O'Brien were Mike Bode of Liverpool John Moores University in the U.K., Richard Porcas of the Max Planck Institute for Radioastronomy in Germany, Tom Muxlow of Jodrell Bank Observatory, Stewart Eyres of the University of Central Lancashire in the U.K., Rob Beswick, Simon Garrington and Richard Davis, all of Jodrell Bank, and Nye Evans of Keele University in the U.K. Working with Sokoloski were Gerardo Luna of the Harvard Smithsonian Center for Astrophysics, Koji Mukai of NASA's Goddard Space Flight Center and Scott Kenyon of the Harvard-Smithsonian Center for Astrophysics. In addition to the VLBA, O'Brien's group used the NSF's Very Large Array (VLA), the Multi-Element Radio-Linked Interferometer Network (MERLIN) in the U.K., and the European VLBI Network (EVN). The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Spectral properties of binary asteroids

NASA Astrophysics Data System (ADS)

Pajuelo, Myriam; Birlan, Mirel; Carry, Benoît; DeMeo, Francesca E.; Binzel, Richard P.; Berthier, Jérôme

2018-07-01

We present the first attempt to characterize the distribution of taxonomic class among the population of binary asteroids (15 per cent of all small asteroids). For that, an analysis of 0.8-2.5 µm near-infrared spectra obtained with the SpeX instrument on the NASA/IRTF (Infrared Telescope Facility) is presented. Taxonomic class and meteorite analogue is determined for each target, increasing the sample of binary asteroids with known taxonomy by 21 per cent. Most binary systems are bound in the S, X, and C classes, followed by Q and V types. The rate of binary systems in each taxonomic class agrees within uncertainty with the background population of small near-Earth objects and inner main belt asteroids, but for the C types which are under-represented among binaries.

The architecture of the hierarchical triple star KOI 928 from eclipse timing variations seen in Kepler photometry

DOE PAGES

Steffen, J. H.; Quinn, S. N.; Borucki, W. J.; ...

2011-10-01

We present a hierarchical triple star system (KIC 9140402) where a low mass eclipsing binary orbits a more massive third star. The orbital period of the binary (4.98829 Days) is determined by the eclipse times seen in photometry from NASA's Kepler spacecraft. The periodically changing tidal field, due to the eccentric orbit of the binary about the tertiary, causes a change in the orbital period of the binary. The resulting eclipse timing variations provide insight into the dynamics and architecture of this system and allow the inference of the total mass of the binary (0.424±0.017M circle-dot) and the orbital parametersmore » of the binary about the central star.« less

Decadal Variability of Surface Incident Solar Radiation over China

NASA Astrophysics Data System (ADS)

Wang, Kaicun

2015-04-01

Observations have reported a widespread dimming of surface incident solar radiation (Rs) from the 1950s to the 1980s and a brightening afterwards. However, none of the state-of-the-art earth system models, including those from the Coupled Model Intercomparison Project phase 5 (CMIP5), could successfully reproduce the dimming/brightening rates over China. This study provides metadata and reference data to investigate the observed variability of Rs in China. From 1958 to 1990, diffuse solar radiation (Rsdif) and direct solar radiation (Rsdir) was measured separately in China, from which Rs was calculated a sum. However, pyranometers used to measure Rsdif had a strong sensitivity drift problem, which introduced a spurious decreasing trend to Rsdif and Rs measurements. The observed Rsdir did not suffer from such sensitivity drift problem. From 1990 to 1993, the old instruments were replaced and measuring stations were relocated in China, which introduced an abrupt increase in the observed Rs. After 1993, Rs was measured by solid black thermopile pyranometers. Comprehensive comparisons between observation-based and model-based Rs performed in this research have shown that sunshine duration (SunDu)-derived Rs is of high quality and provide accurate estimate of decadal variability of Rs over China. SunDu-derived Rs averaged over 105 stations in China decreased at -2.9 W m-2 per decade from 1961 to 1990 and remained stable afterward. This decadal variability has been confirmed by the observed Rsdir, independent studies on aerosols and diurnal temperature range, and can be reproduced by certain high-quality earth system models. However, neither satellite retrievals (the Global Energy and Water Exchanges Project Surface Radiation Budget (GEWEX SRB)) nor reanalyses (ERA-Interim and Modern-Era Retrospective analysis for Research and Applications (MERRA)) can accurately reproduce such decadal variability of Rs over China for their exclusion of annual variability of tropospheric aerosols.

The role of the antioxidant system during intense endurance exercise: lessons from migrating birds.

PubMed

Cooper-Mullin, Clara; McWilliams, Scott R

2016-12-01

During migration, birds substantially increase their metabolic rate and burn fats as fuel and yet somehow avoid succumbing to overwhelming oxidative damage. The physiological means by which vertebrates such as migrating birds can counteract an increased production of reactive species (RS) are rather limited: they can upregulate their endogenous antioxidant system and/or consume dietary antioxidants (prophylactically or therapeutically). Thus, birds can alter different components of their antioxidant system to respond to the demands of long-duration flights, but much remains to be discovered about the complexities of RS production and antioxidant protection throughout migration. Here, we use bird migration as an example to discuss how RS are produced during endurance exercise and how the complex antioxidant system can protect against cellular damage caused by RS. Understanding how a bird's antioxidant system responds during migration can lend insights into how antioxidants protect birds during other life-history stages when metabolic rate may be high, and how antioxidants protect other vertebrates from oxidative damage during endurance exercise. © 2016. Published by The Company of Biologists Ltd.

Orbital period changes of OB-type contact binaries and their implications for the triplicity, formation and evolution of this type of binary stars

NASA Astrophysics Data System (ADS)

Qian, S.-B.; Kreiner, J. M.; Liu, L.; He, J.-J.; Zhu, L.-Y.; Yuan, J.-Z.; Dai, Z.-B.

2007-08-01

Orbital period variations of NINE well-observed OB-type contact binary stars, LY Aur, BH Cen, V382 CYg, V729 Cyg, AW Lac, TU Mus, RZ Pyx, V701 Sco and CT Tau, are investigated in detail. Of the nine systems, V701 Sco and CT Tau are two contact binaries containing twin components with a mass ratio of unit, LY Aur and V729 Cyg have the longest period among contact binary stars (P=4.0 and 6.6 days, respectively), and BH Cen and V701 Sco are the members of two extremely young galactic cluster IC 2994 and NGC 6383. It is discovered that, apart from the two systems with twin components (V701 Sco and CT Tau), the orbital periods of the rest SEVEN binary stars show a long-term increase. This is different from the situations of the late-type (W UMa-type) contact binaries where both secular period increase and decrease are usually encountered, indicating that magnetic field may play an important role in causing the long-term period decrease of W UMa-type contact binary stars. The fact that no long-term continuous period variations were found for V701 Sco and CT Tau may suggest that contact binary with twin components can be in an equilibrium. Based on the rates of period changes (dP/dt) of the SEVEN sample binary stars, statistical relations between dP/dt and orbital period (P) and the mean density of the secondary component were found. Our results suggest that the period increases of the short-period systems (P<2 days) may be mainly caused by a mass transfer from the less massive component to the more massive one, while for the long-period ones (P>2 days), LY Aur and V729 Cyg, their period increases may be resulted from a combination of stellar wind and mass transfer from the secondary to the primary. Meanwhile, cyclic period changes are found for all of the nine binary systems. Those periodic variations can be plausibly explained as the results of light-travel time effects suggesting that they are triple systems. The astrophysical parameters of the tertiary components in the nine systems have been determined. The tertiary components in the seven binaries, BH Cen, V382 Cyg, AW Lac, TU Mus, RZ Pyx, V701 Sco and CT Tau, may be invisible, while those in LY Aur and V729 Cyg may be the fainter visual companions in the two systems. It is possible that the tertiary components in those binaries played an important role for the formations and evolutions of the contact configurations by bringing angular momentum out from the central systems. Thus they have initial short period and can evolve into a contact configuration in a short timescale.

Accreting Black Hole Binaries in Globular Clusters

NASA Astrophysics Data System (ADS)

Kremer, Kyle; Chatterjee, Sourav; Rodriguez, Carl L.; Rasio, Frederic A.

2018-01-01

We explore the formation of mass-transferring binary systems containing black holes (BHs) within globular clusters (GC). We show that it is possible to form mass-transferring BH binaries with main sequence, giant, and white dwarf companions with a variety of orbital parameters in GCs spanning a large range in present-day properties. All mass-transferring BH binaries found in our models at late times are dynamically created. The BHs in these systems experienced a median of ∼30 dynamical encounters within the cluster before and after acquiring the donor. Furthermore, we show that the presence of mass-transferring BH systems has little correlation with the total number of BHs within the cluster at any time. This is because the net rate of formation of BH–non-BH binaries in a cluster is largely independent of the total number of retained BHs. Our results suggest that the detection of a mass-transferring BH binary in a GC does not necessarily indicate that the host cluster contains a large BH population.

The iron complex in high mass X-ray binaries

NASA Astrophysics Data System (ADS)

Giménez-García, A.; Torrejón, J. M.; Martínez-Núñez, S.; Rodes-Rocas, J. J.; Bernabéu, G.

2013-05-01

An X-ray binary system consists of a compact object (a white dwarf, a neutron star or a black hole) accreting material from an optical companion star. The spectral type of the optical component strongly affects the mass transfer to the compact object. This is the reason why X-ray binary systems are usually divided in High Mass X-ray Binaries (companion O or B type, denoted HMXB) and Low Mass X-ray Binaries (companion type A or later). The HMXB are divided depending on the partner's luminosity class in two main groups: the Supergiant X-ray Binaries (SGXB) and Be X-ray Binaries (BeXB). We introduce the spectral characterization of a sample of 9 High Mass X-ray Binaries in the iron complex (˜ 6-7 keV). This spectral range is a fundamental tool in the study of the surrounding material of these systems. The sources have been divided into three main groups according to their current standard classification: SGXB, BeXB and γ Cassiopeae-like. The purpose of this work is to look for qualitative patterns in the iron complex, around 6-7 keV, in order to discern between current different classes that make up the group of HMXB. We find significant spectral patterns for each of the sets, reflecting differences in accretion physics thereof.

Gaia Assorted Mass Binaries Long Excluded from SLoWPoKES (GAMBLES): Identifying Ultra-wide Binary Pairs with Components of Diverse Mass

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

Oelkers, Ryan J.; Stassun, Keivan G.; Dhital, Saurav, E-mail: ryan.j.oelkers@vanderbilt.edu

The formation and evolution of binary star systems are some of the remaining key questions in modern astronomy. Wide binary pairs (separations >10{sup 3} au) are particularly intriguing because their low binding energies make it difficult for the stars to stay gravitationally bound over extended timescales, and thus to probe the dynamics of binary formation and dissolution. Our previous SLoWPoKES catalogs, I and II, provided the largest and most complete sample of wide-binary pairs of low masses. Here we present an extension of these catalogs to a broad range of stellar masses: the Gaia Assorted Mass Binaries Long Excluded frommore » SloWPoKES (GAMBLES), comprising 8660 statistically significant wide pairs that we make available in a living online database. Within this catalog we identify a subset of 543 long-lived (dissipation timescale >1.5 Gyr) candidate binary pairs, of assorted mass, with typical separations between 10{sup 3} and 10{sup 5.5} au (0.002–1.5 pc), using the published distances and proper motions from the Tycho -Gaia Astrometric Solution and Sloan Digital Sky Survey photometry. Each pair has at most a false positive probability of 0.05; the total expectation is 2.44 false binaries in our sample. Among these, we find 22 systems with 3 components, 1 system with 4 components, and 15 pairs consisting of at least 1 possible red giant. We find the largest long-lived binary separation to be nearly 3.2 pc; even so, >76% of GAMBLES long-lived binaries have large binding energies and dissipation lifetimes longer than 1.5 Gyr. Finally, we find that the distribution of binary separations is clearly bimodal, corroborating the findings from SloWPoKES and suggesting multiple pathways for the formation and dissipation of the widest binaries in the Galaxy.« less

Gaia Assorted Mass Binaries Long Excluded from SLoWPoKES (GAMBLES): Identifying Ultra-wide Binary Pairs with Components of Diverse Mass

NASA Astrophysics Data System (ADS)

Oelkers, Ryan J.; Stassun, Keivan G.; Dhital, Saurav

2017-06-01

The formation and evolution of binary star systems are some of the remaining key questions in modern astronomy. Wide binary pairs (separations >103 au) are particularly intriguing because their low binding energies make it difficult for the stars to stay gravitationally bound over extended timescales, and thus to probe the dynamics of binary formation and dissolution. Our previous SLoWPoKES catalogs, I and II, provided the largest and most complete sample of wide-binary pairs of low masses. Here we present an extension of these catalogs to a broad range of stellar masses: the Gaia Assorted Mass Binaries Long Excluded from SloWPoKES (GAMBLES), comprising 8660 statistically significant wide pairs that we make available in a living online database. Within this catalog we identify a subset of 543 long-lived (dissipation timescale >1.5 Gyr) candidate binary pairs, of assorted mass, with typical separations between 103 and 105.5 au (0.002-1.5 pc), using the published distances and proper motions from the Tycho-Gaia Astrometric Solution and Sloan Digital Sky Survey photometry. Each pair has at most a false positive probability of 0.05; the total expectation is 2.44 false binaries in our sample. Among these, we find 22 systems with 3 components, 1 system with 4 components, and 15 pairs consisting of at least 1 possible red giant. We find the largest long-lived binary separation to be nearly 3.2 pc even so, >76% of GAMBLES long-lived binaries have large binding energies and dissipation lifetimes longer than 1.5 Gyr. Finally, we find that the distribution of binary separations is clearly bimodal, corroborating the findings from SloWPoKES and suggesting multiple pathways for the formation and dissipation of the widest binaries in the Galaxy.

Association of a common interferon regulatory factor 5 (IRF5) variant with increased risk of systemic lupus erythematosus (SLE).

PubMed

Demirci, F Y K; Manzi, S; Ramsey-Goldman, R; Minster, R L; Kenney, M; Shaw, P S; Dunlop-Thomas, C M; Kao, A H; Rhew, E; Bontempo, F; Kammerer, C; Kamboh, M I

2007-05-01

Interferon regulatory factor 5 (IRF5) belongs to a family of transcription factors that control the transactivation of type I interferon system-related genes, as well as the expression of several other genes involved in immune response, cell signalling, cell cycle control and apoptosis. Two recent studies reported a significant association between the IRF5/rs2004640 T allele and systemic lupus erythematosus (SLE). The purpose of this study was to determine whether the reported rs2004640 T allele association could be replicated in our independent SLE case-control sample. We genotyped DNA samples from 370 white SLE-affected female subjects and 462 white healthy female controls using the TaqMan Assay-on-Demand for rs2004640, and performed a case-control genetic association analysis. Frequency of the rs2004640 T allele was significantly higher in cases than in controls (56.5% vs. 50%; P= 0.008). The odds ratio for T allele carriers was 1.68 (95% CI: 1.20 - 2.34; P= 0.003). Our results in an independent case-control sample confirm the robust association of the IRF5/rs2004640 T allele with SLE risk, and further support the relevance of the type I interferon system in the pathogenesis of SLE and autoimmunity.

Autoregulation and Virulence Control by the Toxin-Antitoxin System SavRS in Staphylococcus aureus

PubMed Central

Wen, Wen; Liu, Banghui; Xue, Lu; Zhu, Zhongliang; Niu, Liwen

2018-01-01

ABSTRACT Toxin-antitoxin (TA) systems play diverse physiological roles, such as plasmid maintenance, growth control, and persister cell formation, but their involvement in bacterial pathogenicity remains largely unknown. Here, we have identified a novel type II toxin-antitoxin system, SavRS, and revealed the molecular mechanisms of its autoregulation and virulence control in Staphylococcus aureus. Electrophoretic mobility shift assay and isothermal titration calorimetry data indicated that the antitoxin SavR acted as the primary repressor bound to its own promoter, while the toxin SavS formed a complex with SavR to enhance the ability to bind to the operator site. DNase I footprinting assay identified the SavRS-binding site containing a short and long palindrome in the promoter region. Further, mutation and DNase I footprinting assay demonstrated that the two palindromes were crucial for DNA binding and transcriptional repression. More interestingly, genetic deletion of the savRS system led to the increased hemolytic activity and pathogenicity in a mouse subcutaneous abscess model. We further identified two virulence genes, hla and efb, by real-time quantitative reverse transcription-PCR and demonstrated that SavR and SavRS could directly bind to their promoter regions to repress virulence gene expression. PMID:29440365

Effect of Iron Availability on Induction of Systemic Resistance to Fusarium Wilt of Chickpea by Pseudomonas spp.

PubMed

Saikia, Ratul; Srivastava, Alok K; Singh, Kiran; Arora, Dilip K; Lee, Min-Woong

2005-03-01

Selected isolates of Pseudomonas fluorescens (Pf4-92 and PfRsC5) and P. aeruginosa (PaRsG18 and PaRsG27) were examined for growth promotion and induced systemic resistance against Fusarium wilt of chickpea. Significant increase in plant height was observed in Pseudomonas treated plants. However, plant growth was inhibited when isolates of Pseudomonas were used in combination with Fusarium oxysporum f. sp. ciceri (FocRs1). It was also observed that the Pseudomonas spp. was colonized in root of chickpea and significantly suppressed the disease in greenhouse condition. Rock wool bioassay technique was used to study the effect of iron availability on the induction of systemic resistance to Fusarium wilt of chickpea mediated by the Pseudomonas spp. All the isolates of Pseudomonas spp. showed greater disease control in the induced systemic resistance (ISR) bioassay when iron availability in the nutrient solution was low. High performance liquid chromatography (HPLC) analysis indicated that all the bacterial isolates produced more salicylic acid (SA) at low iron (10µM EDDHA) than high iron availability (10µFe(3+) EDDHA). Except PaRsG27, all the three isolates produced more pseudobactin at low iron than high iron availability.

Effect of Iron Availability on Induction of Systemic Resistance to Fusarium Wilt of Chickpea by Pseudomonas spp.

PubMed Central

Saikia, Ratul; Srivastava, Alok K.; Singh, Kiran; Lee, Min-Woong

2005-01-01

Selected isolates of Pseudomonas fluorescens (Pf4-92 and PfRsC5) and P. aeruginosa (PaRsG18 and PaRsG27) were examined for growth promotion and induced systemic resistance against Fusarium wilt of chickpea. Significant increase in plant height was observed in Pseudomonas treated plants. However, plant growth was inhibited when isolates of Pseudomonas were used in combination with Fusarium oxysporum f. sp. ciceri (FocRs1). It was also observed that the Pseudomonas spp. was colonized in root of chickpea and significantly suppressed the disease in greenhouse condition. Rock wool bioassay technique was used to study the effect of iron availability on the induction of systemic resistance to Fusarium wilt of chickpea mediated by the Pseudomonas spp. All the isolates of Pseudomonas spp. showed greater disease control in the induced systemic resistance (ISR) bioassay when iron availability in the nutrient solution was low. High performance liquid chromatography (HPLC) analysis indicated that all the bacterial isolates produced more salicylic acid (SA) at low iron (10µM EDDHA) than high iron availability (10µFe3+ EDDHA). Except PaRsG27, all the three isolates produced more pseudobactin at low iron than high iron availability. PMID:24049472

Relationship between miR-146a rs2910164 (G>C) Polymorphism and Digestive System Cancer Susceptibility: A Meta-Analysis.

PubMed

Xiong, Xin; Yan, Junfeng; Li, Linghua; Li, Yun; Cao, Yi; Tu, Yi; Mei, Jinhong

2017-08-01

MicroRNAs (miRNAs) are identified negatively regulating gene expression and acting as oncogenes or tumor suppressors in tumorigenesis. The association between miR-146a rs2910164 (G>C) polymorphism and susceptibility to digestive system cancers was contradictory and inconsistent in previously published studies. Presently, we performed a comprehensive literature retrieve on PubMed, Web of Science, Embase, Wanfang and CNKI databases to identify all relevant studies published before July 30, 2016. Odds ratio (OR) and 95% confidential interval (95%CI) were used to calculate the relationship between miR-146a rs2910164 (G>C) polymorphism and digestive system cancers susceptibility. Finally, a total of 45 publications comprising 47 separate case-control studies were enrolled in the present updated meta-analysis including 20,281 cases and 26,099 controls. However, no significant association was uncovered for miR-146a rs2910164 polymorphism and digestive system cancers susceptibility in all the genetic models. Moreover, in the stratification analyses by cancer type, the source of control, ethnicity and Hardy-Weinberg Equilibrium (HWE) status, we also revealed a negative result. To conclude, our work suggests that miR-146a rs2910164 (G>C) polymorphism is not a susceptibility factor for digestive system cancers. © 2017 by the Association of Clinical Scientists, Inc.

COSMIC probes into compact binary formation and evolution

NASA Astrophysics Data System (ADS)

Breivik, Katelyn

2018-01-01

The population of compact binaries in the galaxy represents the final state of all binaries that have lived up to the present epoch. Compact binaries present a unique opportunity to probe binary evolution since many of the interactions binaries experience can be imprinted on the compact binary population. By combining binary evolution simulations with catalogs of observable compact binary systems, we can distill the dominant physical processes that govern binary star evolution, as well as predict the abundance and variety of their end products.The next decades herald a previously unseen opportunity to study compact binaries. Multi-messenger observations from telescopes across all wavelengths and gravitational-wave observatories spanning several decades of frequency will give an unprecedented view into the structure of these systems and the composition of their components. Observations will not always be coincident and in some cases may be separated by several years, providing an avenue for simulations to better constrain binary evolution models in preparation for future observations.I will present the results of three population synthesis studies of compact binary populations carried out with the Compact Object Synthesis and Monte Carlo Investigation Code (COSMIC). I will first show how binary-black-hole formation channels can be understood with LISA observations. I will then show how the population of double white dwarfs observed with LISA and Gaia could provide a detailed view of mass transfer and accretion. Finally, I will show that Gaia could discover thousands black holes in the Milky Way through astrometric observations, yielding view into black-hole astrophysics that is complementary to and independent from both X-ray and gravitational-wave astronomy.

Identification of binary and multiple systems in TGAS using the Virtual Observatory

NASA Astrophysics Data System (ADS)

Jiménez-Esteban, F.; Solano, E.

2018-04-01

Binary and multiple stars have long provided an effective method of testing stellar formation and evolution theories. In particular, wide binary systems with separations > 20,000 au are particularly challenging as their physical separations are beyond the typical size of a collapsing cloud core (5,000 - 10,000 au). We present here a preliminary work in which we make use of the TGAS catalogue and Virtual Observatory tools and services (Aladin, TOPCAT, STILTS, VOSA, VizieR) to identify binary and multiple star candidate systems. The catalogue will be available from the Spanish VO portal (http://svo.cab.inta-csic.es) in the coming months.

The massive multiple system HD 64315

NASA Astrophysics Data System (ADS)

Lorenzo, J.; Simón-Díaz, S.; Negueruela, I.; Vilardell, F.; Garcia, M.; Evans, C. J.; Montes, D.

2017-10-01

Context. The O6 Vn star HD 64315 is believed to belong to the star-forming region known as NGC 2467, but previous distance estimates do not support this association. Moreover, it has been identified as a spectroscopic binary, but existing data support contradictory values for its orbital period. Aims: We explore the multiple nature of this star with the aim of determining its distance, and understanding its connection to NGC 2467. Methods: A total of 52 high-resolution spectra have been gathered over a decade. We use their analysis, in combination with the photometric data from All Sky Automated Survey and Hipparcos catalogues, to conclude that HD 64315 is composed of at least two spectroscopic binaries, one of which is an eclipsing binary. We have developed our own program to fit four components to the combined line shapes. Once the four radial velocities were derived, we obtained a model to fit the radial-velocity curves using the Spectroscopic Binary Orbit Program (SBOP). We then implemented the radial velocities of the eclipsing binary and the light curves in the Wilson-Devinney code iteratively to derive stellar parameters for its components. We were also able to analyse the non-eclipsing binary, and to derive minimum masses for its components which dominate the system flux. Results: HD 64315 contains two binary systems, one of which is an eclipsing binary. The two binaries are separated by 0.09 arcsec (or 500 AU) if the most likely distance to the system, 5 kpc, is considered. The presence of fainter companions is not excluded by current observations. The non-eclipsing binary (HD 64315 AaAb) has a period of 2.70962901 ± 0.00000021 d. Its components are hotter than those of the eclipsing binary, and dominate the appearance of the system. The eclipsing binary (HD 64315 BaBb) has a shorter period of 1.0189569 ± 0.0000008 d. We derive masses of 14.6 ± 2.3 M⊙ for both components of the BaBb system. They are almost identical; both stars are overfilling their respective Roche lobes, and share a common envelope in an overcontact configuration. The non-eclipsing binary is a detached system composed of two stars with spectral types around O6 V with minimum masses of 10.8 M⊙ and 10.2 M⊙, and likely masses ≈ 30 M⊙. Conclusions: HD 64315 provides a cautionary tale about high-mass star isolation and multiplicity. Its total mass is likely above 90M⊙, but it seems to have formed without an accompanying cluster. It contains one the most massive overcontact binaries known, a likely merger progenitor in a very wide multiple system. Based on observations obtained at the European Southern Observatory under programmes 078.D-0665(A), 082-D.0136 and 093.A-9001(A). Based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

Characterization of the Ignition Over-Pressure/Sound Suppression Water in the Space Launch System Mobile Launcher Using Volume of Fluid Modeling

NASA Technical Reports Server (NTRS)

West, Jeff

2015-01-01

The Space Launch System (SLS) Vehicle consists of a Core Stage with four RS-25 engines and two Solid Rocket Boosters (SRBs). This vehicle is launched from the Launchpad using a Mobile Launcher (ML) which supports the SLS vehicle until its liftoff from the ML under its own power. The combination of the four RS-25 engines and two SRBs generate a significant Ignition Over-Pressure (IOP) and Acoustic Sound environment. One of the mitigations of these environments is the Ignition Over-Pressure/Sound Suppression (IOP/SS) subsystem installed on the ML. This system consists of six water nozzles located parallel to and 24 inches downstream of each SRB nozzle exit plane as well as 16 water nozzles located parallel to and 53 inches downstream of the RS-25 nozzle exit plane. During launch of the SLS vehicle, water is ejected through each water nozzle to reduce the intensity of the transient pressure environment imposed upon the SLS vehicle. While required for the mitigation of the transient pressure environment on the SLS vehicle, the IOP/SS subsystem interacts (possibly adversely) with other systems located on the Launch Pad. One of the other systems that the IOP/SS water is anticipated to interact with is the Hydrogen Burn-Off Igniter System (HBOI). The HBOI system's purpose is to ignite the unburned hydrogen/air mixture that develops in and around the nozzle of the RS-25 engines during engine start. Due to the close proximity of the water system to the HBOI system, the presence of the IOP/SS may degrade the effectiveness of the HBOI system. Another system that the IOP/SS water may interact with adversely is the RS-25 engine nozzles and the SRB nozzles. The adverse interaction anticipated is the wetting, to a significant degree, of the RS-25 nozzles resulting in substantial weight of ice forming and water present to a significant degree upstream of the SRB nozzle exit plane inside the nozzle itself, posing significant additional blockage of the effluent that exits the nozzle upon motor start leading to detrimental effects. The purpose of the CFD simulations were to i) characterize the location of the IOP/SS water after it is ejected from the IOP/SS nozzles, ii) characterize the interaction of the IOP/SS system with the HBOI system and iii) characterize the interaction of the IOP/SS water with the RS-25 nozzles and the SRB nozzles.

Genetic polymorphisms in the serotonergic system are associated with circadian manifestations of bruxism.

PubMed

Oporto, G H; Bornhardt, T; Iturriaga, V; Salazar, L A

2016-11-01

Bruxism (BRX) is a condition of great interest for researchers and clinicians in dental and medical areas. BRX has two circadian manifestations; it can occur during sleep (sleep bruxism, SB) or during wakefulness (awake bruxism, WB). However, it can be suffered together. Recent investigations suggest that central nervous system neurotransmitters and their genes could be involved in the genesis of BRX. Serotonin is responsible for the circadian rhythm, maintaining arousal, regulating stress response, muscle tone and breathing. Thus, serotonin could be associated with BRX pathogenesis. The aim of this work was to evaluate the frequency of genetic polymorphisms in the genes HTR1A (rs6295), HTR2A (rs1923884, rs4941573, rs6313, rs2770304), HTR2C (rs17260565) and SLC6A4 (rs63749047) in subjects undergoing BRX treatment. Patients included were classified according to their diagnosis in awake bruxism (61 patients), sleep bruxism (26 patients) and both (43 patients). The control group included 59 healthy patients with no signs of BRX. Data showed significant differences in allelic frequencies for the HTR2A rs2770304 polymorphism, where the C allele was associated with increased risk of SB (odds ratio = 2·13, 95% confidence interval: 1·08-4·21, P = 0·03). Our results suggest that polymorphisms in serotonergic pathways are involved in sleep bruxism. Further research is needed to clarify and increase the current understanding of BRX physiopathology. © 2016 John Wiley & Sons Ltd.

Influence of the IL6 gene in susceptibility to systemic sclerosis.

PubMed

Cénit, Maria Carmen; Simeón, Carmen P; Vonk, Madelon C; Callejas-Rubio, Jose L; Espinosa, Gerard; Carreira, Patricia; Blanco, Francisco J; Narvaez, Javier; Tolosa, Carlos; Román-Ivorra, José A; Gómez-García, Inmaculada; García-Hernández, Francisco J; Gallego, María; García-Portales, Rosa; Egurbide, María Victoria; Fonollosa, Vicente; García de la Peña, Paloma; López-Longo, Francisco J; González-Gay, Miguel A; Hesselstrand, Roger; Riemekasten, Gabriela; Witte, Torsten; Voskuyl, Alexandre E; Schuerwegh, Annemie J; Madhok, Rajan; Fonseca, Carmen; Denton, Christopher; Nordin, Annika; Palm, Øyvind; van Laar, Jacob M; Hunzelmann, Nicolas; Distler, Jörg H W; Kreuter, Alexander; Herrick, Ariane; Worthington, Jane; Koeleman, Bobby P; Radstake, Timothy R D J; Martín, Javier

2012-12-01

Systemic sclerosis (SSc) is a genetically complex autoimmune disease; the genetic component has not been fully defined. Interleukin 6 (IL-6) plays a crucial role in immunity and fibrosis, both key aspects of SSc. We investigated the influence of IL6 gene in the susceptibility and phenotype expression of SSc. We performed a large metaanalysis including a total of 2749 cases and 3189 controls from 6 white populations (Germany, The Netherlands, Norway, Spain, Sweden, and United Kingdom). Three IL6 single-nucleotide polymorphisms (SNP; rs2069827, rs1800795, and rs2069840) were selected by SNP tagging and genotyped using TaqMan(®) allele discrimination technology. Individual SNP metaanalysis showed no evidence of association of the 3 IL6 genetic variants with the global disease. Phenotype analyses revealed a significant association between the minor allele of rs2069840 and the limited cutaneous SSc clinical form (Bonferroni p = 0.036, OR 1.14, 95% CI 1.04-1.25). A trend of association between the minor allele of the rs1800795 and the diffuse cutaneous SSc clinical form was also evident (Bonferroni p = 0.072, OR 0.86, 95% CI 0.77-0.96). In the IL6 allelic combination analyses, the GGC allelic combination rs2069827-rs1800795-rs2069840 showed an association with overall SSc (Bonferroni p = 0.016, OR 1.13, 95% CI 1.04-1.23). Our results suggest that the IL6 gene may influence the development of SSc and its progression.

Binary Microlensing Events from the MACHO Project

NASA Astrophysics Data System (ADS)

Alcock, C.; Allsman, R. A.; Alves, D.; Axelrod, T. S.; Baines, D.; Becker, A. C.; Bennett, D. P.; Bourke, A.; Brakel, A.; Cook, K. H.; Crook, B.; Crouch, A.; Dan, J.; Drake, A. J.; Fragile, P. C.; Freeman, K. C.; Gal-Yam, A.; Geha, M.; Gray, J.; Griest, K.; Gurtierrez, A.; Heller, A.; Howard, J.; Johnson, B. R.; Kaspi, S.; Keane, M.; Kovo, O.; Leach, C.; Leach, T.; Leibowitz, E. M.; Lehner, M. J.; Lipkin, Y.; Maoz, D.; Marshall, S. L.; McDowell, D.; McKeown, S.; Mendelson, H.; Messenger, B.; Minniti, D.; Nelson, C.; Peterson, B. A.; Popowski, P.; Pozza, E.; Purcell, P.; Pratt, M. R.; Quinn, J.; Quinn, P. J.; Rhie, S. H.; Rodgers, A. W.; Salmon, A.; Shemmer, O.; Stetson, P.; Stubbs, C. W.; Sutherland, W.; Thomson, S.; Tomaney, A.; Vandehei, T.; Walker, A.; Ward, K.; Wyper, G.

2000-09-01

We present the light curves of 21 gravitational microlensing events from the first six years of the MACHO Project gravitational microlensing survey that are likely examples of lensing by binary systems. These events were manually selected from a total sample of ~350 candidate microlensing events that were either detected by the MACHO Alert System or discovered through retrospective analyses of the MACHO database. At least 14 of these 21 events exhibit strong (caustic) features, and four of the events are well fit with lensing by large mass ratio (brown dwarf or planetary) systems, although these fits are not necessarily unique. The total binary event rate is roughly consistent with predictions based upon our knowledge of the properties of binary stars, but a precise comparison cannot be made without a determination of our binary lens event detection efficiency. Toward the Galactic bulge, we find a ratio of caustic crossing to noncaustic crossing binary lensing events of 12:4, excluding one event for which we present two fits. This suggests significant incompleteness in our ability to detect and characterize noncaustic crossing binary lensing. The distribution of mass ratios, N(q), for these binary lenses appears relatively flat. We are also able to reliably measure source-face crossing times in four of the bulge caustic crossing events, and recover from them a distribution of lens proper motions, masses, and distances consistent with a population of Galactic bulge lenses at a distance of 7+/-1 kpc. This analysis yields two systems with companions of ~0.05 Msolar.

Measuring social skills of children and adolescents in a Chinese population: Preliminary evidence on the reliability and validity of the translated Chinese version of the Social Skills Improvement System-Rating Scales (SSIS-RS-C).

PubMed

Cheung, Phoebe P P; Siu, Andrew M H; Brown, Ted

2017-01-01

The Social Skills Improvement System-Rating Scales (SSIS-RS; Gresham & Elliott, 2008) are designed to assist in the screening and classification of students (aged 5-18 years) who are suspected of presenting with social skills deficits and to offer guidelines in the development of interventions to remediate those types of problems. The objective of this study is to examine the preliminary reliability and validity of the translated Chinese version of the SSIS-RS, referred to as the SSIS-RS-C. In this study, parent-reported social skills and problem behaviors among students with typical development (n=79) were compared with those of age- and gender-matched students with a known developmental disability (n=79) using the SSIS-RS-C. The results indicated that the SSIS-RS-C subscale scores in all the disability groups were significantly different except for those in the Assertion scale for one disability group. Furthermore, the normative sample of typically developing children and adolescents (aged 5-12 and 13-18 years, n=567) from Hong Kong was established to improve the psychometric properties of the SSIS-RS-C. There were moderate to strong relationships between the common subscales across all forms of the SSIS-RS-C. Acceptable to excellent levels of internal consistency across all common subscales was also obtained. The scores for the Hong Kong sample (n=567) derived from the use of the SSIS-RS-C were then compared to the normative sample scores from the American version of the SSIS-RS. It was found that there were statistically significant differences on five out of the seven SSIS-RS-C Social Skill subscales for children aged 5-12 years and on four out of the seven SSIS-RS-C Social Skills subscales for the adolescent group (aged 13-18 years). Also, there were statistically significant differences between the American and Hong Kong samples on all of the SSIS-RS-C Problem Behavior scale scores. It was concluded that the SSIS-RS-C is a promising instrument for clinicians to be able to differentiate social skills and problem behaviors among students presenting with and without developmental disabilities in Hong Kong contexts. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

A contact binary asteroid evolutionary cycle driven by BYORP & the classical Laplace plane

NASA Astrophysics Data System (ADS)

Rieger, Samantha; Scheeres, Daniel J.

2017-10-01

Several contact binaries have been observed to have high obliquities distributed around 90°. With this information, we explore the possibility of these high obliquities being a key characteristic that causes an evolutionary cycle of contact binary formation and separation.The contact binary cycle begins with a single asteroid that is spinning up due to the YORP effect. For the binary cycle we assume YORP will drive the obliquity to 90°. Eventually, the asteroid will reach a critical spin frequency that will cause the asteroid to fission into a binary. We assume that the mass-ratio, q, of the system is greater than 0.2. With a high q, the secondary will not escape/impact the primary but will evolve through tides into a stable circular double-synchronous orbit. The binary being synchronous will cause the forces from BYORP to have secular effects on the system. For this cycle, BYORP will need to expand the secondary away from the primary.As the system expands, we have found that the secondary will follow the classical Laplace plane. Therefore, the secondary’s orbit will increase in inclination with respect to the equator as the secondary’s orbit expands. The Laplace plane is a stable orbit to perturbations from J2 & Sun tides except for an instability region that exists for primaries with obliquities above 68.875° & a secondary orbital radius of 13.5-19.5 primary radii. Once BYORP expands the secondary into this instability region, the eccentricity of the secondary’s orbit will increase until the orbit intersects with the primary & causes an impact. This impact will create a contact binary with a new obliquity that will randomly range from 23°-150°. The cycle will begin again with YORP driving the contact binary to an obliquity of 90°.Our contribution will discuss the proposed contact binary cycle in more detail, including the mechanics of the system that drives the events given above. We will include investigations into how losing synchronous lock will disrupt the eccentricity growth in the Laplace plane instability region. We will also discuss the time scales of each event to help predict which part of the cycle we will most likely to be observing when discovering new contact binaries & binary systems.

Resistance switching behavior of atomic layer deposited SrTiO3 film through possible formation of Sr2Ti6O13 or Sr1Ti11O20 phases

PubMed Central

Lee, Woongkyu; Yoo, Sijung; Yoon, Kyung Jean; Yeu, In Won; Chang, Hye Jung; Choi, Jung-Hae; Hoffmann-Eifert, Susanne; Waser, Rainer; Hwang, Cheol Seong

2016-01-01

Identification of microstructural evolution of nanoscale conducting phase, such as conducting filament (CF), in many resistance switching (RS) devices is a crucial factor to unambiguously understand the electrical behaviours of the RS-based electronic devices. Among the diverse RS material systems, oxide-based redox system comprises the major category of these intriguing electronic devices, where the local, along both lateral and vertical directions of thin films, changes in oxygen chemistry has been suggested to be the main RS mechanism. However, there are systems which involve distinctive crystallographic phases as CF; the Magnéli phase in TiO2 is one of the very well-known examples. The current research reports the possible presence of distinctive local conducting phase in atomic layer deposited SrTiO3 RS thin film. The conducting phase was identified through extensive transmission electron microscopy studies, which indicated that oxygen-deficient Sr2Ti6O13 or Sr1Ti11O20 phase was presumably present mainly along the grain boundaries of SrTiO3 after the unipolar set switching in Pt/TiN/SrTiO3/Pt structure. A detailed electrical characterization revealed that the samples showed typical bipolar and complementary RS after the memory cell was unipolar reset. PMID:26830978

Methods for Kinetic and Thermodynamic Analysis of Aminoacyl-tRNA Synthetases

PubMed Central

Francklyn, Christopher S.; First, Eric A.; Perona, John J.; Hou, Ya-Ming

2008-01-01

The accuracy of protein synthesis relies on the ability of aminoacyl-tRNA synthetases (aaRSs) to discriminate among true and near cognate substrates. To date, analysis of aaRSs function, including identification of residues of aaRS participating in amino acid and tRNA discrimination, has largely relied on the steady state kinetic pyrophosphate exchange and aminoacylation assays. Pre-steady state kinetic studies investigating a more limited set of aaRS systems have also been undertaken to assess the energetic contributions of individual enzyme-substrate interactions, particularly in the adenylation half reaction. More recently, a renewed interest in the use of rapid kinetics approaches for aaRSs has led to their application to several new aaRS systems, resulting in the identification of mechanistic differences that distinguish the two structurally distinct aaRS classes. Here, we review the techniques for thermodynamic and kinetic analysis of aaRS function. Following a brief survey of methods for the preparation of materials and for steady state kinetic analysis, this review will describe pre-steady state kinetic methods employing rapid quench and stopped-flow fluorescence for analysis of the activation and aminoacyl transfer reactions. Application of these methods to any aaRS system allows the investigator to derive detailed kinetic mechanisms for the activation and aminoacyl transfer reactions, permitting issues of substrate specificity, stereochemical mechanism, and inhibitor interaction to be addressed in a rigorous and quantitative fashion. PMID:18241792

Recapitulation of Candidate Systemic Lupus Erythematosus-Associated Variants in Koreans

PubMed Central

Kwon, Ki-Sung; Cho, Hye-Young

2016-01-01

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that affects multiple organ systems. Although the etiology of SLE remains unclear, it is widely accepted that genetic factors could be involved in its pathogenesis. A number of genome-wide association studies (GWASs) have identified novel single-nucleotide polymorphisms (SNPs) associated with the risk of SLE in diverse populations. However, not all the SNP candidates identified from non-Asian populations have been validated in Koreans. In this study, we aimed to replicate the SNPs that were recently discovered in the GWAS; these SNPs have not been validated in Koreans or have only been replicated in Koreans with an insufficient sample size to conclude any association. For this, we selected five SNPs (rs1801274 in FCGR2A and rs2286672 in PLD2, rs887369 in CXorf21, rs9782955 in LYST, and rs3794060 in NADSYN1). Through the replication study with 656 cases and 622 controls, rs1801274 in FCGR2A was found to be significantly associated with SLE in Koreans (odds ratio, 1.26, 95% confidence interval, 1.06 to 1.50; p = 0.01 in allelic model). This association was also significant in two other models (dominant and recessive). The other four SNPs did not show a significant association. Our data support that FCGR polymorphisms play important roles in the susceptibility to SLE in diverse populations, including Koreans. PMID:27729837

Recapitulation of Candidate Systemic Lupus Erythematosus-Associated Variants in Koreans.

PubMed

Kwon, Ki-Sung; Cho, Hye-Young; Chung, Yeun-Jun

2016-09-01

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that affects multiple organ systems. Although the etiology of SLE remains unclear, it is widely accepted that genetic factors could be involved in its pathogenesis. A number of genome-wide association studies (GWASs) have identified novel single-nucleotide polymorphisms (SNPs) associated with the risk of SLE in diverse populations. However, not all the SNP candidates identified from non-Asian populations have been validated in Koreans. In this study, we aimed to replicate the SNPs that were recently discovered in the GWAS; these SNPs have not been validated in Koreans or have only been replicated in Koreans with an insufficient sample size to conclude any association. For this, we selected five SNPs (rs1801274 in FCGR2A and rs2286672 in PLD2 , rs887369 in CXorf21 , rs9782955 in LYST , and rs3794060 in NADSYN1 ). Through the replication study with 656 cases and 622 controls, rs1801274 in FCGR2A was found to be significantly associated with SLE in Koreans (odds ratio, 1.26, 95% confidence interval, 1.06 to 1.50; p = 0.01 in allelic model). This association was also significant in two other models (dominant and recessive). The other four SNPs did not show a significant association. Our data support that FCGR polymorphisms play important roles in the susceptibility to SLE in diverse populations, including Koreans.

High-resolution spectroscopy of extremely metal-poor stars from SDSS/Segue. II. Binary fraction

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

Aoki, Wako; Suda, Takuma; Beers, Timothy C.

2015-02-01

The fraction of binary systems in various stellar populations of the Galaxy and the distribution of their orbital parameters are important but not well-determined factors in studies of star formation, stellar evolution, and Galactic chemical evolution. While observational studies have been carried out for a large sample of nearby stars, including some metal-poor Population II stars, almost no constraints on the binary nature for extremely metal-poor (EMP; [Fe/H] <−3.0) stars have yet been obtained. Here we investigate the fraction of double-lined spectroscopic binaries and carbon-enhanced metal-poor (CEMP) stars, many of which could have formed as pairs of low-mass and intermediate-massmore » stars, to estimate the lower limit of the fraction of binary systems having short periods. The estimate is based on a sample of very metal-poor stars selected from the Sloan Digital Sky Survey and observed at high spectral resolution in a previous study by Aoki et al. That survey reported 3 double-lined spectroscopic binaries and 11 CEMP stars, which we consider along with a sample of EMP stars from the literature compiled in the SAGA database. We have conducted measurements of the velocity components for stacked absorption features of different spectral lines for each double-lined spectroscopic binary. Our estimate indicates that the fraction of binary stars having orbital periods shorter than 1000 days is at least 10%, and possibly as high as 20% if the majority of CEMP stars are formed in such short-period binaries. This result suggests that the period distribution of EMP binary systems is biased toward short periods, unless the binary fraction of low-mass EMP stars is significantly higher than that of other nearby stars.« less

Inflammatory and Immune Response Genes Polymorphisms are Associated with Susceptibility to Chronic Obstructive Pulmonary Disease in Tatars Population from Russia.

PubMed

Korytina, Gulnaz Faritovna; Akhmadishina, L Z; Kochetova, O V; Aznabaeva, Y G; Zagidullin, Sh Z; Victorova, T V

2016-08-01

Chronic obstructive pulmonary disease (COPD) is a complex chronic inflammatory disease of the respiratory system affecting primarily distal respiratory pathways and lung parenchyma. This work was designed as a case-control study aimed at investigating the association of COPD with polymorphisms in inflammatory and immune response genes (JAK1, JAK3, STAT1, STAT3, NFKB1, IL17A, ADIPOQ, ADIPOR1, etc.) in Tatar population from Russia. Ten SNPs (rs310216, rs3212780, rs12693591, rs2293152, rs28362491, rs4711998, rs1974226, rs1501299, rs266729, and rs12733285) were genotyped by the real-time polymerase chain reaction (TaqMan assays) in a case-control study (425 COPD patients and 457 in the control group, from Ufa, Russia). Logistic regression was used to detect the association of SNPs in different models. Linear regression analyses were performed to estimate the relationship between SNPs and lung function parameters and pack-years. In Tatar population, significant associations of JAK1 (rs310216) (P = 0.0002, OR 1.70 in additive model), JAK3 (rs3212780) (P = 0.001, OR 1.61 in dominant model), and IL17A (rs1974226) (P = 0.0037, OR 2.31 in recessive model) with COPD were revealed. The disease risk was higher in carriers of insertion allele of NFKB1 (rs28362491) (P = 0.045, OR 1.22). We found a significant gene-by-environment interaction of smoking status and IL17A (rs1974226) (P interact = 0.016), JAK3 (rs3212780) (P interact = 0.031), ADIPOQ (rs266729) (P interact = 0.013), and ADIPOR1 (rs12733285) (P interact = 0.018). The relationship between the rs4711998, rs1974226, rs310216, rs3212780, rs28362491, and smoking pack-years was found (P = 0.045, P = 0.004, P = 0.0005, P = 0.021, and P = 0.042). A significant genotype-dependent variation of forced vital capacity was observed for NFKB1 (rs28362491) (P = 0.017), ADIPOR1 (rs12733285) (P = 0.043), and STAT1 (rs12693591) (P = 0.048). The genotypes of STAT1 (rs12693591) (P = 0.013) and JAK1 (rs310216) (P = 0.048) were associated with forced expiratory volume in 1 s.

Refractory Anemia with Ring Sideroblasts (RARS) and RARS with Thrombocytosis (RARS-T) – “2017 Update on Diagnosis, Risk-stratification, and Management”

PubMed Central

Patnaik, Mrinal M.; Tefferi, Ayalew

2017-01-01

Disease Overview Ring sideroblasts (RS) are erythroid precursors with abnormal perinuclear mitochondrial iron accumulation. Two myeloid neoplasms defined by the presence of RS, include refractory anemia with ring sideroblasts (RARS), now classified under myelodysplastic syndromes with RS (MDS-RS) and RARS with thrombocytosis (RARS-T); now called myelodysplastic/myeloproliferative neoplasm with RS and thrombocytosis (MDS/MPN-RS-T). Diagnosis MDS-RS is a lower risk MDS, with single or multilineage dysplasia (SLD/MLD), <5% bone marrow (BM) blasts and ≥15% BM RS (≥5% in the presence of SF3B1 mutations). MDS/MPN-RS-T, now a formal entity in the MDS/MPN overlap syndromes, has diagnostic features of MDS-RS-SLD, along with a platelet count ≥ 450 × 10(9)/L and large atypical megakaryocytes (similar to BCR-ABL1 negative MPN). Mutations and Karyotype Mutations in SF3B1 are seen in ≥80% of patients with MDS-RS-SLD and MDS/MPN-RS-T, and strongly correlate with the presence of BM RS; MDS/MPN-RS-T patients also demonstrate JAK2V617F, ASXL1, DNMT3A, SETBP1, and TET2 mutations; with ASXL1/SETBP1 mutations adversely impacting survival. Cytogenetic abnormalities are uncommon in both diseases. Risk stratification Most patients with MDS-RS-SLD are stratified into lower risk groups by the revised-International Prognostic Scoring System (R-IPSS). Disease outcome in MDS/MPN-RS-T is better than that of MDS-RS-SLD, but worse than that of essential thrombocythemia. Both diseases have a low risk of leukemic transformation. Treatment Anemia and iron overload are complications seen in both and are managed similar to lower risk MDS and MPN. Aspirin therapy is reasonable in MDS/MPN-RS-T, especially in the presence of JAK2V617F, but the value of platelet-lowering drugs is uncertain. PMID:28188970

Common gene variants interactions related to uric acid transport are associated with knee osteoarthritis susceptibility.

PubMed

Fernández-Torres, Javier; Martínez-Nava, Gabriela Angélica; Oliviero, Francesca; López-Reyes, Alberto Gabriel; Martínez-Flores, Karina; Garrido-Rodríguez, Daniela; Francisco-Balderas, Adriana; Zamudio-Cuevas, Yessica

2018-06-01

Background The presence of genetic variants in the uric acid (UA) transporters can be associated with hyperuricemia, and therefore with an increased risk of monosodium urate (MSU) crystal precipitation. The inflammatory process triggered by these crystals lead to cartilage damage which, in turn, could promote knee osteoarthritis (KOA). Objective To determine whether genetic polymorphisms of the UA transporters and its interactions are associated with KOA. Materials and Methods Two hundred forty-three unrelated Mexican-mestizo individuals were recruited for this case control-study. Ninety-three of them were KOA patients but without gout, and one hundred and fifty healthy individuals with no symptoms or signs of KOA were recruited as controls. Forty-one single nucleotide polymorphisms (SNPs) involved in the UA transporters were genotyped with OpenArray technology in a QuantStudio 12K flex-System both cases and controls. Results After adjusting by age, gender, BMI and ancestry, significant associations were found for 8 SNPs: rs1260326 (GCKR), rs780093 (GCKR), rs17050272 (INHBB), rs1471633 (PDZK1), rs12129861 (PDZK1), rs7193778 (IGF1R), rs17786744 (STC1) and rs1106766 (R3HDM2). With respect to gene-gene interactions, the pairwise interactions of rs112129861 (PDZK1) and rs7193778 (IGF1R); rs17050272 (INHBB) and rs1106766 (R3HDM2); rs1106766 (R3HDM2) and rs780093 (GCKR); rs1260326 (GCKR) and rs17786744 (STC1); and rs17786744 (STC1) and rs1106766 (R3HDM2), make it possible to visualize the synergistic or antagonistic effect of their genotypes or alleles on KOA development. Conclusions Our preliminary results show that the common gene variants related with the UA transport are associated with KOA in the Mexican population. Further studies must be done to corroborate it.

Liquid-liquid equilibria of binary mixtures of a lipidic ionic liquid with hydrocarbons.

PubMed

Green, Blane D; Badini, Alexander J; O'Brien, Richard A; Davis, James H; West, Kevin N

2016-01-28

Although structurally diverse, many ionic liquids (ILs) are polar in nature due to the strong coulombic forces inherent in ionic compounds. However, the overall polarity of the IL can be tuned by incorporating significant nonpolar content into one or more of the constituent ions. In this work, the binary liquid-liquid equilibria of one such IL, 1-methyl-3-(Z-octadec-9-enyl)imidazolium bistriflimide, with several hydrocarbons (n-hexane, n-octane, n-decane, cyclohexane, methylcyclohexane, 1-octene) is measured over the temperature range 0-70 °C at ambient pressure using a combination of cloud point and gravimetric techniques. The phase behavior of the systems are similar in that they exhibit two phases: one that is 60-90 mole% hydrocarbon and a second phase that is nearly pure hydrocarbon. Each phase exhibits a weak dependence of composition on temperature (steep curve) above ∼10 °C, likely due to swelling and restructuring of the nonpolar nano-domains of the IL being limited by energetically unfavorable restructuring in the polar nano-domains. The solubility of the n-alkanes decreases with increasing size (molar volume), a trend that continues for the cyclic alkanes, for which upper critical solution temperatures are observed below 70 °C. 1-Octene is found to be more soluble than n-octane, attributable to a combination of its lower molar volume and slightly higher polarity. The COSMO-RS model is used to predict the T-x'-x'' diagrams and gives good qualitative agreement of the observed trends. This work presents the highest known solubility of n-alkanes in an IL to date and tuning the structure of the ionic liquid to maximize the size/shape trends observed may provide the basis for enhanced separations of nonpolar species.

Near-Ultraviolet Observations of CS 29497-030: New Constraints on Neutron-Capture Nucleosynthesis Processes

NASA Astrophysics Data System (ADS)

Ivans, Inese I.; Sneden, Christopher; Gallino, Roberto; Cowan, John J.; Preston, George W.

2005-07-01

Employing spectra obtained with the new Keck I HIRES near-UV-sensitive detector, we have performed a comprehensive chemical composition analysis of the binary blue metal-poor star CS 29497-030. Abundances for 29 elements and upper limits for an additional seven have been derived, concentrating on elements largely produced by means of neutron-capture nucleosynthesis. Included in our analysis are the two elements that define the termination point of the slow neutron-capture process, lead and bismuth. We determine an extremely high value of [Pb/Fe]=+3.65+/-0.07 (σ=0.13) from three features, supporting the single-feature result obtained in previous studies. We detect Bi for the first time in a metal-poor star. Our derived Bi/Pb ratio is in accord with those predicted from the most recent FRANEC calculations of the slow neutron-capture process in low-mass asymptotic giant branch (AGB) stars. We find that the neutron-capture elemental abundances of CS 29497-030 are best explained by an AGB model that also includes very significant amounts of pre-enrichment of rapid neutron-capture process material in the protostellar cloud out of which the CS 29497-030 binary system formed. Mass transfer is consistent with the observed [Nb/Zr]~0. Thus, CS 29497-030 is both an r+s and ``extrinsic AGB'' star. Furthermore, we find that the mass of the AGB model can be further constrained by the abundance of the light odd-element Na. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

78 FR 70398 - Proposed Agency Information Collection Activities; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-25

... System Evaluation-Related Interview Data Collection. OMB Control Number: 2130-0574. Type of Request... approaches to improving safety, FRA has instituted the Confidential Close Call Reporting System (C\\3\\RS). The... reporting component, and a problem analysis/solution component. C\\3\\RS is expected to affect safety in two...

Growth phase-dependent activation of the DccRS regulon of Campylobacter jejuni

USDA-ARS?s Scientific Manuscript database

Two-component systems are widespread prokaryotic signal transduction devices which allow the regulation of cellular functions in response to changing environmental conditions. The two-component system DccRS (Cj1223-Cj1222) of Campylobacter jejuni is important for the colonization of chickens. Here w...

Synchronization, TIGoRS, and Information Flow in Complex Systems: Dispositional Cellular Automata.

PubMed

Sulis, William H

2016-04-01

Synchronization has a long history in physics where it refers to the phase matching of two identical oscillators. This notion has been extensively studied in physics as well as in biology, where it has been applied to such widely varying phenomena as the flashing of fireflies and firing of neurons in the brain. Human behavior, however, may be recurrent but it is not oscillatory even though many physiological systems do exhibit oscillatory tendencies. Moreover, much of human behaviour is collaborative and cooperative, where the individual behaviours may be distinct yet contemporaneous (if not simultaneous) and taken collectively express some functionality. In the context of behaviour, the important aspect is the repeated co-occurrence in time of behaviours that facilitate the propagation of information or of functionality, regardless of whether or not these behaviours are similar or identical. An example of this weaker notion of synchronization is transient induced global response synchronization (TIGoRS). Previous work has shown that TIGoRS is a ubiquitous phenomenon among complex systems, enabling them to stably parse environmental transients into salient units to which they stably respond. This leads to the notion of Sulis machines, which emergently generate a primitive linguistic structure through their dynamics. This article reviews the notion of TIGoRS and its expression in several complex systems models including tempered neural networks, driven cellular automata and cocktail party automata. The emergent linguistics of Sulis machines are discussed. A new class of complex systems model, the dispositional cellular automaton is introduced. A new metric for TIGoRS, the excess synchronization, is introduced and applied to the study of TIGoRS in dispositional cellular automata. It is shown that these automata exhibit a nonlinear synchronization response to certain perturbing transients.

Embedded binaries and their dense cores

NASA Astrophysics Data System (ADS)

Sadavoy, Sarah I.; Stahler, Steven W.

2017-08-01

We explore the relationship between young, embedded binaries and their parent cores, using observations within the Perseus Molecular Cloud. We combine recently published Very Large Array observations of young stars with core properties obtained from Submillimetre Common-User Bolometer Array 2 observations at 850 μm. Most embedded binary systems are found towards the centres of their parent cores, although several systems have components closer to the core edge. Wide binaries, defined as those systems with physical separations greater than 500 au, show a tendency to be aligned with the long axes of their parent cores, whereas tight binaries show no preferred orientation. We test a number of simple, evolutionary models to account for the observed populations of Class 0 and I sources, both single and binary. In the model that best explains the observations, all stars form initially as wide binaries. These binaries either break up into separate stars or else shrink into tighter orbits. Under the assumption that both stars remain embedded following binary break-up, we find a total star formation rate of 168 Myr-1. Alternatively, one star may be ejected from the dense core due to binary break-up. This latter assumption results in a star formation rate of 247 Myr-1. Both production rates are in satisfactory agreement with current estimates from other studies of Perseus. Future observations should be able to distinguish between these two possibilities. If our model continues to provide a good fit to other star-forming regions, then the mass fraction of dense cores that becomes stars is double what is currently believed.

Multiphase, multicomponent phase behavior prediction

NASA Astrophysics Data System (ADS)

Dadmohammadi, Younas

Accurate prediction of phase behavior of fluid mixtures in the chemical industry is essential for designing and operating a multitude of processes. Reliable generalized predictions of phase equilibrium properties, such as pressure, temperature, and phase compositions offer an attractive alternative to costly and time consuming experimental measurements. The main purpose of this work was to assess the efficacy of recently generalized activity coefficient models based on binary experimental data to (a) predict binary and ternary vapor-liquid equilibrium systems, and (b) characterize liquid-liquid equilibrium systems. These studies were completed using a diverse binary VLE database consisting of 916 binary and 86 ternary systems involving 140 compounds belonging to 31 chemical classes. Specifically the following tasks were undertaken: First, a comprehensive assessment of the two common approaches (gamma-phi (gamma-ϕ) and phi-phi (ϕ-ϕ)) used for determining the phase behavior of vapor-liquid equilibrium systems is presented. Both the representation and predictive capabilities of these two approaches were examined, as delineated form internal and external consistency tests of 916 binary systems. For the purpose, the universal quasi-chemical (UNIQUAC) model and the Peng-Robinson (PR) equation of state (EOS) were used in this assessment. Second, the efficacy of recently developed generalized UNIQUAC and the nonrandom two-liquid (NRTL) for predicting multicomponent VLE systems were investigated. Third, the abilities of recently modified NRTL model (mNRTL2 and mNRTL1) to characterize liquid-liquid equilibria (LLE) phase conditions and attributes, including phase stability, miscibility, and consolute point coordinates, were assessed. The results of this work indicate that the ϕ-ϕ approach represents the binary VLE systems considered within three times the error of the gamma-ϕ approach. A similar trend was observed for the for the generalized model predictions using quantitative structure-property parameter generalizations (QSPR). For ternary systems, where all three constituent binary systems were available, the NRTL-QSPR, UNIQUAC-QSPR, and UNIFAC-6 models produce comparable accuracy. For systems where at least one constituent binary is missing, the UNIFAC-6 model produces larger errors than the QSPR generalized models. In general, the LLE characterization results indicate the accuracy of the modified models in reproducing the findings of the original NRTL model.

A review of research on ecosystem of arid area using RS-GIS in China

NASA Astrophysics Data System (ADS)

Han, Hongling

2007-06-01

Arid area is classical mountain-oasis-desert ecosystem in North-west China. As the ecosystem has its nature geography character obviously, it has superior to research with remote-sensing and geography information system. The study on arid ecosystem in RS-GIS' way is focused on that the landscape spatial pattern of complex MODS ecosystem, the dynamic development of Land use/land cover, the security of ecological environment of eco-tone and so on. At the same time, the research on the single system is more and more, which has provided more ways and deeper fields of arid area using RS-GIS. Through the use of RS-GIS, desertification, oasis' development, urbanization etc. can be known, which would provide precaution for human-being and suitable ways to adjust the problems.

HLA variants rs9271366 and rs9275328 are associated with systemic lupus erythematosus susceptibility in Malays and Chinese.

PubMed

Chai, H C; Phipps, M E; Othman, I; Tan, L P; Chua, K H

2013-02-01

Human leukocyte antigen (HLA) antigens and genes have long been reported associated with systemic lupus erythematosus (SLE) susceptibility in many populations. With the advance in technologies such as genome-wide association studies, many newly discovered SLE-associated single-nucleotide polymorphisms (SNPs) have been reported in recent years. These include HLA-DRB1/HLA-DQA1 rs9271366 and HLA-DQB1/HLA-DQA2 rs9275328. Our aim was to investigate these SNPs in a Malaysian SLE cohort. SNPs rs9271366 and rs9275328 were screened across 790 Malaysian citizens from three ethnic groups (360 patients and 430 healthy volunteers) by Taqman SNP genotyping assays. Allele and genotyping frequencies, Hardy-Weinberg equilibrium, Fisher's exact test and odds ratio were calculated for each SNP and ethnic group. Linkage disequilibrium and interaction between the two SNPs were also evaluated. The minor allele G and its homozygous genotype GG of HLA-DRB1/HLA-DQA1 rs9271366 significantly increased the SLE susceptibility in Malaysian patients, including those of Malay and Chinese ethnicity (odds ratio (OR) > 1, p < 0.05). As for HLA-DQB1/HLA-DQA2 rs9275328, the minor allele T and the heterozygous genotype CT conferred protective effect to SLE in Malaysians, as well as in Malays and Chinese, by having OR < 1 and p value <0.05. Both SNPs did not show associations to SLE in Indians. D' and r (2) values for the two SNPs in LD analysis were 0.941 and 0.065, respectively, with haplotype GC and AT being significantly associated with SLE (p < 5.0 × 10(-4)) after 10,000 permutations were performed. The MDR test clustered the genotype combinations of GG and CC, and AG and CC of rs9271366 and rs9275328, accordingly, as high-risk group, and the two SNPs interacted redundantly by removing 1.96% of the entropy. Our findings suggest that in addition to some classical HLA variants, rs9271366 and rs9275328 are additional polymorphisms worth considering in the Malaysian and possibly in a larger Asian SLE scenario.

How do binary separations depend on cloud initial conditions?

NASA Astrophysics Data System (ADS)

Sterzik, M. F.; Durisen, R. H.; Zinnecker, H.

2003-11-01

We explore the consequences of a star formation scenario in which the isothermal collapse of a rotating, star-forming core is followed by prompt fragmentation into a cluster containing a small number (N <~ 10) of protostars and/or substellar objects. The subsequent evolution of the cluster is assumed to be dominated by dynamical interactions among cluster members, and this establishes the final properties of the binary and multiple systems. The characteristic scale of the fragmenting core is determined by the cloud initial conditions (such as temperature, angular momentum and mass), and we are able to relate the separation distributions of the final binary population to the properties of the star-forming core. Because the fragmentation scale immediately after the isothermal collapse is typically a factor of 3-10 too large, we conjecture that fragmentation into small clusters followed by dynamical evolution is required to account for the observed binary separation distributions. Differences in the environmental properties of the cores are expected to imprint differences on the characteristic dimensions of the binary systems they form. Recent observations of hierarchical systems, differences in binary characteristics among star forming regions and systematic variations in binary properties with primary mass can be interpreted in the context of this scenario.

Dynamical evolution of a fictitious population of binary Neptune Trojans

NASA Astrophysics Data System (ADS)

Brunini, Adrián

2018-03-01

We present numerical simulations of the evolution of a synthetic population of Binary Neptune Trojans, under the influence of the solar perturbations and tidal friction (the so-called Kozai cycles and tidal friction evolution). Our model includes the dynamical influence of the four giant planets on the heliocentric orbit of the binary centre of mass. In this paper, we explore the evolution of initially tight binaries around the Neptune L4 Lagrange point. We found that the variation of the heliocentric orbital elements due to the libration around the Lagrange point introduces significant changes in the orbital evolution of the binaries. Collisional processes would not play a significant role in the dynamical evolution of Neptune Trojans. After 4.5 × 109 yr of evolution, ˜50 per cent of the synthetic systems end up separated as single objects, most of them with slow diurnal rotation rate. The final orbital distribution of the surviving binary systems is statistically similar to the one found for Kuiper Belt Binaries when collisional evolution is not included in the model. Systems composed by a primary and a small satellite are more fragile than the ones composed by components of similar sizes.

An accessible echelle pipeline and its application to a binary star

NASA Astrophysics Data System (ADS)

Carmichael, Theron; Johnson, John Asher

2018-01-01

Nearly every star observed in the Galaxy has one or more companions that play an integral role in the evolution of the star. Whether it is a planet or another star, a companion opens up opportunities for unique forms of analysis to be done on a system. Some 2400 lightyears away, there is a 3-10 Myr old binary system called KH 15D, which not only includes two T Tauri K-type stars in a close orbit of 48 days, but also a truncated, coherently precessing warped disk in a circumbinary orbit.In binary systems, a double-lined spectroscopic binary may be observable in spectra. This is a spectrum that contains a mixture of each star's properties and manifests as two sets of spectral emission and absorption lines that correspond to each star. Slightly different is a single-lined spectroscopic binary, where only one set of spectral lines from one star is visible. The data of KH 15D are studied in the form of a double single-lined spectroscopic binary. This means that at two separate observing times, a single-lined spectroscopic binary is obtained from one of the stars of KH 15D. This is possible because of the circumbinary disk that blocks one star at a time from view.Here, we study this binary system with a combination of archival echelle data from the Keck Observatory and new echelle data from Las Campanas Observatory. This optical data is reduced with a new Python-based pipeline available on GitHub. The objective is to measure the mass function of the binary star and refine the current values of each star's properties.

Research on the Orbital Period of Massive Binaries

NASA Astrophysics Data System (ADS)

Zhao, E.; Qain, S.

2011-12-01

Massive binary is the kind of binary, whose spectral type is earlier than B5. Research on massive binary plays an important role in the mass and angular momentum transfer or loss between the components, and the evolution of binary. Some massive binaries are observed and analyzed, including O-type binary LY Aur, B-type contact binary RZ Pyx and B-type semi-detached binary AI Cru. It is found that all of their periods have a long-term increasing, which indicates that the system is undergoing a Case A slow mass transfer stage on the nuclear time-scale of the secondary. Moreover, analysis show a cyclic change of orbital period, which can be explained by the light-travel effect time of the third body.

A multicenter study confirms CD226 gene association with systemic sclerosis-related pulmonary fibrosis

PubMed Central

2012-01-01

Introduction CD226 genetic variants have been associated with a number of autoimmune diseases and recently with systemic sclerosis (SSc). The aim of this study was to test the influence of CD226 loci in SSc susceptibility, clinical phenotypes and autoantibody status in a large multicenter European population. Methods A total of seven European populations of Caucasian ancestry were included, comprising 2,131 patients with SSc and 3,966 healthy controls. Three CD226 single nucleotide polymorphisms (SNPs), rs763361, rs3479968 and rs727088, were genotyped using Taqman 5'allelic discrimination assays. Results Pooled analyses showed no evidence of association of the three SNPs, neither with the global disease nor with the analyzed subphenotypes. However, haplotype block analysis revealed a significant association for the TCG haplotype (SNP order: rs763361, rs34794968, rs727088) with lung fibrosis positive patients (PBonf = 3.18E-02 OR 1.27 (1.05 to 1.54)). Conclusion Our data suggest that the tested genetic variants do not individually influence SSc susceptibility but a CD226 three-variant haplotype is related with genetic predisposition to SSc-related pulmonary fibrosis. PMID:22531499

SWIR dispersive Raman spectroscopy for discrimination of normal and malignant kidney tissue (Conference Presentation)

NASA Astrophysics Data System (ADS)

Haifler, Miki; Pence, Isaac J.; Zisman, Amnon; Uzzo, Robert G.; Greenberg, Richard; Kutikov, Alexander; Smaldone, Marc; Chen, David; Viterbo, Rosalia; Ristau, Benjamin; Mahadevan-Jansen, Anita; Dumont, Alexander; Patil, Chetan A.

2017-02-01

Kidney cancer affects 65,000 new patients every. As computerized tomography became ubiquitous, the number of small, incidentally detected renal masses increased. About 6,000 benign cases are misclassified radiographically as malignant and removed surgically. Raman spectroscopy (RS) has been widely demonstrated for disease discrimination, however intense near-infrared auto-fluorescence of certain tissues (e.g kidney) can present serious challenges to bulk tissue diagnosis. A 1064nm excitation dispersive detection RS system demonstrated the ability to collect spectra with superior quality in tissues with strong auto-fluorescence. Our objective is to develop a 1064 nm dispersive detection RS system capable of differentiating normal and malignant renal tissue. We will report on the design and development of a clinical system for use in nephron sparing surgeries. We will present pilot data that has been collected from normal and malignant ex vivo kidney specimens using a benchtop RS system. A total of 93 measurements were collected from 12 specimens (6 Renal Cell Carcinoma, 6 Normal ). Spectral classification was performed using sparse multinomial logistic regression (SMLR). Correct classification by SMLR was obtained in 78% of the trials with sensitivity and specificity of 82% and 75% respectively. We will present the association of spectral features with biological indicators of healthy and diseased kidney tissue. Our findings indicate that 1064nm RS is a promising technique for differentiation of normal and malignant renal tissue. This indicates the potential for accurately separating healthy and cancerous tissues and suggests implications for utilizing RS for optical biopsy and surgical guidance in nephron sparing surgery.

Confirmation of TNIP1 but not RHOB and PSORS1C1 as systemic sclerosis risk factors in a large independent replication study

PubMed Central

Bossini-Castillo, Lara; Martin, Jose Ezequiel; Broen, Jasper; Simeon, Carmen P; Beretta, Lorenzo; Gorlova, Olga Y; Vonk, Madelon C; Ortego-Centeno, Norberto; Espinosa, Gerard; Carreira, Patricia; García de la Peña, Paloma; Oreiro, Natividad; Román-Ivorra, José Andrés; Castillo, María Jesús; González-Gay, Miguel A; Sáez-Comet, Luis; Castellví, Ivan; Schuerwegh, Annemie J; Voskuyl, Alexandre E; Hoffmann-Vold, Anna-Maria; Hesselstrand, Roger; Nordin, Annika; Lunardi, Claudio; Scorza, Raffaella; van Laar, Jacob M; Shiels, Paul G; Herrick, Ariane; Worthington, Jane; Fonseca, Carmen; Denton, Christopher; Tan, Filemon K; Arnett, Frank C; Assassi, Shervin; Koeleman, Bobby P; Mayes, Maureen D; Radstake, Timothy R D J; Martin, Javier

2013-01-01

Introduction A recent genome-wide association study in European systemic sclerosis (SSc) patients identified three loci (PSORS1C1, TNIP1 and RHOB) as novel genetic risk factors for the disease. The aim of this study was to replicate the previously mentioned findings in a large multicentre independent SSc cohort of Caucasian ancestry. Methods 4389 SSc patients and 7611 healthy controls from different European countries and the USA were included in the study. Six single nucleotide polymorphisms (SNP): rs342070, rs13021401 (RHOB), rs2233287, rs4958881, rs3792783 (TNIP1) and rs3130573 (PSORS1C1) were analysed. Overall significance was calculated by pooled analysis of all the cohorts. Haplotype analyses and conditional logistic regression analyses were carried out to explore further the genetic structure of the tested loci. Results Pooled analyses of all the analysed SNPs in TNIP1 revealed significant association with the whole disease (rs2233287 pMH=1.94×10−4, OR 1.19; rs4958881 pMH=3.26×10−5, OR 1.19; rs3792783 pMH=2.16×10−4, OR 1.19). These associations were maintained in all the subgroups considered. PSORS1C1 comparison showed association with the complete set of patients and all the subsets except for the anti-centromere-positive patients. However, the association was dependent on different HLA class II alleles. The variants in the RHOB gene were not associated with SSc or any of its subsets. Conclusions These data confirmed the influence of TNIP1 on an increased susceptibility to SSc and reinforced this locus as a common autoimmunity risk factor. PMID:22896740

Da Vinci Robotic Surgery in a Pediatric Hospital.

PubMed

Mattioli, Girolamo; Pini Prato, Alessio; Razore, Barbara; Leonelli, Lorenzo; Pio, Luca; Avanzini, Stefano; Boscarelli, Alessandro; Barabino, Paola; Disma, Nicola Massimo; Zanaboni, Clelia; Garzi, Alfredo; Martigli, Sofia Paola; Buffi, Nicolò Maria; Rosati, Ubaldo; Petralia, Paolo

2017-05-01

Since the use of robotic surgery (RS) revolutionized some adult surgery procedures such as radical prostatectomy, it has been progressively and increasingly introduced in pediatric surgery. The aim of this study is to evaluate how the Da Vinci ® Si HD technology impacts a pediatric public hospital and to define the use of a robotic system in pediatric surgery. We prospectively included patients older than 6 months of age undergoing RS or conventional minimal access surgery (MAS): Study period ranges between February 2015 and April 2016. Surgical indications were defined after a detailed disease-specific diagnostic work-up. We analyzed surgical outcomes and the most relevant economic aspects. The 30-day postoperative complications were evaluated and retrospectively collected in an electronic database. From February 2015 to April 2016, we performed 77 procedures with RS and 84 with conventional MAS in patients with a median age of 77 and 98 months at surgery and a median weight of 20 and 23 kg, respectively. Median operative times were 130 and 109 minutes, respectively. We observed 9.1% of complications in the RS group and 6% in the MAS group and the difference was not statistically significant. Of note, 8 out of 77 RS procedures would have been performed with open classic surgery in case of conversion or failure of RS. This initial experience confirms that RS is as safe and effective as conventional MAS. A number of selected procedures performed with RS would only benefit from this approach, as it is not suitable for conventional MAS. Although economically demanding, in particular for a pediatric hospital, we firmly believe that centralization of care would allow pediatric surgeons adopting RS to perform complex reconstructive surgical procedures with great advantages for the patients and a minimal increase in overall costs for the health system.

TNFSF4 polymorphisms are associated with systemic lupus erythematosus in the Malaysian population.

PubMed

Chua, K H; Ooh, Y Y; Chai, H C

2016-10-01

Tumour necrosis factor superfamily 4 (TNFSF4) gene has been reported to be associated with systemic lupus erythematosus (SLE) susceptibility due to its encoding for OX40L protein that can increase autoantibody production and cause imbalance of T-cell proliferation. The purpose of this study was to investigate the association of TNFSF4 rs2205960, rs1234315, rs8446748 and rs704840 with SLE in the Malaysian population. A total of 476 patients with SLE and 509 healthy controls were recruited. Real-time polymerase chain reaction (PCR) was applied to genotype the selected single nucleotide polymorphisms (SNPs). Allelic and genotypic frequencies of each SNP were calculated for each ethnic group, and association test was performed using logistic regression. The overall association of each SNP in Malaysian patients with SLE was determined with meta-analysis. The frequency of minor T allele of TNFSF4 rs2205960 was significant in Chinese and Indian patients with SLE, with P values of 0.05 (OR = 1.27, 95% CI: 1.00-1.61) and 0.004 (OR = 3.16, 95% CI: 1.41-7.05), respectively. Significant association of minor G allele of rs704840 with SLE was also observed in Chinese (P = 0.03, OR = 1.26, 95% CI: 1.02-1.56). However, after Bonferroni correction, only T allele of rs2205960 remained significantly associated with Indian cohort. Overall, minor G allele of rs704840 showed significant association with SLE in the Malaysian population with P values of 0.05 (OR = 1.20, 95% CI: 1.00-1.43). We suggested TNFSF4 rs704840 could be the potential SLE risk factors in the Malaysian population. © 2016 John Wiley & Sons Ltd.

Periodic Emission from the Gamma-ray Binary 1FGL J1018.6-5856

NASA Technical Reports Server (NTRS)

Celic, O.; Corbet, R. H. D.; Donato, D.; Ferrara, E. C.; Gehrels, N.; Harding, A. K.; Hays, E.; McEnery, J. E.; Thompson, D. J.; Troja, E.

2012-01-01

Gamma-ray binaries are stellar systems containing a neutron star or black hole with gamma-ray emission produced by an interaction between the components. These systems are rare, even though binary evolution models predict dozens in our Galaxy. A search for gamma-ray binaries with the Fermi Large Area Telescope (LAT) shows that IFGL JI018.6-5856 exhibits intensity and spectral modulation with a 16.6 day period. We identified a variable X-ray counterpart, which shows a sharp maximum coinciding with maximum gamma-ray emission, as well as an 06V f) star optical counterpart and a radio counterpart that is also apparently modulated on the orbital period. IFGL J1018.6-5856 is thus a gamma-ray binary, and its detection suggests the presence of other fainter binaries in the Galaxy.

The Großschwabhausen binary survey

NASA Astrophysics Data System (ADS)

Mugrauer, M.; Buder, S.; Reum, F.; Birth, A.

2017-01-01

Background: Since 2009, the Großschwabhausen binary survey is being carried out at the University Observatory Jena. This new imaging survey uses available time slots during photometric monitoring campaigns, caused by nonphotometric weather conditions, which often exhibit good atmospheric seeing. The goal of the project is to obtain current relative astrometric measurements of the binary systems that are listed in the Washington Visual Double Star Catalog. Materials and Methods: For the survey we use the Refraktor-Teleskop-Kamera at the University Observatory Jena to take imaging data of selected visual binary systems. Results: In this paper, we characterize the target sample of the survey, describe the imaging observations and the astrometric measurements including the astrometric calibration, and present the relative astrometric measures of 352 binaries that could be obtained during the course of the Großschwabhausen binary survey, so far.

Periodic emission from the gamma-ray binary 1FGL J1018.6-5856.

PubMed

Fermi LAT Collaboration; Ackermann, M; Ajello, M; Ballet, J; Barbiellini, G; Bastieri, D; Belfiore, A; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bregeon, J; Brigida, M; Bruel, P; Buehler, R; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Cavazzuti, E; Cecchi, C; Çelik, Ö; Charles, E; Chaty, S; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Corbel, S; Corbet, R H D; Cutini, S; de Luca, A; den Hartog, P R; de Palma, F; Dermer, C D; Digel, S W; do Couto e Silva, E; Donato, D; Drell, P S; Drlica-Wagner, A; Dubois, R; Dubus, G; Favuzzi, C; Fegan, S J; Ferrara, E C; Focke, W B; Fortin, P; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giglietto, N; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Grenier, I A; Grove, J E; Guiriec, S; Hadasch, D; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Hill, A B; Hughes, R E; Jóhannesson, G; Johnson, A S; Johnson, T J; Kamae, T; Katagiri, H; Kataoka, J; Kerr, M; Knödlseder, J; Kuss, M; Lande, J; Longo, F; Loparco, F; Lovellette, M N; Lubrano, P; Mazziotta, M N; McEnery, J E; Michelson, P F; Mitthumsiri, W; Mizuno, T; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nakamori, T; Naumann-Godo, M; Norris, J P; Nuss, E; Ohno, M; Ohsugi, T; Okumura, A; Omodei, N; Orlando, E; Ozaki, M; Paneque, D; Parent, D; Pesce-Rollins, M; Pierbattista, M; Piron, F; Pivato, G; Porter, T A; Rainò, S; Rando, R; Razzano, M; Reimer, A; Reimer, O; Ritz, S; Romani, R W; Roth, M; Saz Parkinson, P M; Sgrò, C; Siskind, E J; Spandre, G; Spinelli, P; Suson, D J; Takahashi, H; Tanaka, T; Thayer, J G; Thayer, J B; Thompson, D J; Tibaldo, L; Tinivella, M; Torres, D F; Tosti, G; Troja, E; Uchiyama, Y; Usher, T L; Vandenbroucke, J; Vianello, G; Vitale, V; Waite, A P; Winer, B L; Wood, K S; Wood, M; Yang, Z; Zimmer, S; Coe, M J; Di Mille, F; Edwards, P G; Filipović, M D; Payne, J L; Stevens, J; Torres, M A P

2012-01-13

Gamma-ray binaries are stellar systems containing a neutron star or black hole, with gamma-ray emission produced by an interaction between the components. These systems are rare, even though binary evolution models predict dozens in our Galaxy. A search for gamma-ray binaries with the Fermi Large Area Telescope (LAT) shows that 1FGL J1018.6-5856 exhibits intensity and spectral modulation with a 16.6-day period. We identified a variable x-ray counterpart, which shows a sharp maximum coinciding with maximum gamma-ray emission, as well as an O6V((f)) star optical counterpart and a radio counterpart that is also apparently modulated on the orbital period. 1FGL J1018.6-5856 is thus a gamma-ray binary, and its detection suggests the presence of other fainter binaries in the Galaxy.

Periodic Emission from the Gamma-Ray Binary 1FGL J1018.6-5856

NASA Technical Reports Server (NTRS)

2012-01-01

Gamma-ray binaries are stellar systems containing a neutron star or black hole, with gamma-ray emission produced by an interaction between the components. These systems are rare, even though binary evolution models predict dozens in our Galaxy, A search for gamma-ray binaries with the Fermi Large Area Telescope (LAT) shows that 1FGL ]1018.6-5856 exhibits intensity and spectral modulation with a 16.6 day period. We identified a variable x-ray counterpart, which shows a sharp maximum coinciding with maximum gamma-ray emission, as well as an O6V((f)) star optical counterpart and a radio counterpart that is also apparently modulated on the orbital period. 1FGL ]1018.6-5856 is thus a gamma-ray binary, and its detection suggests the presence of other fainter binaries in the Galaxy.

Brown Dwarf Binaries from Disintegrating Triple Systems

NASA Astrophysics Data System (ADS)

Reipurth, Bo; Mikkola, Seppo

2015-04-01

Binaries in which both components are brown dwarfs (BDs) are being discovered at an increasing rate, and their properties may hold clues to their origin. We have carried out 200,000 N-body simulations of three identical stellar embryos with masses drawn from a Chabrier IMF and embedded in a molecular core. The bodies are initially non-hierarchical and undergo chaotic motions within the cloud core, while accreting using Bondi-Hoyle accretion. The coupling of dynamics and accretion often leads to one or two dominant bodies controlling the center of the cloud core, while banishing the other(s) to the lower-density outskirts, leading to stunted growth. Eventually each system transforms either to a bound hierarchical configuration or breaks apart into separate single and binary components. The orbital motion is followed for 100 Myr. In order to illustrate 200,000 end-states of such dynamical evolution with accretion, we introduce the “triple diagnostic diagram,” which plots two dimensionless numbers against each other, representing the binary mass ratio and the mass ratio of the third body to the total system mass. Numerous freefloating BD binaries are formed in these simulations, and statistical properties are derived. The separation distribution function is in good correspondence with observations, showing a steep rise at close separations, peaking around 13 AU and declining more gently, reaching zero at separations greater than 200 AU. Unresolved BD triple systems may appear as wider BD binaries. Mass ratios are strongly peaked toward unity, as observed, but this is partially due to the initial assumptions. Eccentricities gradually increase toward higher values, due to the lack of viscous interactions in the simulations, which would both shrink the orbits and decrease their eccentricities. Most newborn triple systems are unstable and while there are 9209 ejected BD binaries at 1 Myr, corresponding to about 4% of the 200,000 simulations, this number has grown to 15,894 at 100 Myr (˜8%). The total binary fraction among freefloating BDs is 0.43, higher than indicated by current observations, which, however, are still incomplete. Also, the gradual breakup of higher-order multiples leads to many more singles, thus lowering the binary fraction. The main threat to newly born triple systems is internal instabilities, not external perturbations. At 1 Myr there are 1325 BD binaries still bound to a star, corresponding to 0.66% of the simulations, but only 253 (0.13%) are stable on timescales >100 Myr. These simulations indicate that dynamical interactions in newborn triple systems of stellar embryos embedded in and accreting from a cloud core naturally form a population of freefloating BD binaries, and this mechanism may constitute a significant pathway for the formation of BD binaries.

The PyCBC search for binary black hole coalescences in Advanced LIGO's first observing run

NASA Astrophysics Data System (ADS)

Willis, Joshua; LIGO Scientific Collaboration

2017-01-01

Advanced LIGO's first observing run saw the first detections of binary black hole coalescences. We describe the PyCBC matched filter analysis, and the results of that search for binary systems with total mass up to 100 solar masses. This is a matched filter search for general-relativistic signals from binary black hole systems. Two signals, GW150914 and GW151226, were identified with very high significance, and a third possible signal, LVT151012, was found, though at much lower significance. Supported by NSF award PHY-1506254.

SEARCHING FOR BINARY Y DWARFS WITH THE GEMINI MULTI-CONJUGATE ADAPTIVE OPTICS SYSTEM (GeMS)

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

Opitz, Daniela; Tinney, C. G.; Faherty, Jacqueline K.

The NASA Wide-field Infrared Survey Explorer (WISE) has discovered almost all the known members of the new class of Y-type brown dwarfs. Most of these Y dwarfs have been identified as isolated objects in the field. It is known that binaries with L- and T-type brown dwarf primaries are less prevalent than either M-dwarf or solar-type primaries, they tend to have smaller separations and are more frequently detected in near-equal mass configurations. The binary statistics for Y-type brown dwarfs, however, are sparse, and so it is unclear if the same trends that hold for L- and T-type brown dwarfs alsomore » hold for Y-type ones. In addition, the detection of binary companions to very cool Y dwarfs may well be the best means available for discovering even colder objects. We present results for binary properties of a sample of five WISE Y dwarfs with the Gemini Multi-Conjugate Adaptive Optics System. We find no evidence for binary companions in these data, which suggests these systems are not equal-luminosity (or equal-mass) binaries with separations larger than ∼0.5–1.9 AU. For equal-mass binaries at an age of 5 Gyr, we find that the binary binding energies ruled out by our observations (i.e., 10{sup 42} erg) are consistent with those observed in previous studies of hotter ultra-cool dwarfs.« less

Binary asteroid population. 2. Anisotropic distribution of orbit poles of small, inner main-belt binaries

NASA Astrophysics Data System (ADS)

Pravec, P.; Scheirich, P.; Vokrouhlický, D.; Harris, A. W.; Kušnirák, P.; Hornoch, K.; Pray, D. P.; Higgins, D.; Galád, A.; Világi, J.; Gajdoš, Š.; Kornoš, L.; Oey, J.; Husárik, M.; Cooney, W. R.; Gross, J.; Terrell, D.; Durkee, R.; Pollock, J.; Reichart, D. E.; Ivarsen, K.; Haislip, J.; LaCluyze, A.; Krugly, Yu. N.; Gaftonyuk, N.; Stephens, R. D.; Dyvig, R.; Reddy, V.; Chiorny, V.; Vaduvescu, O.; Longa-Peña, P.; Tudorica, A.; Warner, B. D.; Masi, G.; Brinsfield, J.; Gonçalves, R.; Brown, P.; Krzeminski, Z.; Gerashchenko, O.; Shevchenko, V.; Molotov, I.; Marchis, F.

2012-03-01

Our photometric observations of 18 main-belt binary systems in more than one apparition revealed a strikingly high number of 15 having positively re-observed mutual events in the return apparitions. Our simulations of the survey showed that it cannot be due to an observational selection effect and that the data strongly suggest that poles of mutual orbits between components of binary asteroids in the primary size range 3-8 km are not distributed randomly: The null hypothesis of an isotropic distribution of the orbit poles is rejected at a confidence level greater than 99.99%. Binary orbit poles concentrate at high ecliptic latitudes, within 30° of the poles of the ecliptic. We propose that the binary orbit poles oriented preferentially up/down-right are due to either of the two processes: (i) the YORP tilt of spin axes of their parent bodies toward the asymptotic states near obliquities 0° and 180° (pre-formation mechanism) or (ii) the YORP tilt of spin axes of the primary components of already formed binary systems toward the asymptotic states near obliquities 0° and 180° (post-formation mechanism). The alternative process of elimination of binaries with poles closer to the ecliptic by dynamical instability, such as the Kozai effect due to gravitational perturbations from the Sun, does not explain the observed orbit pole concentration. This is because for close binary asteroid systems, the gravitational effects of primary’s irregular shape dominate the solar-tide effect.

Trans*versing the DMZ: A Non-Binary Autoethnographic Exploration of Gender and Masculinity

ERIC Educational Resources Information Center

Stewart, Dafina-Lazarus

2017-01-01

Using an abductive, critical-poststructuralist autoethnographic approach, I consider the ways in which masculine of centre, non-binary/genderqueer trans* identities transverse the poles of socializing binary gender systems, structures, and norms which inform higher education. In this paper, I assert that non-binary genderqueer identities are…

Binary Star Fractions from the LAMOST DR4

NASA Astrophysics Data System (ADS)

Tian, Zhi-Jia; Liu, Xiao-Wei; Yuan, Hai-Bo; Chen, Bing-Qiu; Xiang, Mao-Sheng; Huang, Yang; Wang, Chun; Zhang, Hua-Wei; Guo, Jin-Cheng; Ren, Juan-Juan; Huo, Zhi-Ying; Yang, Yong; Zhang, Meng; Bi, Shao-Lan; Yang, Wu-Ming; Liu, Kang; Zhang, Xian-Fei; Li, Tan-Da; Wu, Ya-Qian; Zhang, Jing-Hua

2018-05-01

Stellar systems composed of single, double, triple or higher-order systems are rightfully regarded as the fundamental building blocks of the Milky Way. Binary stars play an important role in formation and evolution of the Galaxy. Through comparing the radial velocity variations from multi-epoch observations, we analyze the binary fraction of dwarf stars observed with LAMOST. Effects of different model assumptions, such as orbital period distributions on the estimate of binary fractions, are investigated. The results based on log-normal distribution of orbital periods reproduce the previous complete analyses better than the power-law distribution. We find that the binary fraction increases with T eff and decreases with [Fe/H]. We first investigate the relation between α-elements and binary fraction in such a large sample as provided by LAMOST. The old stars with high [α/Fe] dominate with a higher binary fraction than young stars with low [α/Fe]. At the same mass, earlier forming stars possess a higher binary fraction than newly forming ones, which may be related with evolution of the Galaxy.

Candidates of eclipsing multiples based on extraneous eclipses on binary light curves: KIC 7622486, KIC 7668648, KIC 7670485 and KIC 8938628

NASA Astrophysics Data System (ADS)

Zhang, Jia; Qian, Sheng-Bang; He, Jian-Duo

2017-02-01

Four candidates of eclipsing multiples, based on new extraneous eclipses found on Kepler binary light curves, are presented and studied. KIC 7622486 is a double eclipsing binary candidate with orbital periods of 2.2799960 d and 40.246503 d. The two binary systems do not eclipse each other in the line of sight, but there is mutual gravitational influence between them which leads to the small but definite eccentricity of 0.0035(0.0022) associated with the short 2.2799960 d period orbit. KIC 7668648 is a hierarchical quadruple system candidate, with two sets of solid 203 ± 5 d period extraneous eclipses and another independent set of extraneous eclipses. A clear and credible extraneous eclipse is found on the binary light curve of KIC 7670485 which makes it a triple system candidate. Two sets of extraneous eclipses with periods of about 390 d and 220 d are found on KIC 8938628 binary curves, which not only confirm the previous conclusion of the 388.5 ± 0.3 triple system, but also indicate new additional objects that make KIC 8938628 a hierarchical quadruple system candidate. The results from these four candidates will contribute to the field of eclipsing multiples.

Colliding Winds in Massive Binaries

NASA Astrophysics Data System (ADS)

Thaller, M. L.

1998-12-01

In close binary systems of massive stars, the individual stellar winds will collide and form a bow shock between the stars, which may have significant impact on the mass-loss and evolution of the system. The existence of such a shock can be established through orbital-phase related variations in the UV resonance lines and optical emission lines. High density regions near the shock will produce Hα and Helium I emission which can be used to map the mass-flow structure of the system. The shock front between the stars may influence the balance of mass-loss versus mass-transfer in massive binary evolution, as matter lost to one star due to Roche lobe overflow may hit the shock and be deflected before it can accrete onto the surface of the other star. I have completed a high-resolution spectroscopic survey of 37 massive binaries, and compared the incidence and strength of emission to an independent survey of single massive stars. Binary stars show a statistically significant overabundance of optical emission, especially when one of the binary stars is in either a giant or supergiant phase of evolution. Seven systems in my survey exhibited clear signs of orbital phase related emission, and for three of the stars (HD 149404, HD 152248, and HD 163181), I present qualitative models of the mass-flow dynamics of the systems.

Vulcan Identification of Eclipsing Binaries in the Kepler Field of View

NASA Astrophysics Data System (ADS)

Mjaseth, Kimberly; Batalha, N.; Borucki, W.; Caldwell, D.; Latham, D.; Martin, K. R.; Rabbette, M.; Witteborn, F.

2007-05-01

We report the discovery of 236 new eclipsing binary stars located in and around the field of view of the Kepler Mission. The binaries were identified from photometric light curves from the Vulcan exoplanet transit survey. The Vulcan camera is comprised of a modest aperture (10cm) f/2.8 Canon lens focusing a 7° x 7° field of view onto a 4096 x 4096 Kodak CCD. The system yields an hour-to-hour relative precision of 0.003 on 12th magnitude stars and saturates at 9th magnitude. The binaries have magnitudes in the range of 9.5 < V < 13.5 and periods ranging from 0.5 to 13 days. The milli-magnitude photometric precision allows detection of transits as shallow as 1%. The catalog contains a total of 273 eclipsing binary stars, including detached systems (high and low mass ratio), contact binaries, and triple systems. We present the derived orbital/transit properties, light curves, and stellar properties for selected targets. In addition, we summarize the results of radial velocity follow-up work. Support for this work came from NASA's Discovery Program and NASA's Origins of the Solar System Program.

Investigating the association between polymorphisms in connective tissue growth factor and susceptibility to colon carcinoma.

PubMed

Ahmad, Abrar; Askari, Shlear; Befekadu, Rahel; Hahn-Strömberg, Victoria

2015-04-01

There have been numerous studies on the gene expression of connective tissue growth factor (CTGF) in colorectal cancer, however very few have investigated polymorphisms in this gene. The present study aimed to determine whether single nucleotide polymorphisms (SNPs) in the CTGF gene are associated with a higher susceptibility to colon cancer and/or an invasive tumor growth pattern. The CTGF gene was genotyped for seven SNPs (rs6918698, rs1931002, rs9493150, rs12526196, rs12527705, rs9399005 and rs12527379) by pyrosequencing. Formalin‑fixed paraffin‑embedded tissue samples (n=112) from patients diagnosed with colon carcinoma, and an equal number of blood samples from healthy controls, were selected for genomic DNA extraction. The complexity index was measured using images of tumor samples (n=64) stained for cytokeratin‑8. The images were analyzed and correlated with the identified CTGF SNPs and clinicopathological parameters of the patients, including age, gender, tumor penetration, lymph node metastasis, systemic metastasis, differentiation and localization of tumor. It was demonstrated that the frequency of the SNP rs6918698 GG genotype was significantly associated (P=0.05) with an increased risk of colon cancer, as compared with the GC and CC genotypes. The other six SNPs (rs1931002, rs9493150, rs12526196, rs12527705, rs9399005 and rs12527379) exhibited no significant difference in the genotype and allele frequencies between patients diagnosed with colon carcinoma and the normal healthy population. A trend was observed between genotype variation at rs6918698 and the complexity index (P=0.052). The complexity index and genotypes for any of the studied SNPs were not significantly correlated with clinical or pathological parameters of the patients. These results indicate that the rs6918698 GG genotype is associated with an increased risk of developing colon carcinoma, and genetic variations at the rs6918698 are associated with the growth pattern of the tumor. The present results may facilitate the identification of potential biomarkers of the disease in addition to drug targets.

VX Her: Eclipsing Binary System or Single Variable Star

NASA Astrophysics Data System (ADS)

Perry, Kathleen; Castelaz, Michael; Henson, Gary; Boghozian, Andrew

2015-01-01

VX Her is a pulsating variable star with a period of .4556504 days. It is believed to be part of an eclipsing binary system (Fitch et al. 1966). This hypothesis originated from Fitch seeing VX Her's minimum point on its light curve reaching a 0.7 magnitude fainter than normal and remaining that way for nearly two hours. If VX Her were indeed a binary system, I would expect to see similar results with a fainter minimum and a broader, more horizontal dip. Having reduced and analyzed images from the Southeastern Association for Research in Astronomy Observatory in Chile and Kitt Peak, as well as images from a 0.15m reflector at East Tennessee State University, I found that VX Her has the standard light curve of the prototype variable star, RR Lyrae. Using photometry, I found no differing features in its light curve to suggest that it is indeed a binary system. However, more observations are needed in case VX Her is a wide binary.

Estimating gravitational radiation from super-emitting compact binary systems

NASA Astrophysics Data System (ADS)

Hanna, Chad; Johnson, Matthew C.; Lehner, Luis

2017-06-01

Binary black hole mergers are among the most violent events in the Universe, leading to extreme warping of spacetime and copious emission of gravitational radiation. Even though black holes are the most compact objects they are not necessarily the most efficient emitters of gravitational radiation in binary systems. The final black hole resulting from a binary black hole merger retains a significant fraction of the premerger orbital energy and angular momentum. A nonvacuum system can in principle shed more of this energy than a black hole merger of equivalent mass. We study these super-emitters through a toy model that accounts for the possibility that the merger creates a compact object that retains a long-lived time-varying quadrupole moment. This toy model may capture the merger of (low mass) neutron stars, but it may also be used to consider more exotic compact binaries. We hope that this toy model can serve as a guide to more rigorous numerical investigations into these systems.

Collapsing Binary Asteroids With YORP And BYORP

NASA Astrophysics Data System (ADS)

Taylor, Patrick A.

2012-05-01

A separated binary system may be collapsed to contact via the removal of angular momentum from the system until a viable tidal end state no longer exists. The thermal YORP and BYORP effects are both capable of removing angular momentum from the system, by spin-down of the components and shrinking the mutual orbit, respectively. The YORP effect, with strength of order that measured for (1862) Apollo [1], can collapse a binary system with equal-mass components in as little as tens of thousands of years (depending on the initial angular momentum), while smaller secondaries require two or more orders of magnitude longer to collapse. BYORP, with a BYORP coefficent of 0.001 [2], is less efficient, especially for smaller secondaries. By these methods, only near-Earth binaries with large mass ratios can collapse within a dynamical lifetime, a population of which is observed by radar with a frequency comparable to separated binaries. [1] Kaasalainen et al., 2007, Nature 446, 420-422. [2] McMahon and Scheeres, 2010, Icarus 209, 494-509.

The critical binary star separation for a planetary system origin of white dwarf pollution

NASA Astrophysics Data System (ADS)

Veras, Dimitri; Xu, Siyi; Rebassa-Mansergas, Alberto

2018-01-01

The atmospheres of between one quarter and one half of observed single white dwarfs in the Milky Way contain heavy element pollution from planetary debris. The pollution observed in white dwarfs in binary star systems is, however, less clear, because companion star winds can generate a stream of matter which is accreted by the white dwarf. Here, we (i) discuss the necessity or lack thereof of a major planet in order to pollute a white dwarf with orbiting minor planets in both single and binary systems, and (ii) determine the critical binary separation beyond which the accretion source is from a planetary system. We hence obtain user-friendly functions relating this distance to the masses and radii of both stars, the companion wind, and the accretion rate on to the white dwarf, for a wide variety of published accretion prescriptions. We find that for the majority of white dwarfs in known binaries, if pollution is detected, then that pollution should originate from planetary material.

Shaping planetary nebulae with jets in inclined triple stellar systems

NASA Astrophysics Data System (ADS)

Akashi, Muhammad; Soker, Noam

2017-10-01

We conduct three-dimensional hydrodynamical simulations of two opposite jets launched obliquely to the orbital plane around an asymptotic giant branch (AGB) star and within its dense wind, and demonstrate the formation of a `messy' planetary nebula (PN), namely, a PN lacking any type of symmetry (highly irregular). In building the initial conditions we assume that a tight binary system orbits the AGB star, and that the orbital plane of the tight binary system is inclined to the orbital plane of binary system and the AGB star. We further assume that the accreted mass onto the tight binary system forms an accretion disk around one of the stars, and that the plane of the disk is in between the two orbital planes. The highly asymmetrical lobes that we obtain support the notion that messy PNe might be shaped by triple stellar systems.

Binary interaction dominates the evolution of massive stars.

PubMed

Sana, H; de Mink, S E; de Koter, A; Langer, N; Evans, C J; Gieles, M; Gosset, E; Izzard, R G; Le Bouquin, J-B; Schneider, F R N

2012-07-27

The presence of a nearby companion alters the evolution of massive stars in binary systems, leading to phenomena such as stellar mergers, x-ray binaries, and gamma-ray bursts. Unambiguous constraints on the fraction of massive stars affected by binary interaction were lacking. We simultaneously measured all relevant binary characteristics in a sample of Galactic massive O stars and quantified the frequency and nature of binary interactions. More than 70% of all massive stars will exchange mass with a companion, leading to a binary merger in one-third of the cases. These numbers greatly exceed previous estimates and imply that binary interaction dominates the evolution of massive stars, with implications for populations of massive stars and their supernovae.

High-field superconductivity in the Nb-Ti-Zr ternary system

NASA Astrophysics Data System (ADS)

Ralls, K. M.; Rose, R. M.; Wulff, J.

1980-06-01

Resistive critical current densities, critical fields, and normal-state electrical resistivities were obtained at 4.2 °K for 55 alloys in the Nb-Ti-Zr ternary alloy system, excepting Ti-Zr binary compositions. The resistive critical field as a function of ternary composition has a saddle point between the Nb-Ti and Nb-Zr binaries, so that ternary alloying in this system is not expected to result in higher critical fields than the binary alloys.

Planetary Systems Dynamics Eccentric patterns in debris disks & Planetary migration in binary systems

NASA Astrophysics Data System (ADS)

Faramaz, V.; Beust, H.; Augereau, J.-C.; Bonsor, A.; Thébault, P.; Wu, Y.; Marshall, J. P.; del Burgo, C.; Ertel, S.; Eiroa, C.; Montesinos, B.; Mora, A.

2014-01-01

We present some highlights of two ongoing investigations that deal with the dynamics of planetary systems. Firstly, until recently, observed eccentric patterns in debris disks were found in young systems. However recent observations of Gyr-old eccentric debris disks leads to question the survival timescale of this type of asymmetry. One such disk was recently observed in the far-IR by the Herschel Space Observatory around ζ2 Reticuli. Secondly, as a binary companion orbits a circumprimary disk, it creates regions where planet formation is strongly handicapped. However, some planets were detected in this zone in tight binary systems (γ Cep, HD 196885). We aim to determine whether a binary companion can affect migration such that planets are brought in these regions and focus in particular on the planetesimal-driven migration mechanism.

A systems immunology approach identifies the collective impact of 5 miRs in Th2 inflammation.

PubMed

Kılıç, Ayşe; Santolini, Marc; Nakano, Taiji; Schiller, Matthias; Teranishi, Mizue; Gellert, Pascal; Ponomareva, Yuliya; Braun, Thomas; Uchida, Shizuka; Weiss, Scott T; Sharma, Amitabh; Renz, Harald

2018-06-07

Allergic asthma is a chronic inflammatory disease dominated by a CD4+ T helper 2 (Th2) cell signature. The immune response amplifies in self-enforcing loops, promoting Th2-driven cellular immunity and leaving the host unable to terminate inflammation. Posttranscriptional mechanisms, including microRNAs (miRs), are pivotal in maintaining immune homeostasis. Since an altered expression of various miRs has been associated with T cell-driven diseases, including asthma, we hypothesized that miRs control mechanisms ensuring Th2 stability and maintenance in the lung. We isolated murine CD4+ Th2 cells from allergic inflamed lungs and profiled gene and miR expression. Instead of focusing on the magnitude of miR differential expression, here we addressed the secondary consequences for the set of molecular interactions in the cell, the interactome. We developed the Impact of Differential Expression Across Layers, a network-based algorithm to prioritize disease-relevant miRs based on the central role of their targets in the molecular interactome. This method identified 5 Th2-related miRs (mir27b, mir206, mir106b, mir203, and mir23b) whose antagonization led to a sharp reduction of the Th2 phenotype. Overall, a systems biology tool was developed and validated, highlighting the role of miRs in Th2-driven immune response. This result offers potentially novel approaches for therapeutic interventions.

Genetic polymorphisms of IL-18 rs1946518 and IL-1β rs16944 are associated with prognosis and survival of acute myeloid leukemia.

PubMed

Wang, Hong; Hua, Mingqiang; Wang, Shukang; Yu, Jie; Chen, Chen; Zhao, Xueyun; Zhang, Chen; Zhong, Chaoqin; Wang, Ruiqing; He, Na; Hou, Ming; Ma, Daoxin

2017-03-01

Though the pathogenesis of AML is still unknown, accumulating evidence revealed that immune response plays a vital part in it. NLRP3 inflammasome as a component of immune system has been found related to several cancers. The single nucleotide polymorphisms (SNPs) of NLRP3 inflammasome genes may be related to pathogenesis and prognosis of AML. We determined polymorphisms of NLRP3 (rs35829419), CARD8 (rs2043211), IL-1β (rs16944), IL-18 (rs1946518) and NF-κB -94 ins/del ATTG in de novo AML patients to find out whether they play roles in the susceptibility and severity of AML. In our study, 383 AML cases and 300 randomly selected healthy individuals were examined for the polymorphisms and expression of NLRP3 genes. IL-1β (rs16944) polymorphism in different risk AML subgroups was found statistically different, with more GA genotype in favorable-risk cytogenetics group. We also demonstrated that the bone marrow blasts of patients carrying IL-18 (rs1946518) GG or GT genotype were higher than patients of TT genotype. IL-18 plasma level of patients with IL-18 (rs1946518) GT or TT genotype was higher than GG genotype. Moreover, the GT genotype of IL-18 (rs1946518) led to statistically poorer AML-specific survival. IL-1β (rs16944) and IL-18 (rs1946518) may be served as potential predictors for AML.

Association of the angiotensinogen gene polymorphism with atherosclerosis and its risk traits in the Saudi population

PubMed Central

2013-01-01

Background Angiotensinogen (AGT) constitutes a central component of the renin-angiotensin system that controls the systemic blood pressure and several other cardiovascular functions and may play an important role in atherosclerosis pathways. In this study, we employed TaqMan genotyping assays to evaluate the role of 8 AGT variants in primary hypertension (HTN), type 2 diabetes mellitus (T2DM), and obesity as a possible trigger of coronary artery disease (CAD) in a population of 4615 angiographed native Saudi individuals. Methods Linkage analysis was done by using the Affymetrix Gene Chip array, sequencing by using the MegaBACE DNA analysis system and genotyping accomplished by TaqMan chemistry using the Applied Biosystem real-time Prism 7900HT Sequence Detection System. Results Six variants, rs2067853 GG [Odds ratio(95% Confidence Interval) = 1.44(1.17-1.78); p = 0.001], rs7079 [1.49(1.20-1.85); p < 0.0001], rs699 G [1.19(1.08-1.13); p < 0.0001], rs3789679 A [1.51(1.14-1.99); p = 0.004], rs2148582 GG [1.31(1.11-1.55); p = 0.002] and rs5051 TC + CC [1.32(1.13-1.60); p = 0.001] conferred risk for HTN (3521 cases versus 1094 controls). The rs2067853 (p = 0.042), rs699G (p = 0.007) and rs5051 (p = 0.051) also conferred risk for myocardial infarction (MI; 2982 vs 1633), while rs3789679 A (p < 0.0001) and GA + AA (p < 0.0001) as well as rs4762G (p = 0.019) were associated with obesity (1576 vs 2458). However, while these variants appeared to be also associated with CAD (2323 vs 2292), only the rs7079G (p = 0.035) retained its significant relationship. Interestingly, among the haplotypes constructed from these SNPs, the baseline 8-mer haplotype, GGTGGGGT (χ2 = 7.02; p = 0.0081) and another GGCGGAGT (χ2 = 5.10; p = 0.024), together with several of their derivatives were associated with HTN. T2DM was associated with two 8-mer haplotypes, GGTAGGAC (χ2 = 5.66; p = 0.017) and ATTGAGAC (χ2 = 5.93; p = 0.015), obesity with GGCGGAGT (χ2 = 9.49; p = 0.0021) and MI was linked to ATTGGGAC (χ2 = 6.68; p = 0.010) and GGTGGGAT (χ2 = 4.25; p = 0.039). Furthermore, several causative haplotypes were also shared among the risk traits as well as with CAD. Conclusion These results point to AGT as independently conferring risk for various cardiovascular traits, and possibly interacting with these traits in events leading to atherosclerosis. PMID:23497386

Spin Evolution of Stellar Progenitors in Compact Binaries

NASA Astrophysics Data System (ADS)

Steinle, Nathan; Kesden, Michael

2018-01-01

Understanding the effects of various processes on the spins of stellar progenitors in compact binary systems is important for modeling the binary’s evolution and thus for interpreting the gravitational radiation emitted during inspiral and merger. Tides, winds, and natal kicks can drastically modify the binary parameters: tidal interactions increase the spin magnitudes, align the spins with the orbital angular momentum, and circularize the orbit; stellar winds decrease the spin magnitudes and cause mass loss; and natal kicks can misalign the spins and orbital angular momentum or even disrupt the binary. Also, during Roche lobe overflow, the binary may experience either stable mass transfer or common envelope evolution. The former can lead to a mass ratio reversal and alter the component spins, while the latter can dramatically shrink the binary separation. For a wide range of physically reasonable stellar-evolution scenarios, we compare the timescales of these processes to assess their relative contributions in determining the initial spins of compact binary systems.

On the Lack of Circumbinary Planets Orbiting Isolated Binary Stars

NASA Astrophysics Data System (ADS)

Fleming, David; Barnes, Rory; Graham, David E.; Luger, Rodrigo; Quinn, Thomas R.

2018-04-01

To date, no binary star system with an orbital period less than 7.5 days has been observed to host a circumbinary planet (CBP), a puzzling observation given the thousands of binary stars with orbital periods < 10 days discovered by the Kepler mission (Kirk et al., 2016) and the observational biases that favor their detection (Munoz & Lai, 2015). We outline a mechanism that explains the observed lack of CBPs via coupled stellar-tidal evolution of isolated binary stars. Tidal forces between low-mass, short-period binary stars on the pre-main sequence slow the stellar rotations, transferring rotational angular momentum to the orbit as the stars approach the tidally locked state. This transfer increases the binary orbital period, expanding the region of dynamical instability around the binary, and destabilizing CBPs that tend to preferentially orbit just beyond the initial dynamical stability limit. After the stars tidally lock, we find that angular momentum loss due to magnetic braking can significantly shrink the binary orbit, and hence the region of dynamical stability, over time impacting where surviving CBPs are observed relative to the boundary. We perform simulations over a wide range of parameter space and find that the expansion of the instability region occurs for most plausible initial conditions and that in some cases, the stability semi-major axis doubles from its initial value. We examine the dynamical and observable consequences of a CBP falling within the dynamical instability limit by running N-body simulations of circumbinary planetary systems and find that typically, at least one planet is ejected from the system. We apply our theory to the shortest period Kepler binary that possesses a CBP, Kepler-47, and find that its existence is consistent with our model. Under conservative assumptions, we find that coupled stellar-tidal evolution of pre-main sequence binary stars removes at least one close-in CBP in 87% of multi-planet circumbinary systems.

Primary Surface Particle Motion as a Mechanism for YORP-Driven Binary Asteroid Evolution

NASA Astrophysics Data System (ADS)

Fahnestock, Eugene G.; Scheeres, D. J.

2008-09-01

Within the largest class of binary asteroid systems -- asynchronous binaries typified by 1999 KW4 -- we hypothesize continued YORP spin-up of the rapidly rotating primary leads to recurring episodic lofting motion of primary equator regolith. We theorize this is a mechanism for transporting YORP-injected angular momentum from primary spin into the mutual orbit. This both enables binary primaries to continue to spin at near surface fission rates and produces continued orbit expansion on time scales several times faster than expansion predicted by tidal dissipation alone. This is distinct from the Binary Yorp (BYORP) phenomenon, not studied in this work but to be added to it later. We evaluate our hypotheses using a combination of techniques for an example binary system. First high-fidelity dynamic simulation of surface-originating particles in the full-detail gravity field of the binary components, themselves propagated according to the full two body problem, gives particle final disposition (return impact, transfer impact, escape). Trajectory end states found for regolith lofted at different initial primary spin rates and relative poses are collected into probability matrices, allowing probabilistic propagation of surface particles for long durations at low computational cost. We track changes to mass, inertia dyad, rotation state, and centroid position and velocity for each component in response to this mapped particle motion. This allows tracking of primary, secondary, and mutual orbit angular momenta over time, clearly demonstrating the angular momentum transfer mechanism and validating our hypotheses. We present current orbit expansion rates and estimated orbit size doubling times consistent with this mechanism, for a few binary systems. We also discuss ramifications of this type of rapid binary evolution towards separation, including the frequency with which "divorced binaries" on similar heliocentric orbits are produced, formation of triple systems such as 2001 SN263, and separation timescale dependence on heliocentric distance.

Generation of two-dimensional binary mixtures in complex plasmas

NASA Astrophysics Data System (ADS)

Wieben, Frank; Block, Dietmar

2016-10-01

Complex plasmas are an excellent model system for strong coupling phenomena. Under certain conditions the dust particles immersed into the plasma form crystals which can be analyzed in terms of structure and dynamics. Previous experiments focussed mostly on monodisperse particle systems whereas dusty plasmas in nature and technology are polydisperse. Thus, a first and important step towards experiments in polydisperse systems are binary mixtures. Recent experiments on binary mixtures under microgravity conditions observed a phase separation of particle species with different radii even for small size disparities. This contradicts several numerical studies of 2D binary mixtures. Therefore, dedicated experiments are required to gain more insight into the physics of polydisperse systems. In this contribution first ground based experiments on two-dimensional binary mixtures are presented. Particular attention is paid to the requirements for the generation of such systems which involve the consideration of the temporal evolution of the particle properties. Furthermore, the structure of these two-component crystals is analyzed and compared to simulations. This work was supported by the Deutsche Forschungsgemeinschaft DFG in the framework of the SFB TR24 Greifswald Kiel, Project A3b.

Decadal variability of surface incident solar radiation over China: Observations, satellite retrievals, and reanalyses

NASA Astrophysics Data System (ADS)

Wang, Kaicun; Ma, Qian; Li, Zhijun; Wang, Jiankai

2015-07-01

Existing studies have shown that observed surface incident solar radiation (Rs) over China may have important inhomogeneity issues. This study provides metadata and reference data to homogenize observed Rs, from which the decadal variability of Rs over China can be accurately derived. From 1958 to 1990, diffuse solar radiation (Rsdif) and direct solar radiation (Rsdir) were measured separately, and Rs was calculated as their sum. The pyranometers used to measure Rsdif had a strong sensitivity drift problem, which introduced a spurious decreasing trend into the observed Rsdif and Rs data, whereas the observed Rsdir did not suffer from this sensitivity drift problem. From 1990 to 1993, instruments and measurement methods were replaced and measuring stations were restructured in China, which introduced an abrupt increase in the observed Rs. Intercomparisons between observation-based and model-based Rs performed in this research show that sunshine duration (SunDu)-derived Rs is of high quality and can be used as reference data to homogenize observed Rs data. The homogenized and adjusted data of observed Rs combines the advantages of observed Rs in quantifying hourly to monthly variability and SunDu-derived Rs in depicting decadal variability and trend. Rs averaged over 105 stations in China decreased at -2.9 W m-2 per decade from 1961 to 1990 and remained stable afterward. This decadal variability is confirmed by the observed Rsdir and diurnal temperature ranges, and can be reproduced by high-quality Earth System Models. However, neither satellite retrievals nor reanalyses can accurately reproduce such decadal variability over China.

WE-D-BRE-02: BEST IN PHYSICS (THERAPY) - Radiogenomic Modeling of Normal Tissue Toxicities in Prostate Cancer Patients Receiving Hypofractionated Radiotherapy

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

Coates, J; Jeyaseelan, K; Ybarra, N

2014-06-15

Purpose: It has been realized that inter-patient radiation sensitivity variability is a multifactorial process involving dosimetric, clinical, and genetic factors. Therefore, we explore a new framework to integrate physical, clinical, and biological data denoted as radiogenomic modeling. In demonstrating the feasibility of this work, we investigate the association of genetic variants (copy number variations [CNVs] and single nucleotide polymorphisms [SNPs]) with radiation induced rectal bleeding (RB) and erectile dysfunction (ED) while taking into account dosimetric and clinical variables in prostate cancer patients treated with curative irradiation. Methods: A cohort of 62 prostate cancer patients who underwent hypofractionated radiotherapy (66 Gymore » in 22 fractions) was retrospectively genotyped for CNV and SNP rs25489 in the xrcc1 DNA repair gene. Dosevolume metrics were extracted from treatment plans of 54 patients who had complete dosimetric profiles. Treatment outcomes were considered to be a Result of functional mapping of radiogenomic input variables according to a logit transformation. Model orders were estimated using resampling by leave-one out cross-validation (LOO-CV). Radiogenomic model performance was evaluated using area under the ROC curve (AUC) and LOO-CV. For continuous univariate dosimetric and clinical variables, Spearmans rank coefficients were calculated and p-values reported accordingly. In the case of binary variables, Chi-squared statistics and contingency table calculations were used. Results: Ten patients were found to have three copies of xrcc1 CNV (RB: χ2=14.6 [p<0.001] and ED: χ2=4.88[p=0.0272]) and twelve had heterozygous rs25489 SNP (RB: χ2=0.278[p=0.599] and ED: χ2=0.112[p=0.732]). LOO-CV identified penile bulb D60 as the only significant QUANTEC predictor (rs=0.312 [p=0.0145]) for ED. Radiogenomic modeling yielded statistically significant, cross-validated NTCP models for RB (rs=0.243[p=0.0443], AUC=0.665) and ED (rs=0.276[p=0.0217], AUC=0.754). Conclusion: The radiogenomic modeling approach presented herein has been shown to identify NTCP models which have increased predictive power. Furthermore, CNVs appears to be useful genetic variants when added to dosimetric NTCP models. This work was partially supported by CIHR grant MOP-114910.« less

Vapor-Liquid Equilibria of Imidazolium Ionic Liquids with Cyano Containing Anions with Water and Ethanol.

PubMed

Khan, Imran; Batista, Marta L S; Carvalho, Pedro J; Santos, Luís M N B F; Gomes, José R B; Coutinho, João A P

2015-08-13

Isobaric vapor-liquid equilibria of 1-butyl-3-methylimidazolium thiocyanate ([C4C1im][SCN]), 1-butyl-3-methylimidazolium dicyanamide ([C4C1im][N(CN)2]), 1-butyl-3-methylimidazolium tricyanomethanide ([C4C1im][C(CN)3]), and 1-ethyl-3-methylimidazolium tetracyanoborate ([C2C1im][B(CN)4]), with water and ethanol were measured over the whole concentration range at 0.1, 0.07, and 0.05 MPa. Activity coefficients were estimated from the boiling temperatures of the binary systems, and the data were used to evaluate the ability of COSMO-RS for describing these molecular systems. Aiming at further understanding the molecular interactions on these systems, molecular dynamics (MD) simulations were performed. On the basis of the interpretation of the radial and spatial distribution functions along with coordination numbers obtained through MD simulations, the effect of the increase of CN-groups in the IL anion in its capability to establish hydrogen bonds with water and ethanol was evaluated. The results obtained suggest that, for both water and ethanol systems, the anion [N(CN)2](-) presents the higher ability to establish favorable interactions due to its charge, and that the ability of the anions to interact with the solvent, decreases with further increasing of the number of cyano groups in the anion. The ordering of the partial charges in the nitrogen atoms from the CN-groups in the anions agrees with the ordering obtained for VLE and activity coefficient data.

VizieR Online Data Catalog: Orbital parameters of 341 new binaries (Murphy+, 2018)

NASA Astrophysics Data System (ADS)

Murphy, S. J.; Moe, M.; Kurtz, D. W.; Bedding, T.; Shibahashi, H.; Boffin, H. M. J.

2018-01-01

Kepler targets with effective temperatures between 6600 and 10000K have been investigated for pulsational phase modulation that can be attributed to binary orbital motion. For each target, we provide a binary status, which also reflects whether or not the target pulsates. For the binary systems, we provide the Kepler Input Catalogue (KIC) number, as well as the binary orbital elements: the period, semi-major axis, eccentricity, longitude of periastron, time of periastron passage, binary mass function and a calculated radial velocity semi-amplitude. (3 data files).

75 FR 20420 - Privacy Act of 1974: System of Records

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-19

... project are covered by this system of records. These individuals are employees of three rail carriers participating in the C\\3\\RS demonstration project. The rail carriers are: Union Pacific Railroad, Canadian Pacific Railroad, and New Jersey Transit. The C\\3\\RS demonstration project is a research effort to improve...

ICT Competence-Based Learning Object Recommendations for Teachers

ERIC Educational Resources Information Center

Sergis, Stylianos; Zervas, Panagiotis; Sampson, Demetrios G.

2014-01-01

Recommender Systems (RS) have been applied in the Technology enhanced Learning (TeL) field for facilitating, among others, Learning Object (LO) selection and retrieval. Most of the existing approaches, however, aim at accommodating the needs of learners and teacher-oriented RS are still an under-investigated field. Moreover, the systems that focus…

Next-Generation RS-25 Engines for the NASA Space Launch System

NASA Technical Reports Server (NTRS)

Ballard, Richard O.

2017-01-01

The utilization of heritage RS-25 engines, also known as the Space Shuttle Main Engine (SSME), has enabled rapid progress in the development and certification of the NASA Space Launch System (SLS) toward operational flight status. The RS-25 brings design maturity and extensive experience gained through 135 missions, 3000+ ground tests, and over 1 million seconds total accumulated hot-fire time. In addition, there were also 16 flight engines and 2 development engines remaining from the Space Shuttle program that could be leveraged to support the first four flights. Beyond these initial SLS flights, NASA must have a renewed supply of RS-25 engines that must reflect program affordability imperatives as well as technical requirements imposed by the SLS Block-1B vehicle (i.e., 111% RPL power level, reduced service life). Recognizing the long lead times needed for the fabrication, assembly and acceptance testing of flight engines, design activities are underway to improve system affordability and eliminate obsolescence concerns. These key objectives are enabled largely by utilizing modern materials and fabrication technologies, but also by innovations in systems engineering and integration (SE&I) practices.

A Web site-based reporting system for monitoring home treatment during oral immunotherapy for food allergy.

PubMed

Nachshon, Liat; Goldberg, Michael R; Elizur, Arnon; Levy, Michael B; Schwartz, Naama; Katz, Yitzhak

2015-06-01

Reactions during the home treatment phase of oral immunotherapy (OIT) are not uncommon. An ongoing accurate reporting of home treatment outcomes is crucial for the safety and success of OIT. Previous reports have shown that as few as 20% of patients are truly compliant with paper-based diaries. To develop a Web site-based electronic reporting system (web-RS) for monitoring home treatment during OIT for food allergy. A web-RS was developed and incorporated a thorough questionnaire querying for pertinent data including the dose(s) consumed, occurrence and details of adverse reactions, treatment(s), and relevant potential exacerbating factors. All patients enrolled in milk, peanut, or egg OIT programs for at least 4 weeks from November 2012 through January 2014 were introduced to web-RS (n = 157). Successful reporting through web-RS was defined by consecutive reporting during the first home treatment phase (24 days) after its introduction. Comparisons were made with a previous group of OIT-treated patients (n = 100) who reported by E-mail. Successful reporting was achieved by 142 of 157 patients (90.44%) in contrast to a 75% success rate with E-mail (P = .0009). The odds for successful reporting using web-RS were 3.1 (95% confidence interval 1.6-6.3) times higher compared with using E-mail. Mild reactions were reported more frequently with web-RS (P = .0032). Patient reports were constantly available in real time for medical staff review. No complaints regarding web-RS feasibility were reported. One risk factor for failure to use web-RS was a patient's prior successful OIT experience without using web-RS (P = .012). A web-RS can be a powerful tool for improving OIT safety by achieving a high level of patient cooperation in reporting home treatment results. Copyright © 2015 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Choosing a Global Positioning System Device for Use in U.S. Army Corps of Engineers Regulatory Districts

DTIC Science & Technology

2017-12-01

Information Systems Center of Expertise (RS/GIS CX) (CEERD-RZR), U.S. Army Engineer Research and Development Center, Cold Regions Research and...GIS Geographic Information Systems GPS Global Positioning System HH Handheld IWR U.S. Army Engineer Institute for Water Resources n/a Not...Applicable NAE U.S. Army New England Regulatory District RS/GIS Remote Sensing/Geographic Information Systems SD Secure Digital SDHC Secure Digital High

An Extensive Census of Hubble Space Telescope Counterparts to Chandra X-Ray Sources in the Globular Cluster 47 Tucanae. I. Astrometry and Photometry

NASA Astrophysics Data System (ADS)

Edmonds, Peter D.; Gilliland, Ronald L.; Heinke, Craig O.; Grindlay, Jonathan E.

2003-10-01

We report in this study of 47 Tucanae the largest number of optical identifications of X-ray sources yet obtained in a single globular cluster. Using deep Chandra ACIS-I imaging and extensive Hubble Space Telescope studies with Wide Field Planetary Camera 2 (WFPC2; including a 120 orbit program giving superb V and I images), we have detected optical counterparts to at least 22 cataclysmic variables (CVs) and 29 chromospherically active binaries (BY Dra and RS CVn systems) in 47 Tuc. These identifications are all based on tight astrometric matches between X-ray sources and objects with unusual (non-main-sequence [non-MS]) optical colors and/or optical variability. Several other CVs and active binaries have likely been found, but these have marginal significance because of larger offsets between the X-ray and optical positions, or colors and variability that are not statistically convincing. These less secure optical identifications are not subsequently discussed in detail. In the U versus U-V color-magnitude diagram (CMD), where the U band corresponds to either F336W or F300W, the CVs all show evidence for blue colors compared with the MS, but most of them fall close to the main sequence in the V versus V-I CMD, showing that the secondary stars dominate the optical light. The X-ray-detected active binaries have magnitude offsets above the MS (in both the U versus U-V or V versus V-I CMDs) that are indistinguishable from those of the much larger sample of optical variables (eclipsing and contact binaries and BY Dra variables) detected in the recent WFPC2 studies of Albrow et al. We also present the results of a new, deeper search for optical companions to millisecond pulsars (MSPs). One possible optical companion to an MSP (47 Tuc T) was found, adding to the two optical companions already known. Finally, we study several blue stars with periodic variability from Albrow et al. that show little or no evidence for X-ray emission. The optical colors of these objects differ from those of 47 Tuc (and field) CVs. An accompanying paper will present time series results for these optical identifications and will discuss X-ray-to-optical flux ratios, spatial distributions, and an overall interpretation of the results. Based on observations with the NASA/ESA Hubble Space Telescope obtained at STScI, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

The Development of Combined Raman Spectroscopy-Optical Coherence Tomography and Application for Skin Cancer Diagnosis

NASA Astrophysics Data System (ADS)

Patil, Chetan

2009-11-01

Optical spectroscopy and imaging have shown promise for performing rapid, non-invasive disease detection and diagnosis in vivo. Independently, Raman Spectroscopy (RS) has demonstrated the ability to perform diagnosis of epithelial cancers such the cervix with excellent overall classification accuracy due to the inherent biochemical specificity of the technique, however relating features of tissue morphology with techniques such as Raman mapping is clinically impractical due to the weak nature of the scattering phenomena resulting in prohibitively long acquisition times. Optical Coherence Tomography (OCT), on the other hand, has demonstrated the ability to perform real-time, high-resolution, cross-sectional imaging of the microstructural characteristics of disease, but typically lacks molecularly specific information that can assist in classifying pathological lesions. We present the development of a combined Raman Spectroscopy-OCT (RS-OCT) instrument capable of compensating for the limitations of each technique individually and performing both biochemical and microstructural evaluation of tissues. We will include the design and development of benchtop RS-OCT implementations based on independent 785 nm Raman and 1310 nm time-domain OCT system backbones, as well as with a 785nm Raman / 850nm spectral-domain OCT setup employing an integrated detection arm. These systems motivated the ultimate design of a clinical RS-OCT system for application in dermatology. In order to aid in the development of our Raman spectral processing and classification methods, we conducted a simultaneous pilot study in which RS alone was used to measure basal and squamous cell carcinomas. We will present the initial results from our clinical experiences with the combined RS-OCT device, and include a discussion of spectral classification and the ultimate potential of combined RS-OCT for skin cancer diagnosis.

Resistance to pentamidine is mediated by AdeAB, regulated by AdeRS, and influenced by growth conditions in Acinetobacter baumannii ATCC 17978.

PubMed

Adams, Felise G; Stroeher, Uwe H; Hassan, Karl A; Marri, Shashikanth; Brown, Melissa H

2018-01-01

In recent years, effective treatment of infections caused by Acinetobacter baumannii has become challenging due to the ability of the bacterium to acquire or up-regulate antimicrobial resistance determinants. Two component signal transduction systems are known to regulate expression of virulence factors including multidrug efflux pumps. Here, we investigated the role of the AdeRS two component signal transduction system in regulating the AdeAB efflux system, determined whether AdeA and/or AdeB can individually confer antimicrobial resistance, and explored the interplay between pentamidine resistance and growth conditions in A. baumannii ATCC 17978. Results identified that deletion of adeRS affected resistance towards chlorhexidine and 4',6-diamidino-2-phenylindole dihydrochloride, two previously defined AdeABC substrates, and also identified an 8-fold decrease in resistance to pentamidine. Examination of ΔadeA, ΔadeB and ΔadeAB cells augmented results seen for ΔadeRS and identified a set of dicationic AdeAB substrates. RNA-sequencing of ΔadeRS revealed transcription of 290 genes were ≥2-fold altered compared to the wildtype. Pentamidine shock significantly increased adeA expression in the wildtype, but decreased it in ΔadeRS, implying that AdeRS activates adeAB transcription in ATCC 17978. Investigation under multiple growth conditions, including the use of Biolog phenotypic microarrays, revealed resistance to pentamidine in ATCC 17978 and mutants could be altered by bioavailability of iron or utilization of different carbon sources. In conclusion, the results of this study provide evidence that AdeAB in ATCC 17978 can confer intrinsic resistance to a subset of dicationic compounds and in particular, resistance to pentamidine can be significantly altered depending on the growth conditions.

Performance Enhancement of Radial Distributed System with Distributed Generators by Reconfiguration Using Binary Firefly Algorithm

NASA Astrophysics Data System (ADS)

Rajalakshmi, N.; Padma Subramanian, D.; Thamizhavel, K.

2015-03-01

The extent of real power loss and voltage deviation associated with overloaded feeders in radial distribution system can be reduced by reconfiguration. Reconfiguration is normally achieved by changing the open/closed state of tie/sectionalizing switches. Finding optimal switch combination is a complicated problem as there are many switching combinations possible in a distribution system. Hence optimization techniques are finding greater importance in reducing the complexity of reconfiguration problem. This paper presents the application of firefly algorithm (FA) for optimal reconfiguration of radial distribution system with distributed generators (DG). The algorithm is tested on IEEE 33 bus system installed with DGs and the results are compared with binary genetic algorithm. It is found that binary FA is more effective than binary genetic algorithm in achieving real power loss reduction and improving voltage profile and hence enhancing the performance of radial distribution system. Results are found to be optimum when DGs are added to the test system, which proved the impact of DGs on distribution system.

Genetic variation in the endocannabinoid system and response to Cognitive Behavior Therapy for child anxiety disorders.

PubMed

Lester, Kathryn J; Coleman, Jonathan R I; Roberts, Susanna; Keers, Robert; Breen, Gerome; Bögels, Susan; Creswell, Cathy; Hudson, Jennifer L; McKinnon, Anna; Nauta, Maaike; Rapee, Ronald M; Schneider, Silvia; Silverman, Wendy K; Thastum, Mikael; Waite, Polly; Wergeland, Gro Janne H; Eley, Thalia C

2017-03-01

Extinction learning is an important mechanism in the successful psychological treatment of anxiety. Individual differences in response and relapse following Cognitive Behavior Therapy may in part be explained by variability in the ease with which fears are extinguished or the vulnerability of these fears to re-emerge. Given the role of the endocannabinoid system in fear extinction, this study investigates whether genetic variation in the endocannabinoid system explains individual differences in response to CBT. Children (N = 1,309) with a primary anxiety disorder diagnosis were recruited. We investigated the relationship between variation in the CNR1, CNR2, and FAAH genes and change in primary anxiety disorder severity between pre- and post-treatment and during the follow-up period in the full sample and a subset with fear-based anxiety disorder diagnoses. Change in symptom severity during active treatment was nominally associated (P < 0.05) with two SNPs. During the follow-up period, five SNPs were nominally associated with a poorer treatment response (rs806365 [CNR1]; rs2501431 [CNR2]; rs2070956 [CNR2]; rs7769940 [CNR1]; rs2209172 [FAAH]) and one with a more favorable response (rs6928813 [CNR1]). Within the fear-based subset, the effect of rs806365 survived multiple testing corrections (P < 0.0016). We found very limited evidence for an association between variants in endocannabinoid system genes and treatment response once multiple testing corrections were applied. Larger, more homogenous cohorts are needed to allow the identification of variants of small but statistically significant effect and to estimate effect sizes for these variants with greater precision in order to determine their potential clinical utility. © 2016 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc. © 2016 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc.

Trace-shortened Reed-Solomon codes

NASA Technical Reports Server (NTRS)

Mceliece, R. J.; Solomon, G.

1994-01-01

Reed-Solomon (RS) codes have been part of standard NASA telecommunications systems for many years. RS codes are character-oriented error-correcting codes, and their principal use in space applications has been as outer codes in concatenated coding systems. However, for a given character size, say m bits, RS codes are limited to a length of, at most, 2(exp m). It is known in theory that longer character-oriented codes would be superior to RS codes in concatenation applications, but until recently no practical class of 'long' character-oriented codes had been discovered. In 1992, however, Solomon discovered an extensive class of such codes, which are now called trace-shortened Reed-Solomon (TSRS) codes. In this article, we will continue the study of TSRS codes. Our main result is a formula for the dimension of any TSRS code, as a function of its error-correcting power. Using this formula, we will give several examples of TSRS codes, some of which look very promising as candidate outer codes in high-performance coded telecommunications systems.

Full Ionisation In Binary-Binary Encounters With Small Positive Energies

NASA Astrophysics Data System (ADS)

Sweatman, W. L.

2006-08-01

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

Extrasolar binary planets. I. Formation by tidal capture during planet-planet scattering

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

Ochiai, H.; Nagasawa, M.; Ida, S., E-mail: nagasawa.m.ad@m.titech.ac.jp

2014-08-01

We have investigated (1) the formation of gravitationally bounded pairs of gas-giant planets (which we call 'binary planets') from capturing each other through planet-planet dynamical tide during their close encounters and (2) the subsequent long-term orbital evolution due to planet-planet and planet-star quasi-static tides. For the initial evolution in phase 1, we carried out N-body simulations of the systems consisting of three Jupiter-mass planets taking into account the dynamical tide. The formation rate of the binary planets is as much as 10% of the systems that undergo orbital crossing, and this fraction is almost independent of the initial stellarcentric semimajormore » axes of the planets, while ejection and merging rates sensitively depend on the semimajor axes. As a result of circularization by the planet-planet dynamical tide, typical binary separations are a few times the sum of the physical radii of the planets. After the orbital circularization, the evolution of the binary system is governed by long-term quasi-static tide. We analytically calculated the quasi-static tidal evolution in phase 2. The binary planets first enter the spin-orbit synchronous state by the planet-planet tide. The planet-star tide removes angular momentum of the binary motion, eventually resulting in a collision between the planets. However, we found that the binary planets survive the tidal decay for the main-sequence lifetime of solar-type stars (∼10 Gyr), if the binary planets are beyond ∼0.3 AU from the central stars. These results suggest that the binary planets can be detected by transit observations at ≳ 0.3 AU.« less

Dynamical Evolution and Momentum Transfer for Binary Asteroid Systems

NASA Astrophysics Data System (ADS)

Bellerose, Julie

Over the past decade, robotic missions have been sent to small bodies, providing a basic understanding of their environment. Some of these small systems are found to be in pairs, orbiting each other, which are thought to represent about 16% of the near-Earth asteroid population. It is fair to assume that a mission will target a binary asteroid system in the near future as they can enable scientific insight into both the geology and dynamics of asteroids. In previous work, the dynamical evolution of binary systems was investigated for an ellipsoidsphere model. From the dynamics of two celestial bodies, equilibrium configurations and their stability were analyzed. For a given value of angular momentum, it was shown that there are in general two relative equilibrium configurations which are opposite in stability. When perturbations are introduced, we found that the equilibrium states are the minimum energy points of nearby periodic families. General dynamics from unstable to stable configurations were investigated for binaries in close proximity. Accounting for the dynamics of binaries, the dynamics of particles in this gravitational field were also studied. The location of the analogue Lagrangian points and energy associated with them were characterized. The L1 region is a key element for transfers between the bodies. It was shown that L1 can be situated between or inside the bodies depending on the free parameters of the system modifying the transfer possibilities since L1 has a hyperbolic manifold associated with it. In the current work, we look at the L1 region for binary system where the bodies are in relative equilibrium, close to each other. We find that L1 transits from outside to inside the ellipsoid when the mass ratio is larger than 0.6. For binary systems in close proximity with L1 being inside the ellipsoidal body, simulations show that particles on the surface tend to move away from the ellipsoid, toward the spherical primary. We can relate this to the Roche limit of binaries which affect the distribution of mass between the bodies. Other parameters such as the spin rate of a larger spherical primary may also influence particle distribution. Hence, we can map and characterize the mass distribution and momentum exchange that may occur within a closely formed binary systems.

Estimating Mass Parameters of Doubly Synchronous Binary Asteroids

NASA Astrophysics Data System (ADS)

Davis, Alex; Scheeres, Daniel J.

2017-10-01

The non-spherical mass distributions of binary asteroid systems lead to coupled mutual gravitational forces and torques. Observations of the coupled attitude and orbital dynamics can be leveraged to provide information about the mass parameters of the binary system. The full 3-dimensional motion has 9 degrees of freedom, and coupled dynamics require the use of numerical investigation only. In the current study we simplify the system to a planar ellipsoid-ellipsoid binary system in a doubly synchronous orbit. Three modes are identified for the system, which has 4 degrees of freedom, with one degree of freedom corresponding to an ignorable coordinate. The three modes correspond to the three major librational modes of the system when it is in a doubly synchronous orbit. The linearized periods of each mode are a function of the mass parameters of the two asteroids, enabling measurement of these parameters based on observations of the librational motion. Here we implement estimation techniques to evaluate the capabilities of this mass measurement method. We apply this methodology to the Trojan binary asteroid system 617 Patroclus and Menoetius (1906 VY), the final flyby target of the recently announced LUCY Discovery mission. This system is of interest because a stellar occultation campaign of the Patroclus and Menoetius system has suggested that the asteroids are similarly sized oblate ellipsoids moving in a doubly-synchronous orbit, making the system an ideal test for this investigation. A number of missed observations during the campaign also suggested the possibility of a crater on the southern limb of Menoetius, the presence of which could be evaluated by our mass estimation method. This presentation will review the methodology and potential accuracy of our approach in addition to evaluating how the dynamical coupling can be used to help understand light curve and stellar occultation observations for librating binary systems.

Spectroscopic observations of V443 Herculis - A symbiotic binary with a low mass white dwarf

NASA Technical Reports Server (NTRS)

Dobrzycka, Danuta; Kenyon, Scott J.; Mikolajewska, Joanna

1993-01-01

We present an analysis of new and existing photometric and spectroscopic observations of the symbiotic binary V443 Herculis. This binary system consists of a normal M5 giant and a hot compact star. These two objects have comparable luminosities: about 1500 solar for the M5 giant and about 1000 solar for the compact star. We identify three nebular regions in this binary: a small, highly ionized volume surrounding the hot component, a modestly ionized shell close to the red giant photosphere, and a less dense region of intermediate ionization encompassing both binary components. The system parameters for V443 Her suggest the hot component currently declines from a symbiotic nova eruption.

Study of binary asteroids with three space missions

NASA Astrophysics Data System (ADS)

Kovalenko, Irina; Doressoundiram, Alain; Hestroffer, Daniel

Binary and multiple asteroids are common in the Solar system and encountered in various places going from Near-Earth region, to the main-belt, Trojans and Centaurs, and beyond Neptune. Their study can provide insight on the Solar System formation and its subsequent dynamical evolution. Binaries are also objects of high interest because they provide fundamental physical parameters such as mass and density, and hence clues on the early Solar System, or other processes that are affecting asteroid over time. We will present our current project on analysis of such systems based on three space missions. The first one is the Herschel space observatory (ESA), the largest infrared telescope ever launched. Thirty Centaurs and trans-Neptunian binaries were observed by Herschel and the measurement allowed to define size, albedo and thermal properties [1]. The second one is the satellite Gaia (ESA). This mission is designed to chart a three-dimensional map of the Galaxy. Gaia will provide positional measurements of Solar System Objects - including asteroid binaries - with unprecedented accuracy [2]. And the third one is the proposed mission AIDA, which would study the effects of crashing a spacecraft into an asteroid [3]. The objectives are to demonstrate the ability to modify the trajectory of an asteroid, to precisely measure its trajectory change, and to characterize its physical properties. The target of this mission is a binary system: (65803) Didymos. This encompasses orbital characterisations for both astrometric and resolved binaries, as well as unbound orbit, study of astrometric binaries, derivation of densities, and general statistical analysis of physical and orbital properties of trans-Neptunian and other asteroid binaries. Acknowledgements : work supported by Labex ESEP (ANR N° 2011-LABX-030) [1] Müller T., Lellouch E., Stansberry J. et al. 2009. TNOs are Cool: A Survey of the Transneptunian Region. EM&P 105, 209-219. [2] Mignard F., Cellino A., Muinonen K. et al. 2007. The Gaia Mission: Expected Applications to Asteroid Science. EM&P 1001, 97-125. [3] Galvez A., Carnelli I. et al. 2013. AIDA: The Asteroid Impact & Deflection Assessment Mission. EPSC 2013 - 1043.

Orbital motion in pre-main sequence binaries

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

Schaefer, G. H.; Prato, L.; Simon, M.

2014-06-01

We present results from our ongoing program to map the visual orbits of pre-main sequence (PMS) binaries in the Taurus star forming region using adaptive optics imaging at the Keck Observatory. We combine our results with measurements reported in the literature to analyze the orbital motion for each binary. We present preliminary orbits for DF Tau, T Tau S, ZZ Tau, and the Pleiades binary HBC 351. Seven additional binaries show curvature in their relative motion. Currently, we can place lower limits on the orbital periods for these systems; full solutions will be possible with more orbital coverage. Five othermore » binaries show motion that is indistinguishable from linear motion. We suspect that these systems are bound and might show curvature with additional measurements in the future. The observations reported herein lay critical groundwork toward the goal of measuring precise masses for low-mass PMS stars.« less

Periodic Emission from the Gamma-Ray Binary 1FGL J1018.6-5856

DOE PAGES

Ackermann, M.

2012-01-12

Gamma-ray binaries are stellar systems containing a neutron star or black hole with gamma-ray emission produced by an interaction between the components. These systems are rare, even though binary evolution models predict dozens in our Galaxy. A search for gamma-ray binaries with the Fermi Large Area Telescope (LAT) shows that 1FGL J1018.6-5856 exhibits intensity and spectral modulation with a 16.6 day period. We identified a variable X-ray counterpart, which shows a sharp maximum coinciding with maximum gamma-ray emission, as well as an O6V((f)) star optical counterpart and a radio counterpart that is also apparently modulated on the orbital period. 1FGLmore » J1018.6-5856 is thus a gamma-ray binary, and its detection suggests the presence of other fainter binaries in the Galaxy.« less

"Single nucleotide polymorphisms of the OPG/RANKL system genes in primary hyperparathyroidism and their relationship with bone mineral density".

PubMed

Piedra, María; García-Unzueta, María T; Berja, Ana; Paule, Blanca; Lavín, Bernardo A; Valero, Carmen; Riancho, José A; Amado, José A

2011-12-20

Primary hyperparathyroidism (PHPT) affects mainly cortical bone. It is thought that parathyroid hormone (PTH) indirectly regulates the activity of osteoclasts by means of the osteoprotegerin/ligand of the receptor activator of nuclear factor-κβ (OPG/RANKL) system. Several studies have confirmed that OPG (osteoprotegerin) and RANKL (ligand of the receptor activator of nuclear factor-κβ) loci are determinants of bone mineral density (BMD) in the general population. The aim of this study is to analyze the relationship between fractures and BMD and the rs3102735 (163 A/G), rs3134070 (245 T/G) and rs2073618 (1181 G/C) SNPs of the OPG and the rs2277438 SNP of the RANKL, in patients with sporadic PHPT. We enrolled 298 Caucasian patients with PHPT and 328 healthy volunteers in a cross-sectional study. We analyzed anthropometric data, history of fractures or renal lithiasis, biochemical determinants including markers for bone remodelling, BMD measurements in the lumbar spine, total hip, femoral neck and distal radius, and genotyping for the SNPs to be studied. Regarding the age of diagnosis, BMI, menopause status, frequency of fractures or renal lithiasis, we found no differences between genotypes in any of the SNPs studied in the PHPT group. Significant lower BMD in the distal radius with similar PTH levels was found in the minor allele homozygotes (GG) compared to heterozygotes and major allele homozygotes in both OPG rs3102735 (163 A/G) and OPG rs3134070 (245 T/G) SNPs in those with PHPT compared to control subjects. We found no differences between genotypes of the OPG rs2073618 (1181 G/C) SNP with regard to BMD in the PHPT subjects. In the evaluation of rs2277438 SNP of the RANKL in PHPT patients, we found a non significant trend towards lower BMD in the 1/3 distal radius and at total hip in the minor allele homocygotes (GG) genotype group versus heterocygotes and major allele homocygotes (AA). Our study provides the first evaluation of the relationship between SNPs of the OPG/RANK system and sporadic PHPT. Subjects with PHPT and minor homocygote genotype (GG) for the OPG rs3102735 (163 A/G) and OPG rs3134070 (245 T/G) SNPs have lower BMD in the distal radius, and this association does not appear to be mediated by differences in PTH serum levels.

The formation of planetary systems during the evolution of close binary stars

NASA Astrophysics Data System (ADS)

Tutukov, A. V.

1991-08-01

Modern scenarios of the formation of planetary systems around single stars and products of merging close binaries are described. The frequencies of the realization of different scenarios in the Galaxy are estimated. It is concluded that the modern theory of the early stages of the evolution of single stars and the theory of the evolution of close binaries offer several possible versions for the origin of planetary systems, while the scenario dating back to Kant and Laplace remains the likeliest.

Sizing up the population of gamma-ray binaries

NASA Astrophysics Data System (ADS)

Dubus, Guillaume; Guillard, Nicolas; Petrucci, Pierre-Olivier; Martin, Pierrick

2017-12-01

Context. Gamma-ray binaries are thought to be composed of a young pulsar in orbit around a massive O or Be star with their gamma-ray emission powered by pulsar spin-down. The number of such systems in our Galaxy is not known. Aims: We aim to estimate the total number of gamma-ray binaries in our Galaxy and to evaluate the prospects for new detections in the GeV and TeV energy range, taking into account that their gamma-ray emission is modulated on the orbital period. Methods: We modelled the population of gamma-ray binaries and evaluated the fraction of detected systems in surveys with the Fermi-LAT (GeV), H.E.S.S., HAWC and CTA (TeV) using observation-based and synthetic template light curves. Results: The detected fraction depends more on the orbit-average flux than on the light-curve shape. Our best estimate for the number of gamma-ray binaries is 101-52+89 systems. A handful of discoveries are expected by pursuing the Fermi-LAT survey. Discoveries in TeV surveys are less likely. However, this depends on the relative amounts of power emitted in GeV and TeV domains. There could be as many as ≈ 200 HESS J0632+057-like systems with a high ratio of TeV to GeV emission compared to other gamma-ray binaries. Statistics allow for as many as three discoveries in five years of HAWC observations and five discoveries in the first two years of the CTA Galactic Plane survey. Conclusions: We favour continued Fermi-LAT observations over ground-based TeV surveys to find new gamma-ray binaries. Gamma-ray observations are most sensitive to short orbital period systems with a high spin-down pulsar power. Radio pulsar surveys (SKA) are likely to be more efficient in detecting long orbital period systems, providing a complementary probe into the gamma-ray binary population.

Autonomous agricultural remote sensing systems with high spatial and temporal resolutions

NASA Astrophysics Data System (ADS)

Xiang, Haitao

In this research, two novel agricultural remote sensing (RS) systems, a Stand-alone Infield Crop Monitor RS System (SICMRS) and an autonomous Unmanned Aerial Vehicles (UAV) based RS system have been studied. A high-resolution digital color and multi-spectral camera was used as the image sensor for the SICMRS system. An artificially intelligent (AI) controller based on artificial neural network (ANN) and an adaptive neuro-fuzzy inference system (ANFIS) was developed. Morrow Plots corn field RS images in the 2004 and 2006 growing seasons were collected by the SICMRS system. The field site contained 8 subplots (9.14 m x 9.14 m) that were planted with corn and three different fertilizer treatments were used among those subplots. The raw RS images were geometrically corrected, resampled to 10cm resolution, removed soil background and calibrated to real reflectance. The RS images from two growing seasons were studied and 10 different vegetation indices were derived from each day's image. The result from the image processing demonstrated that the vegetation indices have temporal effects. To achieve high quality RS data, one has to utilize the right indices and capture the images at the right time in the growing season. Maximum variations among the image data set are within the V6-V10 stages, which indicated that these stages are the best period to identify the spatial variability caused by the nutrient stress in the corn field. The derived vegetation indices were also used to build yield prediction models via the linear regression method. At that point, all of the yield prediction models were evaluated by comparing the R2-value and the best index model from each day's image was picked based on the highest R 2-value. It was shown that the green normalized difference vegetation (GNDVI) based model is more sensitive to yield prediction than other indices-based models. During the VT-R4 stages, the GNDVI based models were able to explain more than 95% potential corn yield consistently for both seasons. The VT-R4 stages are the best period of time to estimate the corn yield. The SICMS system is only suitable for the RS research at a fixed location. In order to provide more flexibility of the RS image collection, a novel UAV based system has been studied. The UAV based agricultural RS system used a light helicopter platform equipped with a multi-spectral camera. The UAV control system consisted of an on-board and a ground station subsystem. For the on-board subsystem, an Extended Kalman Filter (EKF) based UAV navigation system was designed and implemented. The navigation system, using low cost inertial sensors, magnetometer, GPS and a single board computer, was capable of providing continuous estimates of UAV position and attitude at 50 Hz using sensor fusion techniques. The ground station subsystem was designed to be an interface between a human operator and the UAV to implement mission planning, flight command activation, and real-time flight monitoring. The navigation system is controlled by the ground station, and able to navigate the UAV in the air to reach the predefined waypoints and trigger the multi-spectral camera. By so doing, the aerial images at each point could be captured automatically. The developed UAV RS system can provide a maximum flexibility in crop field RS image collection. It is essential to perform the geometric correction and the geocoding before an aerial image can be used for precision farming. An automatic (no Ground Control Point (GCP) needed) UAV image georeferencing algorithm was developed. This algorithm can do the automatic image correction and georeferencing based on the real-time navigation data and a camera lens distortion model. The accuracy of the georeferencing algorithm was better than 90 cm according to a series test. The accuracy that has been achieved indicates that, not only is the position solution good, but the attitude error is extremely small. The waypoints planning for UAV flight was investigated. It suggested that a 16.5% forward overlap and a 15% lateral overlap were required to avoiding missing desired mapping area when the UAV flies above 45 m high with 4.5 mm lens. A whole field mosaic image can be generated according to the individual image georeferencing information. A 0.569 m mosaic error has been achieved and this accuracy is sufficient for many of the intended precision agricultural applications. With careful interpretation, the UAV images are an excellent source of high spatial and temporal resolution data for precision agricultural applications. (Abstract shortened by UMI.)

[Genetic predictors of myocardial infarction in subjects of young age].

PubMed

Shesternia, P A; Nikulina, S Iu; Shul'man, V A; Martynova, E A; Demkina, A I; Orlov, P S; Maksimov, V N; Voevoda, M I

2013-01-01

to investigate associations of single nucleotide polymorphisms (SNP) rs499818 (6p24.1), rs619203 of ROS1 gene (6q22), rs10757278 rs1333049 (9p21.3), rs2549513 (16q23.1), rs4804611 of ZNF627 gene (19p13.2) with myocardial infarction in subjects of young age. The group of patients with MI (n=99) aged less than 45 years and the control group (n=111) did not differ significantly by sex (=0,617), age (=0.291), arterial hypertension (=0.766), diabetes mellitus (=0.395), hypercholestolemia (=0.696), excessive body mass and obesity (=0.361), abdominal obesity (=0.831) and history of smoking (=0.400). There was significant difference between groups by burdened heredity (<0.001). Genomic DNA was obtained from venous blood by phenol-chloroform extraction. Genetic testing was performed by real time polymerase chain reaction using 7900HT Fast Real-Time PCR System according to manufacturers protocol. We found significant association between rs1333049 and rs10757278 and myocardial infarction (MI). Odds ratio (OR) of development of MI in carriers of risk allele rs1333049 was 2.4 (95% confidence interval [CI] 1.24 to 4.65), in carriers of G rs10757278 allele - 2.00 (95%CI 1.05 to 3.80). Association of risk alleles rs 1333049 and G rs10757278 with MI remained significant after adjustment for burdened family history (OR 4.25, 95%CI 1.39 to 12.99, and OR 3.04, 95%CI 1.09 to 8.52, respectively). Presence in the genotype of both risk alleles rs1333049 and G rs10757278 was associated with OR of MI development 2.40 (95%CI 1.20 to 4.82) which was not different from that associated with carriage of allele rs1333049 only. Possibly in our population both SNPs belong to one linkage block and correspondingly it is sufficient to genotype one SNP. No significant associations with MI were found for variants rs4804611, rs2549513, rs499818, rs619203. SNPs rs1333049 and rs10757278 of 9p21.3 locus are predictors of MI in young individuals not dependent on both traditional risk factors and presence of burdened family history.

Constraining Accreting Binary Populations in Normal Galaxies

NASA Astrophysics Data System (ADS)

Lehmer, Bret; Hornschemeier, A.; Basu-Zych, A.; Fragos, T.; Jenkins, L.; Kalogera, V.; Ptak, A.; Tzanavaris, P.; Zezas, A.

2011-01-01

X-ray emission from accreting binary systems (X-ray binaries) uniquely probe the binary phase of stellar evolution and the formation of compact objects such as neutron stars and black holes. A detailed understanding of X-ray binary systems is needed to provide physical insight into the formation and evolution of the stars involved, as well as the demographics of interesting binary remnants, such as millisecond pulsars and gravitational wave sources. Our program makes wide use of Chandra observations and complementary multiwavelength data sets (through, e.g., the Spitzer Infrared Nearby Galaxies Survey [SINGS] and the Great Observatories Origins Deep Survey [GOODS]), as well as super-computing facilities, to provide: (1) improved calibrations for correlations between X-ray binary emission and physical properties (e.g., star-formation rate and stellar mass) for galaxies in the local Universe; (2) new physical constraints on accreting binary processes (e.g., common-envelope phase and mass transfer) through the fitting of X-ray binary synthesis models to observed local galaxy X-ray binary luminosity functions; (3) observational and model constraints on the X-ray evolution of normal galaxies over the last 90% of cosmic history (since z 4) from the Chandra Deep Field surveys and accreting binary synthesis models; and (4) predictions for deeper observations from forthcoming generations of X-ray telesopes (e.g., IXO, WFXT, and Gen-X) to provide a science driver for these missions. In this talk, we highlight the details of our program and discuss recent results.

The evolution of photoevaporating viscous discs in binaries

NASA Astrophysics Data System (ADS)

Rosotti, Giovanni P.; Clarke, Cathie J.

2018-02-01

A large fraction of stars are in binary systems, yet the evolution of protoplanetary discs in binaries has been little explored from the theoretical side. In this paper, we investigate the evolution of the discs surrounding the primary and secondary components of binary systems on the assumption that this is driven by photoevaporation induced by X-rays from the respective star. We show how for close enough separations (20-30 au for average X-ray luminosities) the tidal torque of the companion changes the qualitative behaviour of disc dispersal from inside out to outside in. Fewer transition discs created by photoevaporation are thus expected in binaries. We also demonstrate that in close binaries the reduction in viscous time leads to accelerated disc clearing around both components, consistent with unresolved observations. When looking at the differential disc evolution around the two components, in close binaries discs around the secondary clear first due to the shorter viscous time-scale associated with the smaller outer radius. In wide binaries instead the difference in photoevaporation rate makes the secondaries longer lived, though this is somewhat dependent on the assumed scaling of viscosity with stellar mass. We find that our models are broadly compatible with the growing sample of resolved observations of discs in binaries. We also predict that binaries have higher accretion rates than single stars for the same disc mass. Thus, binaries probably contribute to the observed scatter in the relationship between disc mass and accretion rate in young stars.

Habitability in Binary Systems: The Role of UV Reduction and Magnetic Protection

NASA Astrophysics Data System (ADS)

Clark, Joni; Mason, P. A.; Zuluaga, J. I.; Cuartas, P. A.; Bustamonte, S.

2013-06-01

The number of planets found in binary systems is growing rapidly and the discovery of many more planets in binary systems appears inevitable. We use the newly refined and more restrictive, single star habitable zone (HZ) models of Kopparapu et al. (2013) and include planetary magnetic protection calculations in order to investigate binary star habitability. Here we present results on circumstellar or S-type planets, which are planets orbiting a single star member of a binary. P-type planets, on the other hand, orbit the center of mass of the binary. Stable planetary orbits exist in HZs for both types of binaries as long as the semi-major axis of the planet is either greater than (P-type) or less than (S-type) a few times the semi-major axis of the binary. We define two types of S-type binaries for this investigation. The SA-type is a circumstellar planet orbiting the binary’s primary star. In this case, the limits of habitability are dominated by the primary being only slightly affected by the presence of the lower mass companion. Thus, the SA-type planets have habitability characteristics, including magnetic protection, similar to single stars of the same type. The SB-type is a circumstellar planet orbiting the secondary star in a wide binary. An SB-type planet needs to orbit slightly outside the secondary’s single star HZ and remain within the primary’s single star HZ at all times. We explore the parameter space for which this is possible. We have found that planets lying in the combined HZ of SB binaries can be magnetically protected against the effects of stellar winds from both primary and secondary stars in a limited number of cases. We conclude that habitable conditions exist for a subset of SA-type, and a smaller subset of SB-type binaries. However, circumbinary planets (P-types) provide the most intriguing possibilities for the existence of complex life due to the effect of synchronization of binaries with periods in the 20-30 day range which allows for planets with significant magnetic protection.

Absolute parameters and chemical composition of the binary star OU Gem

NASA Astrophysics Data System (ADS)

Glazunova, L. V.; Mishenina, T. V.; Soubiran, C.; Kovtyukh, V. V.

2014-10-01

The absolute parameters and chemical composition of the BY Dra-type spectroscopic binary OU Gem (HD 45088) were determined on the basis of 10 high-resolution spectra. A new orbital solution of the binary system was determined, the binary ephemerides were specified, and the main physical and atmospheric parameters of the binary components were obtained. The chemical composition of both components was estimated for the first time for the stars of such type.

Orbital synchronization capture of two binaries emitting gravitational waves

NASA Astrophysics Data System (ADS)

Seto, Naoki

2018-03-01

We study the possibility of orbital synchronization capture for a hierarchical quadrupole stellar system composed by two binaries emitting gravitational waves. Based on a simple model including the mass transfer for white dwarf binaries, we find that the capture might be realized for inter-binary distances less than their gravitational wavelength. We also discuss related intriguing phenomena such as a parasitic relation between the coupled white dwarf binaries and significant reductions of gravitational and electromagnetic radiations.

Biometric feature embedding using robust steganography technique

NASA Astrophysics Data System (ADS)

Rashid, Rasber D.; Sellahewa, Harin; Jassim, Sabah A.

2013-05-01

This paper is concerned with robust steganographic techniques to hide and communicate biometric data in mobile media objects like images, over open networks. More specifically, the aim is to embed binarised features extracted using discrete wavelet transforms and local binary patterns of face images as a secret message in an image. The need for such techniques can arise in law enforcement, forensics, counter terrorism, internet/mobile banking and border control. What differentiates this problem from normal information hiding techniques is the added requirement that there should be minimal effect on face recognition accuracy. We propose an LSB-Witness embedding technique in which the secret message is already present in the LSB plane but instead of changing the cover image LSB values, the second LSB plane will be changed to stand as a witness/informer to the receiver during message recovery. Although this approach may affect the stego quality, it is eliminating the weakness of traditional LSB schemes that is exploited by steganalysis techniques for LSB, such as PoV and RS steganalysis, to detect the existence of secrete message. Experimental results show that the proposed method is robust against PoV and RS attacks compared to other variants of LSB. We also discussed variants of this approach and determine capacity requirements for embedding face biometric feature vectors while maintain accuracy of face recognition.

Radio wavelength observations of magnetic fields on active dwarf M, RS CVn and magnetic stars

NASA Technical Reports Server (NTRS)

Lang, Kenneth R.

1986-01-01

The dwarf M stars, YZ Canis Minoris and AD Leonis, exhibit narrow-band, slowly varying (hours) microwave emission that cannot be explained by conventional thermal radiation mechanisms. The dwarf M stars, AD Leonis and Wolf 424, emit rapid spikes whose high brightness temperatures similarly require a nonthermal radiation process. They are attributed to coherent mechanisms such as an electron-cyclotron maser or coherent plasma radiation. If the electron-cyclotron maser emits at the second or third harmonic gyrofrequency, the coronal magnetic field strength equals 250 G or 167 G, and constraints on the plasma frequency imply an electron density of 6 x 10 to the 9th/cu cm. Radio spikes from AD Leonis and Wolf 424 have rise times less than or equal to 5 ms, indicating a linear size of less than or equal to 1.5 x 10 to the 8th cm, or less than 0.005 of the stellar radius. Although Ap magnetic stars have strong dipole magnetic fields, they exhibit no detectable gyroresonant radiation, suggesting that these stars do not have hot, dense coronae. The binary RS CVn star UX Arietis exhibits variable emission at 6 cm wavelength on time scales ranging from 30 s to more than one hour.

Role of Key TYMS Polymorphisms on Methotrexate Therapeutic Outcome in Portuguese Rheumatoid Arthritis Patients

PubMed Central

Lima, Aurea; Seabra, Vítor; Bernardes, Miguel; Azevedo, Rita; Sousa, Hugo; Medeiros, Rui

2014-01-01

Background Therapeutic outcome of rheumatoid arthritis (RA) patients treated with methotrexate (MTX) can be modulated by thymidylate synthase (TS) levels, which may be altered by genetic polymorphisms in TS gene (TYMS). This study aims to elucidate the influence of TYMS polymorphisms in MTX therapeutic outcome (regarding both clinical response and toxicity) in Portuguese RA patients. Methods Clinicopathological data from 233 Caucasian RA patients treated with MTX were collected, outcomes were defined and patients were genotyped for the following TYMS polymorphisms: 1) 28 base pairs (bp) variable number tandem repeat (rs34743033); 2) single nucleotide polymorphism C>G (rs2853542); and 3) 6 bp sequence deletion (1494del6, rs34489327). Chi-square and binary logistic regression analyses were performed, using genotype and haplotype-based approaches. Results Considering TYMS genotypes, 3R3R (p = 0.005, OR = 2.34), 3RC3RG (p = 0.016, OR = 3.52) and 6bp− carriers (p = 0.011, OR = 1.96) were associated with non-response to MTX. Multivariate analysis confirmed the increased risk for non-response to MTX in 6bp− carriers (p = 0.016, OR = 2.74). Data demonstrated that TYMS polymorphisms were in linkage disequilibrium (p<0.00001). Haplotype multivariate analysis revealed that haplotypes harboring both 3R and 6bp− alleles were associated with non-response to MTX. Regarding MTX-related toxicity, no statistically significant differences were observed in relation to TYMS genotypes and haplotypes. Conclusion Our study reveals that TYMS polymorphisms could be important to help predicting clinical response to MTX in RA patients. Despite the potential of these findings, translation into clinical practice needs larger studies to confirm these evidences. PMID:25279663

Are genetic variations in OXTR, AVPR1A, and CD38 genes important to social integration? Results from two large U.S. cohorts.

PubMed

Chang, Shun-Chiao; Glymour, M Maria; Rewak, Marissa; Cornelis, Marilyn C; Walter, Stefan; Koenen, Karestan C; Kawachi, Ichiro; Liang, Liming; Tchetgen Tchetgen, Eric J; Kubzansky, Laura D

2014-01-01

Some evidence suggests that genetic polymorphisms in oxytocin pathway genes influence various social behaviors, but findings thus far have been mixed. Many studies have been based in small samples and there is possibility of publication bias. Using data from 2 large U.S. prospective cohorts with over 11,000 individuals, we investigated 88 SNPs in OXTR, AVPR1A, and CD38, in relation to social integration (measured as social connectedness in both binary and continuous forms and being continuously married). After correction for multiple testing only one SNP in CD38 (rs12644506) was significantly associated with social integration and that SNP predicted when using a dichotomized indicator of social connectedness (adjusted p=0.02), but not a continuous measure of social connectedness or the continuously married outcome. A significant gender-heterogeneous effect was identified in one OXTR SNP on dichotomized social connectedness; specifically, rs4686302 T allele was nominally associated with social connectedness in men, whereas the association direction was opposite in women (adjusted gender heterogeneity p=0.02). Furthermore, the rs53576 A allele was significantly associated with social connectedness only in women, and the effect magnitude was stronger in a dominant genetic model (adjusted p=0.003). In summary, our findings suggested that common genetic variants of OXTR, CD38, and AVPR1A are not associated with social integration as measured in this study using the simplified Berkman-Syme Social Network Index, but these findings and other work hint that effects may be modified by gender or other social experiences. Further work considering genetic pathways in relation to social integration may be more fruitful if these additional factors can be more comprehensively evaluated. Copyright © 2013 Elsevier Ltd. All rights reserved.

Are genetic variations in OXTR, AVPR1A, and CD38 genes important to social integration? Results from two large U.S. cohorts

PubMed Central

Chang, Shun-Chiao; Glymour, M Maria; Rewak, Marissa; Cornelis, Marilyn; Walter, Stefan; Koenen, Karestan C; Kawachi, Ichiro; Liang, Liming; Tchetgen, Eric Tchetgen; Kubzansky, Laura D.

2013-01-01

Some evidence suggests that genetic polymorphisms in oxytocin pathway genes influence various social behaviors, but findings thus far have been mixed. Many studies have been based in small samples and there is possibility of publication bias. Using data from 2 large U.S. prospective cohorts with over 11,000 individuals, we investigated 88 SNPs in OXTR, AVPR1A, and CD38, in relation to social integration (measured as social connectedness in both binary and continuous forms and being continuously married). After correction for multiple testing only one SNP in CD38 (rs12644506) was significantly associated with social integration and that SNP predicted when using a dichotomized indicator of social connectedness (adjusted p=0.02), but not a continuous measure of social connectedness or the continuously married outcome. A significant gender-heterogeneous effect was identified in one OXTR SNP on dichotomized social connectedness; specifically, rs4686302 T allele was nominally associated with social connectedness in men, whereas the association direction was opposite in women (adjusted gender heterogeneity p=0.02). Furthermore, the rs53576 A allele was significantly associated with social connectedness only in women, and the effect magnitude was stronger in a dominant genetic model (adjusted p=0.003). In summary, our findings suggested that common genetic variants of OXTR, CD38, and AVPR1A are not associated with social integration as measured in this study using the simplified Berkman-Syme Social Network Index, but these findings and other work hint that effects may be modified by gender or other social experiences. Further work considering genetic pathways in relation to social integration may be more fruitful if these additional factors can be more comprehensively evaluated. PMID:24209975

Application of advanced machine learning methods on resting-state fMRI network for identification of mild cognitive impairment and Alzheimer's disease.

PubMed

Khazaee, Ali; Ebrahimzadeh, Ata; Babajani-Feremi, Abbas

2016-09-01

The study of brain networks by resting-state functional magnetic resonance imaging (rs-fMRI) is a promising method for identifying patients with dementia from healthy controls (HC). Using graph theory, different aspects of the brain network can be efficiently characterized by calculating measures of integration and segregation. In this study, we combined a graph theoretical approach with advanced machine learning methods to study the brain network in 89 patients with mild cognitive impairment (MCI), 34 patients with Alzheimer's disease (AD), and 45 age-matched HC. The rs-fMRI connectivity matrix was constructed using a brain parcellation based on a 264 putative functional areas. Using the optimal features extracted from the graph measures, we were able to accurately classify three groups (i.e., HC, MCI, and AD) with accuracy of 88.4 %. We also investigated performance of our proposed method for a binary classification of a group (e.g., MCI) from two other groups (e.g., HC and AD). The classification accuracies for identifying HC from AD and MCI, AD from HC and MCI, and MCI from HC and AD, were 87.3, 97.5, and 72.0 %, respectively. In addition, results based on the parcellation of 264 regions were compared to that of the automated anatomical labeling atlas (AAL), consisted of 90 regions. The accuracy of classification of three groups using AAL was degraded to 83.2 %. Our results show that combining the graph measures with the machine learning approach, on the basis of the rs-fMRI connectivity analysis, may assist in diagnosis of AD and MCI.

THE QUASI-ROCHE LOBE OVERFLOW STATE IN THE EVOLUTION OF CLOSE BINARY SYSTEMS CONTAINING A RADIO PULSAR

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

Benvenuto, O. G.; De Vito, M. A.; Horvath, J. E., E-mail: adevito@fcaglp.unlp.edu.ar, E-mail: foton@iag.usp.br

We study the evolution of close binary systems formed by a normal (solar composition), intermediate-mass-donor star together with a neutron star. We consider models including irradiation feedback and evaporation. These nonstandard ingredients deeply modify the mass-transfer stages of these binaries. While models that neglect irradiation feedback undergo continuous, long-standing mass-transfer episodes, models including these effects suffer a number of cycles of mass transfer and detachment. During mass transfer, the systems should reveal themselves as low-mass X-ray binaries (LMXBs), whereas when they are detached they behave as binary radio pulsars. We show that at these stages irradiated models are in amore » Roche lobe overflow (RLOF) state or in a quasi-RLOF state. Quasi-RLOF stars have radii slightly smaller than their Roche lobes. Remarkably, these conditions are attained for an orbital period as well as donor mass values in the range corresponding to a family of binary radio pulsars known as ''redbacks''. Thus, redback companions should be quasi-RLOF stars. We show that the characteristics of the redback system PSR J1723-2837 are accounted for by these models. In each mass-transfer cycle these systems should switch from LMXB to binary radio pulsar states with a timescale of approximately one million years. However, there is recent and fast growing evidence of systems switching on far shorter, human timescales. This should be related to instabilities in the accretion disk surrounding the neutron star and/or radio ejection, still to be included in the model having the quasi-RLOF state as a general condition.« less

Photometric and Spectroscopic Analysis for the Determination of Physical Parameters of an Eclipsing Binary Star System

NASA Astrophysics Data System (ADS)

Reid, Piper

2013-01-01

A binary star system is a pair of stars that are bound together by gravity. Most of the stars that we see in the night sky are members of multiple star systems. A system of stars where one star passes in front of the other (as observed from Earth) on a periodic basis is called an eclipsing binary. Eclipsing binaries can have very short rotational periods and in all cases these pairs of stars are so far away that they can only be resolved from Earth as a single point of light. The interaction of the two stars serves to produce physical phenomena that can be observed and used to study stellar properties. By careful data collection and analysis is it possible for an amateur astronomer using commercial, low cost equipment (including a home built spectroscope) to gather photometric (brightness versus time) and spectroscopic (brightness versus wavelength) data, analyze the data, and calculate the physical properties of a binary star system? Using a CCD camera, tracking mount and telescope photometric data of BB Pegasi was collected and a light curve produced. 57 Cygni was also studied using a spectroscope, tracking mount and telescope to prove that Doppler shift of Hydrogen Balmer absorption lines can be used to determine radial velocity. The orbital period, orbital velocity, radius of each star, separation of the two stars and mass of each star was calculated for the eclipsing binary BB Pegasi using photometric and spectroscopic data and Kepler’s 3rd Law. These data were then compared to published data. By careful use of consumer grade astronomical equipment it is possible for an amateur astronomer to determine an array of physical parameters of a distant binary star system from a suburban setting.

New Results on Contact Binary Stars

NASA Astrophysics Data System (ADS)

He, J.; Qian, S.; Zhu, L.; Liu, L.; Liao, W.

2014-08-01

Contact binary star is a kind of close binary with the strongest interaction binary system. Their formations and evolutions are unsolved problems in astrophysics. Since 2000, our groups have observed and studied more than half a hundred of contact binaries. In this report, I will summarize our new results of some contact binary stars (e.g. UZ CMi, GSC 03526-01995, FU Dra, GSC 0763-0572, V524 Mon, MR Com, etc.). They are as follow: (1) We discovered that V524 Mon and MR Com are shallow-contact binaries with their period decreasing; (2) GSC 03526-01995 is middle-contact binary without a period increasing or decreasing continuously; (3) UZ CMi, GSC 0763-0572 and FU Dra are middle-contact binaries with the period increasing continuously; (4) UZ CMi, GSC 03526-01995, FU Dra and V524 Mon show period oscillation which may imply the presence of additional components in these contact binaries.

Solidification phenomena of binary organic mixtures

NASA Technical Reports Server (NTRS)

Chang, K.

1982-01-01

The coalescence rates and motion of liquid bubbles in binary organic mixtures were studied. Several factors such as temperature gradient, composition gradient, interfacial tension, and densities of the two phases play important roles in separation of phases of immiscible liquids. An attempt was made to study the effect of initial compositions on separation rates of well-dispersed organic mixtures at different temperatures and, ultimately, on the homogeneity of solidification of the immiscible binary organic liquids. These organic mixtures serve as models for metallic pseudo binary systems under study. Two specific systems were investigated: ethyl salicylate - diethyl glycol and succinonitrile - water.

Generalized Roche potential for misaligned binary systems - Properties of the critical lobe

NASA Technical Reports Server (NTRS)

Avni, Y.; Schiller, N.

1982-01-01

The paper considers the Roche potential for binary systems where the stellar rotation axis is not aligned with the orbital revolution axis. It is shown that, as the degree of misalignment varies, internal Lagrangian points and external Lagrangian points may switch their roles. A systematic method to identify the internal Lagrangian point and to calculate the volume of the critical lobe is developed, and numerical results for a wide range of parameters of binary systems with circular orbits are presented. For binary systems with large enough misalignment, discrete changes occur in the topological structure of the equipotential surfaces as the orbital phase varies. The volume of the critical lobe has minima, as a function of orbital phase, at the two instances when the secondary crosses the equatorial plane of the primary. In semidetached systems, mass transfer may be confined to the vicinity of these two instances.